Chevrolet - S 10 - Workshop Manual - 1992 - 1992

Page 1196 - Meets GM contamination sensitivity requirements - Self calibrating - Micro-processor controlled - Audio alarm alerts technician Other Refrigerant Identifiers are being advertised which may be available this A/C season. However, ONLY the Kent-Moore J 39851 R12 "Pureguard" meets General Motors' current specifications which ensure recovered refrigerant is compatible with General Motors vehicles and General Motors approved recovery systems. An R134a Pureguard Refrigerant Identifier is currently under development and is anticipated to be available in early 1995. The contamination of R134a refrigerant is not expected to be a concern until the program to retrofit R12 vehicles to R134a becomes more widely used. Future bulletins will be issued to address the recovery and disposal of contaminated refrigerant. Steering - Column Popping Noise Steering Column Bearing: All Technical Service Bulletins Steering - Column Popping Noise Group Ref.: Steering/Suspension Bulletin No.: 333210A Date: December, 1993 SUBJECT: STEERING COLUMN POPPING NOISE (REPLACE UPPER BEARING INNER RACE SEAT) MODELS: 1992-93 PASSENGER CARS EXCEPT CHEVROLET CAVALIER, GEO AND PONTIAC LEMANS 1992-93 LIGHT DUTY TRUCKS EXCEPT GEO TRACKER This bulletin is being re-published to add the labor time for Labor Operation Number E7310. Vehicles affected have TILT steering columns (round style) with the exception of the "W" series (square style). CONDITION: Some owners of vehicles with integral TILT steering columns may hear a pop noise when turning. The noise occurs specifically when the driver is making normal steering turns in either direction and generally when the steering wheel is returning to center. CAUSE: The upper bearing inner race seat under certain conditions may cause a pop noise. The part may have a burr on the inside skirt. CORRECTION: To verify that the upper bearing inner race seat is the cause of the pop noise in the steering column, use the following method: 1. Engage the park brake and start the engine. 2. Point the wheels of the vehicle straight ahead. 3. While listening for a pop noise, rotate the steering wheel in either direction to the wheel stop. Slowly return the wheel back to center. If the noise is not heard, drive the vehicle at a slow speed listening for the noise to occur. Important: When the steering column is warm, the pop noise will be more audible. 4. If a pop noise is heard, replace the upper bearing inner race seat with P/N 7815184. Return the steering wheel back to center with the wheels of the vehicle pointed straight ahead. Turn the ignition lock cylinder to "LOCK" position and then begin the repair. Refer to Section 3F5A/3F5B in the Service Manual to replace the upper bearing inner race seat. Parts are currently available from GMSPO. Labor Operation Number: E7310 Labor Time: 0.6 hrs. For GMC Truck ONLY, use: T7681 Labor Time: 0.4 hrs. (With SIR add .2 hrs.) Page 6305 5. Control assembly (49). INSTALL OR CONNECT 1. Cables (53) to the control assembly (49). 2. Vacuum connections to the control assembly (49). 3. Electrical connections to the control assembly (49). 4. Control assembly (49). 5. Screws (50). Page 4112 Page 6257 Removing Or Installing Shaft Seal 6. Fully engage the knurled tangs of Seal Remover/Installer J 23128-A into the recessed portion of the Seal by turning the handle clockwise. Remove the Seal from the compressor with a rotary-pulling motion. Discard the seal. The handle must be hand- tightened securely. Do not use a wrench or pliers. Page 5186 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 7560 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 977 Drive Belt: Technical Service Bulletins Engine - Serpentine Belt Chirp/Squeak or Premature Wear NUMBER: 93-153A-6B SECTION: 6B DATE: August 1993 CORPORATE REFERENCE NUMBER: 3661O1R SUBJECT: SERPENTINE BELT CHIRP/SQUEAKING OR PREMATURE WEAR (DIAGNOSE/REPLACE BELT) MODELS: 1992-93 G VANS 1990-93 M/L VANS AND S/T, C/K TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 93-153A-6B, DATED MARCH 1993. THE 1990-93 C/K TRUCKS HAVE BEEN ADDED. ALL COPIES OF 93-153-6B SHOULD BE DISCARDED. CONDITION: Some 1992-93 G-Vans with 4.3L (LB4), 5.OL (L03), 5.7L (L05), 1990-93 M/L Vans with 4.3L (LB4, L35, LU2), and 1990-93 C/K or S/T Trucks with 4.3L (LB4, L35), 5.0L (L03), or 5.7L (L05) engines may experience a chirping sound. a squeaking noise, or premature wear on the outer skin of the serpentine belt accessory drive. CAUSE/CORRECTION: The cause of the above conditions can be attributed to the following: "SQUEAKING NOISE" This condition typically occurs on vehicles equipped with air conditioning. The condition may be caused by a belt misalignment between the A/C compressor and the belt tensioner pulley. The belt misalignment causes the belt to rub against the front, rear, or inner edges of the A/C pulley grooves, creating a "squeaking" sound. For a multiple ribbed belt it is important that the grooves of the belt match the grooves in the pulleys. A mirror placed close to the pulley and belt may be helpful when inspecting the belt to pulley groove match. To verify alignment, place a straight edge or position a cord across 2 pulleys so they touch at all points. Turn each pulley one half revolution and recheck with the straight edge or cord. If contact is not made at all points check for a warped or bent shaft or, refer to the service manual (Section 6B-Engine Cooling) for proper inspection and adjustments. NOTE: Squeaking noise and chirping sounds should not be confused while diagnosing the concern. "Squeaking is more of a sound which is continuous in nature. "Chirping" is of short duration intermittent, and a high pitched sound. "CHIRPING SOUND" The cause of the chirping sound may be the result of contamination or paint in the pulley grooves. If contamination or paint is noticed, remove the serpentine belt using procedures in section 6B, (Engine Cooling) of the service manual. Remove all contamination or paint from all pulley grooves. A wire brush mounted on an electric drill can be used to perform this operation. Caution should be taken when using the wire brush. After completion of the cleaning operation, inspect all locations. The surfaces should be smooth and free from burrs and rough edges. Do not over buff, this may result in an out of round condition on the pulley. If the power steering pulley is suspect of causing the chirp sound, verify that the power steering pump pulley is aligned and flush to the power steering pump assembly, reference section 3B1 (Power Steering) and section 6B (Engine Cooling) of the service manual for proper inspection and adjustments. NOTE: Belt dressing is NOT to be used on the serpentine belt. This will only aggravate the chirping condition. "PREMATURE WEAR" This condition will occur on vehicles with air conditioning only. The condition can be identified by scuffing or marring of the outer belt skin or the belt ribs where a possible interference may take place. Page 8115 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 3863 Locations A/C And Heater Wiring Page 825 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 5827 1. The tire must be in the relaxed position when the repair unit is installed (Do not spread the beads excessively). Two-Piece Plug and Repair Units 1. If applicable, install the repair unit so that the alignment is correct. 2. Center the repair unit over the injury and stitch down thoroughly with the stitching tool, working from the center out. 3. Being careful not to stretch the plug material, cut the plug flush with the outer tread. Combination Repair/Plug Units 1. Pull the plug through the injury until the repair just reaches the liner. Stitch down thoroughly. 2. Follow the repair material manufacturer's recommendations for further installation instructions. 2. Consult your repair material supplier for the proper stitching tool. Safety Cage Page 7204 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: Customer Interest Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. A/C - Use of Alternate Refrigerants In CFC 12 Refrigerant: Technical Service Bulletins A/C - Use of Alternate Refrigerants In CFC 12 Number: 92-250-1A Section: 0A Date: AUGUST 1992 Corporate Bulletin No.: 231205 ASE No.: A7 Subject: USE OF ALTERNATE REFRIGERANTS IN CFC 12 REFRIGERANT MOBILE AIR CONDITIONERS Model and Year: GALL MODEL YEARS - ALL PASSENGER CARS AND TRUCKS INCLUDING GEO A number of inquiries have been received concerning the use of "alternate refrigerants" as a replacement for R-12 refrigerant in General Motors air conditioning systems. Regardless of any advertised claims, there are currently no substitutes for refrigerant R-12 approved by General Motors. At the present time, only new or recycled R-12 is approved for use in General Motors R-12 air conditioning systems. Based on studies performed to date, the use of "alternate refrigerants" in General Motors R-12 air conditioning systems may result in higher system pressures, higher leak rates or incompatibility with drying and sealing materials. System performance and reliability may also be affected. Service equipment manufacturers have indicated that cross-contaminating R-12 recovery/recycling equipment with "alternate refrigerants" may damage the equipment. General Motors supports the Society of Automotive Engineers recommended service procedures for recovery and recycling of R-12. The use of known "alternate refrigerants" without proper service practices for identifying vehicle systems containing these "alternate refrigerants" and dedicated recovery equipment to service those vehicles will contaminate the recycled supply of R-12 refrigerant. Contamination of the recycled R-12 refrigerant makes the refrigerant unusable for recharging air conditioning systems and could jeopardize the recycling program. At the present time, General Motors has not approved any "alternate refrigerant" for R-12 in R-12 air conditioning systems. Therefore, R-12 systems should continue to be serviced with new or recycled R-12 only. Page 3074 Speed Sensor Components Do Not Operate Properly Interior - Itch Noise From Windshield Pillar Area Instrument Cluster / Carrier: Customer Interest Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. With A-6 Compressor Compressor Clutch Coil: Service and Repair With A-6 Compressor Remove or Disconnect Tool Required: J 6435 External Snap Ring Pliers 1. Clutch plate and hub assembly (2). 2. Pulley (6). - Mark or scribe the location of the clutch coil (8) to terminal on the compressor front head (16). Page 6461 - Install the blower switch knob. 2. Control cables (60 and 65). 3. Electrical connection (82). 4. Control assembly (63). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 5. Screws (64). - Check circuit operation. Page 8134 Brake Lamp: Description and Operation Voltage is supplied at all times through the STOP-HAZ Fuse to the Brake Switch. When the brake pedal is depressed, the contacts in the Brake Switch close. Voltage is supplied through the Turn Switch Assembly tot he LH and RH Stoplamp, and the Stoplamps lights. If a Turn Signal is on, the Stoplamp on that side will flash as a Turn Signal. The other Stoplamp will serve as a Stoplamp. Page 4554 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 3825 Case: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Accumulator Cover To Case ............................................................................................................... ................................................................................. 8 Case Extension To Case ................................ .............................................................................................................................................................. ....... 26 Auxiliary Valve Body To Case ................................................................................................ ............................................................................................ 8 Bellhousing To Case ........................... .............................................................................................................................................................. ................. 55 Pump Assembly To Case ............................................................................................. ...................................................................................................... 18 Solenoid Assembly To Case ... .............................................................................................................................................................. .............................. 18 Spacer Plate Support To Case ........................................................................ ...................................................................................................................... 8 Transmission Oil Pan To Case ............................................................................................................................................... .............................................. 8 Page 5967 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Page 185 ECM QDR Check Procedure Page 1771 Drive Belt: Technical Service Bulletins Engine - Serpentine Belt Chirp/Squeak or Premature Wear NUMBER: 93-153A-6B SECTION: 6B DATE: August 1993 CORPORATE REFERENCE NUMBER: 3661O1R SUBJECT: SERPENTINE BELT CHIRP/SQUEAKING OR PREMATURE WEAR (DIAGNOSE/REPLACE BELT) MODELS: 1992-93 G VANS 1990-93 M/L VANS AND S/T, C/K TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 93-153A-6B, DATED MARCH 1993. THE 1990-93 C/K TRUCKS HAVE BEEN ADDED. ALL COPIES OF 93-153-6B SHOULD BE DISCARDED. CONDITION: Some 1992-93 G-Vans with 4.3L (LB4), 5.OL (L03), 5.7L (L05), 1990-93 M/L Vans with 4.3L (LB4, L35, LU2), and 1990-93 C/K or S/T Trucks with 4.3L (LB4, L35), 5.0L (L03), or 5.7L (L05) engines may experience a chirping sound. a squeaking noise, or premature wear on the outer skin of the serpentine belt accessory drive. CAUSE/CORRECTION: The cause of the above conditions can be attributed to the following: "SQUEAKING NOISE" This condition typically occurs on vehicles equipped with air conditioning. The condition may be caused by a belt misalignment between the A/C compressor and the belt tensioner pulley. The belt misalignment causes the belt to rub against the front, rear, or inner edges of the A/C pulley grooves, creating a "squeaking" sound. For a multiple ribbed belt it is important that the grooves of the belt match the grooves in the pulleys. A mirror placed close to the pulley and belt may be helpful when inspecting the belt to pulley groove match. To verify alignment, place a straight edge or position a cord across 2 pulleys so they touch at all points. Turn each pulley one half revolution and recheck with the straight edge or cord. If contact is not made at all points check for a warped or bent shaft or, refer to the service manual (Section 6B-Engine Cooling) for proper inspection and adjustments. NOTE: Squeaking noise and chirping sounds should not be confused while diagnosing the concern. "Squeaking is more of a sound which is continuous in nature. "Chirping" is of short duration intermittent, and a high pitched sound. "CHIRPING SOUND" The cause of the chirping sound may be the result of contamination or paint in the pulley grooves. If contamination or paint is noticed, remove the serpentine belt using procedures in section 6B, (Engine Cooling) of the service manual. Remove all contamination or paint from all pulley grooves. A wire brush mounted on an electric drill can be used to perform this operation. Caution should be taken when using the wire brush. After completion of the cleaning operation, inspect all locations. The surfaces should be smooth and free from burrs and rough edges. Do not over buff, this may result in an out of round condition on the pulley. If the power steering pulley is suspect of causing the chirp sound, verify that the power steering pump pulley is aligned and flush to the power steering pump assembly, reference section 3B1 (Power Steering) and section 6B (Engine Cooling) of the service manual for proper inspection and adjustments. NOTE: Belt dressing is NOT to be used on the serpentine belt. This will only aggravate the chirping condition. "PREMATURE WEAR" This condition will occur on vehicles with air conditioning only. The condition can be identified by scuffing or marring of the outer belt skin or the belt ribs where a possible interference may take place. Page 13 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Coolant Temperature Switch Engine Wiring, LH Side A/T - Intermittent Slip, Downshift, or Busy Cycling TCC Torque Converter Clutch: All Technical Service Bulletins A/T - Intermittent Slip, Downshift, or Busy Cycling TCC Number: 92-42-7A Section: 7A Date: NOV. 1991 Corporate Bulletin No.: 167105 ASE No.: A2 Subject: INTERMITTENT TRANSMISSION DOWNSHIFT, SLIP OR BUSY/CYCLING TCC Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSMISSION Some owners may comment that their vehicle is experiencing one or more of the following transmission conditions: - Intermittent slipping. - Intermittent downshift followed by an upshift, both with no apparent reason. - Busyness or cycling of the TCC at steady throttle conditions and level roadway. The cooling fan operates when the thermostat on the fan clutch reaches a preset temperature. When this temperature is reached, the fan engages to draw additional air through the radiator and lower the engine temperature. When the cooling fan engages, noise increases and may sound very similar to an increase in engine RPM due to transmission downshift, slipping or TCC cycling. When engine temperature lowers to a preset point the fan clutch will disengage. When the cooling fan disengages, noise levels will decrease and may sound very similar to a decrease in engine RPM. The type of concern described above requires further definition and the customer should be asked several questions: - Is the situation more pronounced at higher vehicle loads or pulling a trailer? - Do warmer ambient temperatures make the situation more pronounced as well? If the customer's responses indicate that both of these conditions apply, and your observation of the vehicle confirms a properly operating vehicle, provide the customer the vehicle operating description included in this bulletin. Further action may not be necessary. A service procedure follows if further definition is required. SERVICE PROCEDURE: When attempting to diagnose an intermittent transmission downshift, slip or busy/cycling TCC: 1. Check fluid level and condition as outlined in section 7A of the appropriate service manual. 2. Test drive the vehicle under the conditions described by the customer (ambient temperature, engine coolant temperature, trailering, etc.). It may be necessary to partially restrict airflow to the radiator to raise engine coolant temperature to match customer conditions. 3. Monitor engine RPM and engine coolant temperature using a scan tool. 4. Listen for an apparent increase in engine RPM. If engine RPM sounds like it increases, check the scan tool RPM and coolant temperature readings. If the noise increase is due to engagement of the fan the engine RPM will not increase and engine coolant temperature will begin to decrease after the fan engages. As the fan runs the engine coolant temperature will drop and the fan will disengage reducing noise levels, engine RPM will not decrease. This cycle will repeat as engine coolant temperature again rises. If the above procedure shows the condition to be cooling fan related, no further action is necessary. The vehicle should be returned to the customer and the condition explained. If the above procedure shows the condition to be other than cooling fan related, refer to section 7A of the appropriate service manual for transmission diagnosis information. Intermittent Transmission Downshift All light duty trucks are equipped with a thermostatic engine cooling fan. This fan is designed to provide greater fuel efficiency and quieter operation Page 3114 Linear EGR Valve Central MFI Page 5187 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Wheels (Steel) - Damage Due to Improper Mounting Wheels: All Technical Service Bulletins Wheels (Steel) - Damage Due to Improper Mounting Number: 92-232-3E Section: 3E Date: JUNE 1992 Corporate Bulletin No.: 233002 ASE No.: A4 Subject: AVOIDING DAMAGE TO STEEL WHEELS FROM IMPROPER WHEEL/TIRE CHANGING TECHNIQUES Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH STEEL WHEELS It is important to use proper procedures to prevent damage to either the tire mounting surface or the wheel mounting holes. Damage can result from the improper wheel attachment or tire mounting techniques on vehicles with steel wheels. 1. IMPROPER TIRE CHANGING TECHNIQUES: It takes about 70 seconds for the air to completely exhaust from a large tire. If the technician doesn't wait this amount of time after removing the valve core, the bead breaker on the tire change could put enough force on the tire to bend the wheel at the mounting surface. Such damage can result in vibration, shimmy, and under severe usage (i.e. police vehicle) lead to cracking. 2. OVER TORQUING OF THE WHEEL NUTS: The service specification for wheel nuts is listed in the Service Manuals. Some wheels have been observed with wheel nuts that were over torqued by as much as 50 percent. This may damage the wheel mounting holes and may also lead to cracks. I. PROPER TIRE CHANGING TECHNIQUES: Completely deflate the tire before attempting to break the tire bead loose. MOUNTING SURFACE CHECKING PROCEDURE Page 4412 Case: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Transmission Case Bolts ..................................................................................................................... .................................................................... 27 ft. lbs. Page 650 Oxygen Sensor Location Page 7625 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 1467 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Door Window Motor RH Door Harness (LH Typical) Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: All Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. W/Integral Reservoir Power Steering Pump: Description and Operation W/Integral Reservoir The hydraulic pump is a submerged, vane-type design. Submerged pumps have a housing and internal parts inside the reservoir and operate submerged in fluid. There are two openings at the rear of the pump housing. The larger opening contains the cam ring, pressure plate, thrust plate, rotor and vane assembly and the end plate. The smaller opening contains the pressure line union, flow control valve, and spring. The flow control orifice is part of the pressure line union. The pressure relief valve, located inside the flow control valve, limits pump pressure. Page 5547 Frame Angle Measurement (Express / Savana Only) ........ Page 5855 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Page 1774 Drive Belt: Technical Service Bulletins Engine - Serpentine Belt Squeak/Chirp or Premature Wear BULLETIN NUMBER: 93-6A-108 SECTION: 6A Engine Mechanical NUMBER: 6 CORPORATE REFERENCE NUMBER: 366101R DATE: August 1993 SUBJECT: SERPENTINE BELT CHIRP/SQUEAKING OR PREMATURE WEAR (DIAGNOSE/REPLACE BELT) MODELS: 1992-93 G VANS 1990-93 M/L VANS AND S/T, C/K TRUCKS THIS BULLETIN IS BEING REVISED TO ADD 1990-93 MODEL YEAR C/K AND S/T TRUCKS WITH 4.3L (LB4, L35), 5.0L (L03), OR 5.7L (L05) ENGINES. CONDITION: Some 1992-93 G-Vans with 4.3L (LB4), 5.0L (L03), 5.7L (L05), 1990-93 M/L Vans with 4.3L (LB4, L35, LU2), and 1990-93 C/K or S/T Trucks with 4.3L (LB4, L35), 5.0L (L03), or 5.7L (L05) engines may experience a chirping sound, a squeaking noise, or premature wear on the outer skin of the serpentine belt accessory drive. CAUSE/CORRECTION: The cause of the above conditions can be attributed to the following: "SQUEAKING NOISE" This condition typically occurs on vehicles equipped with air conditioning. The condition may be caused by a belt misalignment between the A/C compressor and the belt tensioner pulley. The belt misalignment causes the belt to rub against the front, rear, or inner edges of the A/C pulley grooves, creating a "squeaking" sound. For a multiple ribbed belt it is important that the grooves of the belt match the grooves in the pulleys. A mirror placed close to the pulley and belt may be helpful when inspecting the belt to pulley groove match. To verify alignment, place a straight edge or position a cord across 2 pulleys so they touch at all points. Turn each pulley one half revolution and recheck with the straight edge or cord. If contact is not made at all points check for a warped or bent shaft or, refer to the service manual (Section 6B-Engine Cooling) for proper inspection and adjustments. **Note: Squeaking noise and chirping sounds should not be confused while diagnosing the concern. "Squeaking" is more of a sound which is continuous in nature. "Chirping" is of short duration intermittent, and a high pitched sound. "CHIRPING SOUND" The cause of the chirping sound may be the result of contamination or paint in the pulley grooves. If contamination or paint is noticed, remove the serpentine belt using procedures in section 6B, (Engine Cooling) of the service manual. Remove all contamination or paint from all pulley grooves. A wire brush mounted on an electric drill can be used to perform this operation. Caution should be taken when using the wire brush. After completion of the cleaning operation, inspection all locations. The surfaces should be smooth and free from burrs and rough edges. Do not over buff, this may result in out of round condition of the pulley. If the power steering pulley is suspect of causing the chirp sound, verify that the power steering pump pulley is aligned and flush to the power steering pump assembly, reference section 3B1 (Power Steering) and section 6B (Engine Cooling) of the service manual for proper inspection on adjustments. **Note: Belt dressing is NOT to be used on the serpentine belt. This will only aggravate the chipping condition. "PREMATURE WEAR" This condition will occur on vehicles with air conditioning only. The condition can be identified by scuffing or marring of the outer belt skin or the belt ribs where a possible interference may take place. Locations Cruise Controller: Locations Cruise Control Components, Near Steering Column. Under LH Side Of I/P Initial Inspection and Diagnostic Overview Vanity Lamp: Initial Inspection and Diagnostic Overview 1. Check condition of RADIO Fuse. Locations Engine Wiring, LH Side Page 163 Convenience Center (with Digital Cluster) 2 - Pinion Carrier Bearings: Adjustments 2 - Pinion Fig. 3 Installing shims To adjust differential side bearing preload, change thickness of right and left shims equally so original backlash is not disturbed. 1. Ensure side bearing surfaces are clean and free of burrs. 2. Apply suitable lubricant to side bearings. If original bearings are to be reused, original outer races should also be used. 3. Install differential case in carrier, with bearing outer races in position. 4. Install left bearing cap and cap attaching bolts loosely so case may be moved during adjustment. 5. Measure original spacers and subtract .004 inch from each reading. Use caution not to interchange right and left spacers. 6. Select a service spacer for each side equal to thickness of original shim minus .004 inch, then install shim as shown in Fig. 3. Ensure flat edge of spacer faces against housing. 7. At this point, bearings should have no play and no drag (zero preload). If zero preload is not present, shims should be added or removed equally from both sides as necessary. 8. Check case for zero endplay using a suitable dial indicator. If shim installation causes excessive pinion to ring gear clearance, select thinner left shim and add difference to right side. Keep total shim thickness at a value equal to that obtained in step 6. 9. Install both bearing caps and cap attaching bolts. Torque bolts 40 ft. lbs. Fig. 4 Gear tooth contact pattern check 10. If pinion was not removed, check backlash and tooth pattern as follows: a. Apply suitable marking compound on ring gear teeth. Page 3654 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 7111 Time Allowance: See Chants NOTE: The time allowances provided on the chart include the hardware removal and installation (as indicated by the list guidelines), the masking and unmasking of the vehicle, stripping of the surface (as indicated by the guidelines), the refinish (and colorcoat when required), mix time for primer/ paint (and clearcoat when required), finesse/polish where required, washing and preparing the vehicle for delivery. OPERATION DESCRIPTION: PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER, REFINISH ENTIRE BODY ABOVE BODY SIDE MOLDINGS. PAINT TERM DEFINITIONS Following are definitions of paint repair terms used in this bulletin: Basecoat: A color topcoat that requires a clear topcoat over it. Break line: A natural dividing line on Page 7685 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 2902 Engine Control Module: Service and Repair Engine Control Module (ECM) Replacement When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure. 1. Disconnect battery ground cable. 2. Remove right side kick panel, then disconnect two ECM electrical connectors. 3. Remove ECM mounting hardware. 4. Remove ECM from passenger compartment. 5. Reverse procedure to install. Page 419 Figure 7 Figure 8 Figure 9 Figure 10 Locations Turn And Hazard Lamp Flashers Page 4590 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 4859 Symbol Identification Page 4327 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure that pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. When endplay is reduced to zero, check pinion bearing preload by rotating pinion with suitable torque wrench. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Disassembly Fig. 9 Drive Pinion Removal Fig. 10 Pinion Straddle Bearing Removal 1. Clamp pinion assembly in vise taking care not to damage housing or gear. 2. Hold driveshaft flange with suitable tool, then remove pinion nut and washer. 3. Remove driveshaft flange from pinion shaft using suitable puller. 4. Support housing in press as shown in Fig. 9, and press pinion from housing. Do not allow pinion to drop on floor. 5. Separate pinion flange, oil seal, front bearing and bearing retainer, driving seal from housing with suitable drift. 6. Remove bearing races from housing using suitable drift and place front bearing race with bearing. 7. Press rear bearing from pinion and place bearing with race. 8. Remove straddle bearing from axle housing using suitable drift, Fig. 10. 9. Inspect components keeping all components in order, and replace as needed. Assembly & Preload Page 5272 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 3996 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Locations Upshift Indicator: Locations Instrument cluster. Page 4882 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 1198 Retrofit Requirements The customer should be reminded that there is NO requirement in the U.S. to retrofit any vehicle produced with R-12. Vehicles built with R-12 can be serviced with R-12 as long as it is available (except in certain Canadian Provinces). GM has taken steps to extend the supply of R-12 and recommends that all R-12 vehicles continue to be serviced with R-12 as long as it is available. Training Video Before doing a retrofit the first time, it is recommended that you view the Certified Plus Training Video, Program number 51010.15, "R-134a Retrofit for GM Cars and Trucks". Table of Contents A. Retrofit Procedure 1. Inspect Condition of Vehicle 2. Recover the R-12 (new method) 3. Install the service port conversion fittings 4. Install any additional parts needed 5. Evacuate and recharge with new PAG or V5 retrofit oil and R-134a 6. Install the retrofit label Platform Details Compressor Replacement Chart B. General Information 1. Performance 2. Leakage 3. Desiccant 4. Improved Cooling Performance 5. PAG or V5 Oil Compatibility 6. Refrigerant Oil Level Page 6910 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 8195 Symbol Identification Page 7618 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 6659 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 7352 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Electrical Specifications Throttle Position Sensor: Electrical Specifications The throttle position sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Page 7643 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 8650 Front Door Window Glass: Technical Service Bulletins Body - Side Window Chipping Information INFORMATION Bulletin No.: 06-08-64-001B Date: October 20, 2009 Subject: Information on Side Door Window Glass Chipping Caused by Hanging Vehicle Key Lock Box Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add vehicles and model years and to include all types of door window glass. Please discard Corporate Bulletin Number 06-08-64-001A (Section 08 - Body & Accessories). - In several warranty parts review cases, side door window glass was observed with a chip or chips on the top side of the window glass. Dealer contacts confirmed that they use a vehicle key lock box on the front side door window glass. - A random selection of side door glass returns will be conducted to confirm adherence. If a side door glass is discovered with a chip or chips in the location previously described, the side door glass will be returned to the dealership for debit. Example of Side Door Glass - DO NOT place a vehicle key lock box on a side door window glass. Page 5665 Fig. 1 Exploded view of power steering gear Fig. 2 Rack piston plug removal Fig. 3 Bearing removal Refer to Fig. 1, when performing the following procedures. 1. Pry retaining ring out of housing groove with a screwdriver. 2. Turn stub shaft to the left until plug on opposite end is forced out of cylinder, then remove seal. 3. Remove plug from rack piston, Fig. 2. Page 7730 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 969 Valve Clearance: Adjustments VALVE ADJUSTMENT The VIN W engine does NOT have adjustable valve lash. When servicing the valve train requires removing and re-installing the rocker arms, tighten the rocker arm nuts to 27 Nm (20 ft. lbs.). Page 1222 Refrigerant: Specifications REFRIGERANT AND OIL CAPACITY 1. Refrigerant-12................................................................................................................................... ............................................... 1.134kg (2.5 lbs.). CAUTION: Overcharging a system may allow liquid Refrigerant-12 to get into the compressor, causing compressor noise and damage. Undercharging will cause insufficient cooling. 2. 525 Viscosity Refrigerant oil - R-4 Compressor ................................................................................................................................ ...................................... 236 ml (8.0 fl. oz.). Fuel System - TOP TIER Detergent Gasoline (Canada) Fuel: All Technical Service Bulletins Fuel System - TOP TIER Detergent Gasoline (Canada) INFORMATION Bulletin No.: 05-06-04-022G Date: October 27, 2010 Subject: TOP TIER Detergent Gasoline Information and Available Brands (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - Canada ONLY Models: 2011 and Prior GM Passenger Cars and Trucks (Canada Only) Supercede: This bulletin is being revised to update the model years and include an additional gasoline brand as a TOP TIER source. Please discard Corporate Bulletin Number 05-06-04-022F (Section 06 - Engine/Propulsion System). In the U.S., refer to the latest version of Corporate Bulletin Number 04-06-04-047I. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by the Canadian General Standards Board (CGSB). Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. Intake valve: 16,093 km (10,000 mi) with TOP TIER Detergent Gasoline Intake valve: 16,093 km (10,000 mi) with Minimum Additive recommended by the CGSB Top Tier Fuel Availability Chevron was the first to offer TOP TIER Detergent Gasoline in Canada. Shell became the first national gasoline retailer to offer TOP TIER Detergent Gasoline across Canada. Petro-Canada began offering TOP TIER Detergent Gasoline nationally as of October 1, 2006. Sunoco began offering TOP TIER Detergent Gasoline in March of 2007. Esso began offering TOP TIER Detergent Gasoline in May of 2010. Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: All Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Page 4625 1. Begin by opening the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (figure 2). 2. Attach the valve pressure bleeding tool J39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (figure 3). Tighten tool J39177 only finger tight. NOTE: It is not necessary to attach bleeding tool J39177 to the combination valve when using the manual bleed procedure. 3. Bleed each wheel in the following sequence: - Right rear - Left rear - Right front - Left front NOTE: Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. NOTE: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 4. Slowly apply the brake pedal one time and hold. 5. Loosen the bleeder valve to purge the air from the wheel cylinder/caliper. 6. Tighten the bleeder valve and slowly release the pedal. 7. Wait 15 seconds. 8. Be sure to check the master cylinder fluid level after 4-5 strokes to avoid running dry. 9. Repeat steps 4 through 8, until all air is purged from the wheel cylinder/caliper. NOTE: It may be necessary to repeat this sequence as many as 15 to 20 times per wheel. 10. Fill the master cylinder to the proper level and replace lid. 11. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs.in.). 12. Remove the valve pressure bleeding tools J39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 13. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. IMPORTANT: DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 14. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. IMPORTANT: DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 15. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs.in.). 16. Fill the master cylinder to the proper level with brake fluid. 17. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. IMPORTANT: MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 18. Repeat the entire brake bleed procedure if necessary. Warranty Information LABOR OP. MODEL H0700 S/T H0700 M/L H0700 C/K H0700 G Use applicable labor time guide for labor hours. Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Page 980 Drive Belt: Technical Service Bulletins Engine - Serpentine Belt Squeak/Chirp or Premature Wear BULLETIN NUMBER: 93-6A-108 SECTION: 6A Engine Mechanical NUMBER: 6 CORPORATE REFERENCE NUMBER: 366101R DATE: August 1993 SUBJECT: SERPENTINE BELT CHIRP/SQUEAKING OR PREMATURE WEAR (DIAGNOSE/REPLACE BELT) MODELS: 1992-93 G VANS 1990-93 M/L VANS AND S/T, C/K TRUCKS THIS BULLETIN IS BEING REVISED TO ADD 1990-93 MODEL YEAR C/K AND S/T TRUCKS WITH 4.3L (LB4, L35), 5.0L (L03), OR 5.7L (L05) ENGINES. CONDITION: Some 1992-93 G-Vans with 4.3L (LB4), 5.0L (L03), 5.7L (L05), 1990-93 M/L Vans with 4.3L (LB4, L35, LU2), and 1990-93 C/K or S/T Trucks with 4.3L (LB4, L35), 5.0L (L03), or 5.7L (L05) engines may experience a chirping sound, a squeaking noise, or premature wear on the outer skin of the serpentine belt accessory drive. CAUSE/CORRECTION: The cause of the above conditions can be attributed to the following: "SQUEAKING NOISE" This condition typically occurs on vehicles equipped with air conditioning. The condition may be caused by a belt misalignment between the A/C compressor and the belt tensioner pulley. The belt misalignment causes the belt to rub against the front, rear, or inner edges of the A/C pulley grooves, creating a "squeaking" sound. For a multiple ribbed belt it is important that the grooves of the belt match the grooves in the pulleys. A mirror placed close to the pulley and belt may be helpful when inspecting the belt to pulley groove match. To verify alignment, place a straight edge or position a cord across 2 pulleys so they touch at all points. Turn each pulley one half revolution and recheck with the straight edge or cord. If contact is not made at all points check for a warped or bent shaft or, refer to the service manual (Section 6B-Engine Cooling) for proper inspection and adjustments. **Note: Squeaking noise and chirping sounds should not be confused while diagnosing the concern. "Squeaking" is more of a sound which is continuous in nature. "Chirping" is of short duration intermittent, and a high pitched sound. "CHIRPING SOUND" The cause of the chirping sound may be the result of contamination or paint in the pulley grooves. If contamination or paint is noticed, remove the serpentine belt using procedures in section 6B, (Engine Cooling) of the service manual. Remove all contamination or paint from all pulley grooves. A wire brush mounted on an electric drill can be used to perform this operation. Caution should be taken when using the wire brush. After completion of the cleaning operation, inspection all locations. The surfaces should be smooth and free from burrs and rough edges. Do not over buff, this may result in out of round condition of the pulley. If the power steering pulley is suspect of causing the chirp sound, verify that the power steering pump pulley is aligned and flush to the power steering pump assembly, reference section 3B1 (Power Steering) and section 6B (Engine Cooling) of the service manual for proper inspection on adjustments. **Note: Belt dressing is NOT to be used on the serpentine belt. This will only aggravate the chipping condition. "PREMATURE WEAR" This condition will occur on vehicles with air conditioning only. The condition can be identified by scuffing or marring of the outer belt skin or the belt ribs where a possible interference may take place. Page 7516 Symbol Identification Page 7062 The AFFECTED AREAS MAY REQUIRE RECLEARCOATING/COLORCOATING OR REFINISHING. 8. In any case, once the proper repairs have been made, the final step in the repair process involves polishing the vehicle. A WORD ABOUT CLEARCOAT THICKNESS The clearcoat on the vehicle is typically 1.5 to 2.0 mils thick (one mil equals .001" or 1/1,000 of an inch). At least one mil thickness is required to provide lasting protection to the vehicle basecoat. PAINT GAGES The best way to accurately measure how much clearcoat has been removed is to use a paint gage before, during and after the sanding process. Paint gages measure the total thickness of the finish and when used, can determine how much clearcoat has been removed during the repair process. Paint gages range from magnetic pull types to sophisticated electronic types, are available from a variety of sources, and can cost from $30 to $1800. The older magnetic type gages, at best, a +/- 5% accuracy range and are not sensitive enough to detect removal of .5 mil clearcoat. The newer type magnetic gages have improved accuracy ranges. Most gages are confined to checking either a ferrous metal (steel) or non-ferrous metal (aluminum) panels. At this time, there are no viable gages for reading film thickness on non-metallic panels. A more sophisticated gage is the digital Elcometer 300 fn Paint Thickness gage (or equivalent). It has an ability to read film thickness on both ferrous and non-ferrous metal panels. This instrument has an accuracy range of +/- 1% and has thickness standards included for recalibration. Approximate cost = $1750. An alternative (for use on steel panels only) would be the digital Elcometer 246 model, or equivalent. This gage has a +/- 3% accuracy range and include thickness standards for recalibration. Approximate cost - $575. REPAIRING RAIL DUST DAMAGE Rail dust damage comes from the tiny iron particles produced from the friction between the train wheels and the track. It can also be deposited on vehicles if stored near any operation producing iron dust (steel ore yards, etc.). This dust can either lay on top of, or embed into the paint surface. It is usually diagnosed as; bumps in the paint surface OR - rust colored spots in the paint. PROCEDURE: 1. Wash the vehicle with soap and water, dry it and clean the affected area with wax and grease remover. 2. Keeping the vehicle in a cool or shaded area, rinse the surface with cold water. CAUTION: RAIL DUST REMOVER (OXALIC ACID) IS AN ACIDIC SUBSTANCE CONTAINING CHEMICALS THAT WILL BREAK DOWN THE IRON PARTICLES EMBEDDED IN THE FINISH. WHEN WORKING WITH IT, USE THE NECESSARY SAFETY EQUIPMENT, INCLUDING GLOVES AND GOGGLES. FOLLOW THE MANUFACTURER'S DIRECTIONS CLOSELY BECAUSE IT MAY REQUIRE SPECIAL HANDLING AND DISPOSAL. 3. Soak several terry cloth towels in a container of rail dust remover solution and, after the damaged areas have been rinsed with cold water, lay the wet towels on the damaged areas. 4. Allow the towels to remain in place for 20 minutes, keeping them moist by spraying with water and not allowing to dry on the surface of the vehicle. 5. After 20 minutes of applying the towels, remove them and rinse the area thoroughly with cold water. Inspect the affected area to ensure the dust has been removed. Use both touch (feeling for bumpy surface) and sight (magnifying glass for close inspection). 6. If upon inspection some particles are still present, the process of applying the towels can be repeated 3 times. 7. Select a test area and hand wet sand with American ultra fine 1,500 grit to 2,000 grit sandpaper to repair damage (surface pitting from dust). a. Use ample amounts of water. b. Go slow to prevent removing too much clearcoat. NOTICE: USE A PAINT GAGE TO DETERMINE THE AMOUNT OF CLEARCOAT REMOVED. IF TOO MUCH HAS BEEN REMOVED, ADDITIONAL CLEARCOAT WILL HAVE TO BE APPLIED. IF RAIL DUST HAS PENETRATED INTO THE BASECOAT, THE PANEL REQUIRES REFINISHING. MAKE SURE ALL RAIL DUST HAS BEEN REMOVED PRIOR TO REFINISHING OR THE RUST SPOTS WILL RETURN, CAUSING CUSTOMER COMEBACKS. 8. If the damage has been repaired, complete the repair to the entire panel. 9. Once the damage has been repaired, the final step in the repair process involves polishing the vehicle. PREVENTING INDUSTRIAL FALLOUT DAMAGE Page 8353 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 6195 Install or Connect 1. Place the Pulley Rotor on the J 21352-A Support Block to fully support the rotor hub during bearing installation (Fig. 19). Do not support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using Puller and Bearing Installer J 9481-A with Universal Handle J 29886, drive the bearing fully into hub (Fig. 19). The Installer will apply force to the outer race of the bearing if used as shown. 3. Place Bearing Staking Guide 3 33019-1 and Bearing Staking Pin J 33019-2 in the hub bore as shown in Figure 20. Shift the rotor and bearing assembly on the J 21352-A Support Block to give full support of the hub under the staking pin location. A heavy duty rubber band may be used to hold the stake pin in the guide (Fig. 20), and the stake pin should be properly positioned in the guide after each impact on the pin. 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to, but not touching, the bearing. Stake three (3) places 120° apart as shown in Figure 21. NOTICE:, The stake metal should not contact the outer race of the bearing to prevent the possibility of distorting the outer race. Page 5399 Fuse Block Details Page 7736 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Fuel System - Factors That Affect Economy/Mileage Fuel: Customer Interest Fuel System - Factors That Affect Economy/Mileage Number: 93-96-6C Section: 6C Date: FEB. 1993 Corporate Bulletin No.: 306502 ASE No.: A1, A8 Subject: FACTORS THAT AFFECT FUEL ECONOMY Model and Year: ALL YEARS ALL MODELS BACKGROUND INFORMATION: EPA fuel economy estimates are posted on the fuel economy label of all new vehicles. The only intended use of these values is for comparison among the different vehicles. Fuel economy estimates are generated from data taken during a laboratory test using pre-production prototype vehicles under extremely controlled conditions using a professional driver, with the vehicle operating on an instrument similar to a treadmill. The comparisons of current vehicle fuel economy to the EPA fuel economy estimates is a misuse of the information and should be discouraged. The EPA GAS MILEAGE GUIDE, available at each dealership, points out that the actual mileage when driving a vehicle may differ considerably from the estimated mileage. The guide also describes how vehicles are tested under identical conditions to insure the results can be compared with confidence. The EPA GAS MILEAGE GUIDE also points out that city fuel economy estimate simulates a 7.5 mile, stop-and-go trip with an average speed of 20 mph. The trip takes 23 minutes and has 18 stops. About 18 percent of the time is spent idling, as in waiting at traffic lights or in rush hour traffic. Two kinds of engine starts are used - the cold start, which is similar to starting a car in the morning after it has been parked all night - and the hot start, similar to restarting a vehicle after it has been warmed up, driven and stopped for a short time. The test to determine the highway fuel economy estimate represents a mixture of "non-city" driving. Segments corresponding to different kinds of rural roads and interstate highways are included. The test simulates a 10 mile trip and averages 48 mph. The test is run from a hot start and has little idling time and no stops. The EPA GAS MILEAGE GUIDE explains that the actual test results are adjusted downward to arrive at the estimates used in the booklet and on the labels. City estimates are lowered by 10 percent and the highway estimate by 22 percent from the laboratory test results. The guide also points out that traveling at higher speeds lowers fuel economy and traveling at 65 mph instead of 55 mph lowers fuel economy over 15 percent. FACTORS THAT AFFECT FUEL ECONOMY: Axle Ratio Numerically lower axle ratios generally produce better highway fuel economy. The exception to this is if the engine is "working" exceptionally hard, (heavy vehicle loads pulling a trailer, small engine in a large vehicle ... ). In these cases a numerically higher axle may provide better fuel economy. Numerically higher axle ratios will also tend to provide more fuel economy in congested city traffic and stop and go conditions. Brakes Brake drag (even a minimal amount undetectable by coasting), can have a significant negative impact on fuel economy. Pull upward on the brake pedal to assure that the stoplight switch and cruise switch at the brake pedal are full and properly adjusted. A "click" sound when the pedal is pulled upward indicates that the switch was improperly adjusted. This causes the front brake pads to lightly rub the rotors, causing a fuel economy loss, without generating excessive heat or brake pad wear. Driving Habits Frequent short trips (less than 5 miles), especially in cooler ambient temperatures (less than 65 degrees), will necessitate fuel enrichment on start-ups, especially after "soaks" with the engine off for approximately a half hour or more. Frequent accelerator pedal movement while driving will reduce fuel economy because of fuel enrichment during the periods of acceleration. Under such driving conditions the torque converter clutch (TCC) also disengages, contributing to fuel economy losses. Prolonged idle periods reduce fuel economy especially in cold ambients when vehicle is allowed to "Warm up". Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Gauge: Customer Interest Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 4647 Fig. 7 Installing boot to caliper 5. Position dust boot in caliper counterbore and install, Fig. 7. Check the boot installation to be sure the retaining ring molded into the boot is not bent and that the boot is installed below the caliper face and evenly all around. If the boot is not fully installed, dirt and moisture may enter the bore and cause corrosion. 6. Install the brake hose in the caliper using a new copper gasket. 7. Install pads and caliper assembly. Page 395 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Control Module Engine Control Module: Locations Control Module Figure 1 LOCATION Below RH Side Of I/P. Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: All Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Page 1737 Rocker Arm Assembly: Specifications Rocker Arm Stud Torque ROCKER ARM STUD TORQUE ^ Rocker Arm Stud to Cylinder Head ................................................................................................................................................ 47 Nm (35 lb. ft.). Page 4469 Transmission Speed Sensor: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Page 7288 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 36 Symbol Identification Page 4542 Symbol Identification Page 176 Electronic Control Module Page 3747 PROM - Programmable Read Only Memory: Application and ID Footnotes 301 Thru 350 [301] Spark knock. USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [302] Hard start hot (requires installation of a rubber bumper pkg PN 25004553, and a pulsator pkg PN 25094266) or CODE 42, high idle, spark knock (G055). [303] USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [304] Hard hot restart (requires rubber bumper pkg PN 25004553, and a pulsator package PN 25094266), or CODE 42, intermittent high idle, spark knock (G055). [305] USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [306] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [307] CODES 23, 25, 33, 34, driveability and stalling (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [308] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [309] Code 23, 25, 33, 34, driveability and stalling. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [310] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [311] High emissions, exhaust odor, starting and driveability problems (G046). Requires Connector Bleed Assembly P/N 10105820 [312] FALSE CODES 43, 54, unstable idle. FOR 2.73 (GU2) AXLE USE 16120077 (SCAN I.D. = 9891). FOR 3.08 (GU4) AXLE USE 16120082 (SCAN I.D. = 9901). FOR 3.42 (GU6) AND 3.73 (GT4) AXLES USE 16120086 (SCAN I.D. = 9911). [313] Running change. FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228486 SCAN I.D. 8486, AAND 1050. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062797 SCAN I.D. 2223, AAND 2798. [314] Running change. FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228487 SCAN I.D. 8487, AANF 1052. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062801 SCAN I.D. 2233, AANF 2802. [315] Surge on acceleration and/or at road load speeds, false "Service Engine Soon" light (CODE 32), poor driveability during warm up, Detonation under load (G052). [316] Spark knock. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [317] Spark knock. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [318] Spark knock (G043). USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [319] Spark knock (G055). USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [320] CODE 42, spark knock, intermittent high idle. IF MAJOR CONDITION IS HARD HOT ENGINE RESTART, PROM ALSO REQUIRES INSTALLATION OF A RUBBER BUMPER PKG PN 25004553, AND PULSATOR PKG PN 25094266. Page 4872 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 8278 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 8197 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 3736 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [121] Stall, sags, hesitation. USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [122] USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [123] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [124] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [125] USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [126] USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [127] USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [128] USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [129] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [130] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [131] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [132] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WITH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [133] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [134] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on clutch operation, with manual transmission equipped vehicle. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [135] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [136] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [137] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [138] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [139] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). Page 423 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 7095 - An alternative in some geographic areas may be plastic media blasting such as may be provided by members of: - Dry Stripping Facilities Network 1-800-634-9185 * * We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Important Additional time or payment beyond established allowances in this bulletin will not be allowed. - The use of a razor blade on large flat surfaces is not recommended because of the potential to chip. gouge or otherwise damage the primer surface. If razor blade technique is used, the application of a "guide coat" prior to wet sanding should also be used. Note: Chemical stripping is not recommended because of negative impact to moldings, non-metal components, ELPO and environmental concerns. 4. Blow off with air to remove all dirt and sanding residue from cracks and vehicle surface. 5. Clean sanded surface with an appropriate wax and grease remover. 6. Tack wipe entire area to be primed. 7. Spray entire prepared area with a coat of anti-corrosion primer to ensure maximum adhesion and corrosion resistance. Be sure to cover any bare metal surfaces exposed during the sanding operations. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 615S/616S, BASE DE17/PR8O/DA18, PPG DP4O/DP401, or equivalent. V.O.C. materials would be: DuPont 615S/616S, BASF DE15/PA16/PRB0, PPG DCP21/DCX211 or equivalent. 8. Apply two to three medium wet coats of primer surfacer to the primed surface of the vehicle, following the manufacturer's instructions for application and film build requirements. Important Failure to apply primer surfacer will likely result in future delamination. Typical materials for this application would be: DuPont 1120S/1130S/1125S, BASF DP20/PR80/PH36, PPG K36/DT870/K201, or equivalent. V.O.C. materials would be: DuPont 210S, BASF HP400, PPG DCP21/DCX211, or equivalent. 9. After allowing adequate drying time, wet sand with 400 grit (or finer) or dry sand with 320 grit (or finer) sandpaper. 10. Repeat steps 4 through 6. 11. Apply a medium coat of corrosion resistant primer sealer (tintable base) to the entire surface to be refinished. This will provide maximum adhesion, uniform color coating and corrosion protection to areas "sanded through" during wet sanding. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 2610S/2605S, BASF DP21/DH6O/PR80, PPG DP40/DP402 or equivalent. V.O.C. materials for this application would be: DuPont 21255, PPG DPW1834 or equivalent. 12. Apply two to three medium wet coats of color (or until primer color is hidden). Follow manufacturer's instructions and recommended dry times. 13. If vehicle has basecoat/clearcoat paint, apply clearcoat. Follow manufacturer's instructions and recommended dry times. 14. After sufficient air or force dry time, unmask the vehicle. 15. Finesse/polish as required. 16. Reinstall all previously removed items. 17. Wash and prepare the vehicle for delivery. HARDWARE ITEMS REMOVAL LIST Page 5444 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 6259 Compressor Shaft Seal NOTICE: Seals should not be re-used. Always use a new specification service seal on rebuild. Be sure that the seal to be installed is not scratched or damaged in anyway. Make sure that the seal seat and seal are free of lint and dirt that could damage the seal surface or prevent sealing. Install or Connect 1. Dip the new seal seat O-ring in clean 525 viscosity refrigerant oil and assemble onto O-ring installer J 33011. 2. Insert the O-ring installer J 33011 into the compressor neck until the installer "bottoms". Lower the moveable slide of the O-ring installer to release the O-ring into the seal O-ring lower groove. (The compressor neck top groove is for the shaft seal retainer ring.) Rotate the installer to seat the O-ring and remove the installer. 3. Dip the new seal in clean 525 viscosity refrigerant oil and assemble seal to Seal Installer J 23128-A, by turning handle clockwise. The stamped steel case side of the lip seal must be engaged with knurled tangs of installer so that flared-out side of lip seal is facing and installed towards the compressor. Install seal protector J 34614, in the seal lip and place over the compressor shaft, and push the seal in place with a rotary motion or place the seal protector J 34014 over end of compressor shaft, and slide the seal onto the shaft with a rotary motion until it stops. Take care not to dislodge the O-ring. Be sure the seal makes good contact with the O-ring. Disengage the installer from the seal and remove the installer J 23128-A and the seal protector J 34614. NOTICE: Handling and care of seal protector is important. If seal protector is nicked or the bottom flared, the new seal may be damaged during installation. 4. Install the new seal retainer ring with its flat side against the Seal, using Snap-Ring Pliers J 5403. Use the sleeve from O-ring installer J 33011 to press in on the seal retainer ring so that it snaps into its groove. 5. To leak test, install compressor leak test fixture J 9625-A on rear head of compressor and connect gage charging lines and J 38100-C Refrigerant Recovery System. Pressurize suction and high-side of compressor with Refrigerant 12 vapor to drum pressure. Temporarily install (M9 x 1.25 thread on shaft) nut and. with the compressor in horizontal position, rotate the compressor shaft in normal direction of rotation several turns by hand. Leak test the seal area and correct and leak found. Recover the refrigerant. Remove shaft nut. 6. Remove any excess oil resulting from installing the new seal parts from the shaft and inside the compressor neck. 7. Install the clutch plate and hub assembly as described in minor repair procedures. 8. Reinstall compressor belt and tighten bracket. 9. Evacuate and charge the refrigerant system. Door Jamb Switch Door Switch: Locations Door Jamb Switch On A-Pillars Page 308 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 4567 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 1330 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. VIN S & W, Camshaft Dimensions Camshaft: Specifications Vin W, Camshaft Dimensions Vin W, Camshaft Dimensions Camshaft Journal Diameter 1.8682-1.8692 in Camahaft Endplay 0.001-0.009 in Camshaft Runout Maximum 0.001 in Headlight Dimmer Switch Steering Column Page 7368 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 5011 What if I input the VIN incorrectly? If an incorrect VIN is entered into the system (meaning that the system does not recognize the VIN or that the VIN has been entered incorrectly) the system will return an error message. If I am an authorized user for the KeyCode application, can I access the application from home? Yes. What if I suspect key code misuse? Your dealership should communicate the proper procedures for requesting key codes. Any suspicious activity either within the dealership or externally should be reported to Dealer Systems Support at 1-800-265-0573 or GM of Canada Key Code Inquiry Desk at 1-905-644-4892. Whose key codes can I access through the system? At this time the following Canadian vehicle codes are available through the system: Chevrolet, Cadillac, Buick, Pontiac, GMC, HUMMER (H2 and H3 only), Oldsmobile, Saturn, Saab and Isuzu (up to 2002 model year) for a maximum of 17 model years. What should I do if I enter a valid VIN and the system does not produce any key code information? Occasionally, the KeyCode Look Up application may not produce a key code for a valid VIN. This may be the result of new vehicle information not yet available. In addition, older vehicle information may have been sent to an archive status. If you do not receive a key code returned for valid VIN, you should contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. How do I access KeyCodes if the KeyCode Look-up system is down? If the KeyCode Look-up system is temporarily unavailable, you can contact the original selling dealer who may have it on file or contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the customer is dealing with an emergency lock-out situation, you need to have the customer contact Roadside assistance, OnStar if subscribed, or 911. What should I do if the KeyCode from the look-up system does not work on the vehicle? On occasion a dealer may encounter a KeyCode that will not work on the vehicle in question. In cases where the KeyCode won't work you will need to verify with the manufacturer of the cutting equipment that the key has been cut correctly. If the key has been cut correctly you may be able to verify the proper KeyCode was given through the original selling dealer. When unable to verify the KeyCode through the original selling dealer contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the key has been cut correctly and the code given does not work, the lock cylinder may have been changed. In these situations following the proper SI document for recoding a key or replacing the lock cylinder may be necessary. How long do I have to keep KeyCode Records? Dealership KeyCode documentation must be retained for two years. Can I get a KeyCode changed in the Look-Up system? Yes, KeyCodes can be changed in the Look-Up system if a lock cylinder has been changed. Contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. What information do I need before I can provide a driver of a company fleet vehicle Keys or KeyCode information? The dealership should have a copy of the individual's driver's license, proof of employment and registration. If there is any question as to the customer's employment by the fleet company, the dealer should attempt to contact the fleet company for verification. If there is not enough information to determine ownership and employment, this information should not be provided. How do I document a request from an Independent Repair facility for a KeyCode or Key? The independent must provide a copy of their driver's license, proof of employment and signed copy of the repair order for that repair facility. The repair order must include customer's name, address, VIN, city, province and license plate number. Copies of this information must be included in your dealer KeyCode file. Page 6682 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 6761 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 889 Disclaimer Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: All Technical Service Bulletins Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Bendix Brake Boosters Vacuum Brake Booster: Testing and Inspection Bendix Brake Boosters Accumulator Leak-Down, System Does Not Hold Charge 1. Contamination in steering hydro-boost system. 2. Internal leakage in accumulator system. Grabby Brakes or Booster Chatters/Pedal Vibrates 1. Faulty spool action caused by contamination in system. 2. Power steering pump belts slip. 3. Low fluid level in power steering pump. 4. Faulty spool operation caused by contamination in system. Slow Brake Pedal Return 1. Excessive seal friction in booster. 2. Faulty spool action. 3. Restriction in return line from booster to pump reservoir. 4. Damaged input rod end. Page 8332 B. Locate the two grille to fender fasteners at the bottom of the grille (one on each side). These can be either Christmas Tree style retainers or bolts: a. If the grille has Christmas Tree style retainers, it is NOT necessary to remove them. b. If the grille has two grille to fender bolts, remove them. C. Disconnect the side marker lamp connectors. 2. From the back side of the grille, apply clear G.M.S. sealer (P/N 1052915 or equivalent), along the entire leading edge of the side marker lamp(s) (Figure 1, View A). 3. Reinstall the grille. A. If the grille is equipped with Christmas Tree style retainers, one on each side of ghlle, snap the grille in place prior to torquing the remaining fasteners. If required, replace the Christmas Tree style retainers (P/N 15672328). B. If the grille is equipped with two grille to fender bolts located at the bottom of the grille, one on each side, instead of Christmas Tree style retainers, reinstall the bolts and torque them to 1.6 - 2.2 N-m. (13-18 lbs.in.). C. Torque the remaining eight fasteners located across the top of the grille and within the egg crate area to 1.2 - 1.6 N-m. (10-13 lbs.in.). SERVICE PARTS INFORMATION Part Number Description Qty/Veh 1052915 G.M.S. Sealer-Type A As Required 15672328 Retainer-Radiator Grille As Required Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B1308 Use applicable labor time guide for labor hours. Page 1237 Brake Bleeding: Technical Service Bulletins Brakes - Revised 4WAL System Bleeding Procedure BULLETIN NUMBER: 93-5E-74 SECTION: 5E Antilock Brakes NUMBER: 3 CORPORATE REFERENCE NUMBER: 365003 DATE: May 1993 SUBJECT: REVISED 4WAL BRAKE SYSTEM BLEEDING PROCEDURE (INFORMATIONAL) MODELS: 1990-93 MIL, S/T AND 1992-93 C/K AND 1993 G MODELS WITH 4WAL THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 91-5E-23, CORPORATE NUMBER 065001R, DATED SEPTEMBER 1990 TO UPDATE THE BLEED PROCEDURE AND TO ADD MODELS SINCE EQUIPPED WITH 4WAL BRAKE SYSTEMS. ALL COPIES OF 91-5E-23 SHOULD BE DISCARDED. THIS BULLETIN ALSO UPDATES INFORMATION IN 1993 MIL SERVICE MANUAL X9330, 1993 S/T SERVICE MANUAL X9329, 1993 C/K SERVICE MANUAL X9331, 1993 G SERVICE MANUAL X9357, AND STG RWAL/4WAL 1988-1991 APPLICATIONS MANUAL 15005.05 (VERSIONS 2 TO 5). PLEASE PLACE A COPY OF THIS BULLETIN IN EACH MANUAL. THIS BULLETIN IS EQUIVALENT TO SERVICE MANUAL UPDATE (CORP. NO. 263003). This 4WAL brake system bleed procedure is the most efficient bleed procedure to date. The 4WAL Brake Pressure Modulator Valve (BPMV), formerly called Electro Hydraulic Control Unit (EHCU), should be bled after replacement or if air is suspected to be trapped inside the unit. There are two conventional methods to use when bleeding the 4WAL BPMV: (1.) Pressure Bleeding or (2.) Manual Bleeding. Important There are two internal bleed screws (brass colored), one on each side of the BPMV, that open internal channels. Open the internal bleed screws 1/4 to 1/2 turn before bleeding (Figure 2). New 4WAL BPMV's are shipped with the internal bleed screws open, so first close the internal bleed screws until snug, then open 1/4 to 1/2 turn. Note: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid Page 7638 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 8341 Forward Lights Harness, RH Side Service and Repair Window Handle: Service and Repair Front Door Window Regulator Handle TOOL REQUIRED: J-9886-O1, Door Handle Remover. REMOVE OR DISCONNECT 1. Window regulator handle. ^ Insert J-9886-O1 between the handle and the bearing plate. ^ Align the tool parallel with the door handle, and push to disengage the clip. ^ Pull the handle from the door. 2. Bearing plate. INSTALL OR CONNECT 1. Bearing plate. 2. Window regulator handle. ^ Place the window in the raised position. ^ Put the clip onto the handle, ^ Insert the handle onto the door so the handle is pointing towards the front of the door. ^ Push on the handle until the clip engages the window regulator shaft. Page 3883 Page 4318 for models with 8-1/2 or 8-7/8 inch ring gear, Figs. 16 and 17, or suitable equivalents. On models with 8-7/8 inch ring gear, substitute cloverleaf gauge plate J-21777-36 for plate J-21777-29. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate onto preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque are required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. e. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. f. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold drive shaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 9 1/2 Inch Ring Gear Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Page 8268 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 2956 Manifold Pressure/Vacuum Sensor: Testing and Inspection Manifold Absolute Pressure Output Check Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures the changes in the intake manifold pressure which result from engine load (intake manifold vacuum) and rpm changes; and converts these into a voltage output. The control module sends a 5 volt reference voltage to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the control module knows the manifold pressure. At lower pressure output voltage will be about 1 to 2 volts. While at higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts.The MAP sensor is also used, under certain conditions, to measure barometric pressure, Page 4556 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Initial Inspection and Diagnostic Overview Control Assembly Operating Chart Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Page 1507 sure the retainer cup is tree from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. Important: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Except for the N9O 4X4 wheel used on T trucks, all light truck aluminum wheels will accept either "AW" series or "MO" series clip-on coated weights on both the inside and outside rim flanges. The N9O T truck wheel will accept "AW" series weights on the inside rim flange only. The outside rim flange is not designed to accept a clip-on weight. If such a weight installation is attempted, a poor fit will result, and the weight may fall off and/or cause cosmetic damage to the rim flange. This wheel can be 1) static balanced by clipping all the weight on the inside rim flange (as is done in the assembly plant), or 2) dynamic balanced by clipping a weight on the inside flange and using an adhesive weight near the outside flange. The charts show "AW" and "MC" balance weight usage. These original equipment coated weights are available at competitive prices through the GM Dealer Equipment program. Fuel Supply/Return/or Emission Pipe Service Fuel Return Line: Service and Repair Fuel Supply/Return/or Emission Pipe Service NOTES When replacing fuel feed and return pipes, always replace them with original equipment or parts that meet GM specifications for those parts. The replacement pipe must have the same type fittings as the original pipes to ensure the integrity of the connection. Do NOT use copper or aluminum tubing to replace steel tubing. Only tubing meeting the 124M specification or its equivalent is capable of meeting all pressure and vibration characteristics necessary to ensure the durability standard required. Many of the feed and return pipes use screw couplings with O-rings. Any time these fittings are loosened to service or to replace components, ensure that: A back-up wrench is used to loosen and tighten fittings. - Check all O-rings at these locations (if applicable) for cuts or any damage and replace as necessary. - Use correct torque when tightening these fittings. - Inspect all pipes for kinks, leaks or dents. - Pipes must be properly secured to the frame to prevent chafing. A minimum of 6 mm (1/4 inch) clearance must be maintained around a pipe to prevent contact or chafing. - Fuel feed and return pipes are secured to the underbody with clamps and screw assemblies. - Follow the same routing as the original pipe. - Fuel pipes must not contact the fuel tank or underbody at any point. FUEL AND VAPOR PIPE REPAIR When it is impractical to replace an entire fuel line to repair localized damage, use the following procedure: When rubber hose is used to replace pipe, use only reinforced fuel-resistant hose which is identified with the word "Fluoroelastomer" on the hose. The inside diameter of the hose must match the outside pipe diameter. - Do NOT use rubber hose within 100 mm (4 inches) of any part of the exhaust system, or within 254 mm (10 inches) of the catalytic converter. - In repairable areas, cut a piece of hose 100 mm (4 inches) longer than the portion of line removed. If more than a 6 inch length of pipe is removed, use a combination of steel pipe and hose so that hose lengths will not be more than 254 mm (10 inches). - Follow the same routing as the original pipe. - Cut the ends of the pipe, remaining on the car, square with a tubing cutter. Using the first step of a double flaring tool, form a bead on the end of each pipe section. If the pipe is too corroded to withstand the beading operation without damage, the pipe should be replaced. If a new section of pipe is used, form a bead on both ends of it also. - Use a screw type hose clamp NO. #2494772, or equivalent. Slide the clamps onto the pipe and push hoses 51 mm (2 inches) onto each portion of the fuel pipe. Tighten the clamps on each side of the repair. - Pipes must be properly secured to the frame to prevent chafing. Page 6144 Clutch Plate And Hub Assembly Removal 3. Thread the Clutch Plate and Hub Assembly Remover J 33013-B into the hub. Hold the body of the remover with a wrench and turn the center screw into the remover body to remove the clutch plate and hub assembly. 4. Remove the shaft key and retain for reassembly. Install or Connect Shaft Key, Clutch Plate/Hub Assembly 1. Install the shaft key into the hub key groove. Allow the key to project approximately 3.2 mm (1/8") out of the keyway. The shaft key is curved slightly to provide an interference fit in the hub key groove. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the clutch plate and hub assembly. 3. Align the shaft key with the shaft keyway and place the clutch plate and the hub assembly onto the compressor shaft. NOTICE: Do not drive or pound on the clutch hub or shaft. Internal damage to compressor may result. Locations LH I/P And Four-Wheel Drive Indicator Page 8749 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Capacity Specifications Clutch Fluid: Capacity Specifications Fill the clutch master cylinder to the "Full" or "MAX" mark on the reservoir. Do not overfill. Caution: Should accidental spillage occur, rinse the area thoroughly with water. Pay special attention to any electrical wires, parts, harnesses, rubber or painted surfaces. Page 6455 Blower Motor Relay: Service and Repair Evaporator And Blower Assembly Component View REMOVE OR DISCONNECT 1. Electrical connectors, as necessary. 2. Screws (34). 3. Relay (42). INSTALL OR CONNECT 1. Relay (42). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 2. Screws (34). 3. Electrical connectors, as necessary. - Check circuit operation. Page 8221 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 4598 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 6150 Clutch Coil Assembly Removal 2. Install J 33023-A puller pilot on front head of compressor. Also install J 8433-1 puller crossbar with J 33025 puller legs as shown in the illustration. 3. Tighten J 8433-3 forcing screw against the puller pilot to remove the clutch coil. Install or Connect 1. lace the clutch coil assembly on the front head with the terminals positioned at the "marked" location. 2. Place the J 33024 clutch coil installer over the internal opening of the clutch coil housing and align installer with the compressor front head. Installing Clutch Coil Assembly Page 3732 PROM - Programmable Read Only Memory: Application and ID Footnotes 51 Thru 100 [51] Must be ordered with service kit P/N 10115773. [52] With this PROM installed, use 1987-88 2.8L speed density engine driveability and emissions manual. [53] PROM update eliminates MAF sensor, replacing it with a speed density system. With a 1990 or earlier primary cartridge, I.D. vehicle on scanner as a 1989 model (VIN = K-1-W). [54] For 2WD use 16120099 (SCAN I.D. = 9941). For 4WD use 16120109 (SCAN I.D. = 9901). [55] For 2.73 (GU2) Axle use 16120077 (SCAN I.D. = 9891). For 3.08 (GU4) Axle use 16120082 (SCAN I.D. = 9901). For 3.42 (GU6) and 3.73 (GT4) Axles use 16120086 (SCAN I.D. = 9911). [56] For 2WD use 16120042 (SCAN I.D. = 9991). For 4WD use 16120129 (SCAN I.D. = 0011). [57] Needs accelerator pump check ball spring P/N 17069583. [58] For false Code 44 on long coast down, use retrofit service PROM 01228486 AAND 1050. For regular service replacement, use PROM 16062797 AAND 2798. [59] For false Code 44 on long coast down, use retrofit service PROM 01228487 AANF 1052. For regular service replacement, use PROM 16062801 AANF 2802. [60] USE 16143545 (SCAN I.D. = 3461) For hot hard restart (Requires Fuel Pump P/N 25115764, Fuel Sender P/N 25093744). Use 16143465 (SCAN I.D. = 3471) for Code 42, Spark Knock, High Idle. [61] With this PROM installed, use 1987-88 2.8L speed density engine driveability and emissions manual. [62] For use with model C1 Trucks - Use 16121162 (SCAN I.D. = 3511). For use with model C2, K, K2, AND K1000 Trucks - use 16121166 (SCAN I.D. = 3521). [63] Also requires installation of new EGR valve package P/N 17112238 (Contains EGR valve P/N 17090078 and a gasket). [64] Use 16181863 (SCAN I.D. = 0844) for cold start stall. Use 16181859 (SCAN I.D. = 0834) only if required to solve both cold start stall and chuggle. [65] Use 16181871 (SCAN I.D. = 0864) for cold start stall. Use 16181867 (SCAN I.D. = 0854) only if required to solve both cold start stall and chuggle. [66] Use 16165848 (SCAN I.D. = 5614) for cold start stall. Use 16165843 (SCAN I.D. = 5624) only if required to solve both cold start stall and chuggle. [67] Do not rely on the scanner ID to determine which PROM is in a vehicle. Look at the BCC on the PROM to be sure. Do not confuse with some 1991 models with a 2.84 axle ratio and a Federal emissions pkg which used scanner ID 5644 but had a BCC of AWJD. [68] This PROM may have a negative impact on fuel economy. [69] Cannot be used on vehicles that do not have digital EGR valves. [70] Use 16165839 (SCAN I.D. = 5634) for cold start stall. Use 16165829 (SCAN I.D. = 5644) only if required to solve both cold start stall and chuggle. [71] Use 16181883 (SCAN I.D. = 0894) for cold start stall. Use 16181875 (SCAN I.D. = 0874) only if required to solve both cold start stall and chuggle. [72] Use 16181887 (SCAN I.D. = 0904) for cold start stall. Use 16181879 (SCAN I.D. = 0884) only if required to solve both cold start stall and chuggle. [73] This PROM may have a negative impact on fuel economy. [74] PROM can only be used with ECM P/N 16144288. [75] Make certain the vehicle has been updated with previously attempted service fixes as follows: EGR valve P/N 17090156 (stamped on valve) 17112373 (GMSPO kit), PCV valve P/N 25098542, ESC module P/N 16175099 (BCC=BARC). Page 94 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Capacity Specifications Fluid - Differential: Capacity Specifications Rear Axle Oil Pints 3.9 pt (US) Front Drive Axle 2.6 pt (US) Page 7226 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 2609 Throttle Position Sensor: Adjustments N/A: TPS is not adjustable on this engine. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Page 8196 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 6116 3. Electrical connector (78) to resistor (80). - Check circuit operation. Page 1087 1 Gallon 12346144 55 Gallon 12346145 In Canada 1 Liter 10952622 4 Liter 10952623 200 Liter 10952624 The 1995 Automatic Transmission/Transaxle fluid change intervals are the following: (1994 and prior should use the schedules as written in the Owner's Manual.) If the vehicle is mainly driven under one or more of these conditions: In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. Uses such as found in taxi, police car or delivery service. Change the fluid and filter every 50,000 miles (63,000 km). If the vehicle is not used mainly under any of these conditions, the fluid and filter do not require periodic changing for vehicles under 8,600 GVWR. Vehicles over 8,600 GVWR change the fluid and filter every 50,000 miles (83,000 km) regardless of driving conditions. Page 430 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 7434 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 5515 For vehicles repaired under warranty, use the table. Disclaimer Page 5878 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Page 5059 Starter Solenoid: Locations Battery ................................................................................................................................................. .......................... R/H front of engine compartment Battery Junction Block ........................................................................................................................................ Engine Compartment, on center of cowl Generator ........................................................................................ ........................................................................................................... Front of Engine Ignition Switch .............................................................................................................................................................. ......... R/H side of steering column Starter Motor ................................................................................ .............................................................................................. Lower RH side of engine C100 ............. .............................................................................................................................................................. ............................. L/H side of cowl G100 ........................................................................................... .......................................................................................................... R/H side of engine G101 .......... .............................................................................................................................................................. ........................ Above R/H headlamp S100 ........................................................................................ ................................................................................................................ Behind generator S101 ....... .............................................................................................................................................................. ................................... Behind generator S200 .................................................................................... .............................................................................. Behind L/H side of I/P, above fuse block S209 .... .............................................................................................................................................................. ... Behind L/H side of I/P, near I/P cluster Page 4261 Differential Axle Housing: Service and Repair Chevrolet Salisbury Semi-Floating Axle Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and place stand jacks under frame side rails. 2. Remove rear wheels and drums. 3. Support rear axle assembly with a suitable jack so that tension is relieved in springs and tie rod, if equipped. 4. Disconnect tie rod at axle housing bracket, if equipped. 5. Remove trunnion bearing U-bolts from rear yoke, split universal joint, position propeller shaft to one side and tie it to frame side rail. 6. Remove axle U-bolt nuts and allow shock absorbers to hang freely so that they do not interfere with axle. On K and V Series trucks, remove spacer from axle housing. 7. Disconnect hydraulic brake hose at connector on axle housing. 8. Remove brake drum and disconnect parking brake cable at lever and at flange plate. 9. Lower axle and remove from vehicle. 10. Reverse procedure to install axle assembly. Tires (Front) - Irregular Wear Tires: Customer Interest Tires (Front) - Irregular Wear Number: 91-26-3E Section: 3E Date: June 1990 Corp. Bulletin No: 053501 Subject: FRONT TIRE WEAR Model and Year: 1982-91 LIGHT DUTY TRUCKS (REAR WHEEL DRIVE) THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-12-3E. THE KILOMETERS HAVE BEEN TRANSLATED INTO MILES. ALL COPIES OF 91-12-3E SHOULD BE DISCARDED. Rear wheel drive trucks, equipped with All Season and/or On-Off road tires may exhibit irregular wear of; the front tires. Small amounts of irregular wear is considered normal and is not necessarily a result of incorrect alignment. Incorrect alignment (especially toe) may result in premature wear of the front tires, however agressive cornering may also have a similar effect. Drive axle tires are much less prone to irregular wear, therefore they should not be considered for comparison of wear to non-drive axle tires. The rate of irregular wear is also dependent upon the depth of tread. New tires are more prone to irregular wear, so it is essential that tires are rotated at the proper intervals to normalize the wear. Page 7458 Clutch Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 6161 5. With the compressor mounted to the J 25008-A Holding Fixture, position the Rotor and Bearing Assembly on the front head (Fig. 22). Using Rotor and Bearing Installer J 9481-A and Universal Handle J 29886 drive the rotor and bearing assembly onto the front head. With the Installer assembled to the Handle as shown in Figure 22, force will be applied to the inner race of the bearing when installing the assembly onto the front head of the compressor. 6. Install rotor and bearing assembly retainer ring, using Snap Ring Pliers J 6083 (Fig. 9). 7. Reinstall clutch plate and hub assembly as described previously. Clutch Coil and/or Pulley Rim V-Groove Drive - 4 Pole Clutch Remove or Disconnect Perform Steps 1 through 4 of COMPRESSOR CLUTCH ROTOR AND/OR BEARING removal procedure but do not loosen or remove the pulley rim mounting screws until the Clutch Rotor, Coil and Pulley Rim assembly have been removed from the Front Head. Be careful not to drop the Puller Guide J 25031 when removing the assembly. 2. Remove the pulley rim mounting screws and discard. 3. Slide the pulley rim off the Rotor and Hub assembly The Pulley Rim and the Clutch Coil (Fig. 24) are replaceable at this point. Install or Connect Page 1180 Omega Refrigerant Reclamation 5263 North Fourth St. Irwindale, CA 91706 310-698-0991, FAX 310-696-1908 Refrigerant Management Svcs of Georgia 216 F. Atlanta Hwy. Cumming, GA 30130 Ph/FAX 800-347-5872 Refrigerant Reclaim Inc. 122 Old Stage Coach Rd. Dumfries, VA 22026 800-238-5902, FAX 703-441-0393 Gartech Refrigerant Reclamation Ctr. 2002 Platinum Garland, TX 75042 214-272-4070, FAX 214-272-8548 National Refrigerants, Inc. 11401 Roosevelt Blvd. Philadelphia, PA 19154 215-698-6620, FAX 215-602-8205 CFC Reclamation 1321 Swift North Kansas City, MO 64116 816-471-2511 Full Cycle-Global 550 James Street Lakewood, NJ 08701 908-370-3400, FAX - 908-370-3088 Refrigerant Reclaim Svcs, Inc. dba Full Cycle-Global 121 S. Norwood Drive Ft. Worth, TX 76053-7807 817-282-0022, FAX - 800-831-6182 Full Cycle-Global 2055 Silber, Ste. 109 Houston, TX 77055 713-681-7370, FAX - 713-681-9947 Full Cycle-Global 343 South Airline Hwy. Gonzales, LA 70737 504-644-5303, FAX - 504-644-1809 Full Cycle-Global 2966 Wireton Blue Island, IL 60406 708-388-8551, FAX - 708-388-8550 Inline Fuse, Trailer Towing Harness Fuse: Locations Inline Fuse, Trailer Towing Harness Center Of Dash Panel, In Engine Compartment Page 6261 Removing The Felt Ring Metal Retainer - Insert the points J 4245 into the holes in the retainer and lift out). 3. Shaft seal seat snap ring. Removing The Shaft Seal Seat 4. Shaft seal seat (23) with J 38479. 5. Seal assembly Page 7571 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Campaign - Interior Front Door Handles Technical Service Bulletin # 06027A Date: 070523 Campaign - Interior Front Door Handles Bulletin No.: 06027A Date: May 23, 2007 SPECIAL COVERAGE Subject: 06027A - SPECIAL COVERAGE ADJUSTMENT - CLASS ACTION SETTLEMENT - INTERIOR DOOR HANDLE SPRING BREAKAGE Models: 1982-1994 CHEVROLET S/T PICKUP AND UTILITY 1982-1994 GMC S/T PICKUP AND UTILITY, JIMMY 1991-1994 OLDSMOBILE BRAVADA INVOLVED IN SOUTH CAROLINA CLASS ACTION SETTLEMENT Supercede: The expiration date for this special coverage has been extended to December 31, 2007. The mailing of letters to customers was delayed. Letters will be mailed to customers on May 30, 2007. Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Condition Some customers of 1982-1994 Chevrolet S/T pickup and utility vehicles; 1982-1994 GMC S/T pickup and utility vehicles; and 1991-1994 Oldsmobile Bravada vehicles are entitled to the benefits of a class action settlement. The benefits are listed below and customers will be provided with a letter to present to dealers that details the remedy that they chose. Special Coverage Adjustment This special coverage covers the conditions described below until December 31, 2007. Customers may have any combination of the benefits listed below. Please see the customer's letter to determine the appropriate remedy. Reimbursement - Customers who have replaced an interior front door handle assembly have already submitted a request for reimbursement. GM is handling the reimbursements. There is no action required from the dealer. Replacement of broken interior front door handle assembly(s) - Some customers have chosen to receive a replacement interior front door handle assembly(s). Dealers are to provide the customer with the assembly(s) at no charge. The customer is to self-install or pay the dealer for the installation of the assembly(s). Application of lithium grease - Customers who have the original front door handle assembly(s) in which the spring is not broken, are entitled to have the spring(s) greased. Dealers are to apply lithium grease to the unbroken spring(s) of the original front door handle assembly(s) at no charge. Vehicles Involved Customers involved will present the dealer their vehicle with a letter that authorizes the repair. If the customer requests a new interior front door handle, dealer must verify it replaces a broken interior front door handle assembly. Page 7177 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 649 Oxygen Sensor: Specifications Sensor Voltage Range Sensor Voltage Range Sensor Voltage (Closed Loop) 0.1 to 1.0 V Page 8673 Front Door Trim Panel Page 7274 Figure 7 Figure 8 Figure 9 Figure 10 Page 8618 Rear Window Release & Defogger Components. Below Cigar Lighter Applicable to: 4Door Blazer & Jimmy Page 976 Disclaimer Page 7523 Figure 7 Figure 8 Figure 9 Figure 10 Page 3345 Parts Information Parts are currently available from GMSPO. Page 745 Symbol Identification Page 3193 Disclaimer Page 6028 A. Obtain a straight edge approximately 8-9 inches long and, while holding it in two hands, as shown in the attached illustration, place it on the inboard mounting surface of the wheel and try to rock it up and down. B. Repeat the above procedure on three or four different positions on the wheel inboard mounting surface. C. The outer ring of the mounting surface is normally raised above everything inside it. If a wheel mounting surface has been bent on a tire changer, it will be raised above the outer ring and the straight edge will rock on this "raised" portion. D. If a bent wheel is found, it must be replaced. EGR Filter Replacement EGR Filter: Service and Repair EGR Filter Replacement EVRV Filter Replacment Removal and Installation - Grasp and pull the filter OFF with a rocking motion. - Push the new filter on making sure that the cut-out for the wires is properly aligned. Page 5193 Fuse Block Details Page 7775 TCC Solenoid Rear Of Engine Engine - Drive Belt Misalignment Diagnostics Drive Belt: Technical Service Bulletins Engine - Drive Belt Misalignment Diagnostics INFORMATION Bulletin No.: 08-06-01-008A Date: July 27, 2009 Subject: Diagnosing Accessory Drive Belt / Serpentine Belt Noise and Availability and Use of Kent-Moore EN-49228 Laser Alignment Tool - Drive Belt Models: 2010 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add a model year and update the Tool Information. Please discard Corporate Bulletin Number 08-06-01-008 (Section 06 - Engine). Background Several aftermarket companies offer laser alignment tools for accessory drive systems that can be very helpful in eliminating drive belt noise as a result of misaligned pulleys. Typically pricing ranges from $160 - $200. EN-49228 Laser Alignment Tool - Drive Belt The GM Tool program has now made available a competitive, simple to use and time-saving laser tool to assist in achieving precise alignment of the drive belt pulleys. This optional tool removes the guesswork from proper pulley alignment and may serve to reduce comebacks from: - Drive Belt Noise - Accelerated Drive Belt Wear - Drive Belt Slippage Instructions The instructions below are specific only to the truck Gen IV V-8 family of engines. These instructions are only for illustrative purposes to show how the tool may be used. Universal instructions are included in the box with the Laser Alignment Tool - Drive Belt. Caution - Do not look directly into the beam projected from the laser. - Use caution when shining the laser on highly polished or reflective surfaces. Laser safety glasses help reduce laser beam glare in many circumstances. - Always use laser safety glasses when using the laser. Laser safety glasses are not designed to protect eyes from direct laser exposure. 1. Observe and mark the serpentine belt orientation. Page 7366 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 6206 Installing The Coil Housing 2. Clutch coil (8) to the front head (16). - Align the coil and housing assembly on the compressor front head (16) so that the electrical terminals line up the marks scribed on the compressor. - Align the coil locator projections on the coil housing with the holes in the front head (16). 3. Coil and housing retainer ring (7) with J 6435. Clean Remove any excess adhesive. 4. Pulley and bearing assembly (5 and 6). 5. Clutch plate and hub assembly (2). Page 7556 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 8520 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 4612 Hydraulic Assembly: Service and Repair Rear Wheel Anti-Lock Brake System Fig. 46 ECU & Control Valve Assembly Installation 1. Disconnect brake lines from control valve, the plug lines and open fittings. 2. Remove bolts (25) securing control valve, Fig. 46, and support valve assembly. Do not allow valve assembly to hang from wiring. 3. Disconnect electrical connectors and remove control valve assembly. 4. Reverse procedure to install, then bleed brakes as needed. Locations Engine Wiring, LH Side A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 2778 ECM QDR Check Procedure Page 3735 PROM - Programmable Read Only Memory: Application and ID Footnotes 101 Thru 150 [101] Driveability correction for heavy chuggle. REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [102] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [103] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [104] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [105] Surge. RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROM. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE. [106] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [107] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [108] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [109] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [110] Surge. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [111] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [112] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [113] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [114] Surge, flatness or tip-in hesitation. RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROMS. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [115] FOR USE WITH P215/65 TIRES - USE 01228290 (SCAN I.D. = 8290). FOR USE WITH P235/60, P245/50 TIRES - USE 01228291 (SCAN I.D. = 8291). [116] FOR USE WITH P215/65 TIRES - USE 01228290 (SCAN I.D. = 8290). FOR USE WITH P235/60, P245/50 TIRES - USE 01228291 (SCAN I.D. = 8291). [117] Spark knock only. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [118] Spark knock only. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [119] Spark knock. USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [120] Detonation. USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 Page 2869 Oxygen Sensor: Description and Operation Exhaust Oxygen Sensor (02) PURPOSE The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315°C (600°F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Oxygen Sensor Output Voltage vs. Air/Fuel Ratio The difference in oxygen concentration in the narrow range of optimum air/fuel ratio causes a large voltage change that is easily measured. OPERATION A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. Page 1077 Coolant: Technical Service Bulletins Cooling System - Reconstituted Anti-Freeze Information Number: 90-49-6B Section: 6B Date: August 1989 Corporate Bulletin No.: 930107 Subject: RECONSTITUTED ANTI-FREEZE Model and Year: ALL MODELS, ALL MODEL YEARS TO: ALL CHEVROLET DEALERS This bulletin provides information on "reconstituted anti-freeze". It has been brought to our attention that a number of manufacturers claim to have the capability of reconstituting engine coolant on site. At this time, General Motors does not endorse this practice or any equipment. Anti-freeze recycling is a very complex issue. In use as an engine coolant, ethylene glycol becomes oxidized producing a very degraded and deteriorated substance. Contamination by other automotive fluids during draining, handling and storage is also a major detriment to the reclaiming process. There is no additive we are aware of that can be merely put into used coolant that will restore it to an acceptable state. Typically, a multi-million dollar facility, utilizing sophisticated technology with distillation capabilities along with appropriate quality control would be required to adequately process used coolant to bring it to GM specifications. Disposal of all chemical products should be done in accordance with all applicable federal, state and local laws and regulations. Review engine coolant substitutes Dealer Service Bulletin No. 89-57-6B, dated January 1989. Page 3172 Accelerator Controls: Locations Accelerator Pedal Assembly PEDAL ASSEMBLY Accelerator Cable CMFI LINKAGE Service and Repair Drive Belt Tensioner: Service and Repair Fig. 20 Serpentine Drive Belt Routing 1. Remove belt tensioner pulley retaining bolt. 2. Remove belt tensioner pulley. then the belt. 3. Reverse procedure to install, refer to Fig. 20 for belt routing. Service and Repair Crankcase Filter: Service and Repair Inspection The crankcase ventilation system should be checked every 30,000 miles and also during regular engine tune-ups. If the crankcase ventilation system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the crankcase ventilation valve or air cleaner is replaced. When a periodic inspection indicates the crankcase ventilation is not functioning properly, it should be serviced by replacement only. Front Caster and Camber Adjustment Alignment: Service and Repair Front Caster and Camber Adjustment Fig. 1 Caster & Camber Adjustment. 4 X 2 Models Before checking or adjusting caster and camber angles, jounce vehicle at least 3 times to prevent false geometric readings. 4 X 2 MODELS Caster and camber adjustments are made by shims inserted between upper control arm shaft and frame bracket, Fig. 1. Add, subtract, or transfer shims to change readings as noted below. To adjust caster and/or camber, loosen upper control arm shaft to frame nuts, then add or subtract shims as necessary and torque upper control arm shaft to frame nuts to specification. Caster Transfer shims from front to rear, or rear to front. The transfer of one shim from rear to front bolt will decrease positive caster. Camber Change shims at both front and rear of shaft. Adding an equal amount of shims at both front and rear locations will decrease positive camber. After adjustment, the shim pack should have at least two threads of bolt exposed beyond the nut. The difference between front and rear shim packs must not exceed 0.40 inches. 4 X 4 MODELS Caster and camber adjustments are made by cam mounted upper control arm attaching bolts. To adjust caster and/or camber, loosen upper control arm to frame attaching bolt nut, then rotate cam by turning bolt head. Caster To increase positive caster, move front cam lobe inward and rear cam lobe outward. Camber To increase positive camber, move both front and rear cam lobes inward. When proper alignment settings are established, torque upper control arm to frame attaching bolt nut to specification. Page 4247 Differential Clutch: Service and Repair 9 1/2 Inch Ring Gear Cam Gear Clutch Fig. 6 Cam Gear Thrust Ring Removal. Eaton Locking Differential 1. Measure and record overall length of cam gear assembly from front face of gear to back side of thrust ring, including shim. 2. With gear hub facing up, compress disc pack and insert jaws of suitable split ring bearing puller between thrust ring and top eared disc with bevel side of puller facing thrust ring, Fig. 6. 3. Support bearing remover in press and press cam gear from thrust ring using 1-3/4 inch diameter spacer. Keep all component in order as cam gear is removed. 4. Remove disc pack and cam plate from gear, clean and inspect components, and replace any that are damaged or excessively worn. Do not replace thrust ring and/or cam gear unless necessary. If ring or gear is excessively worn or scored, inspect bore in case. If case bore is scored, entire assembly must be replaced. If cam gear or thrust ring are replaced, shim thickness must be selected to provide original assembly dimension and proper differential pinion backlash. 5. Position cam gear on flat surface with hub end up and install cam plate with cam form down to mate with form on gear. Fig. 5 Exploded View Of Eaton Locking Differential 6. Assemble two eared discs, one splined disc and wave spring onto cam plate as shown in Fig. 5. If components are reused, they must be installed in original position. 7. Alternately assemble three splined and four eared discs on cam gear hub, as shown in Fig. 5. 8. Mount cam gear assembly in press and position thrust ring over gear hub. 9. Compress disc pack to prevent splined disc from being trapped, then press thrust ring onto gear until seated against shoulder of gear. 10. Inspect assembly to ensure that discs are properly assembled and that first splined disc (large spline) is properly located on cam plate. Page 1343 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 5255 Relay Box: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 3949 Fluid Pump: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pump Assembly To Case .................................................................................................................... ............................................................................... 18 Pump Cover To Body ..................................... .............................................................................................................................................................. ..... 18 Solenoid Assembly To Pump ................................................................................................... ............................................................................................ 8 Page 1575 A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 3812 (1994-1997). Design 2 1-2 accumulator assemblies with a composite (plastic) piston and an ovate wire outer spring, started May 11, 1998 (Julian Date 131), use service package P/N 24214343 (1998-1999). Notice: Failure to follow the above instructions may result in transmission distress. Parts Information Parts are currently available from GMSPO. Page 6121 - Install the blower switch knob. 2. Control cables (60 and 65). 3. Electrical connection (82). 4. Control assembly (63). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 5. Screws (64). - Check circuit operation. Page 4863 Antilock Brake Module: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 7435 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Body & Frame - Misalignment of Pickup Box to Cab Truck Bed: All Technical Service Bulletins Body & Frame - Misalignment of Pickup Box to Cab Number: 93-91-10 Section: 10 Date: JAN. 1993 Corporate Bulletin No.: 261514 ASE No.: B1 Subject: MISALIGNMENT OF PICKUP BOX TO CAB Model and Year: 1982-93 S/T TRUCKS Some owners of 1982-1993 S/T pickups may comment about misalignment of the pickup box to the cab. CAUSE: Misalignment may occur as a result of the frame mounting hole not allowing side to side adjustment. CORRECTION: To correct, it is necessary to enlarge the left front hole on the frame at the front of the pickup box and realign the box to the cab. SERVICE PROCEDURE: 1. Loosen all of the pickup box to frame bracket mounting bolts. Remove only the left corner bolt. 2. Raise and support the front left corner of the box approximately one inch (1"). 3. Drill, from the bottom up, the left front hole in the frame mounting bracket enlarging the hole to approximately 17 mm (11/16") ID. 4. Lower the box and loosely reinstall the left front corner mounting bolt. 5. Align the box to the cab body. Torque all the box to frame bracket mounting bolts 40-54 N-m (30-40 lbs.ft.). WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B5300 Use applicable labor time guide for labor hours. Page 7601 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: All Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Specifications Shift Solenoid: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Page 1214 89-93 - Suction hose - 96068490 89-93 - Discharge hose - 96068489 Suction hose: 85-86 - 91172086 85-86 Dealer installed: 91172087 87-88 - 91172088 89-93 - w/turbo - 96069121 - w/o turbo - 91172089 Discharge hose: 85-86 - 91172082 85-86 Dealer installed: 91172083 87-88 - 91172084 89-93 - 96069024 1989-93 Tracker 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the Retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 550 grams (1.21 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer - 91172080 Adapter, Low Side - 91172092 Page 7036 panel(s) that can be used as a starting/ stopping point when making a repair. Clearcoat: A clear topcoat required to cover a color basecoat. DELAMINATION: Loss of adhesion between one coat of paint to succeeding coats or coatings. Ultraviolet DELAMINATION is between the E coat (ELPO) and color topcoat(s). ELPO: (Electrocoating or "E" coat): The process by which electrically charged primer is plated on conductive surfaces of an opposite charge. This process provides outstanding corrosion resistance. Guidecoat: A light coat (almost overspray) of color applied over primer surfacer prior to wetsanding to highlight any low spots. Insert Color: The secondary two-tone color between the break line and body side molding. Monocoat: A color topcoat that does not require a clearcoat. Primer: The coating applied to a properly prepared substrate (bare metal) to give adhesion, corrosion and chemical resistance. Primer Sealer: An undercoat that provides maximum adhesion. color coating and corrosion protection. Primer Surfacer: An undercoat used to fill imperfections, with primer qualities, that must be sanded. Refinish: The act of replacing a painted surface, usually undercoat and topcoat. Scuff Sand: A method of sanding a painted surface using a fine grit sandpaper to promote paint adhesion. Topcoat: A finish material over an undercoat material. Ultraviolet Light: The portion of the spectrum of light which can cause fading of paint. It is located below the visible part of the spectrum. V.O.C.: "Volatile Organic Compound" or "Volatile Organic Content" relates to certain emission requirements in specific areas of the country. Page 7293 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 3475 Throttle Position Sensor: Service and Repair Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 6684 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Description and Operation Fillpipe Restrictor: Description and Operation Fuel Filler Neck Fuel Door And Restrictor (Typical) Purpose To prevent refueling with leaded fuel, the fuel filter neck has a built-in restrictor and deflector. The opening in the restrictor will accept only the smaller unleaded gasoline fuel nozzle which must be fully inserted to bypass the deflector. Page 6061 - If low or no vacuum exists at the actuator determine whether the cause is the vacuum harness or the vacuum valve. - Check the vacuum harness first. 4. Vacuum harness circuit check: - Disconnect the vacuum harness at the control head. - The green line should show engine vacuum; if not, trace back through connector to vacuum tank. - To check any individual circuit, place the selector lever at the involved circuit position and check for vacuum presence. Page 1920 Intake Manifold: Technical Service Bulletins Engine - Use of Wacker RTV Sealant for Intake Manifold File In Section: 6 - Engine Bulletin No.: 67-61-17A Date: August, 1996 Subject: Use of Wacker T-330 RTV Sealant (Pronounced Vaucker T) Models: 1990-96 Buick Road master, Estate Wagon 1990-96 Cadillac Fleetwood 1990-96 Chevrolet Camaro, Caprice, Corvette, Impala SS 1990-92 Oldsmobile Custom Cruiser 1990-96 Pontiac Firebird with 4.3L, 5.7L Engine (VINs W, P, 5, 8 - RPOs L99, L98, LT1, LT4) 1990-96 Chevrolet and GMC Light and Medium Duty Trucks with 4.3L, 5.0L, 5.7L, 6.0L, 7.0L, 7.4L Engines (VINs W, Z, E H, K, M, N, P, R - RPOs L35, LB4, L03, L05, LS0, LR0, L19, L30, L31) This bulletin is being revised to add further Chevrolet models. Please discard Corporate Bulletin Number 67-61-17 (Section 6 - Engine). When installing the intake manifold, use a 5 mm (1/4 in.) thick bead of Wacker T-330 RTV, P/N 12346192, on the front and rear sealing areas between Page 855 Figure 1: Full Tread View - "NORMAL" Tire "Feathering" Wear on the Shoulder/Adjacent/Center Ribs Figure 2: Tire Shoulder View Example 1 - "NORMAL" Tire "Feathering" Wear on the Shoulder Figure 3: Tire Shoulder View Example 2 - "NORMAL" Tire "Feathering" Wear Figure 4: Detail Side View of Tire Shoulder Area - "NORMAL" Tire "Feathering" Wear Important When a wheel alignment is deemed necessary for tire wear, be sure to document on the repair order, in as much detail as possible, the severity and type of tire wear (e.g., severe center wear or severe inside or outside shoulder wear) and the position of the tire on the vehicle (RF, LF, LR, RR). Please note the customer's concern with the wear such as, noise, appearance, wear life, etc. A field product report with pictures of the tire wear condition is recommended. Refer to Corporate Bulletin Number 02-00-89-002J and #07-00-89-036C. 4. Other repairs that affect wheel alignment; e.g., certain component replacement such as suspension control arm replacement, engine cradle adjustment/replace, steering gear replacement, steering tie rod replace, suspension strut/shock, steering knuckle, etc. may require a wheel alignment. Important If other components or repairs are identified as affecting the wheel alignment, policy calls for the wheel alignment labor time to be charged to the replaced/repaired component's labor operation time rather than the wheel alignment labor operations. Important Vibration type customer concerns are generally NOT due to wheel alignment except in the rare cases; e.g., extreme diagonal wear across the tread. In general, wheel alignments are NOT to be performed as an investigation/correction for vibration concerns. "Normal Operation" Conditions Vehicle Lead/Pull Due to Road Crown or Slope: As part of "Normal Operation," vehicles will follow side-to-side or left to right road crown or slope. Be sure to verify from the customer the types of roads they are driving as they may not recognize the influence of road crown on vehicle lead/pull and steering wheel angle. If a vehicle requires significant steering effort to prevent it from "climbing" the road crown there may be an issue to be looked into further. Important Page 3724 CHANGES TO MEMCAL/PROM LABELING FORMATS ^ MEMCALs may use either INK-JET or ADHESIVE labels, as shown. ^ PROMs will always use ADHESIVE labels with the same format as shown for MEMCALs. These changes will become effective on parts manufactured after 10/94. Page 7175 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Page 8357 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Isolation Diodes - Replacement Information Diode: Technical Service Bulletins Isolation Diodes - Replacement Information Number: 93-163-8A Section: 8A Date: MAY 1993 Corporate Bulletin No.: 178201R ASE No.: A6 Subject: ISOLATION DIODES REPLACEMENT INFORMATION Model and Year: 1993 AND PRIOR YEAR PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-47-8A, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS PART NUMBERS HAVE BEEN REVISED. THIS WILL ALSO UPDATE CERTAIN SERVICE MANUALS. ALL COPIES OF 92-47-8A SHOULD BE DISCARDED. Many of the electrical systems on our vehicles use a diode to isolate certain circuits and protect them from voltage spikes. Some of the circuits which may use such a diode are listed below: A/C Compressor Clutch ABS/4WAL NOTE: The ABS diode on the Delco Moraine system is hidden inside of an electrical connector under the carpet at the right kick panel. Wiper Charging System (hidden in wire harness) Parking Brake (vehicles with ABS) Relays Solenoids Diesel Glow Plug Circuit Day Time Running Lights Obtaining replacement diodes can sometimes be a problem. A universal diode, that meets the specifications in the chart below, may be used for the applications listed above. Since certain diode applications have specific part numbers, always reference the applicable GM parts catalogue before installing one of the universal diodes listed in this bulletin. When installing the new diode, use the following procedures to obtain a lasting repair: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to current flow direction, remove inoperative diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is needed to attach the new diode. 4. Check current flow direction of the new diode, being sure to install the diode with correct bias. Reference the appropriate service manual wiring schematic to obtain the correct diode installation position. Reference Figure 1 for replacement diode symbols and current flow explanations. Page 8804 Test Steps Fig. 2 Rectangular windshield wiper motor electrical connections Fig. 3 Connections to operate rectangular wiper motor independent of vehicle wiring On models with pulse wipers, disconnect electrical connectors to pulse control module and connect switch and motor harnesses together. If problem is corrected, pulse control is defective. 1. Inspect wiring harness for breaks, loose or improper connections, and repair as needed. 2. Ensure motor and switch are securely mounted, and properly grounded, and repair as needed. 3. Turn ignition on and operate wipers in all switch positions, then place wiper switch in off position with wipers at top of their travel. 4. If motor fails to operate, disconnect electrical connector to motor and check for battery voltage at terminal 2 in connector, Fig. 2, using a test lamp. 5. If lamp fails to light, check and repair feed circuit. 6. If lamp lights, operate motor independent of vehicle wiring as shown in Fig. 3. If motor fails to operate, repeat test with linkage disconnected. 7. If motor still fails to operate, motor is defective. If motor operates, repair linkage. 8. If motor operates properly in step 6, check continuity of wiring between motor and switch. If wiring if satisfactory, replace switch. 9. If motor will not shutoff, or if blades do not park when switch is placed in off position, check for defective park switch or open motor ground and repair as needed. 10. If motor operates properly in all other positions, but will not operate in delay mode, proceed as follows: a. Check feed circuit to pulse control and repair as needed. b. Check continuity of red and black wires between pulse control and wiper switch, and repair as needed. c. If feed circuit and wiring are satisfactory, replace pulse control. A/T - Extension Seal Leaks Seals and Gaskets: All Technical Service Bulletins A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Page 5442 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 104 Blower Motor Relay: Service and Repair Evaporator And Blower Assembly Component View REMOVE OR DISCONNECT 1. Electrical connectors, as necessary. 2. Screws (34). 3. Relay (42). INSTALL OR CONNECT 1. Relay (42). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 2. Screws (34). 3. Electrical connectors, as necessary. - Check circuit operation. Locations Steering Column Multi-function Switch 06-08-111-004B - BULLETIN CANCELLATION NOTIFICATION Body Emblem: Technical Service Bulletins 06-08-111-004B - BULLETIN CANCELLATION NOTIFICATION TECHNICAL Bulletin No.: 06-08-111-004B Date: September 25, 2009 Subject: Information on Discoloration, Blistering, Peeling or Erosion of Various Exterior Emblems Including Chevy Bowtie (Bulletin Cancelled) Models: 2009 and Prior GM Passenger Cars and Trucks (including Saturn) 2003-2009 HUMMER H2 2006-2009 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being cancelled. Please discard Corporate Bulletin Number 06-08-111-004A (Section 08 - Body & Accessories). This bulletin is being cancelled. The information is no longer applicable. Disclaimer Page 4352 Axle Shaft Assembly: Service and Repair GMC Single Speed Axle Axle Housing Refer to CHEVROLET FULL FLOATING AXLES for axle housing replacement procedure. Axle Shaft REAR DRIVE AXLE Removing axle shaft. GMC single speed axle 1. Remove hub cap retaining cap screws and hub cap. 2. Install a slide hammer adapter into tapped hole in axle flange. 3. Attach slide hammer onto adapter and remove axle shaft from housing, Fig. 9. 4. Reverse procedure to install. Lubricate small end of axle shaft and install into housing using a new gasket. Torque axle flange cap screws on 15 ft. lbs. Wheel Bearings REAR WHEEL BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of retainer from slot or flat of locknut, then remove locknut from housing tube, Fig. 6. 3. Disengage tang of retainer from slot or flat of adjusting nut, then remove retainer. 4. Using tool shown in Fig. 6, remove adjusting nut from housing tube. Remove thrust washer. 5. Pull hub and drum assembly off axle housing. Remove oil seal and discard. 6. Using a suitable steel bar and an arbor press, press inner bearing cup from hub. Locations Brake Vacuum Release Valve: Locations Cruise Control Components, Near Steering Column. Page 7375 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Permanent Magnet Motor Wiper Motor: Description and Operation Permanent Magnet Motor Except Models W/Pulse Wipers Fig. 2 Permanent magnet type windshield wiper motor. S/T series except models w/pulse wipers Wiper motor internal components, including permanent magnet fields, armature, brush holder and gear train, are enclosed in a die cast aluminum housing with a plastic cover, Fig. 2. The brush holder contains a circuit breaker and park switch as well as common, low and high speed brushes, and it is located at the gearbox end of the motor. The common brush is connected to ground through the wiper motor ground strap. Battery voltage is supplied to the wiper switch and motor park switch fixed contacts through a fuse in the fuse block. Motor speeds are determined by supplying voltage through the wiper switch to the low or high speed motor brush, and when wiper switch is in off position, voltage supplied to the motor park switch allows wipers to park at the bottom of their travel. Pulse wiper operation, if equipped, is controlled by a variable resistor in the wiper switch and by a pulse module connected between the wiper motor and switch. Standard (Non-Pulse) Wiper Operation When ignition is on, battery voltage is supplied to low and high speed contacts in the wiper switch and to motor terminal 4, Fig. 2. Placing wiper switch in low or high position completes the feed circuit to motor terminal 2 (low speed brush) or terminal 1 (high speed brush), Fig. 2. Current flows through the armature to ground through the common brush, and the motor runs at the selected speed. Placing wiper switch in off position connects the motor low speed brush to park switch terminal 3, Fig. 2. Current flows through the closed park switch contacts, allowing the motor to run at low speed. When wipers reach their lowest point of travel, a cam on the motor output shaft opens the park switch through an actuating lever, and the motor stops. Pulse Wiper Operation In addition to standard wiper system components, models with pulse wipers use a pulse control module and a wiper switch with a variable resistor and additional contacts to control pulse module operation. Current flow between the wiper motor and switch, and battery voltage to the switch pass through the pulse control module. However, when the wiper switch is in off, low or high position, the module does not affect system operation. When the wiper switch is in delay position, voltage is supplied to the pulse module timer through the variable resistor. When the timer circuit becomes fully charged, the timer switch closes, and voltage is supplied to the motor through a second delay terminal in the wiper switch. As the motor begins to operate, the park switch closes, the timer switch opens, and voltage is supplied to the motor through a third delay contact which is linked to the park switch in the wiper switch. When wipers complete their cycle, the park switch opens, the motor stops, and the timer begins to recharge. This cycle repeats as long as wiper switch is in delay position. Delay period is controlled by varying resistance in the pulse module timer feed circuit. Models W/Pulse Wipers Page 4874 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Oxygen Sensors - Silica Contamination Oxygen Sensor: Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Restraints - Seat Belt Warning Lamp On/Buckling Issues Seat Belt Buckle: Customer Interest Restraints - Seat Belt Warning Lamp On/Buckling Issues INFORMATION Bulletin No.: 09-09-40-001A Date: February 02, 2011 Subject: Seat Belt Buckle Latching Issues and/or Seat Belt Warning Lights Illuminated Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7 X Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 09-09-40-001 (Section 09 - Restraints). This bulletin is being published to advise dealers about seat belt buckles not operating and/or seat belt warning light illumination, as well as difficulty latching and unlatching the buckle or the buckle release button sticking. Analysis of warranty data has determined that this condition may be caused by sticky beverages being spilled onto or into the seat belt buckle assembly. Foreign debris from food, candy wrappers, paper and coins can also contribute to this condition. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise the customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. Important Never insert anything other than the seat belt latch plate into the buckle assembly. Do not attempt to dig anything out of a buckle with a tool. Never try to wash out a buckle to remove a spilled liquid as this may damage the buckle. Use the following steps to determine the cause of the concern. 1. Inspect the buckle assembly with a light shining on the latch plate insertion area. Look for any debris or foreign objects in the buckle. 2. If any debris or foreign objects are observed, try to vacuum out the item. After the foreign material is removed, latch and unlatch the seat belt. If the system functions properly, do not replace the seat belt buckle assembly. 3. If the condition has not been corrected, inspect the buckle assembly for any sticky residue. If sticky residue is found, inform the customer that a substance was spilled on the seat belt buckle assembly causing the malfunction. The buckle assembly will need to be replaced at the customer's expense. 4. Refer to SI for seat belt component replacement. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced at the customer's expense. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. 5. If further restraint diagnosis is required, refer to Seat Belt System Operational and Functional Checks in SI. Page 6902 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Initial Inspection and Diagnostic Overview Parking Lamp: Initial Inspection and Diagnostic Overview 1. Check condition of STOP-HAZ and TAIL LPS Fuse(s), if fuse(s) is blown, locate and repair source of overload, replace fuse. Specifications Fluid Pan: Specifications Oil Pan To Case 7-10 ft.lb Oil Pressure Check Plug 6 ft.lb Oil Strainer 14 ft.lb Page 1201 - J 41265 Thread cleaning wire brush - J 41266 Low side port thread restorer - J 41267 High side port thread restorer - J 39037 High side octagon socket - J 41256 Low side octagon socket New low profile, quick connect couplers, J 39500-20A (High side), and J 39500-24A (Low side), have been released as essential tools, to attach to the ACR4 (see Figure 3). These are much smaller couplers than the existing ones, and will allow attachment to the port fittings in much tighter quarters. Page 296 Symbol Identification Page 6142 Installing The Coil Housing 2. Clutch coil (8) to the front head (16). - Align the coil and housing assembly on the compressor front head (16) so that the electrical terminals line up the marks scribed on the compressor. - Align the coil locator projections on the coil housing with the holes in the front head (16). 3. Coil and housing retainer ring (7) with J 6435. Clean Remove any excess adhesive. 4. Pulley and bearing assembly (5 and 6). 5. Clutch plate and hub assembly (2). How to Read A Brake Drum Micrometer Brake Drum: Fundamentals and Basics How to Read A Brake Drum Micrometer HOW TO READ On a standard micrometer each division on the scale is equal to 0.001 inches. To obtain the total drum diameter the measurement shown on the dial is added to the value for which the micrometer scale is set. NOTE: When the dial is at 0.0 the dial indicator styles is fully inserted. When the styles is fully withdrawn the dial is at its maximum value. EXAMPLES In example "A" a new 10 inch drum is being measured. The micrometer scale is set to 10 inches, the styles is fully inserted, and the dial indicates 0.0. The drum diameter is 10.000 inches. In example "B" an older worn 10 inch drum is being measured. The micrometer scale is still set to 10 inches but now the styles is only partially inserted and the dial indicates 90. The total drum diameter is equal to 10.090 inches. Locations Combination Switch: Locations LH Side Of Instrument Panel. On Steering Column Applicable to: Except Bravada Page 3355 Fuel Supply Line: Service and Repair Fuel Tank/Lines Cleaning WARNING: This procedure will NOT remove all fuel vapors. DO NOT attempt any repair on the fuel tank or filler neck where heat or flame is required, as an explosion resulting in personal injury could occur. NOTE: If the fuel is contaminated, or if there is foreign material in the tank, the tank can usually be cleaned. If the tank is rusted internally, it should be replaced. PROCEDURE: 1. Disconnect the negative battery cable. 2. Disconnect the engine harness at the DIS coil module. 3. Place a dry chemical (Class B) fire extinguisher near the work area. 4. Relieve the fuel system pressure, refer to FUEL SYSTEM PRESSURE RELIEF. 5. Drain the fuel tank, refer to FUEL TANK DRAINING. 6. Remove the fuel tank, refer to FUEL TANK REMOVAL AND FUEL LEVEL SENDING UNIT. 7. Remove the external fuel filter and inspect for contamination. If the filter is plugged, replace it. 8. Move the tank away from heat, flame or other source of ignition. Remove the fuel level sending unit and inspect the condition of the strainer. If the strainer is contaminated, install a new strainer when reassembled. 9. Complete draining the tank by rocking it and allowing the fuel to run out of the fuel pump/level sending unit tank opening. 10. Purge the fuel tank, refer to FUEL TANK PURGING. 11. Disconnect the fuel feed pipe at the in-line filter and use air pressure to clean the fuel line. Apply air pressure in the opposite direction the fuel normally flows through the line. Disconnect the return line and apply air pressure to clean. 12. Use low air pressure to clean pipes on the fuel level sender unit assembly. 13. Install a new filter strainer on the fuel level sending unit, if required. 14. Install the fuel level sending unit with a new O-ring gasket into the tank and install the fuel tank. Connect the fuel level sender harness to the body harness. The fuel level lender harness must be routed below the sender unit fuel pipes. Connect all fuel lines except the feed line at the engine. Install the fuel filter. NOTE: Care should be taken not to fold over or twist the strainer when installing the fuel level sending unit as this will restrict the flow. Also, assure that the strainer does not block the float arm full travel. 15. Connect a hose to the fuel feed line at the engine, and insert the other end of the hose into an empty one gallon fuel can. 16. Connect the battery cable. 17. Put 2.3 liters (six gallons) of clean fuel into the fuel tank and apply 12 volts to terminal "G" of the ALDL to operate the fuel pump. Pump two quarts of fuel into the can. This will purge the fuel pump and the fuel lines. 18. Remove the hose and reconnect the fuel line to the engine. Connect the engine harness connector to the DIS ignition module. 19. START the engine. 20. Check all connections for leaks. Tighten all hose clamps. Testing and Inspection Temperature Warning Lamp/Indicator: Testing and Inspection A bi-metal temperature switch located in the cylinder head controls the operation of a temperature indicator light. If the engine cooling system is not functioning properly and/or coolant temperature exceeds a predetermined value, the warning light will illuminate. If the light is not lit when the engine is being cranked, check for a burned out bulb, an open in the light circuit, or a defective ignition switch. If the light is lit when the engine is running, check the wiring between light and switch for a ground, defective temperature switch, or overheated cooling system. As a test circuit to check whether the bulb is functioning properly, connect a wire from the ground terminal of the ignition switch to the temperature indicator light circuit. When the ignition is in the START (engine cranking) position, the ground terminal is grounded inside the switch and the bulb will be lit. When the engine is started and the ignition switch is in the ON position, the test circuit is opened and the bulb is then controlled by the temperature switch. Page 81 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 2323 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Locations Steering Column Multi-function Switch Page 8392 Symbol Identification Page 8368 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Page 2037 For vehicles repaired under warranty use: Description Labor Op. Heater, Engine Block - Replace R4600 Use applicable labor time guide for labor hours. Locations Power Window And Door Lock Body Wiring W/Outside Power Mirrors Capacity Specifications Fluid - A/T: Capacity Specifications THM 180C Total 2.3 qt (US) Pan Only 1.5 qt (US) THM 1700-R4 Total 11.5 qt (US) Pan Only 5 qt (US) Page 3370 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 1102 Fluid - M/T: Fluid Type Specifications Warner T-5 (77MM) 5 Speed Lubricant Type ..................................................................................................................................... .......................................................... Dexron II ATF MUNCIE 5LM60 (HM-290) 4 & 5 Speed Lubricant Type ..................................................................................................................................... ................................ Syncromesh Trans Fluid T2850 Page 2986 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 8556 Symbol Identification Page 2770 ECM Connector C2 Page 6897 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 6835 For vehicles repaired under the terms of this special coverage, submit a claim with the information shown. Customer Reimbursement All customer requests for reimbursement for previous repairs for the special coverage condition will be handled by the Customer Assistance Center, not by dealers. Disclaimer Page 7421 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Removal Brake Drum: Service and Repair Removal Rear Drum Assembly 1. Raise and support vehicle. 2. Remove tire and wheel assembly. 3. Remove brake drum. If brake lining is dragging on brake drum, back off brake adjustment by rotating adjustment screw. If brake drum is rusted or corroded to axle flange and cannot be removed, lightly tap axle flange to drum mounting surface with a suitable hammer. NOTE: For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Page 4287 Pinion Bearing: Service and Repair Corporate and Eaton PINION DEPTH ADJUSTMENT Fig. 9 Pinion Depth Gauge Installation If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly tool No. J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION INSTALLATION 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. Page 4726 NOTICE: When performing the 4WAL brake system bleeding procedure, the ignition switch must be in the "OFF" position or false diagnostic trouble codes could be set to memory. If trouble codes are set, refer to section 5El "Clearing Diagnostic Trouble Codes" in the 1993 Service Manual. Pressure Bleed Procedure The pressure bleeding equipment must be of the diaphragm type. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. IMPORTANT: You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Begin by attaching the pressure bleeder adaptor J29567 to the master cylinder (figure 1). 2. Fill the pressure bleeder tank J29532 at least 2/3 full with Delco Supreme No. 11 Hydraulic Brake Fluid (GM P/ N 1052535) or an equivalent DOT 3 motor vehicle brake fluid. The bleeder tank must be bled each time brake fluid is added. 3. Charge the bleeder tank to 140-170 kPa (20-25 psi) and connect the hose from the bleeder tank to the bleeder adaptor. General Description Control Assembly: Description and Operation General Description The operation of the air conditioning system is controlled by a switch and levers on the control assembly. The compressor clutch and blower motor are connected electrically to the control assembly by a wiring harness. The blower circuit is open in the "OFF" mode. AIR FLOW Air flow is provided by the four blower speeds available in the remaining modes. Cooled and dehumidified air is available in the "MAX," "BI-LEV," and "DEFROST" modes. TEMPERATURE Temperature is controlled by the position of the temperature lever on the control assembly. A cable connects this lever to the temperature valve. It controls air flow through the heater core. As the temperature lever is moved through the its full travel, the cable at the temperature valve connection assures that the temperature valve will seat in both extreme positions. The position of the temperature valve is independent of mode selection. The temperature cable attaches to the air conditioning module. FUNCTIONAL ASSEMBLIES The remaining functional assemblies are controlled the vacuum valve linked to the mode lever of the control assembly. This valve controls the supply of engine vacuum to the appropriate vacuum actuator(s) for the mode selected. Page 4948 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 5719 Stabilizer Shaft: Service and Repair Fig. 16 Stabilizer Bar Replacement. 4 X 2 Models 4 X 2 MODELS 1. Raise and support front of vehicle. 2. Remove stabilizer link bolt nuts from both sides, then pull link bolt from linkage and remove retainers, grommets and spacers, Fig. 16. 3. Remove stabilizer bracket to frame or body attaching bolts, then the stabilizer bar, bushings and brackets. 4. Reverse procedure to install, noting the following: install stabilizer bar so the identification stamping appears on the right side of vehicle. Position the rubber bushings squarely in the brackets with the slit facing the front of vehicle. Torque link nuts and bracket bolts to specifications. Fig. 17 Stabilizer Bar Replacement. 4 X 4 Models 4 X 4 MODELS Refer to Figs. 17, for stabilizer bar replacement procedure on 4 x 4 vehicles. Page 6196 5. With the compressor mounted to the J 25008-A Holding Fixture, position the Rotor and Bearing Assembly on the front head (Fig. 22). Using Rotor and Bearing Installer J 9481-A and Universal Handle J 29886 drive the rotor and bearing assembly onto the front head. With the Installer assembled to the Handle as shown in Figure 22, force will be applied to the inner race of the bearing when installing the assembly onto the front head of the compressor. 6. Install rotor and bearing assembly retainer ring, using Snap Ring Pliers J 6083 (Fig. 9). 7. Reinstall clutch plate and hub assembly as described previously. Locations ABS Main Relay: Locations EHCU Module Mounting The relay is located inside the Electro-Hydraulic Control Unit EHCU, also know as the Brake Pressure Modulator Valve (BPMV). Page 4307 Important: If the original pre-load torque value was < (less than) 3 lb.in., then reset torque specifications to 3-5 lb.in. Important: If the pinion seal and collapsible spacer are replaced, then refer to the appropriate Unit Repair Manual of pinion re-load specifications. 4. Install the "Dual Double Cardon" two piece propeller shaft and attaching bolts and nuts. 5. Apply a coating of GM P/N 12345382 Thread Lock or Loctite(R) # 242 or equivalent to the mounting bolt threads to flange. Tighten Tighten bolts to 50 Nm (37 lb.ft.). 6. Install the rear axle brake drum and wheel assemblies. 7. Add lubricant to the rear axle as necessary. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty. Locations Electronic Spark Control (ESC) Module Page 5190 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 8267 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 8420 Front Park And Marker Lamps Page 7277 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 4131 For vehicles repaired under warranty use: Page 6767 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 5450 Relay Box: Electrical Diagrams Convenience Center (without Digital Cluster) Engine - Hard Start or No Start Fuel Pressure Pulsation Damper: Customer Interest Engine - Hard Start or No Start File In Section: 6E - Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks It the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description QTY 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Labor Op Description Labor Time J 5590 Pump, Fuel R&R; Use Published Labor Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Page 8738 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Fastener Tightening Specifications Wheel Fastener: Specifications Wheel Lug Nuts Aluminium wheels 90 ft.lb Steel wheels 73 ft.lb Page 7098 Page 2858 Quad Driver: Service and Repair Quad/Output drivers are hard wired onto the ECM/PCM/VCM, and can't be serviced separately. Page 2140 Spark Plug: Specifications Spark Plugs 22 ft.lb Page 6727 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Initial Inspection and Diagnostic Overview Driver Information Center (DIC): Initial Inspection and Diagnostic Overview 1. Check condition of IGN/GAU, BRAKE and INST LPS Fuse(s). If fuse(s) s blown, locate and repair source of overload. Replace fuse(s). Wheels - Sealing Leaking Cast Aluminum Wheels: All Technical Service Bulletins Wheels - Sealing Leaking Cast Aluminum Bulletin Number: 93-3-16 Reference Number: 393504 Publish Date: 7/93 Subject: LEAKING CAST ALUMINUM WHEELS (REPAIR WITH ADHESIVE SEALANT) Models Affected: 1985-1993 ALL MODELS Should a vehicle equipped with cast aluminum wheels exhibit a slow leak due to a porous condition existing in the wheel, the wheel can be repaired by using Dow Corning Silastic 732 RTV, p/n 1052366 or equivalent, as described in the following procedure: 1. Remove tire-wheel assembly from vehicle. 2. Locate leaking area by inflating tire to 40 psi and dipping tire-wheel assembly in water bath. 3. If air bubbles are observed, mark leak area and remove tire from wheel. 4. Scuff INSIDE rim surface at leak area with # 80 grit paper and clean area with general purpose cleaner, such as 3M # 08984. 5. Apply 1/8" thick layer of adhesive/sealant to leak area on INSIDE of rim and allow six hours of drying time. 6. Mount tire on wheel, pressurizing to 40 psi and check for leaks. NOTICE: Caution must be used when mounting the tire so as not to damage the sealer. 7. Adjust tire pressure to meet placard specification. 8. Balance tire-wheel assembly, using proper coated weights. 9. Water test wheel again. 10. Reinstall tire-wheel assembly on vehicle. Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation Number: E0420 Page 5320 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Component Locations Blower Motor: Component Locations Blower Motor Heater Components. RH Side Of Dash Panel, In Engine Compartment Applicable to: Vehicles Less A/C Heater & A/C Components Page 8271 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 6380 Page 4585 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Locations Steering Column Multi-function Switch Page 4449 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 2396 PURPOSE The catalytic converter is an emission control device added to the exhaust system to effectively reduce the levels of carbon monoxide, hydrocarbons, and in some cases oxides of nitrogen, entering the atmosphere. The converter serves two purposes: it permits a faster chemical reaction to take place and although it enters into the chemical reaction, it remains unchanged, ready to repeat the process. CONSTRUCTION AND OPERATION General Motors uses four different converter designs in conjunction with two types of catalysts. The four converter designs, are: single bed monolith, dual bed monolith, single bed pellet and dual bed pellet. The two types of catalysts used are an oxidation catalyst and a three-way (reduction) catalyst. The oxidation catalyst is coated with material containing platinum and palladium which lowers levels of carbon monoxide and hydrocarbons. The three-way (reduction) catalyst is coated with platinum and rhodium which lowers levels of oxides of nitrogen (NOx), as well as carbon monoxide and hydrocarbons. All dual bed converters, whether monolith or pellet type, contain both oxidation and three-way catalysts. Due to its high operating temperatures, the catalytic converter usually requires the use of heat shields. Heat shields are necessary to protect chassis components, passenger compartment and other areas from heat related damage. A fill pipe restrictor is used on catalytic converter equipped vehicles, to prevent the larger service station pump nozzle, used for leaded fuels, being inserted into the filler tube. Since the use of leaded fuels contaminates the catalysts, rendering them ineffective, the use of unleaded fuels is mandatory in catalytic converter equipped vehicles. Page 6656 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. A/T - DEXRON(R)-VI Fluid Information Fluid - A/T: Technical Service Bulletins A/T - DEXRON(R)-VI Fluid Information INFORMATION Bulletin No.: 04-07-30-037E Date: April 07, 2011 Subject: Release of DEXRON(R)-VI Automatic Transmission Fluid (ATF) Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks 2003-2008 HUMMER H2 2006-2008 HUMMER H3 2005-2007 Saturn Relay 2005 and Prior Saturn L-Series 2005-2007 Saturn ION 2005-2008 Saturn VUE with 4T45-E 2005-2008 Saab 9-7X Except 2008 and Prior Chevrolet Aveo, Equinox Except 2006 and Prior Chevrolet Epica Except 2007 and Prior Chevrolet Optra Except 2008 and Prior Pontiac Torrent, Vibe, Wave Except 2003-2005 Saturn ION with CVT or AF23 Only Except 1991-2002 Saturn S-Series Except 2008 and Prior Saturn VUE with CVT, AF33 or 5AT (MJ7/MJ8) Transmission Only Except 2008 Saturn Astra Attention: DEXRON(R)-VI Automatic Transmission Fluid (ATF) is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids. Supercede: This bulletin is being revised to update information. Please discard Corporate Bulletin Number 04-07-30-037D (Section 07 - Transmission/Transaxle). MANUAL TRANSMISSIONS / TRANSFER CASES and POWER STEERING The content of this bulletin does not apply to manual transmissions or transfer cases. Any vehicle that previously required DEXRON(R)-III for a manual transmission or transfer case should now use P/N 88861800. This fluid is labeled Manual Transmission and Transfer Case Fluid. Some manual transmissions and transfer cases require a different fluid. Appropriate references should be checked when servicing any of these components. Power Steering Systems should now use P/N 9985010 labeled Power Steering Fluid. Consult the Parts Catalog, Owner's Manual, or Service Information (SI) for fluid recommendations. Some of our customers and/or General Motors dealerships/Saturn Retailers may have some concerns with DEXRON(R)-VI and DEXRON(R)-III Automatic Transmission Fluid (ATF) and transmission warranty claims. DEXRON(R)-VI is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids (except as noted above). Please remember that the clean oil reservoirs of the J-45096 - Flushing and Flow Tester machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI for testing, flushing or filling General Motors transmissions/transaxles (except as noted above). DEXRON(R)-VI can be used in any proportion in past model vehicles equipped with an automatic transmission/transaxle in place of DEXRON(R)-III (i.e. topping off the fluid in the event of a repair or fluid change). DEXRON(R)-VI is also compatible with any former version of DEXRON(R) for use in automatic transmissions/transaxles. DEXRON(R)-VI ATF General Motors Powertrain has upgraded to DEXRON(R)-VI ATF with the start of 2006 vehicle production. Current and prior automatic transmission models that had used DEXRON(R)-III must now only use DEXRON(R)-VI. Page 765 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 53 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 5140 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Page 6401 Omega Refrigerant Reclamation 5263 North Fourth St. Irwindale, CA 91706 310-698-0991, FAX 310-696-1908 Refrigerant Management Svcs of Georgia 216 F. Atlanta Hwy. Cumming, GA 30130 Ph/FAX 800-347-5872 Refrigerant Reclaim Inc. 122 Old Stage Coach Rd. Dumfries, VA 22026 800-238-5902, FAX 703-441-0393 Gartech Refrigerant Reclamation Ctr. 2002 Platinum Garland, TX 75042 214-272-4070, FAX 214-272-8548 National Refrigerants, Inc. 11401 Roosevelt Blvd. Philadelphia, PA 19154 215-698-6620, FAX 215-602-8205 CFC Reclamation 1321 Swift North Kansas City, MO 64116 816-471-2511 Full Cycle-Global 550 James Street Lakewood, NJ 08701 908-370-3400, FAX - 908-370-3088 Refrigerant Reclaim Svcs, Inc. dba Full Cycle-Global 121 S. Norwood Drive Ft. Worth, TX 76053-7807 817-282-0022, FAX - 800-831-6182 Full Cycle-Global 2055 Silber, Ste. 109 Houston, TX 77055 713-681-7370, FAX - 713-681-9947 Full Cycle-Global 343 South Airline Hwy. Gonzales, LA 70737 504-644-5303, FAX - 504-644-1809 Full Cycle-Global 2966 Wireton Blue Island, IL 60406 708-388-8551, FAX - 708-388-8550 Page 2055 NOTE: The gears must mesh in order to prevent damage to the camshaft retainer. 4. Install camshaft sprocket bolts. CAUTION Be sure to align the camshaft and the crankshaft sprocket marks. Timing marks (Number 4 Firing). ^ Tighten bolts to 28 Nm (21 ft. lbs.) 5. Align the keyway on the reluctor ring with the key in the crankshaft. 6. Install the reluctor ring onto the crankshaft until the ring is completely seated against the crankshaft sprocket. 7. Install the timing cover. Page 4558 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Specifications Refrigerant Oil: Specifications REFRIGERANT OIL TYPE - R-12 refrigerant oil, 525 viscosity. NOTE: If vehicle has been converted to R-134a use PAG (Polyalkaline Glycol) synthetic refrigerant oil (GM Part No. 12345923) or equivalent. Page 6948 Page 3034 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 5862 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Engine - Noise/Damage Oil Filter Application Importance Oil Filter: Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Page 4280 for models with 8-1/2 or 8-7/8 inch ring gear, Figs. 16 and 17, or suitable equivalents. On models with 8-7/8 inch ring gear, substitute cloverleaf gauge plate J-21777-36 for plate J-21777-29. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate onto preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque are required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. e. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. f. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold drive shaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 9 1/2 Inch Ring Gear Page 1792 For vehicles repaired under warranty, use: Page 1302 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 6187 It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Installing Pulley Rotor Bearing 1. Place the pulley rotor on the J 21352-A support block to fully support the rotor hub during bearing installation. NOTICE: Do Not support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using puller and bearing installer J 9481-A with universal handle J 29886, drive the bearing fully into the hub. The installer will apply force to the outer race of the bearing if used as shown. 3. Place bearing staking guide J 33019-1 and bearing staking pin J 33019 in the hub bore as shown in Figure Staking Bearing In Rotor Hub Bore 13. Shift the rotor and bearing assembly on the J 21352-A support block to give full support of the hub under the staking pin location. A heavy-duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide after each impact on the pin. 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to but not touching the bearing. Page 3020 Manual Transmission Shift Light Circuit Circuit Description: The ECM uses information from the following inputs to control the shift light: ^ Coolant Temperature Sensor (CTS) ^ Throttle Position Sensor (TPS) ^ Vehicle Speed Sensor (VSS) ^ RPM The ECM uses the measured rpm and the vehicle speed to calculate what gear the vehicle is in. It's this calculation that determines when the shift light should be turned "ON". Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. This should not turn "ON" the shift light. If the light is "ON", there is a short to ground in CKT 456 wiring, or a fault in the ECM. 2. This should turn "ON" the shift light 3. This checks for an open in the shift light circuit, or a faulty ECM. Page 7084 The AFFECTED AREAS MAY REQUIRE RECLEARCOATING/COLORCOATING OR REFINISHING. 8. In any case, once the proper repairs have been made, the final step in the repair process involves polishing the vehicle. A WORD ABOUT CLEARCOAT THICKNESS The clearcoat on the vehicle is typically 1.5 to 2.0 mils thick (one mil equals .001" or 1/1,000 of an inch). At least one mil thickness is required to provide lasting protection to the vehicle basecoat. PAINT GAGES The best way to accurately measure how much clearcoat has been removed is to use a paint gage before, during and after the sanding process. Paint gages measure the total thickness of the finish and when used, can determine how much clearcoat has been removed during the repair process. Paint gages range from magnetic pull types to sophisticated electronic types, are available from a variety of sources, and can cost from $30 to $1800. The older magnetic type gages, at best, a +/- 5% accuracy range and are not sensitive enough to detect removal of .5 mil clearcoat. The newer type magnetic gages have improved accuracy ranges. Most gages are confined to checking either a ferrous metal (steel) or non-ferrous metal (aluminum) panels. At this time, there are no viable gages for reading film thickness on non-metallic panels. A more sophisticated gage is the digital Elcometer 300 fn Paint Thickness gage (or equivalent). It has an ability to read film thickness on both ferrous and non-ferrous metal panels. This instrument has an accuracy range of +/- 1% and has thickness standards included for recalibration. Approximate cost = $1750. An alternative (for use on steel panels only) would be the digital Elcometer 246 model, or equivalent. This gage has a +/- 3% accuracy range and include thickness standards for recalibration. Approximate cost - $575. REPAIRING RAIL DUST DAMAGE Rail dust damage comes from the tiny iron particles produced from the friction between the train wheels and the track. It can also be deposited on vehicles if stored near any operation producing iron dust (steel ore yards, etc.). This dust can either lay on top of, or embed into the paint surface. It is usually diagnosed as; bumps in the paint surface OR - rust colored spots in the paint. PROCEDURE: 1. Wash the vehicle with soap and water, dry it and clean the affected area with wax and grease remover. 2. Keeping the vehicle in a cool or shaded area, rinse the surface with cold water. CAUTION: RAIL DUST REMOVER (OXALIC ACID) IS AN ACIDIC SUBSTANCE CONTAINING CHEMICALS THAT WILL BREAK DOWN THE IRON PARTICLES EMBEDDED IN THE FINISH. WHEN WORKING WITH IT, USE THE NECESSARY SAFETY EQUIPMENT, INCLUDING GLOVES AND GOGGLES. FOLLOW THE MANUFACTURER'S DIRECTIONS CLOSELY BECAUSE IT MAY REQUIRE SPECIAL HANDLING AND DISPOSAL. 3. Soak several terry cloth towels in a container of rail dust remover solution and, after the damaged areas have been rinsed with cold water, lay the wet towels on the damaged areas. 4. Allow the towels to remain in place for 20 minutes, keeping them moist by spraying with water and not allowing to dry on the surface of the vehicle. 5. After 20 minutes of applying the towels, remove them and rinse the area thoroughly with cold water. Inspect the affected area to ensure the dust has been removed. Use both touch (feeling for bumpy surface) and sight (magnifying glass for close inspection). 6. If upon inspection some particles are still present, the process of applying the towels can be repeated 3 times. 7. Select a test area and hand wet sand with American ultra fine 1,500 grit to 2,000 grit sandpaper to repair damage (surface pitting from dust). a. Use ample amounts of water. b. Go slow to prevent removing too much clearcoat. NOTICE: USE A PAINT GAGE TO DETERMINE THE AMOUNT OF CLEARCOAT REMOVED. IF TOO MUCH HAS BEEN REMOVED, ADDITIONAL CLEARCOAT WILL HAVE TO BE APPLIED. IF RAIL DUST HAS PENETRATED INTO THE BASECOAT, THE PANEL REQUIRES REFINISHING. MAKE SURE ALL RAIL DUST HAS BEEN REMOVED PRIOR TO REFINISHING OR THE RUST SPOTS WILL RETURN, CAUSING CUSTOMER COMEBACKS. 8. If the damage has been repaired, complete the repair to the entire panel. 9. Once the damage has been repaired, the final step in the repair process involves polishing the vehicle. PREVENTING INDUSTRIAL FALLOUT DAMAGE Page 1135 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Distributor Operation Distributor: Description and Operation Distributor Operation EST Distributors With Separate Coil (Typical) Page 3504 Throttle Position Sensor: Adjustments N/A: TPS is not adjustable on this engine. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Page 5245 Convenience Center (with Digital Cluster) Page 1086 Fluid - A/T: Technical Service Bulletins A/T - DEXRON III Fluid Introduction File In Section: 0 - General Information Bulletin No.: 57-02-01 Date: March, 1995 SERVICE MANUAL UPDATE Subject: Section 0 - General Information - DEXRON(R)-III Transmission Fluid Introduction Models: 1995 and Prior Passenger Cars and Trucks General Motors has phased in a new automatic transmission fluid, DEXRON(R)-III, that does not need replacing under normal service. DEXRON(R)-III is designed to help the transmission deliver the best possible performance under all conditions. Refer to Figure 1. The improvements in DEXRON(R)-III include better friction stability, more high temperature oxidation stability and better material compatibility. DEXRON(R)-III has the same low temperature fluidity as DEXRON(R)-IIE, for better transmission performance in cold weather. DEXRON(R)-IIE and DEXRON(R)-III are fully compatible. DEXRON(R)-III is fully compatible with any General Motors passenger vehicle or light truck with automatic transmission and built since 1949. Dealers should require their supplier to include the DEXRON(R)-III license number on all automatic transmission fluid invoices. Starting February 1, 1994 DEXRON(R)-III was phased into all North American assembly plants. DEXRON(R)-III fluid is available from GMSPO (see fluid numbers below): U.S. 1 Quart 12346143 Page 58 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Campaign - 02-313 Stop Delivery Notice Update Fuel Level Sensor: Recalls Campaign - 02-313 Stop Delivery Notice Update ** ADMINISTRATIVE MESSAGE 01-277 CREATED ON 9/5/91 AT PAGE 1 OF 1 TO: ALL CHEVROLET DEALERS SUBJECT: STOP DELIVERY NOTICE 1992 S/T TRUCKS THIS IS WITH FURTHER REFERENCE TO THE 1992 S/T TRUCK STOP DELIVERY DCS ADMIN MESSAGE 01-258 DATED 8/22/91 SENT TO ALL CHEVROLET DEALERS. SELECT DEALERS WERE ADVISED IN DCS MESSAGE 02-313 DATED 9/5/91 OF PRODUCT CAMPAIGN 92C02 FUEL LEVER SENDER ARM/TANK INTERFERENCE. THIS DCS INCLUDED INVOLVED DEALER CODES AND INVOLVED VIN'S. ANY DEALER NOT RECEIVING DCS ADMIN MESSAGE 02-313 HAS NO INVOLVED VEHICLES ASSIGNED AND VIN'S WHICH FALL WITHIN THE ORIGINAL VIN RANGES LISTED BELOW ARE RELEASED FROM THE STOP DELIVERY. ASSEMBLY PLANT STARTING VIN ENDING VIN PONTIAC WEST N0100014 N0101228 MORAINE N2100052 N2101700 SHREVEPORT N8100014 N8101560 PLEASE COMMUNICATE THIS INFORMATION TO ALL DEALERSHIP MANAGEMENT IMMEDIATELY UPON RECEIPT. Page 8628 - The split post guide clips with new solid post guide clips (Figure 2, Views A and B). The material in the new clip has been changed and the post redesigned. The material change is not evident, but provides additional strength in the clip hinge area. The new post is solid instead of split providing better fastening characteristics (Figure 2, View A). The purpose of the guide clips is to keep the glass parallel to the door frame when the glass is cycled. SERVICE PROCEDURE: 1. Remove the window glass. Follow the "Front Door Window Replacement" instructions in "Section 10A1-Door" of the applicable Service Manual. 2. Install new redesigned guide clips on the new glass. Glass P/N's 15960877-LH and 15960878-RH for non-export vehicles or P/N's 15962245-LH and 15962246-RH for export vehicles (RPO A26). - Align the clips with the holes in the glass and carefully snap together securely at each fastener location. The clips attach to the rear upper edge and front lower edge of the front door glass through holes in the glass (Figure 2, View B). 3. Remove three screws from the weatherstrip in the run assembly and remove the weatherstrip (Figure 1). 4. Install a new low friction run assembly weatherstrip, P/N 15960867-LH or 15960868-RH (Figure 1, Section A-A). Torque the fastening screws to 1.6 - 2.2 N-m (13 - 18 lbs.in.). Ensure the weatherstrip is properly seated in the door run channels. (Special care should be taken to ensure the weatherstrip below the door daylight opening is also properly seated). Apply silicone spray lubricant to the lower portion of the run assembly as indicated in illustration. 5. Install the new glass assembly (with new guide clips). Follow "Front Door Window Replacement" instructions in "Section 10A1-Doors" in the applicable Service Manual. 6. Check for proper window operation. Page 7374 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 7600 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 4137 SERVICE PARTS INFORMATION WARRANTY INFORMATION Page 5117 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 4564 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 2437 ECM QDR Check Procedure Page 1455 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Page 2220 SERVICE PARTS INFORMATION RPO DEFINITIONS: C60 - AIR CONDITIONER, FRONT, MANUAL CONTROLS C41 - HEATER, OUTSIDE AIR W/FAN AND DEFROSTER C42 - HEATER, DELUXE GU2 - AXLE REAR 2.73 RATIO GU4 - AXLE REAR 3.08 RATIO GU5 - AXLE REAR 3.23 RATIO GU6 - AXLE REAR 3.42 RATIO GT4 - AXLE REAR 3.73 RATIO K01 - FAN CLUTCH DRIVE L84 - ENGINE, 4.3L, (4.3Z) V6 LU2 - ENGINE, 4.3B, (4.3B) V6 HI-OUTPUT TBI L35 - ENGINE, 4.3L, (4.3W) CENTRAL PORT INJECTION V6 90 DEG WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Op: J3390 Labor Time: See Applicable Labor Time Guide Page 406 Cruise Control Switch: Service and Repair Fig. 40 Mode control replacement 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect mode control connector from main harness connector and attach a suitable length of flexible wire to mode control harness. 3. Tape joint between wire and control harness to aid removal, then remove control assembly as shown in Fig. 40. 4. Reverse procedure to install. Page 5018 Symbol Identification Page 6608 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 5171 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Locations Daytime Running Lamps, I/P Wiring Page 3742 [222] Surge or chuggle on decel and/or rough idle. PROM CAN ONLY BE USED WITH ECM P/N 16144288. [223] Engine stall. MANUAL TRANSMISSION CARS SHOULD ALSO BE UPDATED WITH THE CLUTCH ANTICIPATE SWITCH PER DEALER SERVICE BULLETIN NO. 91-472-7C. [224] USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [225] USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [226] USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [227] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [228] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [229] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [230] Surge or chuggle on decel and/or rough idle. PROM CAN ONLY BE USED WITH ECM P/N 16144288. [231] MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [232] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [233] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [234] Driveablity improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [235] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [236] Center Port Fuel Injection noise. FOR VEHICLES WITH SLEEVE BEARING ENGINES. [237] Neutral gear rattle only. COMBINATION DETONATION AND NEUTRAL GEAR RATTLE PROM AVAILABLE. [238] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [239] TCC chuggle. MODEL 2DDM TRANSMISSIONS - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED BCC: DG5F) NEED TO REPLACE IT WITH P/N 8650935. [240] Unstable idle in park or neutral/poor driveability. FOR DEDICATED NATURAL GAS VEHICLES. ORDER WITH KIT P/N 12545589 UNLESS THE ONLY PROBLEM IS IDLE FLUCTUATION. [241] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [242] Information on PROM calibrations. CANNOT BE USED ON VEHICLES THAT DO NOT HAVE DIGITAL EGR VALVES. Locations Fog Lamp Switch And Relay Wiring Page 4668 MACHINING Since accurate control of the rotor tolerances is necessary for proper performance of the disc brakes, machining of the rotor should be done only with precision equipment. NOTE: 1 inch = 25.4mm, so if your micrometer measures in inches and the specified thickness on the disc is in millimeters, convert millimeters to inches by dividing the specified number of millimeters by 25.4. Example: Specification on disc is 17.8 mm. Dividing 17.8mm by 25.4mm/in = 17.8/25.4 = 0.70 inches. Page 3893 Page 5919 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Page 2238 Figure 1 - Typical Fan Assembly Important To maintain a balanced fan assembly, align the yellow paint mark on the fan clutch with the yellow paint mark on the water pump hub (Figure 1.) Body - Vehicle Glass Distortion Information Front Door Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 4592 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 7251 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 1317 Symbol Identification Page 392 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 7328 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 662 Throttle Position Sensor: Mechanical Specifications Throttle Position Sensor 18 in.lb Page 7665 Symbol Identification Borg Warner Pinion Gear: Adjustments Borg Warner 2 - Pinion Fig. 8 Pinion gauge plate installation Fig. 9 Checking pinion depth Page 1456 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Recall 99V193000: ABS 4WD Switch Defective 4WD Switch: Recalls Recall 99V193000: ABS 4WD Switch Defective Description: Certain 4-wheel drive pickup trucks and sport utility vehicles equipped with ABS (antilock braking system) manufactured from September 1989 through August 1996. Under certain driving conditions the switch which signals the ABS system whether the vehicle is in 2-wheel or 4-wheel drive can malfunction causing increased stopping distances during ABS stops while in the two-wheel drive mode. If this occurred at a time when minimum stopping distance was required, a vehicle crash could occur without prior warning. Dealers will replace or repair the 4-wheel/2-wheel drive switch. The first phase of owner notification letters began May 31, 2000, with the last mailing completed by October 2000. Owners can contact Chevrolet at 1-800-222-1020 or GMC at 1-800-462-8782. Also contact the National Highway Traffic Safety Administration's Auto Safety Hotline at 1-888-DASH-2-DOT (1-888-327-4236). Page 3733 [76] For vehicles with sleeve bearing engines. [77] Combination detonation and neutral gear rattle PROM available. [78] Needs ESC P/N 16175099. [79] Model 2DDM Transmissions - Check dealer records to see if the torque converter has already been replaced with P/N 8650935 (Tagged BCC: DGAF). Trans. with torque converters with P/N 8656959 (Tagged BCC: DG5F) need to replace it with P/N 8650935. [80] For dedicated natural gas vehicles. Order with kit P/N 12545589 unless the only problem is idle fluctuation. [81] For chuggle at 40-45 condition, use PROM only. For tip-in hesitation only, use EGR valve only - P/N 17078431. For cold driveability hesitation, use both PROM and EGR. [82] Requires supplementary tune-up label, spark bypass relay kit P/N 14086983, spark plugs P/N 5614009, sun visor starting label P/N 14085150. Also, remove and discard fuse labeled "crank" from fuse BLK #2 position (3 Amp. Fuse). [83] Manual transmission cars should also be updated with the clutch anticipate switch per dealer service bulletin number. 91-472-7C. [84] Cold driveability, use with PROM 0051 AAF (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [85] Cold driveability, use with PROM 0050 AAF (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [86] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5884 BH (G057). REQUIRES THROTTLE BODY SERVICE P/N 17068019, EGR VALVE SERVICE P/N 17067109, INJECTOR SERVICE KIT P/N 17067976. [87] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5869 BH (G057). REQUIRES THROTTLE BODY SERVICE P/N 17068019, EGR VALVE SERVICE P/N 17067109, INJECTOR SERVICE KIT P/N 17067976. [88] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5779 KB (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067110, INJECTOR SERVICE KIT P/N 17067976. [89] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5778 KB (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067110, INJECTOR SERVICE KIT P/N 17067976. [90] Cold driveability, use with PROM 5854 KJ (G057). PROM I.D. 7080 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5853 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [91] Cold driveability, use with PROM 5853 KJ (G057). PROM I.D. 7080 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5853 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [92] Cold driveability, use with PROM 5861 KK (G057). REQUIRED THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. [93] Cold driveability, use with PROM 5860 KK (G057). REQUIRED THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. [94] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5786 LW (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107, INJECTOR SERVICE KIT P/N 17067976. [95] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5785 LW (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107, INJECTOR SERVICE KIT P/N 17067976. [96] Cold driveability, use with PROM 7088 LY (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [97] Cold driveability, use with PROM 7087 LY (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [98] Chuggle at 40-45 mph, cold driveability hesitation. FOR CHUGGLE AT 40-45 CONDITION, USE PROM ONLY. FOR TIP-IN HESITATION ONLY, USE EGR VALVE ONLY - P/N 17078431. FOR COLD DRIVEABILITY HESITATION, USE BOTH PROM AND EGR. Tools - Keyless Entry Transmitter Tester Keyless Entry Transmitter: Technical Service Bulletins Tools - Keyless Entry Transmitter Tester File In Section: 9 - Accessories Bulletin No.: 83-90-12 Date: August, 1998 INFORMATION Subject: Essential Tool J 43241 Remote Keyless Entry and Passive Keyless Entry Transmitter Tester Models: 1990-99 Passenger Cars and Trucks with Remote Keyless Entry or Passive Keyless Entry Systems A new essential tool, J 43241 Remote Keyless Entry Transmitter Tester, has been sent to all GM Dealers. This tester can be used on all RKE and PKE systems, on past as well as current models. Page 7669 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 1763 Valve: Specifications Valve Arrangement All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E Page 5027 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 5098 Symbol Identification Page 775 Neutral Safety Switch: Service and Repair Manual Transmission 1. Disconnect battery ground cable. 2. Disconnect back-up lamp switch electrical connector. 3. Disconnect switch wiring from transmission bracket, four-wheel drive vehicles only. 4. Remove switch from transmission. 5. Reverse procedure to install. Removal Brake Rotor/Disc: Service and Repair Removal Fig. 5 Hub, knuckle & bearing components. 1. Raise and support vehicle 2. Remove brake caliper. See Brake Caliper / Service and Repair. See: Brake Caliper/Service and Repair 3. Remove cap from hub/disc assembly, Fig. 5. 4. Remove cotter pin, nut and washer. 5. Remove hub/disc from spindle. 6. Remove outer bearing, seal, inner bearing and cup. Page 6227 Tools Required: J 9399-A Compressor Shaft Nut Socket J 9401-A Hub and Drive Plate Assembly Installer J 25030-A Clutch Hub Holding Tool 1. Shaft key (36). Aligning The Drive Plate Key - Allow the shaft key (36) to extend 4.5 mm (3/16-inch) out of the bottom of the hub keyway. - The shaft key (36) is curved to give an interference fit in the groove. Important Do not drive or pound or the clutch hub or the shaft (39). Internal damage to the compressor may result. 2. Clutch plate and hub assembly (2). - Install the clutch plate and hub assembly (2) over the compressor shaft lining up the key slot on the hub with the keyway slot in the shaft. Sunshade - Replacement Availability Sun Shade: Technical Service Bulletins Sunshade - Replacement Availability File In Section: 08 - Body and Accessories Bulletin No.: 99-08-110-005 Date: June, 1999 INFORMATION Subject: Sunshade Replacement Models: 1999 and Prior Chevrolet and GMC Light Duty Trucks This bulletin is to inform dealers that new replacement sunshades are being introduced for service on approximately July 19, 1999. These new replacement sunshades will no longer have the map strap feature. The part numbers for these replacement sunshades will remain the same as the previous parts. Once these new sunshades become available, current replacement sunshades on hand may be used at the customer's/dealer's discretion. Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 7562 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 3997 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 7457 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 4549 Figure 7 Figure 8 Figure 9 Figure 10 Page 8561 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Locations Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Locations Dome Lamp Relay: Locations Part Of Rear Dome Lamp Assembly Temp Gage Indic. Hot W/ENG Cool Below Oper Temp and Ign In Run Temperature Gage Indicates Hot With Engine Coolant Below Operating Temperature And Ignition Switch In RUN Page 7432 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 5504 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Page 1729 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Page 4671 Brake Rotor/Disc: Service and Repair Installation Fig. 5 Hub, knuckle & bearing components. 1. Apply an approved high temperature front wheel bearing grease to the spindle at the inner and outer bearing seat, shoulder and seal seat. Also finger apply a small amount of grease inboard of each bearing cup in the hub/disc assembly. Pressure pack the bearings with a grease machine or hand pack them. Ensure grease is worked thoroughly into the rollers, cone and cage. 2. Install inner bearing, (apply an additional quantity of grease outboard of the inner bearing), and seal. 3. Install rotor. 4. Install outer bearing, washer and nut. 5. Torque nut to 13-16 Nm (10-12 ft lb) while turning the wheel assembly forward by hand. 6. Loosen nut to a just loose position, then back nut off until hole in the spindle aligns with a slot in the nut. CAUTION: Do not back the nut off more than 1/2 flat. 7. Install cotter pin and cap. 8. Install caliper. See Brake Caliper / Service and Repair. See: Brake Caliper/Service and Repair 9. Install wheel and tire assembly. 10. Lower vehicle. 11. Depress brake pedal. Page 7607 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 4269 Fluid - Differential: Fluid Type Specifications Locking Differential (G80) This Article has been updated by TSB # 76-02-02A. SAE 80W-90 GL5 Gear Lubricant, GM P/N 1052271. Do not use limited slip additive. Non-Locking Differential Rear Axle with Non Limited Slip or Non Locking Differentials HD-3500 Trucks (Dana 11.0 axles) Recommended Lubricant - GM P/N 12346140, SAE 75W-140 Synthetic Gear Lubricant. 1999 GMT 800 Trucks Recommended Lubricant - GM P/N 12378261, SAE 75W-90 Synthetic Axle Lubricant. All other non limited-slip or non locking differentials including B and D cars, S/T, M/L, G, P, and C/K trucks except GMT 800 trucks, and as noted above. Recommended Lubricant - GM P/N 1052271 or an SAE 80W90 GL-5 Gear Lubricant. Page 4388 Fig. 19 Aligning Bearing Cups & Journals Fig. 20 Relieving Binding Condition At Point A Fig. 21 Relieving Binding Condition At Point B Page 8482 Headlamp Switch: Service and Repair 1. Disconnect battery ground cable. 2. Remove headlamp switch trim plate and switch assembly attaching screws. 3. Disconnect electrical connectors from headlamp switch, then remove switch assembly from dash panel. 4. Reverse procedure to install. Page 772 Neutral Safety Switch: Description and Operation Fig. 4 Mechanical Lockout. Except Tilt Column Fig. 5 Mechanical Lockout. Tilt Column Actuation of the ignition switch is prevented by a mechanical lockout system, Figs. 4 and 5, which prevents the lock cylinder from rotating when the selector lever is out of Park or Neutral. When the selector lever is in Park or Neutral, the slots in the bowl plate and the finger on the actuator rod align, allowing the finger to pass through the bowl plate in turn actuating the ignition switch. If the selector lever is in any position other than Park or Neutral, the finger contacts the bowl plate when the lock cylinder is rotated, thereby preventing full travel of the lock cylinder. Locations Exhaust Layout S/T 2WD PUP 4.3L Locations Steering Column Multi-function Switch Page 1169 Vehicle Limited Warranty, dealers are instructed to proceed as follows: Important: On vehicles equipped with A/C systems NOT produced by GM (i.e., rear A/C systems in van conversions), consult the manufacturer of that A/C system for retrofit guidelines. ^ Offer the customer the option of repairing and recharging the system with R12, or retrofitting after repair and recharging with R-134a at no additional charge. ^ Provide the owner with, and review the information contained in, the "Converting Your Auto Air Conditioning System to Use the New Refrigerant" brochure. (Brochure, Form GM-0011, can be ordered free of charge from GM Fulfillment HQ, Phone 1-800-269-5100). ^ Record the customer's choice on the repair order and, as with all properly completed repair orders, ask the customer to sign on the appropriate line acknowledging the repairs requested. ^ Under no circumstances should the retrofit to R-134a be performed unless the customer has had the option explained prior to repair. Once the vehicle has been retrofitted to R-134a, a significant expenditure would be incurred to go back to R-12, in the event the customer has changed his/her mind. THIS OFFER APPLIES ONLY TO VEHICLES REQUIRING A/C REFRIGERANT SYSTEM REPAIRS UNDER THE TERMS OF THE NEW VEHICLE LIMITED WARRANTY. It is not a special policy, and any existing deductibles still apply. This is simply an option being offered to the customer during the warranty period at this time. GM reserves the right to terminate this offer at any time. If the R-12 refrigerant system does not require discharging for a warranty repair, but the customer requests a retrofit to R-134a, the retrofit WOULD BE PERFORMED AT THE CUSTOMER'S EXPENSE, EVEN DURING THE WARRANTY PERIOD. 2. Customer Paid Retrofitting Costs If the customer requests a retrofit to R-134a, for a specific vehicle whose retrofit parts and procedures have been released in this bulletin, the customer would be expected to pay the costs to retrofit under the following conditions: ^ The vehicle is no longer covered by the terms of the New Vehicle Limited Warranty. ^ The vehicle is covered by warranty, but the repair covered under the warranty does not require evacuating and recharging the refrigerant system. 3. Labor Time Information For Vehicles Repaired Under Warranty: Use existing labor operations for correcting the original condition. The quantity of R-134a used should be charged to the normal labor operation (not D4500), just as if it were R-12. Use D4500, 0.3 HR., to charge for parts and labor, for all of the following items: ^ Additional time for recovery of R-12 to meet SAE standards; ^ Install high and low side service port converter fittings; ^ Add PAG or V5 retrofit oil; ^ Complete label information and install. Add 0.2 hours to D4500 for installation of the HPCOS. Use T5321, 0.3 HR., for the Pontiac Bonneville hood seal installation. ANY PARTS OR LABOR TIME OTHER THAN THOSE LISTED ABOVE SHOULD BE CHARGED TO THE REGULAR LABOR OPERATION CORRESPONDING TO THE ORIGINAL CONDITION THAT 1S BEING REPAIRED. Isolation Diodes - Replacement Information Compressor Clutch Diode HVAC: Technical Service Bulletins Isolation Diodes - Replacement Information Number: 93-163-8A Section: 8A Date: MAY 1993 Corporate Bulletin No.: 178201R ASE No.: A6 Subject: ISOLATION DIODES REPLACEMENT INFORMATION Model and Year: 1993 AND PRIOR YEAR PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-47-8A, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS PART NUMBERS HAVE BEEN REVISED. THIS WILL ALSO UPDATE CERTAIN SERVICE MANUALS. ALL COPIES OF 92-47-8A SHOULD BE DISCARDED. Many of the electrical systems on our vehicles use a diode to isolate certain circuits and protect them from voltage spikes. Some of the circuits which may use such a diode are listed below: A/C Compressor Clutch ABS/4WAL NOTE: The ABS diode on the Delco Moraine system is hidden inside of an electrical connector under the carpet at the right kick panel. Wiper Charging System (hidden in wire harness) Parking Brake (vehicles with ABS) Relays Solenoids Diesel Glow Plug Circuit Day Time Running Lights Obtaining replacement diodes can sometimes be a problem. A universal diode, that meets the specifications in the chart below, may be used for the applications listed above. Since certain diode applications have specific part numbers, always reference the applicable GM parts catalogue before installing one of the universal diodes listed in this bulletin. When installing the new diode, use the following procedures to obtain a lasting repair: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to current flow direction, remove inoperative diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is needed to attach the new diode. 4. Check current flow direction of the new diode, being sure to install the diode with correct bias. Reference the appropriate service manual wiring schematic to obtain the correct diode installation position. Reference Figure 1 for replacement diode symbols and current flow explanations. Page 7178 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 5412 For vehicles repaired under warranty, use the table. Disclaimer Engine - Shake At Low RPM & At Idle, Engine Mount Engine Mount: Customer Interest Engine - Shake At Low RPM & At Idle, Engine Mount Group Ref.: Engine Mechanical Bulletin No.: 166102 Date: November, 1993 SUBJECT: ENGINE SHAKE AT LOW SPEEDS AND AT IDLE (MOUNT NEUTRALIZATION PROCEDURE) MODELS: 1988-92 S/T TRUCKS WITH 4.3L ENGINE (RPO LB4) This bulletin is being revised to change the service parts availability information. Previous divisional publication numbers were: Chevrolet 92-353-6 GMC Truck 92-6A-158 CONDITION Owners of some 1988-92 S/T Trucks equipped with a 4.3L engine (VIN Code Z) may comment about excessive engine shake slightly above idle (800-1800 RPM). CAUSE Due to the cylinder arrangement, design, and firing order, the 4.3L engine has inherent natural vibrations. Before attempting to repair any of these disturbances, it is necessary to compare it to another known good vehicle, same model, year, etc. Some engine shake is normal. However, if the engine shake is more than normal, it may be due to powertrain mount and/or exhaust system positioning and/or movement. The following procedure addresses the condition. CORRECTION This diagnosis is designed to identify engine mount ground out. Pay special attention to engine mounts, transmission mounts, and exhaust system hangers. The vibration or ground out location must be isolated. 1. Apply parking brake. 2. Block the front wheels. 3. Place the vehicle in DRIVE (1st gear for standard transmission). 4. Bring engine rpm up to 1500-2000, listen for ground out (knocks or booming noise) and/or increased vibrations. 5. If no ground out is found, repeat step 3 with transmission in REVERSE. CAUTION: DO NOT ACCELERATE AGAINST THE BRAKES FOR LONGER THAN 15 SECONDS. CARE SHOULD BE TAKEN NOT TO OVERHEAT THE ENGINE OR TRANSMISSION. ALSO, CARE SHOULD BE TAKEN DURING DIAGNOSIS DUE TO THE FACT THAT SOME DISTURBANCES MAY BE CREATED DURING BRAKE TORQUE THAT NORMALLY DO NOT EXIST. Note: Pay special attention to engine mounts making hard contact, check for proper clearance at tangs. If ground out or crushed mounts are confirmed, replace worn or torn components as required, refer to the neutralization procedure below. To neutralize the engine and align the exhaust system properly: 1. Allow vehicle to warm up fully. Raise vehicle and support with suitable safety stands. Page 7538 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 5065 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 5273 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 5238 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 2219 Figure 1 - Typical Fan Assembly Important To maintain a balanced fan assembly, align the yellow paint mark on the fan clutch with the yellow paint mark on the water pump hub (Figure 1.) Page 4635 Brake Bleeding: Service and Repair Master Cylinder Bleeding THIS PROCEDURE CAN BE PERFORMED WITH MASTER CYLINDER ON OR OFF VEHICLE. 1. Disconnect brake lines at master cylinder, if necessary. 2. Connect suitable lengths of brake lines to master cylinder and immerse other ends of lines in master cylinder reservoirs. 3. Apply master cylinder pushrod or brake pedal with full strokes until air bubbles have disappeared in reservoirs. It may require 20-30 applications to fully eliminate air bubbles. 4. Remove bleeding lines from master cylinder, then install master cylinder on vehicle, if necessary, and connect brake lines. 5. Fill the reservoir. Normal bleeding procedures should be followed after the master cylinder is installed. For additional information see Bench Bleeding Notes. See: Hydraulic System/Brake Master Cylinder/Fundamentals and Basics Page 2649 Disclaimer Fuel - Top Tier Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel - Top Tier Detergent Gasoline Information Bulletin No.: 04-06-00-047 Date: June 24, 2004 ADVANCED SERVICE INFORMATION Subject: Top Tier Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) Models: 2005 and Prior All General Motors Passenger Cars and Trucks (U.S. Only) A new class of gasoline, called Top Tier Detergent Gasoline, will be appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by four automotive companies. A description of the concept and benefits of Top Tier is provided in the following question and answer section. What is Top Tier Detergent Gasoline? Top Tier Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by four automotive companies that exceed the detergent requirements imposed by the EPA. Who developed Top Tier Detergent Gasoline standards? Top Tier Detergent Gasoline standards were developed by four automotive companies: BMW, General Motors, Honda and Toyota. Why was Top Tier Detergent Gasoline developed? Top Tier Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet Top Tier Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, Top Tier was developed to give fuel marketers the opportunity to differentiate their product. Why did the four automotive companies join together to develop Top Tier? All four corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of Top Tier Detergent Gasoline? Top Tier Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of Top Tier Detergent Gasoline will help reduce deposit related concerns. Who should use Top Tier Detergent Gasoline? All vehicles will benefit from using Top Tier Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from use of Top Tier Detergent Gasoline. Where can Top Tier Detergent Gasoline be purchased? The Top Tier program began on May 3, 2004. Some fuel marketers have already joined and are making plans to introduce Top Tier Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, a list of all fuel marketers meeting Top Tier standards will be made available. For now, look for the "Top Tier" designation at the gas pump. Disclaimer Page 6943 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Page 7732 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 154 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 560 Door Switch: Locations Door Jamb Switch, LH Rear In LH B-Pillar Page 1894 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 5670 Steering Gear: Service and Repair Saginaw Rack & Pinion Gear Service Service Precautions To prevent damage to the rack and pinion boot seal during removal, the following should be noted. Slide the small end of the boot toward the rack until the groove is exposed. Place a small rubber band in the groove, then slide the small end of the boot over the rubber band and off the threaded end of the tie rod. Lip seals, which seal rotating shafts, require special treatment. This type of seal is used on the steering gear at the pinion shaft and on the pump drive shaft. When a leak occurs in these areas, always inspect and thoroughly clean sealing surface before replacing. Replace seals only if severe pitting is found. If lip seal contact zone corrosion is slight, clean the surface of the shaft with crocus cloth. Replace only if the leakage cannot be stopped by smoothing with crocus cloth first. Removal/Installation 1. On models equipped with power steering, disconnect pressure and return hoses from steering gear housing, then plug hose ends and gear housing ports to prevent entry of dirt. 2. On all models, disconnect battery ground cable and remove coupling shield if so equipped. 3. Remove retaining nuts, lock washers and bolts at steering coupling to steering shaft flange. 4. Remove pitman arm nut and washer from pitman shaft and mark relation of arm position to shaft, then remove pitman arm using a puller. 5. On turbocharged models, raise and support vehicle. 6. Remove charge air cooler radiator. 7. Lower vehicle, then remove intermediate shaft assembly at steering gear. 8. Remove attaching bolt and nut to pot joint coupling. Ensure alignment marks line up. 9. On all models, remove screws securing steering gear to frame and remove gear from vehicle. 10. Reverse procedure to install. Inner Tie Rod Fig. 4 Inner tie rod removal Removal 1. Remove outer tie rod and hex jam nut from inner tie rod. 2. Remove tie rod end clamp and boot clamp. 3. Mark location of breather tube on housing, then remove boot and breather tube. 4. Disconnect shock dampener from inner tie rod and slide back on rack. 5. Secure rack assembly and remove tie rod assembly as follows: a. Place wrench on flat of rack assembly, Fig. 4. b. Place wrench on flats of tie rod housing. c. Rotate housing counterclockwise until tie rod separates from rack. Locations Dome Lamp Relay: Locations Part Of Rear Dome Lamp Assembly Page 1331 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 4789 Brake Master Cylinder: Testing and Inspection INSPECTION Inspect for Leakage NOTE: The master-cylinder should be cleaned thoroughly prior to inspection (several days preferably). Spilled brake fluid can be easily confused with leakage. Piston Seals Leakage around the piston seals will seep out from the end of the cylinder and leak down the outside of the brake booster. - Inspect for signs of seepage or bubbled paint on the brake booster. - If any leakage is detected the master-cylinder should be replaced or overhauled Brake Line Fittings While someone is applying pressure to the brake pedal, inspect the brake line fittings on the master-cylinder for leakage. - If the fittings are leaking they should be disassembled and inspected. Reservoir to Cylinder Gasket Inspect the gasket for signs of leakage or hardening and cracking. Overhaul or replace the master-cylinder if any leakage is indicated. Inspect for Oil Contamination. - Inspect the rubber gasket on the inside of the master-cylinder lid. If the gasket is swollen or bloated, the brake fluid is contaminated with oil. - Siphon or scoop a small amount of brake fluid out of the master-cylinder and place into a styrofoam cup filled 2/3 of the way with water. Brake fluid will mix with the water while oil contaminants will float on the surface and dissolve the styrofoam. NOTE: If any oil contamination is present ALL brake components containing rubber seals will need to be replaced or overhauled. This includes the master-cylinder, both front calipers, both rear wheel cylinders, and all flexible brake hoses. Verify Hold-Down Bolts Are Tight - While someone is applying and releasing pressure to the brake pedal, verify the the master-cylinder is tightly secured to the brake booster. Retighten hold-down bolts if necessary. Functional Checks WARNING: Always bleed the entire brake system and verify the rear brakes are properly adjusted prior to diagnosing a master-cylinder as defective. For additional information on master-cylinder / brake pedal relationship see Fundamentals and Basics. See: Fundamentals and Basics Check Related Systems - Check for proper brake booster operation 1. With the engine "OFF", depress and release the brake pedal 4-5 times (this bleeds off the vacuum reserve in the booster). 2. Depress the brake pedal firmly and start the engine. If the pedal goes down slightly the brake booster is assisting in brake operation. If the pedal does not go down slightly the brake booster is not assisting in brake operation and should be diagnosed for problems. - Check and adjust rear brakes. - Check all brake lines and brake assemblies for leakage. Repair all deficiencies with related systems prior to diagnosing the master-cylinder as defective. Check Brake Pedal Travel (Non-Antilock Brake Systems Only) Fully depress the brake pedal and check for the following: The pedal should have a 75% reserve. Temperature Cable Adjustment Air Door Cable: Adjustments Temperature Cable Adjustment Control Cable ADJUST 1. Remove the instrument panel storage compartment. 2. Remove the retainer from the lever. 3. Remove the cable, 4. Bend the cable to lengthen or shorten. 5. Reattach the cable to the lever and move the temperature lever In the full range of its travel and listen for the temperature door opening and closing. Adjust the cable as necessary. 6. Install the retainer. 7. Install the Instrument panel storage compartment. Page 6735 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 8203 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7454 Symbol Identification Page 4653 This results in the piston seals again being dragged across the layer of corrosion and deposits. Calipers which are not rebuilt or replaced have a higher probability of sticking or leaking. - Check to ensure the bleeder screw is not frozen prior to reinstalling caliper. Freeing a stuck bleeder screw is much easier with the caliper removed from the vehicle. Page 4314 Pinion Gear: Adjustments Dana/Spicer Fig. 5 Pinion setting chart If original ring gear and pinion assembly are to be reused, measure original shim pack and build a new shim pack to the same dimension. If baffle is in the axle assembly, it is considered part of the shim pack. Ring gears and pinions are supplied in matched sets only. If a new gear is being used, verify numbers on pinion and ring gear before proceeding with assembly. On the button end of the pinion there is a ``+'', `` - '', or ``0'' number which indicates the best running position for each particular gear set. This position is controlled by shims installed behind the inner bearing cup. If baffles or oil slingers are used, they are considered part of the adjusting shim pack. If a new gear set is being installed, note the plus or minus mark on both old and new pinions and adjust thickness of shim pack to compensate for the difference between these two numbers. Refer to chart, Fig. 5, when determining shim size. 1. Install inner shim pack and, on 9-3/4 inch ring gear axle, the oil slinger in inner or rear cup bore, then drive cup into position using suitable tool. 2. Add or remove an equal amount to the outer shim pack as was added to the inner shim pack. 3. Drive outer cup into carrier bore, then press rear pinion bearing onto pinion shaft. 4. Install drive pinion and bearing into differential carrier. 5. Install shims and outer or front pinion bearing. 6. Install companion flange, then the washer and nut on pinion shaft. Torque nut to 250 ft. lbs. with a suitable holding bar in place. 7. Remove holding bar, then measure rotating torque of pinion shaft. Rotating torque should measure 10-20 inch lbs. with original bearings installed, or 20-40 inch lbs. with new bearings installed, discounting torque required to start turning shaft. 8. If rotating torque is not within specifications, adjust shim pack as necessary. Increase outer shim pack to reduce torque, or decrease shim pack to increase torque. 9. Remove nut, washer and companion flange from pinion shaft. 10. Install oil slinger, gasket (if equipped) and oil seal onto pinion shaft. 11. Install companion flange, washer and nut and torque nut to 250 ft. lbs. Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Page 8412 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 6158 2. Remove rotor and bearing assembly retaining ring, using Snap Ring Pliers J 6083 (Fig. 9). 3. Install Pulley Rotor and Puller Guide 3 25031 to the front head (Fig. 15), and install 3 33020 Pulley Rotor and Bearing Puller down into the inner circle of slots in the rotor (Fig. 16). Turn the J 33020 puller clockwise in the slots to engage the puller tangs with the segments between the slots in the rotor. Page 312 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 1619 To eliminate the noise, use the appropriate procedure below. In determining which procedure is appropriate, inspect the engine identification number stamped on the engine block. The attached diagrams show the location of the engine identification number on the block. Use Procedure 1 for engines with a "W" in the source code location (first position). Use Procedure 2 for engines with a "T" in the source code location. Procedure 1 For LB4 engines with a "W" in the source code location. These engines have pressed-in studs and an adjustable lash valvetrain. Unlash all intake and exhaust valves. Using the valve lash procedure outlined in the service manual, lash the valves in 1.75 turns down from zero lash (not 1 turn). Procedure 2 For L35 engines or LB4 engines with a "T" in the source code location. These engines have screw-in studs and a net lash valvetrain. Remove old rocker arm nuts, rocker arms, rocker balls, and studs from the cylinder head and discard. Install adjustable lash service studs P/N 476530. Page 6717 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Page 1223 Refrigerant: Service Precautions WARNINGS: - Air conditioning systems contain Refrigerant-12. This is a special mixture which requires special handling procedures to avoid personal injury. - Always wear goggles and wrap a clean cloth around fittings, valves, and connections when performing work that involves opening the refrigerant system. - Always work in a well ventilated area and avoid breathing any refrigerant fumes. - Do not weld or steam clean on or near any vehicle-installed air conditioning lines or components. - If Refrigerant-12 should come in contact with any part of the body, flush the exposed area with water and immediately seek medical help. CAUTIONS: - All Refrigerant-12 drums are shipped with a heavy metal screw cap. The purpose of the cap is to protect the valve and safety plug from damage. It is good practice to replace the cap after each use of the drum. - If it is necessary to transport or carry any container of Refrigerant-12 in a vehicle, do not carry it in the passenger compartment. - See the manufacturer's guide-lines for storage, transportation and the maximum temperature to which the container can be exposed. - If the occasion ever arises to fill a small Refrigerant-12 drum from a large one, never fill the drum completely. Space should always be allowed above the liquid for expansion. Page 6665 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7680 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 826 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 7728 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 4589 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7182 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 3399 Page 824 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Page 7630 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Locations Fog Lamp Switch And Relay Wiring Exhaust Gas Recirculation (EGR) Valve Linear EGR Valve Central MFI Page 7278 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 3743 [243] TCC chuggle. MODEL 2DDM TRANSMISSIONS - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED BCC: DG5F) NEED TO REPLACE IT WITH P/N 8650935. [244] TCC chuggle. MODEL 2DDM TRANSMISSIONS - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED BCC: DG5F) NEED TO REPLACE IT WITH P/N 8650935. [245] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. [246] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. [247] Check engine light comes on while idling on vehicles equipped with Computer Controlled Emission System (C.C.E.S.), driven in altitudes above 3000 feet. [248] Engine may stop running during parking maneuver or during coast down at low speeds during ambient temperature above 85°F. [249] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. [250] Surge on acceleration and/or at road load speeds, false "Service Engine Soon" light (CODE 32), poor driveability during warm up, Detonation under load. Page 261 Wheel Speed Sensor: Service and Repair Rear Wheel Speed Sensor Fig. 58 Rear Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Remove brake drum. 3. Remove primary brake shoe. 4. Disconnect sensor electrical connector. 5. Remove sensor wire from rear axle clip. 6. Remove speed sensor attaching bolts, Fig. 58, then remove sensor by pulling wire through hole in backing plate. 7. Reverse procedure to install. Torque speed sensor attaching bolts to 26 ft. lbs. Page 1473 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Page 7564 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Locations Fog Lamp Switch And Relay Wiring Page 6130 Compressor Clutch: Specifications With V5 Compressor Clutch Plate & Rotor Air Gap ................................................................................................................................................ 0.50-0.076mm (0.20-0.030") Specifications Turbocharger: Specifications Turbocharger Coolant Feed Pipe 26 ft.lb Turbocharger Coolant Return Pipe Fitting 16 ft.lb Turbocharger Mounting Nut 33 ft.lb Turbocharger Oil Feed Hose Fitting 16 ft.lb Turbocharger Oil Return Pipe 5 ft.lb Turbocharger Outlet Pipe Nut 41 ft.lb Turbocharger Outlet Pipe Support Bolt 22 ft.lb Recall 99V193000: ABS 4WD Switch Defective 4WD Switch: All Technical Service Bulletins Recall 99V193000: ABS 4WD Switch Defective Description: Certain 4-wheel drive pickup trucks and sport utility vehicles equipped with ABS (antilock braking system) manufactured from September 1989 through August 1996. Under certain driving conditions the switch which signals the ABS system whether the vehicle is in 2-wheel or 4-wheel drive can malfunction causing increased stopping distances during ABS stops while in the two-wheel drive mode. If this occurred at a time when minimum stopping distance was required, a vehicle crash could occur without prior warning. Dealers will replace or repair the 4-wheel/2-wheel drive switch. The first phase of owner notification letters began May 31, 2000, with the last mailing completed by October 2000. Owners can contact Chevrolet at 1-800-222-1020 or GMC at 1-800-462-8782. Also contact the National Highway Traffic Safety Administration's Auto Safety Hotline at 1-888-DASH-2-DOT (1-888-327-4236). Page 2357 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature (ECT) Sensor Engine Coolant Temperature (ECT) W Engine Wiring, RH Side Windshield/A Pillar - Pop Noise Diagnosis Dashboard / Instrument Panel: All Technical Service Bulletins Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood A/T - Early Converter Clutch Engagement Torque Converter Clutch: Customer Interest A/T - Early Converter Clutch Engagement Number: 92-75-7A Section: 7A Date: JAN. 1992 Corporate Bulletin No.: 137107 ASE No.: A2 Subject: EARLY TRANSMISSION CONVERTER CLUTCH APPLY Model and Year: 1992 S/T TRUCKS WITH 4.3L ENGINE AND 4L60 AUTOMATIC TRANSMISSION Condition: Some owners of 1992 S/T trucks with 4.3L (LB4) engines and automatic transmissions may comment on early transmission converter clutch (TCC) engagement, TCC engagement just after the 2-3 upshift, or lack of power. Cause: The torque converter clutch is applied at low speeds during some driving conditions. Correction: To correct this condition install a new calibration PROM which raises the TCC apply speed. This calibration will increase the TCC apply speed on a 1992 vehicle to be similar to a 1991 vehicle. (See below) Part PROM Scanner Number Application Broadcast I.D. 16175285 Federal BARL 5551 16175286 California BARM 5561 Parts are expected to be available on January 27, 1992. In case of limited inventory, parts will be placed on 400 Control to waive VIP surcharges. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation at dealer's expense and all other order types will be placed on backorder until the 400 control is removed. Labor Operation Number: T0500 Labor Time: 0.8 Hour Page 1834 accumulating at least 200 miles, call the appropriate marketing division technical assistance group. CORRECTION - CATEGORY B: Valve Train Chatter, Tick, or Click. For 1992 or 1993 vehicles equipped with a Romulus built (adjustable lash) LB4 (VIN Z 4.3L V6) engine, adjust valve lash. Bulletin 376107 provides information on this procedure and on how to identify Romulus-produced engines. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts are expected to be available on August 30, 1993. WARRANTY INFORMATION: Labor Operation: J0950 - Filter and Oil Replace Labor Time: Use published labor time. For 1992 LB4 vehicles: Labor Operation: T0500 - PROM replace Labor Time: 0.5 hours Page 8105 Symbol Identification Page 725 Knock Sensor: Description and Operation Electronic Spark Control Circuit Knock Sensor (KS) Sensor PURPOSE Varying octane levels in today's gasoline can cause detonation (also known as spark knock) in an engine. The Knock Sensor (KS) system has various knock sensors that are used on all engines except the 2.5L. The KS system reduces spark knock (detonation) in the engine. This allows the engine to have a maximum spark advance for improved driveablity and fuel economy. CONSTRUCTION This KS system has three main components: - KS Module. - Knock sensor - ECM OPERATION The knock sensor detects abnormal vibration (spark knocking) in the engine. The knock sensor is mounted in the engine block near the cylinders. The KS module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the Ignition Control (IC) to reduce spark knocking. The KS module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the knock sensor. This allows the ECM to maintain maximum timing advance under various engine load conditions. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards IC to reduce spark knock. Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: All Technical Service Bulletins Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Page 562 Door Switch: Locations RH Rear Door Jamb Switch In RH B-Pillar Page 4097 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 1244 Brake Bleeding: Service and Repair Master Cylinder Bleeding THIS PROCEDURE CAN BE PERFORMED WITH MASTER CYLINDER ON OR OFF VEHICLE. 1. Disconnect brake lines at master cylinder, if necessary. 2. Connect suitable lengths of brake lines to master cylinder and immerse other ends of lines in master cylinder reservoirs. 3. Apply master cylinder pushrod or brake pedal with full strokes until air bubbles have disappeared in reservoirs. It may require 20-30 applications to fully eliminate air bubbles. 4. Remove bleeding lines from master cylinder, then install master cylinder on vehicle, if necessary, and connect brake lines. 5. Fill the reservoir. Normal bleeding procedures should be followed after the master cylinder is installed. For additional information see Bench Bleeding Notes. See: Brakes and Traction Control/Hydraulic System/Brake Master Cylinder/Fundamentals and Basics Windshield - Two-Part Urethane Adhesive For Installation Windshield: All Technical Service Bulletins Windshield - Two-Part Urethane Adhesive For Installation File In Section: 10 - Body Bulletin No.: 73-10-54 Date: May, 1997 INFORMATION Subject: Two-Part Urethane Adhesive For Windshield Installations Models: 1997 And Prior Passenger Cars and Trucks (Using Urethane Adhesive To Retain Windshields) General Motors passenger cars and trucks use urethane adhesive as a means to retain the windshield in the body opening. The urethane adhesive is used to bond the windshield in the opening, increasing vehicle structure. The current recommended urethane adhesive, GM P/N 12346284, is a one-part moisture cure product that requires a minimum curing period of 6 hours at room temperature before returning the vehicle to the customer. Increasing customer demands for faster service in recent years have resulted in quicker cure two-part urethane adhesives. Essex Beta Seal U216* (two-part urethane adhesive) meets the General Motors 3651M Specification (Performance Requirements for Stationary Glass Bonding Adhesive System Service) and can be used when the customer demands quicker repair of the vehicle than the current one-part materials can provide. Either of these products can be used when glass replacement is performed. The differences between these products are as follows: The CURRENT URETHANE ADHESIVE KIT, GM P/N 12346284, IS A ONE-PART ADHESIVE. It includes the necessary glass and pinchweld primers and is specified in Service Manuals for General Motors' vehicles. Since this is a "moisture cure" product, the curing time for this one-part material will vary with changes to either temperature or humidity. The REQUIRED TIME FOR THIS ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. ESSEX BETA SEAL U216 IS A TWO-PART ADHESIVE MATERIAL THAT PROVIDES FOR A ONE (1) TO ONE AND ONE HALF (11/2) HOUR CURE BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This product also requires primers on the glass and pinchweld surfaces. This product requires a special applicator for the mixing and dispensing of the adhesive. When using this (or any) product, make sure to follow the manufacturer's directions for application and drying times. Parts Information Parts are currently available from GMSPO. * We believe this source and their product to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. Page 7455 Symbol Identification Page 1410 Light Duty truck tire rotation recommendations are pictured on the following page. Rotation Guidelines for Tires used on Light Duty Trucks: Tires used on Pickups, Vans and Utility vehicles should be rotated at the first 6,000 miles for Schedule 1 or 7,500 miles for Schedule 2 and then every 15,000 miles thereafter. NOTE: Earlier rotation may be required should irregular wear pafterns develop due to harsh service use - the following rotation patterns are recommended for the various vehicle types and tire combinations. Page 76 Cruise Controller: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Adjustments Idle Speed Control Motor: Adjustments Base Idle Speed is not adjustable on this engine and is controlled by the control module. Refer to FUEL SUPPLY AND AIR INDUCTION/ADJUSTMENT PROCEDURES for adjusting Controlled Idle Speed. Page 1110 Fluid - Differential: Fluid Type Specifications Locking Differential (G80) This Article has been updated by TSB # 76-02-02A. SAE 80W-90 GL5 Gear Lubricant, GM P/N 1052271. Do not use limited slip additive. Non-Locking Differential Rear Axle with Non Limited Slip or Non Locking Differentials HD-3500 Trucks (Dana 11.0 axles) Recommended Lubricant - GM P/N 12346140, SAE 75W-140 Synthetic Gear Lubricant. 1999 GMT 800 Trucks Recommended Lubricant - GM P/N 12378261, SAE 75W-90 Synthetic Axle Lubricant. All other non limited-slip or non locking differentials including B and D cars, S/T, M/L, G, P, and C/K trucks except GMT 800 trucks, and as noted above. Recommended Lubricant - GM P/N 1052271 or an SAE 80W90 GL-5 Gear Lubricant. Page 7667 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) With A-6 Compressor Compressor Clutch: Specifications With A-6 Compressor Clutch Plate Air Gap ....................................................................................................................................................... 0.56-1.34 mm (0.022-0.057 inch) Specifications Shift Solenoid: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Page 4290 Fig. 10 Pinion Straddle Bearing Removal 1. Clamp pinion assembly in vise taking care not to damage housing or gear. 2. Hold driveshaft flange with suitable tool, then remove pinion nut and washer. 3. Remove driveshaft flange from pinion shaft using suitable puller. 4. Support housing in press as shown in Fig. 9, and press pinion from housing. Do not allow pinion to drop on floor. 5. Separate pinion flange, oil seal, front bearing and bearing retainer, driving seal from housing with suitable drift. 6. Remove bearing races from housing using suitable drift and place front bearing race with bearing. 7. Press rear bearing from pinion and place bearing with race. 8. Remove straddle bearing from axle housing using suitable drift, Fig. 10. 9. Inspect components keeping all components in order, and replace as needed. Assembly & Preload Coat components with specified lubricant during assembly. If components are reused, they should be installed in original position. 1. Press rear bearing onto pinion using suitable spacers. 2. Install front and rear bearing races in housing, using suitable drivers to ensure that races are properly seated. 3. Install straddle bearing in axle housing using straddle bearing installer tool No. J-23322 or equivalent to ensure that bearing is properly seated. 4. Insert pinion through housing, install new collapsible spacer and front bearing over pinion shaft, support pinion and press front bearing onto shaft. 5. Lubricate lips of new seal with grease and install seal using suitable driver to seat seal against shoulder of housing. 6. Install driveshaft companion flange, washer and new pinion nut. 7. Clamp housing in vise, hold flange with suitable tool and torque pinion nut just until all endplay is removed. 8. Check pinion bearing preload (rotating torque) using suitable torque wrench. 9. Continue tightening pinion nut in small increments until specified preload is obtained, checking preload after each adjustment. Exceeding specified preload will collapse spacer too far to be reused. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce bearing preload. Page 1185 - Meets GM contamination sensitivity requirements - Self calibrating - Micro-processor controlled - Audio alarm alerts technician Other Refrigerant Identifiers are being advertised which may be available this A/C season. However, ONLY the Kent-Moore J 39851 R12 "Pureguard" meets General Motors' current specifications which ensure recovered refrigerant is compatible with General Motors vehicles and General Motors approved recovery systems. An R134a Pureguard Refrigerant Identifier is currently under development and is anticipated to be available in early 1995. The contamination of R134a refrigerant is not expected to be a concern until the program to retrofit R12 vehicles to R134a becomes more widely used. Future bulletins will be issued to address the recovery and disposal of contaminated refrigerant. Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Page 282 RH Front Side Of Engine. RH Side Of Engine Block Applicable to: 1991 4.3L/V6-262 Engine, Bravada Page 5306 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Oil Pressure Gauge - Incorrect or Erratic Readings Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Incorrect or Erratic Readings Number: 93-57-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268304 ASE No.: A1, A8 Subject: INCORRECT OR ERRATIC OIL PRESSURE READINGS Model and Year: 1990-93 ALL LIGHT DUTY TRUCKS Owners of some 1990 through 1993 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. Service Procedure: Check for normal causes of high oil pressure gauge readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure below. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. connect the negative battery cable. Parts Information: Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: Customer Interest Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 357 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 2947 Knock Sensor: Testing and Inspection Electronic Spark Control (ESC) Circuit Check Page 5235 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 6647 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 6285 6. Remove blower motor switch. (Figure 2) 7. Remove the 2 control base plate mounting screws. (Figure 2) 8. Remove the control baseplate. 9. Remove the 4 housing to bezel mounting screws. (Figure 3) 10. Discard the broken housing. 11. Apply a small amount of GM silicone grease, P/N 12345579, or its equivalent to areas of the new housing where the mode and temperature levers protrude through the housing slots. (Figure 3) NOTE: Do not use petroleum based lubricants. Petroleum based lubricant causes the housing material to become brittle and generate a repeat failure. 12. Reassemble using the reverse procedure. Use care when assembling the base plate to the housing and bezel. The mode control lever must be Page 5254 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 4168 Clutch Pedal Assembly: Adjustments These models are equipped with a hydraulic clutch. No adjustment of the clutch pedal or linkage is provided. Page 1325 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 8021 Wheels - Sealing Leaking Cast Aluminum Wheels: All Technical Service Bulletins Wheels - Sealing Leaking Cast Aluminum Bulletin Number: 93-3-16 Reference Number: 393504 Publish Date: 7/93 Subject: LEAKING CAST ALUMINUM WHEELS (REPAIR WITH ADHESIVE SEALANT) Models Affected: 1985-1993 ALL MODELS Should a vehicle equipped with cast aluminum wheels exhibit a slow leak due to a porous condition existing in the wheel, the wheel can be repaired by using Dow Corning Silastic 732 RTV, p/n 1052366 or equivalent, as described in the following procedure: 1. Remove tire-wheel assembly from vehicle. 2. Locate leaking area by inflating tire to 40 psi and dipping tire-wheel assembly in water bath. 3. If air bubbles are observed, mark leak area and remove tire from wheel. 4. Scuff INSIDE rim surface at leak area with # 80 grit paper and clean area with general purpose cleaner, such as 3M # 08984. 5. Apply 1/8" thick layer of adhesive/sealant to leak area on INSIDE of rim and allow six hours of drying time. 6. Mount tire on wheel, pressurizing to 40 psi and check for leaks. NOTICE: Caution must be used when mounting the tire so as not to damage the sealer. 7. Adjust tire pressure to meet placard specification. 8. Balance tire-wheel assembly, using proper coated weights. 9. Water test wheel again. 10. Reinstall tire-wheel assembly on vehicle. Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation Number: E0420 A/C - R12 or R134a Service Recommendations Technical Service Bulletin # 631209 Date: 960501 A/C - R12 or R134a Service Recommendations File In Section: 1 - HVAC Bulletin No.: 63-12-09 Date: May, 1996 INFORMATION Subject: Service Issues for Vehicles with R12 or R134a Air Conditioning Systems Models: 1988-96 Passenger Cars and Trucks R12 Service Recommendations As you know, production of R12 refrigerant ceased on December 31, 1995. Although R12 will no longer be manufactured, there is a reserve supply of R12 available. This reserve, along with strict A/C repair service adherence to proper refrigerant recycling procedures, should assure continued availability to meet consumers' needs. R12 can and should continue to be used to service vehicles built with R12 A/C systems as long as it is available. If R12 is no longer available or affordable, a system retrofit utilizing R134a is recommended. R134a IS THE ONLY SUBSTITUTE REFRIGERANT RECOMMENDED BY GM FOR USE IN GM VEHICLE A/C SYSTEMS, AND THEN ONLY AFTER FOLLOWING THE PROPER RETROFIT PROCEDURES FOR THE SPECIFIC MODEL. All new vehicle manufacturers have chosen R134a for retrofit. One of the key reasons is to protect both the service industry and consumers from the high costs that would result from purchasing equipment necessary to service multiple refrigerants. This position also reduces the threat of recycled refrigerant contamination. GM currently offers a simple, low cost R12 to R134a retrofit on many of its late model, front wheel drive passenger cars. Dealers should discuss this capability with owners of these specific models, listed in Retrofit Corporate Bulletin # 43-12-07D, whenever a repair to the A/C refrigerant system is required. Early retrofit of these specific models will aid in prolonging availability of the R12 supply and provide dealer service technicians the opportunity to become more familiar with the proper procedures for performing a retrofit. Remember - R12 and R134a refrigerant are not interchangeable! They cannot be mixed together. In fact, despite the claims of some refrigerant manufacturers, no proposed R12 refrigerant substitute can be added to, mixed with or used to "top off" an R12 system. Under provisions of law covering the service of refrigerants, mixing dissimilar refrigerant products during service is prohibited. To Summarize GM R12 Service Policy 1. Service R12 vehicles with good quality new or recycled R12 as long as it is available. 2. Purchase R12 from a reliable supplier. GMSPO has a supply of high quality R12 available. Dealers are requested to use only R12 supplied by GMSPO for warranty repairs. This high quality refrigerant will insure system performance and avoid the possibility of introducing contaminated material into the customer's A/C system. 3. Carefully test recovered R12 using the PureGuard monitor. On recovery equipment not protected by the PureGuard, always test the recovery cylinder prior to recharging a vehicle A/C system. 4. Discuss the R12 to R134a retrofit option with owners of GM vehicles listed in Retrofit Corporate Bulletin # 43-12-07D. Provide owner with a copy of the pamphlet "Converting Your Auto Air Conditioning System to Use the New Refrigerant". 5. Become familiar with retrofit procedures and exercise care in the handling of dissimilar refrigerants to prevent contamination. R134A Service Recommendations When servicing a previously retrofitted vehicle, there is concern that if all of the R12 is not completely removed prior to the retrofit procedure, it could contaminate your R134a equipment and recovery tank when a subsequent A/C repair is performed. Although the number of retrofits being performed today is minimal, the volume will increase as R12 prices rise. GM Service Technology Group is in the process of field testing a new R134a refrigerant purity tester similar to the PureGuard R12 refrigerant tester you now use. This new tool will mount to your ACR4 R134a Recovery Recycle and Recharge cart and sample all R134a refrigerant prior to recovery. It is expected that testing of this tool will be completed this year. This new tool, the Pureguard 2, will also test vehicles and your recycle tank for air contamination, which is threatening A/C system performance. High levels of air have been found in the recovery tanks on a number of R12 and R134a recovery carts. Air contamination is caused by improper recovery Page 2981 Throttle Position Sensor: Service and Repair Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 2442 - Negative battery terminal. Page 3765 PROM - Programmable Read Only Memory: Service and Repair PROM 1. Remove ECM from vehicle. 2. Remove ECM access cover. PROM Removal 3. Remove PROM using the rocker-type PROM removal tool shown. Engage one end of the PROM carrier with the hook end of the tool. Press on the vertical bar end of the tool and rock the engaged end of the PROM carrier up as far as possible. Engage the opposite end of the PROM carrier in the same manner and rock this end up as far as possible. Repeat this process until the PROM carrier and PROM are free of the PROM socket. The PROM carrier with the PROM in it should lift off of the PROM socket easily. 4. Inspect the reference end of the PROM carrier and carefully set aside. Do not remove the PROM from the carrier to confirm PROM correctness. The notch in the PROM is referenced to the small notch in the carrier. The small notch of the carrier must be aligned with the small notch in the socket. CAUTION: ANY TIME THE PROM IS INSTALLED BACKWARDS AND THE IGNITION SWITCH IS TURNED ON, THE PROM IS DESTROYED. 5. Install PROM by pressing on the PROM carrier until it is firmly seated in the socket. Do not press on the PROM, only the carrier. 6. Install ECM access cover. 7. Install ECM and perform a DIAGNOSTIC CIRCUIT CHECK to confirm proper installation. Page 876 Idle Speed: Adjustments NOTE: Before performing this check: - Verify no codes displayed. - Idle air control system has been checked. - Ignition timing is correct. CONTROLLED IDLE SPEED CHECK - Set parking brake and block drive wheels. - Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. - START engine and bring it to normal operating temperature. - Check for correct state of PARK/NEUTRAL switch on SCAN tool. - Check specifications chart for controlled idle speed and IAC valve pintle position (counts). - If within specifications, the idle speed is being correctly controlled by the control module. - If not within specifications, refer to DIAGNOSIS BY SYMPTOM. See: Powertrain Management/Fuel Delivery and Air Induction/Testing and Inspection MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable on this engine. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Auto D 550 5-40 CL [1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). Page 2704 2.8L - Engine Distributor Components DELCO REMY DISTRIBUTORS Distributors with separate coils are used on light duty truck engines. The ignition coil connects to the distributor cap through a high tension wire. The distributor uses an internal magnetic pickup assembly that consists of a permanent magnet, pole piece with internal teeth, and pickup coil. When the rotating teeth of the timer core line up with the teeth of the pole piece, voltage is induced in the pickup coil. This voltage signals the ignition control module to trigger the primary ignition circuit. Current flow in the primary circuit is interrupted and a high voltage of up to 35,000 volts is induced in the ignition coil secondary winding. This high voltage is directed through the secondary ignition circuit to fire the spark plugs. The distributor used on the 2.8L engine uses a capacitor for radio noise suppression that is integral with the terminal block. IDENTIFICATION The part number (seven digits) is located on a label on the distributor cap. IGNITION CONTROL MODULE The ignition control module is a solid state unit containing many complete circuits. The circuits control spark triggering, switching, current limiting, dwell control, and distributor pickup. The vehicle's computer sends signals to the module to control dwell and spark timing. The module may have seven or eight terminals, depending on the ignition system. POLE PIECE AND COIL ASSEMBLY The pole piece and plate assembly (often referred to as the pickup coil assembly) located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. CAPACITOR The capacitor in the distributor is for radio noise suppression. Page 1162 being done. Important: During 1996, "oil-less" compressors began to be serviced with NO added oil. New part numbers will be issued, and both the box and the compressor will be clearly marked to indicate that no oil is present. If you receive one of these newer compressors, simply add the normal amount of oil to the system in Step 5 of the retrofit procedure (8 oz of PAG oil, or 9 oz of PAG oil with V5 compressor). These "oil-less" compressors are compatible with EITHER R12 or R-134a. Geo Models Compressors DO NOT HAVE TO BE REPLACED as part of the retrofit. New compressors are shipped with enough oil to accommodate the entire A/C system. Do not add additional PAG oil to the system it the compressor is being replaced. 1985-88 Nova, 1989-93 Prizm (S) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Loosen evaporator to compressor (suction) pipe (to be reinstalled) c. 1985-92 only: Loosen compressor to condenser (compressor discharge) pipe (to be reinstalled). d. 1985-88 only: Service Valve & Extension Housing on compressor (to be installed). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. 1985-88 only: Service Valve & Extension Housing on compressor using new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe 0-ring. e. 1985-92 Compressor to condenser (discharge) hose 0-ring. f. Receiver/dryer and 0-rings. R-134a amount: 85-92 - 650 grams (1.43 lb) 93 - 700 grams (1.54 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-88 - 94855761 89-93 - 94855762 Adapter Fittings: Low Side - 94855760 High Side - 94855759 0-Rings: 85-88 Compressor - Small 0-rings (6 required) - 94857336 - Large 0-ring - 94857337 85-93 Receiver/Dryer (2) - 94845949 Electrical Specifications Throttle Position Sensor: Electrical Specifications The throttle position sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Speedometer - Registers When Vehicle is Stationary Vehicle Speed Sensor: All Technical Service Bulletins Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. Page 2233 DISCLAIMER Locations LH I/P Harness Wiring Page 6128 Compressor Clutch: Specifications With HR100T/HR110T Compressor Clutch Plate and Hub to Rotor ................................................................................................................................................ 0.5-0.76 mm (0.020-0.030") Page 7553 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 559 Door Switch: Locations Door Jamb Switch, LH Front In LH A-Pillar Wheels - Finish Damage During Off Car Balancing Wheels: All Technical Service Bulletins Wheels - Finish Damage During Off Car Balancing BULLETIN NUMBER: 93-3E-67 SECTION: 3E Wheels & Tires NUMBER: 3 CORPORATE REFERENCE NUMBER: 3935O2R DATE: June 1993 SUBJECT: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING MODELS: 1985-93 MODELS WITH ALUMINUM WHEELS Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car vehicle balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make Page 2019 1. Disconnect battery. 2. Drain coolant. 3. Remove fan shroud. 4. Remove accessory drive belt. 5. Remove fan. 6. Remove the water pump. 7. Remove crankshaft pulley and harmonic balancer. 8. Remove transmission torque converter cover. Let it lie on top of exhaust crossover pipe. 9. Drop the oil pan by leaving the rear two nuts on the crankshaft seal studs about 1/4 inch from tight. The two studs will stabilize the oil pan and the oil will not have to be drained. 10. Remove the front cover. 11. It is recommended that the engine be turned over by hand so the crankshaft and camshaft sprocket timing marks are dot to dot. 12. Loosen the small diameter balance shaft gear bolt. This is the driven gear and has a TORX drive bolt. 13. Remove the camshaft sprocket by taking off the lock nut first, then the two bolts. 14. Remove the large diameter balance shaft (drive) gear. 15. Remove the small diameter balance shaft driven gear. 16. Clean all sealing surfaces, removing all old gasket material. Installation of new matched set balance shaft gears: 1. Install driven gear (small diameter gear) and bolt finger tight. 2. Install and align drive gear dot to dot with timing mark of the driven gear. 3. Install drive gear stud to 16 Nm (12 lb.ft.) to ensure the shoulder of the stud is below the counter bore in the gear. 4. Install camshaft sprocket and chain. Ensure their timing is correct. If the camshaft and crankshaft have not been disturbed, the crankshaft and camshaft sprockets should be dot to dot. 5. Install the camshaft sprocket nut and bolts. Torque to 28 Nm (21 lb.ft.). 6. Torque driven balance shaft gear bolt to 20 Nm (15 lb.ft.) plus an additional 35° using a J 3660 degree meter, torque driver. 7. At this point, the gear change is complete. Follow the removal steps in reverse order to install the remaining components. Consult the service manual for torque specifications. CORRECTION II. The following steps should be followed to diagnose the detonation type rattle noise which occurs between 2000 - 2500 RPM under load (condition II): 1. Ensure the ESC (Electronic Spark Control) system is working properly. Refer to the ELECTRONIC SPARK CONTROL section of the LIGHT DUTY TRUCK FUEL AND EMISSIONS section of the service manual. This section includes an "ELECTRONIC SPARK CONTROL SYSTEM CHECK" with a fault tree for the 4.3L CPI engine. 2. Operate the vehicle with premium fuel. If the noise is eliminated, the noise is not coming from the balance shaft rear needle bearing. Refer to the DRIVEABILITY SYMPTOMS section of the LIGHT DUTY TRUCK FUEL AND EMISSIONS service manual. BRAVADA ONLY: Refer to Bravada service manual section 6E. 3. If the ESC system is functioning properly and the noise is still audible using premium fuel, the source of the noise is most probably the rear A/T - DEXRON(R)-VI Fluid Information Fluid - A/T: Technical Service Bulletins A/T - DEXRON(R)-VI Fluid Information INFORMATION Bulletin No.: 04-07-30-037E Date: April 07, 2011 Subject: Release of DEXRON(R)-VI Automatic Transmission Fluid (ATF) Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks 2003-2008 HUMMER H2 2006-2008 HUMMER H3 2005-2007 Saturn Relay 2005 and Prior Saturn L-Series 2005-2007 Saturn ION 2005-2008 Saturn VUE with 4T45-E 2005-2008 Saab 9-7X Except 2008 and Prior Chevrolet Aveo, Equinox Except 2006 and Prior Chevrolet Epica Except 2007 and Prior Chevrolet Optra Except 2008 and Prior Pontiac Torrent, Vibe, Wave Except 2003-2005 Saturn ION with CVT or AF23 Only Except 1991-2002 Saturn S-Series Except 2008 and Prior Saturn VUE with CVT, AF33 or 5AT (MJ7/MJ8) Transmission Only Except 2008 Saturn Astra Attention: DEXRON(R)-VI Automatic Transmission Fluid (ATF) is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids. Supercede: This bulletin is being revised to update information. Please discard Corporate Bulletin Number 04-07-30-037D (Section 07 - Transmission/Transaxle). MANUAL TRANSMISSIONS / TRANSFER CASES and POWER STEERING The content of this bulletin does not apply to manual transmissions or transfer cases. Any vehicle that previously required DEXRON(R)-III for a manual transmission or transfer case should now use P/N 88861800. This fluid is labeled Manual Transmission and Transfer Case Fluid. Some manual transmissions and transfer cases require a different fluid. Appropriate references should be checked when servicing any of these components. Power Steering Systems should now use P/N 9985010 labeled Power Steering Fluid. Consult the Parts Catalog, Owner's Manual, or Service Information (SI) for fluid recommendations. Some of our customers and/or General Motors dealerships/Saturn Retailers may have some concerns with DEXRON(R)-VI and DEXRON(R)-III Automatic Transmission Fluid (ATF) and transmission warranty claims. DEXRON(R)-VI is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids (except as noted above). Please remember that the clean oil reservoirs of the J-45096 - Flushing and Flow Tester machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI for testing, flushing or filling General Motors transmissions/transaxles (except as noted above). DEXRON(R)-VI can be used in any proportion in past model vehicles equipped with an automatic transmission/transaxle in place of DEXRON(R)-III (i.e. topping off the fluid in the event of a repair or fluid change). DEXRON(R)-VI is also compatible with any former version of DEXRON(R) for use in automatic transmissions/transaxles. DEXRON(R)-VI ATF General Motors Powertrain has upgraded to DEXRON(R)-VI ATF with the start of 2006 vehicle production. Current and prior automatic transmission models that had used DEXRON(R)-III must now only use DEXRON(R)-VI. A/C - Levers Loose or Binding Control Assembly: All Technical Service Bulletins A/C - Levers Loose or Binding Number: 92-277-1A Section: 1A Date: AUGUST 1992 Corporate Bulletin No.: 261106 ASE No.: A7 Subject: TEMPERATURE CONTROL OR HVAC LEVERS LOOSE OR BINDING Model and Year: 1986-92 S/T TRUCKS Page 2819 Idle Speed/Throttle Actuator - Electronic: Testing and Inspection Idle Air Control (IAC) System Check Page 2340 Radiator: Service and Repair Page 5395 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 2776 ECM QDR Check Procedure Page 1902 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 3318 Fuel Pump Relay: Service and Repair Relay Center 2.5L,2.8L S REMOVE/DISCONNECT - Verify that ignition switch is in the "OFF" position. - Retainer, if installed. - Electrical connector. - Fuel pump relay by depressing bracket clip at rear of relay, or removing bolts from retaining bracket. INSTALL/DISCONNECT - Fuel pump relay. - Electrical connector. - Retainer. - Verify correct operation to confirm repair. Page 4705 Fig. 8 Adjusting Brake Shoes To Brake Drum Inside Diameter 8. Using suitable brake drum to shoe gauge, Fig. 5, measure brake drum inside diameter. Adjust brake shoes to dimension obtained on outside portion of gauge, Fig. 6. 9. Install brake drum, wheel and tire assembly. 10. If any hydraulic connections have been opened, bleed brake system. 11. Adjust parking brake. 12. Inspect all hydraulic lines and connections for leakage, and repair as necessary. 13. Check master cylinder fluid level and replenish as necessary. 14. Check brake pedal for proper feel and return. 15. Lower vehicle and road test. CAUTION: Do not severely apply brakes immediately after installation of new brake linings or permanent damage may occur to linings, and/or brake drums may become scored. Brakes must be used moderately during first several hundred miles of operation to ensure proper burnishing of linings. Page 273 Coolant Temperature Sensor/Switch (For Computer): Description and Operation ECT Circuit (Typical) Engine Coolant Temperature Sensor PURPOSE Engine Coolant Temperature (ECT) Sensor is used to control: Exhaust Gas Recirculation (EGR) - Fuel delivery - Idle Air Control (IAC) - Ignition Control (IC) - Torque Converter Clutch (TCC) OPERATION The ECT sensor is a thermistor that is located in the engine coolant flow. Low coolant temperature sensor produces a high resistance (100,000 ohms at -40°C/-40°F). High coolant temperature, produces a low resistance (70 ohms at 130°C/266°F). The control module sends a 5.0 volt signal to the ECT through a resistor in the control module and measures the voltage. The voltage will be high when the engine is cold and low when the engine is hot. Engine coolant temperature affects most systems controlled by the control module. The control module uses information from the ECT to calculate spark advance as follows: Cold engine results in more spark advance. - Hot engine results in less spark advance. Page 3481 Throttle Body: Service and Repair Throttle Body Assembly Removal and Replacement Throttle Body Assembly (Exploded View) REMOVAL: 1. Remove TBI assembly from vehicle. 2. Remove fuel meter body attaching screw assemblies. 3. Remove fuel meter body assembly. 4. Remove throttle body to fuel meter body gasket and discard. DISASSEMBLE: Remove TPS from old throttle body, for use on new throttle body. (IAC valve does not have to be removed, since a new one comes with replacement throttle body.) ASSEMBLE: Page 7361 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 2620 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Page 1577 A. Obtain a straight edge approximately 8-9 inches long and, while holding it in two hands, as shown in the attached illustration, place it on the inboard mounting surface of the wheel and try to rock it up and down. B. Repeat the above procedure on three or four different positions on the wheel inboard mounting surface. C. The outer ring of the mounting surface is normally raised above everything inside it. If a wheel mounting surface has been bent on a tire changer, it will be raised above the outer ring and the straight edge will rock on this "raised" portion. D. If a bent wheel is found, it must be replaced. Page 4750 Fig. 7 Installing boot to caliper 5. Position dust boot in caliper counterbore and install, Fig. 7. Check the boot installation to be sure the retaining ring molded into the boot is not bent and that the boot is installed below the caliper face and evenly all around. If the boot is not fully installed, dirt and moisture may enter the bore and cause corrosion. 6. Install the brake hose in the caliper using a new copper gasket. 7. Install pads and caliper assembly. Page 449 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 8296 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 224 Ignition Control Module: Service and Repair Typical Distributor Components REMOVE OR DISCONNECT NOTE It is not necessary to remove ignition distributor assembly from engine. - Distributor cap and rotor. - Connectors from module. - Two module attaching screws. - Lift module from housing and remove. INSTALL OR CONNECT NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. - Module onto housing. - Module attaching screws. Tighten to 2 Nm (18 lb.in.) - Connectors to module. - Rotor and cap. Page 746 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 7393 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 7423 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Wheels/Tires - Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Engine - Block Heater Leaks Engine Block Heater: Customer Interest Engine - Block Heater Leaks Number: 92-159-9E Section: 9E Date: APRIL 1992 Corporate Bulletin No.: 266201 ASE No.: A7 Subject: ENGINE BLOCK HEATER LEAKS Model and Year: 1976-92 LIGHT DUTY TRUCKS Some owners of 1976-1992 light duty truck engines may experience a leaking condition from the engine block heater. This condition may be caused by the block heater losing torque because the yoke, which secures the block heater, has cracked. This could cause a loss of engine coolant. The block heater brass yoke may crack due to stress corrosion where it contacts the stainless steel crossbar. The yoke is stressed or cracked from over torquing the hold down screw (Figure 1, "6"). Corrosion in the stressed area is accelerated due to the dissimilar metals. To correct this condition, a redesigned block heater should be installed. The yoke material (Figure 1 "3") of the block heater was changed from brass to stainless steel. The stainless steel is a higher strength material which reduces the possibility of stress corrosion and galvanic potential. SERVICE PROCEDURE: Follow the "ENGINE BLOCK HEATER REPLACEMENT" instructions in section 9E ENGINE BLOCK HEATER of the appropriate Service Manual. CAUTION: The gasket "O" ring seals between the block heater and the block. Excessive tightening is not necessary. The torque specification is 1.6 - 2.2 N-m (15.0 - 20.0 lbs.in.) The revised engine block heater (P/N 10154624) can be used in any light duty truck, gas or diesel engine, where an engine block heater is used. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION Qty/Veh 10154624 Engine Block Heater 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Body - Vehicle Glass Distortion Information Windshield: All Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 2209 Fan Blade: Testing and Inspection Place fan on flat surface with leading edge facing down. If there is a clearance between fan blade touching surface and opposite blade of more than .090 inch (2 mm), replace fan. (See caution under SERVICE PRECAUTIONS/VEHICLE DAMAGE WARNINGS). Page 7827 Fuel Gage Indicates Full Or Beyond At All Times Page 624 Engine Wiring, LH Side Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 4356 10. Lower jack and axle assembly. 11. Reverse procedure to install. Axle Shaft, Oil Seal & Bearing REAR AXLE SHAFT, OIL SEAL AND BEARING Fig. 1 Position Case For Clearance Fig. 2 Axle Shaft & Housing Components. Chevrolet Semi-Floating Axle 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove brake drum. 4. Remove carrier cover and drain fluid from axle. Remove gasket. 5. Remove locking screw. 6. Remove pinion shaft as follows: a. On models less locking differential, remove pinion shaft from case. b. On models with locking differential, remove pinion shaft partially and rotate case until pinion shaft touches the housing, Fig. 1. c. Using a screwdriver, rotate lock until it aligns with thrust block. 7. Push axle shaft flange toward differential. Do not hammer the shaft to move. 8. Remove lock (13), Fig. 2, from button end of axle shaft. 9. Slide axle shaft out from housing. Do not damage seal. 10. Using axle shaft bearing remover tool No. J-23689 or equivalent, remove oil seal. 11. Remove bearing as follows: a. Using axle shaft bearing remover tool No. J-23689 or equivalent, (for 8 1/2 ring gear), or axle shaft bearing remover tool No. J-29712 or equivalent (for 9 1/2 ring gear), carefully pull bearing from axle. b. Insert appropriate tool into axle bore so it grasps behind the bearing. Tighten nut and washer against bearing face, then pull bearing out using slide hammer with adapter tool No. J-2619-01 or equivalent. 12. Reverse procedure to install. Wheel Bearing/Oil Seal REAR WHEEL BEARING AND OIL SEAL 1. Remove axle shaft as previously described. 2. Use a suitable puller to remove bearing and oil seal. 3. Lubricate wheel bearing and cavity between seal lips with wheel bearing lubricant before installation. 4. Reverse procedure to install. Page 5104 Figure 7 Figure 8 Figure 9 Figure 10 Page 4417 Extension Housing: Specifications Warner T-5 (77MM) 5 Speed Adapter Housing Bolts ......................................................................................................................... ................................................................... 25 ft. lbs. Page 4645 Brake Caliper: Service and Repair Rebuild Caliper Assembly DISASSEMBLY 1. Remove caliper. 2. Disconnect hose from steel line, remove U-shaped retainer and withdraw hose from frame support bracket. 3. After cleaning outside of caliper, remove brake hose and discard copper gasket. 4. Drain brake fluid from caliper. Removing Piston 5. Pad caliper interior with clean shop towels and use compressed air to remove piston. Use just enough air pressure to ease piston out of bore. Do not blow piston out of bore. WARNING: Do not place fingers in front of piston in an attempt to catch or protect it when applying compressed air. This could result in serious injury. Page 6477 Vacuum Reservoir HVAC: Locations RH Side Of Engine Compartment Page 2656 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 341 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 A/C - Retrofitting R-12 to R-134a Technical Service Bulletin # 431207E Date: 970101 A/C - Retrofitting R-12 to R-134a File In Section: 1 - HVAC Bulletin No.: 43-12-07E Date: January, 1997 INFORMATION Subject: Guidelines for Retrofitting R-12 Vehicles to R-134a Models: 1984-94 Passenger Cars and Trucks (See List Below) This bulletin is being revised with the following changes: 1. Addition of all remaining GM vehicles, as listed. 2. Format rearranged for easier use. Please discard Corporate Bulletin Number 43-12-07D (Section 1 - HVAC). Car/Truck Platform Coverage Starts: 1984 - A, B, D, E, F, J, K, P, Y Carlines 1985 - C, M, N, R, S Carlines 1986 - H Carline 1987 - L, V (Allante) Car lines; M/L, G, R/V, S/T, P Truck lines 1988 - T (LeMans), E (Reatta), W Car lines; C/k, MED. Duty Truck lines 1989 - Tracker 1990 - U Van Vehicles Not Covered: T (Chevette and T1000), G RWD, C RWD, and X Car If a vehicle is not covered in the list above, GM's recommendation is that the vehicle continue to be serviced with R-12. This bulletin outlines the detailed retrofit procedures, as well as providing background information on many components and procedures. It is important to follow the bulletin, since each car and truck line has unique parts and procedures. However, the basic procedure is simple, and will become easier as you complete more retrofits. Page 7905 Malfunction Indicator Lamp: Service and Repair The Check Engine Lamp will be illuminated when the ignition switch is placed in the On position. When the engine is started, the lamp should go off. If the lamp remains on for 10 seconds or constantly after the engine is started, the self diagnosis system has detected a problem and has stored a code in the system Electronic Control Module (ECM). After diagnosis and repair, the ECM memory can be cleared of codes by removing the ECM fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the Off position. It should be noted, that if battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. Page 86 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 7208 Figure 7 Figure 8 Figure 9 Figure 10 Cruise Control - Works Intermittently Cruise Control Switch: Customer Interest Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Locations Daytime Running Lamps, I/P Wiring Page 7463 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Gauge: All Technical Service Bulletins Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 7344 Cruise Control Switch: Service and Repair Fig. 40 Mode control replacement 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect mode control connector from main harness connector and attach a suitable length of flexible wire to mode control harness. 3. Tape joint between wire and control harness to aid removal, then remove control assembly as shown in Fig. 40. 4. Reverse procedure to install. Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Page 3187 Disclaimer Page 2443 Engine Control Module: Service and Repair Engine Control Module (ECM) Replacement When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure. 1. Disconnect battery ground cable. 2. Remove right side kick panel, then disconnect two ECM electrical connectors. 3. Remove ECM mounting hardware. 4. Remove ECM from passenger compartment. 5. Reverse procedure to install. Page 1161 FOR ALL VEHICLES EXCEPT GEO, see the "Compressor Replacement Chart" at the end of this section. Compressor replacement requirements ARE NOT LISTED in the platform details (except for application details), except as noted below for Y car and P and Medium Duty truck. Compressor Replacement Chart Important: It is important to check the date code on the compressor. Any vehicle may have had a compressor replaced either during or after the warranty period. The date code will determine whether or not the compressor must be replaced. Compressor Availability A new compressor for use with R-134a systems will be shipped with the correct amount of PAG oil installed (see "IMPORTANT" below). Do not add any additional oil in Step 5 of the retrofit procedure if a compressor is to be replaced with a new R-134a compressor at the same time the initial retrofit is Page 317 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 4363 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum REAR WHEEL BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. 5. Pull hub and drum straight off axle housing. Borg Warner REAR DRIVE AXLE Fig. 1 Removing Axle Shaft. Borg Warner Axle Fig. 2 Removing Axle Shaft Bearing Retainer Nuts. Borg Warner Axle 1. Raise and support rear of vehicle, then remove wheel and tire assembly. 2. Remove brake caliper, then remove brake rotor. 3. Remove four nuts attaching axle shaft bearing retainer to axle housing. 4. Using puller and adapter J-21579 and J-2619-01 or equivalent, pull axle shaft from housing, Fig. 1. 5. To replace axle shaft bearing, split inner retainer with a suitable chisel, then remove retainer from axle shaft, Fig. 2. Using Tool No. J-22912-01 or equivalent, press bearing and seal from axle shaft. 6. Reverse procedure to install. When replacing oil seals, it should be noted right hand seal is identified by black bands, while left hand seal is identified by gold bands. Prior to installation, seal lips should be lightly coated with a suitable grease. When pressing bearing and seal onto axle Page 2556 Throttle Position Sensor: Description and Operation TP Sensor Throttle Position Sensor (TPS) PURPOSE The Throttle Position Sensor (TPS) is a non-adjustable potentiometer that senses throttle angle and relays the information to the control module. This input to the control module is used to control the fuel system and most of the control module outputs. CONSTRUCTION The TPS has internally three circuits. One to ground, the other from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage . As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). OPERATION As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation movement to the TP sensor. A potentiometer (variable resistor) within the Throttle Position (TP) sensor assembly changes its resistance in proportion to throttle movement. If the TP sensor senses a Wide Open Throttle (WOT) a voltage signal indicating this condition is sent to the control module. The control module then increases the injector base pulse width, permitting increased fuel flow. LOCATION The non-adjustable Throttle Position (TP) sensor, is mounted on the side of the throttle body opposite the throttle lever assembly. Recall 96V195000: Steering Shaft Loosening Steering Shaft: All Technical Service Bulletins Recall 96V195000: Steering Shaft Loosening The intermediate steering shaft loosens at the steering shaft to steering gear coupling. With this looseness, the yoke pinch bolt can wear on the splines of the shaft until there is no longer an interference between the splines and the bolt. This condition can cause body to chassis movement allowing the steering shaft to separate from the steering gear which can result in a loss of steering control. Dealers will retorque the upper and lower bolts to correct specifications. Vehicle Description: Postal vehicles only. Owner Notification: Owner notification is expected to begin during late October 1996. NOTE: Owners who take their vehicles to an authorized dealer on an agreed upon service date and do not receive the free remedy within a reasonable time should contact Chevrolet at 1-800-222-1020. Also contact the National Highway Traffic Safety Administrations Auto Safety Hotline at 1-800-424-9393. 1987 CHEVROLET TRUCK S10 1988 CHEVROLET TRUCK S10 1989 CHEVROLET TRUCK S10 1990 CHEVROLET TRUCK S10 1991 CHEVROLET TRUCK S10 1992 CHEVROLET TRUCK S10 1993 CHEVROLET TRUCK S10 1994 CHEVROLET TRUCK S10 1995 CHEVROLET TRUCK S10 Page 8348 Side Marker Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 6199 Installing Pulley Rotor Bearing 1. Place the pulley rotor on the J 21352-A support block to fully support the rotor hub during bearing installation. NOTICE: DO NOT support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using puller and bearing installer J 9481-A with universal handle J 29886, drive the bearing fully into the hub. The installer will apply force to the outer race of the bearing. Staking Bearing In Rotor Hub Bore 3. Place bearing staking guide J 33019-1 and bearing staking pin J 33019-2 in the hub bore. Shift the rotor and bearing assembly on the 321352-A support block to give full support of the hub under the staking pin location. A heavy duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide after each impact on the pin. 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to but not touching the bearing. Page 7683 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 4148 Clutch Master Cylinder: Service and Repair Fig. 1 Clutch Master Cylinder. REMOVAL 1. Remove sound absorbing panel from upper left side foot well. Remove lower air conditioning duct, if necessary. 2. Disconnect master cylinder push rod from clutch pedal. 3. Remove master cylinder retaining nuts. 4. Disconnect reservoir hose and slave cylinder hydraulic line from master cylinder. 5. Remove clutch master cylinder. INSTALLATION 1. Position master cylinder at front of dash, then install retaining nuts and torque to 10-15ft. lbs. 2. Connect master cylinder push rod to clutch pedal and install retaining clip. 3. Install sound absorbing panel. 4. Install lower air conditioning duct, if removed. 5. Connect reservoir hose and slave cylinder hydraulic line to master cylinder. 6. Bleed system as described under "Hydraulic Clutch System Bleed." Refer to Hydraulic Clutch System Bleed. Page 2738 Engine Wiring, LH Side Page 7815 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 2847 MAP Circuit (VCM) VCM Circuit Page 529 Fuel Gauge Sender: Testing and Inspection Diagnostic Circuit Check Page 4023 1. On vehicles equipped cruise control, remove cruise control rod. 2. On all models, disconnect TV cable from throttle assembly, then loosen locknut on pump rod and shorten several turns. 3. Turn lever assembly to full throttle stop and hold in this position. 4. Adjust pump rod until injection pump lever contacts full throttle stop. 5. Release lever assembly and tighten pump rod locknut, then remove pump rod from lever assembly. 6. Connect TV cable to throttle assembly, then depress and hold metal readjusting tab. Move slider back through fitting in direction away from lever assembly until slider stops against fitting, Fig. 7. 7. Release readjust tab, then rotate lever assembly to full throttle stop and release the lever. 8. Connect pump rod and, if equipped, the cruise control throttle rod. 9. On vehicles equipped with cruise control, adjust servo throttle rod to minimum slack position. Install clip into servo ball in first free hole closest to the bell crank. Diagram Information and Instructions Fuse Block: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 5596 Use applicable labor time guide for labor hours. Page 7051 * We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Important Additional time or payment beyond established allowances in this bulletin will not be allowed. - The use of a razor blade on large flat surfaces is not recommended because of the potential to chip. gouge or otherwise damage the primer surface. If razor blade technique is used, the application of a "guide coat" prior to wet sanding should also be used. Note: Chemical stripping is not recommended because of negative impact to moldings, non-metal components, ELPO and environmental concerns. 4. Blow off with air to remove all dirt and sanding residue from cracks and vehicle surface. 5. Clean sanded surface with an appropriate wax and grease remover. 6. Tack wipe entire area to be primed. 7. Spray entire prepared area with a coat of anti-corrosion primer to ensure maximum adhesion and corrosion resistance. Be sure to cover any bare metal surfaces exposed during the sanding operations. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 615S/616S, BASE DE17/PR8O/DA18, PPG DP4O/DP401, or equivalent. V.O.C. materials would be: DuPont 615S/616S, BASF DE15/PA16/PRB0, PPG DCP21/DCX211 or equivalent. 8. Apply two to three medium wet coats of primer surfacer to the primed surface of the vehicle, following the manufacturer's instructions for application and film build requirements. Important Failure to apply primer surfacer will likely result in future delamination. Typical materials for this application would be: DuPont 1120S/1130S/1125S, BASF DP20/PR80/PH36, PPG K36/DT870/K201, or equivalent. V.O.C. materials would be: DuPont 210S, BASF HP400, PPG DCP21/DCX211, or equivalent. 9. After allowing adequate drying time, wet sand with 400 grit (or finer) or dry sand with 320 grit (or finer) sandpaper. 10. Repeat steps 4 through 6. 11. Apply a medium coat of corrosion resistant primer sealer (tintable base) to the entire surface to be refinished. This will provide maximum adhesion, uniform color coating and corrosion protection to areas "sanded through" during wet sanding. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 2610S/2605S, BASF DP21/DH6O/PR80, PPG DP40/DP402 or equivalent. V.O.C. materials for this application would be: DuPont 21255, PPG DPW1834 or equivalent. 12. Apply two to three medium wet coats of color (or until primer color is hidden). Follow manufacturer's instructions and recommended dry times. 13. If vehicle has basecoat/clearcoat paint, apply clearcoat. Follow manufacturer's instructions and recommended dry times. 14. After sufficient air or force dry time, unmask the vehicle. 15. Finesse/polish as required. 16. Reinstall all previously removed items. 17. Wash and prepare the vehicle for delivery. HARDWARE ITEMS REMOVAL LIST Note: Some technicians may apply a small cord (wire, plastic tube, etc.) behind or underneath moldings that remain on the vehicle to improve sanding and painting. If the vehicle paint system is baked with cord in place, damage to some moldings may occur. If this technique is used, DO NOT BAKE Page 7387 Cruise Controller: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Locations Engine Wiring, LH Side Locations Underhood Lamp Wiring Page 8800 Fig. 3 Permanent Magnet Type Windshield Wiper Motor W/Pulse Wipers Front The front wiper system consists of a permanent magnet positive park pulse wiper, a washer pump mounted under the washer bottle and a turn signal type wiper/washer switch. The die cast aluminum housing of the wiper provides superior cooling of internal parts, Fig. 3. An electronic circuit board controls all the timing and washer commands. When the washer button is pushed for more than .3 seconds, a demand wash is performed in 1.5 second intervals for as long as the button is held followed by approximately 6 seconds of dry wipes and a shutoff. Turning switch to either the Lo or Hi speed position completes the circuit and runs at that speed. The pulse and demand wash functions are controlled by a plug-in printed circuit board enclosed in the wiper housing cover. Turning switch to the Pulse position operates the motor intermittently and the delay can be varied by rotating the switch. An instantaneous wipe can be obtained by rotating the switch to the Mist position and a continuous wipe will be performed if the button is held. Rear The rear wiper system consists of a permanent magnet positive park single speed wiper mounted to the rear glass. A wiper arm is mounted directly onto the wiper motor and operation is controlled by a two position dash mounted switch. The wiper/washer switch has a momentary wash and wipe position and must be turned off manually. The wiper motor is serviced as an assembly. Page 340 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 2540 Oxygen Sensor: Technical Service Bulletins Engine Controls - Heated Oxygen Sensor Diagnosis Group Ref.: Engine Fuel & Emission Bulletin No.: 366501 Date: November, 1993 INFORMATION SUBJECT: HEATED OXYGEN SENSOR DIAGNOSIS MODELS: 1992-93 CHEVROLET & GMC LIGHT DUTY TRUCKS WITH 4.3L (LB4/L35), 5.0L (L03) AND 5.7L (L05) ENGINES 1992-93 OLDSMOBILE BRAVADA Some heated oxygen sensors are being replaced in error due to low reference voltage. REFERENCING SERVICE MANUAL Before diagnosing any heated oxygen sensor, be sure to follow the appropriate service manual diagnostics. The fault tree selected is dependent upon which control module system is on the vehicle. DIAGNOSTIC INFORMATION The electronic control module (ECM) normally applies a reference voltage of approximately 450mv to the oxygen sensor. When the ignition is turned "on", the heating element inside the oxygen sensor will immediately start heating the sensor element. The oxygen sensor will become fully functional in 15 to 90 seconds. Because the engine is not running, the gases around the oxygen sensor in the exhaust stream will be mostly ambient air. The high amount of oxygen in the exhaust stream will be interpreted as a lean exhaust and the 450mv reference voltage from the ECM will be pulled low. The oxygen sensor voltage should drop from 450mv to less than 100mv within 90 seconds. Therefore, the oxygen sensor is performing normally. LOW REFERENCE VOLTAGE (This test must be completed within 10 seconds after key up.) If your Tech 1 initial reference voltage is low (less than 300mv), you may have a shorted oxygen sensor. Turn the ignition "off"; allow the sensor to cool for ten minutes and retest. If the voltage is still low, disconnect the oxygen sensor and see if your Tech I now indicates approximately 450mv reference voltage. If so, change the oxygen sensor. HIGH REFERENCE VOLTAGE If your Tech 1 initial reference voltage is high (greater than 600mv), you may have a sensor signal that is shorted to heater voltage. This may cause a code 45. Allow sensor to cool ten minutes and retest. If voltage still remains high, disconnect oxygen sensor. If reference voltage still remains high, you may have a short to voltage in the engine harness or an ECM problem. If you disconnect the oxygen sensor and reference voltage returns to approximately 450mv, replace the internally shorted oxygen sensor. Page 5259 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 3494 ACCELERATOR CONTROL CABLE When performing service on the accelerator control cable, observe the following: The retainer must be installed with the tangs secured overhead of the stud. - The conduit fitting at both ends of the cable must have the locking tangs expanded and locked in the attaching holes. - The braided portion of the accelerator cable assembly must not come in contact with the front of the dash sealer during assembly, repair, or replacement of the assembly. - The flexible components (hoses, wires, conduits, etc.) must not be routed within 50 mm (2 inches) of the moving parts of the accelerator linkage outboard of the support unless the routing is positively controlled. REMOVE/DISCONNECT - Retainer from throttle lever stud - Retainer locking tangs from support bracket - Retainer from accelerator pedal rod or release cable from rod. - Retainer locking tangs from dash panel INSTALL/CONNECT - Retainer to dash panel. - Retainer to accelerator pedal rod or connect cable in rod slot. - Retainer to support bracket. - Retainer to throttle lever stud or connect cable to pulley. Page 5173 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 5375 Fuse Block: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 8565 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 8299 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 6640 Symbol Identification Removal Brake Caliper: Service and Repair Removal For additional information see Removal Notes. See: Fundamentals and Basics 1. Siphon enough brake fluid out of the master cylinder to bring fluid level to 1/3 full to avoid fluid overflow when the caliper piston is pushed back into its bore. 2. Raise vehicle and remove front wheels. Fig. 2 Compressing piston & shoes with C-clamp 3. Using a C-clamp, push piston back into its bore. Fig. 3 Caliper & Mounting Bolts 4. Remove two mounting bolts and lift caliper away from disc. Hang caliper from coil spring with wire. CAUTION: Do not allow caliper to hang from brake hose. A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: Customer Interest A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). 4L60 & 4L60-E Transmission Transmission Speed Sensor: Specifications 4L60 & 4L60-E Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Page 4956 Neutral Safety Switch: Description and Operation Fig. 4 Mechanical Lockout. Except Tilt Column Fig. 5 Mechanical Lockout. Tilt Column Actuation of the ignition switch is prevented by a mechanical lockout system, Figs. 4 and 5, which prevents the lock cylinder from rotating when the selector lever is out of Park or Neutral. When the selector lever is in Park or Neutral, the slots in the bowl plate and the finger on the actuator rod align, allowing the finger to pass through the bowl plate in turn actuating the ignition switch. If the selector lever is in any position other than Park or Neutral, the finger contacts the bowl plate when the lock cylinder is rotated, thereby preventing full travel of the lock cylinder. Page 7069 Sherwin-Williams, Acme/Rogers, and Martin-Senour are available in acrylic lacquer, acrylic enamel, or acrylic urethane. S-W use: prefix 34, J4 or L10/L11 for acrylic lac- quer, prefix 35, J5 or F10/F11 for acrylic enamel, prefix UB for acrylic urethane in a basecoat/clearcoat system, prefix US for acrylic urethane in a sin- gle stage system. ACME use: prefix 84 for acrylic lacquer, prefix 85 for acrylic enamel, prefix PB for acrylic urethane in a basecoat/clearcoat system, prefix PS for acrylic urethane in a single stage system. Rogers Use: prefix 94 for acrylic lacquer, prefix 95 for acrylic enamel, prefix AU for acrylic urethane in a basecoat/clearcoat system, prefix AS for acrylic urethane in a single stage system. Martin-Senour: Jobber will interchange number shown when acrylic lacquer is needed, use prefix 98 for acrylic urethane as an inter-mix basecoat/clearcoat, use prefix 88 for acrylic urethane as a factory packaged basecoat/clearcoat, use prefix 97 for acrylic urethane as an inter-mix single stage system, use prefix 87 for acrylic urethane as a factory packaged single stage system. 1992 TRUCK EXTERIOR COLORS Paint BASF Glasurit Color Fisher Martin- Sherwin-Williams PPG Rinshed 54-21 Code Color Name W-Code DuPont Senour Acme-Rogers DDL-DAR Mason Line 10 Gray White 9225 B8796 36783 36783 4015* 18121 GM-9225 12 Yellow White 5111 817 82-1208 F8W-2030 2185 1347 GM-5438 1492 15 Astral Silver 8914 C8501 82-5915 34856 3796* 15251 GM-8914 16 Warm Gray Metallic B/C 9659 B9125 44149 44149 4314 21017 GM-9659 17 Lt. Slate Metallic 7468 B8235 82-5579 32377 3453 12866 GM-7023 19 Lamp Black 5118 99 8800 F10B-1738 9000/9300 Standard GM-1240 80-4080 Package 22 Bahama Blue Met. B/C 9656 B9126 44150 44150 4307 21018 GM-9656 23 Ocean Blue 7154 B8041 82-5258 30527 3250 11500 GM-5481 24 Med. Bright Blue Metallic 9222 B8894 38144 38144 4110 18120 GM-9222 25 Bright Teal 9830 B9224 45877 45877 4469 22263 GM-9830 26 Pastel Blue 9662 B9128 44151 44151 4308 21019 GM-9662 27 Lt. French Blue Metallic 9264 B8944 39337 39337 4146 19031 GM-9264 29 Dark Blue 7349 B8139 82-5448 31514 3362 12283 GM-5039 30 Gray Blue Metallic 9086 B9017 42478 42478 4238 20050 GM-9086 34 Lt. Teal Metallic 9793 B9221 45878 45878 4455 21040 GM-9793 36 Med. Dk. Teal Metallic 9828 B9222 45879 45879 4347 22073 GM-9828 37 Light Mesa Brown 9219 B8897 38147 38147 4111 18118 GM-9219 41 Black B/C 8555 99 82-5760 33756 9700 13572 54-1240 43 Seafoam Green 9663 B9129 44152 44152 4309 21020 GM-9663 46 Dark Green 7156 B8046 82-5263 30530 3255 11505 GM-5482 47 Dark Blue Metallic 9095 B9019 42479 42479 4251 20052 GM-9095 48 Dark Red 9096 B9020 42480 42480 4239 20053 GM-9096 50 Blue White 8624 B8550 82-5918 34851 3800 15255 GM-8624 51 Sedona Tan 8528 B8542 90-5857 34392 4310 15022 GM-8528 54 Dk. Green Blue Metallic 9831 B9225 45913 45913 45DO 22267 GM-9831 57 Beige Metallic 5400 B9213 45881 45881 4346 22271 GM-5400 61 Tan 8265 B8462 82-5799 34070 3686 14241 GM-1074 71 Red Orange 7753 B8250 82-5586 32384 3463 12884 GM-3046 72 Standard Red 7475 B8241 82-5539 32097 3464 12885 GM-3047 74 Victory Red 9260 B8946 39339 39339 4154 19030 GM-9260 75 Red Metallic B/C 8919 C8506 82-5945 34855 3804* 15259 GM-89191 76 Dk. Garnet Red Met. B/C 9154 B8742 36454 36454 4002* 21023 GM-9154 78 Dark Yellow Red Metallic 8800 B8632 90-6069 35366 3915 16117 GM-3091 90 Gray Metallic 8798 B8629 82-6011 35367 3916 16118 GM-8798 Page 6427 f. TO INSURE AN ACCURATE CHARGE AMOUNT, IT IS IMPORTANT TO CLEAR THE ACR4 OF ANY REMAINING REFRIGERANT. Close the high side coupler valve and remove the high side hose from the vehicle. Then, open both the high and low side valves on the ACR4. After the pressures on both gages are at low side pressure, close the low side coupler valve. See Step G below, then remove the low side hose from the vehicle. Shut off the engine. Install the service port caps on the new fittings. These serve as a seal and can prevent system leaks. g. In the unlikely event that the low side fitting leaks when the coupler is removed, use the following procedure: 1. Immediately reinstall the coupler on the fitting. 2. Find the valve core remover J 34611-A. 3. Remove the coupler. 4. Use the double-ended valve core remover to turn the valve core pin counter-clockwise until the leak stops. 5. Install the cap. If the leak was substantial or continued for an extended period of time, it is highly recommended to evacuate and recharge the system to insure proper performance. If there is any question, the system can be rechecked by repeating Step F. h. Leak test any new port fittings, adapters, or valves that were installed, and any joints that were opened or repaired during the retrofit process, using tool J 39400. 6. Install the Retrofit Label The retrofit label (P/N 21030857, roll of 250) has been developed following SAF specifications to insure a smooth transition from R-12 to R-134a, and to insure a professional approach to the retrofit and a quality repair. Following the instructions in this bulletin will insure that the retrofit meets the SAE standards. Fill in the new label using a typewriter or a ball-point pen (see Figure 6). Select a location for the label that will be easily visible. Some suggested areas are the radiator support panel, an area near the existing R-12 charge label, or a flat surface near the high or low side service ports. The area selected should be a clean, underhood, painted sheet metal surface, and should be degreased and wiped down with a non-petroleum based cleaner. Do not install the label on a rubber surface. Apply the label, then apply the clear overlay to the label. Do not remove, cover, or render unreadable the existing R-12 charge label. DO cover the R-12 refrigerant charge amount on the existing label with an indelible, preferably black, marker. Platform Details Two Wheel Drive - 2WD Wheel Bearing: Adjustments Two Wheel Drive - 2WD FRONT WHEEL BEARINGS ADJUSTMENT 4 X 2 MODELS 1. Raise and support front of vehicle. 2. Remove hub dust cover, then the cotter pin. 3. While rotating wheel assembly in forward direction, torque spindle nut to specification to fully seat the bearings. 4. Loosen nut to the ``just loose'' position, then tighten the spindle nut finger tight. 5. If either spindle hole does not line up with a spindle nut slot, back off spindle nut not more than 1/2 nut flat. 6. Install new cotter pin, then measure hub endplay. Endplay should be .001-.005 inches when properly adjusted. 7. Install hub dust cover and lower vehicle. 4 X 4 MODELS These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Page 3701 accumulating at least 200 miles, call the appropriate marketing division technical assistance group. CORRECTION - CATEGORY B: Valve Train Chatter, Tick, or Click. For 1992 or 1993 vehicles equipped with a Romulus built (adjustable lash) LB4 (VIN Z 4.3L V6) engine, adjust valve lash. Bulletin 376107 provides information on this procedure and on how to identify Romulus-produced engines. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts are expected to be available on August 30, 1993. WARRANTY INFORMATION: Labor Operation: J0950 - Filter and Oil Replace Labor Time: Use published labor time. For 1992 LB4 vehicles: Labor Operation: T0500 - PROM replace Labor Time: 0.5 hours Page 64 Antilock Brake Module: Electrical Diagrams Fig. 7 Four Wheel Anti-lock Brake Wiring Circuit. Bravada, Astro/Safari & 2WD S/T Page 3351 Parts Information Parts are currently available from GMSPO. Locations Seat Belt Retractor: Locations On Safety Belt Assembly Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: All Technical Service Bulletins Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Restraints - Driver/Passenger Seat Head Rest Information Head Restraint System: Technical Service Bulletins Restraints - Driver/Passenger Seat Head Rest Information INFORMATION Bulletin No.: 10-08-50-003A Date: March 24, 2011 Subject: Information on Driver or Passenger Seat Head Restraint Concerns with Comfort, Custom Upholstery or Other Comfort Enhancing Devices Models: 2012 and Prior GM Passenger Cars and Trucks Equipped with Adjustable Head Restraints Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 10-08-50-003 (Section 08 - Body and Accessories). Important ON A GM VEHICLE EQUIPPED WITH ADJUSTABLE HEAD RESTRAINTS, USE THE HEAD RESTRAINT COVERS, FOAM AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER OR REPOSITION THE HEAD RESTRAINT SYSTEM. ANY ALTERATIONS TO HEAD RESTRAINTS DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER DESIGN ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. You may have a customer with a concern that the head restraint is uncomfortable or sits too far forward. The front driver and passenger seats are equipped with head restraints that have been designed to help minimize injuries while still providing comfort to the occupants. Each GM vehicle has its own specifically designed head restraint. The head restraints should only be used in the vehicle for which they were designed. The head restraint will not operate to its design intent if the original foam is replaced (1) by non-GM foam or head restraint, (2) by GM foam or head restraint designed for a different vehicle, (3) by GM foam or head restraint that has been altered by a trim shop or (4) if any object, such as an aftermarket comfort enhancing pad or device, is installed. Never modify the design of the head restraint or remove the head restraint from the vehicle as this may interfere with the operation of the seating and restraint systems and may prevent proper positioning of the passenger within the vehicle. Disclaimer Page 7170 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Diagnostic Charts Underhood Lamp Does Not Operate Page 8395 Parking Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 8571 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 8578 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 7672 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 1084 Fluid - A/T: Technical Service Bulletins A/T - Water Or Coolant Contamination Information INFORMATION Bulletin No.: 08-07-30-035B Date: November 01, 2010 Subject: Information on Water or Ethylene Glycol in Transmission Fluid Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks with Automatic Transmission Supercede: This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 08-07-30-035A (Section 07 - Transmission/Transaxle). Water or ethylene glycol in automatic transmission fluid (ATF) is harmful to internal transmission components and will have a negative effect on reliability and durability of these parts. Water or ethylene glycol in ATF will also change the friction of the clutches, frequently resulting in shudder during engagement or gear changes, especially during torque converter clutch engagement. Indications of water in the ATF may include: - ATF blowing out of the transmission vent tube. - ATF may appear cloudy or, in cases of extreme contamination, have the appearance of a strawberry milkshake. - Visible water in the oil pan. - A milky white substance inside the pan area. - Spacer plate gaskets that appear to be glued to the valve body face or case. - Spacer plate gaskets that appear to be swollen or wrinkled in areas where they are not compressed. - Rust on internal transmission iron/steel components. If water in the ATF has been found and the source of the water entry has not been identified, or if a leaking in-radiator transmission oil cooler is suspected (with no evidence of cross-contamination in the coolant recovery reservoir), a simple and quick test kit is available that detects the presence of ethylene glycol in ATF. The "Gly-Tek" test kit, available from the Nelco Company, should be obtained and the ATF tested to make an accurate decision on the need for radiator replacement. This can help to prevent customer comebacks if the in-radiator transmission oil cooler is leaking and reduce repair expenses by avoiding radiator replacement if the cooler is not leaking. These test kits can be obtained from: Nelco Company Test kits can be ordered by phone or through the website listed above. Orders are shipped standard delivery time but can be shipped on a next day delivery basis for an extra charge. One test kit will complete 10 individual fluid sample tests. For vehicles repaired under warranty, the cost of the complete test kit plus shipping charges should be divided by 10 and submitted on the warranty claim as a net item. The transmission should be repaired or replaced based on the normal cost comparison procedure. Important If water or coolant is found in the transmission, the following components MUST be replaced. - Replace all of the rubber-type seals. - Replace all of the composition-faced clutch plates and/or bands. - Replace all of the nylon parts. - Replace the torque converter. - Thoroughly clean and rebuild the transmission, using new gaskets and oil filter. Important The following steps must be completed when repairing or replacing. Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052F- Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow. - Thoroughly inspect the engine cooling system and hoses and clean/repair as necessary. M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot Clutch Disc: All Technical Service Bulletins M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot BULLETIN NUMBER: 92-7B-149A SECTION: 7B Manual Transmission NUMBER: 1 CORPORATE REFERENCE NUMBER: 2672O1R DATE: August 1993 SUBJECT: NEUTRAL GEAR RATTLE (REPLACE CLUTCH DISK, PROM AND PILOT BUSHING) MODELS: 1990-92 C/K AND 1990-92 S/T WITH 4.3L AND 5 SPEED MANUAL TRANSMISSION This bulletin cancels and replaces Truck Bulletin 92-7B-149 (corp. # 267201R) dated December 1992, and is being revised to add the 1992 model year S/T Trucks with 4.3L engines (RPO LB4) and to add the "Detonation and Neutral Gear Rattle Proms" section. CONDITION Some owners of 1990-92 C/K and 1990-92 S/T Trucks with 4.3L engines (RPO LB4) and 5-speed manual transmission (RPO's MG5, MY2) may comment that the transmission rattles when in neutral with their foot off the clutch pedal and the engine at idle. The customer may describe the rattle as loose bearings. CAUSE This rattle noise is created when the turning transmission gears contact against each other. The contact is created by the firing impulses of the engine which causes rapid acceleration and deceleration of the individual gears. CORRECTION This condition may be corrected by the installation of the following parts: - A revised clutch driven disc which features a live degree neutral stage. This neutral stage helps to smooth the rapid acceleration and deceleration of the individual transmission gears. - A revised PROM which raises engine idle speed to 650 RPM on C/K and 700 RPM on S/T. This increase in idle speed helps to smooth the engine firing pulses. - A clutch pilot bearing rather than a clutch pilot bushing. This bearing helps to isolate the transmission from the engine idle acceleration/deceleration. SERVICE PROCEDURE Important Incorrect engine idle can contribute to neutral gear rattle. Before installing the parts listed in this bulletin, refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 2, Driveability Symptoms "Rough, Unstable or Incorrect Idle Stalling" to verify there are no existing conditions contributing to a rough idle which may aggravate neutral gear rattle. Clutch Disc and Pilot Bearing Replacement: Refer to the appropriate year and model Service manual, Section 7C "Clutch Assembly and Pilot Bearing Replacement." Important C/K trucks require pressure plate P/N 15974649 which was first used in production mid-1991. 1990 and 1991 vehicles built prior to the following VIN breakpoints require installation of P/N 15974649 unless it has already been installed in a service repair: Ft. Wayne (Z) MZ516555 Oshawa (1) M1526826 Pontiac (E) ME51G465 PROM Replacement: Refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 3 "On-Vehicle Service, PROM". Page 3875 Page 3758 PROM - Programmable Read Only Memory: Description and Operation PROM CAUTION: If the computer is found to be defective and needs replacement, remove the old PROM and place it into the replacement computer. Some ECM's are equipped with another chip called a CALPAK. If the computer is equipped with a CALPAK chip, it will be located next to the PROM and must be transferred along with the PROM. When replacing the computer always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: To allow one type of computer to be used for many different vehicles, a device called a Programable Read Only Memory (PROM) unit is used. The PROM is located inside the computer and has system calibration information based upon the vehicle's axle ratio, engine, transmission, weight, and other specific configurations of the vehicle. Page 5781 Light Duty truck tire rotation recommendations are pictured on the following page. Rotation Guidelines for Tires used on Light Duty Trucks: Tires used on Pickups, Vans and Utility vehicles should be rotated at the first 6,000 miles for Schedule 1 or 7,500 miles for Schedule 2 and then every 15,000 miles thereafter. NOTE: Earlier rotation may be required should irregular wear pafterns develop due to harsh service use - the following rotation patterns are recommended for the various vehicle types and tire combinations. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 8026 Diagnostic Circuit Circuit Description The diagnostic circuit check is an organized approach to identifying a problem created by an electronic engine control system malfunction. It must be the starting point for any driveability complaint diagnosis, because it directs the service technician to the next logical step in diagnosing the complaint. Understanding the chart and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of good parts. Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. This step is a check for the proper operation of the "Service Engine Soon" light. The "SES" light should be "ON" steady. 2. No "SES" light at this point indicates that there is a problem with the "SES" light circuit or the control module control of that circuit. 3. This test checks the ability of the control module to control the "SES" light. With the diagnostic terminal grounded, the "SES" light should flash a Code 12 three times, followed by any trouble code stored in memory. A PROM error may result in the inability to flash Code 12. 4. Most of the diagnostic charts use a Tech 1 to aid diagnosis, therefore, serial data must be available. If a PROM error is present, the control module may have been able to flash Code 12 or 51, but not transmit serial data. 5. Although the control module is powered up, a "Cranks But Will Not Run" symptom could exist because of an control module or system problem. 6. This step will isolate if the customer complaint is a "SES" light or a driveability problem with no "SES" light. Refer to Computers and Control Systems for a list of valid codes. An invalid code may be the result of a faulty "Scan" tool, PROM or control module. See: Powertrain Management/Computers and Control Systems 7. Comparison of actual control system data with the typical valves is a quick check to determine if any parameter is not within limits. Keep in mind that a base engine problem (i.e., advanced cam timing) may substantially alter sensor values. 8. If the actual data is not within the typical values established, refer to Computers and Control Systems. See: Powertrain Management/Computers and Control Systems Page 7464 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 7063 Customers should be urged to wash and dry their vehicles frequently and garage them, or at least cover them with a quality car cover when not in use. Vehicles in dealer inventories should be kept clean and dry. A vehicle that sits unattended, especially after the sun has dried any water on the body surface, is a target for acid rain damage. MATERIALS DESCRIBED IN THIS BULLETIN* WAX AND GREASE REMOVER - USE BELOW OR EQUIVALENT Dupont # 3919S, PPG # DX440, BASF # 900, SIKKENS # 6041 FINESSE POLISHES - USE BELOW OR EQUIVALENT Dupont # 1500S, 3000S; BASF # 563-808, 560-1502; PPG # DRX10; 3M PERFECT-IT * USE V.O.C. EQUIVALENTS IN STATES WITH V.O.C. RESTRICTIONS RAIL DUST REMOVER - USE BELOW OR EQUIVALENT Industrial Fallout Remover # 5029 Zep Corporation Atlanta, GA. Telephone # 404-352-1680 Stain Away # HBY 0160 Hornby Chemical Milwaukee, WI. Telephone # 414-462-2833 If the rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. PAINT GAGES - USE BELOW OR EQUIVALENT Elcometer Inc. 1893 Rochester Ind. Drive Rochester Hills, MI. 48309 (800) 521-0635 or (313) 650-0500 Zelcro, Ltd./Zormco 8520 Garfield Rd. Cleveland, OH 44125 (216) 441-6102 Delfesko Corp. 410 Cedar St. Ogdensburg, NY 13669 (800) 267-0607 or (613) 925-5987 Pro Motorcar Products Inc. 22025 US-19 North Clearwater, FL 34625 (800) 323-1090 (813) 726-9225 "We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources." Page 307 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Diagram Information and Instructions Relay Box: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Borg Warner Pinion Bearing: Adjustments Borg Warner 2 - Pinion Fig. 8 Pinion gauge plate installation Fig. 9 Checking pinion depth Page 4394 Fig. 3 Cross & Roller Type Universal Joints Fig. 4 Cross & Roller Type Universal Joints & Propeller Shaft Before disassembling any universal joint, examine the assembly carefully and note the position of the grease fitting (if used). Also, be sure to mark the yokes with relation to the propeller shaft so they may be reassembled in the same relative position. Failure to observe these precautions may produce rough vehicle operation which results in rapid wear and failure of parts, and place an unbalanced load on transmission, engine and rear axle. When universal joints are disassembled for lubrication or inspection, and the old parts are to be reinstalled, special care must be exercised to avoid damage to universal joint spider or cross and bearing cups. Some driveshafts use an injected nylon retainer to hold the bearing cups. When service is necessary, pressing the cups out will sheer the nylon retainer, Fig. 1. Replacement with the conventional steel snap ring type is then necessary, Fig. 2. Figs. 3 and 4 illustrate typical examples of universal joints of this type. They all operate on the same principle and similar service and replacement procedures may be applied to all. Fig. 7 Removing Bearing Cups Using Tool & Adapter Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Locations LH I/P Harness Wiring Page 7193 Brake Vacuum Release Valve: Adjustments With brake or clutch pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Page 1203 Use the octagon sockets on the straight fittings (J 39037 high side, and J 41256 low side). Torque the new fitting until it seats. The fitting should seat fully BEFORE reaching 11 N.m (8 lb ft). If 11 N.m (8 lb ft) of torque is reached and the fitting has not seated, it is probable that the threads have been damaged. In this case, remove the fitting and use the thread restorer listed above. Reinstall the fitting, adding one drop of a thread locking compound such as Loctite(R) 242. The fittings (except the two-piece) have a thread locking compound applied to the threads. This compound will set up enough to restrict removal of the fitting in about 15 minutes. The fittings can now be used to evacuate the system (see Step 5). An additional type of conversion port fitting has been developed. This fitting is called a saddle clamp valve (see Figure 5). It can be clamped directly on a metal refrigerant line, and will be used if the existing fitting is damaged or is inaccessible. A drop of a thread locking compound, such as Loctite(R) 242, should be used on each bolt to prevent the threads from loosening. The R134a saddle clamp valve part numbers are: If an existing R-12 service port is not used, it must be rendered inoperative. Place several drops of a thread locking compound, such as Loctite(R) 243, in the valve core, and onto the cap threads. Secure the cap and let it set for 15 minutes. 4. Install Any Additional Parts Needed See "Platform Details" after Step 6. If a vehicle is listed as a "Basic Retrofit", no additional parts are required (except for compressors, see the Compressor Replacement Chart at the beginning of Platform Details). If no parts are required, PROCEED TO STEP 5. Compressors Compressors do not need to be replaced as part of a normal retrofit, unless indicated in the Compressor Replacement Chart. An R-12 compressor that is operating properly can, in most cases, be left in the vehicle when it is retrofitted to R134a. However, if a compressor failure is the reason the vehicle is in for service, and the vehicle will be retrofitted, OR if a vehicle has already been retrofitted with R-134a and the compressor fails at some time in the future, new compressors for use with R-134a are available. See the GMSPO Parts Catalog for specific part numbers. DO NOT use a replacement R-12 compressor for any vehicle retrofitted to R-134a (unless it is the new "oil-less" design). See "Compressor Availability" at the end of the Compressor Replacement Chart. Accumulator /Dryer If the vehicle is more than 5 years old, the Accumulator/Dryer (A/D) should be replaced to ensure that moisture is removed from the system. See the instructions for proper A/D identification in General Information. High Pressure Cut-Off Switch (HPCOS) Most trucks, and some 1984-93 B and D cars, require that a HPCOS be added to protect the refrigerant system during long idles at high temperature. The HPCOS kit (P/N 15981985) contains the switch, wire harness, heat sealing splice connectors, switch "0" ring, and installation instructions. A saddle clamp adapter (P/N 15985307), or a special dual fitting, is mounted to the high pressure line, and provides the port to mount the switch. A drop of a Page 4546 Brake Fluid Pump: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 5587 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 4602 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 421 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 3381 Fuel Gauge Sender: Testing and Inspection Diagnostic Circuit Check Page 2175 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Page 3948 A. Use a micrometer to measure the original pump rotor and slide thickness accurately (Figure 3). To obtain the most accurate reading, measure on flat undamaged surfaces. The oil pump rotor and slides for the THM 200-4R and the THM 700-R4 transmissions are the same. B. Using the original part measurement, order replacement parts according to the selective charts. Note The replacement part will provide the same clearance that the oil pump assembly was originally built with. The proper end clearance specification is 0.020 to 0.050 mm. or (.0008") to (.002") for the 200-4R and the 700-R4. C. Hone both sides of the replacement rotor and slide to remove any burrs, and measure the replacement parts with a micrometer to assure proper selection. Note Incorrect rotor selection could result in a damaged oil pump assembly, and/or low oil pressure. Incorrect slide selection could result in incorrect line pressure. Page 5396 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 7408 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Tires - Slipping on Rim Wheels: Customer Interest Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Locations Fusible Link: Locations RH Front Side Of Engine. LH Front Of Engine Applicable to: 4.3L/V6-262 Turbo Engine Page 8371 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 7398 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 8670 Front Door Window Regulator NOTE: Images shown are for manual windows, power windows are similar REMOVE OR DISCONNECT 1. Door trim panel. 2. Armrest bracket. 3. Water deflector. ^ Raise the window to the full-up position secure the glass to the door frame using cloth backed tape. 4. Bolts securing the regulator to the door inner panel. 5. Regulator lift arm roller from the window mount sash. 6. Regulator from the door. INSTALL OR CONNECT 1. Regulator to the door. 2. Regulator lift arm roller to the window mount sash. 3. Bolts securing the regulator to the door inner panel. 4. Water deflector. 5. Armrest bracket. 6. Door trim panel. Adjustments Cruise Control Servo Cable: Adjustments 1. Ensure throttle is completely closed and ignition is off. 2. On Astro, Safari, S-10 and S-15 models, adjust servo cable/linkage to 0.15-0.39 inch clearance at throttle stud. 3. On R/V & G models with gasoline engine, adjust servo linkage to 0.0197-0.0394 inch clearance at throttle stud. 4. On R/V models with diesel engine, adjust servo linkage to .0393 inch clearance at center of linkage. 5. On G models with diesel engines, use third ball on servo chain. Adjust cable jam nuts until cable sleeve at throttle lever is tight, without holding throttle open. 6. On Lumina APV, Silhouette and Trans Sport, pull servo end of cable assembly towards servo as far as possible without moving throttle, then connect cable to closest hole in servo without moving throttle. Page 2516 Knock Sensor: Testing and Inspection Electronic Spark Control (ESC) Circuit Check With Power Windows Window Regulator: Service and Repair With Power Windows Door Armrest Replacement Front Door Trim Panel REMOVE OR DISCONNECT 1. Screws securing the armrest to the door trim. 2. Armrest from the door trim. ^ Slide the armrest towards the rear of the door, and then, lift the armrest from the door. INSTALL OR CONNECT 1. Armrest to the door trim. ^ Place the armrest retaining clips in the slots on the door panel. ^ Slide the armrest toward the front of the door unit the holes in the armrest align with the holes in the door trim. 2. Screws securing the armrest to the door trim. Door Trim Panel Replacement Page 6419 Retrofit Requirements The customer should be reminded that there is NO requirement in the U.S. to retrofit any vehicle produced with R-12. Vehicles built with R-12 can be serviced with R-12 as long as it is available (except in certain Canadian Provinces). GM has taken steps to extend the supply of R-12 and recommends that all R-12 vehicles continue to be serviced with R-12 as long as it is available. Training Video Before doing a retrofit the first time, it is recommended that you view the Certified Plus Training Video, Program number 51010.15, "R-134a Retrofit for GM Cars and Trucks". Table of Contents A. Retrofit Procedure 1. Inspect Condition of Vehicle 2. Recover the R-12 (new method) 3. Install the service port conversion fittings 4. Install any additional parts needed 5. Evacuate and recharge with new PAG or V5 retrofit oil and R-134a 6. Install the retrofit label Platform Details Compressor Replacement Chart B. General Information 1. Performance 2. Leakage 3. Desiccant 4. Improved Cooling Performance 5. PAG or V5 Oil Compatibility 6. Refrigerant Oil Level M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot Clutch Disc: Customer Interest M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot BULLETIN NUMBER: 92-7B-149A SECTION: 7B Manual Transmission NUMBER: 1 CORPORATE REFERENCE NUMBER: 2672O1R DATE: August 1993 SUBJECT: NEUTRAL GEAR RATTLE (REPLACE CLUTCH DISK, PROM AND PILOT BUSHING) MODELS: 1990-92 C/K AND 1990-92 S/T WITH 4.3L AND 5 SPEED MANUAL TRANSMISSION This bulletin cancels and replaces Truck Bulletin 92-7B-149 (corp. # 267201R) dated December 1992, and is being revised to add the 1992 model year S/T Trucks with 4.3L engines (RPO LB4) and to add the "Detonation and Neutral Gear Rattle Proms" section. CONDITION Some owners of 1990-92 C/K and 1990-92 S/T Trucks with 4.3L engines (RPO LB4) and 5-speed manual transmission (RPO's MG5, MY2) may comment that the transmission rattles when in neutral with their foot off the clutch pedal and the engine at idle. The customer may describe the rattle as loose bearings. CAUSE This rattle noise is created when the turning transmission gears contact against each other. The contact is created by the firing impulses of the engine which causes rapid acceleration and deceleration of the individual gears. CORRECTION This condition may be corrected by the installation of the following parts: - A revised clutch driven disc which features a live degree neutral stage. This neutral stage helps to smooth the rapid acceleration and deceleration of the individual transmission gears. - A revised PROM which raises engine idle speed to 650 RPM on C/K and 700 RPM on S/T. This increase in idle speed helps to smooth the engine firing pulses. - A clutch pilot bearing rather than a clutch pilot bushing. This bearing helps to isolate the transmission from the engine idle acceleration/deceleration. SERVICE PROCEDURE Important Incorrect engine idle can contribute to neutral gear rattle. Before installing the parts listed in this bulletin, refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 2, Driveability Symptoms "Rough, Unstable or Incorrect Idle Stalling" to verify there are no existing conditions contributing to a rough idle which may aggravate neutral gear rattle. Clutch Disc and Pilot Bearing Replacement: Refer to the appropriate year and model Service manual, Section 7C "Clutch Assembly and Pilot Bearing Replacement." Important C/K trucks require pressure plate P/N 15974649 which was first used in production mid-1991. 1990 and 1991 vehicles built prior to the following VIN breakpoints require installation of P/N 15974649 unless it has already been installed in a service repair: Ft. Wayne (Z) MZ516555 Oshawa (1) M1526826 Pontiac (E) ME51G465 PROM Replacement: Refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 3 "On-Vehicle Service, PROM". Page 438 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Service and Repair Wiper Gear Box: Service and Repair 1. Disconnect battery ground cable. 2. Remove windshield wiper arms. 3. Remove cowl vent and grille. 4. Remove motor assembly to wiper linkage retaining nut. 5. Remove screws securing wiper linkage to cowl panel and lift out linkage. 6. Reverse procedure to install. Torque all attaching fasteners to 49-80 inch lbs. Page 6416 Refrigerant: Technical Service Bulletins A/C Refrigerant - Contamination File In Section: 1 - HVAC Bulletin No.: 43-12-23 Date: September, 1994 Subject: Contaminated A/C Refrigerant Models: 1994 and Prior Passenger Cars and Trucks with R12 Air Conditioning Systems Government regulations limit the production of R12 refrigerant, commonly referred to as Freon, during 1994/1995 and restrict manufacture of new R12 material effective January 1, 1996. As R12 prices rise and supplies are depleted, it is anticipated non-approved substitute refrigerants and/or poor quality R12 material sold as new or reprocessed may become more prevalent. The Mobile Air Conditioning Society (MACS) recently expressed concern over reports of the sale of R12 refrigerant containing as high as 15% contamination by R22, a refrigerant commonly used in stationary home systems but unsuitable for use in mobile units. GM dealers should be careful to protect against contaminating their existing supplies of R12 or the A/C systems in customers' vehicles they service by dealing with reputable suppliers. All R12 refrigerant purchased for warranty repairs should be purchased through GM SPO to ensure GM quality standards are met. The use of non-approved R12 refrigerant substitutes, some of which contain flammable materials, has also been reported by MACS. These products are available to "do-it-yourselfers" who, in many cases, believe they are harmless replacements for the small cans of R12 used so commonly in the past. Once added to the A/C system, the vehicle can no longer be serviced using R12 recovery/recycling equipment without: - Risking permanent damage to recovery/recycling equipment - Contaminating the previously recovered R12 material in the recovery tank - Spreading the contamination when the recovered material is used to charge other vehicles or - Possible loss of the recovered material if the contaminated level is high enough to activate the air purge system Contaminated refrigerant also impacts customer satisfaction through poor vehicle A/C performance and loss of A/C system compressor/component durability. System or component failure resulting from the use of refrigerant which does not meet GM specification is not covered by the "New Vehicle Warranty". Unfortunately, there is no simple method to identify if a "do-it-yourselfer" or repair shop has added to or recharged a system with a non-approved refrigerant. The inability to protect against the spread of contaminated refrigerant threatens the recycling program and the industry's desire to maximize use of the remaining R12 supply. Beginning in 1993, General Motors STG, Harrison Division, Research Labs and Kent-Moore worked in conjunction with suppliers of various technologies to develop a tester to identify contaminated refrigerant in vehicle A/C systems before recovery. During development of the technology, several dealer service manager focus group studies were conducted to identify design features to best suit dealership needs. The discussions and surveys clearly indicated the desire for a dedicated instrument, permanently mounted to the refrigerant recovery cart to ensure ALL vehicles are automatically tested prior to recovering refrigerant. Testing ALL refrigerant for contamination prior to recovery is the ONLY means to ensure customer satisfaction, protect recovery equipment and avoid unintentional venting of refrigerant by your dealership. General Motors has evaluated all available technology for this project and only the J 39851 R12 "Pureguard" meets General Motors' specifications. The J 39851 R12 Pureguard Refrigerant Monitor has been classified as an essential tool and will be shipped by Kent-Moore to your dealership beginning in September of 1994. The essential price of the R12 "Pureguard" is $561 (for Canadian dealers the price is $800 Canadian). If your dealership has multiple R12 recovery equipment, additional units may be ordered from Kent-Moore for $561 at 1-800-345-2233. Features of the R12 "Pureguard" include: - Universally mounts to R12 Recovery Equipment - Automatically interrupts power to the Recovery Equipment when contaminated refrigerant is identified - Fully automatic design does not require technician action, training or interpretation - LCD displays Pureguard functions Page 7628 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 1520 Page 6284 2. Place the Temperature and Mode controls in the upper position. 3. Apply thumb pressure to each of these control knobs to hold them in the upper position while using a small screw driver to pry off the knobs (Figure 1). 4. Use the same procedure to remove the blower switch knob. 5. Disconnect the 2 light sockets from the housing by twisting the sockets counterclockwise. Page 4697 If the drum was resurfaced, verify that all metal shavings have been removed. - If the wheel cylinders were replaced or overhauled, verify that the pistons are fully compressed. Newly installed or rebuilt wheel cylinders may initially stick in the extended position (prior to bleeding the system). Using brake assembly lubricant when overhauling the wheel-cylinder will help prevent this. Page 8015 Use applicable labor time guide for labor hours. Page 4978 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Locations Engine Wiring, LH Side Page 6513 Another condition that may occur is the belt not extending when desired. This is often caused by the belt, after having been in the ratchet mode, not being retracted all the way back to the stop. Usually aiding the belt back to the stop by wiggling, removing obstructions, pulling releasing, etc. will allow the belt to once again extend. This condition frequently happens when the shoulder portion of the belt fully retracts before the lap portion of the belt reaches the stop. All the conditions described above are part of the normal operation of belts equipped with the child hold out mechanism, and will not be eliminated by replacing the belt. Page 1677 - Use care when engaging the front of the oil pan seal with the bottom of the front cover. Lubricate the front of the oil pan seal with engine oil to aid assembly. 16. Crankshaft front oil seal to the front cover. Use J 35468. 17. Oil pan bolts, nuts, and reinforcements. 18. Flywheel inspection cover. 19. Torsional damper. Use J 23523-E. 20. Coolant pump. 21. Pencil brace to coolant pump. 22. Multiple ribbed belt. 23. Fan assembly. 24. A/C condenser. 25. Radiator. 26. Lower radiator hose. 27. Heater hose and overflow hose to radiator. 28. Upper radiator hose. 29. Transmission cooler lines to the radiator. 30. Oil cooler lines to the radiator. 31. Upper radiator shroud. 32. Air cleaner and air intake duct. 33. Negative battery cable. - Fill crankcase with proper quantity and grade of engine oil. - Fill cooling system with proper quantity and grade of coolant. Page 5674 Steering Gear: Service and Repair Saginaw Rack & Pinion Power Steering Gear System Flushing 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return line at pump reservoir inlet connector, then plug inlet connector port on pump reservoir. 3. Position fluid return line in large container. 4. While a second person fills reservoir with power steering fluid, start engine at idle. 5. Turn steering wheel from stop to stop. Do not hold wheel against stops while flushing system. Holding steering wheel against stops will cause high system pressure, overheating and damage to pump and/or gear. 6. Continue draining until all old fluid is cleared from power steering system. The addition of approximately one quart of new fluid will be required to flush system. 7. Unplug pump reservoir inlet and reconnect return line. 8. Turn engine Off, and fill reservoir to Full Cold mark. 9. Bleed system as outlined under SYSTEM BLEEDING. System Bleeding If system has been serviced, an accurate fluid level reading cannot be obtained unless air is bled from system. Any air in the system may cause pump cavitation noise and may cause pump damage over time. 1. With engine off, front wheels off ground and wheels turned to far left, add power steering fluid to FULL COLD mark. 2. Bleed system by turning wheels several times from side to side without hitting stops. Add fluid if necessary. 3. Fluid with air has a light tan appearance. Air must be removed before normal steering can be obtained. 4. Start engine, recheck fluid level and add if necessary. 5. Return wheels to center position. Lower vehicle to ground and continue running engine for 2-3 minutes. 6. Road test vehicle to ensure steering functions properly and is free from noise. check fluid level and add if necessary. Page 7180 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 1129 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Adjustments Idle Speed Control Motor: Adjustments Base Idle Speed is not adjustable on this engine and is controlled by the control module. Refer to FUEL SUPPLY AND AIR INDUCTION/ADJUSTMENT PROCEDURES for adjusting Controlled Idle Speed. Page 4385 Fig. 1. Replacement with the conventional steel snap ring type is then necessary, Fig. 2. Fig. 11 Bearing Cup Removal Sequence Fig. 12 Alignment Punch Marks Fig. 13 Cross Press Being Used In Place Of Socket Locations Engine Wiring, LH Side Page 8584 Vanity Lamp: Description and Operation ILLUMINATED LEFT AND RIGHT VANITY MIRRORS Voltage for the illuminated vanity mirrors is supplied through the HORN-DM Fuse which is hot at all times. When the mirror cover is opened, the switch closes and the ground path is completed to the visor attaching screws. By moving the HI/LO selector switch on the mirror, the lamp intensity can be changed. REARVIEW MIRROR MAP/READING LIGHT Voltage for the map/reading light is supplied by the RADIO fuse. When the ON/OFF selector switch is closed, the ground path is completed and the lamp illuminates. Page 640 Manifold Pressure/Vacuum Sensor: Description and Operation Map Sensor Circuit (GM Generic) Manifold Absolute Pressure (MAP) Sensor PURPOSE The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. As intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the control module to automatically adjust for different altitudes. The PCM uses information from the MAP sensor to calculate spark advance and fuel as follows: Low MAP output voltage (low pressure) results in more spark advance. - High MAP output voltage (high pressure) results in less spark advance. - Low MAP output voltage (low pressure) results in less fuel. - High MAP output voltage (high pressure) results in more fuel. OPERATION The control module supplies a 5 volt reference signal to the MAP sensor and the sensor provides a path to ground through its variable resistor. The control module by monitoring the sensor output voltage can determine the manifold pressure. A closed throttle on engine coastdown will produce a relatively low MAP output, while a wide open throttle will produce a high output. At higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum. At lower pressure output voltage will be about 1 to 2 volts at idle. A failure in the MAP sensor circuit should set Diagnostic Trouble Codes (DTC) 33 or 34 with PCM/ECM systems and DTC P0107 or P0108 with VCM systems. Page 2517 Electronic Spark Control (ESC) Circuit Circuit Description: The Code 43 circuit consists of two knock sensors with one wire that goes directly to the ECM. There are two Code 43 checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 4.4 volts. If voltage is either too high or too low for 2 or more seconds, Code 43 will set. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3800 rpm, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, Code 43 will set. Diagnostic Aids: The ECM applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the ECM, is able to read this signal as knock and incrementally retard spark. If the ESC system checks OK, but detonation is the complaint, See: Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Page 7668 Audible Warning Device: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 6148 It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Installing Pulley Rotor Bearing 1. Place the pulley rotor on the J 21352-A support block to fully support the rotor hub during bearing installation. NOTICE: Do Not support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using puller and bearing installer J 9481-A with universal handle J 29886, drive the bearing fully into the hub. The installer will apply force to the outer race of the bearing if used as shown. 3. Place bearing staking guide J 33019-1 and bearing staking pin J 33019 in the hub bore as shown in Figure Staking Bearing In Rotor Hub Bore 13. Shift the rotor and bearing assembly on the J 21352-A support block to give full support of the hub under the staking pin location. A heavy-duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide after each impact on the pin. 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to but not touching the bearing. Page 7323 Figure 7 Figure 8 Figure 9 Figure 10 Spark Plugs - Revised Spark Plug: Technical Service Bulletins Spark Plugs - Revised Number: 93-03-6D Section: 6D Date: AUGUST 1992 Corporate Bulletin No.: 166001R ASE No.: Al, A6, A8 Subject: NEW DESIGN SPARK PLUGS Model and Yew: 1991-93 ALL PASSENGER CARS AND TRUCKS WITH GASOLINE ENGINES THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO., 91-234A-OB, DATED JULY 1992. THE 1992 AND 1993 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 91-234A-OB SHOULD BE DISCARDED. In 1991 GM introduced a new design spark plug for use in all trucks equipped with gas engines. These new design spark plugs have a ceramic insulator which is approximately 1/8 inch longer than the insulator used in previous model years. The longer length spark plugs, which conform to S.A.E. and I.S.O. Engineering guidelines, magnify the problem of cracked insulators because currently, most spark plug sockets are not of sufficient length to properly engage the shell hex. If the spark plug shell hex is not fully engaged in the spark plug socket wrench, the socket may cock at an angle and cause insulator cracking and/or breakage during plug installation or removal. When servicing these new design spark plugs, make sure that the spark plug socket being used is deep enough to accommodate the longer length insulator. The spark plug socket wrench should conform to the proposed S.A.E. and I.S.O. world standards for spark plug socket wrenches. Spark plug socket wrenches that conform to these standards are designed to accept the lengthened spark plugs and allow full engagement of the hex nut on the shell of the spark plug. Use of a spark plug socket which is NOT deep enough may result in the ceramic insulator becoming cracked above the spark plug shell. Note: SOME CRACKS IN THE INSULATOR M" NOT BE VISIBLE. SUCH CRACKS MAY LATER CAUSE A SPARK PLUG TO MISFIRE. SPARK PLUG MISFIRES ARE OFTEN MISDIAGNOSED AS A SLIPPING TRANSMISSION, DEFECTIVE TORQUE CONVERTER CLUTCH, ENGINE IMBALANCE, OR MALFUNCTIONING FUEL SYSTEM. To prevent insulator damage, it is recommended that the proper spark plug socket wrench be used when removing or replacing spark plugs. One such spark plug socket is the Kent-Moore J-39358 spark plug socket. The tool is available from Kent-Moore. For ordering information call 1 -800-345-2233 or write: Kent-Moore SPX Corporation 39784 Little Mack Roseville, MI 48066-2298 Fax: 313-774-9870 Page 5176 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 1498 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Page 7823 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 6363 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Page 5323 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 8121 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 1770 Disclaimer 4L60 (THM 700-R4) Automatic Transmission Valve Body: Locations 4L60 (THM 700-R4) Automatic Transmission Case Checkballs And Oil Screens - Locations Valve Body Checkball Locations Specifications Water Pump: Specifications Water Outlet Bolts 21 ft.lb Water Pump Bolts 30 ft.lb A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Warranty - Guidelines for Claiming Windshield Replace Windshield: All Technical Service Bulletins Warranty - Guidelines for Claiming Windshield Replace File In Section: Warranty Administration Bulletin No.: 72-05-04 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Claiming C0034 - Windshield Replacement Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide retail and wholesale service personnel with guidelines for using the above subject labor operations. In an effort to understand the windshield replacements, the following two phase approval process is being implemented. We feel this approach will allow GM to be responsive to repair decisions on vehicles over 10,000 miles (16,000KMS), while providing you, our dealers, the empowerment to address customer needs on those cases requiring repairs early in the vehicle's life, under 10,000 miles (16,000KMS). Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Windshield replacement on vehicles under 10,000 miles (16,0OOKMS) can only be made after Service Management inspection, review and approval. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. ^ Windshield replacement on vehicles over 10,000 miles (16,000KMS) can only be made after Service Management inspection, review and approval from the divisional service representative. Vehicles may be required to be held for wholesale inspection. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. The claim will require wholesale authorization for payment. Additional Requirements ^ Windshields replaced must be held for the normal parts retention period and the defect should be clearly identified on the glass by means of tape and/or a grease pencil. ^ Sublet windshield replacements, like other sublet repairs are to be claimed for actual dealership cost less any discounts and or allowances offered. Sublet repairs cannot exceed the normal allowance provided to the dealership had the repair been completed in-house. See your GM Policy and Procedure Manual for the complete guidelines. Windshields damaged by normal wear, road hazards, vandalism, or other physical damage are not eligible for warranty coverage. Page 3452 Fuel Pump Relay: Service and Repair Relay Center 2.5L,2.8L S REMOVE/DISCONNECT - Verify that ignition switch is in the "OFF" position. - Retainer, if installed. - Electrical connector. - Fuel pump relay by depressing bracket clip at rear of relay, or removing bolts from retaining bracket. INSTALL/DISCONNECT - Fuel pump relay. - Electrical connector. - Retainer. - Verify correct operation to confirm repair. Page 6177 Tools Required: J 4245 Internal Snap Ring Pliers J 6435 External Snap Ring Pliers J 29640 Shaft Protector J 29886 Driver Handle J 37872 Spanner Wrench J 38467 Bearing Remover and Installer 1. Field coil and snap ring retainer - The coil flange protrusions must match the hole in the front housing to prevent coil movement and to correctly place the lead wire. 2. Rotor pulley (5) to the front housing hub and align. - Place J 38467 into the bearing cavity with the outer edge on the rotor bearing outer race. Installing The Rotor Pulley - Place J 29886 into the ring. - Use a hammer to tap the end 29886 to guide the rotor until it bottoms out against the compressor front housing hub. Listen for a distinct change of sound during the tapping process. 3. Internal bearing snap ring with J 4245. 4. External front housing snap ring with 6435. 5. Shaft key (27). 6. Front plate assembly. - Align the front plate keyway to the compressor shaft key. 7. J 29640 to the compressor shaft. - Tap the front plate to the shaft until the late bottoms to the clutch shims. 8. Shaft hex nut. - Hold the plate with J 37872. Tighten Nut to 36 N.m (27 ft.lbs.). - Check the air gap with a feeler gauge. It should be 0.49 to 0.79 mm (0.016 to 0.031 inch). If the gap is not consistent all around, pry up slightly at points of minimum variation. Lightly tap down at points of maximum variation. The gap 5 determined by the shims. If necessary, add to or remove, shims from the shim stack. Locations Brake Fluid Level Sensor/Switch: Locations At Brake Fluid Reservoir Page 5336 Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode wire ends to protect the diode from excess heat. Follow the manufacturers instructions for the solderin equipment you are using. 5. Install terminal(s) into the connector body if previously removed in step number 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion completely cover all exposed wire and diode attachment points. NOTE: A universal diode with a 3 amp, 400 PIV (Peak Inverse Voltage) rating can be used in all of the previously mentioned applications. The following 1993 Service Manuals will need to be updated with the correct part numbers and rating changes. Carline Page All J, L, W, and UO 8A-5-12 Heat sink, part number 276-1567, can be obtained from Radio Shack. We believe the diodes and heat sink listed in this article as well as their manufacturer to be reliable. There may be additional manufacturers or equivalent products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. Engine - Block Heater Leaks Engine Block Heater: All Technical Service Bulletins Engine - Block Heater Leaks Number: 92-159-9E Section: 9E Date: APRIL 1992 Corporate Bulletin No.: 266201 ASE No.: A7 Subject: ENGINE BLOCK HEATER LEAKS Model and Year: 1976-92 LIGHT DUTY TRUCKS Some owners of 1976-1992 light duty truck engines may experience a leaking condition from the engine block heater. This condition may be caused by the block heater losing torque because the yoke, which secures the block heater, has cracked. This could cause a loss of engine coolant. The block heater brass yoke may crack due to stress corrosion where it contacts the stainless steel crossbar. The yoke is stressed or cracked from over torquing the hold down screw (Figure 1, "6"). Corrosion in the stressed area is accelerated due to the dissimilar metals. To correct this condition, a redesigned block heater should be installed. The yoke material (Figure 1 "3") of the block heater was changed from brass to stainless steel. The stainless steel is a higher strength material which reduces the possibility of stress corrosion and galvanic potential. SERVICE PROCEDURE: Follow the "ENGINE BLOCK HEATER REPLACEMENT" instructions in section 9E ENGINE BLOCK HEATER of the appropriate Service Manual. CAUTION: The gasket "O" ring seals between the block heater and the block. Excessive tightening is not necessary. The torque specification is 1.6 - 2.2 N-m (15.0 - 20.0 lbs.in.) The revised engine block heater (P/N 10154624) can be used in any light duty truck, gas or diesel engine, where an engine block heater is used. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION Qty/Veh 10154624 Engine Block Heater 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Page 5443 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 1344 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Left Side Knock Sensor Engine Wiring, LH Side Page 4219 Providing responsible services at the proper intervals will greatly aid your dealership with repeat business, and additional services when required. Most customers appreciate and gain trust in the dealership that informs and offers them just what they need for continued trouble-free operation. Examine your service department's practices and verify that all Service Consultants and Technicians focus on customer satisfaction, vehicle inspections, and other products at time of service. Use this opportunity to upgrade the services you provide to your customers. Here are a few suggestions: - Take the time required to align your dealership service practices with the new GM Simplified Maintenance Schedule. Use the new vehicle Owner's Manual Maintenance I and II schedules to create a "mirror image" in your advertising and dealer service pricing that is easily understandable to your customer. Taking advantage of this new service strategy may greatly increase your dealership service sales and customer retention while decreasing the frequency of visits and inconvenience to your customer. - Review your program to ensure that all vehicles coming in are evaluated for safety and wear items. Examine all vehicles for tire condition, signs of misalignment, brake wear, exterior lamp functionality, exhaust condition, A/C cooling performance, SRS or Air Bag MIL, along with Service Engine Soon or Check Engine indicators. If the Service Engine Soon or Check Engine MIL is illuminated, it is vital that you inform the customer of the concerns with ignoring the indicator and what the required repair would cost. In addition to the possibility of increased emissions and driveability concerns, many customers are unaware that lower gas mileage may also result, with additional cost to the customer. - Be complete in your service recommendations. Some sales opportunities are not being fully pursued nationally. Focus on overlooked but required maintenance that has real benefits to the customer. Many vehicles are equipped with cabin air filters. If these filters are used beyond replacement time, they may impede airflow decreasing A/C and heating performance. Make sure these filters are part of your recommended service. Note that some of our vehicles may not have been factory equipped but will accept the filters as an accessory. - Express the value in maintaining the finish quality of the customer's vehicle at the Maintenance I and II visits. More fully utilize the vehicle prep personnel you already have in place. In today's world, many people simply ignore the finish of their vehicle, at best infrequently using an automatic car wash for exterior cleaning. Offer vehicle detailing services in stages from just a wash and wax to a complete interior cleaning. When paired with the Simplified Maintenance visit, this will increase customer satisfaction. On return, the customer gets a visibly improved vehicle that will be a source of pride of ownership along with a vehicle that is now fully maintained. Also, reinforce the improved resale value of a completely maintained vehicle. - For customers who clean and maintain the appearance of their vehicles themselves encourage the use of GM Vehicle Care products. Many customers may have never used GM Car Wash/Wax Concentrate, GM Cleaner Wax or a longtime product, GM Glass Cleaner, which is a favorite of many customers who try it just once. If your dealership give samples of these products with new car purchases, customers may already be sold on the product but not willing to make a special trip to the dealership. Capitalize on sales at this time. Stock shelves right at the Service counter with these products and consider instituting compensation programs for Service Consultants who suggest these products. Many consumers faced with an intimidating wall full of car care products sold at local auto parts stores may find it comforting to purchase a fully tested product sold by GM that they know will not harm the finish of their vehicle. We suggest these competitively priced basic vehicle care products to emphasize: In USA: - #12378401 GM Vehicle Care Wash/Wax Concentrate 16 fl. oz. (0.473L) - #89021822 GM Vehicle Care Glass Cleaner Aerosol 18 oz. (510 g) - #12377966 GM Vehicle Care Cleaner Wax 16 fl. oz. (0.473L) - #1052929 GM Vehicle Care Chrome and Wire Wheel Cleaner 16 fl. oz. (0.473L) - #88861431 GM Vehicle Care Odor Eliminator 24 fl. oz. (0.710L) In Canada: - #10953203 GM Vehicle Care Wash & Wax Concentrate 473 mL - #992727 GM Glass Cleaner Aerosol 500 g - #10952905 GM Vehicle Care Liquid Cleaner/Wax 473 mL - #10953013 GM Vehicle Care Chrome Cleaner and Polish 454 mL - #10953202 GM Vehicle Care Wheel Brite 473 mL - #88901678 GM Vehicle Care Odor Eliminator 473 mL - Display signboards with the installed price for popular GM Accessories such as running boards and Tonneau Covers. Customers may not think to ask about these desirable items at the time of a service visit. - Finally, take advantage of the GM Goodwrench initiatives (Tire Program, Goodwrench Credit Card, etc. / Dealer Marketing Association (DMA) Promotions in Canada) to provide the customer with more reasons to identify your dealership as the best place to go for parts and service. Remember to utilize ALL of the service aspects you possess in your dealership to satisfy and provide value to your customer. Many businesses exist profitably as an oil change location, a vehicle repair facility, or a detailing shop alone. You already have the capabilities of all three and provide these services with the inherent trust of your customer, under the GM Mark of Excellence. Disclaimer Control Module Replacement Engine Control Module: Service and Repair Control Module Replacement Figure 1 CAUTION [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, Do NOT touch the connector pins or soldered components on the circuit boards. NOTE When replacing a production control module with a service controller, transfer the broadcast code and production control module part number to the controller label. DO NOT record information on the access cover. REMOVE/DISCONNECT - Negative battery terminal. - Passenger side kick panel. - Hush panel if equipped. - Mounting screw. - Control module from mounting bracket. - VSS buffer connector and rotate control module to ease removal. - Control module harness connectors. - Mounting brackets and modules if equipped. - Remove new control module from its packaging and check the service number to make sure it is the same as the defective control module. - PROM removal. Refer to PROM (MEM-CAL) replacement. NOTE Replacement control module is supplied without a PROM, so care should be used when removing it from the defective control module, because it will be reused in the new control module. INSTALL/CONNECT - Mounting brackets and modules if equipped. - Control module harness connectors. - VSS buffer connector and rotate control module to ease installation. - Control module into mounting bracket. - Mounting screw. - Hush panel if equipped. - Passenger side kick panel. Page 2270 Fan Clutch: Service and Repair To prevent silicone fluid from draining into fan drive bearing, do not store or place drive unit on bench with rear of shaft pointing downward. The coil spring type fan clutch cannot be disassembled, serviced or repaired. If it does not function properly, it must be replaced with a new unit. To replace the fan clutch, use the following procedure: 1. Remove the radiator fan shroud. 2. Unfasten the unit from the water pump, then remove the assembly from vehicle. 3. Separate fan from fan clutch. 4. Reverse procedure to install, noting the following: a. Ensure mating surfaces of water pump hub and fan clutch hub are smooth and free of any burrs. b. Align yellow reference marks on water pump hub and fan clutch hub. c. Torque nuts to 18 ft. lbs. Page 314 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 7420 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Rocker Arm Studs Replace Rocker Arm Assembly: Service and Repair Rocker Arm Studs Replace Fig. 10 Rocker Arm Stud Removal Fig. 11 Reaming Of Rocker Arm Stud Bore Fig. 12 Installing Rocker Arm Stud Rocker arm studs that have damaged threads or are loose should be replaced with oversize studs. Oversize studs are available in .003 and .013 inch and can be installed after properly reaming the holes as follows: 1. Remove stud using stud reamer tool No. J-5802-01, Fig. 10 or equivalent with a nut and flat washer placed over the tool. 2. Ream hole to proper size using reamer tool No. J-5715, Fig. 11 for .003 inch oversize or reamer tool No. J-6036 for .013 inch oversize. Do not install oversize stud without reaming hole since cylinder head damage could occur. 3. Apply axle lubricant to press fit area of stud and install using stud installer tool No. J-6880 or equivalent, Fig. 12. Page 385 Figure 7 Figure 8 Figure 9 Figure 10 Page 6650 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 6996 Each user will be required to accept the following agreement each time the KeyCode application is used. Key Code User Agreement - Key codes are proprietary information belonging to General Motors Corporation and to the vehicle owner. - Unauthorized access to, or use of, key code information is unlawful and may subject the user to criminal and civil penalties. - This information should be treated as strictly confidential and should not be disclosed to anyone unless authorized. I will ensure that the following information is obtained prior to releasing any Key Code information: 1. Government issued picture ID (Drivers License) 2. Registration or other proof of ownership. Registration should have normal markings from the Province that issued the registration and possibly the receipt for payment recorded as well. Important - GM takes this agreement seriously. Each user must be certain of vehicle ownership before giving out key codes. - When the ownership of the vehicle is in doubt, dealership personnel should not provide the information. Key code requests should never be received via a fax or the internet and key codes should never be provided to anyone in this manner. A face to face contact with the owner of the vehicle is the expected manner that dealers will use to release a key code or as otherwise stipulated in this bulletin or other materials. - Key codes should NEVER be sent via a fax or the internet. - Each Dealership should create a permanent file to document all KeyCode Look Up transactions. Requests should be filed by VIN and in each folder retain copies of the following: - Government issued picture ID (Drivers License) - Registration or other proof of ownership. - Copy of the paid customer receipt which has the name of the employee who cut and sold the key to the customer. - Do not put yourself or your Dealership in the position of needing to "explain" a KeyCode Look Up to either GM or law enforcement officials. - Dealership Management has the ability to review all KeyCode Look-Up transactions. - Dealership KeyCode documentation must be retained for two years. Frequently Asked Questions (FAQs) for GM of Canada Dealers How do I request a KeyCode for customer owned vehicle that is not registered? Scrapped, salvaged or stored vehicles that do not have a current registration should still have the ownership verified by requesting the vehicle title, current insurance policy and / or current lien holder information from the customers financing source. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. In these cases, a short description of the vehicle (scrapped, salvaged, etc.) and the dealership location should be kept on file. Any clarifying explanation should be entered into the comments field. How do I document a KeyCode request for a vehicle that is being repossessed? The repossessor must document ownership of the vehicle by providing a court ordered repossession order and lien-holder documents prior to providing key code information. Copies of the repossessors Drivers License and a business card should be retained by the dealership for documentation. What do I do if the registration information is locked in the vehicle? Every effort should be made to obtain complete information for each request. Each Dealership will have to decide on a case by case basis if enough information is available to verify the customer's ownership of the vehicle. Other forms of documentation include vehicle title, insurance policy, and or current lien information from the customers financing source. Dealership Management must be involved in any request without complete information. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. Can I get a print out of the information on the screen? It is important to note that the Key Code Look Up Search Results contain sensitive and/or proprietary information. For this reason GM recommends against printing it. If the Search Results must be printed, store and/or dispose of the printed copy properly to minimize the risk of improper or illegal use. Who in the dealership has access to the KeyCode application? Dealership Parts Manager (or assigned management) will determine, and control, who is authorized to access the KeyCode Look Up application. However, we anticipate that dealership parts and service management will be the primary users of the application. The KeyCode Look Up application automatically tracks each user activity session. Information tracked by the system includes: User name, User ID, all other entered data and the date/time of access. Locations A/C And Heater Wiring A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 8608 Power Window Motor: Service and Repair Door Trim Panel Front Door Trim Panel Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Compact Disc Players - CD Changer Loading Procedures Compact Disc Player (CD): All Technical Service Bulletins Compact Disc Players - CD Changer Loading Procedures File In Section: 9 - Accessories Bulletin No.: 64-96-01 Date: January, 1997 INFORMATION Subject: Compact Disc Players - Procedures for Correct Use and Maintenance Models: 1997 and Prior Passenger Cars and Trucks CD Changer Loading Procedures Because of differences in CD changer loading procedures, some confusion exists regarding this issue. Although correct loading procedures are included with each changer's Owner's Manual, often this information is not available to the dealer service personnel. Verify proper loading when evaluating customer concerns of "CD inoperative". Delco Electronics Product Type Loading Procedure Radio w/intergral CD label side up 6 disc changer (LLAI) label side up 10 disc changer (FMI) label side up 12 disc changer (LLAI) label side down Important: Failure to load magazine/player correctly will disable the operation. Important: Only the 12 disc changer is to be loaded with the label side down. CD Cleaners Avoid use of commercially available CD cleaners. The use of CD cleaners is not recommended and can damage the player's CD mechanism. Control Module Engine Control Module: Locations Control Module Figure 1 LOCATION Below RH Side Of I/P. Page 6153 1. Install the shaft key into the hub key groove (Fig. 7). Allow the key to project approximately 4.8mm (3/16") out of the keyway. The shaft key is curved slightly to provide an interference fit in the shaft key groove of the hub. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the Clutch Plate and Hub assembly. 3. Align the shaft key with the shaft keyway and place the Clutch Plate and Hub assembly Onto the compressor shaft. NOTICE: To avoid internal damage to the compressor, do not drive or pound on the clutch hub or shaft. 4. Install the Clutch Plate and Hub Installer J 9401-B as illustrated in Figure 8. 5. Hold the hex portion of the Installer Body J 9401-B with a wrench and tighten the center screw to press the hub onto the shaft until there is a 0.5-7.6mm (0.20-0.30") air gap between the frictional surfaces of the clutch plate and clutch rotor. 6. Install a new shaft nut with the small diameter boss of the nut against the crankshaft shoulder, using Thin Wall Socket J 9399-A. Hold the Clutch Plate and Hub assembly with Clutch Hub Holding Tool J 33027-A, and tighten to 14 N.m (10 lb.ft.) torque, using a 0-60 N.m (0-25 lb.ft.) torque wrench. 7. If operation is performed with compressor on vehicle, connect drive belt, tighten mounting brackets and adjust belt tension. 4 Pole Clutch V-GROOVE TYPE - 4 POLE CLUTCH Remove or Disconnect 1. Remove the Clutch Plate and Hub assembly. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 1159 Page 8678 Front Door Window Regulator REMOVE OR DISCONNECT 1. Door trim panel. 2. Armrest bracket. 3. Water deflector. ^ Raise the window to the full-up position secure the glass to the door frame using cloth backed tape. 4. Bolts securing the regulator to the door inner panel. 5. Regulator lift arm roller from the window mount sash. 6. Regulator from the door. INSTALL OR CONNECT 1. Regulator to the door. 2. Regulator lift arm roller to the window mount sash. 3. Bolts securing the regulator to the door inner panel. 4. Water deflector. 5. Armrest bracket. 6. Door trim panel. Page 5486 Convenience Center (with Digital Cluster) A/C - Retrofitting R-12 to R-134a Technical Service Bulletin # 431207E Date: 970101 A/C - Retrofitting R-12 to R-134a File In Section: 1 - HVAC Bulletin No.: 43-12-07E Date: January, 1997 INFORMATION Subject: Guidelines for Retrofitting R-12 Vehicles to R-134a Models: 1984-94 Passenger Cars and Trucks (See List Below) This bulletin is being revised with the following changes: 1. Addition of all remaining GM vehicles, as listed. 2. Format rearranged for easier use. Please discard Corporate Bulletin Number 43-12-07D (Section 1 - HVAC). Car/Truck Platform Coverage Starts: 1984 - A, B, D, E, F, J, K, P, Y Carlines 1985 - C, M, N, R, S Carlines 1986 - H Carline 1987 - L, V (Allante) Car lines; M/L, G, R/V, S/T, P Truck lines 1988 - T (LeMans), E (Reatta), W Car lines; C/k, MED. Duty Truck lines 1989 - Tracker 1990 - U Van Vehicles Not Covered: T (Chevette and T1000), G RWD, C RWD, and X Car If a vehicle is not covered in the list above, GM's recommendation is that the vehicle continue to be serviced with R-12. This bulletin outlines the detailed retrofit procedures, as well as providing background information on many components and procedures. It is important to follow the bulletin, since each car and truck line has unique parts and procedures. However, the basic procedure is simple, and will become easier as you complete more retrofits. Page 7734 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 3998 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Symptom Related Diagnostic Procedures Blower Motor: Symptom Related Diagnostic Procedures Blower Motor Does Not Operate In Any Mode Page 872 Fuel Pressure Test Port: Service and Repair Fuel Pressure Connection CLEAN Area around fuel pressure connection with GM X-30A or equivalent. REMOVE OR DISCONNECT - Negative battery terminal. - Relieve fuel system pressure. - Fuel pressure connection and seal. Discard seal. INSTALL OR CONNECT - New seal on fuel pressure connection. - Fuel pressure connection in fuel rail. Tighten Fuel pressure connection assembly to 10.0 N-m (88 lb. in.). - Tighten fuel filler cap. - Negative battery terminal. INSPECT - Turn ignition switch to the "ON" position for two seconds, then turn to the "OFF" position for ten seconds. Again turn to the "ON" position, and check for fuel leaks. NOTE Any time the battery is disconnected, the programmed position of the IAC valve pintle is lost, and replaced with a default value. To return the IAC valve pintle to the correct position, perform the following procedure: - Disconnect negative battery for at least ten seconds to clear control module memory. (Ensure ignition is "OFF".) - Reconnect negative battery cable. - "START" engine and allow engine to reach operating temperature. Check for proper idle operation. Page 6088 Blower Electrical Diagnostic Chart BLOWER INOPERATIVE When diagnosing problems in the blower electrical system, refer to the accompanying figure. Page 8003 Door Switch: Locations RH Front Door Jamb Switch In RH A-Pillar Distributor Operation Distributor: Description and Operation Distributor Operation EST Distributors With Separate Coil (Typical) Page 2043 For vehicles repaired under warranty use: Description Labor Op. Heater, Engine Block - Replace R4600 Use applicable labor time guide for labor hours. Page 1301 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 7184 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 7252 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 2920 EGR AND EVRV SOLENOID 4.3 L Page 8207 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 7460 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 3907 Disclaimer Page 7472 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 4353 Removing bearing retainer ring 7. Using a suitable pliers, remove outer bearing retaining ring, Fig. 10. 8. Using an old axle shaft or equivalent, drive on axle shaft spacer to remove outer bearing assembly from hub. 9. Position axle shaft spacer and outer bearing into hub, ensuring larger side of bearing faces outer end of hub. 10. Position outer bearing cup into hub with thin edge facing toward outer end of hub, then press cup into hub. 11. Install retaining ring, then press cup into contact with ring. 12. Drive inner bearing cup into hub, then install new oil seal. 13. Reverse Steps 1 through 5 to complete installation, then adjust wheel bearings as outlined in ``Wheel Bearing, Adjust'' procedure. Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Page 136 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 724 Rear Of Engine Page 6434 85-93 Suction hose - 94855765 85-92 Discharge hose - 94845943 1985-88 Sprint, 1989-93 Metro (M) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 500 grams (1.10 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-86 - 91172081 87-88 - 91172079 89-93 - 96068480 Adapter Fittings: Low Side - 91172092 85-88 - High Side - 91172094 89-93 - High Side - 52467941 0-Rings: Compressor - Small 0-rings (6 required) - 91172095 - Large 0-ring - 96068915 Receiver/Dryer (2) - 96068488 A/C - Retrofitting R-12 Vehicles to R-134A Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Page 6746 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 6443 Refrigerant: Specifications REFRIGERANT AND OIL CAPACITY 1. Refrigerant-12................................................................................................................................... ............................................... 1.134kg (2.5 lbs.). CAUTION: Overcharging a system may allow liquid Refrigerant-12 to get into the compressor, causing compressor noise and damage. Undercharging will cause insufficient cooling. 2. 525 Viscosity Refrigerant oil - R-4 Compressor ................................................................................................................................ ...................................... 236 ml (8.0 fl. oz.). Page 3501 Throttle Position Sensor: Mechanical Specifications Throttle Position Sensor 18 in.lb Page 7541 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Removal Notes Brake Caliper: Fundamentals and Basics Removal Notes When Removing the Caliper, Remember... - Prior to removing the calipers, remove/siphon brake fluid from master-cylinder until the reservoir is only 1/3 full. - Brake fluid will remove paint and damage electrical connections. Use a drip pan and fender covers to protect the vehicle's finish and electrical system. - Always replace all brake linings on an axle. Never replace only one wheel. Unequal lining thickness between wheels on the same axle will result in a strong steering pull when the brakes are applied. - Work on one side at a time. If you forget how to reassemble the parts you can always use the other side as a model. - When forcing the piston back into the caliper, open the bleeder valve first. Corrosion and other deposits accumulate inside of the caliper. If the bleeder valve is not opened when the piston is forced back into the caliper, these deposits will be forced back through the brake lines and into the master-cylinder. When pushing the pistons back into the caliper with the bleeder screw open, a stream of brake fluid will be expelled from the bleeder screw for 2-3 feet. Use a drip pan and be careful not to "shoot" brake fluid onto the vehicle's finish. A cleaner method is to use a piece of clear plastic hose and a glass or plastic jar to catch the expelled fluid. - Upon removal, Do Not allow the calipers to hang by the flexible brake hoses. The brake hoses can be damaged easily by this practice. These hoses are double walled, damage to the interior pressure hose will not be visible. - Do not depress the brake pedal with either caliper removed from the rotor. The caliper pistons will be inadvertently expelled from the caliper. If this occurs rebuild or replace the caliper, do not attempt to insert the piston back into the caliper. Page 5119 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 4358 Hub & Drum ROCKWELL REAR WHEEL BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. 5. Pull hub and drum straight off axle housing. Axle Housing Refer to CHEVROLET FULL FLOATING AXLES for axle housing replacement procedure. Axle Shaft REAR DRIVE AXLE Removing axle shaft. GMC single speed axle 1. Remove hub cap retaining cap screws and hub cap. 2. Install a slide hammer adapter into tapped hole in axle flange. 3. Attach slide hammer onto adapter and remove axle shaft from housing, Fig. 9. 4. Reverse procedure to install. Lubricate small end of axle shaft and install into housing using a new gasket. Torque axle flange cap screws on 15 ft. lbs. Wheel Bearings REAR WHEEL BEARINGS Specifications Valve Cover: Specifications Rocker Arm Cover Bolts 7.5 ft.lb Page 3027 Throttle Position Sensor: Description and Operation TP Sensor Throttle Position Sensor (TPS) PURPOSE The Throttle Position Sensor (TPS) is a non-adjustable potentiometer that senses throttle angle and relays the information to the control module. This input to the control module is used to control the fuel system and most of the control module outputs. CONSTRUCTION The TPS has internally three circuits. One to ground, the other from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage . As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). OPERATION As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation movement to the TP sensor. A potentiometer (variable resistor) within the Throttle Position (TP) sensor assembly changes its resistance in proportion to throttle movement. If the TP sensor senses a Wide Open Throttle (WOT) a voltage signal indicating this condition is sent to the control module. The control module then increases the injector base pulse width, permitting increased fuel flow. LOCATION The non-adjustable Throttle Position (TP) sensor, is mounted on the side of the throttle body opposite the throttle lever assembly. Page 7726 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Restraints - Extender Availability For Seat Belt Seat Belt Extension: Technical Service Bulletins Restraints - Extender Availability For Seat Belt INFORMATION Bulletin No.: 99-09-40-005F Date: June 23, 2010 Subject: Seat Belt Extender Availability Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2009‐2011 model years and update the Warranty Information. Please discard Corporate Bulletin Number 99-09-40-005E (Section 09 Restraints). Important: DO NOT use belt extenders when securing a child restraint. The seat and shoulder belt restraint systems used in all General Motors vehicles have sufficient belt length to accommodate most drivers and passengers. Consequently, requests for belt extensions (extenders) should be minimal. Seat belt extenders are available ONLY IN BLACK for most GM passenger cars and trucks produced in recent years. They are available in two different lengths, 23 cm (9 in) and 38 cm (15 in). They are designed to be coupled with the existing belts in each vehicle. When in use, the extender makes the belt arrangement a "custom fit" and use by anyone else or in another vehicle will lessen or nullify the protection offered by the vehicle's restraint system. For this reason, it is extremely important that the correct length extender be used for the vehicle and occupant intended. Important: Do not use an extender just to make it easier to buckle the safety belt. Use an extender only when you cannot buckle the safety belt without using an extender. Parts Information For part numbers, usage and availability of extenders, see Extension Kit in Group 14.875 (cars) or Group 16.714 (trucks) of the appropriate parts catalog. Saturn retailers should refer to the appropriate model year Parts & Illustration catalog for the vehicle. U.S. Saab dealers should contact the Parts Help line. Canadian Saab dealers should fax requests to Partech Canada. Warranty Information ^ Seat belt extenders are a NO CHARGE item to all GM customers who request them for their specific vehicles. ^ Dealers should not be charging part costs since these extenders are supplied by GM to the dealers. ^ Dealers should not be charging labor costs since the extender can be customer installed. Disclaimer Component Locations Power Window Switch: Component Locations Rear Window Release Solenoid In Center Of Endgate 2 Door Rear Window Release Components. Below Cigar Lighter Applicable to: 2Door Blazer & Jimmy 4 Door Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Page 1073 Contamination Mixing conventional green coolant with DEX-COOL(R) will degrade the service interval from 5 yrs./150,000 miles (240,000 km) to 2 yrs./30,000 miles (50,000 km) if left in the contaminated condition. If contamination occurs, the cooling system must be flushed twice immediately and re-filled with a 50/50 mixture of DEX-COOL(R) and clean water in order to preserve the enhanced properties and extended service interval of DEX-COOL(R). After 5 years/150,000 miles (240,000 km) After 5 yrs/150,000 miles (240,000 km), the coolant should be changed, preferably using a coolant exchanger. If the vehicle was originally equipped with DEX-COOL(R) and has not had problems with contamination from non-DEX-COOL(R) coolants, then the service interval remains the same, and the coolant does not need to be changed for another 5 yrs/150,000 miles (240,000 km) Equipment (Coolant Exchangers) The preferred method of performing coolant replacement is to use a coolant exchanger. A coolant exchanger can replace virtually all of the old coolant with new coolant. Coolant exchangers can be used to perform coolant replacement without spillage, and facilitate easy waste collection. They can also be used to lower the coolant level in a vehicle to allow for less messy servicing of cooling system components. It is recommended that you use a coolant exchanger with a vacuum feature facilitates removing trapped air from the cooling system. This is a substantial time savings over repeatedly thermo cycling the vehicle and topping-off the radiator. The vacuum feature also allows venting of a hot system to relieve system pressure. Approved coolant exchangers are available through the GMDE (General Motors Dealer Equipment) program. For refilling a cooling system that has been partially or fully drained for repairs other than coolant replacement, the Vac-N-Fill Coolant Refill Tool (GE-47716) is recommended to facilitate removal of trapped air from the cooling system during refill. Disclaimer Door Jamb Switch Door Switch: Locations Door Jamb Switch On A-Pillars Page 2844 Manifold Pressure/Vacuum Sensor: Description and Operation Map Sensor Circuit (GM Generic) Manifold Absolute Pressure (MAP) Sensor PURPOSE The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. As intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the control module to automatically adjust for different altitudes. The PCM uses information from the MAP sensor to calculate spark advance and fuel as follows: Low MAP output voltage (low pressure) results in more spark advance. - High MAP output voltage (high pressure) results in less spark advance. - Low MAP output voltage (low pressure) results in less fuel. - High MAP output voltage (high pressure) results in more fuel. OPERATION The control module supplies a 5 volt reference signal to the MAP sensor and the sensor provides a path to ground through its variable resistor. The control module by monitoring the sensor output voltage can determine the manifold pressure. A closed throttle on engine coastdown will produce a relatively low MAP output, while a wide open throttle will produce a high output. At higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum. At lower pressure output voltage will be about 1 to 2 volts at idle. A failure in the MAP sensor circuit should set Diagnostic Trouble Codes (DTC) 33 or 34 with PCM/ECM systems and DTC P0107 or P0108 with VCM systems. Engine - High Oil Pressure Reading at Start-Up Oil Pressure Gauge: All Technical Service Bulletins Engine - High Oil Pressure Reading at Start-Up Number: 93-60-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268306 ASE No.: A1, A8 Subject: HIGH OIL PRESSURE READING AT START-UP Model and Year: 1992-93 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L, AND 5.7L ENGINES Some 1992 and 1993 Chevrolet Light Duty Trucks with oil pressure gauges built after 6/15/92 may exhibit high oil pressure readings at start up, especially when cold. Engines produced after 6/15/92 were built with an enhanced oil pump capable of producing approximately 10 psi more pressure than the previous pump. This may cause the gauge to temporarily read as high as 60 psi during start up. The length of time the oil pressure stays high will depend on oil viscosity, engine temperature, and ambient temperature. This condition will not cause any ill effects on the engine or gauge and unless there are other symptoms to indicate an oil pressure or gauge problem such as very low pressure after warm up, rapid fluctuation, engine noise etc. no repairs should be attempted. Replacing the oil pump or gauge system parts will not be effective. Build date of the engine can be verified by the engine code. The location of this code is illustrated in section OA of the appropriate service manual. The engine code is 8 positions long with an alpha plant designator in the first position, followed in the next four positions by the month and day; for example T0615xxx would indicate that this engine was built in Tonawanda on June 15th and, therefore, has the enhanced oil pump. The plant code is insignificant because all 4.3L, 5.0L, and 5.7L plants began using the enhanced oil pump on the same day. A/T - Vibration/Rattle, Torque Converter Clutch Applied Torque Converter: Customer Interest A/T - Vibration/Rattle, Torque Converter Clutch Applied Number: 93-38-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277145 ASE No.: A2 Subject: DRIVELINE VIBRATION AND/OR GEAR RATTLE WITH TORQUE CONVERTER CLUTCH (TCC) APPLIED Model and Year: 1992-93 S/T TRUCKS WITH 4.3L (L35) ENGINE AND 4L60 OR 4L60-E AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1992 HYDRA-MATIC 4L60 (MD8) 1993 HYDRA-MATIC 4L60-E (M30) TRANSMISSION MODELS: 2TAM, 2TBM, 3TAD, 3TBD SUBJECT: Driveline Vibration and/or Gear Rattle with TCC Applied VEHICLE APPLICATIONS: S/T Trucks with L35 Condition: Some 1992-1993 S and T trucks equipped with 4.3 liter (L35) engine and the HYDRA-MATIC 4L60 or 4L60-E transmission built before Julian Date 223 (August 10, 1992) may exhibit a rattle or driveline vibration with the torque converter clutch (TCC) applied at low engine speeds (1000-2000 RPM). Cause: The rattle or driveline vibration may be due to the stiffness of the spring rate of the damper springs in the torque converter. Correction: Install a new torque converter assembly which corrects the rattle in the 1000-2000 RPM operating range. Diagnosis Information: The rattle or driveline vibration condition only occurs in fourth gear with TCC applied. Use the following procedure to determine if the vehicle has this condition: 1. Accelerate the vehicle to achieve fourth gear and confirm that TCC is applied. 2. Maintain low engine speed (1000-2000 RPM) then crowd the throttle to above 25 percent TPS to induce the rattle or drive line vibration. NOTE: Excessive throttle input will disengage the TCC. Applying the brake will also disengage the TCC. Service Parts Information: Part Name Part Number Torque Converter Assembly (DBAF) 8688904 Parts are currently available from GMSPO. Page 5445 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 98 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 671 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 6134 - Clamp J 9396 in a vise. Removing The Shaft Nut - Compressor to J 9396. Secure with thumb screws. 1. Shaft nut (1) with 9399-A. - Hold the clutch plate and Hub assembly (2) with J 25030-A. 2. Clutch plate and hub assembly. Removing The Clutch Plate And Hub Assembly - Thread J 9401-B into the clutch plate and hub (2) (figure 3). - Hold the body of J 9401-B with a wrench and tighten the center screw into the remover body. 2. Shaft key (36). - Retain the shaft key (36) if usable. Inspect All parts and replace as necessary. Headlight Dimmer Switch Steering Column Page 8211 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7236 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 8576 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 1326 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Brake Light Switch Brake Light Switch: Locations Brake Light Switch Cruise Control I/P Wiring Page 8667 Front Inner Panel Water Deflector NOTE: Waterproof deflectors are used to seal the door inner panel, and to prevent water from entering into the body. The deflector is secured by a strip of adhesive between the deflector and the door, as well as waterproof sealing tape. REMOVE OR DISCONNECT 1. Door trim panel. 2. Plastic fasteners (when used). 3. Armrest bracket. 4. Water deflector. ^ Pull the waterproof sealing tape from the deflector. ^ Break the bond between the sealer and the door with a flat-bladed tool. INSTALL OR CONNECT 1. Water deflector strip caulking as a sealant between the deflector and the door, If needed. 2. Plastic fasteners (when used). 3. Waterproof tape. 4. Armrest bracket. 5. Door trim panel. Window Regulator Replacement Page 4674 Brake Rotor/Disc: Fundamentals and Basics Tightening Notes WHEN TIGHTENING LUG NUTS, REMEMBER... Always tighten the lug nuts to the correct torque specification. Lightly lubricate the studs with an anti-seize compound to ensure proper torque and prevent damage to the threads. Tighten in an alternating pattern around the wheel until the wheel is centered on the studs. Do your final tightening with a torque wrench. When servicing disc brakes it is very important to properly torque the wheel assembly. Lug nuts which are installed with an air impact tool are often over-torqued. This may distort the rotor and result in excessive lateral runout (rotor wobble) and a pedal pulsation upon braking. Recheck the wheel bearings once the tires are installed. With the vehicle raised and properly supported, grasp the tire at the top and bottom and attempt to rock them back and forth. There should be no detectable lateral (wobble) movement. Page 6162 1. Assemble the Clutch Coil, Pulley Rim and the Clutch Rotor and Bearing assembly as shown in Figure 27. Use new screws and apply sealer GM 12345382 (Loctite 242, or equivalent) to screw threads but do not lock the screws in place. 2. Place the assembly on the neck of the Front Head and seat into place using Rotor & Bearing Installer J 26271-A (Fig. 14). Before fully seating the assembly on the Front Head, be sure the clutch coil terminals are in the proper location in relation to the compressor and that the three protrusions on the rear of the clutch coil align with the locator holes in the Front Head. 3. Install the rotor and bearing assembly retaining ring and reassemble the Clutch Plate and Hub assembly. Check to see that the clutch plate to clutch rotor air gap is 0.5-7.6mm (0.020-0.030"). Rotate the Pulley Rim and Rotor to be sure the Pulley Rim is rotating "in-line" and adjust or replace as required. 4. Tighten the pulley rim mounting screws to 11 N.m (100 in.lbs.) torque and lock the screw heads in place by bending screw head washer, similar to original crimp and lock bends on washers. Poly-Groove Drive Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. 2. Remove the pulley rotor and bearing assembly as described previously. Mark the location of the clutch coil terminals on the compressor. Page 3029 Throttle Position Sensor: Service and Repair Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 2884 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Page 5527 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 7188 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 321 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 3973 Seals and Gaskets: Service and Repair 1. Remove driveshaft, and tunnel strap, as equipped. 2. Using suitable tool, pry out lip oil seal. 3. Coat outer casting of new oil seal with suitable sealer and drive into place with installer J-21426. 4. Install tunnel strap if used, then install driveshaft. Page 1217 accumulator. The system will operate properly as long as refrigerant charge amounts are strictly adhered to. 6. Refrigerant Charge Level The retrofit R-134a charge level is more critical than with R-12 systems. Overcharging may push the mineral oil out of the AID, and cause it to circulate as a liquid. This is more likely to result in compressor damage. Undercharging may lead to loss of performance. It is very important to clear the hoses during the charging operation, to insure that all the refrigerant is delivered to the vehicle A/C system. This is covered in Step 6D of the Retrofit Procedure. C. Parts Information Page 6316 Evaporator And Blower Case Replacement Page 716 Throttle Position Sensor: Description and Operation TP Sensor Throttle Position Sensor (TPS) PURPOSE The Throttle Position Sensor (TPS) is a non-adjustable potentiometer that senses throttle angle and relays the information to the control module. This input to the control module is used to control the fuel system and most of the control module outputs. CONSTRUCTION The TPS has internally three circuits. One to ground, the other from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage . As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). OPERATION As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation movement to the TP sensor. A potentiometer (variable resistor) within the Throttle Position (TP) sensor assembly changes its resistance in proportion to throttle movement. If the TP sensor senses a Wide Open Throttle (WOT) a voltage signal indicating this condition is sent to the control module. The control module then increases the injector base pulse width, permitting increased fuel flow. LOCATION The non-adjustable Throttle Position (TP) sensor, is mounted on the side of the throttle body opposite the throttle lever assembly. Park Lamp, LH Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Page 7220 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 1274 Fuse: Locations Inline Fuse, Underhood Lamp Between Underhood Lamp & Junction Block Page 5101 Starter Solenoid: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 1789 2. Loosen engine mount through bolts (Figure 1, "B") and transmission mount to crossmember bolts and ensure the exhaust flexible hose is free to - move. - Loosen exhaust pipe/converter pipe clamp U-bolt (Figure 3). - Move U-bolt out of position. - Heat the exhaust pipe/converter connection joint to loosen the converter. Locations Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Page 4102 Transmission Speed Sensor: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Page 400 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 3624 Spark Plug: Description and Operation Spark Plug Identification Chart IDENTIFICATION Resistor-type, tapered-seat spark plugs are used on all engines. No gasket is used on these tapered seat plugs. Refer to image for an explanation of letter coding on spark plugs. A dot before the spark plug code or the letter "C" after the number in the code indicates the spark plug has a copper core. CONSTRUCTION AND OPERATION Normal or average service is assumed to be a mixture of idling, slow speed, and high speed operation with some of each making up the daily total driving. Occasional or intermittent high-speed driving is essential to good spark plug performance as it provides increased and sustained combustion heat that burns away any excess deposits or carbon or oxides that may have accumulated from frequent idling or continual stop and go or slow speed driving. Spark plugs are protected by an insulating boot made of special heat-resistant material which covers the spark plug terminal and extends over a portion of the plug insulator. These boots prevent flash-over with resultant missing of the engine, even though a film is allowed to accumulate on the exposed portion of the plug porcelains. DO NOT mistake corona discharge for flash-over or a shorted insulator. Corona is a steady blue light appearing around the insulator, just above the shell crimp. It is the visible evidence of a high-tension field, and has no effect on ignition performance. Usually it can be detected only in the darkness. This discharge may repel dust particles, leaving a clear ring on the insulator just above the shell. This ring is sometimes mistakenly regarded as evidence that combustion gases have blown out between the shell and the insulator. SPARK PLUG SELECTION Spark plus must operate within a certain temperature range if they are to provide the performance and service life expected of them. The spark plug selected for an engine is based on the normal service for which the engine is designed. The spark plug may not perform satisfactorily under other-than-normal operating conditions. For almost-exclusively city driving, a spark plug 1 step higher in heat range might deliver a longer service life than the spark plug recommended for normal operation. Conversely, a spark plug rated 1 step colder will perform better for heavy loads or continual high-speed driving. There are three rules to follow when selecting spark plugs for an engine in good condition: - Select a plug with a specific heat range. - Should spark plug overheating occur, select a spark plug that is one heat range lower than the specified range. - If fouling is a problem, select a spark plug that is one step higher that the specified range. Page 1621 Lifter / Lash Adjuster: Service and Repair Fig. 13 Hydraulic Lifters & Retainer REMOVAL 1. Remove rocker arm cover and pushrods as described under ROCKER ARM & PUSHRODS 2. Remove intake manifold as described under INTAKE MANIFOLD. 3. Remove retainer-to-engine attaching bolts, retainer and restrictors, Fig. 13. 4. Remove lifters. Note lifter location when removing. Lifters must be installed in same bore. DISASSEMBLY 1. Depress pushrod seat with pushrod, remove seat retainer, then slowly release spring tension. 2. Remove pushrod seat and metering valve. 3. Invert lifter and tap on flat surface to remove plunger and plunger spring. 4. Remove check ball retainer by prying from plunger with small screwdriver. 5. Remove check ball spring and check ball. 6. Clean lifter components in solvent, keeping components for each lifter separate INSPECTION 1. Inspect lifter body for internal and external wear. Also inspect bottom for wear grooves and flat spots. 2. Inspect roller for free operation, flat spots and pitting. Replace lifter if roller is worn, pitted or cannot be freed up. 3. Inspect pushrod seat and replace lifter and pushrod if seat is scored or excessively worn. 4. Inspect check ball and replace lifter if ball is pitted or scored. Do not attempt to recondition lifter assembly by interchanging components from other lifters. If components are damaged or worn, lifter assembly should be replaced. ASSEMBLY Ensure lifter components are kept clean during assembly, as small particles of dirt or lint can cause lifter to fail. 1. Install check ball to the small hole in bottom of plunger. 2. Install check ball spring and retainer, over check ball, then press retainer into position in plunger with small screwdriver. 3. Install plunger spring to check ball retainer. 4. Align oil feed holes in lifter body and plunger, then install plunger into lifter body. 5. Fill lifter with SAE 10 oil and proceed as follows: a. Insert a 1/8 inch punch into plunger and press down solidly, then using a 1/16 inch punch, insert punch through oil holes to retain plunger down against plunger spring tension. b. Remove 1/8 inch punch and fill lifter with SAE 10 oil. 6. Install metering valve, pushrod seat and seat retainer. 7. Depress pushrod seat with pushrod and remove 1/16 inch punch from lifter body. Page 7403 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 8416 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 6211 Before fully seating the assembly on the Front Head, be sure the clutch coil terminals are in the proper location in relation to the compressor and that the three protrusions on the rear of the clutch coil align with the locator holes in the Front Head. 3. Install the rotor and bearing assembly retaining ring and reassemble the Clutch Plate and Hub assembly. Check to see that the clutch plate to clutch rotor air gap is 0.5-7.6mm (0.020-0.030"). Rotate the Pulley Rim and Rotor to be sure the Pulley Rim is rotating "in-line" and adjust or replace as required. 4. Tighten the pulley rim mounting screws to 11 N.m (100 in.lbs.) torque and lock the screw heads in place by bending screw head washer, similar to original crimp and lock bends on washers. Poly-Groove Drive Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. 2. Remove the pulley rotor and bearing assembly as described previously. Mark the location of the clutch coil terminals on the compressor. Engine - Hard Start Or No Start Fuel Pressure Pulsation Damper: All Technical Service Bulletins Engine - Hard Start Or No Start File In Section: 6E Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator. The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks. If the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description Qty 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty. use: Labor Op Description Labor Time Use Published Labor J 5590 Pump, Fuel R&R; Operation Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Page 4392 Fig. 4 Cross & Roller Type Universal Joints & Propeller Shaft Before disassembling any universal joint, examine the assembly carefully and note the position of the grease fitting (if used). Also, be sure to mark the yokes with relation to the propeller shaft so they may be reassembled in the same relative position. Failure to observe these precautions may produce rough vehicle operation which results in rapid wear and failure of parts, and place an unbalanced load on transmission, engine and rear axle. When universal joints are disassembled for lubrication or inspection, and the old parts are to be reinstalled, special care must be exercised to avoid damage to universal joint spider or cross and bearing cups. Some driveshafts use an injected nylon retainer to hold the bearing cups. When service is necessary, pressing the cups out will sheer the nylon retainer, Fig. 1. Replacement with the conventional steel snap ring type is then necessary, Fig. 2. Figs. 3 and 4 illustrate typical examples of universal joints of this type. They all operate on the same principle and similar service and replacement procedures may be applied to all. Fig. 5 Removing Bearing Cups From Yoke Disassembly 1. Place driveshaft into a vise using care not to damage it. 2. Remove snap rings (or retainer plates) that retain bearing cups in yoke and driveshaft. 3. Select a socket with an outside diameter slightly smaller than the bearing cup. Select another socket with an inside diameter slightly larger than the bearing cup. 4. Place the sockets at opposite ends of the yoke so that the smaller socket becomes a cup pusher and the larger socket becomes a cup receiver and reposition in vise as shown Fig. 5. Close vise jaws until both cups are free of yoke. Remove cups from the cross or spider and remove yoke. 5. If bearing cups will not come all the way out, close the vise until the cup in receiver socket protrudes from yoke as much as possible without using excessive force. Then remove from vise and place that portion of the cup which protrudes from yoke between vise jaws. Tighten vise to hold cup and drive yoke off with a soft hammer. 6. To remove opposite bearing cup from yoke, replace in vise with pusher socket in exposed cross journal and receiver socket over bearing cup, then tighten vise jaws to press cup through yoke into receiving socket. If bearing cup will not come all the way out, place protruding portion of cup between vise jaws, then tighten vise to hold cup while driving yoke off cup with soft hammer. 7. Turn spider or cross 1/4 turn and repeat procedure to press cups out of driveshaft. Page 3575 Ignition Coil: Description and Operation HEI Distributor With External Coil The distributor has an exterior ignition coil. The exterior coil is mounted remote from the distributor and is connected to the rotor through a high tension coil wire. The coil is built like a transformer with the winding surrounded by a laminated iron frame. It steps up battery voltage (12 volts) to high voltage (up to 35,000 volts). The primary circuit is energized when the ignition switch is in the "ON" position. When the ignition module breaks the circuit to ground, on the primary (negative side of coil) circuit, the magnetic field collapses, which induces high voltage in the secondary circuit, which finds its ground at the spark plug. Page 8677 Front Door Trim Panel Components Front Inner Panel Water Deflector Page 8367 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 1216 85-89 - 97104794 90-93 - 97104793 Adapter, Low Side: Part of Hose Asm. 0-rings: Receiver/dryer 85-91 - 94154048 92-93 - 94461700 Switch/pipe - 94461902 Suction hose: 85-86: 1.5L - 97104799; 1.6L - 97104800 90-93: 1.6L - 97104801; 1.8L - 97104803 B. General Information Several items affecting the performance and durability of the system should be considered: 1. Performance When performed properly, the retrofit from R-12 to R-134a will have minimal effect on the system's performance in most climatic conditions found in the United States and Canada. 2. Leakage Experience has shown that most leakage in an A/C system is due to leaks at the joints, or through a small leak in a hose, usually at the coupling. The R-134a molecules are smaller than R-12, and a small leak may result in a faster loss of refrigerant with R-134a. Because of this, it is very important to leak check all vehicles using the J 39400 leak detector, BEFORE the retrofit is performed, and repair any leaks found. "0" rings and hoses used in most GM vehicles are compatible with R-134a and do not need replacement during a retrofit. "0" rings or hoses installed in previous repairs may have been of non-compatible materials if GM parts were not used and will be more likely to deteriorate and leak than the original equipment materials. All "0" rings and hoses available through GMSP0 are compatible with R-134a. Remember that the normal policy is to replace the "0" rings whenever a joint is opened for any reason. 3. Desiccant You may have heard that the currently used desiccant in the accumulator is not compatible with R-134a. Extensive testing has shown that it is, in fact, suitable for use with R-134a, once it has been in service in an R-12 system. The accumulator in these models will not have to be changed during the retrofit procedure, unless the vehicle is more than 5 years old. Vehicles more than 5 years old should have the A/D replaced to add new desiccant for proper system drying. In the event that an accumulator/dryer (A/D) needs to be replaced on a retrofitted system in the future, only A/D's with XH-7 desiccant should be used. The service parts for the 1993 vehicles contain only XH-7 desiccant. The parts for the 1992 and older vehicles may contain either XH-5 or XH-7. Parts containing XH-7 can be identified (see Figure 1) by 1) an "A" printed on the top of the A/D; or 2) if there is a label on top of the A/D, there will be a square with an "A" inside; or 3) if there is a time code and date printed on top of the A/D just under the "Harrison" logo, the A/D contains XH-7. A/D's containing XH-5 can still be used on R-12 vehicles. 4. Improved Cooling Performance There have been service bulletins issued in the past with information improving the cooling performance of existing R-12 systems. These bulletins can also be used to improve the performance of retrofitted vehicles in high ambient temperature climates. 5. PAG or V5 Oil Compatibility Contrary to information published to date outside of General Motors, mineral oil and PAG or V5 oil ARE chemically compatible. The mineral oil left in the system after reclaiming the R-12 can remain in the system with no harmful effects. However, the mineral oil will not mix with the R-134a, and so will not circulate and perform its lubricating function. Testing has shown that most of the mineral oil will eventually collect in the Page 3323 Parts Information Parts are currently available from GMSPO. Page 5754 Suspension Strut / Shock Absorber: Technical Service Bulletins Suspension - Shock Absorber/Strut Replacement Guidlines File In Section: Warranty Administration Bulletin No.: 72-05-12 Date: January, 1998 WARRANTY ADMINISTRATION Subject: Replacement of Shock Absorbers and Struts Labor Operations E3800, E3801, E3807, E5800, E5801, E5807, E3850, E3851, E3857, E5750, E5751, and E5757 Models: All Past, Present, and Future Passenger Cars & Trucks The purpose of this bulletin is to provide retail and wholesale service personnel with enhanced service policies for the above listed subject labor operations. Service Management should make certain that all dealership personnel responsible for replacement of suspension components are familiar with GM Service Manual procedures. Effective with repair orders dated on or after January 15, 1998 the following must also be followed: - Shock absorber/strut assemblies are fluid filled components and will normally exhibit seepage. Seepage is defined as oil film or dust accumulation on the exterior of the shock housing. Shock absorber/strut assemblies are not to be replaced under warranty or seepage. - Defective shock absorber/strut assemblies will have a visible oil path or drip coming from the component. A visible oil path or drip coming from the shock absorber/strut assembly should be replaced as a defective component. - Only defective shock absorber/strut assemblies should be replaced. DO NOT replace pairs unless both are defective, unless otherwise instructed in the Service Manual and/or Service Bulletin. - Service Management approval is required on the repair order for replacement of struts or shocks in pairs. This approval includes noting the reason for replacement. Page 6090 Blower Motor Does Not Run In HI But Operates In Lo And/Or Med Blower Noise Page 7727 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 8636 PARTS INFORMATION: Pads are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Op. C-0152-RH C-0153-LH Use applicable labor time guide for labor hours. Page 1335 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Locations Horn Relay Installation Page 7437 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 7390 Figure 7 Figure 8 Figure 9 Figure 10 Page 6965 1). Record this measurement for reassemble purposes. This measurement will give the combined pinion bearing and seal pre-load. Also record the number of exposed threads beyond the flange nut on the pinion flange nut. 5. Remove the pinion flange nut and washer by using tool J 8614-01 to hold the pinion flange using a socket and driver. Discard existing pinion flange, nut, washer, and seal deflector (Figure 2). 6. Remove the pinion flange using tool J 8614-01, J 8614-02 and J 8614-03 (Figure 3) while using a suitable container to catch any fluid that may drain from the rear axle when removing the pinion flange. 7. Inspect the pinion oil seal for any signs of damage or contamination. If either condition exists, replace the pinion oil seal (P/N 26026792). Install or Connect (Figures 1, 2, and 3) 1. Apply a seal lubricant (GM P/N 1052497) to the outside of the pinion flange. 2. Install the pinion flange. Notice: DO NOT ATTEMPT TO HAMMER THE PINION FLANGE ONTO THE REAR AXLE PINION STEM AS IT MAY CAUSE DAMAGE TO THE PINION BEARINGS. 3. Install the washer and flange nut on the pinion stem shaft. Tighten ^ Hold the companion flange with J 8614-01 while tightening the flange nut on the pinion stem. ^ Tighten the pinion nut a little at a time, rotating the pinion occasionally to ensure proper bearing seating. Also, take frequent pinion bearing torque pre-load readings until the original torque value is obtained (Figure 2). Speedometer - Registers When Vehicle is Stationary Vehicle Speed Sensor: Customer Interest Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. Page 4320 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure that pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. When endplay is reduced to zero, check pinion bearing preload by rotating pinion with suitable torque wrench. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Specifications Heater Hose: Specifications Heater Hose Clamp Screw .................................................................................................................. ................................................... 1.7 Nm (15 in. lb.). Page 1055 5. Anytime the A/C system has been "opened" it should be properly evacuated before recharging. Page 351 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 1521 Page 1286 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7629 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 7606 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 4565 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Recall 99V193000: ABS 4WD Switch Defective 4WD Switch: All Technical Service Bulletins Recall 99V193000: ABS 4WD Switch Defective Description: Certain 4-wheel drive pickup trucks and sport utility vehicles equipped with ABS (antilock braking system) manufactured from September 1989 through August 1996. Under certain driving conditions the switch which signals the ABS system whether the vehicle is in 2-wheel or 4-wheel drive can malfunction causing increased stopping distances during ABS stops while in the two-wheel drive mode. If this occurred at a time when minimum stopping distance was required, a vehicle crash could occur without prior warning. Dealers will replace or repair the 4-wheel/2-wheel drive switch. The first phase of owner notification letters began May 31, 2000, with the last mailing completed by October 2000. Owners can contact Chevrolet at 1-800-222-1020 or GMC at 1-800-462-8782. Also contact the National Highway Traffic Safety Administration's Auto Safety Hotline at 1-888-DASH-2-DOT (1-888-327-4236). Page 1322 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 4887 Antilock Brake Module: Electrical Diagrams Fig. 7 Four Wheel Anti-lock Brake Wiring Circuit. Bravada, Astro/Safari & 2WD S/T Locations LH I/P Harness Wiring Connector C1 ECM Connector C1 Front Suspension - Squeaking Noise Suspension Spring ( Coil / Leaf ): All Technical Service Bulletins Front Suspension - Squeaking Noise Group Ref.: 3 - Steering/Suspension Bulletin No.: 463302 Date: August, 1994 SUBJECT: FRONT SUSPENSION SQUEAK (INSTALL SERVICE KIT INSULATORS FOR COIL SPRINGS) MODELS: 1992-94 CHEVROLET AND GMC TRUCK S PICKUPS (TWO-WHEEL DRIVE ONLY) CONDITION: Some owners may comment that a squeaking noise can be heard emanating from the front suspension area of their vehicle. This condition may be duplicated by jouncing the vehicle body in the front while it is parked. If the condition is not verified in this manner, road test the vehicle. CAUSE: The usual cause of this squeak is the contact between the coil spring and the upper frame pocket or control arm. The insulators installed in production between the coil spring and the control arms might deteriorate allowing metal to metal contact to occur. CORRECTION: To fix this condition, a Service Kit (P/N 15989719) has been released containing two newly designed insulators with the upper insulator having a nylon insert. Placement of the nylon insert into the rubber insulator is from the top. The insulator, along with the insert, goes on the top of the coil spring while the other insulator without the insert goes on the bottom of the coil spring. Two service kits will be necessary if both front coil springs are causing a noise. Vehicles built after the VIN breakpoints have a newly designed frame pocket for the front coil spring. SERVICE PROCEDURES: Page 5100 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 1938 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 6916 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 5435 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 4648 Brake Caliper: Service and Repair Installation For additional information see Installation Notes. See: Fundamentals and Basics Retracting Piston 1. Retract piston in caliper bore and position caliper over disc, lining up holes in caliper with holes in mounting bracket. If brake hose was not disconnected during removal, be sure not to kink it during installation. Caliper Mounting Bolts 2. Start mounting bolts through sleeves in inboard caliper ears and the mounting bracket, making sure ends of bolts pass under ears on inboard pad. NOTICE: If the caliper was removed for service, make sure it is installed on the correct knuckle. The caliper bleed screw should be positioned on top of caliper when assembled on vehicle. 3. Push mounting bolts through to engage holes in the outboard ears. Then thread mounting bolts into bracket. 4. Torque mounting bolts to 50 Nm (37 ft lb). Page 2232 Maximum fan speed (air flow and related fan noise) through the engine compartment is experienced under two conditions. 1. When the vehicle sits in an unused condition for several hours, the viscous fluid within the thermostatic fan clutch assembly migrates and fully engages the clutch of the fan. After a short drive, the viscous fluid will migrate to the storage area in the fan clutch and the fan clutch will slip, reducing the noise (roar of the fan). This is normal thermostatic fan clutch operation. 2. When the engine is running, and the air being drawn by the fan or pushed through the radiator from the vehicle movement reaches a high enough temperature, the fan clutch will fully engage the fan clutch, drawing additional air through the radiator to lower the engine coolant temperature and A/C refrigerant temperature. When the cooling fan clutch fully engages, fan noise increases (for example; this is the same as switching an electric household fan from low to high speed). Some customers have interpreted this sound increase to be an increase in the engine RPM due to transmission downshift, transmission slipping, or TCC cycling. As the engine coolant temperature decreases, the fan clutch will begin to slip, lowering the actual speed of the fan blade and the resultant sound. Service Procedure When diagnosing an intermittent transmission downshift, slip, or busy/cycling TCC, follow these steps: 1. Verify the transmission fluid level and the fluid condition. Refer to the Automatic Transmission sub-section of the appropriate Service Manual. 2. Test drive the vehicle under the conditions described by the customer (ambient temperature, engine coolant temperature, trailering, etc.). It may be necessary to partially restrict airflow to the radiator in order to raise the engine coolant temperature to match the customer's conditions. 3. Monitor the engine RPM and the engine coolant temperature using a scan tool. 4. Listen for an actual increase in the engine RPM. Use either the vehicle tachometer (if equipped), the Tech 2 RPM or transmission slip speed as an indicator, rather than just the sound. If the engine RPM display on the tachometer or the Tech 2 increases, verify the scan tool RPM and coolant temperature readings. If the noise increase is due to the engagement of the fan, the engine RPM will not increase and the engine coolant temperature will begin to decrease after the fan engages. As the fan runs, the engine coolant temperature will drop and the fan will disengage, reducing noise levels. The engine RPM will not decrease. This cycle will repeat as the engine coolant temperature rises again. If the above procedure shows the condition to be cooling fan-related, no further action is necessary. The vehicle should be returned to the customer and the condition explained. If the above procedure shows the condition to be other than cooling fan-related, refer to the Automatic Transmission sub-section of the appropriate Service Manual for transmission diagnosis information. The following information regarding the operation of the engine cooling fan should be photocopied and given to the customer. Intermittent Transmission Downshift All light duty trucks are equipped with a thermostatic engine cooling fan. This fan is designed to provide greater fuel efficiency and quieter operation than a standard fan. These benefits are possible through the addition of a thermostatic clutch to the fan drive. When the engine is cool (it the engine has been run in the last few hours), the clutch allows the fan to "slip" or turn at a speed slower than the engine. By turning at a slower speed, the fan uses less horsepower, which saves fuel, and is quieter. When the engine temperature reaches a preset temperature or if the engine has not been run for several hours, the fan "engages" and turns at the same speed as the engine. "Engagement" of the fan provides increased airflow through the radiator to cool the engine. As the airflow increases, fan operation becomes clearly audible. This increase in noise can easily be mistaken for an increase in engine RPM and may be incorrectly blamed on the automatic transmission. When operating an unloaded vehicle in cooler ambient temperatures, the thermostatic clutch usually won't fully engage. However, if the vehicle is pulling a trailer, is heavily loaded or is operated at high ambient temperatures, the thermostatic fan clutch may cycle on and off as the engine coolant temperature rises and falls. The sound of fan operation under the conditions described above is a sign that the cooling system on your vehicle is working correctly. Replacement or modification of the cooling system or the transmission parts will not change or reduce the noise level. Attempts to reduce this noise may cause you, the customer, to believe that your vehicle is not reliable and will inconvenience you by causing your vehicle to be out of service. Locations Steering Column Locations Vehicle Speed Sensor/Transducer - Cruise Control: Locations Electronic Control Module (ECM) & Vehicle Speed Sensor Buffer (DRAC) Behind RH Side Of I/P Page 7570 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 5225 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Specifications Brake Drum: Specifications Original Drum Size 9.50 in Maximum Refinish 9.560 in Discard 9.590 in Page 6069 Air Door Cable: Adjustments Defroster Cable Adjustment Control Cable ADJUST 1. Remove the retainer from the lever. 2. Remove the cable. 3. Bend the cable to lengthen or shorten. 4. Reattach the cable to the lever and move the control lever in the full range of its travel and listen for the defroster door opening and closing. Adjust the cable as necessary and install the retainer. Page 8264 Figure 7 Figure 8 Figure 9 Figure 10 Diagram Information and Instructions Trailer Adapter Kit: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 5168 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Cooling - Cold Start Fan Noise Higher Than Normal Fan Clutch: Customer Interest Cooling - Cold Start Fan Noise Higher Than Normal Number: 92-118-6B Section: 6B Date: FEB. 1992 Corporate Bulletin No.: 166203 ASE No.: A8 Subject: COLD START FAN NOISE Model and Year: 1988-92 S/T TRUCKS WITH 4.3L ENGINES Owners of some 1988-1992 S/T vehicles equipped with a 4.3L engine (RPO LB4 or L35) and air conditioning (RPO C60) may experience higher than normal fan noise upon oold start up. This condition may be due to incorrect engagement of the fan clutch. The condition may be corrected by installing a revised fan clutch (P/N 15672779). Vehicles built after the following VIN Breakpoints have the new fan clutch installed in production: Plant VIN Moraine 1GNDT13Z3N2151684 Shreveport 1GCCS19Z3N8156864 Pontiac West 1GNCS18Z2N0125676 SERVICE PROCEDURE: Refer to section 6B1 "FAN/FAN CLUTCH REPLACEMENT" in the appropriate S/T Service Manual for removal and installation of the fan clutch. Page 4003 Transmission Speed Sensor: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Page 8517 Symbol Identification Page 7332 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 8777 Fig. 10 Windshield Wiper Switch Removal (Rear) REAR Refer to Fig. 10, for wiper switch replacement. 1. Disconnect battery ground cable. 2. Remove switch trim plate and screws from instrument panel. 3. Disconnect electrical connector, then remove switch. 4. Reverse procedure to install. Page 1304 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Locations CMFI Assembly Parts Identification Page 2428 Electronic Control Module Page 4578 Symbol Identification Page 8215 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Cooling System, A/C - Aluminum Heater Cores/Radiators Heater Core: Technical Service Bulletins Cooling System, A/C - Aluminum Heater Cores/Radiators INFORMATION Bulletin No.: 05-06-02-001A Date: July 16, 2008 Subject: Information On Aluminum Heater Core and/or Radiator Replacement Models: 2005 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2003-2005 HUMMER H2 Supercede: This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 05-06-02-001 (Section 06 - Engine/Propulsion System). Important: 2004-05 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX-COOL(R). Refer to the flushing procedure explained later in this bulletin. The following information should be utilized when servicing aluminum heater core and/or radiators on repeat visits. A replacement may be necessary because erosion, corrosion, or insufficient inhibitor levels may cause damage to the heater core, radiator or water pump. A coolant check should be performed whenever a heater core, radiator, or water pump is replaced. The following procedures/ inspections should be done to verify proper coolant effectiveness. Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if the radiator cap or surge tank cap is removed while the engine and radiator are still hot. Important: If the vehicle's coolant is low, drained out, or the customer has repeatedly added coolant or water to the system, then the system should be completely flushed using the procedure explained later in this bulletin. Technician Diagnosis ^ Verify coolant concentration. A 50% coolant/water solution ensures proper freeze and corrosion protection. Inhibitor levels cannot be easily measured in the field, but can be indirectly done by the measurement of coolant concentration. This must be done by using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale), or equivalent, coolant tester. The Refractometer uses a minimal amount of coolant that can be taken from the coolant recovery reservoir, radiator or the engine block. Inexpensive gravity float testers (floating balls) will not completely analyze the coolant concentration fully and should not be used. The concentration levels should be between 50% and 65% coolant concentrate. This mixture will have a freeze point protection of -34 degrees Fahrenheit (-37 degrees Celsius). If the concentration is below 50%, the cooling system must be flushed. ^ Inspect the coolant flow restrictor if the vehicle is equipped with one. Refer to Service Information (SI) and/or the appropriate Service Manual for component location and condition for operation. ^ Verify that no electrolysis is present in the cooling system. This electrolysis test can be performed before or after the system has been repaired. Use a digital voltmeter set to 12 volts. Attach one test lead to the negative battery post and insert the other test lead into the radiator coolant, making sure the lead does not touch the filler neck or core. Any voltage reading over 0.3 volts indicates that stray current is finding its way into the coolant. Electrolysis is often an intermittent condition that occurs when a device or accessory that is mounted to the radiator is energized. This type of current could be caused from a poorly grounded cooling fan or some other accessory and can be verified by watching the volt meter and turning on and off various accessories or engage the starter motor. Before using one of the following flush procedures, the coolant recovery reservoir must be removed, drained, cleaned and reinstalled before refilling the system. Notice: ^ Using coolant other than DEX‐COOL(R) may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50,000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX‐COOL(R) (silicate free) coolant in your vehicle. ^ If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost would not be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core and other parts. Page 8613 3. Regulator lift arm roller to the window mount sash. 4. Wire harness to the motor. 5. Water deflector. 6. Armrest bracket. 7. Door trim panel. 8. Battery ground cable. Page 8406 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 2890 ECM Connector C2 Page 4727 4. Open the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (figure 2). Page 1305 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 7791 Door Switch: Locations Door Jamb Switch, LH Rear In LH B-Pillar Page 8419 Parking Lamp: Electrical Diagrams Rear Park And Marker Lamps Page 2064 Fuel Pressure Test Port: Service and Repair Fuel Pressure Connection CLEAN Area around fuel pressure connection with GM X-30A or equivalent. REMOVE OR DISCONNECT - Negative battery terminal. - Relieve fuel system pressure. - Fuel pressure connection and seal. Discard seal. INSTALL OR CONNECT - New seal on fuel pressure connection. - Fuel pressure connection in fuel rail. Tighten Fuel pressure connection assembly to 10.0 N-m (88 lb. in.). - Tighten fuel filler cap. - Negative battery terminal. INSPECT - Turn ignition switch to the "ON" position for two seconds, then turn to the "OFF" position for ten seconds. Again turn to the "ON" position, and check for fuel leaks. NOTE Any time the battery is disconnected, the programmed position of the IAC valve pintle is lost, and replaced with a default value. To return the IAC valve pintle to the correct position, perform the following procedure: - Disconnect negative battery for at least ten seconds to clear control module memory. (Ensure ignition is "OFF".) - Reconnect negative battery cable. - "START" engine and allow engine to reach operating temperature. Check for proper idle operation. Page 6175 1. Hex nut using a 19 mm socket. Removing The Clutch Plate 2. Clutch front plate using J 37825. - Align the puller center bolt to the compressor shaft. - Thumb tighten the three puller bolts into the threaded holes. - Turn the center bolt to the right with the socket wrench until the front plate is loosened. Removing The Shaft Key 3. Shaft key (27) by lightly tapping it loose with a slot screw driver and hammer. Removing The Internal Snap Ring 4. Internal bearing snap ring (4) with J 4245. 5. External front housing snap ring with J 6435. 6. Rotor pulley assembly. Page 6571 Voltmeter Is Inaccurate Diagram Information and Instructions Starter Solenoid: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Vehicle - Engine Crankcase and Subsystems Flushing Info. Continuously Variable Transmission/Transaxle: All Technical Service Bulletins Vehicle - Engine Crankcase and Subsystems Flushing Info. INFORMATION Bulletin No.: 04-06-01-029E Date: April 29, 2010 Subject: Unnecessary Flushing Services, Additive Recommendations and Proper Utilization of GM Simplified Maintenance Schedule to Enhance Customer Service Experience Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and add information about the proper transmission flush procedure. Please discard Corporate Bulletin Number 04-06-01-029D (Section 06 - Engine/Propulsion System). An Overview of Proper Vehicle Service General Motors is aware that some companies are marketing tools and equipment to support a subsystem flushing procedures. These dedicated machines are in addition to many engine oil, cooling system, fuel system, A/C, transmission flush and steering system additives available to the consumer. GM Vehicles under normal usage do not require any additional procedures or additives beyond what is advised under the former Vehicle Maintenance Schedules or the current Simplified Maintenance Schedules. Do not confuse machines available from Kent-Moore/SPX that are designed to aid and accelerate the process of fluid changing with these flushing machines. Engine Crankcase Flushing General Motors Corporation does not endorse or recommend engine crankcase flushing for any of its gasoline engines. Analysis of some of the aftermarket materials used for crankcase flushing indicate incompatibility with GM engine components and the potential for damage to some engine seals and bearings. Damage to engine components resulting from crankcase flushing IS NOT COVERED under the terms of the New Vehicle Warranty. GM Authorized Service Information: Detailed, Descriptive, and Complete If a specific model vehicle or powertrain need is identified, GM will issue an Authorized Service Document containing a procedure and, if required, provide, make available, or require the specific use of a machine, tool or chemical to accomplish proper vehicle servicing. An example of this is fuel injector cleaning. Due to variation in fuel quality in different areas of the country, GM has recognized the need for fuel injector cleaning methods on some engines, though under normal circumstances, this service is not part of the maintenance requirements. GM has published several gasoline fuel injector cleaning bulletins that fully outline the methods to be used in conjunction with GM Part Numbered solutions to accomplish proper and safe cleaning of the fuel injectors with preventative maintenance suggestions to maintain optimum performance. You may refer to Corporate Bulletin Numbers 03-06-04-030 and 04-06-04-051 for additional information on this subject. Subsystem Flushing Flushing of A/C lines, radiators, transmission coolers, and power steering systems are recognized practices to be performed after catastrophic failures or extreme corrosion when encountered in radiators. For acceptable A/C flushing concerns, refer to Corporate Bulletin Number 01-01-38-006. This practice is NOT required or recommended for normal service operations. The use of external transmission fluid exchange or flush machines is NOT recommended for the automatic or manual transmission. Use of external machines to replace the fluid may affect the operation or durability of the transmission. Transmission fluid should only be replaced by draining and refilling following directions in SI. Refer to Automatic/Manual Transmission Fluid and Filter Replacement. Approved Transmission Flushing Tool (Transmission Cooler Only) The Automatic Transmission Oil Cooler Flush and Flow Test Tool is recommended for GM vehicles. Refer to Transmission Fluid Cooler Flushing and Flow Test in SI using the J 45096. Service Is Important to You and Your Customer General Motors takes great pride in offering our dealerships and customers high quality vehicles that require extremely low maintenance over the life of the vehicle. This low cost of ownership builds repeat sales and offers our customers measurable economy of operation against competing vehicles. Campaign - 02-313 Stop Delivery Notice Update Fuel Level Sensor: All Technical Service Bulletins Campaign - 02-313 Stop Delivery Notice Update ** ADMINISTRATIVE MESSAGE 01-277 CREATED ON 9/5/91 AT PAGE 1 OF 1 TO: ALL CHEVROLET DEALERS SUBJECT: STOP DELIVERY NOTICE 1992 S/T TRUCKS THIS IS WITH FURTHER REFERENCE TO THE 1992 S/T TRUCK STOP DELIVERY DCS ADMIN MESSAGE 01-258 DATED 8/22/91 SENT TO ALL CHEVROLET DEALERS. SELECT DEALERS WERE ADVISED IN DCS MESSAGE 02-313 DATED 9/5/91 OF PRODUCT CAMPAIGN 92C02 FUEL LEVER SENDER ARM/TANK INTERFERENCE. THIS DCS INCLUDED INVOLVED DEALER CODES AND INVOLVED VIN'S. ANY DEALER NOT RECEIVING DCS ADMIN MESSAGE 02-313 HAS NO INVOLVED VEHICLES ASSIGNED AND VIN'S WHICH FALL WITHIN THE ORIGINAL VIN RANGES LISTED BELOW ARE RELEASED FROM THE STOP DELIVERY. ASSEMBLY PLANT STARTING VIN ENDING VIN PONTIAC WEST N0100014 N0101228 MORAINE N2100052 N2101700 SHREVEPORT N8100014 N8101560 PLEASE COMMUNICATE THIS INFORMATION TO ALL DEALERSHIP MANAGEMENT IMMEDIATELY UPON RECEIPT. Page 5271 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 7828 Fuel Gage Is Inaccurate Page 7597 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Diagram Information and Instructions Brake Vacuum Release Valve: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Diagram Information and Instructions Clutch Switch: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 5476 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 4495 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Locations Horn Switch: Locations Part Of Multi-Function Switch Contaminated R12 Refrigerant - Testing & Handling Refrigerant: Technical Service Bulletins Contaminated R12 Refrigerant - Testing & Handling FILE IN SECTION: 1 - HVAC BULLETIN NO.: 53-12-05 DATE: May, 1995 SUBJECT: Contaminated R12 Refrigerant Testing and Handling MODELS: 1994 and Prior Passenger Cars and Trucks with R12 A/C Systems The J 39851 "PureGuard" R12 refrigerant monitor was recently shipped to all GM dealers as an essential tool to test R12 refrigerant. Dealers are strongly urged to install this protective device on their ACR3 or other R12 recovery equipment immediately. The PureGuard is easily installed on any recovery cart (20 minutes), requires no recovery cart modifications, is fully automatic (no training required) and does not increase the time required to perform normal A/C service procedures. Proper use of this tool can: ^ Prevent damage to your R12 recovery/recycling equipment. ^ Prevent contamination of previously recovered R12 in the recovery tank. ^ Prevent loss of your recovered R12 as contaminated refrigerant will activate automatic air purge system. ^ Prevent the spread of contaminated R12 to other vehicles you service. If your dealership has multiple R12 recovery stations which are not protected, use the PureGuard to check the refrigerant in these recovery tanks for contamination at least once each week. Simply connect the PureGuard blue service hose (that would normally be connected to the vehicle low side service port) to the red or vapor side of any recovery cart tank and run the test. It is also important to check a tank containing recovered/recycled material for purity before installation on your charging equipment. Even new R12 refrigerant purchased from sources other than GM should be tested for contamination prior to use. Sources of Contaminated R12 Refrigerant Since refrigerant testing has not been a standard practice in the mobile A/C repair industry, the amount of R12 refrigerant contamination is unknown. As R12 prices rise and supplies are depleted, it is anticipated that contaminated R12 refrigerant may become more prevalent from the following as well as other sources: ^ The use of R12 refrigerant substitutes without installation of unique service fittings and proper identification labeling. ^ Improper use of R12 substitutes, such as topping off R12 systems with R134a or other refrigerants available to "do-it-yourselfers". ^ Poor quality or contaminated new or reprocessed R12 refrigerant. R12 can and should continue to be used to service vehicles built with R12 as long as it is available. Combining any refrigerant with R12 results in a refrigerant mixture which cannot be used in an A/C system. R134a is the only substitute refrigerant approved by GM and should only be used when the appropriate retrofit service bulletin procedures are explicitly followed. Use of any other substitute refrigerant requires the purchase of additional dedicated recovery, recycling (if applicable) and charging equipment to service each substitute refrigerant used. However, you should know that the Environmental Protection Agency (EPA) has listed several products as acceptable replacements for R12 mobile A/C systems under the Significant New Alternatives Policy (SNAP). Some of these products are: R134a, R401c (a DuPont refrigerant blend) and FRIGC (another refrigerant blend). It is important to understand that the SNAP program only considers the health, safety and environmental characteristics of a chemical. It does not test for A/C system cooling performance or durability. That judgment is deferred to the vehicle manufacturer. Use of any R12 refrigerant substitute without dedicated service equipment, unique fittings, labels and refrigerant testing prior to recovery, could result in contamination of the R12 supply and the loss of the R12 recycling program. What To Do When Contamination is Detected Repeat the test to verify contaminated refrigerant is present. Clear the PureGuard following the instructions listed on the face panel, then perform a second test to verify that the vehicle A/C system contains contaminated or mixed refrigerant. Contact the vehicle owner to advise that previous A/C system repairs were apparently performed with an R12 refrigerant substitute. Suggest the owner Page 5123 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 4246 Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 1. Remove shim and disc pack from side gear, keeping components in order. 2. Inspect discs and guide clips and replace as needed. 3. Inspect side gear and shim. If either component is damaged or excessively worn, differential assembly must be replaced. If gear hub is scored or abnormally worn, inspect corresponding bore in case. If case bore is damaged or oversize, differential assembly must be replaced. 4. Assemble eared and splined discs onto side gear hub, starting with eared disc as shown in Fig. 8. If original disc pack is used, ensure that discs are installed in original position. Page 7436 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 4807 Wheel Cylinder: Service and Repair Rebuild For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Fig. 8 Disassembled View Of Wheel Cylinder (typical) 1. Remove boots, pistons, springs and cups from the wheel cylinder. 2. Clean all parts with brake fluid. 3. Inspect cylinder bore. A scored bore may be honed as long as the diameter is not increased by more than 0.127 mm (0.005 inch). Replace worn or damaged parts as necessary. 4. Ensure hands are clean before proceeding with assembly. Lubricate cylinder wall and rubber cups with brake fluid, then install springs, cups, pistons and boots in housing. 5. Install wheel cylinder. Page 8061 Speedometer Head: Testing and Inspection The following material covers only that service on speedometers which is feasible to perform. Repairs on the units themselves are not included as they require special tools and extreme care when making repairs and adjustments that only an experienced speedometer technician should attempt. The speedometer has two main parts-the speedometer head and the speedometer drive cable. When the speedometer fails to indicate speed or mileage, check the cable or cable housing for cracks or breaks. SPEEDOMETER CABLE Most cables are broken due to lack of lubrication, or a sharp bend or kink in the housing. A cable might break because of the speedometer head mechanism binds. In such cases, the speedometer head should be repaired or replaced before a new cable or housing is installed. A ``jumpy'' pointer condition, together with a scraping noise, is due, in most instances, to a dry or kinked speedometer cable. The kinked cable rubs on the housing and winds up, slowing down the pointer. The cable then unwinds and the pointer ``jumps.'' To check for kinks, remove the cable, lay it on a flat surface and twist one end with the fingers. If it turns over smoothly the cable is not kinked. But if part of the cable flops over as it is twisted, the cable is kinked and should be replaced. LUBRICATION The speedometer cable should be lubricated with special cable lubricant. Fill the ferrule on the upper end of the housing with the cable lubricant. Insert the cable in the housing, starting at the upper end. Turn the cable around carefully while feeding it into the housing. Repeat filling the ferrule except for the last six inches of cable. Too much lubricant at this point may cause the lubricant to work into the speedometer head. INSTALLING CABLE During installation, if the cable sticks when inserted in the housing and will not go through, the housing is damaged inside or kinked. Be sure to check the housing from end to end. Straighten any sharp bends by relocating clamps or elbows. Replace housing if badly kinked or broken. Position the cable and housing so that they lead into the head as straight as possible. Check the new cable for kinks before installing it. Use wide, sweeping, gradual curves where the cable comes out of the transmission and connects to the head so the cable will not be damaged during installation. Arrange the housing so it does not lean against the engine because heat from the engine may dry out the lubricant. If inspection indicates that the cable and housing are in good condition, yet pointer action is erratic, check the speedometer head for possible binding. The speedometer drive pinion should also be checked. If the pinion is dry or its teeth are stripped, the speedometer may not register properly. Locations CMFI Assembly Parts Identification Page 5380 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 5730 Page 7181 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 8507 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Page 7475 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 1661 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 6751 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 8558 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 8071 Temperature Gage Indicates Cold All The Time Page 2588 Vehicle Speed Sensor: Description and Operation 2 Wheel Drive (Manual Transmission) VSS 2WD Manual Transmission 2 Wheel Drive (Automatic Transmission) VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 4 Wheel Drive or All Wheel Drive VSS 4WD Or AWD PURPOSE The Vehicle Speed Sensor (VSS) provides information to the control module for control of: Transmission Torque Converter8Clutch (TCC) - Speedometer - Odometer Page 345 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 7673 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 8001 Door Switch: Locations Door Jamb Switch, LH Front In LH A-Pillar Specifications Manifold Pressure/Vacuum Sensor: Specifications Voltage 3.6 to 5.2 V at 1000 to 2000 ft 3.5 to 5.1 V at 2000 to 3000 ft 3.3 to 5.0 V at 3000 to 4000 ft 3.2 to 4.8 V at 4000 to 5000 ft 3.0 to 4.6 V at 5000 to 6000 ft 2.9 to 4.5 V at 6000 to 7000 ft 2.8 to 4.3 V at 7000 to 8000 ft 2.6 to 4.2 V at 8000 to 9000 ft 2.5 to 4.0 V at 9000 to 10000 ft Page 7678 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 792 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 5393 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 1345 Relay Box: Electrical Diagrams Convenience Center (without Digital Cluster) Page 7428 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Tires - Slipping on Rim Wheels: All Technical Service Bulletins Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Page 6672 Symbol Identification Page 4306 1). Record this measurement for reassemble purposes. This measurement will give the combined pinion bearing and seal pre-load. Also record the number of exposed threads beyond the flange nut on the pinion flange nut. 5. Remove the pinion flange nut and washer by using tool J 8614-01 to hold the pinion flange using a socket and driver. Discard existing pinion flange, nut, washer, and seal deflector (Figure 2). 6. Remove the pinion flange using tool J 8614-01, J 8614-02 and J 8614-03 (Figure 3) while using a suitable container to catch any fluid that may drain from the rear axle when removing the pinion flange. 7. Inspect the pinion oil seal for any signs of damage or contamination. If either condition exists, replace the pinion oil seal (P/N 26026792). Install or Connect (Figures 1, 2, and 3) 1. Apply a seal lubricant (GM P/N 1052497) to the outside of the pinion flange. 2. Install the pinion flange. Notice: DO NOT ATTEMPT TO HAMMER THE PINION FLANGE ONTO THE REAR AXLE PINION STEM AS IT MAY CAUSE DAMAGE TO THE PINION BEARINGS. 3. Install the washer and flange nut on the pinion stem shaft. Tighten ^ Hold the companion flange with J 8614-01 while tightening the flange nut on the pinion stem. ^ Tighten the pinion nut a little at a time, rotating the pinion occasionally to ensure proper bearing seating. Also, take frequent pinion bearing torque pre-load readings until the original torque value is obtained (Figure 2). Page 5432 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Tires (Front) - Irregular Wear Tires: All Technical Service Bulletins Tires (Front) - Irregular Wear Number: 91-26-3E Section: 3E Date: June 1990 Corp. Bulletin No: 053501 Subject: FRONT TIRE WEAR Model and Year: 1982-91 LIGHT DUTY TRUCKS (REAR WHEEL DRIVE) THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-12-3E. THE KILOMETERS HAVE BEEN TRANSLATED INTO MILES. ALL COPIES OF 91-12-3E SHOULD BE DISCARDED. Rear wheel drive trucks, equipped with All Season and/or On-Off road tires may exhibit irregular wear of; the front tires. Small amounts of irregular wear is considered normal and is not necessarily a result of incorrect alignment. Incorrect alignment (especially toe) may result in premature wear of the front tires, however agressive cornering may also have a similar effect. Drive axle tires are much less prone to irregular wear, therefore they should not be considered for comparison of wear to non-drive axle tires. The rate of irregular wear is also dependent upon the depth of tread. New tires are more prone to irregular wear, so it is essential that tires are rotated at the proper intervals to normalize the wear. Engine - Drive Belt Misalignment Diagnostics Drive Belt: Technical Service Bulletins Engine - Drive Belt Misalignment Diagnostics INFORMATION Bulletin No.: 08-06-01-008A Date: July 27, 2009 Subject: Diagnosing Accessory Drive Belt / Serpentine Belt Noise and Availability and Use of Kent-Moore EN-49228 Laser Alignment Tool - Drive Belt Models: 2010 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add a model year and update the Tool Information. Please discard Corporate Bulletin Number 08-06-01-008 (Section 06 - Engine). Background Several aftermarket companies offer laser alignment tools for accessory drive systems that can be very helpful in eliminating drive belt noise as a result of misaligned pulleys. Typically pricing ranges from $160 - $200. EN-49228 Laser Alignment Tool - Drive Belt The GM Tool program has now made available a competitive, simple to use and time-saving laser tool to assist in achieving precise alignment of the drive belt pulleys. This optional tool removes the guesswork from proper pulley alignment and may serve to reduce comebacks from: - Drive Belt Noise - Accelerated Drive Belt Wear - Drive Belt Slippage Instructions The instructions below are specific only to the truck Gen IV V-8 family of engines. These instructions are only for illustrative purposes to show how the tool may be used. Universal instructions are included in the box with the Laser Alignment Tool - Drive Belt. Caution - Do not look directly into the beam projected from the laser. - Use caution when shining the laser on highly polished or reflective surfaces. Laser safety glasses help reduce laser beam glare in many circumstances. - Always use laser safety glasses when using the laser. Laser safety glasses are not designed to protect eyes from direct laser exposure. 1. Observe and mark the serpentine belt orientation. Page 2366 RH Front Side Of Engine. RH Side Of Engine Block Applicable to: 1991-92 4.3L/V6-262 Engine, Except Bravada Page 8177 Door Switch: Locations RH Rear Door Jamb Switch In RH B-Pillar Page 5078 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Specifications Condenser HVAC: Specifications Evaporator Tube-to-Condenser .............................................................................................................................................................. 17 Nm (13 ft. lbs.). Condenser Mounting Bolt .................................................................................................................... ................................................ 1.4 Nm (12 in. lbs.). Refrigerant Hose-to-Condenser .............................................................................................................................................................. 24 Nm (18 ft. lbs.). Page 8131 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Symptom Related Diagnostic Procedures Air Door Actuator / Motor: Symptom Related Diagnostic Procedures Airflow Only From Floor And Defrost Registers With Control In Any Position Incorrect Airflow With Control In One Position Without A/C If the "Functional Test" or other diagnosis indicates improper air delivery or a failure to shift modes when the mode lever is moved, check the attachment of the affected control cable at the heater module. Be sure the cable loop is connected to the crank pin and the cable sheath is retained. If the cause of the problem is not discovered, disconnect the control cable at the crank pin and check the air control valve travel and effort. If there is proper valve travel and effort, check the control cable travel at the heater module end while moving the mode lever. If the cable end doesn't move, check for a broken cable or control assembly part and for an unattached cable end at the control assembly. Also, check for a sharp kink in the control cable sheath that could cause severe binding. Page 7792 Door Switch: Locations RH Front Door Jamb Switch In RH A-Pillar Diagram Information and Instructions Tape Player: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Tires - Slipping on Rim Wheels: Customer Interest Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Page 4739 Brake Bleeding: Service and Repair Master Cylinder Bleeding THIS PROCEDURE CAN BE PERFORMED WITH MASTER CYLINDER ON OR OFF VEHICLE. 1. Disconnect brake lines at master cylinder, if necessary. 2. Connect suitable lengths of brake lines to master cylinder and immerse other ends of lines in master cylinder reservoirs. 3. Apply master cylinder pushrod or brake pedal with full strokes until air bubbles have disappeared in reservoirs. It may require 20-30 applications to fully eliminate air bubbles. 4. Remove bleeding lines from master cylinder, then install master cylinder on vehicle, if necessary, and connect brake lines. 5. Fill the reservoir. Normal bleeding procedures should be followed after the master cylinder is installed. For additional information see Bench Bleeding Notes. See: Brake Master Cylinder/Fundamentals and Basics Page 6896 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 5482 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 2957 allowing the control module to make adjustments for different altitudes. The control module uses the MAP sensor to control fuel delivery and ignition timing. Test Description: Numbers below refer to circled numbers on the diagnostic chart. Important ^ Be sure to use the same diagnostic test equipment for all measurements. 1. Checks MAP sensor output voltage to the control module. This voltage, without engine running, represents a barometer reading to the control module. ^ When comparing Tech 1 "Scan" readings to a known good vehicle, it is important to compare vehicles that use a MAP sensor having the same color insert or having the same "Hot Stamped" number. 2. Applying 34 kPa (10" Hg) vacuum to the MAP sensor should cause the voltage to change. Subtract second reading from the first. Voltage value should be greater than 1.5 volts. Upon applying vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicated a faulty sensor. 3. Check vacuum hose to sensor for leaking or restriction. Be sure that no other vacuum devices are connected to the MAP hose. NOTE: Make sure electrical connector remains securely fastened. 4. Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connection. Output changes greater than .1 volt indicates a bad connector or connection. If OK replace sensor. Wiring Diagram For Code 33 - MAP Sensor Circuit (Signal Voltage High - Low Vacuum) ECM Circuit MAP Sensor Circuit (PCM) PCM Circuit Page 8400 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7340 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 7701 Audible Warning Device: Testing and Inspection Troubleshooting Hints 1. Check condition of IGN/GAU Fuse. 2. Check condition of STOP-HAZ Fuse. Page 3059 Vehicle Speed Sensor: Description and Operation 2 Wheel Drive (Manual Transmission) VSS 2WD Manual Transmission 2 Wheel Drive (Automatic Transmission) VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 4 Wheel Drive or All Wheel Drive VSS 4WD Or AWD PURPOSE The Vehicle Speed Sensor (VSS) provides information to the control module for control of: Transmission Torque Converter8Clutch (TCC) - Speedometer - Odometer Drivetrain - Recommended Axle Lubricant Fluid - Differential: Technical Service Bulletins Drivetrain - Recommended Axle Lubricant File In Section: 0 - General Information Bulletin No.: 76-02-02A Date: October, 1998 INFORMATION Subject: Recommended Axle Lubricant Models: 1999 and Prior Rear Wheel Drive Passenger Cars, Light and Medium Duty Trucks, and Four Wheel Drive Vehicles This bulletin is being revised to add the 1998 and 1999 Model Years and add Vehicle Line and Recommended Axle Lubricant Information. Please discard Corporate Bulletin Number 76-02-02 (Section 0 - General Information). The following tables provide the latest information on recommended axle lubricant. Page 2608 Throttle Position Sensor: Description and Operation TP Sensor Throttle Position Sensor (TPS) PURPOSE The Throttle Position Sensor (TPS) is a non-adjustable potentiometer that senses throttle angle and relays the information to the control module. This input to the control module is used to control the fuel system and most of the control module outputs. CONSTRUCTION The TPS has internally three circuits. One to ground, the other from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage . As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). OPERATION As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation movement to the TP sensor. A potentiometer (variable resistor) within the Throttle Position (TP) sensor assembly changes its resistance in proportion to throttle movement. If the TP sensor senses a Wide Open Throttle (WOT) a voltage signal indicating this condition is sent to the control module. The control module then increases the injector base pulse width, permitting increased fuel flow. LOCATION The non-adjustable Throttle Position (TP) sensor, is mounted on the side of the throttle body opposite the throttle lever assembly. Electrical Specifications Throttle Position Sensor: Electrical Specifications The throttle position sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Page 7691 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 5542 Verify Original Equipment Condition of the Vehicle - Verify that Original Equipment Tires and Wheels or Official GM Accessory Tires and Wheels are on the vehicle. - Verify that aftermarket suspension "Lift" or "Lowering" Kits or other suspension alterations have NOT been done to the vehicle. - Check for accidental damage to the vehicle; for example, severe pothole or curb impacts, collision damage that may have affected the wheel alignment of the vehicle; e.g., engine cradles, suspension control arms, axles, wheels, wheel covers, tires may show evidence of damage/impact. - Check to be sure vehicle has seen "Normal Use" rather than abuse; e.g., very aggressive driving may show up by looking at the tires and condition of the vehicle. - Check for other additional equipment items that may significantly affect vehicle mass such as large tool boxes, campers, snow plow packages (without the snowplow RPO), etc., especially in trucks and cutaway/incomplete vehicles. Significant additional mass can affect trim height and wheel alignment of the vehicle and may necessitate a customer pay wheel alignment when placed semi-permanently in the vehicle (Upfitter instructions are to realign the vehicle after placement of these types of items. (This typically applies to trucks and incomplete vehicles that can be upfit with equipment such as the above.) Customer Concerns, "Normal Operation" Conditions and "Mileage Policy" Possible Concerns The following are typical conditions that may require wheel alignment warranty service: 1. Lead/Pull: defined as "at a constant highway speed on a typical straight road, the amount of effort required at the steering wheel to maintain the vehicle's straight heading." Important Please evaluate for the condition with hands-on the steering wheel. Follow the "Vehicle Leads/Pulls" diagnostic tree located in SI to determine the cause of a lead/pull concern. Lead/Pull concerns can be due to road crown or road slope, tires, wheel alignment or even in rare circumstances a steering gear issue. Lead/pull concerns due to road crown are considered "Normal Operation" and are NOT a warrantable condition -- the customer should be advised that this is "Normal Operation." Important Some customers may comment on a "Lead/Pull" when they hold the steering wheel in a level condition. If so, this is more likely a "steering wheel angle" concern because the customer is "steering" the vehicle to obtain a "level" steering wheel. 2. Steering wheel angle to the left or right (counter-clockwise or clockwise, respectively): Defined as the steering wheel angle (clocking) deviation from "level" while maintaining a straight heading on a typical straight road. 3. Irregular or Premature tire wear: Slight to very slight "feathering" or "edge" wear on the shoulders of tires is NOT considered unusual and should even out with a tire rotation; if the customer is concerned about a "feathering" condition of the tires, the customer could be advised to rotate the tires earlier than the next scheduled mileage/maintenance interval (but no later than the next interval). Be sure to understand the customer's driving habits as this will also heavily influence the tire wear performance; tire wear from aggressive or abusive driving habits is NOT a warrantable condition. Important Slight or mild feathering, cupping, edge or heel/toe wear of tire tread shoulders is "normal" and can show up very early in a tire/vehicle service mileage; in fact, some new tires can show evidence of feathering from the factory. These issues do NOT affect the overall performance and tread life of the tire. Dealer personnel should always check the customer's maintenance records to ensure that tire inflation pressure is being maintained to placard and that the tires are being rotated (modified-X pattern) at the proper mileage intervals. Wheel alignments are NOT to be performed for the types of "Normal" Tire Feathering shown in Figures 1-4 below. Page 5888 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Page 5221 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 397 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 1088 Fluid - A/T: Technical Service Bulletins A/T - New Trans Fluid, Dexron IIE Number: 92-26-7A Section: 7A Date: OCT. 1991 Corporate Bulletin No.: 177125 ASE No.: A2 Subject: DEXRON-IIE AUTOMATIC TRANSMISSION/TRANSAXLE FLUID Model and Year: 1976-92 ALL TRUCKS WITH AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: SUBJECT: All Automatic Transmissions DEXRON-IIE Automatic Transmission/Transaxle Fluid TRANSMISSION MODELS: VEHICLE APPLICATIONS: All All HYDRA-MATIC Automatic Transmissions/Transaxles Bulletin Covers: General Motors Corporation has developed a new service fill automatic transmission/transaxle fluid which is designated DEXRON-IIE. This fluid is the preferred fluid for all HYDRA-MATIC automatic transmission/transaxles and will eventually replace DEXRON II. DEXRON-IIE is acceptable for use wherever DEXRON II was previously specified. DEXRON II is acceptable for use when DEXRON-IIE is not available. DEXRON-IIE can be used in both electronically and hydraulically controlled transmissions/transaxles. DEXRON-IIE Advantages: ^ Has better anti-foaming characteristics. ^ Improved low temperature flow characteristics (low temperature viscosity) and improved high temperature oxidation stability. ^ DEXRON-IIE and DEXRON II can be mixed in any ratio. No draining or flushing of system is required. ^ DEXRON-IIE is back serviceable to 1949 for all General Motors automatic transmission/transaxles. ^ No change in transmission/transaxle calibration or reduction in transmission/transaxle durability will occur as a result of using DEXRON-IIE. Service Parts Information: PART NUMBER DESCRIPTION 12345881 1 quart container 12345882 1 gallon container 12345883 55 gallon drum Parts are currently available from GMSPO. Page 5111 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 8319 Vanity Mirrors And Map lights Page 591 Coolant Temperature Sensor/Switch (For Computer): Description and Operation ECT Circuit (Typical) Engine Coolant Temperature Sensor PURPOSE Engine Coolant Temperature (ECT) Sensor is used to control: Exhaust Gas Recirculation (EGR) - Fuel delivery - Idle Air Control (IAC) - Ignition Control (IC) - Torque Converter Clutch (TCC) OPERATION The ECT sensor is a thermistor that is located in the engine coolant flow. Low coolant temperature sensor produces a high resistance (100,000 ohms at -40°C/-40°F). High coolant temperature, produces a low resistance (70 ohms at 130°C/266°F). The control module sends a 5.0 volt signal to the ECT through a resistor in the control module and measures the voltage. The voltage will be high when the engine is cold and low when the engine is hot. Engine coolant temperature affects most systems controlled by the control module. The control module uses information from the ECT to calculate spark advance as follows: Cold engine results in more spark advance. - Hot engine results in less spark advance. Locations LH I/P Harness Wiring Page 6900 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 5394 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 2948 Electronic Spark Control (ESC) Circuit Circuit Description: The Code 43 circuit consists of two knock sensors with one wire that goes directly to the ECM. There are two Code 43 checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 4.4 volts. If voltage is either too high or too low for 2 or more seconds, Code 43 will set. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3800 rpm, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, Code 43 will set. Diagnostic Aids: The ECM applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the ECM, is able to read this signal as knock and incrementally retard spark. If the ESC system checks OK, but detonation is the complaint, See: Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Electrical Specifications Throttle Position Sensor: Electrical Specifications The throttle position sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Page 5920 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Page 517 Page 428 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 6034 Wheel Bearing: Adjustments Four Wheel Drive - 4WD FRONT WHEEL BEARINGS ADJUSTMENT 4 X 2 MODELS 1. Raise and support front of vehicle. 2. Remove hub dust cover, then the cotter pin. 3. While rotating wheel assembly in forward direction, torque spindle nut to specification to fully seat the bearings. 4. Loosen nut to the ``just loose'' position, then tighten the spindle nut finger tight. 5. If either spindle hole does not line up with a spindle nut slot, back off spindle nut not more than 1/2 nut flat. 6. Install new cotter pin, then measure hub endplay. Endplay should be .001-.005 inches when properly adjusted. 7. Install hub dust cover and lower vehicle. 4 X 4 MODELS These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Page 3984 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 8665 Tools Front Door Trim Panel Page 3380 Fuel Pump And Sender Assembly (Typical) Page 1602 Camshaft: Specifications Camshaft Lift Specs Camshaft lift should measure .357 inch at intake valves and .390 inch at exhaust valves. Page 3892 A/C - Levers Loose or Binding Control Assembly: Customer Interest A/C - Levers Loose or Binding Number: 92-277-1A Section: 1A Date: AUGUST 1992 Corporate Bulletin No.: 261106 ASE No.: A7 Subject: TEMPERATURE CONTROL OR HVAC LEVERS LOOSE OR BINDING Model and Year: 1986-92 S/T TRUCKS Page 1672 Intermediate Shaft: Service and Repair BALANCE SHAFT REPLACEMENT Remove Tools Required: J 23523-E Torsional Damper Puller and Installer. J 26941 Needle Bearing Remover J 38834 Balance Shaft Bearing Service Kit. 1. Negative battery cable. 2. Air cleaner and air intake duct. - Drain the cooling system. 3. Discharge A/C system. 4. Upper radiator shroud. 5. Oil cooler lines at the radiator. 6. Transmission cooler lines at the radiator. 7. Upper radiator hose. 8. Heater hose and overflow hose from radiator. 9. Lower radiator hose. 10. Radiator. 11. A/C condenser. 12. Fan assembly. 13. Multiple ribbed belt. 14. Pencil brace at coolant pump. 15. Coolant pump. 16. Torsional damper. Use J23523-E. 17. Flywheel inspection cover. - Drain engine oil. - Loosen the oil pan. Remove the two nuts and the first two bolts on either side at the front of the oil pan, all other oil pan fasteners must be very loose. 18. Front cover bolts and front cover. Important - Use care when removing the front cover from the front of the oil pan gasket. 19. Crankshaft front oil seal from the front cover. 20. Timing chain bolts. Page 8316 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Instrument Panel - Upper Surface Cleaning Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel - Upper Surface Cleaning Number: 91-285-0A Section: 0A Date: APRIL 1991 Corporate Bulletin No.: 101003 Subject: CLEANING OF UPPER INSTRUMENT PANEL SURFACES Model and Year: ALL PASSENGER CARS AND TRUCKS ALL YEARS Comments on reflection into the windshield of the upper instrument panel may be received. The condition of instrument panel reflection into the windshield in direct sunlight may be aggravated by dealers and owners applying a wax or silicone base material to the pad surface. The higher gloss of such application results in a "veiling reflection" in the windshield. Advise customers and new car make ready area that materials containing wax or silicone should not be used to clean the instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap, or an equivalent should be used whenever the instrument panel pad needs cleaning. Steering - Column Popping Noise Steering Column Bearing: Customer Interest Steering - Column Popping Noise Group Ref.: Steering/Suspension Bulletin No.: 333210A Date: December, 1993 SUBJECT: STEERING COLUMN POPPING NOISE (REPLACE UPPER BEARING INNER RACE SEAT) MODELS: 1992-93 PASSENGER CARS EXCEPT CHEVROLET CAVALIER, GEO AND PONTIAC LEMANS 1992-93 LIGHT DUTY TRUCKS EXCEPT GEO TRACKER This bulletin is being re-published to add the labor time for Labor Operation Number E7310. Vehicles affected have TILT steering columns (round style) with the exception of the "W" series (square style). CONDITION: Some owners of vehicles with integral TILT steering columns may hear a pop noise when turning. The noise occurs specifically when the driver is making normal steering turns in either direction and generally when the steering wheel is returning to center. CAUSE: The upper bearing inner race seat under certain conditions may cause a pop noise. The part may have a burr on the inside skirt. CORRECTION: To verify that the upper bearing inner race seat is the cause of the pop noise in the steering column, use the following method: 1. Engage the park brake and start the engine. 2. Point the wheels of the vehicle straight ahead. 3. While listening for a pop noise, rotate the steering wheel in either direction to the wheel stop. Slowly return the wheel back to center. If the noise is not heard, drive the vehicle at a slow speed listening for the noise to occur. Important: When the steering column is warm, the pop noise will be more audible. 4. If a pop noise is heard, replace the upper bearing inner race seat with P/N 7815184. Return the steering wheel back to center with the wheels of the vehicle pointed straight ahead. Turn the ignition lock cylinder to "LOCK" position and then begin the repair. Refer to Section 3F5A/3F5B in the Service Manual to replace the upper bearing inner race seat. Parts are currently available from GMSPO. Labor Operation Number: E7310 Labor Time: 0.6 hrs. For GMC Truck ONLY, use: T7681 Labor Time: 0.4 hrs. (With SIR add .2 hrs.) Page 6848 Tool Required: J-21104 Trim Pad Remover. REMOVE OR DISCONNECT 1. Door pillar molding. 2. Window regulator handle. 3. Armrest. 4. Power window switch, if used. 5. Trim panel. Pry the fasteners from their seats using J-21104. INSTALL OR CONNECT 1. Trim panel to the door. 2. Armrest. 3. Window regulator handle. 4. Power window switch, if used. 5. Door pillar molding. Page 7716 Symbol Identification Specifications Intake Air Temperature Sensor: Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Specifications Heater Hose: Specifications Heater Hose Clamp Screw .................................................................................................................. ................................................... 1.7 Nm (15 in. lb.). Turbo Hydra-Matic 4L60 (700-R4) Throttle Valve Cable/Linkage: Adjustments Turbo Hydra-Matic 4L60 (700-R4) Fig. 4 Typical TV Cable Adjuster Fig. 5 TV Cable Adjustment. Models W/V6 And V8 Gasoline Engines Except Astro, Safari & S/T-10/15 Page 5978 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Page 7179 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 5580 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Page 1560 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Turbo Hydra-Matic 3L30 (180C) Fluid - A/T: Testing and Inspection Turbo Hydra-Matic 3L30 (180C) Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface and engine idling in Park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, if fluid level is too low, complete loss of drive may occur especially when cold, which can cause transmission failure. The oil should be drained, the oil pan removed, the screen cleaned and fresh fluid added every 30,000 miles for trucks under 8600 lbs. GVWR or every 24,000 miles for vehicles over 8600 GVWR. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or as a tow vehicle this maintenance should be performed every 15,000 miles for trucks under 8600 GVWR, or every 12,000 miles for trucks over 8600 GVWR. Page 5330 Disclaimer Page 2953 Manifold Pressure/Vacuum Sensor: Locations CMFI Intake Manifold Sensors/Valves Page 6145 Installing Clutch Plate & Hub Assembly 4. Remove the J 33013-B remover-installer center screw and reverse the body direction on the center screw as shown in the illustration. 5. Install the clutch plate and hub installer J 33013-B with bearing as shown in the illustration. The body of the J 33013-B installer should be backed off sufficiently to allow the center screw to be threaded onto the end of the compressor shaft. 6. Hold the center screw with a wrench. Tighten the hex portion of the installer J 33013-B body to press the hub onto the shaft. Tighten -the body several turns, remove the installer-and check to see that the shaft key is-still in place in the keyway before installing the clutch plate and hub assembly to its final position. The air gap between frictional surfaces of the clutch plate and clutch rotor should be 0.50-0.076 mm (0.20-0.030"). - If the center screw is threaded fully onto the end of the compressor shaft, or if the body of the installer is held and the center screw is rotated, the key will assume the position and will break the clutch hub. 7. Remove installer J 33013-B, check for proper positioning of the shaft key (even or slightly above the clutch hub). Install the shaft nut. Hold the clutch plate and hub assembly with clutch hub holding tool J 33027-A and using shaft nut socket J 33022, tighten the nut against the crankshaft shoulder to 16.5 N.m (12 lbs.ft.) torque, using a 17.5 N.m (12.5 lbs.ft.) torque wrench. 8. Spin the pulley rotor by hand to see that the rotor is not rubbing the clutch drive plate. Clutch Rotor and/or Bearing Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. Page 5972 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: All Technical Service Bulletins Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Page 2589 - Cruise control - ANTILOCK brake system. CONSTRUCTION The VSS is made up of: Permanent Magnet (PM) generator (coil), which is mounted on the transmission. - Rotor (tooth), which is mounted on the output shaft in the transmission. - VSS Buffer, which is mounted to the control module bracket. OPERATION The VSS is a Permanent Magnet (PM) generator that produces a pulsing Alternating Current (AC) voltage as each rotor tooth nears the coil. As the vehicle speed increases, the number of AC voltage pulses increase. The VSS buffer processes inputs from the VSS and outputs signal to the speedometer control module and cruise module. The VSS buffer takes the voltage pulses from the VSS and uses them to open and close four solid state output switches to ground at a rate proportional to vehicle speed. The VSS buffer is matched to the vehicle based on final drive ratio and tire size. Page 7306 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 7091 Sherwin-Williams, Acme/Rogers, and Martin-Senour are available in acrylic lacquer, acrylic enamel, or acrylic urethane. S-W use: prefix 34, J4 or L10/L11 for acrylic lac- quer, prefix 35, J5 or F10/F11 for acrylic enamel, prefix UB for acrylic urethane in a basecoat/clearcoat system, prefix US for acrylic urethane in a sin- gle stage system. ACME use: prefix 84 for acrylic lacquer, prefix 85 for acrylic enamel, prefix PB for acrylic urethane in a basecoat/clearcoat system, prefix PS for acrylic urethane in a single stage system. Rogers Use: prefix 94 for acrylic lacquer, prefix 95 for acrylic enamel, prefix AU for acrylic urethane in a basecoat/clearcoat system, prefix AS for acrylic urethane in a single stage system. Martin-Senour: Jobber will interchange number shown when acrylic lacquer is needed, use prefix 98 for acrylic urethane as an inter-mix basecoat/clearcoat, use prefix 88 for acrylic urethane as a factory packaged basecoat/clearcoat, use prefix 97 for acrylic urethane as an inter-mix single stage system, use prefix 87 for acrylic urethane as a factory packaged single stage system. 1992 TRUCK EXTERIOR COLORS Paint BASF Glasurit Color Fisher Martin- Sherwin-Williams PPG Rinshed 54-21 Code Color Name W-Code DuPont Senour Acme-Rogers DDL-DAR Mason Line 10 Gray White 9225 B8796 36783 36783 4015* 18121 GM-9225 12 Yellow White 5111 817 82-1208 F8W-2030 2185 1347 GM-5438 1492 15 Astral Silver 8914 C8501 82-5915 34856 3796* 15251 GM-8914 16 Warm Gray Metallic B/C 9659 B9125 44149 44149 4314 21017 GM-9659 17 Lt. Slate Metallic 7468 B8235 82-5579 32377 3453 12866 GM-7023 19 Lamp Black 5118 99 8800 F10B-1738 9000/9300 Standard GM-1240 80-4080 Package 22 Bahama Blue Met. B/C 9656 B9126 44150 44150 4307 21018 GM-9656 23 Ocean Blue 7154 B8041 82-5258 30527 3250 11500 GM-5481 24 Med. Bright Blue Metallic 9222 B8894 38144 38144 4110 18120 GM-9222 25 Bright Teal 9830 B9224 45877 45877 4469 22263 GM-9830 26 Pastel Blue 9662 B9128 44151 44151 4308 21019 GM-9662 27 Lt. French Blue Metallic 9264 B8944 39337 39337 4146 19031 GM-9264 29 Dark Blue 7349 B8139 82-5448 31514 3362 12283 GM-5039 30 Gray Blue Metallic 9086 B9017 42478 42478 4238 20050 GM-9086 34 Lt. Teal Metallic 9793 B9221 45878 45878 4455 21040 GM-9793 36 Med. Dk. Teal Metallic 9828 B9222 45879 45879 4347 22073 GM-9828 37 Light Mesa Brown 9219 B8897 38147 38147 4111 18118 GM-9219 41 Black B/C 8555 99 82-5760 33756 9700 13572 54-1240 43 Seafoam Green 9663 B9129 44152 44152 4309 21020 GM-9663 46 Dark Green 7156 B8046 82-5263 30530 3255 11505 GM-5482 47 Dark Blue Metallic 9095 B9019 42479 42479 4251 20052 GM-9095 48 Dark Red 9096 B9020 42480 42480 4239 20053 GM-9096 50 Blue White 8624 B8550 82-5918 34851 3800 15255 GM-8624 51 Sedona Tan 8528 B8542 90-5857 34392 4310 15022 GM-8528 54 Dk. Green Blue Metallic 9831 B9225 45913 45913 45DO 22267 GM-9831 57 Beige Metallic 5400 B9213 45881 45881 4346 22271 GM-5400 61 Tan 8265 B8462 82-5799 34070 3686 14241 GM-1074 71 Red Orange 7753 B8250 82-5586 32384 3463 12884 GM-3046 72 Standard Red 7475 B8241 82-5539 32097 3464 12885 GM-3047 74 Victory Red 9260 B8946 39339 39339 4154 19030 GM-9260 75 Red Metallic B/C 8919 C8506 82-5945 34855 3804* 15259 GM-89191 76 Dk. Garnet Red Met. B/C 9154 B8742 36454 36454 4002* 21023 GM-9154 78 Dark Yellow Red Metallic 8800 B8632 90-6069 35366 3915 16117 GM-3091 90 Gray Metallic 8798 B8629 82-6011 35367 3916 16118 GM-8798 Page 5103 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 4289 Pinion Bearing: Service and Repair Dana/Spicer 9 3/4 Inch Ring Gear Fig. 5 Pinion Setting Chart If original ring gear and pinion assembly are to be reused, measure original shim pack and build a new shim pack to the same dimension. If baffle is in the axle assembly, it is considered part of the shim pack. Ring gears and pinions are supplied in matched sets only. If a new gear is being used, verify numbers on pinion and ring gear before proceeding with assembly. On the button end of the pinion there is a +, - , or 0 number which indicates the best running position for each particular gear set. This position is controlled by shims installed behind the inner bearing cup. If baffles or oil slingers are used, they are considered part of the adjusting shim pack. If a new gear set is being installed, note the plus or minus mark on both old and new pinions and adjust thickness of shim pack to compensate for the difference between these two numbers. Refer to chart, Fig. 5, when determining shim size. 1. Install inner shim pack and, on 9-3/4 inch ring gear axle, the oil slinger in inner or rear cup bore, then drive cup into position using suitable tool. 2. Add or remove an equal amount to the outer shim pack as was added to the inner shim pack. 3. Drive outer cup into carrier bore, then press rear pinion bearing onto pinion shaft. 4. Install drive pinion and bearing into differential carrier. 5. Install shims and outer or front pinion bearing. 6. Install companion flange, then the washer and nut on pinion shaft. 7. Measure rotating torque of pinion shaft. Rotating torque should measure 10-20 inch lbs. with original bearings installed, or 20-40 inch lbs. with new bearings installed, discounting torque required to start turning shaft. 8. If rotating torque is not within specifications, adjust shim pack as necessary. Increase outer shim pack to reduce torque, or decrease shim pack to increase torque. 9. Remove nut, washer and companion flange from pinion shaft. 10. Install oil slinger, gasket (if equipped) and oil seal onto pinion shaft. 11. Install companion flange, washer and nut and torque as described is step 7. Disassembly Fig. 9 Drive Pinion Removal Description and Operation Fuel Pump Relay: Description and Operation OPERATION When the ignition key is first turned to the "ON" position, the control module will energize the fuel pump relay as long as the engine is cranking or running, and the control module is receiving distributor reference pulses. If there are no reference pulses, the control module will shut "OFF" the fuel pump relay within two seconds. An inoperative fuel pump relay can result in extended crank times, particularily if the engine is cold. The oil pressure switch will turn "ON" the fuel pump, as soon as oil pressure reaches about 28 kPa (4 psi). Diagram Information and Instructions Cruise Control Switch: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 6806 Page 47 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 3550 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Page 7617 Symbol Identification Speedometer - Registers When Vehicle is Stationary Speedometer Head: Customer Interest Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. Diagram Information and Instructions Antilock Brake Module: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 4932 Neutral Safety Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 8144 Brake Light Switch: Adjustments Fig. 2 Stop Light Switch Installation 1. Disconnect battery ground cable. 2. Disconnect wiring connector from brake light switch located on brake pedal bracket. 3. Pull switch from mounting bracket. 4. Depress brake pedal, then push new switch into clip until shoulder bottoms out, Fig. 2. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed .53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Page 2870 The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/OXYGEN SENSOR TESTING. Page 2156 Water Pump: Service and Repair Fig. 19 Water Pump Bolt Location 1. Drain cooling system. 2. Remove serpentine drive belt, then the upper fan shroud. 3. Remove fan, fan clutch assembly and water pump pulley, Fig. 19. 4. Remove hoses from pump. 5. Remove water pump attaching bolts, then pump. 6. Reverse procedure to install. Torque bolts to specification. Specifications Thermostat: Specifications Thermostat Opening Temperature 195 F Adjustments Idle Speed Control Motor: Adjustments Base Idle Speed is not adjustable on this engine and is controlled by the control module. Refer to FUEL SUPPLY AND AIR INDUCTION/ADJUSTMENT PROCEDURES for adjusting Controlled Idle Speed. Page 6059 Air Door Actuator / Motor: Component Tests and General Diagnostics Vacuum Schematic Initial Inspection and Diagnostic Overview Engine Control Module: Initial Inspection and Diagnostic Overview Diagnostic Circuit Check Page 4949 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 6379 Page 6374 Use the octagon sockets on the straight fittings (J 39037 high side, and J 41256 low side). Torque the new fitting until it seats. The fitting should seat fully BEFORE reaching 11 N.m (8 lb ft). If 11 N.m (8 lb ft) of torque is reached and the fitting has not seated, it is probable that the threads have been damaged. In this case, remove the fitting and use the thread restorer listed above. Reinstall the fitting, adding one drop of a thread locking compound such as Loctite(R) 242. The fittings (except the two-piece) have a thread locking compound applied to the threads. This compound will set up enough to restrict removal of the fitting in about 15 minutes. The fittings can now be used to evacuate the system (see Step 5). An additional type of conversion port fitting has been developed. This fitting is called a saddle clamp valve (see Figure 5). It can be clamped directly on a metal refrigerant line, and will be used if the existing fitting is damaged or is inaccessible. A drop of a thread locking compound, such as Loctite(R) 242, should be used on each bolt to prevent the threads from loosening. The R134a saddle clamp valve part numbers are: If an existing R-12 service port is not used, it must be rendered inoperative. Place several drops of a thread locking compound, such as Loctite(R) 243, in the valve core, and onto the cap threads. Secure the cap and let it set for 15 minutes. 4. Install Any Additional Parts Needed See "Platform Details" after Step 6. If a vehicle is listed as a "Basic Retrofit", no additional parts are required (except for compressors, see the Compressor Replacement Chart at the beginning of Platform Details). If no parts are required, PROCEED TO STEP 5. Compressors Compressors do not need to be replaced as part of a normal retrofit, unless indicated in the Compressor Replacement Chart. An R-12 compressor that is operating properly can, in most cases, be left in the vehicle when it is retrofitted to R134a. However, if a compressor failure is the reason the vehicle is in for service, and the vehicle will be retrofitted, OR if a vehicle has already been retrofitted with R-134a and the compressor fails at some time in the future, new compressors for use with R-134a are available. See the GMSPO Parts Catalog for specific part numbers. DO NOT use a replacement R-12 compressor for any vehicle retrofitted to R-134a (unless it is the new "oil-less" design). See "Compressor Availability" at the end of the Compressor Replacement Chart. Accumulator /Dryer If the vehicle is more than 5 years old, the Accumulator/Dryer (A/D) should be replaced to ensure that moisture is removed from the system. See the instructions for proper A/D identification in General Information. High Pressure Cut-Off Switch (HPCOS) Most trucks, and some 1984-93 B and D cars, require that a HPCOS be added to protect the refrigerant system during long idles at high temperature. The HPCOS kit (P/N 15981985) contains the switch, wire harness, heat sealing splice connectors, switch "0" ring, and installation instructions. A saddle clamp adapter (P/N 15985307), or a special dual fitting, is mounted to the high pressure line, and provides the port to mount the switch. A drop of a Page 6358 Housing Assembly HVAC: Description and Operation SYSTEM DESCRIPTION Control of air through the system is regulated by vacuum. At various positions of the levers on the control head, mode doors mix and direct cooled, heated, and outside air through the air ducts. VACUUM LINES Vacuum lines are molded to a connector which is attached to a vacuum control switch on the control assembly. In case of leakage or hose collapse, it will not be necessary to replace the entire harness assembly. Replacement can be made by cutting the hose and inserting a plastic connector. If the entire hose must be replaced, cut all hoses off at the connector and then attach hoses directly to the control assembly vacuum switch. VACUUM TANK During heavy acceleration, the vacuum supply from the intake manifold drops. Under load conditions a check valve in the vacuum tank maintains vacuum so that it will be available for future use. The vacuum tank is located in the engine compartment. DUCT AND OUTLETS A system of ducts and outlets directs air to the passenger compartment. In cases of poor air output, defroster, heater, AC, and vent ducts should be checked for obstructions such as leaves, dirt, or objects which may have fallen into the ducts from the passenger compartment. Page 6250 Removing Shaft Seal 6. Fully engage the knurled tangs of seal remover-installer J 23128-A into the recessed portion of the seal by turning the handle clockwise. Remove the seal from the compressor with a rotary-pulling motion. Discard the seal. The handle should be hand-tightened securely. Do not use a wrench or pliers. Removing Or Installing Shaft Seal O-Ring 7. Remove and discard the seal O-ring from the compressor neck using O-ring remover J 9553-1. 8. Thoroughly clean seal O-ring groove in front head. 9. Recheck the shaft and inside of the compressor neck for dirt or foreign material and be sure these areas are perfectly clean before installing new parts. Inspect Page 403 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 5554 Alignment: Service and Repair Front Toe Adjustment Fig. 2 Tie Rod & Clamp Sleeve Positioning - To adjust, loosen clamp bolts at each end of steering tie rod adjustable sleeves. - With steering wheel in straight ahead position, turn tie rod adjusting sleeves to obtain proper adjustment. - After adjusting, check that number of threads showing on each end of sleeve are equal and that the tie rod end housings are at the right angles to steering arm. - Position tie rod clamps and sleeves, Fig. 2, and torque nuts to specification. Testing and Inspection Fuel Pump Control Unit: Testing and Inspection PROCEDURE: - Disconnect fuel module - With test light and ignition "ON", probe connector terminal "C" to ground. Circuit is OK if light is "ON". There is an open if the light is "OFF". - Probe connector terminals "C" to "D" with test light. Circuit is OK if light is "ON". There is an open in the ground circuit if light is "OFF". - Ignition "OFF", probe connector terminals "A" to "D" with test light. Ignition "ON", test light should illuminate for two seconds. There is an open in the circuit if the light is "OFF". - Replace fuel module if there is no twenty second fuel pump operation. Page 6769 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 2781 - Negative battery terminal. Page 4885 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 65 Fig. 8 Four Wheel Anti-lock Brake Wiring Circuit. 1992 4WD S/T Page 3894 Page 2365 Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Switch HP Engine LH Front Side Of Engine Front Of Intake Manifold Applicable to: 1992 4.3L/V6-262 HP Engine STD Engine Tires - Speed Rated Information Tires: All Technical Service Bulletins Tires - Speed Rated Information Group Ref.: 3 - Steering/Suspension Bulletin No.: 433502 Date: July, 1994 INFORMATION SUBJECT: SPEED RATED TIRES MODELS: 1995 AND PRIOR YEAR PASSENGER CARS AND LIGHT DUTY TRUCKS All original equipment passenger car and light duty truck tires used by General Motors have a speed rating symbol molded on their sidewall. This speed symbol, along with the tire's load index, make up the service description that follows the tire's size. The original equipment tire size, speed rating, and recommended inflation pressure are listed on the tire placard usually located on the driver's door edge. WHEN REPLACING TIRES, NEVER INSTALL A TIRE THAT IS A SMALLER SIZE OR LESSER SPEED RATING THAN THAT USED AS ORIGINAL EQUIPMENT. As in the past, it is recommended that replacement tires have a TPC (Tire Performance Criteria) number on the sidewall that is identical to that on the original tires. Common speed rating on tires used by General Motors are as follows: (see illustration) IMPORTANT: Most base all season tires and touring tires used by GM are S rated. Performance tires will usually have a higher speed rating. High performance tires are usually Z rated. Z rated tires carry the Z symbol within the tire size, rather than after the size in the service description. These speeds apply only at the tire's full pressure. An underinflated tire will not meet its speed rating capability. Page 7162 Rear Of Instrument Cluster. On Brake Pedal Support Page 4626 Brake Bleeding: Technical Service Bulletins Brake Pressure Modulator Valve - Bleed Procedure Number: 93-12-5 Section: 5 Date: SEPT. 1992 Corporate Bulletin No.: 263003R ASE No: A5 Subject: REVISED BRAKE PRESSURE MODULATOR VALVE (BPMV) BLEED PROCEDURE Model and Year: 1990-93 LIGHT DUTY TRUCKS WITH 4WAL SERVICE UPDATE The brake pressure modulator valve (BPMV) (formerly called the EHCU) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves (item A, figure 1) 1/4 to 1/2 turn before bleeding. Should the BPMV need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTE: The ignition switch must be in the "OFF" position or false diagnostic trouble codes could be set to memory. Tools Required: J 39177 Combination Valve Pressure Bleeding Tool (Three Required) TK 00000 Tech-1 Scan Tool TK 02650 RWAU4WAL Cartridge Kit IMPORTANT You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV (figure 1). 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV (figure 1). Engine - Cold Knock PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine - Cold Knock Number: 93-155A-6A Section: 6A Date: AUGUST 1993 Corporate Bulletin No.: 376105R ASE No.: A1, A8 Subject: COLD ENGINE KNOCK Model and Year: 1991-93 C/K, R/V, M/L, S/T, G TRUCKS WITH 4.3L, 5.7L AND 7.4L ENGINES THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 93-155-6A DATED MARCH 1993. THE CORRECTION SECTION HAS BEEN CHANGED COMPLETELY. COPIES OF 93-155-6A SHOULD BE DISCARDED. CONDITION: Some late model LB4 (VIN Z 4.3L V6), L05 (VIN K 5.7L V8), and L19 (VIN N 7.4L V8) truck engines have been reported to exhibit "cold knock" on start up. "Cold knock" usually occurs after the vehicle has been completely warmed, then parked for 8 or more hours in ambient temperatures of 35 degrees Fahrenheit or less. "Cold knock" can be separated into three distinct categories. A. Short Duration - Harsh deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. B. Valve Train - Light clatter, tick or click that may last up to 1 minute. C. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. CORRECTION - CATEGORY A: Short Duration Knock For 1992 LB4 4.3L VIN Z ONLY: Install PF52 oil filter. Install a revised PROM that reduces the engine spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROM will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROMs contain the previously released calibration update for torque converter clutch (TCC) lock-up (see Dealer Service Bulletin No. 92-75-7A) if the vehicle has an automatic transmission or neutral gear rattle if the vehicle has a manual transmission (see Dealer Service Bulletin No. 92-187A-7B). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Dealer Service Bulletin No. 92-285B-6E for more information on detonation. NOTE: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. SPO will be temporarily stocking four (4) PROMs for each light duty 1992 model year LB4 application. Base Detonation Fix Cold Knock Fix Combination Cold Knock and Detonation Fix The detonation fix (detonation fix only) PROMs will not be restocked by SPO when the current supply is exhausted. If a detonation fix PROM is required after the existing stock is exhausted, the combination cold knock and detonation PROM is to be used. Special Parts Assistance Center will have information available on each PROM. Select the PROM from the table. Old broadcast code (OLDB/C Code) information has been supplied to help determine if a detonation fix PROM has been installed previously. If the Old B/C Code can be found in the first table, a detonation fix has not been installed. If the broadcast code cannot be found in the tables, call the appropriate marketing division technical assistance group. PROMs are expected to be available from GMSPO August 30, 1993. Page 7709 Generator (GEN) Indicator Stays On When Engine Is Running Initial Inspection and Diagnostic Overview Engine Control Module: Initial Inspection and Diagnostic Overview Diagnostic Circuit Check Page 798 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 75 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 7268 Symbol Identification Locations EGR Valve Position Sensor: Locations Engine Wiring, LH Side Page 323 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 1155 ^ PAG oil used for future service if needed (mark PAG on box on label, Figure 6). ^ HR6 or R4 original compressor RETAINED - add 8 oz FAG oil to system ^ V5 original compressor RETAINED - add 9 oz V5 Retrofit oil to system. If V5 Retrofit oil is not available from GMSPO, REPLACE THE COMPRESSOR. c. Based on the above chart, add oil if needed. Use the new oil bottle and the extended tube kit, J 39500-71. Fill the bottle with at least 10 oz of oil. Attach the new bottle to the back of the ACR4, and open the oil fill valve. Allow the correct amount of oil to be drawn into the system. DO NOT allow the oil level to drop below the end of the pickup tube. This will prevent any air from being drawn into the system. If any oil was removed during the R-12 recovery evacuation steps, DO NOT add additional oil to replace it. d. Determine the correct amount of R-134a to use. Check the existing label of the vehicle for the R-12 charge amount. Use the formula {(R12 x .9) - .25 lb = R-134a} to determine the correct charge. This can also be stated as: Take 90% of the R12 charge, and subtract 1/4 lb. Follow the directions for the ACR4 cart to recharge the system. At the end of the process, "CPL" will be displayed. Close the high side valve. e. Start the vehicle, turn on the A/C system, and confirm that pressures are within normal operating ranges, as shown in the 1994 Service Manual. The 1994 Service Manuals can be used as a reference for diagnosis and specification of retrofitted systems. On some vehicles with automatic A/C controls or low charge diagnostics, the A/C compressor may not engage if any diagnostic codes were set during the retrofit. Check to see if any codes were set in either the HVAC or Engine Control systems. If they were, clear the codes following the directions in the Service Manual. Page 7527 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Fuel - Removal And Installation of CPI Fuel Line Clips Fuel Supply Line: All Technical Service Bulletins Fuel - Removal And Installation of CPI Fuel Line Clips BULLETIN NO: 93-6C-46 SECTION: 6C NUMBER: 3 CORPORATE REFERENCE NO: 266306 DATE: February, 1993 SUBJECT: INFORMATION ON INSTALLATION OF CPI FUEL LINE CLIPS MODELS: 1992-93 S/T AND M/L MODELS WITH 4.3L ENGINES (RPO L35) Improper installation of the fuel line clips which hold the fuel inlet and outlet tubes to the Central Port Fuel Injection (CPI) unit may result in an internal CPI fuel leak. A fuel leak may cause driveability problems or in extreme cases, hydrolock. Proper Removal and Installation of Fuel Line Clips: Removal Using needle nose pliers, firmly grasp the fuel fitting clip as shown in Figure 1 and pull the clip straight back from the fuel meter body. It may be necessary to lift the opposite side of the clip with a screwdriver. Discard the clip. Installation Always use a new clip and 0-rings (P/N 17112702). Using your fingers as shown in Figure 2, slide the clip over the fuel meter body making sure that the clip properly engages the slots in the fuel inlet and outlet tubes and that the clip is properly positioned over the fuel meter body on both the top and bottom sides. The clip will be properly positioned when the flanges on the fuel meter body protrude from the clip and the clip snaps in place. Important Do not install the clip from the bottom-up position, the clip will not properly retain the fuel lines. Install the clip from the top-down position as shown in Figure 2. Secondly, it is important to note that the fuel lines MUST be in the correct inlet/outlet openings (The lines will fit either opening). Lastly, the fuel lines MUST be correctly seated into the TB body to allow for proper installation of the clips. Page 8522 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 5526 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Page 2341 Remove or Disconnect 1. Coolant from the radiator. 2. Coolant reservoir hose. 3. Upper fan shroud. 4. Hoses. Page 5614 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine Off. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. Flushing Power Steering System 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return hose at pump inlet connector and plug connector port on pump. Position hose in large container. 3. While an assistant is filling reservoir with new power steering fluid, run engine at idle. turn steering wheel from stop to stop. Do not contact wheel stops or hold wheel in a corner as fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 4. Install all pipes and hoses. Fill system with new power steering fluid and bleed system as outlined under SYSTEM BLEEDING. 5. Operate engine for 15 minutes. 6. Remove pump return hose at pump inlet and plug connection on pump. While refilling reservoir, check draining fluid for contamination. If foreign material is still evident, replace all hoses, disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. Removal/Installation Fig. 22 Power Steering Pump Replacement. Except Turbo EXCEPT TURBO 1. Disconnect pressure and return hoses from power steering pump or steering gear housing, then secure ends in raised position to prevent oil drainage. Cap all open lines and fittings. 2. Remove power steering pump belt, then power steering pump attaching bolts. 3. Remove power steering pump assembly, Fig. 22. Fig. 23 Power Steering Pump Replacement. Turbo Page 5467 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 5669 Fig. 4 Adjuster plug removal 1. Install connectors using valve connector installer tool J-6217 or equivalent, Fig. 8. 2. Lubricate 24 balls with power steering fluid, then install alternately by color into rack piston, Fig. 9. Use ball retainer tool J-21552 or equivalent, Fig. 2, to hold balls inside. 3. Install balls in ball guide alternately by color, retain in guide with petroleum jelly. Fig. 10. 4. Connect ball guide, clamp and screws to rack piston. 5. Lubricate stub shaft, valve spool and seals with power steering fluid, then install into valve body. 6. Connect valve body, seal, worm shaft, races and roller bearing. 7. Install seal on adjuster plug, then needle bearing in adjuster plug using J-8524-1 and J-7079-2 or equivalent. Fig. 11. 8. Install seal, washer and retaining ring in adjuster plug. Retainer projections must not extend beyond washer when retainer ring is seated. Washer must rotate freely. 9. Install worm shaft and valve assembly into gear housing. 10. Install adjuster plug into gear housing using spanner wrench tool J-7624 or equivalent, Fig. 4. Page 758 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 4740 Brake Bleeding: Fundamentals and Basics BENCH BLEEDING Why A master-cylinder will develop little or no pressure if air is trapped in cylinder bore. Normal brake bleeding will not remove air trapped within the master-cylinder. How Clamp the master-cylinder securely in a vice. It is usually best to clamp the side of the vice onto the flat surface that is used to secure the master-cylinder to the brake booster. There are two basic methods for bleeding master-cylinder, one utilizes stroking the master-cylinder to expel air from the cylinder bore while the other utilizes a large syringe to backflush fluid from the outlet ports to the reservoir. Stroking Fill the master-cylinder with clean brake fluid. - The brake line fittings on the master-cylinder should be capped or plugged. NOTE: Special "bench bleeding" plastic fittings are available which allow for recirculating the brake fluid back into the reservoir. - Using a dull object, slowly stroke the master-cylinder piston, air and brake fluid will be expelled from the brake line fittings. Prior to releasing the piston plug or cap the outlet ports. - Repeat this procedure 8-10 times or until no air is emitted from the outlet ports. - When finished, cap the outlet ports and install the master-cylinder. Syringe Fill the syringe (one especially designed for brake bleeding) with clean brake fluid. - Insert the end of the syringe into one of the outlet ports on the master-cylinder. - Slowly compress the syringe and back flush the brake fluid through the master-cylinder. - A combination of air and brake fluid will be emitted from the inlet port in the fluid reservoir. - Repeat this procedure until only brake fluid is emitted into the reservoir. Cap the outlet ports and install the master-cylinder. Page 8345 Symbol Identification A/T - 2-3 Upshift or 3-2 Downshift Clunk Noise Output Shaft: Technical Service Bulletins A/T - 2-3 Upshift or 3-2 Downshift Clunk Noise INFORMATION Bulletin No.: 01-07-30-042F Date: February 05, 2010 Subject: Information on 2-3 Upshift or 3-2 Downshift Clunk Noise Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2005-2009 Saab 9-7X with 4L60-E, 4L65-E or 4L70-E Automatic Transmission (RPOs M30, M32, M70) Supercede: This bulletin is being revised to add the 2010 model year and 4L70E transmission. Please discard Corporate Bulletin Number 01-07-30-042E (Section 07 - Transmission/Transaxle). Important For 2005 model year fullsize utilities and pickups, refer to Corporate Bulletin 05-07-30-012. Some vehicles may exhibit a clunk noise that can be heard on a 2-3 upshift or a 3-2 downshift. During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is applied. The timing of this shift can cause a momentary torque reversal of the output shaft that results in a clunk noise. This same torque reversal can also occur on a 3-2 downshift when the 3-4 clutch is released and the 2-4 band applied. This condition may be worse on a 4-wheel drive vehicle due to the additional tolerances in the transfer case. This is a normal condition. No repairs should be attempted. Disclaimer Removal & Installation Distributor: Service and Repair Removal & Installation Distributor And Coil 4.3L Engine REMOVE/DISCONNECT NOTE Verify ignition switch is "OFF". 1. Wiring harness connectors at side of distributor. 2. Coil wire and sparkplug wires on either left or right side of distributor. 3. Distributor cap by two screws and set to side: - Bring engine to TDC on the compression stroke for #1 cylinder and align timing marks to 0~ . Scribe a mark on distributor housing in line with rotor. - Scribe a mark on engine in line with rotor. Note position of distributor housing in relation to engine. 4. Remove distributor bolt hold-down clamp, raise distributor noting rotor rotation, then remove distributor and gasket (if applicable). Do not rotate crankshaft with distributor removed from engine. INSTALL/CONNECT NOTE To ensure correct timing of distributor it must be installed with rotor correctly positioned as noted in Step 3 of the removal procedure. Line up rotor, mark on distributor housing, and mark on engine. If distributor shaft won't drop into engine, insert a screwdriver into cavity for distributor and turn oil pump driveshaft. 1. Distributor and gasket (if applicable). 2. Hold-down clamp and tighten bolt to 34 Nm (25 lb. ft.). 3. Distributor cap. 4. Wiring harness connectors at side of distributor. 5. Sparkplug wires and coil wires. 6. Check engine timing. Instrument Panel - Upper Surface Cleaning Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel - Upper Surface Cleaning Number: 91-285-0A Section: 0A Date: APRIL 1991 Corporate Bulletin No.: 101003 Subject: CLEANING OF UPPER INSTRUMENT PANEL SURFACES Model and Year: ALL PASSENGER CARS AND TRUCKS ALL YEARS Comments on reflection into the windshield of the upper instrument panel may be received. The condition of instrument panel reflection into the windshield in direct sunlight may be aggravated by dealers and owners applying a wax or silicone base material to the pad surface. The higher gloss of such application results in a "veiling reflection" in the windshield. Advise customers and new car make ready area that materials containing wax or silicone should not be used to clean the instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap, or an equivalent should be used whenever the instrument panel pad needs cleaning. Page 5654 Steering Gear: Component Tests and General Diagnostics 1. Disconnect pressure hose at pump. Use small container to catch any fluid which might leak. 2. Connect spare pressure hose to pump. 3. Connect pressure gauge J-5176-D to both hoses. Adapter J-38049-38 is required for 3.8L (VIN L) engine. 4. Open valve on gauge. 5. Start engine. Allow system to reach operating temperature, then check fluid level and add fluid if required. 6. when engine is at normal operating temperature, pressure reading on gauge (valve open) should be 80-125 psi. If pressure is more than 200 psi., check hoses for restrictions and poppet valve on steering gear for proper assembly. 7. Fully close valve three times. Do not leave valve fully closed for more than five seconds, as pump could be damaged.. Record pressure reading each time valve is closed. Three readings should be within 50 psi. of each other. a. If pressure readings are high enough, and are within 50 psi. of each other, pump is functioning properly. b. If pressure readings are high enough, but are not within 50 psi. of each other, flow control valve in pump is sticking. Remove and clean valve. Remove any burrs using crocus cloth or fine hone. If system contains some dirt, flush system. If system is exceptionally dirty, both pump and steering gear must be completely disassembled, cleaned and reassembled. 8. If pump checks to specifications, leave valve open and turn steering wheel to both stops. Record highest pressures and compare with highest pump pressure recorded. If pressure at both stops is not the same as maximum pressure, steering gear is leaking internally and must be disassembled and repaired. 9. Turn engine Off, then remove testing gauge and spare hose. Reconnect pressure hose, check fluid level or make needed repairs. Page 8276 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 1208 Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Page 40 Antilock Brake Module: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 939 Spark Plug Wire Routing 4.3W Page 7337 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 5049 Neutral Safety Switch: Service and Repair Manual Transmission 1. Disconnect battery ground cable. 2. Disconnect back-up lamp switch electrical connector. 3. Disconnect switch wiring from transmission bracket, four-wheel drive vehicles only. 4. Remove switch from transmission. 5. Reverse procedure to install. Page 8265 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 8401 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 7471 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Initial Inspection and Diagnostic Overview Vehicle Speed Sensor Signal Buffer: Initial Inspection and Diagnostic Overview 1. Check to see if BRAKE Fuse is blown. If fuse is blown, locate and repair source of overload. Replace fuse. Specifications Evaporator Core: Specifications Evaporator Tube-to-Condenser .............................................................................................................................................................. 17 Nm (13 ft. lbs.). Evaporator Tube-to-Evaporator ............................................................................................................................................................. 17 Nm (13 ft. lbs.). Evaporator-to-Accumulator .................................................................................................................. ................................................. 41 Nm (30 ft. lbs.). CALPAK PROM - Programmable Read Only Memory: Service and Repair CALPAK 1. Remove ECM from vehicle. 2. Remove ECM access cover. 3. Remove Calibration Pack (CALPAK) using removal tool shown. Grasp the CALPAK carrier on the narrow ends only. Gently rock the carrier from end to end while applying a firm upward force. 4. Inspect the reference end of the CALPAK carrier and carefully set aside. Do not remove the CALPAK from the carrier to confirm CALPAK correctness. The notch in the CALPAK is referenced to the small notch in the carrier. The small notch of the carrier must be aligned with the small notch in the socket. CAUTION: ANY TIME THE CALPAK IS INSTALLED BACKWARDS AND THE IGNITION SWITCH IS TURNED ON, THE CALPAK IS DESTROYED. 5. Install the CALPACK by pressing on the CALPAK carrier until it is firmly seated in the socket. Do not press on the CALPAK, only the carrier. 6. Install ECM access cover. 7. Install ECM and perform a DIAGNOSTIC CIRCUIT CHECK to confirm proper installation. Page 7356 Figure 7 Figure 8 Figure 9 Figure 10 Page 7588 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 279 Engine Sensor Locations. LH Front Of Engine Applicable to: Except 4.3L/V6-262 HP & 4.3L/V6-262 Turbo Engines Page 6693 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 3026 CMFI Intake Manifold Sensors/Valves Page 854 Verify Original Equipment Condition of the Vehicle - Verify that Original Equipment Tires and Wheels or Official GM Accessory Tires and Wheels are on the vehicle. - Verify that aftermarket suspension "Lift" or "Lowering" Kits or other suspension alterations have NOT been done to the vehicle. - Check for accidental damage to the vehicle; for example, severe pothole or curb impacts, collision damage that may have affected the wheel alignment of the vehicle; e.g., engine cradles, suspension control arms, axles, wheels, wheel covers, tires may show evidence of damage/impact. - Check to be sure vehicle has seen "Normal Use" rather than abuse; e.g., very aggressive driving may show up by looking at the tires and condition of the vehicle. - Check for other additional equipment items that may significantly affect vehicle mass such as large tool boxes, campers, snow plow packages (without the snowplow RPO), etc., especially in trucks and cutaway/incomplete vehicles. Significant additional mass can affect trim height and wheel alignment of the vehicle and may necessitate a customer pay wheel alignment when placed semi-permanently in the vehicle (Upfitter instructions are to realign the vehicle after placement of these types of items. (This typically applies to trucks and incomplete vehicles that can be upfit with equipment such as the above.) Customer Concerns, "Normal Operation" Conditions and "Mileage Policy" Possible Concerns The following are typical conditions that may require wheel alignment warranty service: 1. Lead/Pull: defined as "at a constant highway speed on a typical straight road, the amount of effort required at the steering wheel to maintain the vehicle's straight heading." Important Please evaluate for the condition with hands-on the steering wheel. Follow the "Vehicle Leads/Pulls" diagnostic tree located in SI to determine the cause of a lead/pull concern. Lead/Pull concerns can be due to road crown or road slope, tires, wheel alignment or even in rare circumstances a steering gear issue. Lead/pull concerns due to road crown are considered "Normal Operation" and are NOT a warrantable condition -- the customer should be advised that this is "Normal Operation." Important Some customers may comment on a "Lead/Pull" when they hold the steering wheel in a level condition. If so, this is more likely a "steering wheel angle" concern because the customer is "steering" the vehicle to obtain a "level" steering wheel. 2. Steering wheel angle to the left or right (counter-clockwise or clockwise, respectively): Defined as the steering wheel angle (clocking) deviation from "level" while maintaining a straight heading on a typical straight road. 3. Irregular or Premature tire wear: Slight to very slight "feathering" or "edge" wear on the shoulders of tires is NOT considered unusual and should even out with a tire rotation; if the customer is concerned about a "feathering" condition of the tires, the customer could be advised to rotate the tires earlier than the next scheduled mileage/maintenance interval (but no later than the next interval). Be sure to understand the customer's driving habits as this will also heavily influence the tire wear performance; tire wear from aggressive or abusive driving habits is NOT a warrantable condition. Important Slight or mild feathering, cupping, edge or heel/toe wear of tire tread shoulders is "normal" and can show up very early in a tire/vehicle service mileage; in fact, some new tires can show evidence of feathering from the factory. These issues do NOT affect the overall performance and tread life of the tire. Dealer personnel should always check the customer's maintenance records to ensure that tire inflation pressure is being maintained to placard and that the tires are being rotated (modified-X pattern) at the proper mileage intervals. Wheel alignments are NOT to be performed for the types of "Normal" Tire Feathering shown in Figures 1-4 below. Page 728 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Page 4938 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 7267 Symbol Identification Page 7190 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Spark Plug Gap, Torque and Type Spark Plug: Specifications Spark Plug Gap, Torque and Type Spark Plug Gap ................................................................................................................................... ...................................................... 1.14 mm (.045 ") Spark Plug Torque ............................................................................................................................... ...................................................... 15 N-m (11 lb.ft.) Spark Plug Type .................................................................................................................................. ............................................................. AC CR43TS NOTE Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Tires - Manufacturers' Assistance Tires: All Technical Service Bulletins Tires - Manufacturers' Assistance Group Ref.: Steering/ Suspension Bulletin No.: 323501 Date: December, 1993 INFORMATION SUBJECT: TIRE MANUFACTURERS' CONTACTS FOR ASSISTANCE MODELS: 1991-94 PASSENGER CARS AND TRUCKS General Tire has established a "Tire Fix" Department to assist you with anything from a tire adjustment to the location of the nearest General Tire dealer. "Tire Fix" representatives are available Monday through Friday from 8:00 A.M. to 6:00 P.M. Eastern Time at 1-800-847-3349. A General Tire Brochure is provided for review with all appropriate dealer personnel. A single contact point at General Tire can assist you with most aspects of their product to satisfy your customers' needs. Other tire manufacturers can be contacted for assistance at the Toll Free Numbers listed in illustration: Please retain this information for future reference. Page 5801 ^ Always inspect and adjust the pressure when the tires are cold. ^ Vehicles that have different pressures for the front and the rear need to be adjusted after tire rotation. Improper tire inflation may result in any or all of the following conditions: ^ Premature tire wear ^ Harsh ride ^ Excessive road noise ^ Poor handling ^ Reduced fuel economy ^ Low Tire Pressure Monitor (TPM) Light ON ^ Low Tire Pressure Message on the Drivers Information Center (DIC) Disclaimer Oil Pressure Gauge - Incorrect or Erratic Readings Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Incorrect or Erratic Readings Number: 93-57-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268304 ASE No.: A1, A8 Subject: INCORRECT OR ERRATIC OIL PRESSURE READINGS Model and Year: 1990-93 ALL LIGHT DUTY TRUCKS Owners of some 1990 through 1993 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. Service Procedure: Check for normal causes of high oil pressure gauge readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure below. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. connect the negative battery cable. Parts Information: Page 7676 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7626 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 6382 FOR ALL VEHICLES EXCEPT GEO, see the "Compressor Replacement Chart" at the end of this section. Compressor replacement requirements ARE NOT LISTED in the platform details (except for application details), except as noted below for Y car and P and Medium Duty truck. Compressor Replacement Chart Important: It is important to check the date code on the compressor. Any vehicle may have had a compressor replaced either during or after the warranty period. The date code will determine whether or not the compressor must be replaced. Compressor Availability A new compressor for use with R-134a systems will be shipped with the correct amount of PAG oil installed (see "IMPORTANT" below). Do not add any additional oil in Step 5 of the retrofit procedure if a compressor is to be replaced with a new R-134a compressor at the same time the initial retrofit is Page 3795 CORRECTION (Figure 2): To improve the 1-2 shift, install the service package listed in this bulletin. A 1-2 accumulator valve and 1-2 accumulator valve sleeve (which, normally, is not serviceable) is included in the package. SERVICE PARTS INFORMATION: Package Number Transmission Models 8687992 2AAM, 2ACM, 2BAM, 2BBM, 2BCM, 2BHM, 2BRM, 2BWM, 2CAM, 2CBM, 2CCM, 2CFM, 2CHM, 2CJM, 2FTM, 2FUM, 2HBM, 2HLM, 2KHM, 2KJM, 2KMM, 2LHM, 2MJM, 2SHM, 2TLM, 2TWM, 2WAM, 2WBM, 2WCM 8688900 2ADM, 2AKM, 2CPM, 2FZM, 2HDM, 2MDM, 2MSM, 2TAM, 2TBM, 2YAM, 2YCM WARRANTY INFORMATION: Labor Operation Number: T7601 (Valve Body, R&R;). Labor Time: C/K, G, L/M, S/T Trucks 1.8 hrs. Labor Time: Caprice 1.7 hrs. Camaro 1.4 hrs. Corvette 1.3 hrs. Corvette with folding top add 0.6 hrs. SERVICE MANUAL REFERENCE: Refer to the HYDRA-MATIC 4L60 Unit Repair Section of the appropriate service manual for repair information. Recall 93V008000: Cooling Fan Replacement Fan Blade: All Technical Service Bulletins Recall 93V008000: Cooling Fan Replacement THE ENGINE COOLING FAN BLADES BREAK AS A RESULT OF FATIGUE AND/OR VEHICLE INDUCED STRESS. IF THE BLADE BREAKAGE OCCURS WHILE THE HOOD IS OPEN, A PERSON WORKING UNDER THE HOOD OR IN THE VICINITY OF THE VEHICLE COULD BE STRUCK AND INJURED BY THE BLADE SEGMENT. INSTALL A NEWLY DESIGNED FAN ASSEMBLY. SYSTEM: ENGINE. VEHICLE DESCRIPTION: LIGHT TRUCKS WITH 2.5 L ENGINES WITHOUT AIR CONDITIONING. 1989 CHEVROLET TRUCK S10 1989 GMC S15 1990 CHEVROLET TRUCK S10 1990 GMC S15 1991 CHEVROLET TRUCK S10 1991 GMC S15 1992 CHEVROLET TRUCK S10 1992 GMC S15 Page 3750 PROM - Programmable Read Only Memory: Application and ID Footnotes 351 Thru 400 [351] USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [352] USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [353] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [354] Lack of throttle response on trucks equipped with governors; or hot restart driveaway sag, both governor and non-governor trucks. [355] Low speed driveability or detonation. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [356] Tip-in hesitation, sag, backfire, spark knock. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [357] Hesitation or sag during the first two minutes of cold operation while vehicle is under moderate to heavy throttle driveaway, or TCC chuggle. [358] Sustained detonation/knock. AUTOMATIC TRANSMISSIONS REQUIRE TORQUE CONVERTER CLUTCH (TCC) CALIBRATION. USE OF THIS PROM IN A NON-DETONATING ENGINE MAY RESULT IN DEGRADED DRIVEABILITY. [359] High emissions, exhaust odor, starting and driveability problems (G046). Requires Connector Bleed Assembly P/N 10105820 [360] Neutral gear rattle. MAY ALSO REQUIRE CLUTCH DRIVEN PLATE P/N 15961141, AND CLUTCH PILOT BEARING P/N 14061685. COMBINATION DETONATION AND NEUTRAL GEAR RATTLE PROM AVAILABLE. [361] Malfunction Indicator Lamp (check engine light) illuminates and may set a DTC 24 (VSS Circuit Fault) during a California State Emissions Test. [362] Higher than normal hydrocarbon emissions during the idle portion of the inspection and maintenance test. Also, may exhibit a slight detonation during a light throttle acceleration [363] TCC chuggle. MODEL 2DDM TRANS. - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS BEEN REPLACED WITH P/N 8650935 (BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (BCC: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED WITH P/N 8650935. [364] Cold start stall, cold tip in hesitation and/or a cold rough idle after extended idling. Additionally, in 40-50°F ambient temp., fogging on the inside of the front windshield which does not clear with the defroster on occurs. [365] Poor throttle response, stall, misfire, poor cold or hot start, extended crank of the starter with a hot engine, and/or vehicle will start and then stall when the engine is hot. MT vehicles may also experience decel. stall and poor accel. performance. [366] Poor throttle response, stalling, misfire, poor cold or hot starting, extended cranking of the starter with a hot engine, and/or vehicle will start and then stall when the engine is hot. USED WITH MANUAL TRANSMISSION ONLY. [367] MIL illuminates and/or store a DTC 32 (EGR error) with no noticeable driveability concern, usually occurring while climbing a grade. [368] MIL illuminates and/or store a DTC 32 (EGR error) with no noticeable driveability concern, usually occurring while climbing a grade, towing a trailer or driving into a strong head wind. [369] High emissions, exhaust odor, starting and driveability problems (G046). Requires Connector Bleed Assembly P/N 10105820 Page 8209 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 5483 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Removal Notes Brake Caliper: Fundamentals and Basics Removal Notes When Removing the Caliper, Remember... - Prior to removing the calipers, remove/siphon brake fluid from master-cylinder until the reservoir is only 1/3 full. - Brake fluid will remove paint and damage electrical connections. Use a drip pan and fender covers to protect the vehicle's finish and electrical system. - Always replace all brake linings on an axle. Never replace only one wheel. Unequal lining thickness between wheels on the same axle will result in a strong steering pull when the brakes are applied. - Work on one side at a time. If you forget how to reassemble the parts you can always use the other side as a model. - When forcing the piston back into the caliper, open the bleeder valve first. Corrosion and other deposits accumulate inside of the caliper. If the bleeder valve is not opened when the piston is forced back into the caliper, these deposits will be forced back through the brake lines and into the master-cylinder. When pushing the pistons back into the caliper with the bleeder screw open, a stream of brake fluid will be expelled from the bleeder screw for 2-3 feet. Use a drip pan and be careful not to "shoot" brake fluid onto the vehicle's finish. A cleaner method is to use a piece of clear plastic hose and a glass or plastic jar to catch the expelled fluid. - Upon removal, Do Not allow the calipers to hang by the flexible brake hoses. The brake hoses can be damaged easily by this practice. These hoses are double walled, damage to the interior pressure hose will not be visible. - Do not depress the brake pedal with either caliper removed from the rotor. The caliper pistons will be inadvertently expelled from the caliper. If this occurs rebuild or replace the caliper, do not attempt to insert the piston back into the caliper. Description and Operation Fuel Economy Warning System: Description and Operation This system actually monitors the engine vacuum just like the vacuum gauge, but registers only low vacuum readings. The light on the instrument panel warns the vehicle operator when engine manifold vacuum drops below the economical limit. Switch operation is similar to that of the oil pressure indicating light, except that the switch opens when vacuum pressure, rather than oil pressure, is applied. Page 5449 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Interior Door Handle Spring - Early Breakage Front Door Interior Handle: Customer Interest Interior Door Handle Spring - Early Breakage Group Ref.: Body Bulletin No.: 461601 Date: April, 1994 INFORMATION SUBJECT: INTERIOR DOOR HANDLE SPRING BREAKAGE MODELS: 1990-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1990-94 CHEVROLET AND GMC TRUCK S/T UTILITIES 1991-94 OLDSMOBILE BRAVADA Some vehicles may be found to have front side door interior door handles with broken springs. This condition tends to be associated with vehicles that experience high (frequent) usage of the door handle mechanism. To enhance spring durability, production vehicles are now receiving door handle assemblies with lithium grease added to the spring. The durability of replacement door handles obtained from GMSPO can be increased by adding lithium based lubricant to the door handle spring. The lubricant should be applied so that it works into and between the spring coils. This will allow the coils to move past each other freely, reducing spring breakage. SERVICE PARTS INFORMATION: P/N Description Qty Procure Locally Lithium Based As Needed Lubricant Description and Operation Overvoltage Protection Relay: Description and Operation PURPOSE Inform the control module that there is a basic generator over voltage problem. OPERATION PCM/ECM If voltage is greater than 19.5 volts for 2 seconds at PCM terminal "E16" (ECM is "C16"), the control module sets Diagnostic Trouble Code 53, the automatic transmission pressure control solenoid is turned "OFF", the automatic transmission shifts immediately to third gear, and TCC operation is inhibited. (the setting of additional DTC's may result.) VCM If voltage is greater than 17.1 volts at VCM terminal "GR2" sets Diagnostic Fault Code P1632. For 2 seconds after the fault is detected, the VCM will disengage its outputs. This may result in additional DTC's being set. Page 6089 Blower Motor Does Not Operate In Any Mode Blower Motor Does Not Operate In LO And/Or MED But Operates In HI Mirrors - Heated Mirrors, Defrosting Time Heated Element: Technical Service Bulletins Mirrors - Heated Mirrors, Defrosting Time INFORMATION Bulletin No.: 08-08-64-011A Date: February 25, 2010 Subject: Information on Heated Electrochromatic Outside Rearview Mirror Performance Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2009 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 08-08-64-011 (Section 08 - Body and Accessories). Defrosting Time/Performance Concern The electrochromatic (auto-dimming) outside rearview mirror used on the driver's side of many GM vehicles is slower to defrost than the passenger side outside rearview mirror. This is a normal condition. The glass on the driver's side electrochromatic mirror is twice as thick as the traditional glass on the passenger side mirror. The heating elements for the mirrors on both sides draw the same wattage, therefore the driver's side mirror will take approximately twice as long to defrost as the passenger mirror (approximately four minutes versus two minutes). Should a customer indicate that the driver's side heated mirror is not functioning correctly, verify it's function based upon this information prior to replacing the mirror. Disclaimer Oil Pressure Gauge - Incorrect or Erratic Readings Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Incorrect or Erratic Readings Number: 93-57-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268304 ASE No.: A1, A8 Subject: INCORRECT OR ERRATIC OIL PRESSURE READINGS Model and Year: 1990-93 ALL LIGHT DUTY TRUCKS Owners of some 1990 through 1993 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. Service Procedure: Check for normal causes of high oil pressure gauge readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure below. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. connect the negative battery cable. Parts Information: Page 1061 reservoir fluid level to full only after installing new brake pads and/or shoes. A full reservoir is indicated on translucent, snap cover reservoirs by a fluid level even with the top level of the view window imprinted into the side of the reservoir. On screw top models in black or translucent plastic, the full level is just below the bottom of the filler neck. Parts Information Part Number Description 12377967 Brake Fluid Parts are currently available from GMSPO. Disclaimer Vehicle - Engine Crankcase and Subsystems Flushing Info. Continuously Variable Transmission/Transaxle: All Technical Service Bulletins Vehicle - Engine Crankcase and Subsystems Flushing Info. INFORMATION Bulletin No.: 04-06-01-029E Date: April 29, 2010 Subject: Unnecessary Flushing Services, Additive Recommendations and Proper Utilization of GM Simplified Maintenance Schedule to Enhance Customer Service Experience Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and add information about the proper transmission flush procedure. Please discard Corporate Bulletin Number 04-06-01-029D (Section 06 - Engine/Propulsion System). An Overview of Proper Vehicle Service General Motors is aware that some companies are marketing tools and equipment to support a subsystem flushing procedures. These dedicated machines are in addition to many engine oil, cooling system, fuel system, A/C, transmission flush and steering system additives available to the consumer. GM Vehicles under normal usage do not require any additional procedures or additives beyond what is advised under the former Vehicle Maintenance Schedules or the current Simplified Maintenance Schedules. Do not confuse machines available from Kent-Moore/SPX that are designed to aid and accelerate the process of fluid changing with these flushing machines. Engine Crankcase Flushing General Motors Corporation does not endorse or recommend engine crankcase flushing for any of its gasoline engines. Analysis of some of the aftermarket materials used for crankcase flushing indicate incompatibility with GM engine components and the potential for damage to some engine seals and bearings. Damage to engine components resulting from crankcase flushing IS NOT COVERED under the terms of the New Vehicle Warranty. GM Authorized Service Information: Detailed, Descriptive, and Complete If a specific model vehicle or powertrain need is identified, GM will issue an Authorized Service Document containing a procedure and, if required, provide, make available, or require the specific use of a machine, tool or chemical to accomplish proper vehicle servicing. An example of this is fuel injector cleaning. Due to variation in fuel quality in different areas of the country, GM has recognized the need for fuel injector cleaning methods on some engines, though under normal circumstances, this service is not part of the maintenance requirements. GM has published several gasoline fuel injector cleaning bulletins that fully outline the methods to be used in conjunction with GM Part Numbered solutions to accomplish proper and safe cleaning of the fuel injectors with preventative maintenance suggestions to maintain optimum performance. You may refer to Corporate Bulletin Numbers 03-06-04-030 and 04-06-04-051 for additional information on this subject. Subsystem Flushing Flushing of A/C lines, radiators, transmission coolers, and power steering systems are recognized practices to be performed after catastrophic failures or extreme corrosion when encountered in radiators. For acceptable A/C flushing concerns, refer to Corporate Bulletin Number 01-01-38-006. This practice is NOT required or recommended for normal service operations. The use of external transmission fluid exchange or flush machines is NOT recommended for the automatic or manual transmission. Use of external machines to replace the fluid may affect the operation or durability of the transmission. Transmission fluid should only be replaced by draining and refilling following directions in SI. Refer to Automatic/Manual Transmission Fluid and Filter Replacement. Approved Transmission Flushing Tool (Transmission Cooler Only) The Automatic Transmission Oil Cooler Flush and Flow Test Tool is recommended for GM vehicles. Refer to Transmission Fluid Cooler Flushing and Flow Test in SI using the J 45096. Service Is Important to You and Your Customer General Motors takes great pride in offering our dealerships and customers high quality vehicles that require extremely low maintenance over the life of the vehicle. This low cost of ownership builds repeat sales and offers our customers measurable economy of operation against competing vehicles. Page 6156 3. Using a center punch with a 45° angle point, stake 1.1-1.4mm (0.045-0.055" deep) the bearing in three places 120° apart as shown in Figure 12, but do not stake too deeply to avoid distorting the outer race of the bearing. 4. Replace rotor and bearing assembly. On-Vehicle A. Position the Rotor and Bearing assembly on the front head. B. With Rotor & Bearing Installer J 26271-A (without driver handle) in position and Rotor and Bearing assembly aligned with the Front Head as shown in Figure 14, drive the assembly part way onto the head. C. Plug clutch coil connector onto Clutch Coil. D. Position the Clutch Coil so the three (3) locating tabs will align with the holes in the head and continue to drive the Rotor and Bearing assembly onto the front head. E. Install the retainer ring (Fig. 9). F. Reassemble the Clutch Plate and Hub with the shaft key onto the shaft with Installer J 9401-B until 0.5-7.6mm (0.20-0.030") air gap is obtained. G. Install shaft lock nut. Torque to 14 N-m (10 lb.ft.). On-Bench Page 5531 For vehicles repaired under warranty, use the table. Disclaimer Page 5177 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 2616 Rear Of Engine Page 4111 Valve Body: Technical Service Bulletins A/T - New Calibration Changed TV Limit Line-Up Number: 92-341-7A Section: 7A Date: JAN. 1993 Corporate Bulletin No.: 377102 ASE No.: A2 Subject: NEW CALIBRATION CHANGED TV LIMIT LINE-UP Model and Year: 1992 CAPRICE, CAMARO, CORVETTE AND 1992 C/K, S/T, G, M/L TRUCKS WITH 4L60 AUTOMATIC TRANSMISSION SERVICE UPDATE TRANSMISSION APPLICATIONS: 1992 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: 1992 Service Manual Update Transmission Unit Repair Update (General Information) VEHICLE APPLICATIONS: B, F, Y - Cars C/K, S/T - Trucks G, M/L - Vans BULLETIN COVERS: New Product Information for 1992 HYDRA-MATIC 4L60 transmissions. This information has been updated since publication of the 1992 Service Manual and should be noted accordingly. Be certain to familiarize yourself with these updates to properly repair the 1992 HYDRA-MATIC 4L60 transmission. DATE OF PRODUCTION CHANGE: On August 14, 1991 (Julian Date 226), the HYDRA-MATIC 4L60 transmissions were built with a new calibration that changed the TV limit line-up. The changes included a new TV limit valve (Ill. 332), a new TV limit valve spring (Ill. 331), and eliminates the TV limit plug (Ill. 351) Figure 112. Also included is an updated line pressure check chart and an updated 2nd apply piston and housing application chart. SERVICE MANUAL REFERENCE: Page 4095 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Page 6232 Compressor Clutch Hub: Service and Repair With HR100T/HR110T Compressor 4 POLE AND 6 POLE CLUTCH Remove or Disconnect 1. If compressor is on the vehicle, loosen compressor mounting brackets, disconnect the compressor drive belt and reposition the compressor for access, if necessary. If compressor has been removed from the vehicle, attach the compressor to Holding Fixture 3 25008-A and clamp the Holding Fixture in a vise (Fig. 5). - Compressor mounting holes are metric. Use proper metric bolts with holding fixture J 25008-A. 2. Keep the clutch hub from turning with the Clutch Hub Holding Tool J 33027-A, remove the shaft nut, using Thin Wall Socket J 9399 (Fig. 5). 3. Thread the Clutch Plate and Hub Assembly Remover J 33013-B, into the hub. Hold the body of the Remover with a wrench and turn the center screw into the Remover body to remove the Clutch Plate and Hub assembly (Fig. 6). 4. Remove the shaft key. Install or Connect Page 762 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 8058 Page 4617 Wheel Speed Sensor: Service and Repair Rear Wheel Speed Sensor Fig. 58 Rear Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Remove brake drum. 3. Remove primary brake shoe. 4. Disconnect sensor electrical connector. 5. Remove sensor wire from rear axle clip. 6. Remove speed sensor attaching bolts, Fig. 58, then remove sensor by pulling wire through hole in backing plate. 7. Reverse procedure to install. Torque speed sensor attaching bolts to 26 ft. lbs. Page 726 Knock Sensor: Testing and Inspection Electronic Spark Control (ESC) Circuit Check Page 1107 Parts Information Parts are currently available from GMSPO. Page 4266 Parts Information Parts are currently available from GMSPO. Page 2044 Intermediate Shaft: Service and Repair BALANCE SHAFT REPLACEMENT Remove Tools Required: J 23523-E Torsional Damper Puller and Installer. J 26941 Needle Bearing Remover J 38834 Balance Shaft Bearing Service Kit. 1. Negative battery cable. 2. Air cleaner and air intake duct. - Drain the cooling system. 3. Discharge A/C system. 4. Upper radiator shroud. 5. Oil cooler lines at the radiator. 6. Transmission cooler lines at the radiator. 7. Upper radiator hose. 8. Heater hose and overflow hose from radiator. 9. Lower radiator hose. 10. Radiator. 11. A/C condenser. 12. Fan assembly. 13. Multiple ribbed belt. 14. Pencil brace at coolant pump. 15. Coolant pump. 16. Torsional damper. Use J23523-E. 17. Flywheel inspection cover. - Drain engine oil. - Loosen the oil pan. Remove the two nuts and the first two bolts on either side at the front of the oil pan, all other oil pan fasteners must be very loose. 18. Front cover bolts and front cover. Important - Use care when removing the front cover from the front of the oil pan gasket. 19. Crankshaft front oil seal from the front cover. 20. Timing chain bolts. Page 2980 Throttle Position Sensor: Adjustments N/A: TPS is not adjustable on this engine. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Interior - Wind Noise At Side Marker Lamps Side Marker Lamp: All Technical Service Bulletins Interior - Wind Noise At Side Marker Lamps Number: 92-194-10 Section: 10 Date: May 1992 Corporate Bulletin No.: 261503 ASE No.: B1 Subject: WIND NOISE AT SIDE MARKER LAMPS Model and Year: 1990-92 S/T TRUCKS WITHOUT SPORT GRILLES Owners of some 1990-1992 S/T vehicles may comment on a wind whistle through the grille in the area of the side marker lamp(s). This condition may occur as air flows through the side marker lamp bracket(s). The whistling sound is intermittent and is affected by vehicle speed/direction and wind velocity/direction. To correct this condition, it is necessary to apply sealer along the entire leading edge of the side marker lamp(s). This eliminates the air flow through the mating surfaces of the lamp bracket(s) and the grille. SERVICE PROCEDURE: 1. Remove the grille. A. Remove the four grille to radiator suppod fasteners located across the top of the grille and the four fasteners located within the egg crate area of the grille. Page 4509 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 2515 Knock Sensor: Description and Operation Electronic Spark Control Circuit Knock Sensor (KS) Sensor PURPOSE Varying octane levels in today's gasoline can cause detonation (also known as spark knock) in an engine. The Knock Sensor (KS) system has various knock sensors that are used on all engines except the 2.5L. The KS system reduces spark knock (detonation) in the engine. This allows the engine to have a maximum spark advance for improved driveablity and fuel economy. CONSTRUCTION This KS system has three main components: - KS Module. - Knock sensor - ECM OPERATION The knock sensor detects abnormal vibration (spark knocking) in the engine. The knock sensor is mounted in the engine block near the cylinders. The KS module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the Ignition Control (IC) to reduce spark knocking. The KS module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the knock sensor. This allows the ECM to maintain maximum timing advance under various engine load conditions. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards IC to reduce spark knock. Page 4313 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using a torque wrench. 8. Continue tightening pinion nut in small increments until 35-40 inch lbs. of bearing preload is obtained with new bearings or 20-25 inch lbs. of bearing preload is obtained with used bearings, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 4 - Pinion Fig. 5 Drive pinion & bearing shim adjustment 1. Install front pinion bearing cup in carrier using tool J-7817 or equivalent. 2. Install spacer (E) into carrier bore, Fig. 5. 3. Slide rear pinion bearing and cap (F) onto thru bolt (D) and rear bearing into axle housing. 4. Install thru bolt (D), rear bearing and cap (F) into axle housing. 5. Assemble front bearing cone (A) and spacer (B) onto thru bolt. 6. Rotate nut and shaft while increasing torque on nut until a rotational torque of 15-22 inch lbs. is obtained. Rotate thru bolt back and forth when tightening nut to properly seat bearing. 7. Install discs on thru bolt assembly as shown in Fig. 5. Position carrier so dial indicator contact rod is directly over gauging area of gauge plate J-35118-2. Discs must be fully seated in side bearing bores. 8. Install bearing caps over gauge shaft discs, then the cap attaching bolts. torque attaching bolts to 40 ft. lbs. 9. With dial indicator rod contacting gauging area of J-35118-2, rock gauge shaft back and forth until dial indicator measures the greatest deflection, then zero dial indicator. 10. Rotate gauge shaft until shaft does not contact gauge plate, then note measurement. 11. Select correct pinion shim as follows: a. If reusing production pinion, and pinion is marked with a ``+,'' correct shim will have a thickness equal to gauge reading minus amount specified on pinion. b. If reusing production pinion, and pinion is marked with a `` - ,'' correct shim will have a thickness equal to gauge reading plus amount specified on pinion. c. If using a production or service pinion which has no marking, correct shim will have a thickness equal to gauge reading. 12. Install selected pinion shim into carrier, then press rear pinion bearing cup into carrier using tool J-5590 or equivalent. 13. Press rear pinion bearing onto pinion using a bearing installation tool, then install pinion in carrier. 14. Install collapsible spacer and front bearing onto pinion while supporting pinion under head. 15. Install oil seal, companion flange and new nut on pinion, then tighten pinion nut until a rotating torque of 10-25 inch lbs. with new bearings or 5-12 inch lbs. with original bearings is obtained while rotating pinion forwards to seat bearings. 16. If preload is excessive after tightening pinion nut, replace collapsible spacer and repeat steps 14 and 15. Page 416 Vehicle Speed Sensor/Transducer - Cruise Control: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Engine - Tick Or Rattle/Detonation Or Rattle Noise Intermediate Shaft: Customer Interest Engine - Tick Or Rattle/Detonation Or Rattle Noise FILE IN SECTION: 6 - Engine BULLETIN NO.: 23-61-11 DATE: June, 1995 SUBJECT: CPI Engine Noise (Install New Gears/New MEM-CALs) MODELS: 1992 Chevrolet and GMC Truck S/T, M/L Models 1992 Oldsmobile Bravada with 4.3L CPI Engine (VIN W - RPO L35) This bulletin is being revised to update engine scrapping information. Previous divisional publication numbers were: Chevrolet 92-244B-6 GM of Canada 93-6A-121 GMC Truck 92-6A-153A Oldsmobile 92-T-168 CONDITION Some 1992 model year 4.3L CPI engines may exhibit one or both of the following noises: I. A tick or rattle noise at idle or low engine speeds up to 1300 RPM. The noise may occur hot or cold in Park/Neutral or in gear. II. A detonation or rattling type noise under acceleration at engine speeds between 2000 - 2500 RPM. It is usually most noticeable at the shift points under moderate acceleration with the transmission torque converter unlocked. Premium grade fuel does not affect the noise. III. If an engine has both noises (conditions "I" and "II"), follow condition "II" for cause and correction instructions and information. CAUSE I. The most probable cause for the idle tick or rattle (condition I) is due to zero or near zero lash between the balance shaft drive gears. Some gears may feel as if the lash is acceptable but there is most likely an area on one of the teeth which is not meshing properly with the other gear. II. The source of the detonation or rattling type noise under acceleration between 2000 - 2500 RPM (condition II) is the rear balance shaft needle bearing. With some engines, the rear needle bearing is excited by a combination of factors (i.e., engine case, combustion events, balance shaft gear lash, valve train torque reversals, cam chain play, needle bearing clearance, etc.). Important: If there is any question about the proper diagnosis of the noise, call Technical Assistance. The unnecessary customer inconvenience and/or replacement of parts must be avoided. It is important to note that neither noise is a reliability or dependability concern. The noises are a customer pleasability issue only. The life of the engine will not be shortened due to the above causes. CORRECTION I. The following steps should be followed to correct an idle tick noise (condition I). 1. Remove the accessory drive belt. 2. Start the engine and note the noise. If it is still present proceed to step "3"; if not, proceed with diagnosis of accessory drive per the service manual procedures. Important: Do not allow the engine to operate for an extended period of time with the accessory drive belt off. Remember the water pump and fan are not functioning. Overheat will eventually occur. 3. Order GMSPO B/S Gear Kit # 12513234 and W/P; front cover gaskets. Use the following steps to replace the balance shaft gears. Page 5185 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 5075 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 378 Symbol Identification Page 2895 Engine Control Module: Component Tests and General Diagnostics ECM QDR Check Procedure ECM QDR Check Procedure Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Page 7785 Turn And Hazard Lamp Flashers Page 4357 Axle Shaft Assembly: Service and Repair Axle Assembly ROCKWELL REAR AXLE ASSEMBLY 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Housing ROCKWELL REAR AXLE HOUSING 1. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Axle Shaft ROCKWELL REAR AXLE SHAFT 1. Remove hub cap, then install slide hammer adapter into tapped hole in axle flange. 2. Attach slide hammer onto adapter, then remove axle shaft from housing. 3. Install axle shaft, ensuring flange and hub splines align. 4. Install new gasket, position flange to hub, then install attaching bolts and tighten to specifications. Bearing & Cup ROCKWELL REAR WHEEL BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Page 7583 Symbol Identification A/T - Early Converter Clutch Engagement PROM - Programmable Read Only Memory: Customer Interest A/T - Early Converter Clutch Engagement Number: 92-75-7A Section: 7A Date: JAN. 1992 Corporate Bulletin No.: 137107 ASE No.: A2 Subject: EARLY TRANSMISSION CONVERTER CLUTCH APPLY Model and Year: 1992 S/T TRUCKS WITH 4.3L ENGINE AND 4L60 AUTOMATIC TRANSMISSION Condition: Some owners of 1992 S/T trucks with 4.3L (LB4) engines and automatic transmissions may comment on early transmission converter clutch (TCC) engagement, TCC engagement just after the 2-3 upshift, or lack of power. Cause: The torque converter clutch is applied at low speeds during some driving conditions. Correction: To correct this condition install a new calibration PROM which raises the TCC apply speed. This calibration will increase the TCC apply speed on a 1992 vehicle to be similar to a 1991 vehicle. (See below) Part PROM Scanner Number Application Broadcast I.D. 16175285 Federal BARL 5551 16175286 California BARM 5561 Parts are expected to be available on January 27, 1992. In case of limited inventory, parts will be placed on 400 Control to waive VIP surcharges. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation at dealer's expense and all other order types will be placed on backorder until the 400 control is removed. Labor Operation Number: T0500 Labor Time: 0.8 Hour Page 183 Diagnostic Circuit Circuit Description The diagnostic circuit check is an organized approach to identifying a problem created by an electronic engine control system malfunction. It must be the starting point for any driveability complaint diagnosis, because it directs the service technician to the next logical step in diagnosing the complaint. Understanding the chart and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of good parts. Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. This step is a check for the proper operation of the "Service Engine Soon" light. The "SES" light should be "ON" steady. 2. No "SES" light at this point indicates that there is a problem with the "SES" light circuit or the control module control of that circuit. 3. This test checks the ability of the control module to control the "SES" light. With the diagnostic terminal grounded, the "SES" light should flash a Code 12 three times, followed by any trouble code stored in memory. A PROM error may result in the inability to flash Code 12. 4. Most of the diagnostic charts use a Tech 1 to aid diagnosis, therefore, serial data must be available. If a PROM error is present, the control module may have been able to flash Code 12 or 51, but not transmit serial data. 5. Although the control module is powered up, a "Cranks But Will Not Run" symptom could exist because of an control module or system problem. 6. This step will isolate if the customer complaint is a "SES" light or a driveability problem with no "SES" light. See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions for a list of valid codes. An invalid code may be the result of a faulty "Scan" tool, PROM or control module. 7. Comparison of actual control system data with the typical valves is a quick check to determine if any parameter is not within limits. Keep in mind that a base engine problem (i.e., advanced cam timing) may substantially alter sensor values. 8. If the actual data is not within the typical values established, refer to individual component tests. Locations Blower Motor Resistor: Locations Heater Components. On Blower Motor Case Applicable to: Vehicles Less A/C Heater & A/C Components On Blower Motor Case Page 527 Use applicable labor time guide for labor hours. Page 7132 - Wear/cracking/peeling - Discoloration/dye transfer from customer clothing (if discoloration/dye transfer is not removed after using GM Leather and Vinyl Plastic Cleaner, P/N 88861401 (in Canada, P/N 88861409), replace the covers.) Disclaimer Page 6854 Disclaimer Fuel - Pedal Position Lower After Using Cruise Control Accelerator Controls: Technical Service Bulletins Fuel - Pedal Position Lower After Using Cruise Control Number: 92-293-6C Section: 6C Date: OCT. 1992 Corporate Bulletin No.: 266106 ASE No.: A1, A8 Subject: ACCELERATOR PEDAL POSITION IS LOWER AFTER USING CRUISE/MORE EFFORT NEEDED Model and Year: 1991-92 S/T TRUCKS AND WL, G VANS Owners of some 1991 and 1992 S/T and M/L vehicles equipped with 4.3L engines (RPO LB4) or 1991 and 1992 G-vans equipped with 4.3L, 5.0L and 5.7L engines (RPO LB4, L03 and L05) may comment that after using cruise control the accelerator pedal position at idle is lower. Customers may also comment that more effort is needed to use the accelerator pedal. Floor contact by the pedal may also be encountered prior to wide open throttle reducing the performance capability of the vehicle. The above conditions may be the result of the accelerator cable slipping out of the pulley channel on the throttle body (Figure 1). The pulley acts as a cam and is located on the driver's side of the TBI unit. When the cable slips off the pulley, the effective radius of the cam is reduced and more effort is required to depress the pedal. Also the pedal position at idle is lowered. The accelerator cable may slip out of the pulley channel when in cruise control and under the following conditions. -The accelerator cable is kinked, curled, or bent. -A build up of foreign material occurs in the back side of the cable wiper-cap where the cable enters the cable jacket. The foreign material prevents the Warranty - Rail Dust Removal & Chemical Spotting Labor Paint: All Technical Service Bulletins Warranty - Rail Dust Removal & Chemical Spotting Labor File In Section: Warranty Administration Bulletin No.: 72-05-11 Date: December, 1997 WARRANTY ADMINISTRATION Subject: Clarification of Rail Dust Removal (A5575-A5580) and Chemical Spotting (A5541-A5544) Labor Operations Models: All Past and Future Passenger Cars and Light Duty Trucks The purpose of this Warranty Administration Bulletin is to clarify the usage, limits and guidelines for the proper use of the above subject labor operations. The above subject labor operations were introduced to correct paint imperfections caused by fallout that occurred either during shipment to the dealer or within the first 12 months or 12,000 miles (20,000 kms) of vehicle ownership. GM vehicle owners are informed that although no defect in the factory applied paint causes this, GM will repair, at no charge to the owner, the surfaces of new vehicles damaged by fallout condition within 12 months or 12,000 miles (20,000 kms) whichever occurs first. Effective with repair orders dated on or after December 1, 1997, labor operations A5575-A5580 Rail Dust Removal and A5541 through A5544 Chemical Spotting will be limited to within the first 12 months or 12,000 miles of the Base Vehicle Warranty (20,000 kms) whichever occurs first. Crankshft & Bearing Specs Crankshaft & Bearings Page 4351 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum ROCKWELL REAR WHEEL BEARINGS Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. 5. Pull hub and drum straight off axle housing. Speedometer - Registers When Vehicle is Stationary Vehicle Speed Sensor: All Technical Service Bulletins Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. Page 5217 Symbol Identification Locations Electronic Spark Control (ESC) Module Page 5608 Fig. 1 Troubleshooting power steering system Page 8190 Hazard Warning Flasher: Locations Hazard Lamp Flasher Less Digital Instrument Cluster LH Side Of Instrument Panel. On Fuse Block Applicable to: Except Bravada Digital Instrument Cluster Page 7324 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 62 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 8133 Stoplamps Page 575 Headlamp Switch: Service and Repair 1. Disconnect battery ground cable. 2. Remove headlamp switch trim plate and switch assembly attaching screws. 3. Disconnect electrical connectors from headlamp switch, then remove switch assembly from dash panel. 4. Reverse procedure to install. Page 670 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Page 4701 Brake Shoe: Adjustments These brakes have self adjusting shoe mechanisms that ensure correct lining-to-drum clearances at all times. The automatic adjusters operate only when brakes are applied as vehicle is moving rearward. Although the brakes are self-adjusting, an initial adjustment is necessary after brake shoes have been relined or replaced, or when length of star wheel adjuster has been changed during some other service operation. Frequent usage of an automatic transmission forward range to halt reverse vehicle motion may prevent automatic adjusters from functioning, thereby inducing low pedal heights. Should low pedal heights be encountered, it is recommended that numerous forward and reverse stops be made until satisfactory pedal height is obtained. If a low pedal height condition cannot be corrected by making numerous reverse stops (provided hydraulic system is free of air), the self-adjusting mechanism is not functioning. Therefore it will be necessary to remove brake drum, clean, free up and lubricate adjusting mechanism. Then adjust brakes as follows, being sure parking brake is fully released. Upon initial adjustment, a lanced area in the brake backing plate must be removed prior to adjusting brakes. To remove lanced area, knock out with a suitable hammer and punch, then remove brake drum to clear any metal particles caught inside the brake compartment. Install brake drum and proceed with adjustment. After adjustment is complete, install brake adjustment hole cover to prevent entry of water and dirt. 1. Turn brake adjusting screw to expand shoes until wheel can just be turned by hand. 2. Using a suitable tool to hold actuator lever off adjuster, back adjuster off 24 notches. If shoes still drag, back off one or two additional notches. NOTICE: Brakes should be free of drag when adjuster has been backed off approximately 12 notches. Heavy drag at this point indicates tight parking brake cables. 3. Install adjusting hole cover on brake drum or backing plate. 4. Check parking brake adjustment. Page 8212 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 4109 Valve Body: Technical Service Bulletins A/T - Evaluating Peened Spacer Plates Number: 91-396-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 177120 Subject: EVALUATING PEENED SPACER PLATES Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSAXLES AND TRANSMISSIONS (EXCEPT GEO) TRANSMISSIONS APPLICATIONS: All HYDRA-MATIC Automatic Transmissions and Transaxles SUBJECT: Evaluating Peened Spacer Plates (Service Information) TRANSMISSION MODELS: All VEHICLE APPLICATIONS: All Vehicles Using HYDRA-MATIC Automatic Transmissions and Transaxles Bulletin Covers: Some spacer plate peening is considered acceptable and preferred because it can help seat the check ball. This bulletin will help you decide if a spacer plate needs to be replaced due to a peening condition. Service Procedure: The following two procedures can help determine if the spacer plate can be reused. The following must be performed at all check-ball locations. Figure 1 1. The spacer plate must be inspected 100% for raised material on the opposite side of the check-ball seat (see Figure 1). If the material on the opposite side is raised, the peening is too severe and the spacer plate must be replaced. Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Level Sending Unit: Customer Interest Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 6528 Disclaimer Page 3582 Ignition Control Module: Service and Repair Typical Distributor Components REMOVE OR DISCONNECT NOTE It is not necessary to remove ignition distributor assembly from engine. - Distributor cap and rotor. - Connectors from module. - Two module attaching screws. - Lift module from housing and remove. INSTALL OR CONNECT NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. - Module onto housing. - Module attaching screws. Tighten to 2 Nm (18 lb.in.) - Connectors to module. - Rotor and cap. Page 3869 Page 3423 For vehicles repaired under warranty use: Page 6660 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 5258 Figure 7 Figure 8 Figure 9 Figure 10 Page 4248 Side Gear (RH) Clutch Fig. 5 Exploded View Of Eaton Locking Differential 1. Remove shim and disc pack from gear keeping components in order. 2. Inspect discs and guide clips and replace as needed. 3. Inspect side gear and shim. If either component is scored or excessively worn, inspect case and replace entire assembly if case is defective. If either side gear or shim must be replaced, shim thickness must be determined as outlined in SIDE GEAR SHIM SELECTION. 4. Alternately assemble splined and eared discs on side gear hub as shown in Fig. 5. If components are reused, they must be installed in original position. 5. Install original shim or new shim of equal thickness. EGR Intake Manifold Cleaning EGR Valve: Service and Repair EGR Intake Manifold Cleaning PROCEDURE WARNING Appropriate eye protection should be worn when cleaning the EGR system to prevent injury to eyes. CAUTION When cleaning intake manifold EGR passages, care should be taken to ensure that all loose particles are completely removed to prevent them from clogging the EGR valve or from being ingested into the engine, as damage to system or engine may occur. - Remove throttle body. - Disconnect vacuum hose or electrical connector from EGR valve, then remove EGR valve to manifold retaining bolts and valve. - Remove deposits from EGR ports by hand using a suitable drill bit and screwdriver. - Brush small deposits down EGR port into passages, then using compressed air, blow ports clean. Solvents should not be used to clean EGR valve or passages, since damage to system may result. - Install EGR valve, using new gasket. - Install throttle body. Page 7290 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 1284 Fuse Block: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 5766 Wheel Bearing: Adjustments Four Wheel Drive - 4WD FRONT WHEEL BEARINGS ADJUSTMENT 4 X 2 MODELS 1. Raise and support front of vehicle. 2. Remove hub dust cover, then the cotter pin. 3. While rotating wheel assembly in forward direction, torque spindle nut to specification to fully seat the bearings. 4. Loosen nut to the ``just loose'' position, then tighten the spindle nut finger tight. 5. If either spindle hole does not line up with a spindle nut slot, back off spindle nut not more than 1/2 nut flat. 6. Install new cotter pin, then measure hub endplay. Endplay should be .001-.005 inches when properly adjusted. 7. Install hub dust cover and lower vehicle. 4 X 4 MODELS These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ROCKER ARM NUT TORQUE Valve Rocker Arm Nuts ....................................................................................................................... ................................................ 27 Nm (20 lb. ft.). Page 3217 Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards The following gasoline brands meet the TOP TIER Detergent Gasoline Standards in all octane grades : Chevron Canada (markets in British Columbia and western Alberta) - Shell Canada (nationally) - Petro-Canada (nationally) - Sunoco-Canada (Ontario) - Esso-Canada (nationally) What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency and no metallic additives. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent recommendations of Canadian standards and does not contain metallic additives, which can damage vehicle emission control components. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began in the U.S. and Canada on May 3, 2004. Some fuel marketers have already joined and introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: BMW, General Motors, Honda, Toyota, Volkswagen and Audi. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. In the U.S., government regulations require that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In Canada, gasoline standards recommend adherence to U.S. detergency requirements but do not require it. In fact, many brands of gasoline in Canada do not contain any detergent additive. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required or recommended, and no metallic additives are allowed. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency and the intentional addition of metallic additives is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Clean engines help provide optimal fuel economy and engine performance, and also provide reduced emissions. Also, the use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Who should use TOP TIER Detergent Gasoline? All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. More information on TOP TIER Detergent Gasoline can be found at this website, http://www.toptiergas.com/. Page 5005 Clutch Start Switch: Service and Repair Fig. 3 Clutch Start Switch Installation 1. Remove lower I/P trim panel. 2. Remove clutch start switch electrical connector. 3. Remove clutch start switch from clutch pedal. 4. Reverse procedure to install, Fig. 3. Page 6894 Symbol Identification Page 3435 Idle Air Control (IAC) System Circuit Circuit Description: The ECM controls idle rpm with the IAC valve. To increase idle rpm, the ECM moves the IAC valve away from it's seat, allowing more air to pass by the throttle plate. To decrease rpm, it moves the IAC valve toward it's seat, reducing air flow by the throttle plate. A Tech 1 "Scan" tool will read the ECM commands to the IAC valve in counts. The higher the counts, the more air allowed (higher idle). The lower the counts, the less air allowed (lower idle). Test Description: Number(s) below refer to circled number(s) on the diagnostic chart. 1. The IAC tester is used to extend and retract the IAC valve. Valve movement is verified by an engine speed change. If no change in engine speed occurs, the valve can be retested when removed from the throttle body. 2. This step checks the quality of the IAC movement in Step 1. Between 700 rpm and about 1500 rpm, the engine speed should change smoothly with each flash of the tester light in both extend and retract. If the IAC valve is retracted beyond the control range (about 1500 rpm), it may take many flashes in the extend position before engine speed will begin to drop. This is normal on certain engines, fully extending the IAC may cause engine stall. This may be normal. 3. Steps 1 and 2 verified proper IAC valve operation while this step checks the IAC circuits. Each lamp on the node light should flash red and green while the IAC valve is cycled. While the sequence of color is not important if either light is "OFF" or does not flash red and green, check the circuits for faults, beginning with poor terminal contacts. IAC VALVE RESET PROCEDURE: ^ Ignition "OFF" for 10 seconds. ^ Start and run engine for 5 seconds. ^ Ignition "OFF" for 10 seconds. Diagnostic Aids: A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be overcome by the IAC valve. Out of control range IAC Tech 1 "Scan" tool counts will be above 60 if idle is too low, and zero counts if idle is too high. The following checks should be made to repair a non-IAC system problem. ^ Vacuum Leak (High Idle) - If idle is too high, stop the engine. Fully extend (low) IAC with tester. Start engine. If idle speed is above 800 rpm, locate and correct vacuum leak including PCV system. Also cheek for binding of throttle blade or linkage. ^ System too lean (High Air/Fuel Ratio) - The idle speed may be too high or too low. Engine speed may vary up and down and disconnecting the IAC valve does not help. Code 44 may be set "Scan" 02 voltage will be less than 300 mV (.3 volt). Check for low regulated fuel pressure water in the fuel or a restricted injector. ^ System too rich (Low Air/Fuel Ratio), - The idle speed will be too low. "Scan" tool IAC counts will usually be above 80. System is obviously rich and may exhibit black exhaust smoke. Tech 1 "Scan" tool 02 voltage will be fixed above 800 mV (.8 volt). Check for high fuel pressure, leaking or sticking injector. Silicone contaminated 02 sensors "Scan" voltage will be slow to respond. ^ Throttle body - Remove IAC and inspect bore for foreign material. ^ A/C Compressor - Refer to "A/C Diagnosis" if circuit is shorted to ground. If the relay is faulty, idle problem may exist. ^ If intermittent poor driveability symptoms are resolved by disconnecting the IAC, carefully recheck connections, valve terminal resistance, or replace IAC. Page 1652 1. Disconnect battery. 2. Drain coolant. 3. Remove fan shroud. 4. Remove accessory drive belt. 5. Remove fan. 6. Remove the water pump. 7. Remove crankshaft pulley and harmonic balancer. 8. Remove transmission torque converter cover. Let it lie on top of exhaust crossover pipe. 9. Drop the oil pan by leaving the rear two nuts on the crankshaft seal studs about 1/4 inch from tight. The two studs will stabilize the oil pan and the oil will not have to be drained. 10. Remove the front cover. 11. It is recommended that the engine be turned over by hand so the crankshaft and camshaft sprocket timing marks are dot to dot. 12. Loosen the small diameter balance shaft gear bolt. This is the driven gear and has a TORX drive bolt. 13. Remove the camshaft sprocket by taking off the lock nut first, then the two bolts. 14. Remove the large diameter balance shaft (drive) gear. 15. Remove the small diameter balance shaft driven gear. 16. Clean all sealing surfaces, removing all old gasket material. Installation of new matched set balance shaft gears: 1. Install driven gear (small diameter gear) and bolt finger tight. 2. Install and align drive gear dot to dot with timing mark of the driven gear. 3. Install drive gear stud to 16 Nm (12 lb.ft.) to ensure the shoulder of the stud is below the counter bore in the gear. 4. Install camshaft sprocket and chain. Ensure their timing is correct. If the camshaft and crankshaft have not been disturbed, the crankshaft and camshaft sprockets should be dot to dot. 5. Install the camshaft sprocket nut and bolts. Torque to 28 Nm (21 lb.ft.). 6. Torque driven balance shaft gear bolt to 20 Nm (15 lb.ft.) plus an additional 35° using a J 3660 degree meter, torque driver. 7. At this point, the gear change is complete. Follow the removal steps in reverse order to install the remaining components. Consult the service manual for torque specifications. CORRECTION II. The following steps should be followed to diagnose the detonation type rattle noise which occurs between 2000 - 2500 RPM under load (condition II): 1. Ensure the ESC (Electronic Spark Control) system is working properly. Refer to the ELECTRONIC SPARK CONTROL section of the LIGHT DUTY TRUCK FUEL AND EMISSIONS section of the service manual. This section includes an "ELECTRONIC SPARK CONTROL SYSTEM CHECK" with a fault tree for the 4.3L CPI engine. 2. Operate the vehicle with premium fuel. If the noise is eliminated, the noise is not coming from the balance shaft rear needle bearing. Refer to the DRIVEABILITY SYMPTOMS section of the LIGHT DUTY TRUCK FUEL AND EMISSIONS service manual. BRAVADA ONLY: Refer to Bravada service manual section 6E. 3. If the ESC system is functioning properly and the noise is still audible using premium fuel, the source of the noise is most probably the rear Page 2165 Coolant: Technical Service Bulletins Cooling System - Use of Recycled Engine Coolant Number: 91-235-6B Section: 6B Date: MARCH 1991 Corporate Bulletin No.: 116201 Subject: USE OF RECYCLED ENGINE COOLANT Model and Year: ALL PASSENGER CARS AND TRUCKS With the current emphasis on environmental issues and disposal of waste, significant attention is being given to the recycling of engine coolant. Many coolant recycling systems are being aggressively marketed today, ranging from very complex distillation (stationary) to straightforward filtration (mobile). As stated in previous service bulletins, General Motors does not endorse the use of recycled engine coolants in our products at this point in time. Recycling engine coolant is a very complex procedure and consequently will require a significant amount of research to determine which of the many processes is acceptable by General Motors. While we understand the growing concern being placed on (spent) engine coolant disposal, it is imperative that the quality of engine coolants being used in General Motors vehicles is not affected in any way. General Motors is addressing the issue of recycled engine coolants for the combined benefit of our dealers, vehicle owners, and the environment. Over the next several months General Motors will conduct an experiment designed to evaluate both distillation and "on-site" recycling processes. The results of this experiment will be provided to all dealers (spring, 1991) and will outline which process(es) is acceptable to General Motors. It is essential that recycled engine coolant not be used in any General Motors products as communicated in previous bulletins. Page 4942 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 3480 Turn ignition switch to "ON" position for two seconds, then turn to "OFF" position for ten seconds. Again turn ignition switch to "ON" position and check for leaks around gaskets and fuel line couplings. Page 2324 Coolant Level Indicator Lamp: Service and Repair This lamp will be illuminated when engine coolant level in the radiator drops below a pre-determined level. To turn lamp "OFF," check cooling system, then add coolant to bring system to proper level. Page 7599 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 5230 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 8317 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 4091 Transmission Cooler: Technical Service Bulletins A/T - Cooler Replacement/Flushing BULLETIN NO: 93-7A-97 SECTION: 7A Automatic Transmission NUMBER: 14 CORPORATE REFERENCE NO: 367102R DATE: July, 1993 SUBJECT: Information on Automatic Transmission Cooler Replacement MODELS: 1993 and Prior Light Duty Trucks Equipped with Automatic Transmissions When inspection of an inoperative automatic transmission reveals metal material in the oil pan, the transmission oil cooler (located in the radiator end tank) must be replaced. The cooler lines must also be flushed to prevent any debris from entering the transmission oil cooler or the transmission. If inspection reveals friction material or fluid contamination (but no metal), the transmission cooler must be flushed and a flow check MUST be performed. It is essential to flush the cooler after SRTA installation, major overhaul, in the case of pump or torque converter replacement, or when fluid contamination is suspected. Use Kent-Moore tool J35944 and solvent J35944-20 to flush the cooler. Follow the instructions published in each Service Manual, Section 7A, On Vehicle Service, Transmission Cooler Flushing. SERVICE PARTS INFORMATION Refer to section 4.128 of the appropriate GMSPO parts catalog for transmission oil cooler applications. WARRANTY INFORMATION For vehicles repaired under warranty, use: Note: If transmission is to be replaced with SRTA, do not use ADD condition H (To Replace Transmission Oil Cooler - 0.7 hr). Labor Operation K7000 (Transmission Assembly Replace) already includes 0.7 hr (for transmission cooler flush). Page 7392 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 6904 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 8281 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 2169 Coolant: Specifications Less A/C 12.1 qt (US) With A/C 12.1 qt (US) Page 2698 Spark Plug Wire: Description and Operation CONSTRUCTION The spark plug/coil secondary wiring is a carbon impregnated cord conductor encased in a rubber jacket. The 7-mm wire used on the 2.5L and 2.8L engines and the 8-mm wire used on the 3.1L, 4.3L, 5.0L, 5.7L and 7.4L has an outer layer of silicone. The silicone jacket withstands very high temperature and also provides an excellent insulator for the higher voltage of the electronic ignition system. The silicone spark plug boots form a tight seal on the plugs and distributor cap. CAUTION - Care should be exercised when connecting a timing light or other pick-up equipment. - Do not force anything between the boot and wiring. - Do not pierce the secondary wire insulation. - Use only equipment with an inductive pickup to check for spark plug firing. - Do NOT pull on the wire to remove. The boot should be twisted 1/2 turn before removing. Pull on the boot, or use a tool designed for this purpose. Page 769 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Locations Distributor And Coil 4.3W Page 1047 Heater Hose: Service and Repair Engine Heater Hose Routing (w/ Air Conditioning) The heater inlet hose is routed from the intake manifold to the inlet pipe of the heater core. The heater outlet hose is routed from the outlet pipe of the heater core to the inlet fitting of the coolant pump. Hoses are attached at each end with screw-type clamps. REMOVE OR DISCONNECT 1. Engine coolant. - Drain enough coolant into a clean container to lower the coolant level below the level of the lowest heater hose fitting. 2. Inlet and outlet hoses (72 and 70) at fittings. - Loosen the clamp screws enough to slide the clamps away from the fittings on the inlet and outlet hoses (72 and 70). - Remove the hose end by twisting and pulling. NOTICE: The heater core can be damaged if too much force Is applied on the core tubes During removal If the heater hose will not come off easily, cut off the hose forward of the heater core tube. Cut the hose remaining on the core tube lengthwise to remove it. 3. Hose Support clamps, brackets and/or retainers, as necessary. 4. Heater hose(s) (72 and 70) and clamps. INSTALL OR CONNECT 1. Healer hose(s) (72 and 70) and clamps. 2. Hose support clamps, brackets and/or retainers, if removed. 3. Inlet and outlet hoses (72 and 70) to fittings. Page 5267 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 6744 Symbol Identification Page 7167 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 1341 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 4827 Hydraulic Brake Booster: Service and Repair Bleeding Brake Boosters (Bendix Type) Hydro-Boost 1. Fill oil reservoir to proper level and let stand at least two minutes. 2. Start engine and run momentarily. 3. Add oil as necessary. 4. Repeat above procedure until oil level remains constant after running engine. 5. Raise and support front of vehicle. 6. Turn wheels left and right, lightly contacting stops. 7. Add oil as necessary. 8. Lower vehicle. 9. Start engine and depress brake pedal several times while rotating steering wheel from stop to stop. 10. Turn engine off, then pump brake pedal four or five times to deplete accumulator pressure. 11. Check oil level, filling as necessary. 12. If oil is extremely foamy, allow vehicle to stand several minutes with engine off, then repeat entire procedure. Hydro-Boost II 1. Fill power steering pump until fluid level is at base of pump reservoir neck. 2. Disconnect 12 volt wire from injection pump or distributor, then crank engine for several seconds. Do not start engine. 3. Check fluid level, adding as necessary. 4. Connect 12 volt wire and start engine. 5. Turn steering wheel from stop to stop, then turn off engine. 6. Depress brake pedal four or five times to deplete accumulator vacuum. 7. Check fluid level, adding as necessary. 8. Start engine, turn steering wheel from stop to stop. Turn engine off, and check fluid level. 9. If fluid is extremely foamy, stop engine and let vehicle stand for one hour, then check fluid level, adding as necessary. Page 8651 Disclaimer Page 6931 Disclaimer Page 4580 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 7055 Page 6837 Front Door Interior Handle: By Symptom Technical Service Bulletin # 461601 Date: 940401 Interior Door Handle Spring - Early Breakage Group Ref.: Body Bulletin No.: 461601 Date: April, 1994 INFORMATION SUBJECT: INTERIOR DOOR HANDLE SPRING BREAKAGE MODELS: 1990-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1990-94 CHEVROLET AND GMC TRUCK S/T UTILITIES 1991-94 OLDSMOBILE BRAVADA Some vehicles may be found to have front side door interior door handles with broken springs. This condition tends to be associated with vehicles that experience high (frequent) usage of the door handle mechanism. To enhance spring durability, production vehicles are now receiving door handle assemblies with lithium grease added to the spring. The durability of replacement door handles obtained from GMSPO can be increased by adding lithium based lubricant to the door handle spring. The lubricant should be applied so that it works into and between the spring coils. This will allow the coils to move past each other freely, reducing spring breakage. SERVICE PARTS INFORMATION: P/N Description Qty Procure Locally Lithium Based As Needed Lubricant Technical Service Bulletin # 461601 Date: 940401 Interior Door Handle Spring - Early Breakage Group Ref.: Body Bulletin No.: 461601 Date: April, 1994 INFORMATION SUBJECT: INTERIOR DOOR HANDLE SPRING BREAKAGE MODELS: 1990-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1990-94 CHEVROLET AND GMC TRUCK S/T UTILITIES 1991-94 OLDSMOBILE BRAVADA Some vehicles may be found to have front side door interior door handles with broken springs. This condition tends to be associated with vehicles that experience high (frequent) usage of the door handle mechanism. To enhance spring durability, production vehicles are now receiving door handle assemblies with lithium grease added to the spring. The durability of replacement door handles obtained from GMSPO can be increased by adding lithium based lubricant to the door handle spring. The lubricant should be applied so that it works into and between the spring coils. This will allow the coils to move past each other freely, reducing spring breakage. SERVICE PARTS INFORMATION: P/N Description Qty Procure Locally Lithium Based As Needed Lubricant Page 3872 Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Page 6906 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Windshield/A Pillar - Pop Noise Diagnosis Windshield: Customer Interest Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Locations Horn Relay Installation Door Jamb Switch Door Switch: Locations Door Jamb Switch On A-Pillars Page 3661 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 8806 Wiper Motor: Service and Repair FRONT 1. Disconnect battery ground cable. 2. Remove windshield wiper arms. 3. Remove cowl vent and grille. 4. Loosen, but do not remove transmission drive link to motor crank arm attaching nuts, then disconnect drive link from motor crank arm. 5. Disconnect motor electrical connector and remove attaching bolts. 6. Remove motor by rotating up and outward. 7. Reverse procedure to install. Torque motor attaching bolts to 49-75 inch lbs. Fig. 11 Windshield Wiper Motor Removal (Rear) REAR Refer to Fig. 11, for wiper motor replacement. 1. Disconnect battery ground cable. 2. Remove three retainer screws and cover from wiper motor. 3. Remove three roof trim panel screws, then the trim panel. 4. Disconnect washer hose and electrical connector at wiper motor. 5. Remove wiper arm assembly from wiper motor. 6. Support glass on right side. 7. Remove nut, spacer and flat seal from wiper motor. 8. Remove wiper motor hinge bolt from hinge assembly, then the wiper motor. 9. Reverse procedure to install noting the following: a. Torque wiper motor hinge bolt to 54 inch lbs. b. Torque wiper motor nut to 54 inch lbs. Locations Brake Vacuum Release Valve: Locations Cruise Control Components, Near Steering Column. Page 6120 Control Cable REMOVE OR DISCONNECT 1. Screws (64). 2. Control assembly (63). NOTICE: Pull control assembly (63) out of the instrument panel far enough to reach the control cable assembly ends arid the blower switch electrical connector. 3. Electrical connection (82). 4. Control cables (60 and 65). 5. Blower switch if necessary. NOTICE: Remove the blower switch knob and spring clip, and remove the blower switch. Inspect - Electrical terminals for corrosion. Remove the corrosion or replace the component as necessary. - Temperature and mode levers for freedom of movement. Lubricate, repair or replace as necessary. - Control cable assemblies for kinks, binding and other damage. Repair or replace as necessary. INSTALL OR CONNECT 1. Heater blower switch if removed. - Hold the blower switch in position and install the spring clip. Page 1085 Disclaimer Page 8200 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 6411 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Page 5120 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 5088 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 4800 - Brake fluid which is contaminated with air or water will significantly add to the amount of pedal travel. - Pure DOT 3 (or 4) brake fluid is incompressible (allowing for a solid, firm pedal). A small amount of air trapped in the brake fluid will require extra effort from the master-cylinder to compress it, resulting in a soft and spongy pedal. - During prolonged or severe braking the brake fluid temperature can rapidly rise above 212 degrees F. When this occurs any water in the brake fluid will boil into steam (which is compressable) and create a soft and spongy pedal. Rear Brake Shoe Adjustment Drum brake system utilize return springs to pull the shoes away from the drums when not in use. The amount of distance the shoes have to extend to meet the drums greatly affects the amount of pedal travel. - Shoes/Linings which are badly out of adjustment can by themselves result in a brake pedal sinking all the way to the floor NOTE: Improperly adjusted rear shoes/linings also affect the parking brake. Calipers Excessive rotor wobble caused by a warped rotor or loose/worn wheel bearings can knock the caliper piston further inward from its normal resting position. This results in additional pedal travel required to extend the piston and apply the brakes. Drum Expansion Drums which are worn past their "Discard" thickness are prone to expanding outwards into an oval shape during heavy braking. This drum expansion results in additional brake pedal travel. Brake Fade During prolonged or severe braking, the amount of pedal effort/travel required to slow the vehicle increases as the ability of the brakes to dissipate heat decreases. - As the brake linings heat up, their "coefficient of friction" is reduced (they become slicker). As the coefficient of friction is reduced, more hydraulic pressure is required to stop the vehicle. More hydraulic pressure results in more heat which then results in more pedal fade. - As the brake linings, rotors, and drums begin to wear, their ability to absorb and release heat is reduced significantly. This makes worn brakes more prone to "pedal fade". NOTE: Prior to replacing a master-cylinder, verify the entire brake system is functioning properly. Page 1541 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Page 7213 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7681 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 5451 Convenience Center (with Digital Cluster) Page 6098 Push On Fan Assembly Procedure INSTALL OR CONNECT 1. Press fan onto shaft (see accompanying figure). - Grasp fan by dome and apply hand pressure to fan dome, insert fan on motor shaft until slightly seated on shaft. - Place fan and motor on a combination of 10mm x 3/8" drive socket and 1/2" x 3/8" reducer (see accompanying figure). - While steadying the fan and motor, apply steady force to rear of motor shaft using a drill press or small arbor press and pin. Adjust - Fan cage, using spacers, to a clearance of 5.5mm (0.22 inches) to motor mount plate. 2. Blower motor and fan assembly. - Check circuit operation. Without A/C Page 2286 Engine Compartment Components Front Of Engine Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 HP Engine STD Engine Locations Junction Block Wiring Page 3267 Fuel Filler Cap: Service and Repair If a fuel tank filler cap requires replacement, use only a cap with the same features. Failure to use the correct cap can result in a malfunctioning of the evaporative system. Page 6346 Heater Hose: Service and Repair Engine Heater Hose Routing (w/ Air Conditioning) The heater inlet hose is routed from the intake manifold to the inlet pipe of the heater core. The heater outlet hose is routed from the outlet pipe of the heater core to the inlet fitting of the coolant pump. Hoses are attached at each end with screw-type clamps. REMOVE OR DISCONNECT 1. Engine coolant. - Drain enough coolant into a clean container to lower the coolant level below the level of the lowest heater hose fitting. 2. Inlet and outlet hoses (72 and 70) at fittings. - Loosen the clamp screws enough to slide the clamps away from the fittings on the inlet and outlet hoses (72 and 70). - Remove the hose end by twisting and pulling. NOTICE: The heater core can be damaged if too much force Is applied on the core tubes During removal If the heater hose will not come off easily, cut off the hose forward of the heater core tube. Cut the hose remaining on the core tube lengthwise to remove it. 3. Hose Support clamps, brackets and/or retainers, as necessary. 4. Heater hose(s) (72 and 70) and clamps. INSTALL OR CONNECT 1. Healer hose(s) (72 and 70) and clamps. 2. Hose support clamps, brackets and/or retainers, if removed. 3. Inlet and outlet hoses (72 and 70) to fittings. Speedometer - Registers When Vehicle is Stationary Speedometer Head: All Technical Service Bulletins Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. Page 1923 Intake Manifold: Description and Operation The intake manifold is made up of the upper and lower manifold assemblies. The upper manifold assembly is a variable tuned split plenum design that includes an intake manifold tuning valve, Manifold Absolute Pressure (MAP) sensor, TP sensor and an air inlet that is fitted with a throttle valve. This assembly replaces the individual conventional throttle body assembly and plenum components. The throttle valve is used to control air flow into the engine, thereby, controlling engine output. The throttle valve is opened by the vehicle operator, through the accelerator controls. During engine idle, the throttle valve is almost closed and air flow control is handled by the Idle Air Control (IAC) valve. Vacuum ports are located above and below the throttle valve to generate vacuum signal needed by various components. The nonadjustable, throttle shaft-driven, Throttle Position (TP) sensor is attached to the upper manifold assembly opposite the throttle cam lever. The lower manifold is a single casting that houses the CMFI injector assembly, fuel inlet and return tube fitting assemblies, and provisions are provided to accommodate the linear EGR and Engine Coolant Temperature (ECT) sensor. Page 8398 Figure 7 Figure 8 Figure 9 Figure 10 Page 84 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 2288 Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Switch HP Engine LH Front Side Of Engine Front Of Intake Manifold Applicable to: 1992 4.3L/V6-262 HP Engine STD Engine Locations Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Page 6241 Door Jamb Switch Door Switch: Locations Door Jamb Switch On A-Pillars Interior - Itch Noise From Windshield Pillar Area Dashboard / Instrument Panel: Customer Interest Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 7238 Cruise Controller: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 2265 Parts Information Parts are currently available from GMSPO. Page 8609 Front Door Trim Panel Components NOTE: Images shown are for manual windows, power windows are similar. Page 4502 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 418 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Service and Repair Axle Beam: Service and Repair Fig. 5 Rear Suspension (Left Side) Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and place jack stands under frame side rails. Position a jack under the rear axle housing and raise slightly to support axle assembly. 2. Remove rear wheels and drums then disconnect shock absorbers from anchor plates. 3. Scribe reference marks between driveshaft and pinion flange for use during reassembly, then disconnect driveshaft and position aside. 4. Disconnect brake lines from junction block and backing plates, then remove junction block attaching bolt and position aside. 5. Remove backing plates. 6. Remove U-bolts and anchor plates, Fig. 5. 7. On 1988-93 models, disconnect vent hose from axle housing. 8. Lower rear axle assembly, then remove lower spring shackle bolts. 9. Remove rear axle assembly. 10. Reverse procedure to install. Torque shock absorber nut, U-bolt nuts and lower spring shackle bolts to specification. Page 2777 ECM QDR Check Procedure A/T - Cracked Case Diagnosis Case: Technical Service Bulletins A/T - Cracked Case Diagnosis Bulletin No.: 02-07-30-024B Date: August 18, 2005 INFORMATION Subject: Diagnosis of Cracked or Broken Transmission Case Models: 2006 and Prior Cars and Light Duty Trucks 2006 and Prior HUMMER H2 2006 HUMMER H3 2005-2006 Saab 9-7X with 4L60/4L60-E/4L65-E or 4L80-E/4L85-E or Allison(R) Series 1000 Automatic Transmission Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 02-07-30-024A (Section 07 - Transmission/Transaxle). Diagnosing the cause of a cracked or broken transmission case requires additional diagnosis and repair or a repeat failure will occur. A cracked or broken transmission case is most often the result of abnormal external torsional forces acting on the transmission case. If none of the conditions listed below are apparent, an internal transmission component inspection may be required. Repairs of this type may be the result of external damage or abuse for which General Motors is not responsible. They are not the result of defects in materials or workmanship. If in doubt, contact your General Motors Service Representative. The following items should be considered: ^ It is important to inspect the vehicle for signs of an out of line condition, impact damage or foreign material to the following components: - The transmission - The engine mounts - The transmission rear mount and crossmember - Vehicle frame damage that alters the front to rear alignment of the driveshaft - The driveshafts (both front and rear) - The wheels (caked with mud, concrete, etc.) - The tires (roundness, lack of cupping, excessive balance weights) - The transfer case (if the vehicle is 4WD) ^ A worn or damaged driveshaft U-Joint has shown to be a frequent cause of transmission case cracking, especially on vehicles that see extended periods of highway driving. Always inspect the U-joint condition when diagnosing this condition. ^ For driveshaft damage or imbalance, Inspect the driveshafts (both front and rear) for dents, straightness/runout or signs of missing balance weights. Also, inspect for foreign material such as undercoat sprayed on the driveshaft. ^ The driveshaft working angles may be excessive or non-canceling, especially if the vehicle carrying height has been altered (lifted or lowered) or if the frame has been extended or modified. ^ Damaged or worn upper or lower rear control arms or bushings. ^ A rear axle that is not seated in the rear spring properly (leaf spring vehicles). ^ Broken rear springs and or worn leaf spring bushings. Page 3680 For vehicles repaired under warranty use: A/C - Erratic HVAC Operation & Self Diagnostic Blinks Air Conditioning Indicator Lamp: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Page 5960 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Component Locations Power Window Switch: Component Locations Rear Window Release Solenoid In Center Of Endgate 2 Door Rear Window Release Components. Below Cigar Lighter Applicable to: 2Door Blazer & Jimmy 4 Door Page 7639 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 4884 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Diagram Information and Instructions Relay Box: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 3058 Speed Sensor And Backup Lamp Switch Wiring - Two-Wheel Drive Models Locations EGR Valve Position Sensor: Locations Engine Wiring, LH Side Page 5325 For vehicles repaired under warranty, use the table. Disclaimer Page 4928 Symbol Identification Tires (Front) - Irregular Wear Tires: All Technical Service Bulletins Tires (Front) - Irregular Wear Number: 91-26-3E Section: 3E Date: June 1990 Corp. Bulletin No: 053501 Subject: FRONT TIRE WEAR Model and Year: 1982-91 LIGHT DUTY TRUCKS (REAR WHEEL DRIVE) THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-12-3E. THE KILOMETERS HAVE BEEN TRANSLATED INTO MILES. ALL COPIES OF 91-12-3E SHOULD BE DISCARDED. Rear wheel drive trucks, equipped with All Season and/or On-Off road tires may exhibit irregular wear of; the front tires. Small amounts of irregular wear is considered normal and is not necessarily a result of incorrect alignment. Incorrect alignment (especially toe) may result in premature wear of the front tires, however agressive cornering may also have a similar effect. Drive axle tires are much less prone to irregular wear, therefore they should not be considered for comparison of wear to non-drive axle tires. The rate of irregular wear is also dependent upon the depth of tread. New tires are more prone to irregular wear, so it is essential that tires are rotated at the proper intervals to normalize the wear. Page 2054 6. Remove the crankshaft sprocket. 7. Remove crankshaft sprocket key. INSTALLATION 1. Install the key into the crankshaft keyway. 2. Use the crankshaft balancer installer to install the crankshaft sprocket. 3. Install the camshaft sprocket and timing chain. Engine - GM dexos 1 and dexos 2(R) Oil Specifications Engine Oil: Technical Service Bulletins Engine - GM dexos 1 and dexos 2(R) Oil Specifications INFORMATION Bulletin No.: 11-00-90-001 Date: March 14, 2011 Subject: Global Information for GM dexos1(TM) and GM dexos2(TM) Engine Oil Specifications for Spark Ignited and Diesel Engines, Available Licensed Brands, and Service Fill for Adding or Complete Oil Change Models: 2012 and Prior GM Passenger Cars and Trucks Excluding All Vehicles Equipped with Duramax(TM) Diesel Engines GM dexos 1(TM) Information Center Website Refer to the following General Motors website for dexos 1(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 1(TM) Engine Oil Trademark and Icons The dexos(TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos‹›(TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos‹›(TM) specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 1(TM) engine oil. GM dexos 1(TM) Engine Oil Specification Important General Motors dexos 1(TM) engine oil specification replaces the previous General Motors specifications GM6094M, GM4718M and GM-LL-A-025 for most GM gasoline engines. The oil specified for use in GM passenger cars and trucks, PRIOR to the 2011 model year remains acceptable for those previous vehicles. However, dexos 1(TM) is backward compatible and can be used in those older vehicles. In North America, starting with the 2011 model year, GM introduced dexos 1(TM) certified engine oil as a factory fill and service fill for gasoline engines. The reasons for the new engine oil specification are as follows: - To meet environmental goals such as increasing fuel efficiency and reducing engine emissions. - To promote long engine life. - To minimize the number of engine oil changes in order to help meet the goal of lessening the industry's overall dependence on crude oil. dexos 1(TM) is a GM-developed engine oil specification that has been designed to provide the following benefits: - Further improve fuel economy, to meet future corporate average fuel economy (CAFE) requirements and fuel economy retention by allowing the oil to maintain its fuel economy benefits throughout the life of the oil. - More robust formulations for added engine protection and aeration performance. CPI - Fuel Leak May Cause Driveability Problems Fuel Supply Line: All Technical Service Bulletins CPI - Fuel Leak May Cause Driveability Problems Number: 93-99-6C Section: 6C Date: FEB. 1993 Corporate Bulletin No.: 266306 ASE No.: A1, A8 Subject: CENTER PORT FUEL INJECTION (CPI) LINE CLIPS INFORMATION Model and Year: 1992-93 S/T AND M/L TRUCKS WITH 4.3L ENGINE (RPO 135) Improper installation of the fuel line clips which hold the fuel inlet and outlet tubes to the Central Port Fuel Injection (CPI) unit may result in an internal CPI fuel leak. A fuel leak may cause driveability problems or in extreme cases, hydrolock. Proper Removal and Installation of Fuel Line Clips Removal: Using needle nose pliers, firmly grasp the fuel fitting clip as shown in Figure 1 and pull the clip straight back from the fuel meter body. It may be necessary to lift the opposite side of the clip with a screwdriver. Discard the clip. Installation: Always use a new clip and O-rings (P/N 17112702). Using your fingers as shown in Figure 2, slide the clip over the fuel meter body making sure that the clip properly engages the slots in the fuel inlet and outlet tubes and that the clip is properly positioned over the fuel meter body on both the top and bottom sides. The clip will be properly positioned when the flanges on the fuel meter body protrude from the clip and the clip snaps in place. IMPORTANT: Do not install the clip from the bottom-up position, the clip will not properly retain the fuel lines. Install the clip from the top-down position as shown in Figure 2. Secondly, it is important to note that the fuel lines MUST be in the correct inlet/outlet openings (The lines will fit either opening). Lastly, the fuel lines MUST be correctly seated into the TBI body to allow for proper installation of the clips. Parts Information: Part Number - 17112702 Description - Seal Kit Parts are currently available from GMSPO. Page 8352 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 8411 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 8351 Figure 7 Figure 8 Figure 9 Figure 10 Page 3488 voltage reading. TPS voltage at idle should be less than 1.0 volts (approximately 0.6 volts). With the engine off and the accelerator pedal depressed to wide open throttle, the TPS voltage should read about 4.6 volts for the 4.3L (LB4) engine. When the accelerator pedal is depressed and voltage readings are less than the previously mentioned voltage specifications, replace the pedal assembly with a redesigned pedal assembly (P/N 15679725). Important: Make sure during pedal assembly installation that the insulation mat does not get trapped between the pedal assembly and dash panel (Figure 1). Page 4835 The hydraulic pushrod operates against the master cylinder piston. A split system (tandem piston) type master cylinder is incorporated into some units. The front half of the master cylinder in the split system operates the rear brakes while the rear half of the master cylinder operates the front brakes. A vacuum check valve, attached to the front vacuum chamber and connected to the intake manifold, traps vacuum in the power unit at the highest level of vacuum. OPERATION As the brakes are applied by the driver, the valve operating rod and control piston move forward in the power piston assembly to compress the valve return spring and bring the poppet valve into contact with the vacuum valve seat in the valve housing to close the vacuum post. Any additional movement of the valve operating rod in the applied direction moves the control valve away from the poppet valve to open the atmospheric port and admit air through the air filter and passages to the chamber at the right of the vacuum power piston assembly. With vacuum on the left side of the diaphragm and atmospheric pressure on the right side of the diaphragm, a force is developed to move the vacuum power piston assembly, hydraulic pushrod, and hydraulic piston to the left to close the compensating port and force hydraulic fluid under pressure through the residual check valve and brake tubes into the brake wheel cylinders. Page 8175 Door Switch: Locations Door Jamb Switch, LH Rear In LH B-Pillar Interior - Itch Noise From Windshield Pillar Area Dashboard / Instrument Panel: All Technical Service Bulletins Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 426 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: All Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Page 4603 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 2531 Engine Wiring, LH Side Page 1339 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 43 Figure 7 Figure 8 Figure 9 Figure 10 Page 651 Oxygen Sensor: Description and Operation Exhaust Oxygen Sensor (02) PURPOSE The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315°C (600°F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Oxygen Sensor Output Voltage vs. Air/Fuel Ratio The difference in oxygen concentration in the narrow range of optimum air/fuel ratio causes a large voltage change that is easily measured. OPERATION A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. Page 6594 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 3992 Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Page 4880 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 61 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 2030 Engine Broadcast Code Information (last three digits of the engine I.D. number located In front of the right cylinder head at deck height): WARRANTY INFORMATION Condition I - For vehicles repaired by changing balance shaft drive gears: Condition II - For vehicles repaired by installing a Goodwrench engine: Important: Applicable miscellaneous items, such as engine oil and engine coolant, should be added to the above part allowance amount and included in the Net Amount (DMN) column of the claim. PARTS INFORMATION Content: Cylinder and case, cylinder head assembly, crankshaft, crankshaft main and rod bearings, piston and connecting rod assembly, T Truck/L Van oil pan and screen assembly, camshaft, valve lifters, push rods, camshaft chain and sprockets, balance shaft, balance shaft drive gears, valve lifter retainer, front cover and pointer, valve rocker cover, oil fill cap, harmonic balancer. Additional Parts Required to Dress-Out the Goodwrench Engine: (Quantity: 1 each, except as noted) Page 696 Vehicle Speed Sensor: Description and Operation 2 Wheel Drive (Manual Transmission) VSS 2WD Manual Transmission 2 Wheel Drive (Automatic Transmission) VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 4 Wheel Drive or All Wheel Drive VSS 4WD Or AWD PURPOSE The Vehicle Speed Sensor (VSS) provides information to the control module for control of: Transmission Torque Converter8Clutch (TCC) - Speedometer - Odometer Page 5962 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Page 5791 Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. Final Inspection 1. After remounting and inflating the tire, check both beads, the repair and the valve with a water and soap solution in order to detect leaks. 2. If the tire continues to lose air, the tire must be demounted and reinspected. 3. Balance the tire and wheel assembly. Refer to Tire and Wheel Assembly Balancing - OFF Vehicle. For additional tire puncture repair information, contact: Rubber Manufacturers Association (RMA) Disclaimer Page 1291 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 1603 Camshaft: Service and Repair Fig. 15 Timing Mark Alignment 1. Disconnect battery ground cable. 2. Remove air cleaner assembly and drain cooling system. 3. Remove rocker arm covers and pushrods as described under ROCKER ARM & PUSHRODS. 4. Remove distributor. 5. Remove intake manifold as described under INTAKE MANIFOLD. 6. Remove valve lifters as described under VALVE LIFTERS. 7. Remove radiator, fan and pulley. 8. Remove water pump and torsional damper. 9. Remove timing cover. 10. Remove camshaft sprocket bolts, then the sprocket and timing chain. 11. Remove thrust plate attaching bolts, then the thrust plate. 12. Remove camshaft. 13. Reverse procedure to install. Ensure timing marks are properly aligned after installation of sprockets and chain, Fig. 15. Page 5074 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 4628 Brake Bleeding: Technical Service Bulletins Brakes - Revised 4WAL System Bleeding Procedure BULLETIN NUMBER: 93-5E-74 SECTION: 5E Antilock Brakes NUMBER: 3 CORPORATE REFERENCE NUMBER: 365003 DATE: May 1993 SUBJECT: REVISED 4WAL BRAKE SYSTEM BLEEDING PROCEDURE (INFORMATIONAL) MODELS: 1990-93 MIL, S/T AND 1992-93 C/K AND 1993 G MODELS WITH 4WAL THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 91-5E-23, CORPORATE NUMBER 065001R, DATED SEPTEMBER 1990 TO UPDATE THE BLEED PROCEDURE AND TO ADD MODELS SINCE EQUIPPED WITH 4WAL BRAKE SYSTEMS. ALL COPIES OF 91-5E-23 SHOULD BE DISCARDED. THIS BULLETIN ALSO UPDATES INFORMATION IN 1993 MIL SERVICE MANUAL X9330, 1993 S/T SERVICE MANUAL X9329, 1993 C/K SERVICE MANUAL X9331, 1993 G SERVICE MANUAL X9357, AND STG RWAL/4WAL 1988-1991 APPLICATIONS MANUAL 15005.05 (VERSIONS 2 TO 5). PLEASE PLACE A COPY OF THIS BULLETIN IN EACH MANUAL. THIS BULLETIN IS EQUIVALENT TO SERVICE MANUAL UPDATE (CORP. NO. 263003). This 4WAL brake system bleed procedure is the most efficient bleed procedure to date. The 4WAL Brake Pressure Modulator Valve (BPMV), formerly called Electro Hydraulic Control Unit (EHCU), should be bled after replacement or if air is suspected to be trapped inside the unit. There are two conventional methods to use when bleeding the 4WAL BPMV: (1.) Pressure Bleeding or (2.) Manual Bleeding. Important There are two internal bleed screws (brass colored), one on each side of the BPMV, that open internal channels. Open the internal bleed screws 1/4 to 1/2 turn before bleeding (Figure 2). New 4WAL BPMV's are shipped with the internal bleed screws open, so first close the internal bleed screws until snug, then open 1/4 to 1/2 turn. Note: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid Adjustments Idle Speed Control Motor: Adjustments Base Idle Speed is not adjustable on this engine and is controlled by the control module. Refer to FUEL SUPPLY AND AIR INDUCTION/ADJUSTMENT PROCEDURES for adjusting Controlled Idle Speed. Page 1283 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 5270 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 7276 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Interior - Noise From Windshield Pillar Area Windshield: All Technical Service Bulletins Interior - Noise From Windshield Pillar Area BULLETIN NUMBER: 92-10-130 SECTION: 10 NUMBER: 1 CORPORATE REFERENCE NUMBER: 261610 DATE: September 1992 SUBJECT: NOISE FROM WINDSHIELD PILLAR AREA (DIAGNOSE/INSTALL FELT TAPE) MODELS: 1986-92 S1/T1 UTILITY TRUCKS Some 1986-92 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm mil to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE Prior to installing the felt tape, it should be determined IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in fmnt of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screw drivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. SERVICE PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, see chart. Page 7176 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 4955 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 5064 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 4560 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Body - Polypropylene Energy Absorber Replacement Rear Bumper Reinforcement: Technical Service Bulletins Body - Polypropylene Energy Absorber Replacement Bulletin No.: 07-08-63-001 Date: April 17, 2007 INFORMATION Subject: Information on Repair of Polypropylene Energy Absorbers Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to change the repair information. Please discard Corporate Bulletin Number 63-20-02 (Section 8 - Body and Accessories). Because the energy absorbers are relatively low in cost to replace, it is now more cost efficient to replace the energy absorbers whenever they are damaged. Disclaimer Page 6639 Symbol Identification Page 74 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 2619 Electronic Spark Control (ESC) Circuit Circuit Description: The Code 43 circuit consists of two knock sensors with one wire that goes directly to the ECM. There are two Code 43 checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 4.4 volts. If voltage is either too high or too low for 2 or more seconds, Code 43 will set. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3800 rpm, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, Code 43 will set. Diagnostic Aids: The ECM applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the ECM, is able to read this signal as knock and incrementally retard spark. If the ESC system checks OK, but detonation is the complaint, See: Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Page 5856 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Page 7385 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 7401 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 5788 1. Use a proper hand reamer, carbide cutter or drill bit to ream the puncture channel from the inside of the tire in order to clean the injury. 2. Remove steel wires protruding above the liner surface to prevent damage to the repair unit. 3. Consult your repair material supplier for recommended reaming tool(s). Fill the Injury 1. It is necessary to fill the injury channel to provide back up for the repair unit and to prevent moisture from entering the tire fabric and steel wires. 2. (For combination repair/plug units skip this step.) Cement the injured channel and fill the injury from the inside of the tire with the repair plug per repair material manufacturer's recommendations. Without stretching the plug, cut the plug off just above the inside tire surface. 3. Consult your repair material supplier for proper repair material selection. Repair Unit Selection Important Do not install the repair unit in this step. Page 5257 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 4348 Rear Drive Axle Troubleshooting Page 8539 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 1700 Crankshaft: Specifications Crankshaft Journals Crankshaft Journals Main Bearing Journal Diameter Front 2.4484-2.4493 in Intermediate 2.4481-2.4490 in Rear 2.4479-2.4488 in Connecting Rod Journal Diameter 2.2487-2.2497 in Maximum Out Of Round All 0.001 in Maximum Taper All 0.001 in Runout Service Limit Note: If main journals are misaligned, crankshaft is bent & should be replaced. Page 7778 8. Remove ashtray and any wires needed for clearance to remove radio trim plate. 9. Remove radio trim plate, then the nuts from the support clips, Fig. 25. 10. Remove support bracket retaining screws, then pull radio rearward and disconnect electrical connectors, antenna cable and speaker connectors. 11. Remove speaker grille attaching screws, then the speakers, Fig. 26. 12. Remove instrument panel attaching bolts and nuts, then pull panel rearward, disconnect all electrical connectors and remove panel. 13. Reverse procedure to install. Page 3762 PROM - Programmable Read Only Memory: Service and Repair EEPROM CAUTION: The Erasable Programmable Read Only Memory (EEPROM) is a permanent memory that is physically soldered to the circuit boards within the computer. It is not serviceable and should not be removed for replacement. If COMPUTER replacement is performed, reprogramming of the EEPROM will be necessary. Failure to do this will cause the vehicle to have a no start or poor running condition. Reprogramming of the EEPROM is only possible with the Service Stall System (SSS) hardware available at authorized dealer locations. Check with a dealer before performing COMPUTER replacement or EEPROM reprogramming. Page 4355 Axle Shaft Assembly: Service and Repair Chevrolet Salisbury Type Semi-Floating Axle Shaft, Replace REAR AXLE SHAFT Fig. 3 Removing differential pinion shaft 1. Raise vehicle and remove wheel and brake drum. 2. Drain lube from carrier and remove cover. 3. Remove differential pinion shaft lock screw and remove differential pinion shaft, Fig. 3. 4. Pull flanged end of axle shaft toward center of vehicle and remove C-lock from button end of shaft. 5. Remove axle shaft from housing, being careful not to damage seal. 6. Reverse foregoing procedure to install the axle shaft. Axle Assembly REAR AXLE ASSEMBLY 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Housing REAR AXLE HOUSING Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and place jackstands under frame side rails. Support axle housing with a suitable jack. 2. Drain lubricant from axle housing and remove propeller shaft. 3. Remove wheel and brake drum. 4. Disconnect parking brake cable from lever and at brake flange plate. 5. Disconnect hydraulic brake lines from connector and lower shock mounting from axle brackets. 6. Remove vent hose from axle vent fitting if equipped. 7. Disconnect height-sensing and brake proportioning valve linkage if equipped. 8. Support assembly with a hydraulic jack and remove rear stabilizer bar. 9. Remove U-bolts, spring plates and spacers from axle assembly. Page 7349 Symbol Identification Page 4934 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 3866 Removal Wheel Cylinder: Service and Repair Removal For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove drum. 4. Remove brake shoes. 5. Disconnect hydraulic line at wheel cylinder. CAUTION: Do not pull metal line away from cylinder, as this may kink or bend line. Line will separate from cylinder when cylinder is moved away from brake backing plate. 6. Remove wheel cylinder-to-brake plate attaching screws, then the wheel cylinder. Page 1235 Brake Bleeding: Technical Service Bulletins Brake Pressure Modulator Valve - Bleed Procedure Number: 93-12-5 Section: 5 Date: SEPT. 1992 Corporate Bulletin No.: 263003R ASE No: A5 Subject: REVISED BRAKE PRESSURE MODULATOR VALVE (BPMV) BLEED PROCEDURE Model and Year: 1990-93 LIGHT DUTY TRUCKS WITH 4WAL SERVICE UPDATE The brake pressure modulator valve (BPMV) (formerly called the EHCU) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves (item A, figure 1) 1/4 to 1/2 turn before bleeding. Should the BPMV need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTE: The ignition switch must be in the "OFF" position or false diagnostic trouble codes could be set to memory. Tools Required: J 39177 Combination Valve Pressure Bleeding Tool (Three Required) TK 00000 Tech-1 Scan Tool TK 02650 RWAU4WAL Cartridge Kit IMPORTANT You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV (figure 1). 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV (figure 1). Page 4484 Torque Converter Clutch Solenoid: Locations Torque Converter Clutch Solenoid (TCC) Inside automatic transmission attached to valve body. Page 1027 EGR Filter: Service and Repair EVRV Filter Replacement EVRV Filter Replacment REMOVAL AND INSTALLATION: 1. Grasp and pull the filter OFF with a rocking motion. 2. Push the new filter on making sure that the cut-out for the wires is properly aligned. Page 8543 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Locations Horn Relay Installation A/C - R12 or R134a Service Recommendations Technical Service Bulletin # 631209 Date: 960501 A/C - R12 or R134a Service Recommendations File In Section: 1 - HVAC Bulletin No.: 63-12-09 Date: May, 1996 INFORMATION Subject: Service Issues for Vehicles with R12 or R134a Air Conditioning Systems Models: 1988-96 Passenger Cars and Trucks R12 Service Recommendations As you know, production of R12 refrigerant ceased on December 31, 1995. Although R12 will no longer be manufactured, there is a reserve supply of R12 available. This reserve, along with strict A/C repair service adherence to proper refrigerant recycling procedures, should assure continued availability to meet consumers' needs. R12 can and should continue to be used to service vehicles built with R12 A/C systems as long as it is available. If R12 is no longer available or affordable, a system retrofit utilizing R134a is recommended. R134a IS THE ONLY SUBSTITUTE REFRIGERANT RECOMMENDED BY GM FOR USE IN GM VEHICLE A/C SYSTEMS, AND THEN ONLY AFTER FOLLOWING THE PROPER RETROFIT PROCEDURES FOR THE SPECIFIC MODEL. All new vehicle manufacturers have chosen R134a for retrofit. One of the key reasons is to protect both the service industry and consumers from the high costs that would result from purchasing equipment necessary to service multiple refrigerants. This position also reduces the threat of recycled refrigerant contamination. GM currently offers a simple, low cost R12 to R134a retrofit on many of its late model, front wheel drive passenger cars. Dealers should discuss this capability with owners of these specific models, listed in Retrofit Corporate Bulletin # 43-12-07D, whenever a repair to the A/C refrigerant system is required. Early retrofit of these specific models will aid in prolonging availability of the R12 supply and provide dealer service technicians the opportunity to become more familiar with the proper procedures for performing a retrofit. Remember - R12 and R134a refrigerant are not interchangeable! They cannot be mixed together. In fact, despite the claims of some refrigerant manufacturers, no proposed R12 refrigerant substitute can be added to, mixed with or used to "top off" an R12 system. Under provisions of law covering the service of refrigerants, mixing dissimilar refrigerant products during service is prohibited. To Summarize GM R12 Service Policy 1. Service R12 vehicles with good quality new or recycled R12 as long as it is available. 2. Purchase R12 from a reliable supplier. GMSPO has a supply of high quality R12 available. Dealers are requested to use only R12 supplied by GMSPO for warranty repairs. This high quality refrigerant will insure system performance and avoid the possibility of introducing contaminated material into the customer's A/C system. 3. Carefully test recovered R12 using the PureGuard monitor. On recovery equipment not protected by the PureGuard, always test the recovery cylinder prior to recharging a vehicle A/C system. 4. Discuss the R12 to R134a retrofit option with owners of GM vehicles listed in Retrofit Corporate Bulletin # 43-12-07D. Provide owner with a copy of the pamphlet "Converting Your Auto Air Conditioning System to Use the New Refrigerant". 5. Become familiar with retrofit procedures and exercise care in the handling of dissimilar refrigerants to prevent contamination. R134A Service Recommendations When servicing a previously retrofitted vehicle, there is concern that if all of the R12 is not completely removed prior to the retrofit procedure, it could contaminate your R134a equipment and recovery tank when a subsequent A/C repair is performed. Although the number of retrofits being performed today is minimal, the volume will increase as R12 prices rise. GM Service Technology Group is in the process of field testing a new R134a refrigerant purity tester similar to the PureGuard R12 refrigerant tester you now use. This new tool will mount to your ACR4 R134a Recovery Recycle and Recharge cart and sample all R134a refrigerant prior to recovery. It is expected that testing of this tool will be completed this year. This new tool, the Pureguard 2, will also test vehicles and your recycle tank for air contamination, which is threatening A/C system performance. High levels of air have been found in the recovery tanks on a number of R12 and R134a recovery carts. Air contamination is caused by improper recovery Page 5356 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Page 5643 (See Figure 2) Procedure 1. Place J 42882 over the end of the stub shaft. Place J 43435 over the end. J 43435 is reversible and can be used with both old and new style coupling shield retainers and locknuts. 2. Tighten the coupling shield retainer and locknut assembly after an adjustment or repair has been made to the power steering gear to the specified torque (See Figure 3). Diagram Information and Instructions Antilock Brake Module: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Fuel - Removal And Installation of CPI Fuel Line Clips Fuel Return Line: Technical Service Bulletins Fuel - Removal And Installation of CPI Fuel Line Clips BULLETIN NO: 93-6C-46 SECTION: 6C NUMBER: 3 CORPORATE REFERENCE NO: 266306 DATE: February, 1993 SUBJECT: INFORMATION ON INSTALLATION OF CPI FUEL LINE CLIPS MODELS: 1992-93 S/T AND M/L MODELS WITH 4.3L ENGINES (RPO L35) Improper installation of the fuel line clips which hold the fuel inlet and outlet tubes to the Central Port Fuel Injection (CPI) unit may result in an internal CPI fuel leak. A fuel leak may cause driveability problems or in extreme cases, hydrolock. Proper Removal and Installation of Fuel Line Clips: Removal Using needle nose pliers, firmly grasp the fuel fitting clip as shown in Figure 1 and pull the clip straight back from the fuel meter body. It may be necessary to lift the opposite side of the clip with a screwdriver. Discard the clip. Installation Always use a new clip and 0-rings (P/N 17112702). Using your fingers as shown in Figure 2, slide the clip over the fuel meter body making sure that the clip properly engages the slots in the fuel inlet and outlet tubes and that the clip is properly positioned over the fuel meter body on both the top and bottom sides. The clip will be properly positioned when the flanges on the fuel meter body protrude from the clip and the clip snaps in place. Important Do not install the clip from the bottom-up position, the clip will not properly retain the fuel lines. Install the clip from the top-down position as shown in Figure 2. Secondly, it is important to note that the fuel lines MUST be in the correct inlet/outlet openings (The lines will fit either opening). Lastly, the fuel lines MUST be correctly seated into the TB body to allow for proper installation of the clips. Page 4989 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: Customer Interest Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. P/S - Reduced Assist When Cold Power Steering Fluid: All Technical Service Bulletins P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Door Locks - Binding or Sticking or Key Hard to Insert Door Lock Cylinder: Customer Interest Door Locks - Binding or Sticking or Key Hard to Insert Number: 93-133-10 Section: 10 Date: MARCH 1993 Corporate Bulletin No.: 1341070R ASE No.: B1 Subject: DOOR LOCK CYLINDERS (RECOMMENDED LUBRICATION) Model and Year: ALL 1993 AND PREVIOUS MODEL CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN 92-41-10, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS A NOTE. PLEASE DISCARD ALL COPIES OF 92-41-10. Customer comments of binding/sticking door lock cylinders, or keys that are hard to insert or extract may be corrected in many cases by applying the proper lubrication. The recommended materials for lubricating these components are (in order of preference): - GM # 12345120 Multi purpose lubricant (9 oz. spray) or # 12345121 (12 oz.). - 5 W 30 Motor Oil - GM # 1052276 or 1052277 spray type Silicone (4.5 oz. or 12 oz. cans). Penetrating oil type lubricants (such as GM # 1052949 or 1052950, WD-40 lubricants) ARE NOT RECOMMENDED because they wash out the original lubrication and eventually evaporate, leaving little or no lubricating material. However, if these type materials are used to "unfreeze" or loosen lock cylinder components, refer to steps 2 through 4 listed below for the proper methods of lubricating. NOTE: DO NOT REPLACE THE DOOR LOCK CYLINDERS UNTIL AFTER THE LUBRICATING MATERIALS HAVE BEEN USED AND THE CYLINDER REMAINS FROZEN/BOUND. If door lock cylinders require replacement for any reason, apply a coating of GM # 12345120 Multi purpose Lubricant to the inside of the lock case and the cylinder keyway prior to assembling and installing the cylinder. Parts are currently available from GMSPO. Frozen cylinders due to cold weather may be repaired using the following procedure: 1. Apply heat to the cylinder area with a heat gun while being careful not to damage the painted surfaces. 2. Hold the shutter door open with a paper clip (or similar item) and force air into the cylinder using compressed air and a blow gun attachment. 3. While holding the shutter door open, inject a small amount of lubricant (see above recommendations) into the cylinder. 4. Work the key into the cylinder several times and wipe any excess lubrication residue from the key. Use applicable Labor Time Number and Time allowance. Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 1075 Coolant: Technical Service Bulletins Warranty - Recycled Engine Coolant Policy Group Ref.: Warranty Administration Bulletin No.: 310504 Date: February, 1994 WARRANTY ADMINISTRATION SUBJECT: RECYCLED ENGINE COOLANT POLICY MODELS: 1994 AND PRIOR PASSENGER CARS AND TRUCKS ATTENTION: WARRANTY CLAIMS ADMINISTRATOR AND SERVICE MANAGER General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. For detailed information on GM approved engine coolant recycling equipment guidelines refer to the following bulletins: Cadillac 93-1-18, GMC Truck 93-6B-34, Chevrolet 93-73-6B, Pontiac 93-6-18, Oldsmobile 1-93-43, Buick 93-6B-1 (Corporate Number 236203). Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial to assure that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words, if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Page 1154 thread locking compound, such as Loctite(R) 242, should be used on each bolt of the saddle clamp to prevent the threads from loosening. Some vehicles produced during the second half of the 1993 model year will already have a factory installed HPCOS. Check the back of the compressor for this switch. If present, the above switch will not have to be added. 5. Evacuate the System, and Recharge with PAG or V5 Retrofit Oil and R-134a Newly designed low profile quick connect couplers for the ACR4, J 39500-20A and J 39500-24A, have been released. These should be installed before proceeding with the evacuation. See Step 3, and Figure 3. a. Connect the R-134a cart (ACR4) to the system. Open the coupler valves on the hoses so that the pressures can be read on the gauges. On the cart, open the HIGH SIDE VALVE ONLY. DO NOT OPEN THE LOW SIDE VALVE! Program the cart for a 15 minute evacuation. Important: If the vehicle has been at outside temperatures of less than 50° F (10° C), or at high altitudes (above 3000 ft), use a 30 minute evacuation to insure complete removal of the R-12. If the vacuum pump will not start and a "H-P" reading is indicated on the ACR4 display, loosen the fitting at the high side line connection to the ACR4 to relieve pressure in the line. Tighten the fitting after pressure has been relieved. DO NOT USE THE RECOVERY MODE TO RELIEVE LINE PRESSURE. b. Start the evacuation. For a proper evacuation, the cart must pull down to 28-29 in. Hg. at sea level (reduce by 1 in. for each 1000 ft above sea level). Check the low side gauge for proper vacuum level, to make sure the new fittings are operating properly. While the evacuation is being done, the Retrofit label can be filled out and installed (see Step 6). Important: If the compressor was replaced at the same time as this retrofit, and the new compressor was shipped with the correct amount of PAG oil already in it, DO NOT add any additional oil to the system! Go to Step D. If an "oil-less" compressor was installed, add oil in Step C. A new retrofit oil for use with V5 compressor vehicles has been released. This oil will be used ONLY for retrofitted vehicles in which the original V5 compressor is retained. IT WILL NOT BE USED IF A COMPRESSOR IS REPLACED AT THE TIME OF THE RETROFIT. Failure to use this oil may significantly shorten the useful life of the compressor. Important: If the V5 Retrofit oil is not available from GMSPO, the compressor MUST BE REPLACED! To summarize the correct retrofit oil usage: ^ Compressor replaced during retrofit - NO OIL ADDED if new compressor shipped with oil - 8 oz. of PAG oil (9 oz of PAG oil with V5 compressor) added if compressor shipped without oil ("oil-less" design) Specifications Intake Air Temperature Sensor: Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Page 4951 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Paint - Codes & Cross References Paint: All Technical Service Bulletins Paint - Codes & Cross References GMC NUMBER: 92-10-05 GROUP: 10 Body Section DATE: August, 1991 CORPORATE NUMBER: 161702R SUBJECT: 1992 PAINT CODES, ASSEMBLY PLANT IDENTIFICATION AND PAINT SUPPLIERS MODELS: ALL 1992 TRUCKS 1992 ASSEMBLY PLANT PAINT IDENTIFICATION Attached is a current listing of the various assembly plants and their paint suppliers. It should be noted, however, that paint suppliers are subject to change at any given time. Paint Type Assembly Plant Plant Paint (Trucks) Code Supplier Basecoat/Clear- Baltimore, MD B PPG coat Enamel (M/L) High Solids Janesville, WI J Dupont Enamel (MD) High Solids Lordstown, OH 7 BASF Enamel (G) High Solids Moraine, OH 2 Dupont Enamel (S/T) Basecoat/Clear- Oshawa Truck 1 ICI coat Waterborne Plant (C/K) High Solids Pontiac-West, 0 BASF Enamel MI (S/T) Basecoat/Clear- Pontiac-East, MI E Dupont coat Enamel (C/K) Medium Solids Scarborough, 4 ICI Enamel Ontario (G) High Solids Shreveport, LA 8 BASF Enamel (S/T) Basecoat/Clear- Ft. Wayne, IN Z Dupont coat Enamel (C/K) Basecoat/Clear- Janesville, WI J PPG coat Enamel (C/K-Suburban, Yukon, Sierra Crew Cab) The following is a list of paint code numbers from various suppliers for the 1992 model year. These colors can be obtained locally. BASF refinished paints are available in: A - Alphacryl(R) D - Diamont 88(R) SO - Diamont Solo(R) 21 - Glasurit-21(R) 54 - Glasurit-54(R) S - Limco Select(R) L - Limco Supreme Gold(R) Page 6678 Figure 7 Figure 8 Figure 9 Figure 10 Engine - Cold Knock PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine - Cold Knock Number: 93-155A-6A Section: 6A Date: AUGUST 1993 Corporate Bulletin No.: 376105R ASE No.: A1, A8 Subject: COLD ENGINE KNOCK Model and Year: 1991-93 C/K, R/V, M/L, S/T, G TRUCKS WITH 4.3L, 5.7L AND 7.4L ENGINES THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 93-155-6A DATED MARCH 1993. THE CORRECTION SECTION HAS BEEN CHANGED COMPLETELY. COPIES OF 93-155-6A SHOULD BE DISCARDED. CONDITION: Some late model LB4 (VIN Z 4.3L V6), L05 (VIN K 5.7L V8), and L19 (VIN N 7.4L V8) truck engines have been reported to exhibit "cold knock" on start up. "Cold knock" usually occurs after the vehicle has been completely warmed, then parked for 8 or more hours in ambient temperatures of 35 degrees Fahrenheit or less. "Cold knock" can be separated into three distinct categories. A. Short Duration - Harsh deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. B. Valve Train - Light clatter, tick or click that may last up to 1 minute. C. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. CORRECTION - CATEGORY A: Short Duration Knock For 1992 LB4 4.3L VIN Z ONLY: Install PF52 oil filter. Install a revised PROM that reduces the engine spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROM will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROMs contain the previously released calibration update for torque converter clutch (TCC) lock-up (see Dealer Service Bulletin No. 92-75-7A) if the vehicle has an automatic transmission or neutral gear rattle if the vehicle has a manual transmission (see Dealer Service Bulletin No. 92-187A-7B). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Dealer Service Bulletin No. 92-285B-6E for more information on detonation. NOTE: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. SPO will be temporarily stocking four (4) PROMs for each light duty 1992 model year LB4 application. Base Detonation Fix Cold Knock Fix Combination Cold Knock and Detonation Fix The detonation fix (detonation fix only) PROMs will not be restocked by SPO when the current supply is exhausted. If a detonation fix PROM is required after the existing stock is exhausted, the combination cold knock and detonation PROM is to be used. Special Parts Assistance Center will have information available on each PROM. Select the PROM from the table. Old broadcast code (OLDB/C Code) information has been supplied to help determine if a detonation fix PROM has been installed previously. If the Old B/C Code can be found in the first table, a detonation fix has not been installed. If the broadcast code cannot be found in the tables, call the appropriate marketing division technical assistance group. PROMs are expected to be available from GMSPO August 30, 1993. Intake Air Temperature (IAT) Sensor Intake Air Temperature (IAT) Sensor 4.3W Page 3990 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 1167 accumulator. The system will operate properly as long as refrigerant charge amounts are strictly adhered to. 6. Refrigerant Charge Level The retrofit R-134a charge level is more critical than with R-12 systems. Overcharging may push the mineral oil out of the AID, and cause it to circulate as a liquid. This is more likely to result in compressor damage. Undercharging may lead to loss of performance. It is very important to clear the hoses during the charging operation, to insure that all the refrigerant is delivered to the vehicle A/C system. This is covered in Step 6D of the Retrofit Procedure. C. Parts Information Page 1862 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 3391 Locations Daytime Running Lamps, I/P Wiring Page 8671 Window Regulator: Service and Repair Without Power Windows Door Armrest Replacement Front Door Trim Panel REMOVE OR DISCONNECT 1. Screws securing the armrest to the door trim. 2. Armrest from the door trim. ^ Slide the armrest towards the rear of the door, and then, lift the armrest from the door. INSTALL OR CONNECT 1. Armrest to the door trim. ^ Place the armrest retaining clips in the slots on the door panel. ^ Slide the armrest toward the front of the door unit the holes in the armrest align with the holes in the door trim. 2. Screws securing the armrest to the door trim. Door Inner Panel Water Deflector Replacement Page 2210 Fan Blade: Service and Repair To prevent silicone fluid from draining into fan drive bearing, do not store or place drive unit on bench with rear of shaft pointing downward. The coil spring type fan clutch cannot be disassembled, serviced or repaired. If it does not function properly, it must be replaced with a new unit. To replace the fan clutch, use the following procedure: 1. Remove the radiator fan shroud. 2. Unfasten the unit from the water pump, then remove the assembly from vehicle. 3. Separate fan from fan clutch. 4. Reverse procedure to install, noting the following: a. Ensure mating surfaces of water pump hub and fan clutch hub are smooth and free of any burrs. b. Align yellow reference marks on water pump hub and fan clutch hub. c. Torque nuts to 18 ft. lbs. Page 7723 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 4710 NOTE: Carefully note the color of the spring and which hole it came out of. Liquid typewriting eraser or nail polish can be very useful in marking the appropriate hole for later installation. Installation Install the spring into the brake shoe webbing first. The two 90 degree bends should slide into the hole and lie flat, locking the spring to the webbing. - Slide the brake spring tool through the looped end of the spring and then hook the notched end of the tool over the anchor pin. - Pivot the tool upwards to stretch the spring over the anchor pin (a light film of grease on the backside of the brake tool will help the spring slide over and onto the anchor pin). - Be careful not to over-extend the spring. WARNING: Do not attempt to help the spring over the anchor pin with your fingers. Should the return spring slip off the tool it could seriously lacerate your hand. Shoe-to-Shoe Return Springs Removal Note the color and relationship of the spring and the holes in the brake shoe webbing it is attached to. - Using a pair of brake spring pliers, slide the hooked end of the pliers around and under one end of the spring. Page 5229 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 1559 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Page 5463 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 5070 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Locations Turn And Hazard Lamp Flashers Locations Daytime Running Lamps, I/P Wiring Page 528 Fuel Pump And Sender Assembly (Typical) Page 1741 Rocker Arm Assembly: Service and Repair Rocker Arms & Pushrods Replace 1. Disconnect battery ground cable. 2. Remove air cleaner assembly, then the emission relays and bracket. 3. Remove wiring harnesses and spark plug wires from clips and position aside. 4. Disconnect dipstick tube from cylinder head and position tube aside. 5. Remove rocker arm cover. 6. Remove rocker arm nut, then rocker arm and ball. 7. Remove pushrod. 8. Reverse procedure to install. Adjust valves as described under ADJUSTMENT PROCEDURES/VALVES. Page 8587 Vanity Lamp: Component Tests and General Diagnostics Rearview Mirror Map Light Does Not Operate Vanity Mirror Does Not Light Page 3613 Knock Sensor: Description and Operation Electronic Spark Control Circuit Knock Sensor (KS) Sensor PURPOSE Varying octane levels in today's gasoline can cause detonation (also known as spark knock) in an engine. The Knock Sensor (KS) system has various knock sensors that are used on all engines except the 2.5L. The KS system reduces spark knock (detonation) in the engine. This allows the engine to have a maximum spark advance for improved driveablity and fuel economy. CONSTRUCTION This KS system has three main components: - KS Module. - Knock sensor - ECM OPERATION The knock sensor detects abnormal vibration (spark knocking) in the engine. The knock sensor is mounted in the engine block near the cylinders. The KS module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the Ignition Control (IC) to reduce spark knocking. The KS module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the knock sensor. This allows the ECM to maintain maximum timing advance under various engine load conditions. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards IC to reduce spark knock. Bleeding Electronic Hydraulic Control Unit (EHCU) Module Hydraulic Assembly: Service and Repair Bleeding Electronic Hydraulic Control Unit (EHCU) Module Fig. 59 EHCU/BPMV Module Bleeding The EHCU Module should be bled after replacement or if trapped air is in the unit. If bleeding is required the module must be bled thoroughly before the wheel cylinders and calipers. There are two bleeders on top of the unit that appear to be normal bleeders, Fig. 59. These are modulator bleeders and must remain closed when the unit is not pressurized. The internal bleeders are on either side of EHCU module. The valves are used to open the internal passages within the EHCU module. Both bleed valves must be rotated 1/4 to 1/2 a turn counterclockwise before beginning the bleed process. The valve on the lefthand side is used for the rear brakes and the valve on the righthand side is used for the front brakes. The ignition switch must be in the ``Off'' position or false trouble codes may be stored. 1. Install combination valve depressor tool No. J 35836 or equivalent to LH high pressure accumulator bleed stem of EHCU module. 2. Install combination valve depressor tool No. J 35836 or equivalent to RH high pressure accumulator bleed stem of EHCU module. 3. Install combination valve depressor tool No. J 35836 or equivalent to rear combination valve. 4. Ensure master cylinder fluid level, fill if required. 5. Bleed EHCU module as follows: a. Slowly depress brake pedal one time and hold. b. Open left modulator bleeder, until fluid flows clearly or pedal is depressed, the close left bleeder. c. Slowly release brake pedal. d. Wait 15 seconds, then repeat a through d until all air is bled from EHCU module. e. Close LH internal bleed valve. Torque bleed valve to 60 inch lbs. f. Repeat steps b through e for RH bleed procedure. g. Remove three tool Nos. J 35856 or equivalents. 6. Ensure master cylinder fluid level, fill if required. 7. Bleed wheel cylinder and calipers. 8. Turn ignition key to ``On'' position, then perform 3 function test with TECH1 scanner. 9. Check brake pedal feel and braking performance, repeat procedure if required. Locations Engine Coolant Temperature (ECT) W A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Locations Fog Lamp Switch And Relay Wiring Page 5496 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Page 8519 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 7245 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts A/T - 1-2 Accumulator Piston/Outer Spring Replacement Accumulator: All Technical Service Bulletins A/T - 1-2 Accumulator Piston/Outer Spring Replacement File In Section: 7 - Transmission Bulletin No.: 87-71-74 Date: November, 1998 INFORMATION Subject: 1-2 Accumulator Piston and Outer Spring Replacement Models: 1982-96 Buick Roadmaster 1982-96 Cadillac Brougham, Fleetwood, DeVille 1982-86 Chevrolet Caprice 1982-99 Chevrolet Camaro, Corvette 1982-99 Pontiac Firebird with HYDRA-MATIC 4L60, 4L60-E Transmission (RPOs MD8, M30) 1982-99 Chevrolet and GMC C/K, M/L, S/T, G Models 1991-99 Oldsmobile Bravada with HYDRA-MATIC 4L60, 4L60-E Transmission (RPOs MD8, M30) Transmissions built from 1982 through 1999 were built with one of two styles of 1-2 accumulator pistons and outer springs. Important: The 1-2 accumulator pistons and outer springs are not interchangeable. For replacement of the 1-2 accumulator piston and outer spring, remove the 1-2 accumulator assembly and inspect the interior for the presence of either an aluminum or composite (plastic) 1-2 accumulator piston. Design 1 1-2 accumulator assemblies with an aluminum piston and a round wire outer spring, use service package P/N 24204495 (1982-1993) or P/N 24204496 Page 7254 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Warranty - Guidelines for Claiming Windshield Replace Windshield: All Technical Service Bulletins Warranty - Guidelines for Claiming Windshield Replace File In Section: Warranty Administration Bulletin No.: 72-05-04 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Claiming C0034 - Windshield Replacement Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide retail and wholesale service personnel with guidelines for using the above subject labor operations. In an effort to understand the windshield replacements, the following two phase approval process is being implemented. We feel this approach will allow GM to be responsive to repair decisions on vehicles over 10,000 miles (16,000KMS), while providing you, our dealers, the empowerment to address customer needs on those cases requiring repairs early in the vehicle's life, under 10,000 miles (16,000KMS). Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Windshield replacement on vehicles under 10,000 miles (16,0OOKMS) can only be made after Service Management inspection, review and approval. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. ^ Windshield replacement on vehicles over 10,000 miles (16,000KMS) can only be made after Service Management inspection, review and approval from the divisional service representative. Vehicles may be required to be held for wholesale inspection. This approval must be noted on the repair order clearly identifying the defect and reason for replacement. This comment must be submitted in the comment field of the claim for engineering review. The claim will require wholesale authorization for payment. Additional Requirements ^ Windshields replaced must be held for the normal parts retention period and the defect should be clearly identified on the glass by means of tape and/or a grease pencil. ^ Sublet windshield replacements, like other sublet repairs are to be claimed for actual dealership cost less any discounts and or allowances offered. Sublet repairs cannot exceed the normal allowance provided to the dealership had the repair been completed in-house. See your GM Policy and Procedure Manual for the complete guidelines. Windshields damaged by normal wear, road hazards, vandalism, or other physical damage are not eligible for warranty coverage. Page 2818 idle air flow (IAC/passage + PCV + throttle valve + vacuum leaks). - Controlled idle speed is always specified for normal operating conditions. Normal operating condition is engine coolant temperature in operating range, the A/C is "OFF," manual transmission is in neutral or automatic transmission in drive with proper Park/Neutral Position (PNP) switch adjustment. A high or low engine coolant temperature, or A/C clutch engagement may signal the control module to change the IAC counts. - The minimum idle speed is set at the factory with a stop screw. This setting allows enough air flow by the throttle valves to cause the IAC valve pintle to be positioned a calibrated number of steps (counts) from the seat during normal controlled idle operation. The IAC counts will be higher than normal on an engine with less than 500 miles, or an engine operating at high altitude or an engine with an accessory load such as the alternator, A/C, power steering or hydra-boost brakes activated. Results of Incorrect Operation If the pintle is stuck open, the idle speed will remain high. If the pintle is stuck closed, the idle speed will be too low, and stalling may occur. If the pintle is stuck partially open, the idle speed will be higher than normal, and there will be no response to changes in engine load such as A/C ("ON") or transmission in ("Drive"). Page 7973 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Page 306 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Service and Repair Fuel Pressure Release: Service and Repair Fuel Supply System CMFI FUEL PRESSURE RELEASE PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure - Connect fuel pressure gauge to fuel pressure connection tap. Wrap a shop towel around fitting while connecting gauge to avoid spillage. - Install bleed hose into an approved container and open valve to bleed system pressure. Fuel connections are now safe for servicing. - Drain any fuel remaining in gauge into an approved container. Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Page 1293 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 8154 I/P Compartment Box Lamp Does Not Operate Page 5220 Relay Box: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 4973 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 41 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Automatic Transmission Neutral Safety Switch: Service and Repair Automatic Transmission 1. Remove battery ground cable. 2. Remove lower insulator panel. 3. Remove neutral start switch electrical connector. 4. Remove neutral start switch. 5. Reverse procedure to install, noting the following: a. Align actuator on the switch with holes in shift tube. b. Press down on front of switch until tangs snap into rectangular holes in the steering column jacket. c. Adjust switch by moving the gear selector to park. Page 4843 Fig. 8 Exploded View Of Delco-Moraine Tandem Diaphragm Brake Booster Components 1. Remove boot, silencer, vacuum check valve, grommet and front housing seal Fig. 8. 2. Scribe a line across front and rear housing, then install brake booster to brake mounting fixture tool No. J 23456 or equivalent, Fig. 4. 3. Turn fixture handle to unlock housings. 4. Remove return spring, power piston assembly and power piston bearing from rear housing, Fig. 8. 5. Remove piston rod, reaction retainer and power head silencer, Fig. 8. 6. Remove power piston and pushrod assembly as follows: a. While holding the pushrod down against a hard surface, grasp outside edge of diaphragm support and diaphragm, Fig. 8. b. Use a slight force to dislodge diaphragm retainer, Fig. 8. 7. Remove primary diaphragm and primary support plate from housing divider, Fig. 8. 8. Remove primary diaphragm from primary support plate, Fig. 8. 9. Remove secondary diaphragm and secondary support plate from housing divider, Fig. 8. 10. Remove secondary piston bearing from housing divider, Fig. 8. 11. Remove secondary diaphragm from secondary support plate, Fig. 8. 12. Remove reaction body retainer, reaction body, reaction disc and reaction piston from reaction body, Fig. 8. 13. Remove air valve spring and reaction bumper from end of air valve pushrod, Fig. 8. 14. Remove retaining ring from air valve pushrod assembly. 15. Remove air valve pushrod assembly by inserting a screwdriver through the pushrod eyelet and pulling pushrod assembly straight out. 16. Remove filter, retainer and O-ring from air valve pushrod assembly. 17. Inspect all parts for corrosion, nicks, cracks, cuts, scoring, distortion or excessive wear. Replace as necessary. 18. Clean all parts in denatured alcohol and dry with clean compressed air. Do not immerse power piston and pushrod assembly in alcohol. Assembly 1. Install lubricated O-ring onto air valve pushrod assembly. 2. Install air valve pushrod into the power piston. 3. Install retainer and seat. 4. Install filter over pushrod eyelet and into power piston. 5. Install retaining ring onto air valve pushrod assembly. 6. Install reaction bumper, air valve spring, reaction piston and reaction disc onto reaction body. 7. Install reaction body, then reaction body retainer. 8. Lubricate inside diameter of secondary diaphragm lip, inside diameter of primary diaphragm lip and the secondary piston bearing with a thin layer of silicone grease. 9. Install secondary diaphragm into the secondary support plate, Fig. 8. 10. Install secondary diaphragm and secondary support plate over the power piston and pushrod assembly. 11. Install secondary piston bearing into housing divider with flat surface of bearing on the same side as the six raised lugs on the divider. Page 8257 Symbol Identification Page 480 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Page 7173 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 5021 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 7397 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 4986 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Initial Inspection and Diagnostic Overview Side Marker Lamp: Initial Inspection and Diagnostic Overview 1. Check condition of STOP-HAZ and TAIL LPS Fuse(s), if fuse(s) is blown, locate and repair source of overload, replace fuse. Page 8604 Rear Door Power Window Page 5297 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 3523 Intake Manifold Tuning Valve: Service and Repair Intake Manifold Tuning Valve Remove or Disconnect 1. Electrical connector. 2. Tuning valve attaching screws. 3. Tuning valve. 4. O-ring seal. - If the tuning valve is to be reused, discard seal. NOTE The tuning valve is an electrical component. Do NOT soak it in any liquid cleaner or solvent, damage may result. - To avoid breaking tuning valve mounting ears. alternately tighten attaching screws until they engage mounting ear surface, then tighten each screw to specified torque. Install or Connect 1. Lubricate new intake manifold tuning valve O-ring seal with clean engine oil. 2. Intake manifold tuning valve. 3. Attaching screws. NOTE Refer to "Thread-Locking Material" following article. Tighten Intake manifold tuning valve attaching screws to 2.0 Nm (18 lb.in.) 4. Electrical connector Thread-Locking Material Important The hardware used to attach the Throttle Position (TP) sensor, Idle Air Control (IAC) valve, Intake Manifold Tuning Valve and MAP sensor, are coated with thread-locking adhesive. If any of these parts are removed for service, inspect the attaching screw threads. There should be enough thread-locking material (adhesive or compound) on the threads to insure proper relocking. If not, clean the screw threads and apply Loctite 262, or equivalent, to the threads before reassembly. Replacement screws are included in the service screw assortment package. New attaching hardware is included in the service packages. Page 7257 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you A/C Refrigerant - Contamination Refrigerant: Technical Service Bulletins A/C Refrigerant - Contamination File In Section: 1 - HVAC Bulletin No.: 43-12-23 Date: September, 1994 Subject: Contaminated A/C Refrigerant Models: 1994 and Prior Passenger Cars and Trucks with R12 Air Conditioning Systems Government regulations limit the production of R12 refrigerant, commonly referred to as Freon, during 1994/1995 and restrict manufacture of new R12 material effective January 1, 1996. As R12 prices rise and supplies are depleted, it is anticipated non-approved substitute refrigerants and/or poor quality R12 material sold as new or reprocessed may become more prevalent. The Mobile Air Conditioning Society (MACS) recently expressed concern over reports of the sale of R12 refrigerant containing as high as 15% contamination by R22, a refrigerant commonly used in stationary home systems but unsuitable for use in mobile units. GM dealers should be careful to protect against contaminating their existing supplies of R12 or the A/C systems in customers' vehicles they service by dealing with reputable suppliers. All R12 refrigerant purchased for warranty repairs should be purchased through GM SPO to ensure GM quality standards are met. The use of non-approved R12 refrigerant substitutes, some of which contain flammable materials, has also been reported by MACS. These products are available to "do-it-yourselfers" who, in many cases, believe they are harmless replacements for the small cans of R12 used so commonly in the past. Once added to the A/C system, the vehicle can no longer be serviced using R12 recovery/recycling equipment without: - Risking permanent damage to recovery/recycling equipment - Contaminating the previously recovered R12 material in the recovery tank - Spreading the contamination when the recovered material is used to charge other vehicles or - Possible loss of the recovered material if the contaminated level is high enough to activate the air purge system Contaminated refrigerant also impacts customer satisfaction through poor vehicle A/C performance and loss of A/C system compressor/component durability. System or component failure resulting from the use of refrigerant which does not meet GM specification is not covered by the "New Vehicle Warranty". Unfortunately, there is no simple method to identify if a "do-it-yourselfer" or repair shop has added to or recharged a system with a non-approved refrigerant. The inability to protect against the spread of contaminated refrigerant threatens the recycling program and the industry's desire to maximize use of the remaining R12 supply. Beginning in 1993, General Motors STG, Harrison Division, Research Labs and Kent-Moore worked in conjunction with suppliers of various technologies to develop a tester to identify contaminated refrigerant in vehicle A/C systems before recovery. During development of the technology, several dealer service manager focus group studies were conducted to identify design features to best suit dealership needs. The discussions and surveys clearly indicated the desire for a dedicated instrument, permanently mounted to the refrigerant recovery cart to ensure ALL vehicles are automatically tested prior to recovering refrigerant. Testing ALL refrigerant for contamination prior to recovery is the ONLY means to ensure customer satisfaction, protect recovery equipment and avoid unintentional venting of refrigerant by your dealership. General Motors has evaluated all available technology for this project and only the J 39851 R12 "Pureguard" meets General Motors' specifications. The J 39851 R12 Pureguard Refrigerant Monitor has been classified as an essential tool and will be shipped by Kent-Moore to your dealership beginning in September of 1994. The essential price of the R12 "Pureguard" is $561 (for Canadian dealers the price is $800 Canadian). If your dealership has multiple R12 recovery equipment, additional units may be ordered from Kent-Moore for $561 at 1-800-345-2233. Features of the R12 "Pureguard" include: - Universally mounts to R12 Recovery Equipment - Automatically interrupts power to the Recovery Equipment when contaminated refrigerant is identified - Fully automatic design does not require technician action, training or interpretation - LCD displays Pureguard functions Page 2728 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Capacity Specifications Fluid - M/T: Capacity Specifications 5 Speed 4.4 pt (US) Page 4641 Brake Caliper: Description and Operation Fig. 1 Exploded View The Delco-Moraine Single Piston Caliper is held in place by two mounting bolts. The caliper assembly, Fig. 1, slides on its mounting surfaces. Upon brake application, hydraulic pressure against the piston forces the inboard pad against the inboard side of the disc. This action causes the caliper assembly to slide until the outboard pad comes into contact with the disc, which in turn creates a slowing or stopping action. Page 4981 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 4275 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using a torque wrench. 8. Continue tightening pinion nut in small increments until 35-40 inch lbs. of bearing preload is obtained with new bearings or 20-25 inch lbs. of bearing preload is obtained with used bearings, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 4 - Pinion Fig. 5 Drive pinion & bearing shim adjustment 1. Install front pinion bearing cup in carrier using tool J-7817 or equivalent. 2. Install spacer (E) into carrier bore, Fig. 5. 3. Slide rear pinion bearing and cap (F) onto thru bolt (D) and rear bearing into axle housing. 4. Install thru bolt (D), rear bearing and cap (F) into axle housing. 5. Assemble front bearing cone (A) and spacer (B) onto thru bolt. 6. Rotate nut and shaft while increasing torque on nut until a rotational torque of 15-22 inch lbs. is obtained. Rotate thru bolt back and forth when tightening nut to properly seat bearing. 7. Install discs on thru bolt assembly as shown in Fig. 5. Position carrier so dial indicator contact rod is directly over gauging area of gauge plate J-35118-2. Discs must be fully seated in side bearing bores. 8. Install bearing caps over gauge shaft discs, then the cap attaching bolts. torque attaching bolts to 40 ft. lbs. 9. With dial indicator rod contacting gauging area of J-35118-2, rock gauge shaft back and forth until dial indicator measures the greatest deflection, then zero dial indicator. 10. Rotate gauge shaft until shaft does not contact gauge plate, then note measurement. 11. Select correct pinion shim as follows: a. If reusing production pinion, and pinion is marked with a ``+,'' correct shim will have a thickness equal to gauge reading minus amount specified on pinion. b. If reusing production pinion, and pinion is marked with a `` - ,'' correct shim will have a thickness equal to gauge reading plus amount specified on pinion. c. If using a production or service pinion which has no marking, correct shim will have a thickness equal to gauge reading. 12. Install selected pinion shim into carrier, then press rear pinion bearing cup into carrier using tool J-5590 or equivalent. 13. Press rear pinion bearing onto pinion using a bearing installation tool, then install pinion in carrier. 14. Install collapsible spacer and front bearing onto pinion while supporting pinion under head. 15. Install oil seal, companion flange and new nut on pinion, then tighten pinion nut until a rotating torque of 10-25 inch lbs. with new bearings or 5-12 inch lbs. with original bearings is obtained while rotating pinion forwards to seat bearings. 16. If preload is excessive after tightening pinion nut, replace collapsible spacer and repeat steps 14 and 15. Page 3916 Fluid - A/T: Testing and Inspection Turbo Hydra-Matic 4L60 (700-R4) Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface, engine idling in park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, If fluid level is too low, complete loss of drive may occur especially when cold, Which can cause transmission failure. Every 100,000 miles, the oil should be drained, the pan removed, the screen should be cleaned or replaced if applicable, and fresh fluid added. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or use as a tow vehicle, this maintenance should be performed every 15,000 miles. Page 3070 Vehicle Speed Sensor Signal Buffer: Description and Operation Speed Sensor Buffer The Vehicle Speed Sensor Buffer (DRAC) processes inputs from the Vehicle Speed Sensor (VSS) and outputs signals to the Speedometer, Electronic Control Module (ECM), Cruise Control Module and the Rear Wheel Antilock Brake (RWAL) Module. The VSS is made up of a 40-tooth rotor and a coil mounted on the transmission. As each rotor tooth nears the coil, the coil produces an AC voltage pulse. Each revolution of the rotor produces 40 AC voltage pulses. As the vehicle speed increases, the number of AC voltage pulses per second increases. The Vehicle Speed Sensor Buffer (DRAC) takes the voltage pulses from the VSS and uses them to open and close four solid-state output switches to ground at a rate proportional to vehicle speed. The Speedometer switch opens and closes at the same rate as the VSS pulses. The ECM and Cruise Control switches open and close at half the rate of the VSS pulses. The RWAL switch opens and closes at a rate seven times the VSS pulses. The Vehicle Speed Sensor Buffer (DRAC) is matched to the vehicle based on transmission, final drive ratio and tire size. It is important to ensure that the correct Vehicle Speed Sensor Buffer (DRAC) is installed in the vehicle if replacement is necessary. Page 2358 Coolant Temperature Sensor/Switch (For Computer): Description and Operation ECT Circuit (Typical) Engine Coolant Temperature Sensor PURPOSE Engine Coolant Temperature (ECT) Sensor is used to control: Exhaust Gas Recirculation (EGR) - Fuel delivery - Idle Air Control (IAC) - Ignition Control (IC) - Torque Converter Clutch (TCC) OPERATION The ECT sensor is a thermistor that is located in the engine coolant flow. Low coolant temperature sensor produces a high resistance (100,000 ohms at -40°C/-40°F). High coolant temperature, produces a low resistance (70 ohms at 130°C/266°F). The control module sends a 5.0 volt signal to the ECT through a resistor in the control module and measures the voltage. The voltage will be high when the engine is cold and low when the engine is hot. Engine coolant temperature affects most systems controlled by the control module. The control module uses information from the ECT to calculate spark advance as follows: Cold engine results in more spark advance. - Hot engine results in less spark advance. Page 5707 Ball Joint: Service and Repair Lower Control Arms And Components Disconnecting The Lower Ball Joint Page 5464 Figure 7 Figure 8 Figure 9 Figure 10 Page 997 Disclaimer Page 3393 Use applicable labor time guide for labor hours. Page 1295 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 6151 3. Center the J 8433-1 puller crossbar in the countersunk center hole of the J 33024 clutch coil installer. Install the J 34992-2 through bolts and washers through the crossbar slots and thread them, into the holding fixture J 34992 to full fixture thickness. 4. Turn the center forcing screw of the J 8433-1 puller crossbar to force the clutch coil onto the front head. Be sure clutch coil and J 33024 installer stay "in-line" during installation. Staking Clutch Coil To Front Head 5. When coil is fully seated on the front head, use a 1/8" diameter drift punch and stake the front head at three (3) places 120° apart. to ensure clutch coil remaining in position. Details Of Stakes In Front Head For Clutch Coil - Stake size should be only one half the area of the punch tip and only approximately 0.28-0.35mm (0.10-0.015") deep. 6. Install rotor and bearing assembly and the clutch plate and hub assembly according as described previously. Service and Repair Governor: Service and Repair 1. Raise and support vehicle. 2. Remove governor cover from case using extreme care not to damage cover. If cover is damaged, it must be replaced. 3. Remove governor. 4. Reverse procedure to install and check fluid level. Page 4360 Fig. 3 Axle, Hub & Drum Components. 1. Using a soft faced mallet, tap axle shaft flange lightly to loosen shaft. 2. Remove axle shaft attaching bolts, Fig. 3, then grip axle shaft rib with pliers and twist to start shaft removal. 3. Remove axle shaft from axle tube. 4. Reverse procedure to install. Wheel Bearing REAR WHEL BEARINGS 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Axle Shaft, Replace REAR AXLE SHAFT Fig. 3 Removing differential pinion shaft 1. Raise vehicle and remove wheel and brake drum. 2. Drain lube from carrier and remove cover. 3. Remove differential pinion shaft lock screw and remove differential pinion shaft, Fig. 3. 4. Pull flanged end of axle shaft toward center of vehicle and remove C-lock from button end of shaft. 5. Remove axle shaft from housing, being careful not to damage seal. Page 4629 from contacting these areas. Clean any fluid that may drip onto wheel cylinders or calipers to prevent corrosion. Always re-seal and wipe off brake fluid containers to prevent spills. Tools Required: J 39177 Valve Pressure Bleeding Tool (three required) Note: You can also use a modified J 35856 Valve Pressure Bleeding Tool providing you remove the dimple from it first. J 29567 Universal Brake Bleeder Adaptor (use for pressure bleed) J 29532 Diaphragm Type Brake Bleeder (brake fluid pressure tank for pressure bleed) TK 00000 Tech-1 Scan Tool TK 02650 RWAL/4WAL Cartridge Kit (include proper cable/adaptor), or 7000001 Mass Storage Cartridge Kit (include proper cable/adaptor) 3000003 Mass Storage Cartridge (include proper cable/adaptor) MANUAL BLEED PROCEDURE When a pressure bleeder is not available, use the (two person) manual bleed procedure. One person will push on the brake pedal while the other person will open and close the bleed valves. Important You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Begin by opening the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (Figure 2). 2. Attach the valve pressure bleeding tool J 39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (Figure 3). Tighten tool J 39177 only finger tight. Note: It is not necessary to attach bleeding tool J 39177 to the combination valve when using the manual bleed procedure. 3. Bleed each wheel in the following sequence: Locations Engine Wiring, LH Side Cruise Control - Works Intermittently Cruise Control Switch: Customer Interest Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Page 530 Diagnostic Circuit Circuit Description The diagnostic circuit check is an organized approach to identifying a problem created by an electronic engine control system malfunction. It must be the starting point for any driveability complaint diagnosis, because it directs the service technician to the next logical step in diagnosing the complaint. Understanding the chart and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of good parts. Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. This step is a check for the proper operation of the "Service Engine Soon" light. The "SES" light should be "ON" steady. 2. No "SES" light at this point indicates that there is a problem with the "SES" light circuit or the control module control of that circuit. 3. This test checks the ability of the control module to control the "SES" light. With the diagnostic terminal grounded, the "SES" light should flash a Code 12 three times, followed by any trouble code stored in memory. A PROM error may result in the inability to flash Code 12. 4. Most of the diagnostic charts use a Tech 1 to aid diagnosis, therefore, serial data must be available. If a PROM error is present, the control module may have been able to flash Code 12 or 51, but not transmit serial data. 5. Although the control module is powered up, a "Cranks But Will Not Run" symptom could exist because of an control module or system problem. 6. This step will isolate if the customer complaint is a "SES" light or a driveability problem with no "SES" light. Refer to Computers and Control Systems for a list of valid codes. An invalid code may be the result of a faulty "Scan" tool, PROM or control module. See: Powertrain Management/Computers and Control Systems 7. Comparison of actual control system data with the typical valves is a quick check to determine if any parameter is not within limits. Keep in mind that a base engine problem (i.e., advanced cam timing) may substantially alter sensor values. 8. If the actual data is not within the typical values established, refer to Computers and Control Systems. See: Powertrain Management/Computers and Control Systems Page 6754 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 6681 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 2532 Manifold Pressure/Vacuum Sensor: Description and Operation Map Sensor Circuit (GM Generic) Manifold Absolute Pressure (MAP) Sensor PURPOSE The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. As intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the control module to automatically adjust for different altitudes. The PCM uses information from the MAP sensor to calculate spark advance and fuel as follows: Low MAP output voltage (low pressure) results in more spark advance. - High MAP output voltage (high pressure) results in less spark advance. - Low MAP output voltage (low pressure) results in less fuel. - High MAP output voltage (high pressure) results in more fuel. OPERATION The control module supplies a 5 volt reference signal to the MAP sensor and the sensor provides a path to ground through its variable resistor. The control module by monitoring the sensor output voltage can determine the manifold pressure. A closed throttle on engine coastdown will produce a relatively low MAP output, while a wide open throttle will produce a high output. At higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum. At lower pressure output voltage will be about 1 to 2 volts at idle. A failure in the MAP sensor circuit should set Diagnostic Trouble Codes (DTC) 33 or 34 with PCM/ECM systems and DTC P0107 or P0108 with VCM systems. Page 548 Brake Light Switch: Service and Repair Fig. 2 Stop Light Switch Installation 1. Disconnect battery ground cable. 2. Disconnect wiring connector from brake light switch located on brake pedal bracket. 3. Pull switch from mounting bracket. 4. Depress brake pedal, then push new switch into clip until shoulder bottoms out, Fig. 2. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed .53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Page 6729 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 383 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 2716 Spark Plug: Specifications Spark Plugs 22 ft.lb Coolant Temperature Sensor Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Sensor HP Engine RH Front Side Of Engine. Front Of Engine Applicable to: 4.3L/V6-262 HP Engine Page 5108 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Description and Operation Water In Fuel Indicator: Description and Operation The Water In Fuel warning system employs a fuel detector integral with the fuel filter and fuel heater and mounted on the engine. When 2.2 ounces of water more has collected in the filter, the Water In Fuel lamp on the instrument panel will light. After the light comes on, the filter should be drained as soon as possible and must be drained within 2 hours of operation. Page 5824 2. Fill the injury (puncture) to keep moisture out. 3. Seal the inner liner with a repair unit to prevent air loss. External Inspection 1. Prior to demounting, inspect the tire surface, the valve and the wheel for the source of the leak by using a water and soap solution. Mark the injured area and totally deflate the tire by removing the valve core. 2. Demount the tire from the wheel and place the tire on a well-lighted spreader. Internal Inspection 1. Spread the beads and mark the puncture with a tire crayon. 2. Inspect the inner tire for any signs of internal damage. 3. Remove the puncturing object, noting the direction of the penetration. 4. Probe the injury with a blunt awl in order to determine the extent and direction of the injury. 5. Remove any loose foreign material from the injury. 6. Punctures exceeding 6.35 mm (1/4") should not be repaired. Cleaning 1. Clean the area around the puncture thoroughly with a proper liner cleaner, clean cloth and a scraper. This step serves to remove dirt and mold lubricants to insure proper adhesion and non-contamination of the buffing tool. 2. Refer to information on the product or manufacturer's Material Safety Data Sheet and follow guidelines for handling and disposal. Clean the Injury Channel Page 1018 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Specifications Reverse Gear Shaft: Specifications Reverse Idler Shaft Bolt ....................................................................................................................... ................................................................... 17 ft. lbs. Page 4144 Clutch Fluid: Fluid Type Specifications Hydraulic Clutch Fluid ........................................................................................................................................................... DOT 3 or DOT 4 Brake Fluid Page 5485 Relay Box: Electrical Diagrams Convenience Center (without Digital Cluster) Page 3282 Fuel Pressure Test Port: Service and Repair Fuel Pressure Connection CLEAN Area around fuel pressure connection with GM X-30A or equivalent. REMOVE OR DISCONNECT - Negative battery terminal. - Relieve fuel system pressure. - Fuel pressure connection and seal. Discard seal. INSTALL OR CONNECT - New seal on fuel pressure connection. - Fuel pressure connection in fuel rail. Tighten Fuel pressure connection assembly to 10.0 N-m (88 lb. in.). - Tighten fuel filler cap. - Negative battery terminal. INSPECT - Turn ignition switch to the "ON" position for two seconds, then turn to the "OFF" position for ten seconds. Again turn to the "ON" position, and check for fuel leaks. NOTE Any time the battery is disconnected, the programmed position of the IAC valve pintle is lost, and replaced with a default value. To return the IAC valve pintle to the correct position, perform the following procedure: - Disconnect negative battery for at least ten seconds to clear control module memory. (Ensure ignition is "OFF".) - Reconnect negative battery cable. - "START" engine and allow engine to reach operating temperature. Check for proper idle operation. Page 1240 The pressure bleeding equipment must be of the diaphragm type. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. Important You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Begin by attaching the pressure bleeder adaptor J 29567 to the master cylinder (Figure 1). 2. Fill the pressure bleeder tank J 29532 at least 2/3 full with Delco Supreme No. 11 Hydraulic 8rake Fluid (GM P/N 1052535) or an equivalent DOT 3 motor vehicle brake fluid. The bleeder tank must be bled each time brake fluid is added. 3. Charge the bleeder tank to 140-170 kPa (20-25 psi) and connect the hose from the bleeder tank to the bleeder adaptor. 4. Open the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (Figure 2). 5. Attach the valve pressure bleeding tools J 39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (Figure 3) and to the combination valve (Figure 4). Tighten tool J 39177 only finger tight. 6. Open the pressure bleeder tank valve. 7. Bleed each wheel in the following sequence: ^ Right rear ^ Left rear ^ Right front ^ Left front Note: Page 1353 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Page 5265 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 7396 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Timken/Rockwell - 12 Inch Ring Gear Pinion Bearing: Service and Repair Timken/Rockwell - 12 Inch Ring Gear Fig. 1 Exploded View Of Timken/Rockwell Drive Axle With 12 inch Ring Gear DISASSEMBLY 1. Tap or press pinion from cage, taking care not to damage shaft threads, then remove outer pinion bearing, Fig. 1. 2. Remove spacer from pinion, then the inner bearing, using suitable separator and press or puller. 3. If straddle bearing must be replaced, remove snap ring and washer, then the bearing, using suitable puller. 4. If bearings are to be replaced, press outer races from bearing cage, taking care not to distort cage. 5. Inspect components as outlined, and replace as needed, keeping components in order for assembly. ASSEMBLY & PRELOAD 1. When installing new cups, press them firmly against pinion bearing cage shoulders. 2. Lubricate bearings and cups with suitable lubricant. 3. Press rear thrust and radial bearings firmly against pinion shoulders, using suitable sleeve that will bear only on bearing inner race. 4. Install radial bearing lock ring, then squeeze ring into pinion shaft groove. 5. Insert pinion and bearing assembly in pinion cage and position spacer or spacer combination over pinion shaft. 6. Press front bearing firmly against spacer. 7. Rotate cage several revolutions to assure normal bearing contact. 8. Press flange or yoke against forward bearing and install washer and pinion shaft nut. 9. Place pinion and cage assembly over carrier studs, hold flange with suitable tool and torque pinion shaft nut to 240 ft. lbs. 10. Check pinion bearing preload torque. If rotating torque is not within 5 to 15 pound inches, disassemble, adjust spacer, reassemble, and recheck preload torque. Use thinner spacer to increase or thicker spacer to decrease preload. Page 8306 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 5218 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Specifications Valve Guide: Specifications Inside Diameter Inside Diameter Inside Diameter Standard 0.3437 in Page 2966 Oxygen Sensor: Description and Operation Exhaust Oxygen Sensor (02) PURPOSE The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315°C (600°F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Oxygen Sensor Output Voltage vs. Air/Fuel Ratio The difference in oxygen concentration in the narrow range of optimum air/fuel ratio causes a large voltage change that is easily measured. OPERATION A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. Page 4844 12. Install secondary piston bearing and housing divider over power piston assembly and pushrod. 13. Install primary diaphragm into the primary support plate, Fig. 8. 14. Fold primary diaphragm up away from the primary support plate, then install primary diaphragm and support plate over power piston and pushrod assembly. 15. Fold primary diaphragm back into position and pull the outside edge of diaphragm over formed flange of housing divider. 16. Install new diaphragm retainer. Ensure retainer is fully seated. 17. Install silencer, reaction retainer and piston rod. 18. Lubricate inside and outside diameters of primary piston bearings with silicone grease. 19. Install primary piston bearing into rear housing. 20. Install power piston assembly into rear housing, then the return spring. 21. Mount housing to holding fixture and turn fixture handle to lock the front and rear housings, Fig. 4. Fig. 5 Brake Booster Lock Tab & Staking Positions 22. Stake housing in locations shown, Fig. 5. Do not stake a tab that has been staked previously. 23. Lubricate inside and outside edges of grommet and front housing seal, then install grommet and seal. 24. Install vacuum check valve, silencer and boot. 25. Ensure piston rod depth is within specifications using gauge tool No. J-37839 or equivalent. Page 159 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 5019 Symbol Identification Engine - GM dexos 1 and dexos 2(R) Oil Specifications Engine Oil: Technical Service Bulletins Engine - GM dexos 1 and dexos 2(R) Oil Specifications INFORMATION Bulletin No.: 11-00-90-001 Date: March 14, 2011 Subject: Global Information for GM dexos1(TM) and GM dexos2(TM) Engine Oil Specifications for Spark Ignited and Diesel Engines, Available Licensed Brands, and Service Fill for Adding or Complete Oil Change Models: 2012 and Prior GM Passenger Cars and Trucks Excluding All Vehicles Equipped with Duramax(TM) Diesel Engines GM dexos 1(TM) Information Center Website Refer to the following General Motors website for dexos 1(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 1(TM) Engine Oil Trademark and Icons The dexos(TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos‹›(TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos‹›(TM) specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 1(TM) engine oil. GM dexos 1(TM) Engine Oil Specification Important General Motors dexos 1(TM) engine oil specification replaces the previous General Motors specifications GM6094M, GM4718M and GM-LL-A-025 for most GM gasoline engines. The oil specified for use in GM passenger cars and trucks, PRIOR to the 2011 model year remains acceptable for those previous vehicles. However, dexos 1(TM) is backward compatible and can be used in those older vehicles. In North America, starting with the 2011 model year, GM introduced dexos 1(TM) certified engine oil as a factory fill and service fill for gasoline engines. The reasons for the new engine oil specification are as follows: - To meet environmental goals such as increasing fuel efficiency and reducing engine emissions. - To promote long engine life. - To minimize the number of engine oil changes in order to help meet the goal of lessening the industry's overall dependence on crude oil. dexos 1(TM) is a GM-developed engine oil specification that has been designed to provide the following benefits: - Further improve fuel economy, to meet future corporate average fuel economy (CAFE) requirements and fuel economy retention by allowing the oil to maintain its fuel economy benefits throughout the life of the oil. - More robust formulations for added engine protection and aeration performance. Page 3861 Page 2867 Oxygen Sensor: Specifications Sensor Voltage Range Sensor Voltage Range Sensor Voltage (Closed Loop) 0.1 to 1.0 V Campaign - Interior Front Door Handles Technical Service Bulletin # 06027A Date: 070523 Campaign - Interior Front Door Handles Bulletin No.: 06027A Date: May 23, 2007 SPECIAL COVERAGE Subject: 06027A - SPECIAL COVERAGE ADJUSTMENT - CLASS ACTION SETTLEMENT - INTERIOR DOOR HANDLE SPRING BREAKAGE Models: 1982-1994 CHEVROLET S/T PICKUP AND UTILITY 1982-1994 GMC S/T PICKUP AND UTILITY, JIMMY 1991-1994 OLDSMOBILE BRAVADA INVOLVED IN SOUTH CAROLINA CLASS ACTION SETTLEMENT Supercede: The expiration date for this special coverage has been extended to December 31, 2007. The mailing of letters to customers was delayed. Letters will be mailed to customers on May 30, 2007. Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Condition Some customers of 1982-1994 Chevrolet S/T pickup and utility vehicles; 1982-1994 GMC S/T pickup and utility vehicles; and 1991-1994 Oldsmobile Bravada vehicles are entitled to the benefits of a class action settlement. The benefits are listed below and customers will be provided with a letter to present to dealers that details the remedy that they chose. Special Coverage Adjustment This special coverage covers the conditions described below until December 31, 2007. Customers may have any combination of the benefits listed below. Please see the customer's letter to determine the appropriate remedy. Reimbursement - Customers who have replaced an interior front door handle assembly have already submitted a request for reimbursement. GM is handling the reimbursements. There is no action required from the dealer. Replacement of broken interior front door handle assembly(s) - Some customers have chosen to receive a replacement interior front door handle assembly(s). Dealers are to provide the customer with the assembly(s) at no charge. The customer is to self-install or pay the dealer for the installation of the assembly(s). Application of lithium grease - Customers who have the original front door handle assembly(s) in which the spring is not broken, are entitled to have the spring(s) greased. Dealers are to apply lithium grease to the unbroken spring(s) of the original front door handle assembly(s) at no charge. Vehicles Involved Customers involved will present the dealer their vehicle with a letter that authorizes the repair. If the customer requests a new interior front door handle, dealer must verify it replaces a broken interior front door handle assembly. Description and Operation Data Link Connector: Description and Operation ALDL Connector PURPOSE The Data Link Connector (DLC) provides a means of communicating with the PCM concerning engine and transmission operating parameters and accessing Diagnostic Trouble Codes (DTC). OPERATION The PCM communicates a variety of information through the Serial Data Line (DLC terminal "M"). The data is transmitted at a high frequency which requires a Tech 1 diagnostic computer (scan) tool for interpretation. There are several other non-OEM scan tools available for displaying the same information. LOCATION The Data Link Connector is located in the passenger compartment. Page 5253 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 8304 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 767 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you TCC Solenoid Rear Of Engine Page 7399 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 6255 Install or Connect 1. Follow applicable on-vehicle procedures. 2. To Leak Test, install leak Test Fixture J 9625-A (Fig. 30) on rear head of compressor and connect gage charging lines and J 38100-C Refrigerant Recovery System. Pressurize suction and high-side of compressor with Refrigerant-12 vapor to drum pressure. Temporarily install the shaft nut and turn compressor shaft in normal direction of rotation several times by hand. Leak test the seal area and correct any leak found. Recover the refrigerant. Remove shaft nut. Page 157 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 5741 Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: All Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Locations Quad Driver: Locations Quad/Output drivers are hard wired onto the ECM/PCM/VCM. Page 3891 Page 4552 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 6385 89-93 - Suction hose - 96068490 89-93 - Discharge hose - 96068489 Suction hose: 85-86 - 91172086 85-86 Dealer installed: 91172087 87-88 - 91172088 89-93 - w/turbo - 96069121 - w/o turbo - 91172089 Discharge hose: 85-86 - 91172082 85-86 Dealer installed: 91172083 87-88 - 91172084 89-93 - 96069024 1989-93 Tracker 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the Retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 550 grams (1.21 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer - 91172080 Adapter, Low Side - 91172092 Page 6071 2. Cables (60 and 65) to the control assembly (63) and the heater assembly. 3. Control assembly (63). Page 8318 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 4249 Differential Clutch: Service and Repair 10 1/2 Inch Ring Gear Cam Gear Clutch Fig. 6 Cam Gear Thrust Ring Removal. Eaton Locking Differential Fig. 4 Exploded View Of Cam Gear Assembly. Eaton Locking Differential 1. Measure and record overall length of cam gear assembly from front face of gear to back face of thrust ring, including shim. 2. Compress disc pack and insert jaws of bearing separator tool No. J-22912 or equivalent between thrust ring and top clutch disc with chamfer of separator facing thrust ring. 3. Support separator in press and press cam gear from thrust ring using suitable spacer, Fig. 3, keeping components in order as cam gear is removed. 4. Remove discs, spring and cam plate from gear, Fig. 4, clean and inspect components and replace any that are damaged or excessively worn. Do not replace cam gear and/or thrust ring unless necessary. If ring or gear is excessively worn or scored, inspect bore in case. If case bore is scored, differential assembly must be replaced. If cam gear or thrust ring is replaced, shim thickness must be selected to provide original assembly dimension and proper differential pinion backlash. 5. Position cam gear with hub facing up and install cam plate with cam form down to mesh with form on gear. 6. Assemble two eared discs and one disc with large splines on cam plate, starting with eared disc as shown in Fig. 4, then install wave spring. If components are reused, they must be installed in original position. 7. Assemble four eared discs and three splined discs on cam gear, starting with eared disc as shown in Fig. 4. 8. Position cam gear assembly in press and install thrust ring on hub of gear, ensuring that ring is square with hub. 9. Compress disc pack to prevent disc from being trapped, then press thrust ring onto cam gear until ring is seated against shoulder of gear. 10. Inspect assembly and ensure that components are properly installed. Side Gear (LH) Clutch Page 1072 Processes shown in the Table 3 are capable of recycling waste engine coolants (DEX-COOL(R) or conventional) to a conventional (green) coolant. Recycling conventional coolant can be accomplished at your facility by a technician using approved EQUIPMENT (listed by model number in Table 3), or by an approved coolant recycling SERVICE which may recycle the coolant at your facility or at an offsite operation. Refer to the table for GM approved coolant recyclers in either of these two categories. Should you decide to recycle the coolant yourself, strict adherence to the operating procedures is imperative. Use ONLY the inhibitor chemicals supplied by the respective (GM approved) recycling equipment manufacturer. Sealing Tablets Cooling System Sealing Tablets (Seal Tabs) should not be used as a regular maintenance item after servicing an engine cooling system. Discoloration of coolant can occur if too many seal tabs have been inserted into the cooling system. This can occur if seal tabs are repeatedly used over the service life of a vehicle. Where appropriate, seal tabs may be used if diagnostics fail to repair a small leak in the cooling system. When a condition appears in which seal tabs may be recommended, a specific bulletin will be released describing their proper usage. Water Quality The integrity of the coolant is dependent upon the quality of DEX-COOL(R) and water. DEX-COOL(R) is a product that has enhanced protection capability as well as an extended service interval. These enhanced properties may be jeopardized by combining DEX-COOL(R) with poor quality water. If you suspect the water in your area of being poor quality, it is recommended you use distilled or de-ionized water with DEX-COOL(R). "Pink" DEX-COOL(R) DEX-COOL(R) is orange in color to distinguish it from other coolants. Due to inconsistencies in the mixing of the dyes used with DEX-COOL(R), some batches may appear pink after time. The color shift from orange to pink does not affect the integrity of the coolant, and still maintains the 5 yr/150,000 mile (240,000 km) service interval. Back Service Only use DEX-COOL(R) if the vehicle was originally equipped with DEX-COOL(R). Page 6606 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 8582 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 5387 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 4387 5. Disengage cross trunnions, still attached to flange yoke, from coupling yoke. Pull flange yoke and cross from centering ball on ball support tube yoke. The ball socket is part of the flange yoke. The ball on some joints is not replaceable. The joints with a replaceable ball can be recognized as shown in Fig. 15. Do not attempt to remove solid ball, as removal tool may be damaged. 6. Pry seal from ball cavity, then remove washers, spring and shoes, Fig. 16. Fig. 17 Removing Centering Ball Ball Socket 1. To remove ball, separate universal joint between coupling yoke and flange yoke by pressing out trunnion bearing in coupling yoke. Pull flange yoke and cross with ball socket from centering ball as a unit. 2. Clean and inspect ball seat insert bushing for wear. If worn, replace flange yoke and cross assembly. 3. Pry seal from ball cavity, then remove washers, spring and ball seats. 4. Clean and inspect centering ball surface, seal, ball seats, spring and washer. If parts are worn or broken, replace with a service kit. 5. Remove centering ball as shown in Fig. 17, using components of tool C-4365 or equivalent. Install components as shown, and draw ball off ball stud. Fig. 12 Alignment Punch Marks Fig. 18 Inserting Cross Into Yoke Page 5131 Daytime Running Lamps, I/P Wiring Page 6915 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Adjustments Idle Speed Control Motor: Adjustments Base Idle Speed is not adjustable on this engine and is controlled by the control module. Refer to FUEL SUPPLY AND AIR INDUCTION/ADJUSTMENT PROCEDURES for adjusting Controlled Idle Speed. Page 5434 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7247 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 7391 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 402 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Wheels (Steel) - Damage Due to Improper Mounting Wheels: All Technical Service Bulletins Wheels (Steel) - Damage Due to Improper Mounting Number: 92-232-3E Section: 3E Date: JUNE 1992 Corporate Bulletin No.: 233002 ASE No.: A4 Subject: AVOIDING DAMAGE TO STEEL WHEELS FROM IMPROPER WHEEL/TIRE CHANGING TECHNIQUES Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH STEEL WHEELS It is important to use proper procedures to prevent damage to either the tire mounting surface or the wheel mounting holes. Damage can result from the improper wheel attachment or tire mounting techniques on vehicles with steel wheels. 1. IMPROPER TIRE CHANGING TECHNIQUES: It takes about 70 seconds for the air to completely exhaust from a large tire. If the technician doesn't wait this amount of time after removing the valve core, the bead breaker on the tire change could put enough force on the tire to bend the wheel at the mounting surface. Such damage can result in vibration, shimmy, and under severe usage (i.e. police vehicle) lead to cracking. 2. OVER TORQUING OF THE WHEEL NUTS: The service specification for wheel nuts is listed in the Service Manuals. Some wheels have been observed with wheel nuts that were over torqued by as much as 50 percent. This may damage the wheel mounting holes and may also lead to cracks. I. PROPER TIRE CHANGING TECHNIQUES: Completely deflate the tire before attempting to break the tire bead loose. MOUNTING SURFACE CHECKING PROCEDURE Page 7341 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 14 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 5118 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 4987 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Locations Expansion Block/Orifice Tube: Locations Fitting And Hose Installation Evaporator And Blower Assembly Component View Page 1576 GEN Indicator Does Not Light W/Ign. In Run and Engine Stopped Generator (Gen) Indicator Does Not Light With Ignition Switch In RUN And Engine Stopped Page 205 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Temp Gage Indic. Hot W/ENG Cool Below Oper Temp and Ign In Run Temperature Gage Indicates Hot With Engine Coolant Below Operating Temperature And Ignition Switch In RUN New Windshield/Glass Urethane Adhesive Caulking Kit Windshield: All Technical Service Bulletins New Windshield/Glass Urethane Adhesive Caulking Kit File In Section: 10 - Body Bulletin No.: 83-15-16 Date: October, 1998 INFORMATION Subject: New Windshield and Stationary Glass Urethane Adhesive Caulking Kit Models: 1990-99 All Passenger Cars and Trucks As a result of a change from standard viscosity urethane to high-viscosity urethane, a new Urethane Adhesive Caulking Kit, P/N 12346392, is now available from GMSPO. This kit contains the "High Viscosity" Urethane Adhesive for thicker and more consistent bead size applications. When applied properly, this new high viscosity urethane in many instances will eliminate the need for depth setting blocks or the damming material to control squeeze out. The following is the contents of the new kit: Like the standard viscosity urethane contained in kit (P/N 12346284) that it replaces, it is a one-part, moisture cure product with curing times that vary as a result of changes in either temperature or humidity. THE REQUIRED TIME FOR THIS NEW ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer, IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. Alternate equivalent materials for this kit may be available from a local glass repair shop under the following product numbers: Other manufacturers of Urethane Adhesive that have documented their ability to meet or exceed General Motors specification # 3651M (Performance Requirements for Stationary Glass Bonding Adhesive System Service) are also considered to be equivalent to GM Kit (P/N 12346392). In previously published Corporate Bulletin Number 73-10-54, increasing customer demands for faster service have resulted in quicker two-part urethane adhesives to be made available. Essex Beta Seal U216* (two-part urethane adhesive) also meets the General Motors 3651M Specification and can be Page 1074 Coolant: Technical Service Bulletins Cooling System - Use of Recycled Engine Coolant Number: 91-235-6B Section: 6B Date: MARCH 1991 Corporate Bulletin No.: 116201 Subject: USE OF RECYCLED ENGINE COOLANT Model and Year: ALL PASSENGER CARS AND TRUCKS With the current emphasis on environmental issues and disposal of waste, significant attention is being given to the recycling of engine coolant. Many coolant recycling systems are being aggressively marketed today, ranging from very complex distillation (stationary) to straightforward filtration (mobile). As stated in previous service bulletins, General Motors does not endorse the use of recycled engine coolants in our products at this point in time. Recycling engine coolant is a very complex procedure and consequently will require a significant amount of research to determine which of the many processes is acceptable by General Motors. While we understand the growing concern being placed on (spent) engine coolant disposal, it is imperative that the quality of engine coolants being used in General Motors vehicles is not affected in any way. General Motors is addressing the issue of recycled engine coolants for the combined benefit of our dealers, vehicle owners, and the environment. Over the next several months General Motors will conduct an experiment designed to evaluate both distillation and "on-site" recycling processes. The results of this experiment will be provided to all dealers (spring, 1991) and will outline which process(es) is acceptable to General Motors. It is essential that recycled engine coolant not be used in any General Motors products as communicated in previous bulletins. Page 5391 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 431 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 7110 Page 8293 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 8349 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 1738 Rocker Arm Assembly: Adjustments VALVE ADJUSTMENT The VIN W engine does NOT have adjustable valve lash. When servicing the valve train requires removing and re-installing the rocker arms, tighten the rocker arm nuts to 27 Nm (20 ft. lbs.). Turbo Hydra-Matic 3L30 (180C) Fluid - A/T: Testing and Inspection Turbo Hydra-Matic 3L30 (180C) Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface and engine idling in Park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, if fluid level is too low, complete loss of drive may occur especially when cold, which can cause transmission failure. The oil should be drained, the oil pan removed, the screen cleaned and fresh fluid added every 30,000 miles for trucks under 8600 lbs. GVWR or every 24,000 miles for vehicles over 8600 GVWR. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or as a tow vehicle this maintenance should be performed every 15,000 miles for trucks under 8600 GVWR, or every 12,000 miles for trucks over 8600 GVWR. Page 4561 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 155 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Diagram Information and Instructions Vehicle Speed Sensor/Transducer - Cruise Control: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 4696 Brake Drum: Fundamentals and Basics Notes, Warnings, and Hints DRUM REMOVAL The drum should just slide off however it will often bind or stick for the following reasons: Excessive Grooves or Scoring - The interlocking grooves prevent the drum from sliding off. Uneven Wear - Uneven wear across the surface of the shoe creates a wedge which prevents the drum from sliding off. Lip or Edge - Commonly there will be a lip worn at the edge of the drum where the shoe to drum contact stops. NOTE: If both drums are stuck tightly, verify the parking brake is released. To remove a drum which is stuck you should retract the shoes by backing off the automatic adjuster. If the drum still will not slide off there may be corrosion between the drum and hub. A few sharp blows from a mallet or hammer along the front flat surface of the drum will usually free the drum. CAUTION: Prying off a stuck drum with a puller or pry bar can damage the springs or hardware. Always attempt to withdraw the shoes with the automatic adjuster first. Once the drum is removed a layer of brake dust will remain in the bottom of the drum. This dust should be thoroughly soaked with water or brake cleaner and then removed from the drum. WARNING: Inhaling brake dust is extremely hazardous to your health. DRUM INSTALLATION - Prior to installing the drum verify the automatic adjuster operates properly and that the tools you are intending to use to adjust the brakes will be able to reach the adjuster. - With the drum off, practice operating the adjuster through the access hole in the backing-plate. This will make adjusting the brakes much easier once the drum is installed. Ensure the shoes/linings are centered on the backing-plate (top to bottom and side to side). The drum will be very difficult to slide on if the shoes/linings are not centered. Symptom Charts Brake Lamp: Testing and Inspection Symptom Charts Stoplamps Do Not Operate Stoplamps Do Not Operate On One Side Page 5076 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 4277 Pinion Bearing: Adjustments Timken/Rockwell - 12 Inch Ring Gear Fig. 1 Timken/Rockwell drive axle w/12 inch ring gear exploded view DISASSEMBLY 1. Tap or press pinion from cage, taking care not to damage shaft threads, then remove outer pinion bearing, Fig. 1. 2. Remove spacer from pinion, then the inner bearing, using suitable separator and press or puller. 3. If straddle bearing must be replaced, remove snap ring and washer, then the bearing, using suitable puller. 4. If bearings are to be replaced, press outer races from bearing cage, taking care not to distort cage. 5. Inspect components as outlined, and replace as needed, keeping components in order for assembly. ASSEMBLY & PRELOAD ADJUSTMENT 1. When installing new cups, press them firmly against pinion bearing cage shoulders. 2. Lubricate bearings and cups with suitable lubricant. 3. Press rear thrust and radial bearings firmly against pinion shoulders, using suitable sleeve that will bear only on bearing inner race. 4. Install radial bearing lock ring, then squeeze ring into pinion shaft groove. 5. Insert pinion and bearing assembly in pinion cage and position spacer or spacer combination over pinion shaft. 6. Press front bearing firmly against spacer. Page 7218 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7531 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 5651 Fig. 1 Troubleshooting power steering system Page 1195 Refrigerant: Technical Service Bulletins A/C Refrigerant - Contamination File In Section: 1 - HVAC Bulletin No.: 43-12-23 Date: September, 1994 Subject: Contaminated A/C Refrigerant Models: 1994 and Prior Passenger Cars and Trucks with R12 Air Conditioning Systems Government regulations limit the production of R12 refrigerant, commonly referred to as Freon, during 1994/1995 and restrict manufacture of new R12 material effective January 1, 1996. As R12 prices rise and supplies are depleted, it is anticipated non-approved substitute refrigerants and/or poor quality R12 material sold as new or reprocessed may become more prevalent. The Mobile Air Conditioning Society (MACS) recently expressed concern over reports of the sale of R12 refrigerant containing as high as 15% contamination by R22, a refrigerant commonly used in stationary home systems but unsuitable for use in mobile units. GM dealers should be careful to protect against contaminating their existing supplies of R12 or the A/C systems in customers' vehicles they service by dealing with reputable suppliers. All R12 refrigerant purchased for warranty repairs should be purchased through GM SPO to ensure GM quality standards are met. The use of non-approved R12 refrigerant substitutes, some of which contain flammable materials, has also been reported by MACS. These products are available to "do-it-yourselfers" who, in many cases, believe they are harmless replacements for the small cans of R12 used so commonly in the past. Once added to the A/C system, the vehicle can no longer be serviced using R12 recovery/recycling equipment without: - Risking permanent damage to recovery/recycling equipment - Contaminating the previously recovered R12 material in the recovery tank - Spreading the contamination when the recovered material is used to charge other vehicles or - Possible loss of the recovered material if the contaminated level is high enough to activate the air purge system Contaminated refrigerant also impacts customer satisfaction through poor vehicle A/C performance and loss of A/C system compressor/component durability. System or component failure resulting from the use of refrigerant which does not meet GM specification is not covered by the "New Vehicle Warranty". Unfortunately, there is no simple method to identify if a "do-it-yourselfer" or repair shop has added to or recharged a system with a non-approved refrigerant. The inability to protect against the spread of contaminated refrigerant threatens the recycling program and the industry's desire to maximize use of the remaining R12 supply. Beginning in 1993, General Motors STG, Harrison Division, Research Labs and Kent-Moore worked in conjunction with suppliers of various technologies to develop a tester to identify contaminated refrigerant in vehicle A/C systems before recovery. During development of the technology, several dealer service manager focus group studies were conducted to identify design features to best suit dealership needs. The discussions and surveys clearly indicated the desire for a dedicated instrument, permanently mounted to the refrigerant recovery cart to ensure ALL vehicles are automatically tested prior to recovering refrigerant. Testing ALL refrigerant for contamination prior to recovery is the ONLY means to ensure customer satisfaction, protect recovery equipment and avoid unintentional venting of refrigerant by your dealership. General Motors has evaluated all available technology for this project and only the J 39851 R12 "Pureguard" meets General Motors' specifications. The J 39851 R12 Pureguard Refrigerant Monitor has been classified as an essential tool and will be shipped by Kent-Moore to your dealership beginning in September of 1994. The essential price of the R12 "Pureguard" is $561 (for Canadian dealers the price is $800 Canadian). If your dealership has multiple R12 recovery equipment, additional units may be ordered from Kent-Moore for $561 at 1-800-345-2233. Features of the R12 "Pureguard" include: - Universally mounts to R12 Recovery Equipment - Automatically interrupts power to the Recovery Equipment when contaminated refrigerant is identified - Fully automatic design does not require technician action, training or interpretation - LCD displays Pureguard functions Battery Voltage Signal Voltage Signal: Description and Operation Battery Voltage Signal PURPOSE Inform the control module that there is a basic battery voltage problem. OPERATION Battery/ignition voltage is an analog input signal read by the control module. The ignition switched battery voltage circuit is used for this diagnostics. If voltage is low, the control module can compensate for a weak spark delivered to the distributor by: Increaseing injector on time. - Increaseing idle RPM. - Increaseing ignition dwell time. Page 2764 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Page 2555 CMFI Intake Manifold Sensors/Valves Page 8467 Door Switch: Locations Door Jamb Switch, LH Rear In LH B-Pillar Locations Rearview Mirror Map Lamp Wiring Page 6976 8. Remove ashtray and any wires needed for clearance to remove radio trim plate. 9. Remove radio trim plate, then the nuts from the support clips, Fig. 25. 10. Remove support bracket retaining screws, then pull radio rearward and disconnect electrical connectors, antenna cable and speaker connectors. 11. Remove speaker grille attaching screws, then the speakers, Fig. 26. 12. Remove instrument panel attaching bolts and nuts, then pull panel rearward, disconnect all electrical connectors and remove panel. 13. Reverse procedure to install. Page 1265 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Page 1009 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 311 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 8117 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 310 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 5226 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: All Technical Service Bulletins Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 6213 Compressor Clutch Coil: Service and Repair With HR6-HE Compressor Remove or Disconnect 1. Perform Steps 1 through 4 of "Clutch Rotor and/or Bearings" removal procedure. Mark clutch coil terminal location on compressor front head. Clutch Coil Assembly Removal 2. Install J 33023-A puller pilot on front head of compressor. Also install J 8433-1 puller crossbar with J 33025 puller legs. 3. Tighten J 8433-3 forcing screw against the puller pilot to remove the clutch coil. Install or Connect 1. Place the clutch coil assembly on the front head with the terminals positioned at the "marked" location. 2. Place the J 33024 clutch coil installer over the internal opening of the clutch coil housing and align installer with the compressor front head. Page 4593 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 2705 Distributor: Description and Operation Distributor Reference Signal PURPOSE The distributor reference signal provides the control module with both engine RPM and crankshaft position information. This enables the control module to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the control module receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the control module will not operate the injector. Coolant Temperature Sensor Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Sensor HP Engine RH Front Side Of Engine. Front Of Engine Applicable to: 4.3L/V6-262 HP Engine Diagram Information and Instructions Cruise Controller: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 161 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 1332 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 6853 Front Door Window Glass: Technical Service Bulletins Body - Side Window Chipping Information INFORMATION Bulletin No.: 06-08-64-001B Date: October 20, 2009 Subject: Information on Side Door Window Glass Chipping Caused by Hanging Vehicle Key Lock Box Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add vehicles and model years and to include all types of door window glass. Please discard Corporate Bulletin Number 06-08-64-001A (Section 08 - Body & Accessories). - In several warranty parts review cases, side door window glass was observed with a chip or chips on the top side of the window glass. Dealer contacts confirmed that they use a vehicle key lock box on the front side door window glass. - A random selection of side door glass returns will be conducted to confirm adherence. If a side door glass is discovered with a chip or chips in the location previously described, the side door glass will be returned to the dealership for debit. Example of Side Door Glass - DO NOT place a vehicle key lock box on a side door window glass. Page 5122 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 7602 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 6299 Control Assembly: Description and Operation Circuit Operation BLOWER CONTROLS In all blower speeds except HI, the HTR-A/C Fuse supplies voltage to the Blower Motor through the A/C-Heater Selector Switch. In High Speed operation, voltage from the Blower Switch energizes the High Blower Relay, permitting voltage to flow from the Battery Junction Block to the Blower Motor. BLOWER LOW SPEED OPERATION With the Blower Switch in LO, voltage flows from the A/C-Heater Selector Switch through the BRN (64) wire, the Blower Switch and TAN (63) wire to the Blower Resistors. The voltage then flows through all three resistors and the normally closed contacts of the High Blower Relay to the Blower Motor causing the Blower Motor to run at Low speed. BLOWER MEDIUM SPEED OPERATION With the Blower Switch in MED, voltage flows from the A/C-Heater Selector Switch through the BRN (64) wire to the Blower Switch and the LT BLU (72) to the Blower Resistors. The voltage then flows through two of the resistors and the normally closed contacts of the High Blower Relay to the Blower Motor causing the Blower Motor to run at Medium speed. BLOWER HIGH SPEED OPERATION With the Blower Switch in Hi, voltage flows from the A/C Heater Selector Switch through the BRN (64) wire to the Blower Switch and bypasses the Blower Resistors and flows to the High Blower Relay through the ORN (52) wire. This voltage energizes the relay and closes the normally open contacts of the relay. Voltage then flows from the Battery Junction Block, through the relay to the Blower Motor causing the Blower Motor to run at High speed. Page 3115 EGR Valve: Description and Operation Exhaust Gas Flow NOTE The linear EGR valve is used on all 4.3L VIN W engines. The linear EGR valve is also used on all 4.3L VIN Z engines with California emissions and automatic transmision. For 4.3L VIN Z engines without California emissions, refer to Negative Backpressure EGR Valve. PURPOSE The Exhaust Gas Recirculation (EGR) system is designed to lower NOx (oxides of nitrogen) emission levels created by high combustion temperatures. The Linear EGR valve is operated exclusively by Control Module command. To effectively operate the Linear EGR valve the control module monitors various engine parameters: Throttle Position Sensor (TPS). - Manifold Absolute Pressure (MAP). - Coolant Temperature Sensor (TPS). - Pintle Position Sensor (PPS). Output messages are then sent to the EGR system indicating the proper amount of exhaust gas recirculation necessary to lower combustion temperatures. This electronic metering of exhaust gas is ten times faster than vacuum operated models and offers improved diagnostic capabilities as well. Specifications Engine Oil Pressure: Specifications Vin Z, W, Oil Pressures Vin Z, W, Oil Pressures Normal Oil Pressure Minimum Pressures 6 psi at 1000 rpm 18 psi at 2000 rpm 24 psi at 4000 rpm Page 7336 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 2542 Oxygen Sensor Location Page 7269 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 6641 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 4969 Battery Cable: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 2020 needle bearing of the balance shaft. 4. To eliminate the possibility of the rear needle bearing rattling, a production running change was made in early May 1992, to a different type bearing. The needle bearing was changed to a journal type sleeve bearing (much like a camshaft bearing). This type bearing requires pressure fed oil, therefore, an engine block casting change was made to allow an oil passage to be drilled from the vertical oil gallery coming from the oil filter to the rear balance shaft journal. 5. If the detonation type rattle noise is unacceptable to the customer, the engine must be replaced using an SPO Goodwrench engine assembly part number 12520408. Important: Dealers are to retain all parts replaced for inspection in accordance with GM Service Policy and Procedures section 1.7.4 - Disposition of Defective material. Important: Replaced engine blocks are NOT to be provided to engine rebuilders. They should be returned as per instructions shipped with the replacement engine. 6. MEM-CAL information: When replacing a 1992 needle bearing engine (only produced prior to the May 1992 VIN break-points) with a sleeve bearing engine, the MEM-CAL must be updated to the later 1992 version. See part number information below. These new MEM-CALs are required to change the ESC calibration for the sleeve bearing engine. Without the correct calibration MEM-CAL, the engine will detonate. 7. ESO (Electronic Spark Control) information: The sleeve bearing engine "sounds" different to the ESO system. To make the sleeve bearing engine operate properly the 1992 M and L van vehicles, the knock sensors and locations have been changed. The 1992 M/L motors require only one 3900 ohm knock sensor mounted in the transmission flange close to the distributor. Connect the knock sensor harness to the knock sensor in the transmission flange. The second knock sensor connector harness at the middle of the right cylinder head will not be used on the 1992 model year M and L vans with the sleeve bearing engines. To ensure the harness does not lie on the exhaust manifold and short out, tie the connector back onto the harness using a plastic tie strap. The S and T trucks will continue using both 8200 ohm knock sensors with the sleeve bearing engine. No modification to the existing harness is necessary. Sleeve Bearing Balance Shaft Knock Sensor Information VIN Breakpoints for Sleeve Bearing Engines Beginning with: Locations Vacuum Vent Valve: Locations Cruise Control Components, Near Steering Column. behind the left hand side of the I/P. Page 2963 Oxygen Sensor: Technical Service Bulletins Engine Controls - Heated Oxygen Sensor Diagnosis Group Ref.: Engine Fuel & Emission Bulletin No.: 366501 Date: November, 1993 INFORMATION SUBJECT: HEATED OXYGEN SENSOR DIAGNOSIS MODELS: 1992-93 CHEVROLET & GMC LIGHT DUTY TRUCKS WITH 4.3L (LB4/L35), 5.0L (L03) AND 5.7L (L05) ENGINES 1992-93 OLDSMOBILE BRAVADA Some heated oxygen sensors are being replaced in error due to low reference voltage. REFERENCING SERVICE MANUAL Before diagnosing any heated oxygen sensor, be sure to follow the appropriate service manual diagnostics. The fault tree selected is dependent upon which control module system is on the vehicle. DIAGNOSTIC INFORMATION The electronic control module (ECM) normally applies a reference voltage of approximately 450mv to the oxygen sensor. When the ignition is turned "on", the heating element inside the oxygen sensor will immediately start heating the sensor element. The oxygen sensor will become fully functional in 15 to 90 seconds. Because the engine is not running, the gases around the oxygen sensor in the exhaust stream will be mostly ambient air. The high amount of oxygen in the exhaust stream will be interpreted as a lean exhaust and the 450mv reference voltage from the ECM will be pulled low. The oxygen sensor voltage should drop from 450mv to less than 100mv within 90 seconds. Therefore, the oxygen sensor is performing normally. LOW REFERENCE VOLTAGE (This test must be completed within 10 seconds after key up.) If your Tech 1 initial reference voltage is low (less than 300mv), you may have a shorted oxygen sensor. Turn the ignition "off"; allow the sensor to cool for ten minutes and retest. If the voltage is still low, disconnect the oxygen sensor and see if your Tech I now indicates approximately 450mv reference voltage. If so, change the oxygen sensor. HIGH REFERENCE VOLTAGE If your Tech 1 initial reference voltage is high (greater than 600mv), you may have a sensor signal that is shorted to heater voltage. This may cause a code 45. Allow sensor to cool ten minutes and retest. If voltage still remains high, disconnect oxygen sensor. If reference voltage still remains high, you may have a short to voltage in the engine harness or an ECM problem. If you disconnect the oxygen sensor and reference voltage returns to approximately 450mv, replace the internally shorted oxygen sensor. CALPAK PROM - Programmable Read Only Memory: Description and Operation CALPAK CAUTION: If the computer is found to be defective and needs replacement, remove the old CALPAK and PROM, then place both into the replacement computer. When replacing the COMPUTER always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: The resistor network calibration called a CALPAK is located inside the computer. Its appearance and service is similar to the PROM. The CALPAK allows fuel to be delivered if other parts of the computer fail. The CALPAK provides the computer with calibrations for: ^ Cold Start Cranking. ^ Limp home fuel (fuel backup mode). Page 547 Brake Light Switch: Adjustments Fig. 2 Stop Light Switch Installation 1. Disconnect battery ground cable. 2. Disconnect wiring connector from brake light switch located on brake pedal bracket. 3. Pull switch from mounting bracket. 4. Depress brake pedal, then push new switch into clip until shoulder bottoms out, Fig. 2. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed .53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Page 6649 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Campaign - 02-313 Stop Delivery Notice Update Fuel Level Sensor: Recalls Campaign - 02-313 Stop Delivery Notice Update ** ADMINISTRATIVE MESSAGE 01-277 CREATED ON 9/5/91 AT PAGE 1 OF 1 TO: ALL CHEVROLET DEALERS SUBJECT: STOP DELIVERY NOTICE 1992 S/T TRUCKS THIS IS WITH FURTHER REFERENCE TO THE 1992 S/T TRUCK STOP DELIVERY DCS ADMIN MESSAGE 01-258 DATED 8/22/91 SENT TO ALL CHEVROLET DEALERS. SELECT DEALERS WERE ADVISED IN DCS MESSAGE 02-313 DATED 9/5/91 OF PRODUCT CAMPAIGN 92C02 FUEL LEVER SENDER ARM/TANK INTERFERENCE. THIS DCS INCLUDED INVOLVED DEALER CODES AND INVOLVED VIN'S. ANY DEALER NOT RECEIVING DCS ADMIN MESSAGE 02-313 HAS NO INVOLVED VEHICLES ASSIGNED AND VIN'S WHICH FALL WITHIN THE ORIGINAL VIN RANGES LISTED BELOW ARE RELEASED FROM THE STOP DELIVERY. ASSEMBLY PLANT STARTING VIN ENDING VIN PONTIAC WEST N0100014 N0101228 MORAINE N2100052 N2101700 SHREVEPORT N8100014 N8101560 PLEASE COMMUNICATE THIS INFORMATION TO ALL DEALERSHIP MANAGEMENT IMMEDIATELY UPON RECEIPT. ABS - Brake Bleeding Procedure Technical Service Bulletin # 931985 Date: 930501 ABS - Brake Bleeding Procedure Number: 93-198-5 Section: 5 Date: MAY 1993 Corporate Bulletin No.: 365003 ASE No.: A5 Subject: REVISED 4WAL BRAKE SYSTEM BLEEDING PROCEDURE Model and Year: 1990-93 M/L, S/T 1992-93 C/K 1993 G MODELS WITH 4WAL SERVICE UPDATE Bulletin Description THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-74-5 DATED OCTOBER 1990 TO UPDATE THE BLEED PROCEDURE AND TO ADD MODELS SINCE EQUIPPED WITH 4WAL BRAKE SYSTEMS. ALL COPIES OF 91-74-5 SHOULD BE DISCARDED. THIS BULLETIN ALSO UPDATES INFORMATION IN 1993 M/L SERVICE MANUAL, 1993 S/T SERVICE MANUAL, 1993 C/K SERVICE MANUAL, 1993 G SERVICE MANUAL, AND STG RWAL/4WAL 1988-1991 APPLICATIONS MANUAL 15005.05 (VERSIONS 2 TO 5). PLEASE PLACE A COPY OF THIS BULLETIN IN EACH MANUAL. THIS BULLETIN IS EQUIVALENT TO SERVICE MANUAL UPDATE BULLETIN 93-12-5, DATED SEPT. 1992. This 4WAL brake system bleed procedure is the most efficient bleed procedure to date. The 4WAL Brake Pressure Modulator Valve (BPMV), formerly called Electro Hydraulic Control Unit (EHCU), should be bled after replacement or if air is suspected to be trapped inside the unit. There are two conventional methods to use when bleeding the 4WAL BPMV: (1.) Pressure Bleeding or (2.) Manual Bleeding. IMPORTANT: There are two internal bleed screws (brass colored), one on each side of the BPMV, that open internal channels. Open the internal bleed screws 1/4 to 1/2 turn before bleeding (figure 2). New 4WAL BPMV's are shipped with the internal bleed screws open, so first close the internal bleed screws until snug, then open 1/4 to 1/2 turn. NOTICE: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Clean any fluid that may drip onto wheel cylinders or calipers to prevent corrosion. Always re-seal and wipe off brake fluid containers to prevent spills. Tools Required Page 8532 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Compact Disc Players - CD Changer Loading Procedures Compact Disc Player (CD): Customer Interest Compact Disc Players - CD Changer Loading Procedures File In Section: 9 - Accessories Bulletin No.: 64-96-01 Date: January, 1997 INFORMATION Subject: Compact Disc Players - Procedures for Correct Use and Maintenance Models: 1997 and Prior Passenger Cars and Trucks CD Changer Loading Procedures Because of differences in CD changer loading procedures, some confusion exists regarding this issue. Although correct loading procedures are included with each changer's Owner's Manual, often this information is not available to the dealer service personnel. Verify proper loading when evaluating customer concerns of "CD inoperative". Delco Electronics Product Type Loading Procedure Radio w/intergral CD label side up 6 disc changer (LLAI) label side up 10 disc changer (FMI) label side up 12 disc changer (LLAI) label side down Important: Failure to load magazine/player correctly will disable the operation. Important: Only the 12 disc changer is to be loaded with the label side down. CD Cleaners Avoid use of commercially available CD cleaners. The use of CD cleaners is not recommended and can damage the player's CD mechanism. Page 8294 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 8542 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 6591 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 7847 Use applicable labor time guide for labor hours. Page 8023 Use applicable labor time guide for labor hours. Specifications Brake Caliper: Specifications Caliper Mounting Bolt 37 ft.lb Page 1296 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Nippon Seiko Recirculating Ball Gear Steering Gear: Adjustments Nippon Seiko Recirculating Ball Gear Fig. 2 Pitman Arm Alignment Fig. 3 Adjusting Worm Shaft Starting Torque 1. Ensure worm shaft is free from thrust play. 2. Position pitman arm 11 degrees from the parallel to the worm shaft, Fig. 2. Front wheels should be in the straight ahead position. 3. Measure shaft starting torque with front wheels straight ahead, using pinion socket J-34871-A or equivalent and a torque wrench, Fig. 3. Torque should be 5-8 inch lbs., if not within range adjust as necessary. 4. Check worm shaft operating torque. Torque should be 12 inch lbs. 5. If torque is not as specified, adjust worm shaft starting torque, then recheck operating torque. 6. If specifications are not obtained after adjustment, replace gear box. Page 5767 Wheel Bearing: Service and Repair REAR WHEEL BEARINGS AND/OR HUB Fig. 2 Axle Shaft Bearing Removal Fig. 3 Axle Shaft Bearing Installation Fig. 4 Axle Shaft Seal Installation 1. Remove axle shaft as described under AXLE SHAFT. 2. Remove axle seal by prying behind seal steel case with a pry bar. Use caution to avoid damaging axle housing. 3. Using a puller and slide hammer, remove axle bearing, Fig. 2. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer No. tool J-23765, or equivalent, until bearing is seated in housing, Fig. 3. 5. Lubricate seal lips with gear lubricant, then position seal on axle shaft seal installer tool No. J-23771 or equivalent, and install in axle housing, tapping into place until seal is flush with axle housing, Fig. 4. 6. Reinstall axle shaft. Specifications Output Shaft: Specifications Output Shaft Thrust Ring ..................................................................................................................... ................................................................... 12 ft. lbs. Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 7422 Brake Vacuum Release Valve: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Campaign - Interior Front Door Handles Technical Service Bulletin # 06027A Date: 070523 Campaign - Interior Front Door Handles Bulletin No.: 06027A Date: May 23, 2007 SPECIAL COVERAGE Subject: 06027A - SPECIAL COVERAGE ADJUSTMENT - CLASS ACTION SETTLEMENT - INTERIOR DOOR HANDLE SPRING BREAKAGE Models: 1982-1994 CHEVROLET S/T PICKUP AND UTILITY 1982-1994 GMC S/T PICKUP AND UTILITY, JIMMY 1991-1994 OLDSMOBILE BRAVADA INVOLVED IN SOUTH CAROLINA CLASS ACTION SETTLEMENT Supercede: The expiration date for this special coverage has been extended to December 31, 2007. The mailing of letters to customers was delayed. Letters will be mailed to customers on May 30, 2007. Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Condition Some customers of 1982-1994 Chevrolet S/T pickup and utility vehicles; 1982-1994 GMC S/T pickup and utility vehicles; and 1991-1994 Oldsmobile Bravada vehicles are entitled to the benefits of a class action settlement. The benefits are listed below and customers will be provided with a letter to present to dealers that details the remedy that they chose. Special Coverage Adjustment This special coverage covers the conditions described below until December 31, 2007. Customers may have any combination of the benefits listed below. Please see the customer's letter to determine the appropriate remedy. Reimbursement - Customers who have replaced an interior front door handle assembly have already submitted a request for reimbursement. GM is handling the reimbursements. There is no action required from the dealer. Replacement of broken interior front door handle assembly(s) - Some customers have chosen to receive a replacement interior front door handle assembly(s). Dealers are to provide the customer with the assembly(s) at no charge. The customer is to self-install or pay the dealer for the installation of the assembly(s). Application of lithium grease - Customers who have the original front door handle assembly(s) in which the spring is not broken, are entitled to have the spring(s) greased. Dealers are to apply lithium grease to the unbroken spring(s) of the original front door handle assembly(s) at no charge. Vehicles Involved Customers involved will present the dealer their vehicle with a letter that authorizes the repair. If the customer requests a new interior front door handle, dealer must verify it replaces a broken interior front door handle assembly. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 6666 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 3591 Knock Sensor: Description and Operation Electronic Spark Control Circuit Knock Sensor (KS) Sensor PURPOSE Varying octane levels in today's gasoline can cause detonation (also known as spark knock) in an engine. The Knock Sensor (KS) system has various knock sensors that are used on all engines except the 2.5L. The KS system reduces spark knock (detonation) in the engine. This allows the engine to have a maximum spark advance for improved driveablity and fuel economy. CONSTRUCTION This KS system has three main components: - KS Module. - Knock sensor - ECM OPERATION The knock sensor detects abnormal vibration (spark knocking) in the engine. The knock sensor is mounted in the engine block near the cylinders. The KS module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the Ignition Control (IC) to reduce spark knocking. The KS module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the knock sensor. This allows the ECM to maintain maximum timing advance under various engine load conditions. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards IC to reduce spark knock. Page 4344 thrust washers. Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and place jackstands under frame side rails. Support axle housing with a suitable jack. 2. Drain lubricant from axle housing and remove propeller shaft. 3. Remove wheel and brake drum. 4. Disconnect parking brake cable from lever and at brake flange plate. 5. Disconnect hydraulic brake lines from connector and lower shock mounting from axle brackets. 6. Remove vent hose from axle vent fitting if equipped. 7. Disconnect height-sensing and brake proportioning valve linkage if equipped. 8. Support assembly with a hydraulic jack and remove rear stabilizer bar. 9. Remove U-bolts, spring plates and spacers from axle assembly. 10. Lower jack and axle assembly. 11. Reverse procedure to install. Door Jamb Switch Door Switch: Locations Door Jamb Switch On A-Pillars Page 6662 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 3715 1992 LB4 VIN Z For vehicles with "cold knock" only. For vehicles with "cold knock" having previously installed detonation field fix PROM - OR For vehicles with "cold knock" and detonation For 1991-93 model year L05 and L19, 1991 and 1993 LB4 engines, two actions have been found to show a high probability of success incuring short duration cold knock (Category A). General Motors suggests performing the following steps. NOTE: These steps are only applicable to short duration cold knock, and will not eliminate a knock occurring under load. Neither will these actions eliminate a knock lasting more than 10 seconds, nor a knock occurring in a hot or warm engine. Step 1: Install a check valve oil filter Original Filter Install PF35 AC PF1218 PF51 AC PF52 Step 2: Change the oil; use a synthetic oil meeting the API Service SG or SG/CE standard. NOTE: This action is only required once; conventional (non-synthetic) API Service SG or SG/CE oil may be reinstalled at the next oil change. If an LB4 (VIN Z 4.3L V6) or an L05 (VIN K 5.7L V8) continues to exhibit short duration cold knock after performing steps one and two and Page 842 Rear Door Power Window Page 6898 Trailer Adapter Kit: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Wheels - Finish Damage During Off Car Balancing Wheels: All Technical Service Bulletins Wheels - Finish Damage During Off Car Balancing BULLETIN NUMBER: 93-3E-67 SECTION: 3E Wheels & Tires NUMBER: 3 CORPORATE REFERENCE NUMBER: 3935O2R DATE: June 1993 SUBJECT: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING MODELS: 1985-93 MODELS WITH ALUMINUM WHEELS Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car vehicle balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make Page 5602 SERVICE PARTS INFORMATION Windshield/A Pillar - Pop Noise Diagnosis Dashboard / Instrument Panel: Customer Interest Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Tires (Front) - Irregular Wear Tires: Customer Interest Tires (Front) - Irregular Wear Number: 91-26-3E Section: 3E Date: June 1990 Corp. Bulletin No: 053501 Subject: FRONT TIRE WEAR Model and Year: 1982-91 LIGHT DUTY TRUCKS (REAR WHEEL DRIVE) THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-12-3E. THE KILOMETERS HAVE BEEN TRANSLATED INTO MILES. ALL COPIES OF 91-12-3E SHOULD BE DISCARDED. Rear wheel drive trucks, equipped with All Season and/or On-Off road tires may exhibit irregular wear of; the front tires. Small amounts of irregular wear is considered normal and is not necessarily a result of incorrect alignment. Incorrect alignment (especially toe) may result in premature wear of the front tires, however agressive cornering may also have a similar effect. Drive axle tires are much less prone to irregular wear, therefore they should not be considered for comparison of wear to non-drive axle tires. The rate of irregular wear is also dependent upon the depth of tread. New tires are more prone to irregular wear, so it is essential that tires are rotated at the proper intervals to normalize the wear. Page 895 Disclaimer Specifications Ignition Coil: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ......................................................................................................................................................... 24 to 40 N-m (25 to 30 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Page 6138 Removing The Pulley Retainer Ring 2. Pulley bearing retainer (2) with J 6435. 3. Pulley (6). Removing The Pulley And Bearing - Install J 9395 over the end of the compressor shaft (38). Important Use J 9395 puller pilot to prevent internal damage to the compressor when removing the pulley. Do not use the pulley directly against the end of the shaft. - Place J 8433 over J 9395 for the regular V-groove pulley. - Place J 24092 over J 9395 for the multi-groove pulley. - Turn the screw on J 8433 to remove the pulley (6). Important When using J 24092, the puller arms must extend around to the rear side of the pulley. Do not attempt to pull the pulley off by engaging the puller arms in a multi-groove pulley. Page 4787 Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Specifications Blower Motor: Specifications Blower Motor Mounting Screw ............................................................................................................. ................................................... 2 Nm (18 in. lb.). Blower Motor Resistor Mounting Screw .................................................................................................................................................. 2 Nm (18 in. lb.). Blower Motor Case Screw ................................................................................................................... ..................................................... 3 Nm (27 in. lb.). Blower Motor Case Nut ....................................................................................................................... ..................................................... 3 Nm (27 in. lb.). Page 6274 1. Condenser (4). Refer to A/C System Oil Charge Replenishing / "Refrigerant Oil Distribution" if replacing condenser. See: Service and Repair 2. Upper insulators (16). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 3. Retainers (17) and bolts (18). - Tighten bolts (18) to 1.4 Nm (12 in. lb.). 4. Evaporator tube (5) to condenser (4). 5. Refrigerant hose (3) to condenser (4). Tighten - Refrigerant hose (3) to 24 Nm (18 ft. lb.). - Evaporator tube (5) to 17 Nm (13 ft. lb.). 6. Radiator. 7. Upper fan shroud. 8. Refrigerant to the system. - Check the system for leaks. Service and Repair Seals and Gaskets: Service and Repair Fig. 3 Axle Shaft Bearing Removal Fig. 4 Axle Shaft Bearing Installation Fig. 5 Axle Shaft Seal Installation 1. Remove axle shaft as described under AXLE SHAFT. 2. Remove axle seal by prying behind seal steel case with a suitable pry bar. Use care to avoid damaging axle housing. 3. Remove axle bearing using slide hammer J-2619, adapter J-2619-4, or axle bearing puller J-22813-01. The tangs of the axle bearing puller should engage the bearing outer race, Fig. 3. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer J-23765 or equivalent until bearing is seated in housing, Fig. 4. 5. Apply suitable gear lubricant to seal lips, then position seal on axle shaft seal installer J-23771 or equivalent. Install in axle housing, tapping into place until seal is flush with housing, Fig. 5. Page 2514 Rear Of Engine Locations Steering Column Page 3117 Electrical Connector - With Tier 1 Emissions CONSTRUCTION Positioned at the top of the Linear EGR assembly are 5 terminals: 1. A is the pulse width modulated negative signal from the PCM. 2. E is the positive from the ignition. 3. B, C and D are terminals from the control module for the integral pintle position sensor. a. B is sensor ground. b. C is sensor output. c. D is +5 volts supply. EGR Valve Subassemblies OPERATION The solenoid (bobbin and coil) assembly is energized by 12 volt current which enters the valve through an electrical connector (terminal E), then flows through the solenoid assembly to the PCM and creates and electromagnetic field. This Field causes the armature assembly to be pulled upward, lifting the pintle a variable amount off the base. The exhaust gas then flows from the exhaust manifold (through the orifice) to the intake manifold. The height of the pintle is read by the pintle position sensor, and the PCM closes the loop on desired position versus actual position read, changing the pulse width modulated command to the solenoid accordingly, until the actual pintle position equals the desired pintle position. This results in improved flow accuracy. In most EGR designs, the flow is "OPEN LOOP", in which the system has NO feedback mechanism to monitor actual flow and then correct it. The Linear EGR valve is unique in that the control module continuously monitors pintle height and continuously corrects it in order to obtain accurate flow, making Linear EGR a " CLOSED LOOP" system. When the solenoid is de-energized (PCM breaks the circuit), the pintle is seated against the orifice, blocking exhaust flow to the intake manifold. Page 7594 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 2545 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION - Connectors and wires - Housing and insulator for cracks/damage - Sensor tip for silicone contamination (white powdery coating) CAUTION Do NOT perform the following test for more than 2 minutes, as this may cause damage to the catalytic converter. PERFORMANCE TEST Checks working range and response (speed). Warm engine - Install DVOM between sensor and ground (2 volt D.C. range) - "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). - Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. - Drive system lean: Create a vacuum leak from a source that is not an control module input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE After each test the O2 sensor should return to normal operating range within two to three seconds. - O2 Sensor should be replaced for failure to pass any of the tests above. NOTE A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. - Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. HEATING ELEMENT (H20S only) - Turn ignition "OFF". Disconnect electrical connector. - Connect test light between harness terminals "A" and "B". - Turn ignition "ON". Test light should be "ON". If test light is "OFF", connect test light to harness terminal "A" to ground. Light should be "ON" ensuring power circuit is operating correctly. - Turn ignition "OFF". - Using an ohmmeter, measure resistance between terminals A and B. Resistance @ Specified Temperature 3.5 ohms @ 20°C (68°F) 14 ohms @ 350°C (662°F) Page 7715 Symbol Identification Page 6698 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Locations RH Door Harness (LH Typical) Page 5714 Control Arm Bushing: Service and Repair Lower Control Arm & Bushing 4X2 Fig. 7 Lower Control Arm Front Bushing Removal. 4 X 2 Models Fig. 8 Lower Control Arm Rear Bushing Removal. 4 X 2 Models Fig. 9 Lower Control Arm Front Bushing Installation. 4 X 2 Models Fig. 10 Flaring Lower Control Arm Front Bushing. 4 X 2 Models Locations Engine Vacuum Line Routing Rear Side Marker Lamp: Description and Operation Rear Voltage is supplied through the CRANK Fuse to the Light Switch at all times. With Light Switch in PARK or HEAD, voltage is supplied to the Tail, Marker, Endgate, Clearance and License Lamps. Page 7359 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 5740 Page 6680 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 5044 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 546 LH I/P Harness Wiring Locations LH I/P Harness Wiring Footnotes 1 Thru 50 PROM - Programmable Read Only Memory: Application and ID Footnotes 1 Thru 50 [1] Also needs EGR P/N 1706739. [2] Also requires EGR P/N 17111295. [3] Requires Throttle Body service P/N 17067142, EGR valve service P/N 17067111, Injector service kit P/N 17067976. [4] Requires Throttle Body service P/N 17067142, EGR valve service P/N 17067107, Injector service kit P/N 17067976. [5] Requires Throttle Body service P/N 17067144, EGR valve service P/N 17067110, Injector service kit P/N 17067976. [6] PROM I.D. 7080 KJ is also acceptable for PROM I.D. 5853 KJ only. Requires Throttle Body service P/N 17067144, EGR valve service P/N 17067108 (FED), 17067144 (CAL), Injector service kit P/N 17067976. [7] Required Throttle Body service P/N 17067142, EGR valve service P/N 17067107 (FED), 17068210 (CAL), Injector service kit P/N 17067976. [8] Requires Throttle Body service P/N 17068019, EGR valve service P/N 17067109, Injector service kit P/N 17067976. [9] For Federal - Use 01226047 (PROM CODE 7654 BKW). For California - Use 01226049 (PROM CODE 7665 BKY). [10] For Federal - Use 01226054. For California - Use 01226056 [11] For Federal - Use 01226055. For California - Use 01226057. [12] For Federal - Use 01226046 (PROM CODE 7648 BKU). For California - Use 01226049 (PROM CODE 7665 BKY). [13] For federal - Use 01226046 (PROM CODE 7648 BKU). For California - Use 01226048 (PROM CODE 7659 BKX). [14] ECM may have been replaced by service ECM P/N 16019710 (1225500). [15] ECM may also be 16018161. ECM may also have been replaced by service ECM P/N 16018000 (1225330). [16] ECM may also be 16018201. ECM may also have been replaced by service ECM P/N 16018000 (1225330). [17] ECM may also be 16018211. ECM may have been replaced by service ECM P/N 16018000 (1225330). [18] ECM may also be 16023761. ECM may have been replaced by service ECM P/N 16018000 (1225330). [19] ECM may also be 16018101. ECM may have been replaced by service ECM P/N 16018000 (1225330). [20] For 2-board ECM only. [21] May need EGR valve P/N 17079563. Original equipment P/N 16029014. [22] Original equipment PROM P/N 16017094, now 16025254 [23] Original equipment PROM P/N 16017224, now 16025264. [24] Also needs EGR valve P/N 17079013. Original equipment PROM P/N 16030034 (PROM ID: BOH). [25] Requires kit P/N 25522748 containing: Wiring harness jumper P/N 12043500, Relay P/N 25522747, Foam P/N 25522723, EGR P/N 17079799. [26] Needs EGR valve P/N 17079818. [27] For (MY7) - Use 01226473 (SCAN I.D. = 3941). For (M19) - Use 01226474 (SCAN I.D. = 3951). [28] For (MY7) or (M19, C60) - Use 01226473 (SCAN I.D. = 3941). For (M19) - Use 01226474 (SCAN I.D. = 3951). [29] ECM may also be 16023561(M5), or 16033061(M4 with A/C). [30] For F62 axle - Use 01226441 (SCAN I.D. = 3622). For F17 axle - Use 01226439 (SCAN I.D. = 3332). [31] For one_board ECM only. Page 3725 PROM - Programmable Read Only Memory: Application and ID PROM/MEMCAL Identification Marks File In Section: 6E - Engine Fuel & Emission Bulletin No.: 44-65-01 Date: October, 1994 Subject: New PROM/MEMCAL Identification Markings Models: 1995 and Prior Passenger Cars and Trucks Note: For the purposes of this document, the terms PROM and MEMCAL will be used interchangeably. To simplify identification of service PROMs. a new external marking format will be implemented. Parts manufactured after Sept. 1994 will feature these new markings. This change will place the full 8-digit service part number on the PROM, in place of the old 4-digit "EXTERNAL ID" number. In the past, parts and service personnel could not identify a PROM without using a cross-reference table that matched external IDs and service numbers. In the future, the cross-reference table will not be required for PROMs; parts will be ordered directly from the number appearing on the PROM. However, the label will retain the broadcast code alpha characters to allow continued use of cross-reference charts, if so desired. Old Marking Format: New Marking Format: ^ Ordering the above PROM from the old marking format would require using a cross-reference chart to determine a service part number, based on the BROAD CAST CODE and EXTERNAL ID NUMBERS. ^ To order from the new format, simply combine the 2nd and 3rd lines to form an 8-digit part number that can be directly ordered from SPO (number 16134624 in the above example). As these changes are phased into the parts inventory, it should be noted that dealers will continue to see parts with both formats for some time in the future. This is because: ^ Millions of vehicles have already been built with the old format. ^ SPO has existing stock of MEMCALs and PROMs with the old format. ^ PROMS with 7-digit part numbers (representing less than 10% of current part numbers) will continue to use the old format. The 7-digit part numbers are easily identified because they always begin with "122xxxx". Due to manufacturing processes, more than one 8-digit part number may appear on a MEMCAL. In this event, service personnel should use the label on the exterior cover of the MEMCAL assembly. To avoid confusion, only the service label will include the BROAD CAST CODE, consisting of letter characters (I.E., ARCL). A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: Customer Interest A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Page 152 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 625 Intake Air Temperature Sensor: Description and Operation Intake Air Temperature Sensor PURPOSE The Intake Air Temperature (IAT) sensor is a thermistor and converts the resistance of the sensor to degrees. IAT is used by the control module to adjust fuel delivery and spark timing according to oncoming air density. OPERATION The control module applies a voltage (4-6 volts) signal to the IAT sensor through a resistor within the PCM and measures the voltage. By measuring the voltage, the PCM can determine IAT. Low intake air temperature produces high resistance (100,000 ohms at -40°C/-40°F) and high voltage. High intake air temperature produces a low resistance (70 ohms at 130°C/266°F) and low voltage. Page 5648 Steering Gear: Description and Operation Saginaw Recirculating Ball Gear Manual Steering Fig. 1 Cross-Sectional View Of Steering Gear The Saginaw steering gear, Fig. 1, is a recirculating ball nut and worm type. The ball nut is mounted on the worm, located on the lower end of the steering shaft. The steel balls act as a rolling thread between the worm and nut to provide low friction drive between them. Teeth on the ball nut engage teeth on the pitman shaft sector. The teeth on the ball nut are made so that a tighter fit exists between the ball nut and pitman shaft sector teeth when the front wheels are in the straight ahead position. The pitman shaft sector teeth are slightly tapered so that a proper preload may be obtained by moving the pitman shaft endways by means of a preload adjuster screw which extends through the gear housing side cover. The head of the preload adjuster and a selectively fitted shim fit snugly into a T-slot in the end of the pitman shaft, so that the screw also controls the end play of the shaft. When the wheel and steering shaft turn to the left, the ball nut is moved downward by the balls which roll between the worm and nut. As the balls reach the outer surface of the nut, they enter the return guides which direct them across and down into the ball nut where they enter the circuit again.When a right turn is made, the ball nut moves upward and the balls circulate in the reverse direction. Recall 99V193000: ABS 4WD Switch Defective 4WD Switch: All Technical Service Bulletins Recall 99V193000: ABS 4WD Switch Defective Description: Certain 4-wheel drive pickup trucks and sport utility vehicles equipped with ABS (antilock braking system) manufactured from September 1989 through August 1996. Under certain driving conditions the switch which signals the ABS system whether the vehicle is in 2-wheel or 4-wheel drive can malfunction causing increased stopping distances during ABS stops while in the two-wheel drive mode. If this occurred at a time when minimum stopping distance was required, a vehicle crash could occur without prior warning. Dealers will replace or repair the 4-wheel/2-wheel drive switch. The first phase of owner notification letters began May 31, 2000, with the last mailing completed by October 2000. Owners can contact Chevrolet at 1-800-222-1020 or GMC at 1-800-462-8782. Also contact the National Highway Traffic Safety Administration's Auto Safety Hotline at 1-888-DASH-2-DOT (1-888-327-4236). Page 951 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Page 1769 2. Remove the serpentine belt from the accessory drive system. 3. Install the tool onto the power steering pulley. Position the legs of the tool into the outer grooves of the pulley, farthest from the front of the engine. 4. Install the retaining cord around the pulley and to the legs of the tool. 5. Put on the laser safety glasses provided with the tool. 6. Depress the switch on the rear of the tool to activate the light beam. 7. Rotate the power steering pulley as required to project the light beam onto the crankshaft balancer pulley grooves. 8. Inspect for proper power steering pulley alignment. - If the laser beam projects onto the second rib or raised area (1), the pulleys are aligned properly. - If the laser beam projects more than one-quarter rib 0.9 mm (0.035 in) mis-alignment, adjust the position of the power steering pulley as required. - Refer to SI for Power Steering Pulley Removal and Installation procedures. 9. Install the serpentine belt to the accessory drive system in the original orientation. 10. Operate the vehicle and verify that the belt noise concern is no longer present. Tool Information Please visit the GM service tool website for pricing information or to place your order for this tool. Page 3919 Fluid - A/T: Service and Repair Turbo Hydra-Matic 4L60 (700-R4) Checking & Adding Fluid Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface, engine idling in park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, If fluid level is too low, complete loss of drive may occur especially when cold, Which can cause transmission failure. Every 100,000 miles, the oil should be drained, the pan removed, the screen should be cleaned or replaced if applicable, and fresh fluid added. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or use as a tow vehicle, this maintenance should be performed every 15,000 miles. Changing Oil 1. Raise vehicle and position drain pan under transmission pan. 2. Remove front and side attaching bolts form the oil pan. 3. Loosen rear attaching bolts approximately four turns. 4. Carefully pry transmission pan loose and allow fluid to drain. 5. Remove rear attaching bolts, pan and pan gasket. 6. Drain remaining fluid from pan, then clean pan and gasket surfaces with solvent and dry with compressed air. 7. Remove transmission screen. Remove O-ring seal from intake pipe or case bore. 8. Replace screen if applicable, or thoroughly clean screen assembly with solvent and dry with compressed air. 9. Install O-ring on intake pipe, then install screen assembly. 10. Install gasket on pan, then install pan and torque attaching bolts to 12 ft. lbs. 11. Lower vehicle and add approximately 5 qts. of Dexron II or Dexron III type transmission fluid through filler tube. 12. Start engine and let run at idle, then with brakes applied move selector lever through each gear range. 13. Place transmission in Park position and check fluid level. Diagram Information and Instructions Vehicle Speed Sensor/Transducer - Cruise Control: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 2337 Flushing Procedures using DEX-COOL(R) Important: The following procedure recommends refilling the system with DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. This coolant is orange in color and has a service interval of 5 years or 240,000 km (150,000 mi). However, when used on vehicles built prior to the introduction of DEX-COOL(R), maintenance intervals will remain the same as specified in the Owner's Manual. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling system flush and fill machine is not available, drain the coolant and dispose of properly following the draining procedures in the appropriate Service Manual. Refill the system using clear, drinkable water and run the vehicle until the thermostat opens. Repeat and run the vehicle three (3) times to totally remove the old coolant or until the drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with DEX‐COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. Then slowly add clear, drinkable water (preferably distilled) to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and reverify the coolant level. If necessary, add clean water to restore the coolant to the appropriate level. Once the system is refilled, reverify the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. The concentration levels should be between 50% and 65%. Flushing Procedures using Conventional Silicated (Green Colored) Coolant Important: 2004-2005 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX‐COOL(R). The Aveo and Wave are filled with conventional, silicated engine coolant that is blue in color. Silicated coolants are typically green in color and are required to be drained, flushed and refilled every 30,000 miles (48,000 km). The Aveo and Wave are to be serviced with conventional, silicated coolant. Use P/N 12378560 (1 gal) (in Canada, use P/N 88862159 (1 L). Refer to the Owner's Manual or Service Information (SI) for further information on OEM coolant. Important: Do not mix the OEM orange colored DEX-COOL(R) coolant with green colored coolant when adding coolant to the system or when servicing the vehicle's cooling system. Mixing the orange and green colored coolants will produce a brown coolant which may be a customer dissatisfier and will not extend the service interval to that of DEX-COOL(R). Conventional silicated coolants offered by GM Service and Parts Operations are green in color. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling systems flush and fill machine is not available, drain coolant and dispose of properly following the draining procedures in appropriate Service Manual. Refill the system using clear, drinkable water and run vehicle until thermostat opens. Repeat and run vehicle three (3) times to totally remove old coolant or until drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with a good quality ethylene glycol base engine coolant, P/N 12378560, 1 gal (in Canada, use P/N 88862159 1 L), conforming to GM specification 1825M, or recycled coolant conforming to GM specification 1825M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% good quality ethylene glycol base (green colored) engine coolant, P/N 12378560 1 gal., (in Canada, use P/N 88862159 1 L) conforming to GM specification 1825M. Then slowly add clear, drinkable water (preferably distilled) to system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and recheck coolant level. If necessary, add clean water to restore coolant to the appropriate level. Once the system is refilled, recheck the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. Concentration levels should be between 50% and 65%. Parts Information Warranty Information Instruments - Reduced PRNDL Display Visibility Transmission Shift Position Indicator Lamp: Technical Service Bulletins Instruments - Reduced PRNDL Display Visibility Bulletin No.: 02-08-42-004A Date: March 30, 2007 INFORMATION Subject: PRNDL Display Reduced Visibility For Approximately One Minute Models: 2007 and Prior Passenger Cars and Trucks (Including Saturn) 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X with Automatic Headlamp Control and Vacuum Fluorescent PRNDL Indicator Instrument Panel Cluster Supercede: This bulletin is being revised to include additional models and model years. Please discard Corporate Bulletin Number 02-08-42-0004 (Section 08 - Body and Accessories). After backing the vehicle out of a garage or dark environment into a daylight environment, the PRNDL display has reduced visibility for approximately one minute. While the vehicle is parked in a dark environment, the sensor for the automatic headlamp/driving lamps senses that it is dark. When the key is turned to the run/start position, the automatic headlamp module will turn all driving lamps, the instrument panel cluster and PRNDL display ON in the night-time mode. The night-time mode intensity of the instrument panel lamps and PRNDL display is controlled by the automatic headlamp module and can be dimmed further by the customer using the dimming control of the headlamp switch. When the customer then moves the vehicle from the dark environment into the bright sunlight, it will take approximately one minute before the headlamp control module recognizes this as true daylight and not just a bright overhead street lamp shining on the sensor. The headlamp control module will then turn the headlamps off and restore the instrument panel and PRNDL display to full brilliance. Without the time delay, the automatic headlamp control module would switch to the night mode (turn on all driving lamps, instrument panel lamps and PRNDL display would dim) each time the vehicle was driven under an overpass or other darkened environment. This is a normal condition and no repair should be attempted. Ensure the instrument panel backlighting control is in the full bright position. This will help alleviate the condition. You may demonstrate to the customer what happens by placing a repair order over the automatic headlamp control light sensor, which will cause the automatic headlamp control module to switch to the night mode in approximately one minute. All driving lamps will come ON, the instrument panel backlight will be dim, and the PRNDL display will also dim to the night setting in conjunction with the position of the headlamp switch dimming control. Demonstrate to the customer the variance in the instrument panel backlighting and PRNDL display while adjusting the headlamp switch dimming control to both ends of its allowable range. Advise the customer to keep the headlight switch dimming control in the highest position to allow viewing of the PRNDL display in a bright environment. Disclaimer Page 4323 Pinion Gear: Service and Repair Dana/Spicer Fig. 5 Pinion Setting Chart If original ring gear and pinion assembly are to be reused, measure original shim pack and build a new shim pack to the same dimension. If baffle is in the axle assembly, it is considered part of the shim pack. Ring gears and pinions are supplied in matched sets only. If a new gear is being used, verify numbers on pinion and ring gear before proceeding with assembly. On the button end of the pinion there is a +, - , or 0 number which indicates the best running position for each particular gear set. This position is controlled by shims installed behind the inner bearing cup. If baffles or oil slingers are used, they are considered part of the adjusting shim pack. If a new gear set is being installed, note the plus or minus mark on both old and new pinions and adjust thickness of shim pack to compensate for the difference between these two numbers. Refer to chart, Fig. 5, when determining shim size. 1. Install inner shim pack and, on 9-3/4 inch ring gear axle, the oil slinger in inner or rear cup bore, then drive cup into position using suitable tool. 2. Add or remove an equal amount to the outer shim pack as was added to the inner shim pack. 3. Drive outer cup into carrier bore, then press rear pinion bearing onto pinion shaft. 4. Install drive pinion and bearing into differential carrier. 5. Install shims and outer or front pinion bearing. 6. Install companion flange, then the washer and nut on pinion shaft. 7. Measure rotating torque of pinion shaft. Rotating torque should measure 10-20 inch lbs. with original bearings installed, or 20-40 inch lbs. with new bearings installed, discounting torque required to start turning shaft. 8. If rotating torque is not within specifications, adjust shim pack as necessary. Increase outer shim pack to reduce torque, or decrease shim pack to increase torque. 9. Remove nut, washer and companion flange from pinion shaft. 10. Install oil slinger, gasket (if equipped) and oil seal onto pinion shaft. 11. Install companion flange, washer and nut and torque as described is step 7. Page 4019 Fig. 6 TV Cable Adjustment. Astro, Safari & S/T-10/15 Gasoline Engine 1. Depress and hold metal readjust tab. Move slider back through fitting in direction away from throttle body until slider stops against fitting, Figs. 4 through 6. 2. Release metal readjust tab. 3. Open throttle lever to full throttle stop position to automatically adjust cable, then release throttle lever. 4. Check cable for proper operation. If sticking or binding occurs, check system as outlined in TV SYSTEM DIAGNOSIS. Fig. 7 TV Cable Adjustment Diesel Engine Page 6804 Parts Information Parts required to complete this special coverage are to be obtained from General Motors Service and Parts Operations (GMSPO). Customer Notification General Motors will notify customers of this special coverage on their vehicles. Service Procedure Replacement of interior door handle assembly(s) Provide the customer with one or two interior front door handle assemblies. The customer is to self-install the assemblies or pay the dealer for the installation. Application of Lithium Grease Apply lithium based lubricant to the door handle springs. The lubricant should be applied so that it works into and between the spring coils, allowing the coils to move past each other freely. Claim Information Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Interior - Itch Noise From Windshield Pillar Area Instrument Cluster / Carrier: All Technical Service Bulletins Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 2838 Malfunction Indicator Lamp: Service and Repair The Check Engine Lamp will be illuminated when the ignition switch is placed in the On position. When the engine is started, the lamp should go off. If the lamp remains on for 10 seconds or constantly after the engine is started, the self diagnosis system has detected a problem and has stored a code in the system Electronic Control Module (ECM). After diagnosis and repair, the ECM memory can be cleared of codes by removing the ECM fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the Off position. It should be noted, that if battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. Page 630 Rear Of Engine Page 4808 Wheel Cylinder: Fundamentals and Basics REMOVAL - Wheel cylinder retaining bolts, brake line fittings, and bleeder screws are often heavily corroded. Prior to starting the job you should spray these with a penetrating oil. - A line (flare nut) wrench should be used when loosening the brake line fittings. These fittings round off easily. OVERHAUL - Light amounts of corrosion within the cylinder bore and on the piston may be removed with crocus cloth. - Pitting and heavy corrosion should be removed with a hone. When honing the hone should be inserted and withdrawn quickly to achieve a 45 degree crosshatch. - Closely inspect the areas of the cylinder where the pistons seals contact. It is very important these areas are absolutely free of deposits, corrosion, or pitting. - Remove the bleeder screw and verify that the passage is clear. - Leave the bleeder open when installing pistons and cups into the cylinder bore. If the bleeder is closed a large amount of air will be forced into the brake lines. - Use brake assembly lubricant to coat the cylinder bore, pistons, and cups. Clean brake fluid is an acceptable lubricant when assemblying the wheel-cylinder but brake assembly lubricant is much slicker and minimizes the chance that the cups will be damaged. WARNING: Do not use a petroleum based grease or oil to lubricate the wheel-cylinder components. This will cause the seals and cups to swell and deteriorate. - When reassemblying the wheel-cylinder it is helpful to follow this sequence: 1. Rear cup (verify the cup is inserted properly, flat side towards the piston, concave side towards the center) 2. Rear piston 3. Rear dust cap (this prevents the rear cup and piston from popping back out when the spring and front components are installed). 4. Spring 5. Front cup 6. Front piston 7. Front dust cap INSTALLATION Attach the brake fluid line fitting loosely to the wheel-cylinder prior to inserting and tightening the retaining bolts. The brake fluid line fitting is much easier to attach and start turning with the wheel-cylinder loose. WARNING: Don't forget to tighten the brake line fitting after the retaining bolts are tightened. - Leave the wheel-cylinder bleeder screw open and place a drip pan under the rear brake assembly. Refill the master-cylinder with new brake fluid and let the fluid gravity bleed through the open bleeder screw. When brake fluid begins to drip from the bleeder, close the bleeder screw. NOTE: The brake system will still need to be flushed and bled, but this makes starting the process much easier. Page 5708 Removing The Lower Ball Joint Installing The Lower Ball Joint SPECIAL TOOLS REQUIRED (or equivalents) ^ J-9519-D, Ball joint remover and installer set. ^ J-23742, Ball joint separator. REMOVE OR DISCONNECT 1. Raise the vehicle and support the frame with suitable safety stands. 2. Wheel and tire assembly. Place a floor jack under the control arm spring seat and raise it until it supports the control arm. WARNING: Floor jack must remain under the control arm spring seat during removal and installation to retain the spring and control arm in position. Failure to do so could result in personal injury. 3. Caliper and support with a piece of wire to prevent damage to the brake line. 4. Cotter pin (68) and the nut (67). Use J-23742 to break the ball joint loose from the knuckle. 5. Lower control arm (40) out of the opening in the splash shield. Use a putty knife or similar tool to guide control arm past splash shield. NOTE: Block the knuckle assembly out of the way by placing a wooden block between the frame and upper control arm. 6. Grease fittings and lower ball joint (69) from the lower control arm (40). 7. Inspect the tapered hole in the steering knuckle and remove any dirt. If the hole is out of round, deformed or damaged, the knuckle must be replaced. INSTALL OR CONNECT 1. Press the new ball (69) joint into the lower control arm (40) using J-9519-D and locate the grease seal facing inboard. 2. Ball joint stud into the steering knuckle. CAUTION: When fasteners are removed, always reinstall them at the same location from which they were removed and use the correct torque value. If a fastener needs to be replaced, use a fastener of the correct size and strength. Failure to do so may result in component/system damage or malfunction. 3. Stud nut (67) onto the stud and tighten to 113 Nm (83 ft lbs). Align the slot in the stud nut with the hole in the stud by tightening. 4. New cotter pin (68) to the stud. 5. Grease fittings and lubricate the ball joint until grease appears at the seal. 6. Caliper. 7. Wheel and tire assembly, then lower the vehicle. 8. Check the front end alignment. Page 7033 Service and Repair Fuel Pressure Release: Service and Repair Fuel Supply System CMFI FUEL PRESSURE RELEASE PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure - Connect fuel pressure gauge to fuel pressure connection tap. Wrap a shop towel around fitting while connecting gauge to avoid spillage. - Install bleed hose into an approved container and open valve to bleed system pressure. Fuel connections are now safe for servicing. - Drain any fuel remaining in gauge into an approved container. Page 7593 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 6197 Compressor Clutch Bearing: Service and Repair With HR6-HE Compressor Remove or Disconnect 1. Remove the clutch plate and hub assembly. Installing - Removing Pulley Rotor & Bearing Assembly Retainer Ring 2. Remove rotor and bearing assembly retaining ring, using snap ring pliers J 6083. Installing Pulley Rotor/Bearing Puller Guide Page 6082 RH Side Of Dash Panel, In Engine Compartment Heater Wiring - Without A/C Page 3720 PROM - Programmable Read Only Memory: Application and ID Introducing the GM PROM Cross Reference Index This PROM cross reference index provides tables that let you use a PROM identification (ID) code to identify the PROM installed in the engine control module (ECM) on most GM vehicles. The code can be either - or both - the internal "scan ID" code or the external PROM code. From the PROM identification, you can find the part number of the PROM and trace the PROM history to determine if any revised PROM's have been issued to supersede the one in the vehicle. The PROM history for a specific vehicle lists a succession of superseding PROM's ending with the most recent PROM released as a service part for the vehicle. PROM's that were released as service parts and explained in a technical service bulletin (TSB) are listed with a description of why the PROM was issued. In most cases, the applicable TSB also is referenced. This index lists ECM PROM's for the 1980-95 vehicles. It does not contain ID codes and part numbers for all PROM's used in all GM vehicles. NOTE: GM flash PROM's (EEPROM's) can only be updated at GM Dealerships with factory-supplied equipment. These cars will not display a PROM ID. By following the steps outlined below, you can use the PROM index to determine if the problem you are diagnosing can possibly be corrected by installing a revised PROM. The PROM index tables are organized by model year, engine displacement, and engine code (the eighth digit of the Vehicle Identification Number). The table columns are arranged as shown below: Example of Table Column Arrangement SCAN PROM PROM PART SUPERSEDING TSB REFERENCE ID CODE (BCC) NUMBER ID PART NUMBER NUMBER (1) (2) (3) (4) (5) .............................................................................................................................................................. ........................................................................ 9461 8958 AMU 16058955R 8290 01228290 86194 Column 1, SCAN ID: The scan ID is the internal PROM identification number transmitted on the ECM data stream and displayed by the scanner as PROM ID. The PROM records for each year and engine are listed numerically by this scan ID. Column 2, PROM CODE: These are the numbers and letters marked on the top of the PROM itself. The numbers are often referred to as the "external PROM ID." The letters are often called the "broadcast code." Together they are the external PROM code. Column 3, PROM P/N: This is the GM part number for the PROM identified by the codes in columns 1 and 2. Column 4, SUPERSEDING ID PROM PART NUMBER: Use the superseding scan ID to locate the newer PROM in the table. If the scan ID for the superseding PROM is not known, the PROM broadcast code is listed here. If the PROM is superseded by a newer PROM, that part number is listed here. Column 5, TSB REFERENCE NUMBER The TSB NUMBER column identifies the original TSB that released this PROM for service. Whenever possible you should refer to the TSB for additional information before changing a PROM. The bulletin may list other parts that must be installed when the PROM is changed, or it may provide additional troubleshooting information. To find a TSB, see Reading Technical Service Bulletins. See: Reading Technical Service Bulletins This will display all the TSB's for that particular vehicle. EXPANDED FOOTNOTES Here you will find SUPERSEDING SCAN ID, PROM PART NUMBERS, symptoms and additional parts that need to be replaced when servicing the PROM. Control Module Engine Control Module: Locations Control Module Figure 1 LOCATION Below RH Side Of I/P. Page 2009 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Page 7535 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 7586 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 4107 Valve Body: Technical Service Bulletins A/T - 700R4 Valve Body Modification SIL 85-21 SUBJECT: 700-R4 For start of production 1985, the converter clutch shift valve train was eliminated on units where the converter clutch is controlled by the computer. Page 5268 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7521 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 6636 Rear Door Power Window Page 5653 4. Insufficient pump pressure. 5. Excessive internal pump leakage. 6. Excessive internal steering gear leakage. Momentary Increase In Effort When Turning Wheel Fast 1. High internal leakage. 2. Low fluid level. 3. Insufficient pump pressure. Poor Return of Steering Wheel to Center 1. Front wheel alignment. 2. Wheel bearing worn. 3. Joints from column to steering gear binding or loose. 4. Tie rod end binding. 5. Ball joint binding. 6. Steering wheel rubbing against turn signal housing. 7. Tight or frozen steering shaft bearings. 8. Steering gear adjustments. 9. Sticky or plugged steering gear valve. 10. Steering column shaft seal rubbing shaft. Rattle or Chuckle Noise 1. Pressure hose grounding out. 2. Tie rod ends loose. 3. Rack bearing adjustment loose. Steering Wheel Surges/Jerks When Turning W/Engine Running 1. Insufficient pump pressure. 2. Sticky steering gear valve. Locations Air Intake Ducts 4.3W S/T Utility Page 4324 Pinion Gear: Service and Repair Timken/Rockwell - 12 Inch Ring Gear Fig. 1 Exploded View Of Timken/Rockwell Drive Axle With 12 inch Ring Gear DISASSEMBLY 1. Tap or press pinion from cage, taking care not to damage shaft threads, then remove outer pinion bearing, Fig. 1. 2. Remove spacer from pinion, then the inner bearing, using suitable separator and press or puller. 3. If straddle bearing must be replaced, remove snap ring and washer, then the bearing, using suitable puller. 4. If bearings are to be replaced, press outer races from bearing cage, taking care not to distort cage. 5. Inspect components as outlined, and replace as needed, keeping components in order for assembly. ASSEMBLY & PRELOAD 1. When installing new cups, press them firmly against pinion bearing cage shoulders. 2. Lubricate bearings and cups with suitable lubricant. 3. Press rear thrust and radial bearings firmly against pinion shoulders, using suitable sleeve that will bear only on bearing inner race. 4. Install radial bearing lock ring, then squeeze ring into pinion shaft groove. 5. Insert pinion and bearing assembly in pinion cage and position spacer or spacer combination over pinion shaft. 6. Press front bearing firmly against spacer. 7. Rotate cage several revolutions to assure normal bearing contact. 8. Press flange or yoke against forward bearing and install washer and pinion shaft nut. 9. Place pinion and cage assembly over carrier studs, hold flange with suitable tool and torque pinion shaft nut to 240 ft. lbs. 10. Check pinion bearing preload torque. If rotating torque is not within 5 to 15 pound inches, disassemble, adjust spacer, reassemble, and recheck preload torque. Use thinner spacer to increase or thicker spacer to decrease preload. Body - Vehicle Glass Distortion Information Quarter Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 1646 Parts are currently available from GMSPO. Calibration Information for 1992 Model Year Vehicles with Sleeve Bearing Engines: Torque Specifications Page 2047 1. Balance shaft rear bearing using J 38834. - Dip the bearing in clean engine oil before installation. - Install the bearing with the flat edge and the manufacturers markings facing the front of the engine. 2. Balance shaft into the block using J 36996 and J 8092. - Dip the front balance shaft bearing into clean engine oil before assembly. IP Dimmer Control - Proper Setting Instrument Cluster / Carrier: All Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Page 1523 II. OVER TORQUING OF WHEEL NUTS: 1. A TORQUE WRENCH MUST BE USED to insure that the wheel nuts are tightened to specification. This should be done in two steps using the star pattern. First, snug the nuts down by hand. Then, using the star pattern and a torque wrench, tighten the wheel nuts to about half the final torque. Finally, tighten the wheel nuts to specification using the star pattern and a torque wrench. 2. NEVER use lubricants or penetrating fluids on wheel studs, nuts, or mounting surfaces, as this can raise the actual torque on the nut without a corresponding torque reading on the wrench. Wheel nuts, studs, and mounting surfaces must be clean and dry. Page 2977 Throttle Position Sensor: Mechanical Specifications Throttle Position Sensor 18 in.lb Page 8346 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 5543 Figure 1: Full Tread View - "NORMAL" Tire "Feathering" Wear on the Shoulder/Adjacent/Center Ribs Figure 2: Tire Shoulder View Example 1 - "NORMAL" Tire "Feathering" Wear on the Shoulder Figure 3: Tire Shoulder View Example 2 - "NORMAL" Tire "Feathering" Wear Figure 4: Detail Side View of Tire Shoulder Area - "NORMAL" Tire "Feathering" Wear Important When a wheel alignment is deemed necessary for tire wear, be sure to document on the repair order, in as much detail as possible, the severity and type of tire wear (e.g., severe center wear or severe inside or outside shoulder wear) and the position of the tire on the vehicle (RF, LF, LR, RR). Please note the customer's concern with the wear such as, noise, appearance, wear life, etc. A field product report with pictures of the tire wear condition is recommended. Refer to Corporate Bulletin Number 02-00-89-002J and #07-00-89-036C. 4. Other repairs that affect wheel alignment; e.g., certain component replacement such as suspension control arm replacement, engine cradle adjustment/replace, steering gear replacement, steering tie rod replace, suspension strut/shock, steering knuckle, etc. may require a wheel alignment. Important If other components or repairs are identified as affecting the wheel alignment, policy calls for the wheel alignment labor time to be charged to the replaced/repaired component's labor operation time rather than the wheel alignment labor operations. Important Vibration type customer concerns are generally NOT due to wheel alignment except in the rare cases; e.g., extreme diagonal wear across the tread. In general, wheel alignments are NOT to be performed as an investigation/correction for vibration concerns. "Normal Operation" Conditions Vehicle Lead/Pull Due to Road Crown or Slope: As part of "Normal Operation," vehicles will follow side-to-side or left to right road crown or slope. Be sure to verify from the customer the types of roads they are driving as they may not recognize the influence of road crown on vehicle lead/pull and steering wheel angle. If a vehicle requires significant steering effort to prevent it from "climbing" the road crown there may be an issue to be looked into further. Important Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge: All Technical Service Bulletins Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 7558 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 5618 Fig. 10 Pressure Plate Alignment Fig. 11 Thrust plate compression 1. Press sleeve into housing using a suitable socket and press. 2. Install dowel pin, seal and pressure plate spring. Fig. 9. 3. Install O-ring seal, pressure plate and dowel pins. Mark top of pressure plate where pin enters from underneath to ease alignment with dowel pin during assembly, Fig. 10. 4. Lubricate O-ring, pump ring, rotor and vanes with power steering fluid. Install vanes and rotor with rounded edge facing away from rotor. Ensure counterbore of rotor faces driveshaft end of housing. 5. Install pump ring with identification marks facing up, then install O-ring seal and thrust plate. Thrust plate dimples must line up with bolt holes in housing and plate must engage pump ring dowel pins. 6. Using a press to compress thrust plate, install retaining plate with the center opening of ring with bolt hole nearest the access hole, Fig. 11. 7. Using a suitable socket and press, install driveshaft seal into housing until it bottoms. Fig. 6 Driveshaft & bearing removal Fig. 5 Driveshaft retaining ring removal 8. Install bearing onto driveshaft, Fig. 6, then slide assembly into housing while rotating driveshaft so shaft serrations engage with rotor. 9. Insert retaining ring ensuring large tab of ring is properly located. Refer to Fig. 5. Page 4312 Fig. 10 Pinion depth gauge tool installation. Corvette Adjustment 1. Install pinion bearing races in housing using a suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, Fig. 8, noting the following: a. Assemble gauge plate onto preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. c. Rotate tool to ensure bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. of torque, which is required to rotate stud. To prevent damage to bearing, tighten nut in small increments, checking rotating torque after each adjustment. e. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. f. Mount arbor and plunger assembly in housing, ensuring side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving, Fig. 9. 4. Mount dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 3/4 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. Installation 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with a drift while assistant holds pinion in place. Old pinion nut and a large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. Page 4783 Hydraulic Assembly: Service and Repair Rear Wheel Anti-Lock Brake System Fig. 46 ECU & Control Valve Assembly Installation 1. Disconnect brake lines from control valve, the plug lines and open fittings. 2. Remove bolts (25) securing control valve, Fig. 46, and support valve assembly. Do not allow valve assembly to hang from wiring. 3. Disconnect electrical connectors and remove control valve assembly. 4. Reverse procedure to install, then bleed brakes as needed. Page 1142 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Page 8308 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 8404 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Engine - High Oil Pressure Reading at Start-Up Oil Pressure Gauge: Customer Interest Engine - High Oil Pressure Reading at Start-Up Number: 93-60-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268306 ASE No.: A1, A8 Subject: HIGH OIL PRESSURE READING AT START-UP Model and Year: 1992-93 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L, AND 5.7L ENGINES Some 1992 and 1993 Chevrolet Light Duty Trucks with oil pressure gauges built after 6/15/92 may exhibit high oil pressure readings at start up, especially when cold. Engines produced after 6/15/92 were built with an enhanced oil pump capable of producing approximately 10 psi more pressure than the previous pump. This may cause the gauge to temporarily read as high as 60 psi during start up. The length of time the oil pressure stays high will depend on oil viscosity, engine temperature, and ambient temperature. This condition will not cause any ill effects on the engine or gauge and unless there are other symptoms to indicate an oil pressure or gauge problem such as very low pressure after warm up, rapid fluctuation, engine noise etc. no repairs should be attempted. Replacing the oil pump or gauge system parts will not be effective. Build date of the engine can be verified by the engine code. The location of this code is illustrated in section OA of the appropriate service manual. The engine code is 8 positions long with an alpha plant designator in the first position, followed in the next four positions by the month and day; for example T0615xxx would indicate that this engine was built in Tonawanda on June 15th and, therefore, has the enhanced oil pump. The plant code is insignificant because all 4.3L, 5.0L, and 5.7L plants began using the enhanced oil pump on the same day. Page 7539 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you EGR Filter Replacement EGR Filter: Service and Repair EGR Filter Replacement EVRV Filter Replacment Removal and Installation - Grasp and pull the filter OFF with a rocking motion. - Push the new filter on making sure that the cut-out for the wires is properly aligned. Page 8208 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 857 available, measurements may also be clearly and legibly handwritten into the Wheel Alignment Repair Order Questionnaire attached to this bulletin. 4. Attach the Wheel Alignment Repair Order Questionnaire below along with the print-out of "Before" and "After" wheel alignment measurements to the Repair Order and retain for use by GM. Wheel Alignment Equipment and Process Wheel alignments must be performed with a quality machine that will give accurate results when performing checks. "External Reference" (image-based camera technology) is preferred. Please refer to Corporate Bulletin Number 05-00-89-029B: General Motors Dealership Critical Equipment Requirements and Recommendations. Requirements: - Computerized four wheel alignment system. - Computer capable of printing before and after alignment reports. - Computer capable of time and date stamp printout. - Racking system must have jacking capability - Racking system must be capable of level to 1.6 mm (1/16 in) - Appropriate wheel stops and safety certification - Built-in turn plates and slip plates - Wheel clamps capable of attaching to 20" or larger wheels - Racking capable of accepting any GM passenger car or light duty truck - Operator properly trained and ASE-certified (U.S. only) in wheel alignment Recommendations: Racking should have front and rear jacking capability. Equipment Maintenance and Calibration: Alignment machines must be regularly calibrated in order to give correct information. Most manufacturers recommend the following: - Alignment machines with "internal reference" sensors should be checked (and calibrated, if necessary) every six months. - Alignment machines with "external reference" (image-based camera technology) should be checked (and calibrated, if necessary) once a year. - Racks must be kept level to within 1.6 mm (1/16 in). - If any instrument that is part of the alignment machine is dropped or damaged in some way, check the calibration immediately. Check with the manufacturer of your specific equipment for their recommended service/calibration schedule. Wheel Alignment Process When performing wheel alignment measurement and/or adjustment, the following steps should be taken: Preliminary Steps: 1. Verify that the vehicle has a full tank of fuel (compensate as necessary). 2. Inspect the wheels and the tires for damage. 3. Inspect the tires for the proper inflation and irregular tire wear. 4. Inspect the wheel bearings for excessive play. 5. Inspect all suspension and steering parts for looseness, wear, or damage. 6. Inspect the steering wheel for excessive drag or poor return due to stiff or rusted linkage or suspension components. 7. Inspect the vehicle trim height. 8. Compensate for frame angle on targeted vehicles (refer to Wheel Alignment Specifications in SI). Satisfactory vehicle operation may occur over a wide range of alignment angles. However, if the wheel alignment angles are not within the range of specifications, adjust the wheel alignment to the specifications. Refer to Wheel Alignment Specifications in SI. Give consideration to excess loads, such as tool boxes, sample cases, etc. Follow the wheel alignment equipment manufacturer's instructions. Measure/Adjust: Important Prior to making any adjustments to wheel alignment on a vehicle, technicians must verify that the wheel alignment specifications loaded into their wheel alignment machine are up-to-date by comparing these to the wheel alignment specifications for the appropriate model and model year in SI. Using incorrect and/or outdated specifications may result in unnecessary adjustments, irregular and/or premature tire wear and repeat customer concerns Locations Turn And Hazard Lamp Flashers Main Bearing Dimensions Crankshaft & Bearings Interior - Itch Noise From Windshield Pillar Area Dashboard / Instrument Panel: All Technical Service Bulletins Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 7739 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 6522 Disclaimer Page 7824 Use applicable labor time guide for labor hours. Page 1174 procedures and short-cutting refrigerant recycling times. Use the following procedure for testing and correcting air contamination in your A/C service equipment. 1. Make certain that the ACR4 equipment has not been used for at least 12 hours. It is recommended that the equipment be left in an area where the temperature will remain constant overnight to allow the temperature of the refrigerant in the tank to stabilize. 2. Record the surrounding air temperature next to the ACR4 refrigerant tank. Important: A major assumption is that the ambient air temperature next to the tank represents the refrigerant temperature in the tank. Failure to take care in measuring the temperature could result in unnecessary work. 3. Close both liquid (blue) and vapor (red) valves on the ACR4 tank. 4. Disconnect low side (blue) service hose from the back of the ACR4. 5. Slowly disconnect the tank vapor hose (red) from the back of the ACR4 and connect it to the low side service port. 6. Open the vapor (red) valve on the tank and record the tank pressure on the low side gage. 7. Restore hoses to the original position. 8. Referring to the Table, find the ambient temperature measured in Step 2. Compare the pressure reading from Step 6 to the "maximum allowable pressure". If the pressure reading from Step 6 is less than the "maximum allowable pressure", no further action is necessary. Important: The closer the tank pressure is to the desired tank pressure, the better the A/C system will perform. 9. If the pressure reading from Step 6 exceeds the maximum allowable pressure from the Table, open both tank valves and operate the ACR4 through 4 or 5 evacuation cycles. This will activate the automatic air purge to lower the tank pressure. Important: Station should not be connected to vehicle. 10. Repeat the tank pressure checking procedure the next day to determine if the pressure has been reduced to acceptable levels. If the tank pressure has been reduced but is not acceptable, cycle with ACR4 through more evacuation cycles and recheck the next day. Continue process until acceptable pressure is obtained. If the tank pressure is not reduced through the evacuation cycling, then Kent-Moore should be contacted at 1-800-345-2233. Page 412 Symbol Identification Brakes - Rotor & Hub Flange Cleaning Tool Revision Brake Rotor/Disc: Technical Service Bulletins Brakes - Rotor & Hub Flange Cleaning Tool Revision File In Section: 5 - Brakes Bulletin No.: 73-50-37 Date: January, 1998 INFORMATION Subject: Revision to J 42450 Tool; Proper Brake Rotor and Hub Flange Surface Cleaning Models: 1998 and Prior Passenger Cars and Light Duty Trucks - with Disc Brakes (Rotor and Hub Separate) This bulletin is being revised to update the following text. This bulletin is being issued to inform the dealer about a revision to tool J 42450 and reinforce the need for proper hub flange and brake rotor mating surface cleaning during service. Tool J 42450 is a cleaning pad arbor and pad system that fits over the wheel stud and cleans the portion of the hub surface that is very difficult to reach with normal rotary cleaning pads. Tool J 42450 is being revised to J 42450-A to improve the hook and loop material retention. Any dealer experiencing problems with tool J 42450 should contact Kent-Moore at 1-800-345-2233 for a revised arbor at no charge. Anytime the brake rotor has been separated from the hub bearing flange or if rotor machining is necessary, the rotor and hub should be marked to maintain the original position. Clean the hub flange of all dirt and foreign material using special tool J 42450 or J 42450-A. Clean both sides of the brake rotor hub using an aggressive (80 grit) abrasive sanding pad on a rotary disc. Properly cleaning the rotor surfaces before rotor machining or reassembly ensures that dirt and corrosion will not add lateral runout to the rotor. Proper cleaning of the hub flange will also minimize the stack-up of lateral runout. On reassembly, the rotor should be reinstalled aligning the marks made on disassembly. Always use a torque wrench or the appropriate Torque Socket found in J 39544-KIT on an impact wrench when installing the wheel and tire assembly. Torque all wheel nuts using the correct sequence and torque. Refer to the Tire and Wheel Sub-Section in the applicable Service Manual. Excessive torque or torque variation between wheel nuts may cause distortion of the hub and rotor mating surface. This distortion may cause lateral runout and lead to brake pulsation. Specifications Evaporative Emission Control Canister: Specifications Vapor Canister Clamp Bolt Torque Vapor Canister Clamp Bolt Torque Vapor Canister Clamp Bolt 41 to 62 in.lb Page 3401 Use applicable labor time guide for labor hours. Page 206 Fuel Pump Relay: Service and Repair Relay Center 2.5L,2.8L S REMOVE/DISCONNECT - Verify that ignition switch is in the "OFF" position. - Retainer, if installed. - Electrical connector. - Fuel pump relay by depressing bracket clip at rear of relay, or removing bolts from retaining bracket. INSTALL/DISCONNECT - Fuel pump relay. - Electrical connector. - Retainer. - Verify correct operation to confirm repair. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 7206 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 6899 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Left Side Knock Sensor Engine Wiring, LH Side Page 8048 AC Delco Service Centers Page 134 Symbol Identification Page 5828 Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. Final Inspection 1. After remounting and inflating the tire, check both beads, the repair and the valve with a water and soap solution in order to detect leaks. 2. If the tire continues to lose air, the tire must be demounted and reinspected. 3. Balance the tire and wheel assembly. Refer to Tire and Wheel Assembly Balancing - OFF Vehicle. For additional tire puncture repair information, contact: Rubber Manufacturers Association (RMA) Disclaimer Page 5236 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 7567 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Locations Typical Distributor Components Page 4665 Brake Rotor/Disc: Testing and Inspection PURPOSE In the manufacturing of the brake rotor all the tolerances regarding surface finish, parallelism, and lateral runout are held very closely. The maintenance of these tolerances provide the surface necessary to prevent brake roughness. Light scoring of the rotor surface not in excess of 01.5 mm (0.060-inch) in depth is normal. This condition does not affect the brake operation. Some discoloration or wear of the disc surface is normal and does not require re-surfacing when linings are replaced. SPECIFICATIONS - See: Specifications LATERAL RUNOUT Lateral runout is the movement of the rotor from side to side as it rotates on the spindle. This could also be referred to as "rotor wobble". This movement causes the brake pad and piston to be knocked back into it's bore. This results in additional pedal travel and a vibration during braking. Checking Lateral Runout 1. Tighten the wheel bearings to eliminate all freeplay. Page 6975 Fig. 25 Radio Receiver Removal & Installation Fig. 26 Speaker Removal & Installation 1. Disconnect battery ground cable. 2. Remove lamp switch trim plate attaching screws, then pull lamp switch rearward and disconnect wiring harness, Fig. 23. 3. Remove A/C and heater control assembly attaching screws, then pull control assembly rearward and disconnect electrical connector. 4. Remove filler panel attaching screws and filler panel, Fig. 24. 5. Remove instrument cluster housing attaching nuts and cluster housing. 6. Remove instrument cluster attaching nuts, then pull cluster rearward and disconnect electrical connector and speedometer cable. 7. Disconnect transmission control cable from steering column, then remove steering column attaching bolts and lower steering column. Page 37 Symbol Identification Wheels - Finish Damage During Off Car Balancing Wheels: All Technical Service Bulletins Wheels - Finish Damage During Off Car Balancing BULLETIN NUMBER: 93-3E-67 SECTION: 3E Wheels & Tires NUMBER: 3 CORPORATE REFERENCE NUMBER: 3935O2R DATE: June 1993 SUBJECT: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING MODELS: 1985-93 MODELS WITH ALUMINUM WHEELS Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car vehicle balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make Diagram Information and Instructions Cruise Control Switch: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 6336 Flushing Procedures using DEX-COOL(R) Important: The following procedure recommends refilling the system with DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. This coolant is orange in color and has a service interval of 5 years or 240,000 km (150,000 mi). However, when used on vehicles built prior to the introduction of DEX-COOL(R), maintenance intervals will remain the same as specified in the Owner's Manual. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling system flush and fill machine is not available, drain the coolant and dispose of properly following the draining procedures in the appropriate Service Manual. Refill the system using clear, drinkable water and run the vehicle until the thermostat opens. Repeat and run the vehicle three (3) times to totally remove the old coolant or until the drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with DEX‐COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. Then slowly add clear, drinkable water (preferably distilled) to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and reverify the coolant level. If necessary, add clean water to restore the coolant to the appropriate level. Once the system is refilled, reverify the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. The concentration levels should be between 50% and 65%. Flushing Procedures using Conventional Silicated (Green Colored) Coolant Important: 2004-2005 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX‐COOL(R). The Aveo and Wave are filled with conventional, silicated engine coolant that is blue in color. Silicated coolants are typically green in color and are required to be drained, flushed and refilled every 30,000 miles (48,000 km). The Aveo and Wave are to be serviced with conventional, silicated coolant. Use P/N 12378560 (1 gal) (in Canada, use P/N 88862159 (1 L). Refer to the Owner's Manual or Service Information (SI) for further information on OEM coolant. Important: Do not mix the OEM orange colored DEX-COOL(R) coolant with green colored coolant when adding coolant to the system or when servicing the vehicle's cooling system. Mixing the orange and green colored coolants will produce a brown coolant which may be a customer dissatisfier and will not extend the service interval to that of DEX-COOL(R). Conventional silicated coolants offered by GM Service and Parts Operations are green in color. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling systems flush and fill machine is not available, drain coolant and dispose of properly following the draining procedures in appropriate Service Manual. Refill the system using clear, drinkable water and run vehicle until thermostat opens. Repeat and run vehicle three (3) times to totally remove old coolant or until drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with a good quality ethylene glycol base engine coolant, P/N 12378560, 1 gal (in Canada, use P/N 88862159 1 L), conforming to GM specification 1825M, or recycled coolant conforming to GM specification 1825M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% good quality ethylene glycol base (green colored) engine coolant, P/N 12378560 1 gal., (in Canada, use P/N 88862159 1 L) conforming to GM specification 1825M. Then slowly add clear, drinkable water (preferably distilled) to system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and recheck coolant level. If necessary, add clean water to restore coolant to the appropriate level. Once the system is refilled, recheck the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. Concentration levels should be between 50% and 65%. Parts Information Warranty Information Page 6748 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Testing and Inspection Fuel Pump Control Unit: Testing and Inspection PROCEDURE: - Disconnect fuel module - With test light and ignition "ON", probe connector terminal "C" to ground. Circuit is OK if light is "ON". There is an open if the light is "OFF". - Probe connector terminals "C" to "D" with test light. Circuit is OK if light is "ON". There is an open in the ground circuit if light is "OFF". - Ignition "OFF", probe connector terminals "A" to "D" with test light. Ignition "ON", test light should illuminate for two seconds. There is an open in the circuit if the light is "OFF". - Replace fuel module if there is no twenty second fuel pump operation. Page 2617 Knock Sensor: Description and Operation Electronic Spark Control Circuit Knock Sensor (KS) Sensor PURPOSE Varying octane levels in today's gasoline can cause detonation (also known as spark knock) in an engine. The Knock Sensor (KS) system has various knock sensors that are used on all engines except the 2.5L. The KS system reduces spark knock (detonation) in the engine. This allows the engine to have a maximum spark advance for improved driveablity and fuel economy. CONSTRUCTION This KS system has three main components: - KS Module. - Knock sensor - ECM OPERATION The knock sensor detects abnormal vibration (spark knocking) in the engine. The knock sensor is mounted in the engine block near the cylinders. The KS module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the Ignition Control (IC) to reduce spark knocking. The KS module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the knock sensor. This allows the ECM to maintain maximum timing advance under various engine load conditions. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards IC to reduce spark knock. Page 7793 Door Switch: Locations RH Rear Door Jamb Switch In RH B-Pillar Page 2518 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Page 2401 Exhaust Manifold: Service and Repair EXCEPT TURBO 1. Disconnect battery ground cable. 2. Raise and support vehicle. 3. Disconnect exhaust pipe from manifold. 4. Lower vehicle, then remove spark plug wires from spark plugs. 5. Remove power steering and alternator rear bracket from left manifold. 6. Remove air cleaner with heat stove pipe and cold air intake pipe. 7. Remove exhaust manifold bolts and washers, then the manifold. 8. Reverse procedure to install. TURBO Left 1. Disconnect battery ground cable, then remove air cleaner and duct assembly. 2. Remove turbocharger air inlet elbow and upper fan shroud. 3. Loosen fan nuts, then remove serpentine drive belt. 4. Remove fan and pulley assembly, then the power steering pump pulley. 5. Remove rear brace at generator, then raise and support vehicle. 6. Remove left front tire and wheel assembly, then the left wheelhouse panel. 7. Disconnect power steering inlet and outlet hoses from pump. 8. Remove oil filter lines bracket from power steering pump, then the steering column intermediate shaft. 9. Disconnect exhaust crossover pipe from left exhaust manifold. 10. Disconnect power steering pump and rear brace as an assembly from front bracket. 11. Disconnect spark plug wires from plugs, then remove spark plugs. 12. Remove exhaust manifold attaching bolts and studs. 13. Remove manifold lock tabs, washers and heat shields, then the manifold. 14. Reverse procedure to install. Right 1. Disconnect both battery cables, then drain engine coolant from radiator. 2. Remove battery tray and vacuum tank. 3. Remove turbocharger oil feed hose and coolant return pipe. 4. Disconnect oxygen sensor electrical connector, then raise and support vehicle. 5. Remove right front tire and wheel assembly, then the wheelhouse panel. 6. Disconnect exhaust system from catalytic converter. 7. Remove catalytic converter support bolts, then lower vehicle. 8. Remove turbocharger as described in TURBOCHARGER. 9. Remove exhaust crossover pipe from exhaust manifold. 10. Disconnect spark plug wires from plugs, then remove spark plugs. 11. Remove charge air cooler lower supports, exhaust manifold attaching bolts and studs, lock tabs, washers and heat shields. 12. Remove exhaust manifold. 13. Reverse procedure to install. Page 6426 ^ PAG oil used for future service if needed (mark PAG on box on label, Figure 6). ^ HR6 or R4 original compressor RETAINED - add 8 oz FAG oil to system ^ V5 original compressor RETAINED - add 9 oz V5 Retrofit oil to system. If V5 Retrofit oil is not available from GMSPO, REPLACE THE COMPRESSOR. c. Based on the above chart, add oil if needed. Use the new oil bottle and the extended tube kit, J 39500-71. Fill the bottle with at least 10 oz of oil. Attach the new bottle to the back of the ACR4, and open the oil fill valve. Allow the correct amount of oil to be drawn into the system. DO NOT allow the oil level to drop below the end of the pickup tube. This will prevent any air from being drawn into the system. If any oil was removed during the R-12 recovery evacuation steps, DO NOT add additional oil to replace it. d. Determine the correct amount of R-134a to use. Check the existing label of the vehicle for the R-12 charge amount. Use the formula {(R12 x .9) - .25 lb = R-134a} to determine the correct charge. This can also be stated as: Take 90% of the R12 charge, and subtract 1/4 lb. Follow the directions for the ACR4 cart to recharge the system. At the end of the process, "CPL" will be displayed. Close the high side valve. e. Start the vehicle, turn on the A/C system, and confirm that pressures are within normal operating ranges, as shown in the 1994 Service Manual. The 1994 Service Manuals can be used as a reference for diagnosis and specification of retrofitted systems. On some vehicles with automatic A/C controls or low charge diagnostics, the A/C compressor may not engage if any diagnostic codes were set during the retrofit. Check to see if any codes were set in either the HVAC or Engine Control systems. If they were, clear the codes following the directions in the Service Manual. Page 1017 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 3211 - An updated engine control calibration, or service procedure, may be available to make the engine less susceptible to low volatility fuels. 3. If basic checks do not reveal a vehicle fault, then advise the customer that fuel quality may be an issue. Recommend the following actions: Change brands of fuel - Use 87 octane gasoline, unless the vehicle is designed for premium gasoline. - Try to empty the fuel tank as much as practical before refilling. - Run a minimum of three tanks of new fuel before returning for service. 4. If above steps are ineffective, do not proceed with additional vehicle diagnosis and/or parts replacement until the fuel tank has been drained and refilled with a known good quality gasoline AT THE DEALERSHIP. 5. If the problem remains refer to service manual, service bulletins and/or technical assistance. Page 983 Drive Belt: Service and Repair Fig. 20 Serpentine Drive Belt Routing 1. Remove belt tensioner pulley retaining bolt. 2. Remove belt tensioner pulley. then the belt. 3. Reverse procedure to install, refer to Fig. 20 for belt routing. Page 5106 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Control Module Replacement Engine Control Module: Service and Repair Control Module Replacement Figure 1 CAUTION [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, Do NOT touch the connector pins or soldered components on the circuit boards. NOTE When replacing a production control module with a service controller, transfer the broadcast code and production control module part number to the controller label. DO NOT record information on the access cover. REMOVE/DISCONNECT - Negative battery terminal. - Passenger side kick panel. - Hush panel if equipped. - Mounting screw. - Control module from mounting bracket. - VSS buffer connector and rotate control module to ease removal. - Control module harness connectors. - Mounting brackets and modules if equipped. - Remove new control module from its packaging and check the service number to make sure it is the same as the defective control module. - PROM removal. Refer to PROM (MEM-CAL) replacement. NOTE Replacement control module is supplied without a PROM, so care should be used when removing it from the defective control module, because it will be reused in the new control module. INSTALL/CONNECT - Mounting brackets and modules if equipped. - Control module harness connectors. - VSS buffer connector and rotate control module to ease installation. - Control module into mounting bracket. - Mounting screw. - Hush panel if equipped. - Passenger side kick panel. Door Jamb Switch Door Switch: Locations Door Jamb Switch On A-Pillars Page 7512 Use applicable labor time guide for labor hours. Page 5378 Figure 7 Figure 8 Figure 9 Figure 10 Page 8547 Underhood Lamp: Description and Operation Voltage for the underhood lamp is supplied by the RED (2) wire from the battery junction block through the in-line fuse and ORN (40) wire. The underhood lamp is grounded through the BLK (150) wire. When the hood is raised, a mercury switch within the lamp assembly closes, completing the ground path; this allows the lamp to light. Page 6092 Blower Noise BLOWER NOISE A constant air rush noise is typical of all heater systems when operating on "HIGH" blower. Some systems and modes may be louder than others. If possible, check a similar vehicle to determine whether the noise Is typical or excessive. For diagnosis of excessive blower noise, refer to accompanying figures. Page 7623 Figure 7 Figure 8 Figure 9 Figure 10 Page 3411 SERVICE PARTS INFORMATION WARRANTY INFORMATION Engine - Block Heater Leaks Engine Block Heater: All Technical Service Bulletins Engine - Block Heater Leaks Number: 92-159-9E Section: 9E Date: APRIL 1992 Corporate Bulletin No.: 266201 ASE No.: A7 Subject: ENGINE BLOCK HEATER LEAKS Model and Year: 1976-92 LIGHT DUTY TRUCKS Some owners of 1976-1992 light duty truck engines may experience a leaking condition from the engine block heater. This condition may be caused by the block heater losing torque because the yoke, which secures the block heater, has cracked. This could cause a loss of engine coolant. The block heater brass yoke may crack due to stress corrosion where it contacts the stainless steel crossbar. The yoke is stressed or cracked from over torquing the hold down screw (Figure 1, "6"). Corrosion in the stressed area is accelerated due to the dissimilar metals. To correct this condition, a redesigned block heater should be installed. The yoke material (Figure 1 "3") of the block heater was changed from brass to stainless steel. The stainless steel is a higher strength material which reduces the possibility of stress corrosion and galvanic potential. SERVICE PROCEDURE: Follow the "ENGINE BLOCK HEATER REPLACEMENT" instructions in section 9E ENGINE BLOCK HEATER of the appropriate Service Manual. CAUTION: The gasket "O" ring seals between the block heater and the block. Excessive tightening is not necessary. The torque specification is 1.6 - 2.2 N-m (15.0 - 20.0 lbs.in.) The revised engine block heater (P/N 10154624) can be used in any light duty truck, gas or diesel engine, where an engine block heater is used. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION Qty/Veh 10154624 Engine Block Heater 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Diagram Information and Instructions Battery Cable: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 7544 Cruise Control Switch: Service and Repair Fig. 40 Mode control replacement 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect mode control connector from main harness connector and attach a suitable length of flexible wire to mode control harness. 3. Tape joint between wire and control harness to aid removal, then remove control assembly as shown in Fig. 40. 4. Reverse procedure to install. Page 5102 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 6920 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7640 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 72 Symbol Identification Page 3748 [321] USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [322] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [323] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [324] Spark knock. USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [325] Spark knock. USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [326] Tip-in hesitation, stall, CODES 23, 25, 33, or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [327] CODES 23, 25, 33, 34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [328] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/ man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [329] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/ man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [330] CODES 23, 25, 33, 34, driveability and stalling (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [331] Code 23, 25, 33, 34, driveability and stalling. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [332] FOR USE WITH MODEL C1 TRUCKS - USE 16121162 (SCAN I.D. = 3511). FOR USE WITH MODEL C2, K, K2, AND K1000 TRUCKS USE 16121166 (SCAN I.D. = 3521). [333] Surge on acceleration and/or at road load speeds, false "Service Engine Soon" light (CODE 32), poor driveability during warm up, Detonation under load (G052). [334] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [335] [Cold engine extended crank. USE 16181871 (SCAN I.D. = 0864) FOR COLD START STALL. USE 16181867 (SCAN I.D. = 0854) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [336] Engine does not stay running on initial cold start and chuggle at 35-45 MPH with TCC engaged. New MEM-CAL may affect fuel economy. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH SCANNER ID 5644 BUT A BCC OF A] [337] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [338] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [339] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [340] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. Page 1336 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 1245 Brake Bleeding: Fundamentals and Basics BENCH BLEEDING Why A master-cylinder will develop little or no pressure if air is trapped in cylinder bore. Normal brake bleeding will not remove air trapped within the master-cylinder. How Clamp the master-cylinder securely in a vice. It is usually best to clamp the side of the vice onto the flat surface that is used to secure the master-cylinder to the brake booster. There are two basic methods for bleeding master-cylinder, one utilizes stroking the master-cylinder to expel air from the cylinder bore while the other utilizes a large syringe to backflush fluid from the outlet ports to the reservoir. Stroking Fill the master-cylinder with clean brake fluid. - The brake line fittings on the master-cylinder should be capped or plugged. NOTE: Special "bench bleeding" plastic fittings are available which allow for recirculating the brake fluid back into the reservoir. - Using a dull object, slowly stroke the master-cylinder piston, air and brake fluid will be expelled from the brake line fittings. Prior to releasing the piston plug or cap the outlet ports. - Repeat this procedure 8-10 times or until no air is emitted from the outlet ports. - When finished, cap the outlet ports and install the master-cylinder. Syringe Fill the syringe (one especially designed for brake bleeding) with clean brake fluid. - Insert the end of the syringe into one of the outlet ports on the master-cylinder. - Slowly compress the syringe and back flush the brake fluid through the master-cylinder. - A combination of air and brake fluid will be emitted from the inlet port in the fluid reservoir. - Repeat this procedure until only brake fluid is emitted into the reservoir. Cap the outlet ports and install the master-cylinder. Locations Combination Switch: Locations LH Side Of Instrument Panel. On Steering Column Applicable to: Except Bravada Page 7441 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot Pilot Bearing: All Technical Service Bulletins M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot BULLETIN NUMBER: 92-7B-149A SECTION: 7B Manual Transmission NUMBER: 1 CORPORATE REFERENCE NUMBER: 2672O1R DATE: August 1993 SUBJECT: NEUTRAL GEAR RATTLE (REPLACE CLUTCH DISK, PROM AND PILOT BUSHING) MODELS: 1990-92 C/K AND 1990-92 S/T WITH 4.3L AND 5 SPEED MANUAL TRANSMISSION This bulletin cancels and replaces Truck Bulletin 92-7B-149 (corp. # 267201R) dated December 1992, and is being revised to add the 1992 model year S/T Trucks with 4.3L engines (RPO LB4) and to add the "Detonation and Neutral Gear Rattle Proms" section. CONDITION Some owners of 1990-92 C/K and 1990-92 S/T Trucks with 4.3L engines (RPO LB4) and 5-speed manual transmission (RPO's MG5, MY2) may comment that the transmission rattles when in neutral with their foot off the clutch pedal and the engine at idle. The customer may describe the rattle as loose bearings. CAUSE This rattle noise is created when the turning transmission gears contact against each other. The contact is created by the firing impulses of the engine which causes rapid acceleration and deceleration of the individual gears. CORRECTION This condition may be corrected by the installation of the following parts: - A revised clutch driven disc which features a live degree neutral stage. This neutral stage helps to smooth the rapid acceleration and deceleration of the individual transmission gears. - A revised PROM which raises engine idle speed to 650 RPM on C/K and 700 RPM on S/T. This increase in idle speed helps to smooth the engine firing pulses. - A clutch pilot bearing rather than a clutch pilot bushing. This bearing helps to isolate the transmission from the engine idle acceleration/deceleration. SERVICE PROCEDURE Important Incorrect engine idle can contribute to neutral gear rattle. Before installing the parts listed in this bulletin, refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 2, Driveability Symptoms "Rough, Unstable or Incorrect Idle Stalling" to verify there are no existing conditions contributing to a rough idle which may aggravate neutral gear rattle. Clutch Disc and Pilot Bearing Replacement: Refer to the appropriate year and model Service manual, Section 7C "Clutch Assembly and Pilot Bearing Replacement." Important C/K trucks require pressure plate P/N 15974649 which was first used in production mid-1991. 1990 and 1991 vehicles built prior to the following VIN breakpoints require installation of P/N 15974649 unless it has already been installed in a service repair: Ft. Wayne (Z) MZ516555 Oshawa (1) M1526826 Pontiac (E) ME51G465 PROM Replacement: Refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 3 "On-Vehicle Service, PROM". Page 1798 2. Loosen engine mount through bolts (Figure 1, "B") and transmission mount to crossmember bolts and ensure the exhaust flexible hose is free to - move. - Loosen exhaust pipe/converter pipe clamp U-bolt (Figure 3). - Move U-bolt out of position. - Heat the exhaust pipe/converter connection joint to loosen the converter. Page 7358 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 4709 RETURN SPRINGS Purpose Drum brake systems maintain a constant residual pressure on the wheel cylinders. Return springs overcome this residual pressure and keep the shoes/linings from contacting the drum when not in use. Return springs also overcome the resistance encountered by the shoes/linings as they are retracted across the contact pads on the backing-plate. Return springs can be separated into two categories, shoe-to-shoe and shoe-to-anchor pin. Tools Needed To remove and install return springs, three separate tool are useful. These three tools are often combined into a single pair of "brake pliers". Return Spring Tool Shoe-to-Anchor Pin These springs are attached at the brake shoe webbing (two 90 degree bends in the shank of the spring slide through and under webbing) and hook around the anchor pin. Removal A brake spring tool is inserted over the top of the anchor pin and rotated - As you rotate the tool a notch on the bottom side of tool slides under the spring and lifts it up and over the anchor pin. - The other end of the spring should now just pull up and out of the hole in the brake shoe webbing. Locations Oil Pressure Switch (For Fuel Pump): Locations Rear Of Engine Oil Pressure Switch 4.3L Utility Aluminum Wheels - Cosmetic Damage During Balancing Wheels: Customer Interest Aluminum Wheels - Cosmetic Damage During Balancing Number: 93-197-3E Section: 3E Date: MAY 1993 Corporate Bulletin No.: 393502 ASE No.: A4 Subject: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING Model and Year: 1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V 1990-93 LUMINA APV Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Page 5894 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires M/T - Clutch Pilot Bushing and Bearings Pilot Bearing: All Technical Service Bulletins M/T - Clutch Pilot Bushing and Bearings File In Section: 7 - Transmission Bulletin No.: 46-73-02 Date: October, 1994 INFORMATION Subject: Clutch Pilot Bushings and Bearings Models: 1988-95 Chevrolet and GMC Truck Light Duty Trucks with 4.3L, 5.0L, 5.7L, 6.2L, 6.5L, 7.4L Engines and Manual Transmission A worn or damaged clutch pilot bushing or bearing, located in the end of the crankshaft, can be the cause of various clutch and transmission concerns including: ^ Noise when the clutch pedal is depressed ^ Transmission noise ^ Clutch shudder on launch ^ Difficult shifting or excessive clash into reverse A worn clutch pilot bushing will not properly support the transmission input shaft. Without sufficient support, the front of the input shaft can move out of location resulting in transmission noise or clutch shudder on engagement. A damaged clutch pilot bushing or bearing may continue to turn the transmission input shaft when the clutch is released. This rotation can then cause difficult shifting or gear clash. Anytime a transmission or clutch is removed for repair, a new clutch pilot roller bearing should be installed. The end of the transmission input shaft that contacts the pilot roller bearing should also be inspected for damage. When installing the pilot roller bearing, the chamfer or lead-in to the I.D. should be installed facing the rear of the vehicle. This chamfer will help guide the input shaft into the roller bearing. This bearing is pre-lubed with a high temperature grease and does not require additional lubrication. The bearing listed below will fit all 1988-95 4.3L, 5.OL, 5.7L, 6.2L, 6.5L, and 7.4L light duty engines. Do not use a bronze clutch pilot bushing. Parts Information P/N Description Qty 14061685 Bearing, clutch Pilot 1 Parts are currently available from GMSPO. Page 4735 The pressure bleeding equipment must be of the diaphragm type. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. Important You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Begin by attaching the pressure bleeder adaptor J 29567 to the master cylinder (Figure 1). 2. Fill the pressure bleeder tank J 29532 at least 2/3 full with Delco Supreme No. 11 Hydraulic 8rake Fluid (GM P/N 1052535) or an equivalent DOT 3 motor vehicle brake fluid. The bleeder tank must be bled each time brake fluid is added. 3. Charge the bleeder tank to 140-170 kPa (20-25 psi) and connect the hose from the bleeder tank to the bleeder adaptor. 4. Open the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (Figure 2). 5. Attach the valve pressure bleeding tools J 39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (Figure 3) and to the combination valve (Figure 4). Tighten tool J 39177 only finger tight. 6. Open the pressure bleeder tank valve. 7. Bleed each wheel in the following sequence: ^ Right rear ^ Left rear ^ Right front ^ Left front Note: Page 5275 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 3614 Knock Sensor: Testing and Inspection Electronic Spark Control (ESC) Circuit Check Page 4755 Brake Caliper: Fundamentals and Basics Installation Notes WHEN INSTALLING CALIPERS AND PADS, REMEMBER... - Clean and lubricate caliper slide joint/pins with high temperature silicone grease: Unlike drum brakes, disc brakes do not utilize a spring to withdraw the pads/linings when the brake pedal is released. Disc brakes rely on the elasticity of the piston seals, and the unrestricted movement of the caliper slide assemblies to release the brakes. If the slide joints/pins are not cleaned and lubricated properly the disc brake linings will drag upon the release of the brake pedal. This will result in overheated brakes and premature brake wear. Disc Brake Mechanical Force Diagram NOTE: Floating calipers require free and unrestricted movement on the caliper mounting. Floating or sliding calipers have pistons only on one side of the rotor. The first part of the piston's travel forces the inner pad against the rotor, then further travel forces the movable part of the caliper to pull the outer pad against the rotor. High temperature silicone lubricant must be used. Low temperature grease can melt and contaminate the pads and rotors, or can bake into a very hard substance which binds the slides. Petroleum based grease can cause the slide boots to soften and swell. Work on one side at a time. If you forget how to reassemble the parts you can always use the other side as a model. Anti-squeal Coating - Apply an anti-squeal coating to the back side of the pads/linings. This coatings acts as an insulator to dampen high frequency vibrations that are generated during normal braking. These compounds are highly effective in preventing brake squeal. - Many professional repair shops recommend always rebuilding or replacing the calipers when replacing the brake linings, because: When the pistons are forced back into the calipers, the piston seals are dragged across any corrosion or abrasives that may be deposited on the inside of the caliper. Damage to the seals may not be initially evident. As the new brake linings begin to wear, the piston is gradually withdrawn from the caliper. Page 1694 Crankshaft Main Bearing: Specifications Bearing Undersize Availability Main bearings are available in standard size and undersizes of .001, .002, .009, .010 and .020 inch. Connecting rod bearings are available in standard size and .001 and .002 inch undersize for use with new and used standard size crankshafts and .010 and .020 inch undersize for use with reconditioned crankshafts. Page 2485 Coolant Temperature Sensor/Switch (For Computer): Description and Operation ECT Circuit (Typical) Engine Coolant Temperature Sensor PURPOSE Engine Coolant Temperature (ECT) Sensor is used to control: Exhaust Gas Recirculation (EGR) - Fuel delivery - Idle Air Control (IAC) - Ignition Control (IC) - Torque Converter Clutch (TCC) OPERATION The ECT sensor is a thermistor that is located in the engine coolant flow. Low coolant temperature sensor produces a high resistance (100,000 ohms at -40°C/-40°F). High coolant temperature, produces a low resistance (70 ohms at 130°C/266°F). The control module sends a 5.0 volt signal to the ECT through a resistor in the control module and measures the voltage. The voltage will be high when the engine is cold and low when the engine is hot. Engine coolant temperature affects most systems controlled by the control module. The control module uses information from the ECT to calculate spark advance as follows: Cold engine results in more spark advance. - Hot engine results in less spark advance. Page 4888 Fig. 8 Four Wheel Anti-lock Brake Wiring Circuit. 1992 4WD S/T Locations Power Steering Pressure Switch Wiring Page 1128 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Page 4869 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 1236 4. Install J 39177 on the combination valve (figure 2). 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described in SECTION 5. 7. Close the internal bleed valves. TIGHTEN * Internal bleed valves (A) to 7 N-m (60 lbs.In.). 8. Remove the three J 39177 Combination Valve Pressure Bleeding Tools. 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the Ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure as many times as needed to remove the remaining air in the hydraulic system. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. Page 6212 3. Install Rotor and Bearing Puller Guide J 25031 to the front head and install Puller J 8433 with Poly-V-Belt Puller Leg Set J 24092 and remove the clutch coil from the front head (Fig. 25). Clutch coil may also be removed by using rotor and bearing puller guide J 25031 with puller tool J 25287 (Fig. 26). Install or Connect 1. Place the clutch coil assembly on the neck of the front head with clutch coil terminals in line with mark described in Step 2 of the removal procedure. 2. Place the pulley rotor and bearing assembly on the neck of the front head and seat the clutch coil and pulley rotor in place using Rotor and Bearing Installer J 26271-A (Fig. 14). Before fully seating the assembly on the front head, be sure the clutch coil terminals are in proper location in relation to the compressor and that the three protrusions on the rear of the clutch coil housing align with the locator holes in the front head. 3. Install the pulley-rotor and bearing assembly retaining ring and reassemble the clutch plate and hub assembly. 4. Check to see that the clutch plate to clutch rotor air gap is 0.5-7.6mm (0.020-0.030"). Page 3896 Page 7591 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Disassembly/Assembly Power Steering Pump: Service and Repair Disassembly/Assembly Flushing Power Steering System 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return hose at pump inlet connector and plug connector port on pump. Position hose in large container. 3. While an assistant is filling reservoir with new power steering fluid, run engine at idle. turn steering wheel from stop to stop. Do not contact wheel stops or hold wheel in a corner as fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 4. Install all pipes and hoses. Fill system with new power steering fluid and bleed system as outlined under SYSTEM BLEEDING. 5. Operate engine for 15 minutes. 6. Remove pump return hose at pump inlet and plug connection on pump. While refilling reservoir, check draining fluid for contamination. If foreign material is still evident, replace all hoses, disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. Removal/Installation Fig. 22 Power Steering Pump Replacement. Except Turbo EXCEPT TURBO 1. Disconnect pressure and return hoses from power steering pump or steering gear housing, then secure ends in raised position to prevent oil drainage. Cap all open lines and fittings. 2. Remove power steering pump belt, then power steering pump attaching bolts. 3. Remove power steering pump assembly, Fig. 22. Fig. 23 Power Steering Pump Replacement. Turbo TURBO 1. Remove air cleaner duct, upper fan shroud, serpentine belt, fan and pulley. 2. Using power steering pump pulley remover tool No. J 25034-B, remove pulley. 3. Ensure pilot bolt bottoms in pump shaft by turning nut to top of pilot bolt. Hold pilot bolt and turn nut counterclockwise. 4. Raise and support vehicle. 5. Remove left wheel assembly and wheelhouse panel. Page 1497 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Page 143 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Connector C1 ECM Connector C1 Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Paint - Acid Rain Damage to Base Coat/Clear Coat Paint: All Technical Service Bulletins Paint - Acid Rain Damage to Base Coat/Clear Coat Number: 92-33-10 Section: 10 Date: NOV. 1991 Corporate Bulletin No.: 131060 ASE No.: B2 Subject: INDUSTRIAL FALLOUT/RAIL DUST DAMAGE TO BASE COAT/CLEAR COAT Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS Application: 1992 (and previous) models with Base Coat/Clear Coat Paint The following information regards the use of finesse type repairs to environmental (industrial fallout) and rail dust damage of base coat/clear coat paint finishes. Since the severity of the condition varies from area to area, PROPER DIAGNOSIS of the damage extent is CRITICAL TO THE SUCCESS OF REPAIRS. Diagnosis should be performed under high intensity fluorescent lighting, on horizontal surfaces (hood, roof, decklid) after they have been properly cleaned. INDUSTRIAL FALLOUT (ACID RAIN) There are three basic types of acid rain damage: Surface level contamination, - may be repaired by simply washing the vehicle, cleaning the surface with a wax and grease remover, neutralizing acidic residue and finesse polishing. - Clearcoat etching, - slight etching still noticeable after the above washing and finesse polishing procedure. - Basecoat etching, - severe etching beyond the clearcoat into the basecoat. PROCEDURES FOR SURFACE LEVEL CONTAMINATION REPAIRS 1. Wash the vehicle with standard car detergent and water and dry thoroughly. 2. Clean the affected area with a wax and grease remover. 3. Neutralize any left over acidic residue by cleaning the damaged areas with a mixture of baking soda and water (one tablespoon per quart of water), rinse THOROUGHLY and dry the panels completely. 4. Apply a finesse type polish with a foam pad. CLEAN AND INSPECT THE SURFACE A. If the damage has been repaired, remove any swirl marks with a dual action orbital polisher and foam pad. B. If some damage remains, proceed to step 5. SLIGHT CLEARCOAT DAMAGE - WET SANDING, FINESSE POLISHING 5. Select a small test area on a damaged panel. 6. Wet sand the damaged area with an American Grade ultra fine sandpaper of 1,500 to 2,000 grit and a rubber sponge sanding block. During the wet sand process; a. Use ample amounts of water b. Go slow to prevent removing too much clearcoat. Note: Be sure to use American Sandpaper. European Sandpaper has a "P" before the grit number and European grits do not align with American grits the majority of the time. 7. Remove the excess water with a rubber squeegee and inspect the area. A. If this has repaired the damage, continue the sanding procedure on the entire panel, apply a finesse type polish with a foam pad and remove any swirl marks with a dual action orbital polisher and foam pad. B. If (during the repair) it is suspected or observed that; - etching has penetrated into the base coat OR - too much clearcoat has been removed during sanding OR - base color is transferred to pad during polishing, Page 642 allowing the control module to make adjustments for different altitudes. The control module uses the MAP sensor to control fuel delivery and ignition timing. Test Description: Numbers below refer to circled numbers on the diagnostic chart. Important ^ Be sure to use the same diagnostic test equipment for all measurements. 1. Checks MAP sensor output voltage to the control module. This voltage, without engine running, represents a barometer reading to the control module. ^ When comparing Tech 1 "Scan" readings to a known good vehicle, it is important to compare vehicles that use a MAP sensor having the same color insert or having the same "Hot Stamped" number. 2. Applying 34 kPa (10" Hg) vacuum to the MAP sensor should cause the voltage to change. Subtract second reading from the first. Voltage value should be greater than 1.5 volts. Upon applying vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicated a faulty sensor. 3. Check vacuum hose to sensor for leaking or restriction. Be sure that no other vacuum devices are connected to the MAP hose. NOTE: Make sure electrical connector remains securely fastened. 4. Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connection. Output changes greater than .1 volt indicates a bad connector or connection. If OK replace sensor. Wiring Diagram For Code 33 - MAP Sensor Circuit (Signal Voltage High - Low Vacuum) ECM Circuit MAP Sensor Circuit (PCM) PCM Circuit Page 4120 Valve Body: Service and Repair 1. Drain and remove oil pan and remove filter and gasket. 2. Disconnect electrical connectors at valve body. 3. Remove detent spring and roller assembly from valve body and remove valve body to case bolts. 4. Remove valve body assembly while disconnecting manual control valve link from range selector inner lever and removing throttle lever bracket from TV link. 5. Reverse procedure to install. Torque bolts to 8 ft. lbs. and replenish fluid. Campaign - 02-313 Stop Delivery Notice Update Fuel Level Sensor: All Technical Service Bulletins Campaign - 02-313 Stop Delivery Notice Update ** ADMINISTRATIVE MESSAGE 01-277 CREATED ON 9/5/91 AT PAGE 1 OF 1 TO: ALL CHEVROLET DEALERS SUBJECT: STOP DELIVERY NOTICE 1992 S/T TRUCKS THIS IS WITH FURTHER REFERENCE TO THE 1992 S/T TRUCK STOP DELIVERY DCS ADMIN MESSAGE 01-258 DATED 8/22/91 SENT TO ALL CHEVROLET DEALERS. SELECT DEALERS WERE ADVISED IN DCS MESSAGE 02-313 DATED 9/5/91 OF PRODUCT CAMPAIGN 92C02 FUEL LEVER SENDER ARM/TANK INTERFERENCE. THIS DCS INCLUDED INVOLVED DEALER CODES AND INVOLVED VIN'S. ANY DEALER NOT RECEIVING DCS ADMIN MESSAGE 02-313 HAS NO INVOLVED VEHICLES ASSIGNED AND VIN'S WHICH FALL WITHIN THE ORIGINAL VIN RANGES LISTED BELOW ARE RELEASED FROM THE STOP DELIVERY. ASSEMBLY PLANT STARTING VIN ENDING VIN PONTIAC WEST N0100014 N0101228 MORAINE N2100052 N2101700 SHREVEPORT N8100014 N8101560 PLEASE COMMUNICATE THIS INFORMATION TO ALL DEALERSHIP MANAGEMENT IMMEDIATELY UPON RECEIPT. Page 439 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 4085 each repair. With the ATF in a tightly sealed container, place the container in a tub of hot water for a period of time. Then pour the ATF into the reservoir. This method works best with a low fluid level in the reservoir. Place the Transflow(R) machine in the direct sunlight with the cabinet door open to expose the reservoir to the rays of the warm sun. Flush / Flow Test Procedure Important All labor operations that include removal of the transmission from the vehicle and require the transmission oil pan or transmission side cover to be removed include labor time to flush the transmission oil cooler system. Refer to SI for Automatic Transmission Oil Cooler Flushing and Flow Test J 45096 for the appropriate procedure. Important The J 45096 can be used to flush the transmission oil cooler system on an Allison equipped vehicle, but the flow meter should not be utilized. Refer to SI for Automatic Transmission Oil Cooler Flushing and Flow Test J 45096 for the appropriate flow check procedure. Machine Displays After completion of the flush and flow test, the following information is to be recorded on the repair order. This information is displayed on the Transmission Cooling System Service Tool, J 45096, Transflow(R) machine when the dial is in the code position. - Tested flow rate (displayed in Gallons Per Minute (GPM) - Temperature (displayed is degrees Fahrenheit) - Cycle number (a number) - Seven digit Alpha/Numeric flow code (i.e. A10DFB2) Warranty Information Important All labor operations that include removal of the transmission from the vehicle include labor time to flush the transmission oil cooler system. Performing a transmission oil cooling system flush and flow test will use between 4.7-7.5 L (5-8 qts) of DEXRON(R)VI transmission fluid. The amount Page 2756 EGR AND EVRV SOLENOID 4.3 L Page 1354 Coolant Level Indicator Lamp: Service and Repair This lamp will be illuminated when engine coolant level in the radiator drops below a pre-determined level. To turn lamp "OFF," check cooling system, then add coolant to bring system to proper level. Page 7962 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Page 2028 1. Disconnect battery. 2. Drain coolant. 3. Remove fan shroud. 4. Remove accessory drive belt. 5. Remove fan. 6. Remove the water pump. 7. Remove crankshaft pulley and harmonic balancer. 8. Remove transmission torque converter cover. Let it lie on top of exhaust crossover pipe. 9. Drop the oil pan by leaving the rear two nuts on the crankshaft seal studs about 1/4 inch from tight. The two studs will stabilize the oil pan and the oil will not have to be drained. 10. Remove the front cover. 11. It is recommended that the engine be turned over by hand so the crankshaft and camshaft sprocket timing marks are dot to dot. 12. Loosen the small diameter balance shaft gear bolt. This is the driven gear and has a TORX drive bolt. 13. Remove the camshaft sprocket by taking off the lock nut first, then the two bolts. 14. Remove the large diameter balance shaft (drive) gear. 15. Remove the small diameter balance shaft driven gear. 16. Clean all sealing surfaces, removing all old gasket material. Installation of new matched set balance shaft gears: 1. Install driven gear (small diameter gear) and bolt finger tight. 2. Install and align drive gear dot to dot with timing mark of the driven gear. 3. Install drive gear stud to 16 Nm (12 lb.ft.) to ensure the shoulder of the stud is below the counter bore in the gear. 4. Install camshaft sprocket and chain. Ensure their timing is correct. If the camshaft and crankshaft have not been disturbed, the crankshaft and camshaft sprockets should be dot to dot. 5. Install the camshaft sprocket nut and bolts. Torque to 28 Nm (21 lb.ft.). 6. Torque driven balance shaft gear bolt to 20 Nm (15 lb.ft.) plus an additional 35° using a J 3660 degree meter, torque driver. 7. At this point, the gear change is complete. Follow the removal steps in reverse order to install the remaining components. Consult the service manual for torque specifications. CORRECTION II. The following steps should be followed to diagnose the detonation type rattle noise which occurs between 2000 - 2500 RPM under load (condition II): 1. Ensure the ESC (Electronic Spark Control) system is working properly. Refer to the ELECTRONIC SPARK CONTROL section of the LIGHT DUTY TRUCK FUEL AND EMISSIONS section of the service manual. This section includes an "ELECTRONIC SPARK CONTROL SYSTEM CHECK" with a fault tree for the 4.3L CPI engine. 2. Operate the vehicle with premium fuel. If the noise is eliminated, the noise is not coming from the balance shaft rear needle bearing. Refer to the DRIVEABILITY SYMPTOMS section of the LIGHT DUTY TRUCK FUEL AND EMISSIONS service manual. BRAVADA ONLY: Refer to Bravada service manual section 6E. 3. If the ESC system is functioning properly and the noise is still audible using premium fuel, the source of the noise is most probably the rear Page 6191 3. Using a center punch with a 45° angle point, stake 1.1-1.4mm (0.045-0.055" deep) the bearing in three places 120° apart as shown in Figure 12, but do not stake too deeply to avoid distorting the outer race of the bearing. 4. Replace rotor and bearing assembly. On-Vehicle A. Position the Rotor and Bearing assembly on the front head. B. With Rotor & Bearing Installer J 26271-A (without driver handle) in position and Rotor and Bearing assembly aligned with the Front Head as shown in Figure 14, drive the assembly part way onto the head. C. Plug clutch coil connector onto Clutch Coil. D. Position the Clutch Coil so the three (3) locating tabs will align with the holes in the head and continue to drive the Rotor and Bearing assembly onto the front head. E. Install the retainer ring (Fig. 9). F. Reassemble the Clutch Plate and Hub with the shaft key onto the shaft with Installer J 9401-B until 0.5-7.6mm (0.20-0.030") air gap is obtained. G. Install shaft lock nut. Torque to 14 N-m (10 lb.ft.). On-Bench Page 5304 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Page 5883 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Page 92 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 4976 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 7239 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 4943 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 6184 3. Pulley (6) and bearing (5) to shaft (38) with J 8092 and J 9481-A. 4. Retainer ring (4) to pulley (6) and bearing (5). 5. Pulley retainer ring (3) with J 6435. 6. Clutch plate and hub assembly (2). Page 7686 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 7327 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 6903 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 6695 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Engine - Overheating Diagnostic Tip Fan Shroud: Technical Service Bulletins Engine - Overheating Diagnostic Tip FILE IN SECTION: 6 - Engine BULLETIN NO.: 56-62-01 DATE: July, 1995 SUBJECT: Engine Overheat Resulting from Repositioning Fan in Shroud MODELS: 1990-95 Chevrolet and GMC Truck Light & Medium Duty Trucks Excluding Vans and Sport Utilities Auxiliary engine belt-driven equipment is often added to commercially owned trucks. Most service personnel recognize the potential effect this can have on water pump bearing loading. An often overlooked concern that can result from installing auxiliary belt driven equipment is the loss of some cooling system performance if the fan is repositioned fore or aft from its original factory installed position within the fan shroud. The fore/aft location of the fan within the shroud has a direct effect on how efficiently air is drawn through the radiator. A change in this relationship will often result in a report of reduced cooling system performance and possible engine overheat. Diagnosis of this type concern should start with simply asking the owner if the problem was noted prior to the installation of the auxiliary equipment. If possible, temporarily remove the add-on equipment and install the fan to its original location within the shroud and determine if this corrects the cooling problem. In some cases, a different OEM shroud and/or fan may be available that compensates for the revised placement of the fan with the added equipment. Stationary operation of engine or transmission driven equipment should be preceded by chocking the wheels and raising the hood (particularly in hot weather) to allow hot air that could be trapped under the hood of a running parked truck to escape. Page 1199 C. Parts Information D. Warranty Information 1. Vehicle Still in Warranty 2. Customer Paid' Retrofitting Costs 3. Labor Time Information Notes on Retrofit Important: Before proceeding with any retrofit, make sure you have all component Parts required on hand to perform a proper and complete repair with Minimal downtime. R-12 Removal Prior to Retrofit To prepare a system for retrofitting, the R-12 must be recovered and the system must be completely evacuated. Evacuation is necessary to insure that small amounts of R-12 and air remaining in the system are removed. This will prevent cross contamination of the two refrigerants, which could lead to reduced A/C system reliability and performance. It is very important that the specified times for waiting after recovery and evacuation not be reduced. This time is required to sufficiently remove residual R-12 from the oil in the system. A considerable amount of testing has determined that the following procedure is required to achieve satisfactory results and conform to SAE J 1661: 1. Inspect Condition of Vehicle Install the gauge set on the high and low side ports. Use normal diagnostic procedures to find the cause of the vehicle's reported condition. One of three conditions will exist with the refrigerant system: a. System pressure correct, no leaks - proceed to Step 2 (Recovery). This would normally apply when: 1. The system must be recovered/recharged for a repair to a system other than the A/C system, or 2. Where the A/C system condition did not involve leaks, but requires recovery/recharge to replace a component. b. Compressor not operating, but some charge. Leak test to find the leak, complete Step 2 (Recovery), then correct the leak before proceeding with Step 3 (Conversion port installation). c. No charge in system - proceed with the Conversion port installation in Step 3. Use the ACR4 to evacuate for 5 minutes. If the leak can be heard, repair the leak. If the leak cannot be heard, charge with 1/2 pound of R-134a. Leak test with the J 39400 Leak Detector, recover the R-134a, repair any additional leaks found, and proceed with the evacuation in Step 5. 2. Recover the R-12 from the System Notice: THIS PROCEDURE IS DIFFERENT THAN THE NORMAL (NON-RETROFIT) RECOVERY PROCEDURE. R-12 will be recovered through the HIGH SIDE SERVICE PORT ONLY, WITH THE ENGINE RUNNING. Recovery through the low side will not effectively remove the R-12 from the accumulator, resulting in possible damage to the retrofitted system. Important: Vehicle must be above 50° F (10° C) to allow for complete recovery of the R-12. If it is not, either allow it to warm up in the shop overnight, or increase the evacuation time in Step 5.a to 30 minutes. a. Connect the recovery hose from the R-12 recovery cart (ACR3) to the middle port of the A/C gauge set. Open the oil drain valve on the ACR3 cart long enough to drain the oil. Failure to do so could cause excessive amounts of oil to build up in the separator, resulting in damage to the recovery cart compressor. b. Start the engine. Leave the hood up, and the windows open. On vehicles with manual A/C controls, set the A/C controls to normal A/C mode, high blower, and temperature control to full cold. On cars with automatic A/C controls, set the temperature to 75° F, "AUTO" mode, and manually select high blower. Page 3813 Accumulator: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Accumulator Cover To Case ............................................................................................................... ................................................................................. 8 FWD Accumulator Cover To Valve Body ....... .............................................................................................................................................................. ...... 8 Page 3756 PROM - Programmable Read Only Memory: Description and Operation EPROM CAUTION: The EPROM is serviceable in some applications and can be removed for replacement. If the COMPUTER is found to be defective and needs replacement, remove the old EPROM if applicable and place into the new computer. When replacing the COMPUTER always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: The term EPROM means Erasable Programmable Read Only Memory (EPROM). The EPROM functions in the same manner as a regular PROM and is programmed with data pertaining to the vehicles weight, engine, transmission, axle ratio etc. Automotive technicians do not ERASE or PROGRAM the EPROM in the field. Instead, the EPROM is serviced in one of two manners. Some applications are soldered to the circuit board and require both the computer and EPROM to be replaced as a complete unit. Other applications allow for the EPROM only to replaced. Page 5178 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 7317 Symbol Identification Page 8022 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 6430 Page 7584 Symbol Identification Page 6056 Air Door Actuator / Motor: Description and Operation SYSTEM DESCRIPTION Control of air through the system is regulated by vacuum. At various positions of the levers on the control head, mode doors mix and direct cooled, heated, and outside air through the air ducts. VACUUM LINES Vacuum lines are molded to a connector which is attached to a vacuum control switch on the control assembly. In case of leakage or hose collapse, it will not be necessary to replace the entire harness assembly. Replacement can be made by cutting the hose and inserting a plastic connector. If the entire hose must be replaced, cut all hoses off at the connector and then attach hoses directly to the control assembly vacuum switch. VACUUM TANK During heavy acceleration, the vacuum supply from the intake manifold drops. Under load conditions a check valve in the vacuum tank maintains vacuum so that it will be available for future use. The vacuum tank is located in the engine compartment. DUCT AND OUTLETS A system of ducts and outlets directs air to the passenger compartment. In cases of poor air output, defroster, heater, AC, and vent ducts should be checked for obstructions such as leaves, dirt, or objects which may have fallen into the ducts from the passenger compartment. Page 6160 Install or Connect 1. Place the Pulley Rotor on the J 21352-A Support Block to fully support the rotor hub during bearing installation (Fig. 19). Do not support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using Puller and Bearing Installer J 9481-A with Universal Handle J 29886, drive the bearing fully into hub (Fig. 19). The Installer will apply force to the outer race of the bearing if used as shown. 3. Place Bearing Staking Guide 3 33019-1 and Bearing Staking Pin J 33019-2 in the hub bore as shown in Figure 20. Shift the rotor and bearing assembly on the J 21352-A Support Block to give full support of the hub under the staking pin location. A heavy duty rubber band may be used to hold the stake pin in the guide (Fig. 20), and the stake pin should be properly positioned in the guide after each impact on the pin. 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to, but not touching, the bearing. Stake three (3) places 120° apart as shown in Figure 21. NOTICE:, The stake metal should not contact the outer race of the bearing to prevent the possibility of distorting the outer race. Page 831 Transmission Speed Sensor: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Page 1710 For vehicles repaired under warranty use: Description Labor Op. Heater, Engine Block - Replace R4600 Use applicable labor time guide for labor hours. Service and Repair Evaporative Canister Filter: Service and Repair NOTE: NOT ALL EVAPORATIVE EMISSION CONTROL CANISTERS HAVE A SERVICEABLE FILTER. At intervals recommended, usually every 24 months or 30,000 miles, the filter on an open bottom canister should be replaced, 1. Remove all hoses from the top of the canister and mark. Remove the canister. 2. Remove the filter element by squeezing it out from under the lip surface at bottom of canister and from under retainer bar, where used. 3. Squeeze the new element under retainer bar, where used, and position it evenly around the entire bottom of the canister. Tuck the edges under the lip of canister. 4. Reinstall the canister to its original position on the vehicle, following normal service procedures. 5. Reconnect the hoses to the top of the canister, according to the labeling on top of canister. Page 8205 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 4087 Transmission Cooler: Technical Service Bulletins A/T - Water Or Coolant Contamination Information INFORMATION Bulletin No.: 08-07-30-035B Date: November 01, 2010 Subject: Information on Water or Ethylene Glycol in Transmission Fluid Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks with Automatic Transmission Supercede: This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 08-07-30-035A (Section 07 - Transmission/Transaxle). Water or ethylene glycol in automatic transmission fluid (ATF) is harmful to internal transmission components and will have a negative effect on reliability and durability of these parts. Water or ethylene glycol in ATF will also change the friction of the clutches, frequently resulting in shudder during engagement or gear changes, especially during torque converter clutch engagement. Indications of water in the ATF may include: - ATF blowing out of the transmission vent tube. - ATF may appear cloudy or, in cases of extreme contamination, have the appearance of a strawberry milkshake. - Visible water in the oil pan. - A milky white substance inside the pan area. - Spacer plate gaskets that appear to be glued to the valve body face or case. - Spacer plate gaskets that appear to be swollen or wrinkled in areas where they are not compressed. - Rust on internal transmission iron/steel components. If water in the ATF has been found and the source of the water entry has not been identified, or if a leaking in-radiator transmission oil cooler is suspected (with no evidence of cross-contamination in the coolant recovery reservoir), a simple and quick test kit is available that detects the presence of ethylene glycol in ATF. The "Gly-Tek" test kit, available from the Nelco Company, should be obtained and the ATF tested to make an accurate decision on the need for radiator replacement. This can help to prevent customer comebacks if the in-radiator transmission oil cooler is leaking and reduce repair expenses by avoiding radiator replacement if the cooler is not leaking. These test kits can be obtained from: Nelco Company Test kits can be ordered by phone or through the website listed above. Orders are shipped standard delivery time but can be shipped on a next day delivery basis for an extra charge. One test kit will complete 10 individual fluid sample tests. For vehicles repaired under warranty, the cost of the complete test kit plus shipping charges should be divided by 10 and submitted on the warranty claim as a net item. The transmission should be repaired or replaced based on the normal cost comparison procedure. Important If water or coolant is found in the transmission, the following components MUST be replaced. - Replace all of the rubber-type seals. - Replace all of the composition-faced clutch plates and/or bands. - Replace all of the nylon parts. - Replace the torque converter. - Thoroughly clean and rebuild the transmission, using new gaskets and oil filter. Important The following steps must be completed when repairing or replacing. Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052F- Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow. - Thoroughly inspect the engine cooling system and hoses and clean/repair as necessary. Locations Horn Relay Installation Page 5242 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Left Side Knock Sensor Engine Wiring, LH Side Page 320 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 7320 Cruise Control Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 8369 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 8295 Map Light: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 3153 Thermostatic Air Cleaner: Testing and Inspection SYSTEM CHECK Results of Incorrect THERMAC Operation May Cause hesitation during warm up, check for: ^ Heat stove tube disconnected. ^ Damper door does not move (stuck closed). ^ Missing air cleaner to TBI unit seal. ^ Missing air cleaner cover seal or loose cover. ^ Loose air cleaner. Lack of power, sluggish, pinging or spongy, on a hot engine check for: ^ Damper door does not open to outside air. Air Cleaner Functional Check 1. Remove air cleaner assembly and cool to below 40 degrees FAHRENHEIT. The damper should be closed to outside air. 2. Check for presence and condition of air cleaner to throttle body gasket. 3. Reinstall air cleaner and be sure heat stove tube is connected at air cleaner snorkel and exhaust manifold. 4. Start engine. Watch damper door in air cleaner snorkel. As air cleaner warms up, damper door should open slowly to outside air. 5. If air cleaner fails to operate as described, be sure calibrated spring is properly installed and damper is not binding. If OK, replace wax pellet actuator assembly. Page 1202 Select and install the proper R-134a fittings (shown in Figure 4) from the chart below, based on how the ACR4 couplers will attach. Also, remember to check for proper hood clearance with the conversion fittings. Try the straight fittings first. The two-piece high side fitting is used when the existing fitting is screwed into the pipe fitting (some 1992, and nearly all 1993 models, use these fittings). Use the 90° elbow if the straight fitting does not allow the ACR4 couplers to connect. Fitting Type High Side Low Side Straight 52467941 52467943 Straight Two-piece 52467324 N/A 90° Elbow 52469054 52469055 The fittings should be installed as follows: a. Remove the caps from the R-12 fittings. Remove any dirt or grease from the port threads using the thread cleaning wire brush, J 41265. Inspect the fittings for thread damage. If any damage is found, use the port thread restorer (J 41266 low side, J 41267 high side) to repair the thread. For the two-piece fitting, remove the existing R-12 fitting and discard it. Use tool J 38704A (previously released, not part of the above kit) to remove the fitting. Make sure to hold the line securely to prevent damage when removing the existing fitting. If the fitting cannot be removed easily, use the saddle clamp valve listed below and seal the R-12 port and cap permanently. b. Install the selected fitting onto the existing R-12 fitting. Leave the valve core in the straight fittings, and remove the valve core when using the 90° fittings. If the valve cores need to be removed at a later time, they can be removed with the straight conversion fittings in place. On the low side straight fitting, use the J 34611-A tool to remove the core pin in the conversion fitting, then remove the core valve from the original R-12 fitting. Always recover the charge before valve core removal. Page 5291 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Recall 93V008000: Engine Cooling Fan Blade Breaks Fan Blade: Recalls Recall 93V008000: Engine Cooling Fan Blade Breaks The engine cooling fan blades break as a result of fatigue and/or vehicle induced stress. If the blade breakage occurs while the hood is open, a person working under the hood or in the vicinity of the vehicle could be struck and injured by the blade segment. Install a newly designed fan assembly. System: Engine. Vehicle description: Light trucks with 2.5L engines without air conditioning. Page 379 Symbol Identification A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 3943 Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Page 5731 Remove or Disconnect (Figures 1, 2, 3, 5, 6, and 7): Tool Required: J23028-O1 Coil Spring Remover and Installer Raise the vehicle on a hoist so that the control arms hang free. 1. Remove the shock absorber bolts (38) from the shock absorber pivot (39) (Figure 2). a. Push the shock absorber up through the lower control arm (40) and into the spring (37) (Figure 2). b. Cradle the inner control arm bushings using J 23028-01 (Coil Spring Remover and Installer) secured to the end of a suitable jack (Figure 5). 2. Disconnect the stabilizer shaft (53) from the lower control arm (Figure 3). a. Raise the jack to remove the tension on the lower control arm pivot bolts (72 and 77) (Figure 1). b. Secure the lower control arm (40) with a chain around the spring (37) and through the control arm (Figure 1). 3. Remove the lower control arm pivots bolts (72 and 77) and nuts (71 and 78) from the lower control arm (40) (Figure 1). IMPORTANT: Do not force the lower control arm (40) and ball joint (69) in order to remove the coil spring (Figure 1). 4. Remove the coil spring (37) and the insulator (73) from the coil spring (Figure 1). - Position the coil spring (37) properly for easy removal. Page 4825 Fig. 5 Bracket Removal & Installation Page 6002 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Page 7289 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 5616 Fig. 3 Return tube removal Fig. 4 Control valve assembly removal Fig. 5 Driveshaft retaining ring removal Fig. 6 Driveshaft & bearing removal Fig. 7 Thrust plate retaining ring removal Automatic Transmission Neutral Safety Switch: Service and Repair Automatic Transmission 1. Remove battery ground cable. 2. Remove lower insulator panel. 3. Remove neutral start switch electrical connector. 4. Remove neutral start switch. 5. Reverse procedure to install, noting the following: a. Align actuator on the switch with holes in shift tube. b. Press down on front of switch until tangs snap into rectangular holes in the steering column jacket. c. Adjust switch by moving the gear selector to park. Page 2145 Compression Check: Testing and Inspection COMPRESSION CHECK - Disconnect the primary terminal from the ignition coil. - Remove all spark plugs. - Block the throttle plate wide open. - Make sure the battery is fully charged. Starting with the compression gauge at zero, crank the engine through four compression strokes (four "puffs"). - Make the compression check at each cylinder and record each reading. - If some cylinders have low compression, inject 15 ml (one table spoon, or 3 squirts from a pump type oil can) of engine oil into the combustion chamber through the spark plug hole. - Minimum compression recorded in any one cylinder should not be less than 70 percent of the highest cylinder, and no cylinder should read less than 690 kPa (100 psi). Normal Compression: Compression builds up quickly and evenly to specified compression on each cylinder. Piston Rings Leaking: Compression low on first stroke, tends to build up on following strokes, but does not reach normal. Improves considerably with addition of oil. Valves Leaking: Low on first stroke. Does not tend to build up on following strokes. Does not improve much with addition of oil. Head Gasket Leakage: If two adjacent cylinder have lower than normal compression, and injecting oil into cylinders does not increase the compression, the cause may be a head gasket leak between the cylinders. Page 6254 Inspection Seals should not be reused. Always use a new specification service seal kit on rebuild. Care should be taken to prevent damage to the lip of the one piece seal. Make sure that the Seal Seat and Seal Lip are free of lint and dirt that could damage the seal surface or prevent sealing. On-Vehicle Install or Connect 1. Dip the new seal O-ring in clean 525 viscosity refrigerant oil and assemble onto O-ring Installer J 33011 (Fig. 28). 2. Insert the O-ring Installer J 33011 completely down into the compressor neck until the Installer "bottoms". Lower the moveable slide of the O-ring Installer to release the O-ring into the seal seat O-ring lower groove. (The compressor neck top groove is for the shaft seal retainer ring.) Rotate the Installer to seat the O-ring and remove the Installer. 3. Prepare Lip Seal: - Assemble Lip Seal to Seal Installer, J 23128-A, (Fig. 28). The printed/stamped steel case side of Lip Seal must be engaged with knurled tangs of installer so that flared-out side of Lip Seal is facing and installed towards the compressor. 4. Install Lip Seal: - Place Seal Protector J 34614 over end of compressor shaft and slide new seal onto the shaft until it stops (Fig 28). Disengage installer from seal and remove seal protector from compressor shaft. NOTICE:, Handling and care of seal protector is important. If seal protector is nicked or the bottom flared, the new seal may be damaged during installation. 5. Install the new seal seat retainer ring with its flat side against the Seal Seat, using Snap-Ring Pliers J 5403 (Fig 29). Use the sleeve from O-ring Installer J 33011 to press in on the seal seat retainer ring so that it snaps into its groove. 6. Evacuate and charge system with 1 lb. refrigerant. Temporarily install the shaft nut and, with the compressor in horizontal position, rotate the compressor shaft in normal direction of rotation several times. Leak test the seal. Recover refrigerant and repair as necessary. Remove, discard and later replace the shaft nut. 7. Remove any excess oil, resulting from installing the new seal parts, from the shaft and inside the compressor neck. 8. Install the Clutch Plate and Hub assembly. 9. Reinstall compressor belt and tighten Bracketry. 10. Evacuate and Charge the Refrigerant System. Off-Vehicle Page 91 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 6064 Air Door Actuator / Motor: Service and Repair Plenum Side Vent Actuator Replacement Plenum Side Vent Actuator REMOVE OR DISCONNECT 1. Front door sill plate. 2. Cowl side vent cover. 3. Vacuum line from the actuator (63). 4. Valve assembly (66). 5. Actuator (63). INSTALL OR CONNECT 1. Actuator (63). 2. Valve assembly (66) to the vehicle. 3. Vacuum line to the actuator (63). 4. Cowl side vent cover. 5. Front door sill plate. Page 1522 A. Obtain a straight edge approximately 8-9 inches long and, while holding it in two hands, as shown in the attached illustration, place it on the inboard mounting surface of the wheel and try to rock it up and down. B. Repeat the above procedure on three or four different positions on the wheel inboard mounting surface. C. The outer ring of the mounting surface is normally raised above everything inside it. If a wheel mounting surface has been bent on a tire changer, it will be raised above the outer ring and the straight edge will rock on this "raised" portion. D. If a bent wheel is found, it must be replaced. Page 7246 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 2958 MAP Circuit (VCM) VCM Circuit Page 4022 Fig. 6 TV Cable Adjustment. Astro, Safari & S/T-10/15 Gasoline Engine 1. Depress and hold metal readjust tab. Move slider back through fitting in direction away from throttle body until slider stops against fitting, Figs. 4 through 6. 2. Release metal readjust tab. 3. Open throttle lever to full throttle stop position to automatically adjust cable, then release throttle lever. 4. Check cable for proper operation. If sticking or binding occurs, check system as outlined in TV SYSTEM DIAGNOSIS. Fig. 7 TV Cable Adjustment Diesel Engine Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F With A/C Blower Motor Resistor: Service and Repair With A/C Evaporator And Blower Assembly Component View NOTE: The blower resistor is mounted on the blower side of the blower-evaporator case. REMOVE OR DISCONNECT 1. Electrical connectors, as necessary. 2. Screws (34). 3. Resistor (35). INSTALL OR CONNECT 1. Resistor (35). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 2. Screws (34). 3. Electrical connectors, as necessary. - Check circuit operation. Page 6602 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Locations Electronic Control Module Page 7228 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 8511 Turn Signal Switch: Service and Repair Fig. 6 Compressing Lock Plate 1. Disconnect battery ground cable. 2. Remove steering wheel as outlined under STEERING WHEEL & HORN SOUNDER. 3. Using a screwdriver, pry cover from lock plate. 4. Using lock plate compressing tool No. J-23653, compress lock plate and pry retaining ring from groove on shaft, Fig. 6. Slowly release lock plate compressing tool, remove tool and lock plate from shaft end. 5. Slide canceling cam and upper bearing preload spring from end of shaft. 6. Remove turn signal (multi-function) lever. 7. Remove hazard warning knob retaining screw, button, spring and knob. 8. Remove pivot arm. 9. Remove switch retaining screws and pull switch up from column, guiding wire harness through column. 10. Reverse procedure to install. Page 5080 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Front Wheel Speed Sensor Wheel Speed Sensor: Service and Repair Front Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Disconnect brake caliper assembly and position aside. 3. On two wheel drive models, remove hub and rotor assembly. 4. On four wheel drive models, remove rotor, then hub and bearing assembly. 5. On all models, disconnect wheel sensor electrical connector. 5. Remove sensor wire form upper control arm clip. 6. Remove sensor and splash shield assembly attaching bolts, then remove sensor. 7. Reverse procedure to install. On two wheel drive models, torque sensor and splash shield assembly to steering knuckle attaching bolts to 11 ft. lbs. Hydraulic System Bleeding Brake Bleeding: Service and Repair Hydraulic System Bleeding Manual Bleeding 1. If vehicle is equipped with power brakes, remove vacuum reserve by applying brakes several times with engine off. 2. Fill master cylinder reservoirs with suitable brake fluid. Be sure to always keep master cylinder reservoirs at least half full during entire bleeding procedure. 3. If master cylinder is suspected to have air in the bore, it must be bled first, as follows: a. Disconnect forward brake pipe connection at master cylinder. b. Allow brake fluid to fill master cylinder bore until it begins to flow from forward pipe connector port. c. Connect and tighten forward brake pipe at master cylinder. d. Depress brake pedal slowly one time and hold, then loosen forward brake pipe connection at master cylinder to purge air from bore. Tighten connection, then release brake pedal slowly. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged from bore. e. Bleed rear bore of master cylinder as front bore was bled. 4. Bleed right rear brake as follows: a. Depress brake pedal slowly one time and hold. b. Loosen bleeder valve to purge air from brake, then tighten bleeder valve and slowly release pedal. c. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged. 5. Bleed left rear, right front, and left front brakes, in that order, using same method as for right rear brake. 6. Check brake operation and ensure pedal is firm. Also check master cylinder fluid level and add fluid as necessary. 7. Turn off brake warning light by applying moderate pressure to brake pedal several times. 8. Road test vehicle. Fig. 1 Installing Pressure Bleeder Adapter Pressure Bleeding 1. Loosen, then slightly retighten bleeder valves at all four wheels. Repair any broken, stripped or frozen valves at this time. 2. Using a diaphragm type pressure bleeder, install suitable bleeder adapter to master cylinder, Fig. 1. 3. Charge bleeder ball to 20-25 psi, then depress and hold valve stem on combination valve. 4. Connect pressure bleeder line to adapter. 5. Open line valve on pressure bleeder, then depress bleed-off valve on adapter until a small amount of brake fluid is released. 6. Raise and support vehicle. 7. Bleed right rear, left rear, right front and left front brakes, in that order. 8. Place transparent tube over bleeder valve, then allow tube to hang down into transparent container. Ensure end of tube is submerged in clean brake fluid. 9. Open bleeder valve 1/2 to 3/4 turn and allow fluid to flow into container until all air is purged from line. Flushing Hydraulic System If brake fluid is old, rusty or contaminated, or whenever new parts are installed in the hydraulic system, the system must be flushed. Bleed brakes, allowing at least one quart of clean brake fluid to pass through system. Any rubber parts in hydraulic system which were exposed to contaminated fluid must be replaced. Page 6226 Removing The Shaft Nut - Compressor to J 9396. Secure with thumb screws. 1. Shaft nut (1) with 9399-A. - Hold the clutch plate and Hub assembly (2) with J 25030-A. 2. Clutch plate and hub assembly. Removing The Clutch Plate And Hub Assembly - Thread J 9401-B into the clutch plate and hub (2) (figure 3). - Hold the body of J 9401-B with a wrench and tighten the center screw into the remover body. 2. Shaft key (36). - Retain the shaft key (36) if usable. Inspect All parts and replace as necessary. Install or Connect Page 5433 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 7031 PAINT air dry only Note: Only items marked with an asterisk are "add" conditions to the Major Operation being performed. Removal time for all other items listed is included in the refinish time. LIGHT DUTY TRUCKS C/K TRUCKS Grille Front bumper filler panel Antenna Tail lamps Door edge guards Metal wheel opening moldings *Roof marker lamps "Luggage rack *West coast style mirrors "Stripes Emblems/decals if necessary Swing out windows/seals Tail gate handle bezel S/T TRUCKS Windshield molding Bumper filler panels, Ft./Rr. Wiper arms Antenna Wheel opening moldings Cowl vent grille Door edge guards Side view mirrors Tail lamps *Wind deflector Rear Window (Jimmy) *Luggage rack *Stripes Emblems/decals if necessary Swing out windows/seals *Spare tire carrier and latch-external mount (Jimmy) M/L VANS Windshield molding Wheel opening moldings Headlamp bezels Antenna Tail lamps Door edge guards *Luggage rack *Stripes Emblems/decals if necessary R/V TRUCKS Wiper arms Cowl vent grille Antenna Tail lamps Hood ornaments Wheel opening moldings Side view mirrors Grille and headlamp bezels Page 6601 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 7284 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7800 Driver Information Center (DIC): Symptom Related Diagnostic Procedures Check Gages Indicator Does Not Light With High Coolant Temperature - Gage OK Check Gages Indicator Does Not Light With Low Oil Pressure - Gage OK Cluster Display Does Not Dim With Lights On Cluster Display Does Not Light Page 3011 Vehicle Speed Sensor: Description and Operation 2 Wheel Drive (Manual Transmission) VSS 2WD Manual Transmission 2 Wheel Drive (Automatic Transmission) VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 4 Wheel Drive or All Wheel Drive VSS 4WD Or AWD PURPOSE The Vehicle Speed Sensor (VSS) provides information to the control module for control of: Transmission Torque Converter8Clutch (TCC) - Speedometer - Odometer Page 958 Spark Plug: Specifications Spark Plugs 22 ft.lb Page 4545 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Oil Pressure Gauge - Incorrect or Erratic Readings Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Incorrect or Erratic Readings Number: 93-57-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268304 ASE No.: A1, A8 Subject: INCORRECT OR ERRATIC OIL PRESSURE READINGS Model and Year: 1990-93 ALL LIGHT DUTY TRUCKS Owners of some 1990 through 1993 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. Service Procedure: Check for normal causes of high oil pressure gauge readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure below. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. connect the negative battery cable. Parts Information: Page 3882 Page 2562 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Page 6286 inserted through the mode indicator. (Fig.3) 13. Torque the housing, baseplate and blower switch mounting screws to 6-10 lbs.in. 14. If necessary, install new knobs on mode, temperature, and blower controls to ensure proper retention. SERVICE PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: LABOR OPERATION DESCRIPTION D0362 R & R HVAC control ADD: Replace housing Use applicable labor time guide for labor hours. Page 764 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 1613 Torque adjustable lash service studs to 47 N-m (35 lbs.ft.). Install rocker arms P/N 10066063. Install ball P/N 14091813 and nut P/N 477212. Using the valve lash procedure for adjustable lash valvetrain (pressed-in rocker arm stud procedure) outlined in the service manual, lash the valves to 1.75 turns down from zero lash (not 1 turn). NOTE: 1991 net lash LB4 engines may be converted to an adjustable lash system using these same part numbers. However, if the 1991 lifters are retained, the valves should be lashed to 1 turn down from zero lash. SERVICE PARTS INFORMATION: Parts are currently available from GMSPO. WARRANTY INFORMATION: Note: Labor operations are coded to base vehicle coverages in the warranty system. Page 5386 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 6696 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Recall 93V008000: Cooling Fan Replacement Fan Blade: Recalls Recall 93V008000: Cooling Fan Replacement THE ENGINE COOLING FAN BLADES BREAK AS A RESULT OF FATIGUE AND/OR VEHICLE INDUCED STRESS. IF THE BLADE BREAKAGE OCCURS WHILE THE HOOD IS OPEN, A PERSON WORKING UNDER THE HOOD OR IN THE VICINITY OF THE VEHICLE COULD BE STRUCK AND INJURED BY THE BLADE SEGMENT. INSTALL A NEWLY DESIGNED FAN ASSEMBLY. SYSTEM: ENGINE. VEHICLE DESCRIPTION: LIGHT TRUCKS WITH 2.5 L ENGINES WITHOUT AIR CONDITIONING. 1989 CHEVROLET TRUCK S10 1989 GMC S15 1990 CHEVROLET TRUCK S10 1990 GMC S15 1991 CHEVROLET TRUCK S10 1991 GMC S15 1992 CHEVROLET TRUCK S10 1992 GMC S15 Page 2696 Spark Plug Wire: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Testing and Inspection Voltage Regulator: Testing and Inspection Regulator In Charging Circuit 1. Connect a suitable voltmeter and fast charger to 12 volt battery. 2. Connect regulator and test light, observing battery polarity. Test Light should be on. 3. Turn on the fast charger and slowly increase charge rate. Observe the voltmeter and test light. 4. Test light should go out at voltage regulator setting of 13.5-16.0 volts. The test light is connected into the circuit exactly as the rotor is when the regulator is inside the alternator. The regulator shuts off the current to the test light when the regulator setting is reached. This voltage will vary with changes in temperature. Locks - Key Code Security Rules and Information Key: Technical Service Bulletins Locks - Key Code Security Rules and Information INFORMATION Bulletin No.: 10-00-89-010 Date: May 27, 2010 Subject: Key Code Security Rules and Information on GM KeyCode Look-Up Application (Canada Only) Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saturn and Saab 2002 and Prior Isuzu Attention: This bulletin has been created to address potential issues and questions regarding KeyCode security. This bulletin should be read by all parties involved in KeyCode activity, including dealer operator, partner security coordinator, sales, service and parts departments. A copy of this bulletin should be printed and maintained in the parts department for use as a reference. Important U.S. dealers should refer to Corporate Bulletin Number 10-00-89-009. Where Are Key Codes Located? General Motors provides access to KeyCodes through three sources when a vehicle is delivered to a dealer. Vehicle KeyCodes are located on the original vehicle invoice to the dealership. There is a small white bar coded tag sent with most new vehicles that also has the key code printed on it. Dealerships should make a practice of comparing the tag's keycode numbers to the keycode listed on the invoice. Any discrepancy should be reported immediately to the GM of Canada Key Code Inquiry Desk. Remember to remove the key tag prior to showing vehicles to potential customers. The third source for Key codes is through the GM KeyCode Look-Up feature within the OEConnection D2DLink application. KeyCode Look-Up currently goes back 17 previous model years from the current model year. When a vehicle is received by the dealership, care should be taken to safeguard the original vehicle invoice and KeyCode tag provided with the vehicle. Potential customers should not have access to the invoice or this KeyCode tag prior to the sale being completed. After a sale has been completed, the KeyCode information belongs to the customer and General Motors. Tip Only the original invoice contains key code information, a re-printed invoice does not. GM KeyCode Look-Up Application for GM of Canada Dealers All dealers should review the General Motors of Canada KeyCode Look-Up Policies and Procedures (Service Policy & Procedures Manual Section 3.1.6 "Replacement of VIN plates & keys"). Please note that the KeyCode Access site is restricted. Only authorized users should be using this application. Please see your Parts Manager for site authorized users. KeyCode Look-Up currently goes back 17 years from current model year. Important notes about security: - Users may not access the system from multiple computers simultaneously. - Users may only request one KeyCode at a time. - KeyCode information will only be available on the screen for 2 minutes. - Each user is personally responsible for maintaining and protecting their password. - Never share your password with others. - User Id's are suspended after 6 consecutive failed attempts. - User Id's are disabled if not used for 90 days. - Processes must be in place for regular dealership reviews. - The Parts Manager (or assigned management) must have processes in place for employee termination or life change events. Upon termination individuals access must be turned off immediately and access should be re-evaluated upon any position changes within the dealership. - If you think your password or ID security has been breached, contact Dealer Systems Support at 1-800-265-0573. Page 8063 Fig. 49 Speedometer Calibration Chart. The speedometer must be recalibrated to allow proper system operation whenever the rear axle ratio or rear tire size is changed. Calibration requires the use of a speedometer calibration service kit. When servicing the digital ratio adapter and calibrating the speedometer, do not touch the pins on the rear of the instrument cluster as immediate damage to the cluster will occur. 1. Remove instrument cluster assembly as outlined. 2. Plug connector from speedometer calibration service kit into rear of cluster, Figs. 47 and 48. 3. Momentarily touch connector leads across battery terminals noting the following: a. Service kit connector should be used a maximum of 10 times. b. It is not necessary to momentarily energize calibration system if speedometer has been previously calibrated. 4. Refer to the calibration chart Fig. 49, to determine which pins to remove from the calibration clip, Fig. 47, noting the following: a. The rectangular end of the clip is the top, and pins are numbered 1-8 from top to bottom. b. Remove proper pins by bending them back and forth with long nose pliers, taking care not to bend adjacent pins. 5. Insert calibration clip into rectangular slot in rear of cluster, Fig. 48, ensuring pins engage proper holes. 6. Reinstall cluster and check system operation. Page 8323 Map Light: Component Tests and General Diagnostics Rearview Mirror Map Light Does Not Operate Vanity Mirror Does Not Light Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Page 153 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 6236 assembly to its final position. The air gap between frictional surfaces of the clutch plate and clutch rotor should be 0.50-0.76mm (0.020-0.030"). NOTICE: If the center screw is threaded fully onto the end of the compressor shaft. or if the body of the installer is held and the center screw is rotated, the key will wedge and will break the clutch hub. 7. Remove installer J 33013-B, check for proper positioning of the shaft key (even or slightly above the clutch hub). 8. Spin the pulley rotor by hand to see that the rotor is not rubbing the clutch drive plate. Page 6141 - Mark or scribe the location of the clutch coil (8) to terminal on the compressor front head (16). 3. Clutch coil assembly (8). - Coil housing retaining ring (7) with J 6435. - Using a large screwdriver or small pry bar; pry the clutch coil away from the front head. If necessary, hand impact a blow to the screwdriver handle or pry bar to break the adhesive bond of the clutch coil to the front head. Clean Adhesive from the coil by scraping with a putty knife. - Remove any adhesive around the three locator hole areas of the front head and around the three clutch coil locator protrusions at the rear of the clutch coil housing. - Use a suitable solvent to clean the coil. Important After applying Loctite Depend, Loctite Trim and Detail Adhesive or equivalent to the coil, install all the clutch parts to the compressor. Allow 30 minutes for the adhesive to set. Install or Connect Tool Required: J 6435 External Snap Ring Pliers Adhesive Fill Guide 1. Adhesive to the clutch coil (8) - Place the clutch coil "face down" and apply the adhesive in a circular bead around the three coil locator protrusions. Page 5094 Starter Solenoid: Locations Battery ................................................................................................................................................. .......................... R/H front of engine compartment Battery Junction Block ........................................................................................................................................ Engine Compartment, on center of cowl Generator ........................................................................................ ........................................................................................................... Front of Engine Ignition Switch .............................................................................................................................................................. ......... R/H side of steering column Starter Motor ................................................................................ .............................................................................................. Lower RH side of engine C100 ............. .............................................................................................................................................................. ............................. L/H side of cowl G100 ........................................................................................... .......................................................................................................... R/H side of engine G101 .......... .............................................................................................................................................................. ........................ Above R/H headlamp S100 ........................................................................................ ................................................................................................................ Behind generator S101 ....... .............................................................................................................................................................. ................................... Behind generator S200 .................................................................................... .............................................................................. Behind L/H side of I/P, above fuse block S209 .... .............................................................................................................................................................. ... Behind L/H side of I/P, near I/P cluster Page 1148 Retrofit Requirements The customer should be reminded that there is NO requirement in the U.S. to retrofit any vehicle produced with R-12. Vehicles built with R-12 can be serviced with R-12 as long as it is available (except in certain Canadian Provinces). GM has taken steps to extend the supply of R-12 and recommends that all R-12 vehicles continue to be serviced with R-12 as long as it is available. Training Video Before doing a retrofit the first time, it is recommended that you view the Certified Plus Training Video, Program number 51010.15, "R-134a Retrofit for GM Cars and Trucks". Table of Contents A. Retrofit Procedure 1. Inspect Condition of Vehicle 2. Recover the R-12 (new method) 3. Install the service port conversion fittings 4. Install any additional parts needed 5. Evacuate and recharge with new PAG or V5 retrofit oil and R-134a 6. Install the retrofit label Platform Details Compressor Replacement Chart B. General Information 1. Performance 2. Leakage 3. Desiccant 4. Improved Cooling Performance 5. PAG or V5 Oil Compatibility 6. Refrigerant Oil Level Page 5944 A. Obtain a straight edge approximately 8-9 inches long and, while holding it in two hands, as shown in the attached illustration, place it on the inboard mounting surface of the wheel and try to rock it up and down. B. Repeat the above procedure on three or four different positions on the wheel inboard mounting surface. C. The outer ring of the mounting surface is normally raised above everything inside it. If a wheel mounting surface has been bent on a tire changer, it will be raised above the outer ring and the straight edge will rock on this "raised" portion. D. If a bent wheel is found, it must be replaced. Page 8524 Figure 7 Figure 8 Figure 9 Figure 10 Page 6091 Blower Noise Page 4333 - Use J 8614-01 to hold the pinion flange. 5. Propeller shaft to the pinion flange. 6. Bolts and retainers. - Tighten bolts to 45 Nm (33 ft. lbs.). Page 6883 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Description Labor Op. Striker and/or Support - Replace (RH) B5820 Striker and/or Support - Replace (LH) B5821 Service and Repair Timing Cover: Service and Repair 1. Remove torsional damper. 2. Remove water pump, then the upper radiator hose. 3. Remove oil pan as described under OIL PAN. 4. Remove A/C compressor and position aside. 5. Remove right side engine accessory bracket. 6. Remove front cover attaching bolts and reinforcements. 7. Remove front cover. 8. Reverse procedure to install, torquing cover bolts to specification. Locations Engine Wiring, LH Side Page 2534 allowing the control module to make adjustments for different altitudes. The control module uses the MAP sensor to control fuel delivery and ignition timing. Test Description: Numbers below refer to circled numbers on the diagnostic chart. Important ^ Be sure to use the same diagnostic test equipment for all measurements. 1. Checks MAP sensor output voltage to the control module. This voltage, without engine running, represents a barometer reading to the control module. ^ When comparing Tech 1 "Scan" readings to a known good vehicle, it is important to compare vehicles that use a MAP sensor having the same color insert or having the same "Hot Stamped" number. 2. Applying 34 kPa (10" Hg) vacuum to the MAP sensor should cause the voltage to change. Subtract second reading from the first. Voltage value should be greater than 1.5 volts. Upon applying vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicated a faulty sensor. 3. Check vacuum hose to sensor for leaking or restriction. Be sure that no other vacuum devices are connected to the MAP hose. NOTE: Make sure electrical connector remains securely fastened. 4. Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connection. Output changes greater than .1 volt indicates a bad connector or connection. If OK replace sensor. Wiring Diagram For Code 33 - MAP Sensor Circuit (Signal Voltage High - Low Vacuum) ECM Circuit MAP Sensor Circuit (PCM) PCM Circuit Page 8060 AC Delco Service Centers Page 8574 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 1583 Wheel Bearing: Adjustments Four Wheel Drive - 4WD FRONT WHEEL BEARINGS ADJUSTMENT 4 X 2 MODELS 1. Raise and support front of vehicle. 2. Remove hub dust cover, then the cotter pin. 3. While rotating wheel assembly in forward direction, torque spindle nut to specification to fully seat the bearings. 4. Loosen nut to the ``just loose'' position, then tighten the spindle nut finger tight. 5. If either spindle hole does not line up with a spindle nut slot, back off spindle nut not more than 1/2 nut flat. 6. Install new cotter pin, then measure hub endplay. Endplay should be .001-.005 inches when properly adjusted. 7. Install hub dust cover and lower vehicle. 4 X 4 MODELS These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Page 8302 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts IP Dimmer Control - Proper Setting Dimmer Switch: Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Locations Steering Column Page 8285 License Lamps Locations Steering Column Multi-function Switch Page 4728 5. Attach the valve pressure bleeding tools J39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (figure 3) and to the combination valve (figure 4). Tighten tool J39177 only finger tight. 6. Open the pressure bleeder tank valve. 7. Bleed each wheel in the following sequence: - Right rear - Left rear - Right front - Left front NOTE: Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. NOTE: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 8. Open the bleeder valve at least 3/4 of a turn and allow the fluid to flow until no air is seen in the fluid. Tighten the bleeder valve. 9. Repeat step 7 and 8 at each wheel cylinder/caliper until all the air is purged. 10. Disconnect the bleeder tank hose from the bleeder adaptor and remove the bleeder adaptor. 11. Fill the master cylinder to the proper level and replace lid. 12. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs.in.). 13. Remove the valve pressure bleeding tools J39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 14. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. IMPORTANT: DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 15. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. IMPORTANT: DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 16. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs.in.). 17. Remove the bleeder adaptor, if using the pressure bleed procedure (figure 1), and fill the master cylinder to the proper level with brake fluid. 18. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. IMPORTANT: MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 19. Repeat the entire brake bleed procedure if necessary. Manual Bleed Procedure When a pressure bleeder is not available, use the (two person) manual bleed procedure. One person will push on the brake pedal while the other person will open and close the bleed valves. IMPORTANT: You can expect to use two quarts of brake fluid to thoroughly bleed the system. Page 1812 Engine Mount: Service and Repair Fig. 1 Front Engine Mount Installation FRONT ENGINE MOUNTING REPLACEMENT Remove or Disconnect -Raise the vehicle. Support with suitable safety stands. 1. Cab or body mounting bolts. Raise the body and block in position. 2. Engine mounting through-bolts on both sides. NOTICE: When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or the crankshaft pulley. Due to the small clearance between the oil pan and the oil pump screen, jacking against the oil pan may cause it to be bent against the pump screen, resulting in a damaged oil pickup unit. -Raise the engine and block in position. 3. Engine mounting to frame bolts. 4. Engine mounting. Install or Connect NOTICE: When fasteners are removed, always reinstall them at the same location from which they were removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be used. Fasteners that are not reused and those requiring thread locking compound will be called out. The correct torque value must be used when installing fasteners that require it. If the above condition are not followed, parts or system damage could result. 1. Engine mounting to the frame. 2. Engine mounting to frame bolts and nuts. -Tighten bolts to 57 Nm (42 ft.lbs) or nuts to 47Nm (35 ft.lbs) -Lower the engine. Page 4922 Clutch Start Switch: Service and Repair Fig. 3 Clutch Start Switch Installation 1. Remove lower I/P trim panel. 2. Remove clutch start switch electrical connector. 3. Remove clutch start switch from clutch pedal. 4. Reverse procedure to install, Fig. 3. Page 8219 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 760 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 4929 Symbol Identification Locations CMFI Assembly Parts Identification Page 4373 Wheel Bearing: Service and Repair REAR WHEEL BEARINGS AND/OR HUB Fig. 2 Axle Shaft Bearing Removal Fig. 3 Axle Shaft Bearing Installation Fig. 4 Axle Shaft Seal Installation 1. Remove axle shaft as described under AXLE SHAFT. 2. Remove axle seal by prying behind seal steel case with a pry bar. Use caution to avoid damaging axle housing. 3. Using a puller and slide hammer, remove axle bearing, Fig. 2. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer No. tool J-23765, or equivalent, until bearing is seated in housing, Fig. 3. 5. Lubricate seal lips with gear lubricant, then position seal on axle shaft seal installer tool No. J-23771 or equivalent, and install in axle housing, tapping into place until seal is flush with axle housing, Fig. 4. 6. Reinstall axle shaft. Page 5025 Figure 7 Figure 8 Figure 9 Figure 10 Page 8810 Wiper Switch: Service and Repair Fig. 8 Windshield Wiper Switch Removal (Front). Except Tilt Column Fig. 9 Windshield Wiper Switch Removal (Front). Tilt Column FRONT 1. Remove turn signal switch. Refer to Vehicle Lighting/Turn Signals/Turn Signal Switch/Service and Repair procedure. 2. Refer to Figs. 8 and 9 for wiper switch replacement. Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 4749 Removing Dust Boot 6. Carefully pry dust boot out of bore. 7. Using a small piece of wood or plastic, remove piston seal from bore. CAUTION: Do not use a metal tool of any kind to remove seal as it may damage bore. 8. Remove bleeder screw. ASSEMBLY NOTICE: Clean all parts in denatured alcohol or brake parts cleaner before assembly and dry the parts with dry compressed air. 1. Inspect caliper bore for scoring, nicks, corrosion or wear. Replace caliper housing if bore will not clean up with crocus cloth. 2. Lubricate caliper piston bore and new piston seal with clean brake fluid. Position seal in bore groove. Fig. 6 Installing boot to piston 3. Lubricate piston with clean brake fluid and assemble a new boot into the groove in the piston so the fold faces the open end of the piston, Fig. 6. 4. Using care not to unseat the seal, insert piston into bore and force the piston to the bottom of the bore. Page 7168 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Locations Horn Relay Installation Page 8130 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 5115 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Specifications Shifter Detent Spring: Specifications Detent Spring Cover Bolts ................................................................................................................... ..................................................................... 7 ft. lbs. Page 349 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 4562 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 858 Important When performing adjustments to vehicles requiring a 4-wheel alignment, set the rear wheel alignment angles first in order to obtain proper front wheel alignment angles. Perform the following steps in order to measure the front and rear alignment angles: 1. Install the alignment equipment according to the manufacturer's instructions. 2. Jounce the front and the rear bumpers 3 times prior to checking the wheel alignment. 3. Measure the alignment angles and record the readings. If necessary, adjust the wheel alignment to vehicle specification and record the before and after measurements. Refer to Wheel Alignment Specifications in SI. Important Technicians must refer to SI for the correct wheel alignment specifications. SI is the only source of GM wheel alignment specifications that is kept up-to-date throughout the year. Test drive vehicle to ensure proper repair. Page 5180 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 7636 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 333 Symbol Identification Page 337 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 519 Use applicable labor time guide for labor hours. Service and Repair Fuel Pressure Release: Service and Repair Fuel Supply System CMFI FUEL PRESSURE RELEASE PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure - Connect fuel pressure gauge to fuel pressure connection tap. Wrap a shop towel around fitting while connecting gauge to avoid spillage. - Install bleed hose into an approved container and open valve to bleed system pressure. Fuel connections are now safe for servicing. - Drain any fuel remaining in gauge into an approved container. Page 1669 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 5528 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 4508 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Page 2152 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Page 3971 A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Technical Service Bulletin # 467108 Date: 941201 A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Page 3983 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 5551 Front Wheel Alignment Specifications Page 698 Chart 6 Vehicle Speed Sensor Test Page 5223 Figure 7 Figure 8 Figure 9 Figure 10 Page 1424 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 2367 RH Front Side Of Engine. RH Side Of Engine Block Applicable to: 1991 4.3L/V6-262 Engine, Bravada Page 4666 2. Attach a dial indicator to a solid non-rotating portion of the hub assembly or suspension. - The point of the styles must contact the rotor face about 25 mm (1-inch) from the rotor edge. 3. Move the rotor one complete rotation and observe the dial indicator. 4. Rotate the bezel on the dial indicator such that "0" is at the low deflection point. 5. Again rotate the rotor at least one complete turn and observe the needle deflection. Total needle deflection will equal lateral runout. - The lateral runout should not exceed 0.08 mm (0.003-inch). 6. Readjust the wheel bearings. MINIMUM THICKNESS The thickness of a rotor is important for two reasons: 1. Rotors which are too thin are not able to properly absorb and release heat during heavy braking. This results in reduced braking capacity and brake fade. 2. Rotors worn below minimum thickness in combination with worn pads/linings can result in the caliper piston extending too far becoming cocked or jammed. Rotor thickness should be measured at the thinnest point on the rotor. Any rotor which is worn below its minimum thickness should be replaced. For accurate measurements, it is best to remove the caliper to allow for complete access to the inboard side of the rotor. Page 1423 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 8555 Symbol Identification Page 8545 Underhood Lamp: Electrical Diagrams Underhood Lamp Page 3392 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 3025 Throttle Position Sensor: Mechanical Specifications Throttle Position Sensor 18 in.lb Page 5261 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Aluminum Wheels - Cosmetic Damage During Balancing Wheels: All Technical Service Bulletins Aluminum Wheels - Cosmetic Damage During Balancing Number: 93-197-3E Section: 3E Date: MAY 1993 Corporate Bulletin No.: 393502 ASE No.: A4 Subject: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING Model and Year: 1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V 1990-93 LUMINA APV Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Clutch Pedal - Pop or Scrape Noise When Depressed Clutch Pedal Assembly: Customer Interest Clutch Pedal - Pop or Scrape Noise When Depressed File In Section: 7 - Transmission Bulletin No.: 46-73-03 Date: October, 1994 Subject: Clutch Pedal Return Spring Fractured (Remove Spring) Models: 1988-94 Chevrolet and GMC Truck C/K, S/T Models with Manual Transmission Condition Some owners may comment that they hear a pop or scrape noise, or feel a catch as they depress the clutch pedal. They may also comment that the clutch pedal return spring is fractured. This spring is located at the clutch pedal pivot. Cause Spring fatigue resulting in short service life. Correction Remove the clutch pedal return spring and DO NOT replace it. Refer to the appropriate Service Manual Section 7C - Clutch, Clutch Pedal Replacement for the correct procedure. Testing has shown that this spring is not needed for proper clutch pedal return or clutch pedal feel. This spring was eliminated in production as follows: ^ C/K all models, mid-1994 model year ^ S/T pickups, mid-1994 model year ^ S/T utilities, start of production 1995 model year Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time K0100 Spring, Clutch Use Published Labor Pedal Return Operation Time Locations Cargo Lamp Switch: Locations LH Side Of Instrument Panel. On LH Side Of Steering Column Applicable to: Except Bravada Service and Repair Speedometer Gear, A/T: Service and Repair 1. Disconnect speedometer cable. 2. Remove retainer bolt, retainer, speedometer driven gear, and O-ring seal. 3. Reverse procedure to install, using new O-ring and adjusting fluid level. Page 4821 Hydraulic Brake Booster: Description and Operation Hydro-Boost II Hydro-Boost II is an hydraulically operated power brake booster. The hydraulic brake booster consists of an open center spool valve and an hydraulic cylinder combined into a single housing. The power steering pump provides the hydraulic fluid pressure to operate both the power brake booster and the power steering gear. A dual master cylinder is bolted to the brake booster and is operated by a pushrod projecting from the booster cylinder bore. The Hydro-Boost II also has an accumulator system which stores sufficient fluid under pressure to provide one power assisted brake application when steering pump failure occurs. Page 420 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Two Wheel Drive - 2WD Wheel Bearing: Adjustments Two Wheel Drive - 2WD FRONT WHEEL BEARINGS ADJUSTMENT 4 X 2 MODELS 1. Raise and support front of vehicle. 2. Remove hub dust cover, then the cotter pin. 3. While rotating wheel assembly in forward direction, torque spindle nut to specification to fully seat the bearings. 4. Loosen nut to the ``just loose'' position, then tighten the spindle nut finger tight. 5. If either spindle hole does not line up with a spindle nut slot, back off spindle nut not more than 1/2 nut flat. 6. Install new cotter pin, then measure hub endplay. Endplay should be .001-.005 inches when properly adjusted. 7. Install hub dust cover and lower vehicle. 4 X 4 MODELS These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Page 4689 (unsafe) and the new shoes/linings will be subject to overheating and brake fade. How To Measure NOTE: For additional information on how to use a drum micrometer see Fundamentals and Basics. See: Fundamentals and Basics - A drum micrometer is used to measure the drum diameter. - The micrometer scale should be initially set to the original (new) thickness of the drum. - The base of the micrometer should be placed in the deepest groove in the drum and held steady while the measuring point is swiveled to find the maximum diameter. - The base and measuring point should be kept at the same depth in the drum. Drum Micrometer - The measurement should be repeated at 3 or more places around the circumference of the drum to determine if the drum is out of round. If the measurements differ by more than 0.004 inches the drum should be resurfaced. Diagram Information and Instructions Relay Box: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 4274 Fig. 10 Pinion depth gauge tool installation. Corvette Adjustment 1. Install pinion bearing races in housing using a suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, Fig. 8, noting the following: a. Assemble gauge plate onto preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. c. Rotate tool to ensure bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. of torque, which is required to rotate stud. To prevent damage to bearing, tighten nut in small increments, checking rotating torque after each adjustment. e. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. f. Mount arbor and plunger assembly in housing, ensuring side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving, Fig. 9. 4. Mount dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 3/4 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. Installation 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with a drift while assistant holds pinion in place. Old pinion nut and a large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. Page 7355 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 141 Figure 7 Figure 8 Figure 9 Figure 10 Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Page 634 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Page 3859 NOTE: In the overhaul repair kits for the HYDRA-MATIC 4L60 there are two (2) sets of 3rd and 4th clutch fiber plates. The two 3rd and 4th clutch fiber plates are calibration sensitive and interchanging the wrong plates may cause premature failure. The chart shows which models should use the plates labeled "2050" Figure 3. Page 8124 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 7363 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Campaign - 02-313 Stop Delivery Notice Update Fuel Level Sensor: Recalls Campaign - 02-313 Stop Delivery Notice Update ** ADMINISTRATIVE MESSAGE 01-277 CREATED ON 9/5/91 AT PAGE 1 OF 1 TO: ALL CHEVROLET DEALERS SUBJECT: STOP DELIVERY NOTICE 1992 S/T TRUCKS THIS IS WITH FURTHER REFERENCE TO THE 1992 S/T TRUCK STOP DELIVERY DCS ADMIN MESSAGE 01-258 DATED 8/22/91 SENT TO ALL CHEVROLET DEALERS. SELECT DEALERS WERE ADVISED IN DCS MESSAGE 02-313 DATED 9/5/91 OF PRODUCT CAMPAIGN 92C02 FUEL LEVER SENDER ARM/TANK INTERFERENCE. THIS DCS INCLUDED INVOLVED DEALER CODES AND INVOLVED VIN'S. ANY DEALER NOT RECEIVING DCS ADMIN MESSAGE 02-313 HAS NO INVOLVED VEHICLES ASSIGNED AND VIN'S WHICH FALL WITHIN THE ORIGINAL VIN RANGES LISTED BELOW ARE RELEASED FROM THE STOP DELIVERY. ASSEMBLY PLANT STARTING VIN ENDING VIN PONTIAC WEST N0100014 N0101228 MORAINE N2100052 N2101700 SHREVEPORT N8100014 N8101560 PLEASE COMMUNICATE THIS INFORMATION TO ALL DEALERSHIP MANAGEMENT IMMEDIATELY UPON RECEIPT. Page 1863 Oil Pressure Gage Is Inaccurate Page 7235 Symbol Identification Page 3884 Page 4704 Brake Shoe: Service and Repair Installation For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Exploded View 1. Lubricate parking brake lever fulcrum with suitable brake lube, then attach lever to brake shoe. Ensure lever operates smoothly. 2. Connect brake shoes with adjusting screw spring, then position adjusting screw. Ensure adjusting screw star wheel does not contact adjusting screw spring after installation, and also ensure right hand thread adjusting screw is installed on left side of vehicle and lefthand thread adjusting screw is installed on right side of vehicle. When brake shoe installation is completed, ensure star-wheel lines up with adjusting hole in backing plate. 3. Lightly lubricate backing plate shoe contact surfaces with suitable brake lube, then the area where parking brake cable contacts backing plate. 4. Install brake shoes on backing plate while engaging wheel cylinder links with shoe webbing. Connect parking brake cable to parking brake lever. The primary shoe (short lining) faces towards front of vehicle. NOTE: For additional information see Brake Spring Removal and Installation Notes. See: Fundamentals and Basics 5. Install actuating levers, actuating link and return spring. 6. Install hold-down springs with suitable tool. 7. Install primary and secondary shoe return springs using brake spring pliers or equivalent. Fig. 7 Measuring Brake Drum Inside Diameter Windshield/A Pillar - Pop Noise Diagnosis Dashboard / Instrument Panel: All Technical Service Bulletins Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Testing and Inspection Starter Drive/Bendix: Testing and Inspection There is no provision for adjusting pinion clearance on this type motor, but should be checked after motor reassembly on all models except the 28 MT, which is not serviceable. When the shift lever mechanism is correctly assembled, the pinion clearance should fall within the limits of .010 to .140 inch on 1987 models and .010-.160 inch on 1988-91 models. When the clearance is not within these limits, it may indicate excessive wear of the solenoid linkage or shift lever yoke buttons. Fig. 13 Connections For Checking Pinion Clearance Fig. 14 Checking Pinion Clearance Pinion clearance should be checked as follows: 1. Disconnect motor field coil connector from solenoid motor terminal, then insulate end carefully. 2. Connect one battery lead to solenoid switch terminal, then the other lead to the solenoid frame, Fig. 13. 3. Using a jumper lead connected to the solenoid motor terminal. Momentarily flash the lead to the solenoid frame. This will shift the pinion into the cranking position until the battery is disconnected. 4. Push the pinion back toward the commutator end as far as possible to take up any slack movement, then check the clearance with feeler gauge, Fig. 14. Page 1231 NOTICE: When performing the 4WAL brake system bleeding procedure, the ignition switch must be in the "OFF" position or false diagnostic trouble codes could be set to memory. If trouble codes are set, refer to section 5El "Clearing Diagnostic Trouble Codes" in the 1993 Service Manual. Pressure Bleed Procedure The pressure bleeding equipment must be of the diaphragm type. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. IMPORTANT: You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Begin by attaching the pressure bleeder adaptor J29567 to the master cylinder (figure 1). 2. Fill the pressure bleeder tank J29532 at least 2/3 full with Delco Supreme No. 11 Hydraulic Brake Fluid (GM P/ N 1052535) or an equivalent DOT 3 motor vehicle brake fluid. The bleeder tank must be bled each time brake fluid is added. 3. Charge the bleeder tank to 140-170 kPa (20-25 psi) and connect the hose from the bleeder tank to the bleeder adaptor. Page 160 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 4756 This results in the piston seals again being dragged across the layer of corrosion and deposits. Calipers which are not rebuilt or replaced have a higher probability of sticking or leaking. - Check to ensure the bleeder screw is not frozen prior to reinstalling caliper. Freeing a stuck bleeder screw is much easier with the caliper removed from the vehicle. Page 3655 Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Page 6262 Removing The Seal Cage - Press J 38468 against the seal spring and twist the tool until it engages the slots of the seal cage. Install or Connect Tools Required: J 29640 Shaft Protector J 38468 Shaft Seal Remover and Installer J 38479 Seal Seat Remover and Installer Clean Seal cavity thoroughly. a. Use R-12 refrigerant. Blow dry. b. Wipe with a lint tree cloth and clean refrigerant oil. Blow dry. 1. J 29640 over the compressor shaft. - Do not touch the new seal cage (21). 2. Slots of J 38468 to the new seal cage (21). Installing The Seal Cage 3. Seal assembly into place in the compressor seal cavity. - Twist J 38468 to disengage it from the cage. 4. Clean refrigerant oil to the shaft seal seat. 5. Shaft seal seat (23) with J 38479. 6. Snap ring with the flat side toward the compressor. Page 2833 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Page 7275 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Installation Notes Brake Rotor/Disc: Fundamentals and Basics Installation Notes WHEN INSTALLING A ROTOR/DISC, REMEMBER... Thoroughly clean the rotors with brake cleaner. - Any grease or brake fluid which comes in contact with the rotor should be thoroughly cleaned prior to installing the new pads/linings. - Grease and other contaminants become lodged in the microscopic pores of the rotor's surface. This prolongs the brake-in time of the new linings and contaminates the friction material. - Commercially produced aerosol brake cleaners should be used to clean the rotor. Unlike carburetor cleaner or other petroleum based solvents, brake cleaner does not leave a residue on the rotor's surface. Recheck the wheel bearings once the tires are installed. - With the vehicle raised and properly supported, grasp the tire at the top and bottom and attempt to rock them back and forth. There should be no detectable lateral (wobble) movement. Page 7559 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7797 low coolant temperature, the sender resistance is high. With high coolant temperature the sender resistance is low. If the coolant temperature exceeds 118°C (245°F), a box around the Coolant Temperature Gage ISO Symbol flashes to indicate an engine overheat condition. VOLTMETER DISPLAY The Voltmeter Display shows the battery voltage. The Voltmeter is connected to the PNK/BLK (39) wire and the BLK (150) wire. If the generator output is high, low or 0 volts, a box around the Voltmeter ISO Symbol flashes to indicate a problem with the charging system. This signal is sent to the cluster through the BRN (25) wire. TACHOMETER DISPLAY The Tachometer Display shows engine revolutions per minute (RPM). The Tachometer is connected to the WHT (121) wire. The Tachometer has a total range of 0-5500 RPM. The YELLOW warning region has a range of 4500-5000 RPM and the RED warning region has a range of 5000-5500 RPM. Page 7589 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 1832 Oil Filter: Technical Service Bulletins Engine - Cold Knock Number: 93-155A-6A Section: 6A Date: AUGUST 1993 Corporate Bulletin No.: 376105R ASE No.: A1, A8 Subject: COLD ENGINE KNOCK Model and Year: 1991-93 C/K, R/V, M/L, S/T, G TRUCKS WITH 4.3L, 5.7L AND 7.4L ENGINES THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 93-155-6A DATED MARCH 1993. THE CORRECTION SECTION HAS BEEN CHANGED COMPLETELY. COPIES OF 93-155-6A SHOULD BE DISCARDED. CONDITION: Some late model LB4 (VIN Z 4.3L V6), L05 (VIN K 5.7L V8), and L19 (VIN N 7.4L V8) truck engines have been reported to exhibit "cold knock" on start up. "Cold knock" usually occurs after the vehicle has been completely warmed, then parked for 8 or more hours in ambient temperatures of 35 degrees Fahrenheit or less. "Cold knock" can be separated into three distinct categories. A. Short Duration - Harsh deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. B. Valve Train - Light clatter, tick or click that may last up to 1 minute. C. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. CORRECTION - CATEGORY A: Short Duration Knock For 1992 LB4 4.3L VIN Z ONLY: Install PF52 oil filter. Install a revised PROM that reduces the engine spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROM will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROMs contain the previously released calibration update for torque converter clutch (TCC) lock-up (see Dealer Service Bulletin No. 92-75-7A) if the vehicle has an automatic transmission or neutral gear rattle if the vehicle has a manual transmission (see Dealer Service Bulletin No. 92-187A-7B). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Dealer Service Bulletin No. 92-285B-6E for more information on detonation. NOTE: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. SPO will be temporarily stocking four (4) PROMs for each light duty 1992 model year LB4 application. Base Detonation Fix Cold Knock Fix Combination Cold Knock and Detonation Fix The detonation fix (detonation fix only) PROMs will not be restocked by SPO when the current supply is exhausted. If a detonation fix PROM is required after the existing stock is exhausted, the combination cold knock and detonation PROM is to be used. Special Parts Assistance Center will have information available on each PROM. Select the PROM from the table. Old broadcast code (OLDB/C Code) information has been supplied to help determine if a detonation fix PROM has been installed previously. If the Old B/C Code can be found in the first table, a detonation fix has not been installed. If the broadcast code cannot be found in the tables, call the appropriate marketing division technical assistance group. PROMs are expected to be available from GMSPO August 30, 1993. Testing and Inspection Fuel Pump Control Unit: Testing and Inspection PROCEDURE: - Disconnect fuel module - With test light and ignition "ON", probe connector terminal "C" to ground. Circuit is OK if light is "ON". There is an open if the light is "OFF". - Probe connector terminals "C" to "D" with test light. Circuit is OK if light is "ON". There is an open in the ground circuit if light is "OFF". - Ignition "OFF", probe connector terminals "A" to "D" with test light. Ignition "ON", test light should illuminate for two seconds. There is an open in the circuit if the light is "OFF". - Replace fuel module if there is no twenty second fuel pump operation. Page 1440 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Page 8109 Brake Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 8101 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Page 2306 For vehicles repaired under warranty, use the table. Disclaimer Page 6390 Vehicle Limited Warranty, dealers are instructed to proceed as follows: Important: On vehicles equipped with A/C systems NOT produced by GM (i.e., rear A/C systems in van conversions), consult the manufacturer of that A/C system for retrofit guidelines. ^ Offer the customer the option of repairing and recharging the system with R12, or retrofitting after repair and recharging with R-134a at no additional charge. ^ Provide the owner with, and review the information contained in, the "Converting Your Auto Air Conditioning System to Use the New Refrigerant" brochure. (Brochure, Form GM-0011, can be ordered free of charge from GM Fulfillment HQ, Phone 1-800-269-5100). ^ Record the customer's choice on the repair order and, as with all properly completed repair orders, ask the customer to sign on the appropriate line acknowledging the repairs requested. ^ Under no circumstances should the retrofit to R-134a be performed unless the customer has had the option explained prior to repair. Once the vehicle has been retrofitted to R-134a, a significant expenditure would be incurred to go back to R-12, in the event the customer has changed his/her mind. THIS OFFER APPLIES ONLY TO VEHICLES REQUIRING A/C REFRIGERANT SYSTEM REPAIRS UNDER THE TERMS OF THE NEW VEHICLE LIMITED WARRANTY. It is not a special policy, and any existing deductibles still apply. This is simply an option being offered to the customer during the warranty period at this time. GM reserves the right to terminate this offer at any time. If the R-12 refrigerant system does not require discharging for a warranty repair, but the customer requests a retrofit to R-134a, the retrofit WOULD BE PERFORMED AT THE CUSTOMER'S EXPENSE, EVEN DURING THE WARRANTY PERIOD. 2. Customer Paid Retrofitting Costs If the customer requests a retrofit to R-134a, for a specific vehicle whose retrofit parts and procedures have been released in this bulletin, the customer would be expected to pay the costs to retrofit under the following conditions: ^ The vehicle is no longer covered by the terms of the New Vehicle Limited Warranty. ^ The vehicle is covered by warranty, but the repair covered under the warranty does not require evacuating and recharging the refrigerant system. 3. Labor Time Information For Vehicles Repaired Under Warranty: Use existing labor operations for correcting the original condition. The quantity of R-134a used should be charged to the normal labor operation (not D4500), just as if it were R-12. Use D4500, 0.3 HR., to charge for parts and labor, for all of the following items: ^ Additional time for recovery of R-12 to meet SAE standards; ^ Install high and low side service port converter fittings; ^ Add PAG or V5 retrofit oil; ^ Complete label information and install. Add 0.2 hours to D4500 for installation of the HPCOS. Use T5321, 0.3 HR., for the Pontiac Bonneville hood seal installation. ANY PARTS OR LABOR TIME OTHER THAN THOSE LISTED ABOVE SHOULD BE CHARGED TO THE REGULAR LABOR OPERATION CORRESPONDING TO THE ORIGINAL CONDITION THAT 1S BEING REPAIRED. Page 5447 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 5466 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7166 Symbol Identification Description and Operation Overvoltage Protection Relay: Description and Operation PURPOSE Inform the control module that there is a basic generator over voltage problem. OPERATION PCM/ECM If voltage is greater than 19.5 volts for 2 seconds at PCM terminal "E16" (ECM is "C16"), the control module sets Diagnostic Trouble Code 53, the automatic transmission pressure control solenoid is turned "OFF", the automatic transmission shifts immediately to third gear, and TCC operation is inhibited. (the setting of additional DTC's may result.) VCM If voltage is greater than 17.1 volts at VCM terminal "GR2" sets Diagnostic Fault Code P1632. For 2 seconds after the fault is detected, the VCM will disengage its outputs. This may result in additional DTC's being set. Page 4239 a. Apply marking compound on ring gear teeth. b. Rotate drive pinion one revolution and check gear tooth contact pattern as shown on Fig. 4. Add or remove shims as required. c. After backlash and tooth pattern operation has been completed, remove shim packs using caution not to mix them. d. Select new shims for each side .004 inch thicker than those removed, then install each shim on its proper side. This additional thickness will ensure proper bearing preload. e. Check total rotational torque. Total torque with differential case preloaded and pinion installed should be 16-29 inch lbs. if new bearings are installed or 10-16 inch lbs. if original bearings are installed. f. If total rotational torque is not as specified, repeat steps 4 through 10. 11. If drive pinion was removed, remove differential case and shims, then proceed to DRIVE PINION & BEARING SHIM ADJUSTMENT procedure. Page 415 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 142 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 4683 Backing Plate: Testing and Inspection Inspect backing plate shoe contact surface for grooves that may restrict shoe movement and cannot be removed by lightly sanding with emery cloth or other suitable abrasive. If backing plate exhibits above condition, it should be replaced. Also inspect for signs of cracks, warpage and excessive rust, indicating need for replacement. Page 8270 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 135 Symbol Identification Diagram Information and Instructions Relay Box: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 3324 Fuel Return Line: Description and Operation The fuel feed and return pipes and hoses extend from the fuel pump and sender to the TBI unit. They are secured with clamps and are routed along the frame side member. The vapor pipe and hoses extend from fuel pump and sender unit to the Evaporative Emission (EVAP) control vapor canister. Page 4074 Torque Converter Clutch (TCC) Circuit Circuit Description: The purpose of the automatic transmission Torque Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise condition. This allows for the convenience of the automatic transmission and the fuel economy of a manual transmission. Fused battery ignition is supplied to the TCC solenoid through the TCC brake switch. The ECM will engage TCC by grounding CKT 422 to energize the solenoid. TCC will engage when: - Vehicle speed above 30 mph (48 km/h) - Engine at normal operating temperature (above 65°C 149°F) - Throttle position sensor output not changing, indicating a steady road speed. - Brake switch closed - Third or Forth gears Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. A test light "ON" indicates battery voltage and continuity through the TCC solenoid is OK. 2. Checks for vehicle speed sensor signal to ECM using a "Scan" tool. 3. Checks for forth gear signal to ECM. This signal will not prevent TCC engagement, but could cause a change in the engage and disengage speed points. Diagnostic Aids: Solenoid coil resistance must measure more than 20 ohms. Less resistance will cause early failure of the ECM "driver". See: Powertrain Management/Computers and Control Systems/Engine Control Module/Testing and Inspection With an ohmmeter, check the solenoid coil resistance of all ECM controlled solenoids and relays, before installing a replacement ECM. Replace any solenoid, or relay that measures less than 20 ohms resistance. To prevent TCC overheat condition, TCC temperature closes at 279°F +/- 7° and reopens at 259°F +/- 9°. Diagram Information and Instructions Brake Vacuum Release Valve: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Page 5189 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 4553 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 332 Symbol Identification Page 7764 Capacity Specifications Engine Oil: Capacity Specifications Engine Oil without Filter ....................................................................................................................... ............................................... 4.0 quarts (3.8 liters) NOTE: All capacities are approximate. When adding, be sure to fill to the approximate level. Recheck fluid level after filling Page 8385 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Page 8725 used when the customer demands quicker repair of the vehicle than the above described one-part product can provide. This two-part, chemical cure product requires ONE (1) TO ONE-AND-ONE-HALF (1-1/2) HOURS FOR CURING BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This two-part product also requires primers on the glass and pinchweld surfaces. The primers and applicator daubers are not included with this two-part product and therefore, must be purchased separately. In addition, this two-part product requires a special applicator (gun) for proper mixing and dispensing of the adhesive. Important: The U216 product is NOT available from GMSPO and must be obtained locally. * We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. When using either of the above described products, make sure to follow the manufacturer's directions for application and drying times. For information regarding the removal and installation of stationary glass, consult the appropriate Service Manual. Parts information P/N Description 12346392 Urethane Adhesive Caulking Kit Parts are expected to be available from GMSPO, 10/12/98. Important: The previously recommended adhesive kit (P/N 12346284) will no longer be available from GMSPO once inventory is exhausted. Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Page 4279 Pinion Bearing: Adjustments Corporate and Eaton 7 1/2 - 8 7/8 Inch Ring Gear Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly J-23597-01 for models with 7-1/2 inch ring gear, J-21777-01 Page 1388 degradation. Important Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Disclaimer Page 7724 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 8260 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 3379 Use applicable labor time guide for labor hours. Locations Service Port HVAC: Locations The high pressure fitting is located either in the high pressure vapor line or muffler, while the low pressure fitting is located on the accumulator. Page 485 Control Cable REMOVE OR DISCONNECT 1. Screws (64). 2. Control assembly (63). NOTICE: Pull control assembly (63) out of the instrument panel far enough to reach the control cable assembly ends arid the blower switch electrical connector. 3. Electrical connection (82). 4. Control cables (60 and 65). 5. Blower switch if necessary. NOTICE: Remove the blower switch knob and spring clip, and remove the blower switch. Inspect - Electrical terminals for corrosion. Remove the corrosion or replace the component as necessary. - Temperature and mode levers for freedom of movement. Lubricate, repair or replace as necessary. - Control cable assemblies for kinks, binding and other damage. Repair or replace as necessary. INSTALL OR CONNECT 1. Heater blower switch if removed. - Hold the blower switch in position and install the spring clip. Page 5063 Symbol Identification Page 3166 Idle Speed: Adjustments NOTE: Before performing this check: - Verify no codes displayed. - Idle air control system has been checked. - Ignition timing is correct. CONTROLLED IDLE SPEED CHECK - Set parking brake and block drive wheels. - Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. - START engine and bring it to normal operating temperature. - Check for correct state of PARK/NEUTRAL switch on SCAN tool. - Check specifications chart for controlled idle speed and IAC valve pintle position (counts). - If within specifications, the idle speed is being correctly controlled by the control module. - If not within specifications, refer to DIAGNOSIS BY SYMPTOM. See: Testing and Inspection MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable on this engine. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Auto D 550 5-40 CL [1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). Page 3972 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Page 4595 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 5481 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Service and Repair Front Crankshaft Seal: Service and Repair Fig. 16 Installing Front Oil Seal 1. Disconnect battery ground cable. 2. Remove fan belt, fan and pulley. 3. Remove fan shroud, then the accessory drive pulley. 4. Remove torsional damper. 5. Remove front crankshaft seal by prying out with large screwdriver. Ensure not to distort front cover. 6. Remove crankshaft key, if necessary. 7. Coat seal lips with engine oil and install using crankshaft seal installer tool No. J-35468 or equivalent Fig. 16. 8. Reverse steps 1 through 6 to complete installation. Locations Oil Pressure Switch (For Fuel Pump): Locations Rear Of Engine Oil Pressure Switch 4.3L Utility Page 8521 Underhood Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 1151 - J 41265 Thread cleaning wire brush - J 41266 Low side port thread restorer - J 41267 High side port thread restorer - J 39037 High side octagon socket - J 41256 Low side octagon socket New low profile, quick connect couplers, J 39500-20A (High side), and J 39500-24A (Low side), have been released as essential tools, to attach to the ACR4 (see Figure 3). These are much smaller couplers than the existing ones, and will allow attachment to the port fittings in much tighter quarters. Wheels/Tires - Use of Nitrogen Gas in Tires Tires: All Technical Service Bulletins Wheels/Tires - Use of Nitrogen Gas in Tires INFORMATION Bulletin No.: 05-03-10-020C Date: April 27, 2010 Subject: Use of Nitrogen Gas in Tires Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-03-10-020B (Section 03 - Suspension). GM's Position on the Use of Nitrogen Gas in Tires General Motors does not oppose the use of purified nitrogen as an inflation gas for tires. We expect the theoretical benefits to be reduced in practical use due to the lack of an existing infrastructure to continuously facilitate inflating tires with nearly pure nitrogen. Even occasional inflation with compressed atmospheric air will negate many of the theoretical benefits. Given those theoretical benefits, practical limitations, and the robust design of GM original equipment TPC tires, the realized benefits to our customer of inflating their tires with purified nitrogen are expected to be minimal. The Promise of Nitrogen: Under Controlled Conditions Recently, nitrogen gas (for use in inflating tires) has become available to the general consumer through some retailers. The use of nitrogen gas to inflate tires is a technology used in automobile racing. The following benefits under controlled conditions are attributed to nitrogen gas and its unique properties: - A reduction in the expected loss of Tire Pressure over time. - A reduction in the variance of Tire Pressures with temperature changes due to reduction of water vapor concentration. - A reduction of long term rubber degradation due to a decrease in oxygen concentrations. Important These are obtainable performance improvements when relatively pure nitrogen gas is used to inflate tires under controlled conditions. The Promise of Nitrogen: Real World Use Nitrogen inflation can provide some benefit by reducing gas migration (pressure loss) at the molecular level through the tire structure. NHTSA (National Highway Traffic Safety Administration) has stated that the inflation pressure loss of tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "seeping" through the tire casing. The actual obtainable benefits of nitrogen vary, based on the physical construction and the materials used in the manufacturing of the tire being inflated. Another potential benefit of nitrogen is the reduced oxidation of tire components. Research has demonstrated that oxygen consumed in the oxidation process of the tire primarily comes from the inflation media. Therefore, it is reasonable to assume that oxidation of tire components can be reduced if the tire is inflated with pure nitrogen. However, only very small amounts of oxygen are required to begin the normal oxidation process. Even slight contamination of the tire inflation gas with compressed atmospheric air during normal inflation pressure maintenance, may negate the benefits of using nitrogen. GM Tire Quality, Technology and Focus of Importance Since 1972, General Motors has designed tires under the TPC (Tire Performance Criteria) specification system, which includes specific requirements that ensure robust tire performance under normal usage. General Motors works with tire suppliers to design and manufacture original equipment tires for GM vehicles. The GM TPC addresses required performance with respect to both inflation pressure retention, and endurance properties for original equipment tires. The inflation pressure retention requirements address availability of oxygen and oxidation concerns, while endurance requirements ensure the mechanical structure of the tire has sufficient strength. This combination has provided our customers with tires that maintain their structural integrity throughout their useful treadlife under normal operating conditions. Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Maintaining the correct inflation pressure allows the tire to perform as intended by the vehicle manufacturer in many areas, including comfort, fuel economy, stopping distance, cornering, traction, treadwear, and noise. Since the load carrying capability of a tire is related to inflation pressure, proper inflation pressure maintenance is necessary for the tire to support the load imposed by the vehicle without excessive structural Page 4061 than a standard fan. These benefits are possible through the addition of a thermostatic clutch to the fan drive. When the engine is cool the clutch allows the fan to "slip" or turn at a speed slower than the engine. By turning at a slower speed the fan uses less horsepower, which saves fuel, and is quieter. When the engine temperature reaches a preset temperature, the fan "engages" and turns at the same speed as the engine. "Engagement" of the fan provides increased airflow through the radiator to cool the engine. As the airflow increases, fan operation becomes clearly audible. This increase in noise can easily be mistaken for an increase in engine RPM and may be incorrectly blamed on the automatic transmission. When operating an unloaded vehicle in cooler ambient temperatures, the thermostatic clutch usually won't engage. However, if the vehicle is pulling a trailer, heavily loaded or operated at high ambient temperatures the thermostatic clutch may cycle on and off as the engine temperature rises and falls. The sound of fan operation under the conditions described above is a sign that the cooling system on your vehicle is working correctly. Replacement or modification of cooling system or transmission parts will not change or reduce the noise level. Attempts to reduce this noise will only give you, the customer, a false sense of vehicle unreliability and the inconvenience of having your vehicle out of service. Page 4873 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 3749 [341] Hesitation or sag during the first two minutes of cold operation while vehicle is under moderate to heavy throttle driveaway, or TCC chuggle. [342] Cold start-stall, hesitation, or sag when the engine coolant is between 36°F - 111°F (2°C 44°C); or Inadequate A/C performance when driving at steady speed and throttle position, between 24 - 64 MPH, when the cruise control is not being used. [343] Engine does not stay running on initial cold start and chuggle at 35-45 MPH with TCC engaged. New MEM-CAL may affect fuel economy. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH SCANNER ID 5644 BUT A BCC OF A [344] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [345] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [346] Cold engine extended crank. USE 16181883 (SCAN I.D. = 0894) FOR COLD START STALL. USE 16181875 (SCAN I.D. = 0874) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [347] Cold engine extended crank. USE 16181887 (SCAN I.D. = 0904) FOR COLD START STALL. USE 16181879 (SCAN I.D. = 0884) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [348] Service Engine Soon light (SES) with a code 43 or tip-in sag, tip-in hesitation, surge at WOT, or spark detonation when cold. [349] Engine stall. MANUAL TRANSMISSION CARS SHOULD ALSO BE UPDATED WITH THE CLUTCH ANTICIPATE SWITCH PER DEALER SERVICE BULLETIN NO. 91-472-7C. [350] Engine does not stay running on initial cold start and chuggle at 35-45 MPH with TCC engaged. New MEM-CAL may affect fuel economy. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH SCANNER ID 5644 BUT A BCC OF A. Page 5748 Suspension Spring ( Coil / Leaf ): Service and Repair Rear Suspension Leaf Spring Fig. 5 Rear Suspension (Left Side) REMOVAL 1. Raise vehicle and place jack stands under frame side rails to relieve spring load. Support axle assembly. 2. On 1988-93 models, remove shock absorber. 3. Loosen, but do not remove, spring to shackle attaching nut, Fig. 5. 4. Remove U-bolt attaching nuts, then the U-bolts. 5. Remove shackle to frame attaching nut and bolt. After removal of shackle to frame attaching nut and bolt, spring is free to rotate on front hanger bolt. Use restraining device to prevent rotation. 6. Remove front spring hanger nut and bolt, then the spring. BUSHING 1. Remove spring assembly. 2. Place spring in press and press out bushing. INSTALLATION 1. Clean axle spring pad and apply a rubber lubricant to the bushing and the spring eye. 2. Using a press install bushing to spring assembly. 3. Install spring assembly to vehicle. Capacity Specifications Fluid - M/T: Capacity Specifications 5 Speed 4.4 pt (US) Page 5857 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Page 8145 Brake Light Switch: Service and Repair Fig. 2 Stop Light Switch Installation 1. Disconnect battery ground cable. 2. Disconnect wiring connector from brake light switch located on brake pedal bracket. 3. Pull switch from mounting bracket. 4. Depress brake pedal, then push new switch into clip until shoulder bottoms out, Fig. 2. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed .53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Page 5470 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 6909 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 1653 needle bearing of the balance shaft. 4. To eliminate the possibility of the rear needle bearing rattling, a production running change was made in early May 1992, to a different type bearing. The needle bearing was changed to a journal type sleeve bearing (much like a camshaft bearing). This type bearing requires pressure fed oil, therefore, an engine block casting change was made to allow an oil passage to be drilled from the vertical oil gallery coming from the oil filter to the rear balance shaft journal. 5. If the detonation type rattle noise is unacceptable to the customer, the engine must be replaced using an SPO Goodwrench engine assembly part number 12520408. Important: Dealers are to retain all parts replaced for inspection in accordance with GM Service Policy and Procedures section 1.7.4 - Disposition of Defective material. Important: Replaced engine blocks are NOT to be provided to engine rebuilders. They should be returned as per instructions shipped with the replacement engine. 6. MEM-CAL information: When replacing a 1992 needle bearing engine (only produced prior to the May 1992 VIN break-points) with a sleeve bearing engine, the MEM-CAL must be updated to the later 1992 version. See part number information below. These new MEM-CALs are required to change the ESC calibration for the sleeve bearing engine. Without the correct calibration MEM-CAL, the engine will detonate. 7. ESO (Electronic Spark Control) information: The sleeve bearing engine "sounds" different to the ESO system. To make the sleeve bearing engine operate properly the 1992 M and L van vehicles, the knock sensors and locations have been changed. The 1992 M/L motors require only one 3900 ohm knock sensor mounted in the transmission flange close to the distributor. Connect the knock sensor harness to the knock sensor in the transmission flange. The second knock sensor connector harness at the middle of the right cylinder head will not be used on the 1992 model year M and L vans with the sleeve bearing engines. To ensure the harness does not lie on the exhaust manifold and short out, tie the connector back onto the harness using a plastic tie strap. The S and T trucks will continue using both 8200 ohm knock sensors with the sleeve bearing engine. No modification to the existing harness is necessary. Sleeve Bearing Balance Shaft Knock Sensor Information VIN Breakpoints for Sleeve Bearing Engines Beginning with: Oil Pressure Gauge - Incorrect or Erratic Readings Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Incorrect or Erratic Readings Number: 93-57-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268304 ASE No.: A1, A8 Subject: INCORRECT OR ERRATIC OIL PRESSURE READINGS Model and Year: 1990-93 ALL LIGHT DUTY TRUCKS Owners of some 1990 through 1993 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. Service Procedure: Check for normal causes of high oil pressure gauge readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure below. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. connect the negative battery cable. Parts Information: Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Page 5548 What corrected the customer concern and was the repair verified? Please Explain: ............. Disclaimer Page 7555 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Speedometer - Registers When Vehicle is Stationary Vehicle Speed Sensor: Customer Interest Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. Page 6176 - Insert J 37828 into the snap ring groove. Removing The Rotor Pulley - Insert J 37827 over the exposed shaft. - Align the thumb head bolts of J 8433 to the puller fingers and tighten. Removing The Rotor Pulley (2 Of 2) - Turn the puller center Dolt to the right with a socket wrench until the rotor pulley is free. 7. Field coil (10). - Loosen the coil lead wire from the clip on top of the compressor front housing. Removing The Coil Snap Ring - Remove the snap ring (7). - Remove the coil. Install or Connect Page 2309 1. Engine coolant. ^ Drain enough coolant into a clean container to lower the coolant level below the level of the lowest heater hose fitting. 2. Heater hoses. 3. Rear case screws. 4. Rear case. 5. Screws. 6 Brackets. 7. Heater core from front case. 8. Seals Install or Connect 1. Seals 2. Heater core from front case. 3. Brackets. 4. Screws. 5. Rear case. 6. Rear case screws. 7. Heater hoses. 8. Engine coolant. ^ Use the coolant drained earlier only if it is uncontaminated. Discard contaminated coolant and add fresh 50/50 coolant and water mixture. Page 8222 Hazard Warning Flasher: Electrical Diagrams Hazard Flashers Without Digital Cluster Clutch Pedal Switch Clutch Switch: Locations Clutch Pedal Switch Brake Pedal Switches. On Clutch Pedal Support Service and Repair Blower Motor Switch: Service and Repair Wiring Harness Installation Control Assembly Page 1285 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 6661 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 6429 Page 7217 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 7287 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 8112 Figure 7 Figure 8 Figure 9 Figure 10 Page 768 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 5227 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 5231 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 6340 1. Engine coolant. ^ Drain enough coolant into a clean container to lower the coolant level below the level of the lowest heater hose fitting. 2. Heater hoses. 3. Rear case screws. 4. Rear case. 5. Screws. 6 Brackets. 7. Heater core from front case. 8. Seals Install or Connect 1. Seals 2. Heater core from front case. 3. Brackets. 4. Screws. 5. Rear case. 6. Rear case screws. 7. Heater hoses. 8. Engine coolant. ^ Use the coolant drained earlier only if it is uncontaminated. Discard contaminated coolant and add fresh 50/50 coolant and water mixture. Page 1671 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 6673 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Control Module Replacement Engine Control Module: Service and Repair Control Module Replacement Figure 1 CAUTION [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, Do NOT touch the connector pins or soldered components on the circuit boards. NOTE When replacing a production control module with a service controller, transfer the broadcast code and production control module part number to the controller label. DO NOT record information on the access cover. REMOVE/DISCONNECT - Negative battery terminal. - Passenger side kick panel. - Hush panel if equipped. - Mounting screw. - Control module from mounting bracket. - VSS buffer connector and rotate control module to ease removal. - Control module harness connectors. - Mounting brackets and modules if equipped. - Remove new control module from its packaging and check the service number to make sure it is the same as the defective control module. - PROM removal. Refer to PROM (MEM-CAL) replacement. NOTE Replacement control module is supplied without a PROM, so care should be used when removing it from the defective control module, because it will be reused in the new control module. INSTALL/CONNECT - Mounting brackets and modules if equipped. - Control module harness connectors. - VSS buffer connector and rotate control module to ease installation. - Control module into mounting bracket. - Mounting screw. - Hush panel if equipped. - Passenger side kick panel. Page 1993 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Coolant Temperature Switch Engine Wiring, LH Side Page 8801 Wiper Motor: Description and Operation Rectangular Motor Fig. 1 Rectangular windshield wiper motor. Shown w/washer pump installed Fig. 2 Rectangular windshield wiper motor electrical connections The rectangular motor, Fig. 1, consists of an armature, brush plate assembly, field coils and a housing which is attached to a gear housing. The motor electrical connections, park switch, and on some models a washer pump are also mounted on the gearbox. A gear on the commutator end of the armature drives an intermediate gear and pinion assembly, which in turn drives the output shaft. A crank arm on the output shaft operates wipers through a pivot link (transmission) assembly. When ignition is on, battery voltage is supplied to motor terminal 2, Fig. 2. Current flows through the series field to a splice where it is divided, and part passes through the armature and part through the shunt field. The armature and shunt field circuits are completed to ground through the wiper switch , with motor speeds determined by resistance in the shunt field ground path. Placing wiper switch in low position, grounds motor terminals 1 and 3, Fig. 2, at the wiper switch. Shunt field current flows directly to ground through terminal 3, armature current flows to ground through terminal 1 and the motor runs at low speed. Placing wiper switch in high position grounds terminal 1, but terminal 3 remains open. Armature current flows directly to ground through terminal 1, shunt field current flows to ground through a resistor connected between terminals 1 and 3, and the motor runs at high speed due to the weakened shunt field. When wiper switch is turned off, and wipers are not in park position, terminal 1 is grounded through the closed motor park switch contacts. Terminals 1 and 3 are connected through the wiper switch, and the motor runs at low speed. When wipers reach their lowest point of travel, a cam on the motor output shaft opens the park switch, and the motor stops. On models with pulse wipers, a pulse control module provides a delay wipe mode through the low speed circuit. When wiper control is in delay position, battery voltage is supplied to a capacitor in the module through a variable resistor. When the capacitor is fully charged, it activates a switching circuit which provides a ground to begin wiper operation. As the motor operates, park switch contacts close, the capacitor discharges, and the motor ground is maintained through the park switch. When wipers complete their cycle, the park switch opens and the capacitor begins to recharge. Delay between wipe cycles is determined by a variable resistor, which controls charging current to the capacitor. Higher resistance produces a longer delay. Page 4939 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 5458 Symbol Identification Page 2386 Thermostat: Service and Repair 1. Disconnect battery ground cable. 2. Drain coolant from radiator, then remove water outlet retaining bolts. 3. Remove outlet and gasket, then the thermostat from the outlet. 4. Reverse procedure to install. Page 2185 RH Front Side Of Engine. RH Side Of Engine Block Applicable to: 1991-92 4.3L/V6-262 Engine, Except Bravada Page 6273 Condenser HVAC: Service and Repair Fitting And Hose Installation Condenser Mounting REMOVE OR DISCONNECT 1. Discharge and recover refrigerant from the system. 2. Upper fan shroud. 3. Radiator. 4. Refrigerant hose (3) from condenser (4). 5. Evaporator tube (5) from condenser (4). 6. Bolts (18) and retainers (17). 7. Upper insulators (16). 8. Condenser (4). INSTALL OR CONNECT Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Page 5943 Page 6420 C. Parts Information D. Warranty Information 1. Vehicle Still in Warranty 2. Customer Paid' Retrofitting Costs 3. Labor Time Information Notes on Retrofit Important: Before proceeding with any retrofit, make sure you have all component Parts required on hand to perform a proper and complete repair with Minimal downtime. R-12 Removal Prior to Retrofit To prepare a system for retrofitting, the R-12 must be recovered and the system must be completely evacuated. Evacuation is necessary to insure that small amounts of R-12 and air remaining in the system are removed. This will prevent cross contamination of the two refrigerants, which could lead to reduced A/C system reliability and performance. It is very important that the specified times for waiting after recovery and evacuation not be reduced. This time is required to sufficiently remove residual R-12 from the oil in the system. A considerable amount of testing has determined that the following procedure is required to achieve satisfactory results and conform to SAE J 1661: 1. Inspect Condition of Vehicle Install the gauge set on the high and low side ports. Use normal diagnostic procedures to find the cause of the vehicle's reported condition. One of three conditions will exist with the refrigerant system: a. System pressure correct, no leaks - proceed to Step 2 (Recovery). This would normally apply when: 1. The system must be recovered/recharged for a repair to a system other than the A/C system, or 2. Where the A/C system condition did not involve leaks, but requires recovery/recharge to replace a component. b. Compressor not operating, but some charge. Leak test to find the leak, complete Step 2 (Recovery), then correct the leak before proceeding with Step 3 (Conversion port installation). c. No charge in system - proceed with the Conversion port installation in Step 3. Use the ACR4 to evacuate for 5 minutes. If the leak can be heard, repair the leak. If the leak cannot be heard, charge with 1/2 pound of R-134a. Leak test with the J 39400 Leak Detector, recover the R-134a, repair any additional leaks found, and proceed with the evacuation in Step 5. 2. Recover the R-12 from the System Notice: THIS PROCEDURE IS DIFFERENT THAN THE NORMAL (NON-RETROFIT) RECOVERY PROCEDURE. R-12 will be recovered through the HIGH SIDE SERVICE PORT ONLY, WITH THE ENGINE RUNNING. Recovery through the low side will not effectively remove the R-12 from the accumulator, resulting in possible damage to the retrofitted system. Important: Vehicle must be above 50° F (10° C) to allow for complete recovery of the R-12. If it is not, either allow it to warm up in the shop overnight, or increase the evacuation time in Step 5.a to 30 minutes. a. Connect the recovery hose from the R-12 recovery cart (ACR3) to the middle port of the A/C gauge set. Open the oil drain valve on the ACR3 cart long enough to drain the oil. Failure to do so could cause excessive amounts of oil to build up in the separator, resulting in damage to the recovery cart compressor. b. Start the engine. Leave the hood up, and the windows open. On vehicles with manual A/C controls, set the A/C controls to normal A/C mode, high blower, and temperature control to full cold. On cars with automatic A/C controls, set the temperature to 75° F, "AUTO" mode, and manually select high blower. Locations Steering Column Page 5374 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 6655 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 5232 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Page 7444 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Brake Line Brake Hose/Line: Specifications Brake Line Fitting (Steel) 16 ft.lb Page 7462 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Speed Sensor Buffer & Digital Ratio Controller (D.R.A.C.) Vehicle Speed Sensor Signal Buffer: Description and Operation Speed Sensor Buffer & Digital Ratio Controller (D.R.A.C.) VSS Buffer Amplifier On vehicles with conventional instrumentation, a vehicle speed sensor (VSS) buffer amplifier is used to supply the vehicle speed signal to the cruise control module. On this type system, a speedometer frame mounted optic head is used to pick up light reflected by a speedometer cable mounted blade. The reflected light is produced by a light emitting diode (L.E.D.). As the speedometer cable mounted blade enters the L.E.D. light beam, the light is reflected into the optic head. From there, the light enters a photocell in the optic head and produces a low power signal. This signal is sent to a buffer for amplification and conditioning, then to the controller. Digital Ratio Adapter Controller On vehicles with electronic instrumentation, a digital ratio adapter controller (DRAC) is used to supply the vehicle speed signal to the cruise control module. On this type system, the DRAC receives vehicle speed signals from a transmission or transfer case mounted vehicle speed sensor. The DRAC is calibrated according to axle ratio and tire combination, and provides 40 electronic pulses per revolution of the transmission or transfer case output shaft. Page 7565 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: All Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Page 2395 Catalytic Converter: Description and Operation CAUTION Prolonged operation with a misfiring or flooded engine may cause the converter to overheat. This could cause damage either to the catalyst itself or the operating vehicle and possible personal injury. NOTE When jacking or lifting vehicle from frame side rails, be certain lift pads DO NOT contact catalytic converter or damage to converter may result. Catalytic Converters Page 6928 After installing floor mats, make certain they cannot move and do not interfere with the accelerator or brake pedals. Disclaimer Page 8580 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 7666 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 6337 For vehicles repaired under warranty, use the table. Disclaimer Page 5020 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 7904 Malfunction Indicator Lamp: Description and Operation PURPOSE The Malfunction Indicator Lamp (MIL), "Service Engine Soon" light has the following purposes: Inform the driver that a problem has occurred, and that the vehicle should be taken for service as soon as reasonably possible. - Displays Diagnostic Trouble Codes (DTC) stored by the ECM helping the technician diagnose system faults. - Indicates "Open Loop" or "Closed Loop" operation. OPERATION The MIL will come "ON" with the key "ON" and the engine not running. When the engine is started, the light will turn "OFF.". This is a bulb and system check. If the light remains "ON," the self-diagnostic system has detected a problem. If the problem goes away, the light will go out in most cases after 10 seconds, but a DTC will remain stored in the ECM. Page 2954 Engine Wiring, LH Side Page 5298 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Page 3887 Page 6207 Compressor Clutch Coil: Service and Repair With V5 Compressor Remove or Disconnect 1. Perform Steps 1 through 4 of "Clutch Rotor and/or Bearings" removal procedure. Mark clutch coil terminal location on compressor front head. Clutch Coil Assembly Removal 2. Install J 33023-A puller pilot on front head of compressor. Also install J 8433-1 puller crossbar with J 33025 puller legs as shown in the illustration. 3. Tighten J 8433-3 forcing screw against the puller pilot to remove the clutch coil. Install or Connect 1. lace the clutch coil assembly on the front head with the terminals positioned at the "marked" location. 2. Place the J 33024 clutch coil installer over the internal opening of the clutch coil housing and align installer with the compressor front head. Page 7675 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 4605 Antilock Brake Module: Electrical Diagrams Fig. 7 Four Wheel Anti-lock Brake Wiring Circuit. Bravada, Astro/Safari & 2WD S/T Page 7371 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 4678 A full rotation will move the thimble exactly one minor division on the sleeve. To read the micrometer you must add the measurement which is visible on the sleeve to the measurement which is showing on the thimble In the example the sleeve measurement is 0.250 inches and the thimble measurement is 0.017 inches. The total measurement is then equal to the two measurements combined, 0.267 inches. NOTES The accuracy and calibration of a micrometer can be altered easily by applying too much pressure to the spindle. Use the thimble to quickly rotate the spindle in until it is near the rotor. - Use the ratchet to rotate the spindle into contact with the rotor. - The ratchet has a built in slip which prevents excessive stress or pressure from developing. Calibrate the micrometer regularly. Most micrometers come with a precision dowel which allows for easy and accurate adjustments. Page 2829 Rear Of Engine Page 6918 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Locations RH Door Harness (LH Typical) Page 4515 Transmission Speed Sensor: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Page 715 CMFI Intake Manifold Sensors/Valves Page 6376 ^ PAG oil used for future service if needed (mark PAG on box on label, Figure 6). ^ HR6 or R4 original compressor RETAINED - add 8 oz FAG oil to system ^ V5 original compressor RETAINED - add 9 oz V5 Retrofit oil to system. If V5 Retrofit oil is not available from GMSPO, REPLACE THE COMPRESSOR. c. Based on the above chart, add oil if needed. Use the new oil bottle and the extended tube kit, J 39500-71. Fill the bottle with at least 10 oz of oil. Attach the new bottle to the back of the ACR4, and open the oil fill valve. Allow the correct amount of oil to be drawn into the system. DO NOT allow the oil level to drop below the end of the pickup tube. This will prevent any air from being drawn into the system. If any oil was removed during the R-12 recovery evacuation steps, DO NOT add additional oil to replace it. d. Determine the correct amount of R-134a to use. Check the existing label of the vehicle for the R-12 charge amount. Use the formula {(R12 x .9) - .25 lb = R-134a} to determine the correct charge. This can also be stated as: Take 90% of the R12 charge, and subtract 1/4 lb. Follow the directions for the ACR4 cart to recharge the system. At the end of the process, "CPL" will be displayed. Close the high side valve. e. Start the vehicle, turn on the A/C system, and confirm that pressures are within normal operating ranges, as shown in the 1994 Service Manual. The 1994 Service Manuals can be used as a reference for diagnosis and specification of retrofitted systems. On some vehicles with automatic A/C controls or low charge diagnostics, the A/C compressor may not engage if any diagnostic codes were set during the retrofit. Check to see if any codes were set in either the HVAC or Engine Control systems. If they were, clear the codes following the directions in the Service Manual. Page 6247 - Install J 23128-A and the seal (13) over the compressor shaft (39). - Push the seal (13) into place with a rotary motion. Important - Do not dislodge the seal (O-ring) (15). 4. Shaft seal seat retaining ring (12) with J 5403. - Place the flat side against the seal seat. - Use the sleeve of J 23128-A to press the ring into its groove. 5. J 9625-A to the rear head of the compressor: - Gage charging lines or pressurize the suction side (low pressure side) of the compressor with refrigerant to equalize the pressure to the drum pressure. 6. New absorbent sleeve (11). - Roll the material into a cylinder, overlapping the ends. - Slip the sleeve into the compressor front head with the overlap toward the top of the compressor. - With a screwdriver spread the sleeve ends of the sleeve butt at the top vertical centerline. 7. Sleeve retainer (10) with J 9393-A. - Place the flange face against the front end of the sleeve. Shaft/Seal Position And Correct Position Gaging Guide - Press and tap with a mallet to set the retainer and sleeve into place. Place the retainer 0.7937 mm (0.03125-inch) from the face of the compressor neck. 8. Clutch plate and hub assembly (2). Important Using improper procedures, pounding or collisions can damage the shaft seal and the axial plate. If the axial plate is out of position, the carbon face of the shaft seal may not contact the seal seat. Windshield/A Pillar - Pop Noise Diagnosis Windshield: All Technical Service Bulletins Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Page 7609 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 2122 Spark Plug Wire: Description and Operation CONSTRUCTION The spark plug/coil secondary wiring is a carbon impregnated cord conductor encased in a rubber jacket. The 7-mm wire used on the 2.5L and 2.8L engines and the 8-mm wire used on the 3.1L, 4.3L, 5.0L, 5.7L and 7.4L has an outer layer of silicone. The silicone jacket withstands very high temperature and also provides an excellent insulator for the higher voltage of the electronic ignition system. The silicone spark plug boots form a tight seal on the plugs and distributor cap. CAUTION - Care should be exercised when connecting a timing light or other pick-up equipment. - Do not force anything between the boot and wiring. - Do not pierce the secondary wire insulation. - Use only equipment with an inductive pickup to check for spark plug firing. - Do NOT pull on the wire to remove. The boot should be twisted 1/2 turn before removing. Pull on the boot, or use a tool designed for this purpose. Page 4115 Valve Body: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. FWD Accumulator Cover To Valve Body ............................................................................................ ............................................................................... 8 Valve Body To Case ......................................... .............................................................................................................................................................. ..... 8 Pressure Control Solenoid To Valve Body ................................................................................. ......................................................................................... 8 Detent Spring To Valve Body ................. .............................................................................................................................................................. ............. 18 Auxiliary Valve Body To Case .......................................................................................... .................................................................................................. 8 Intake Air Temperature (IAT) Sensor Intake Air Temperature (IAT) Sensor 4.3W Page 4734 ^ Right rear ^ Left rear ^ Right front ^ Left front Note: Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. Note: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 4. Slowly apply the brake pedal one time and hold. 5. Loosen the bleeder valve to purge the air from the wheel cylinder/caliper. 6. Tighten the bleeder valve and slowly release the pedal. 7. Wait 15 seconds. 8. Be sure to check the master cylinder fluid level after 4-5 strokes to avoid running dry. 9. Repeat steps 4 through 8, until all air is purged from the wheel cylinder/caliper. Note: It may be necessary to repeat this sequence as many as 15 to 20 times per wheel. 10. Fill the master cylinder to the proper level and replace lid. 11. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs.in.). 12. Remove the valve pressure bleeding tools J 39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 13. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. Important DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 14. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. Important DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 15. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs. in.). 16. Fill the master cylinder to the proper level with brake fluid. 17. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. Important MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 18. Repeat the entire brake bleed procedure if necessary. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation: H0700 Labor Time: See applicable labor time guide Note: When performing the 4WAL brake system bleeding procedure. the ignition switch must be in the "OFF" position or false diagnostic trouble codes could be set to memory. If trouble codes are set, refer to Section 5E1 "Clearing Diagnostic Trouble Codes" in the 1993 Service Manual. PRESSURE BLEED PROCEDURE Page 352 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 756 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 2049 - Use care when engaging the front of the oil pan seal with the bottom of the front cover. Lubricate the front of the oil pan seal with engine oil to aid assembly. 16. Crankshaft front oil seal to the front cover. Use J 35468. 17. Oil pan bolts, nuts, and reinforcements. 18. Flywheel inspection cover. 19. Torsional damper. Use J 23523-E. 20. Coolant pump. 21. Pencil brace to coolant pump. 22. Multiple ribbed belt. 23. Fan assembly. 24. A/C condenser. 25. Radiator. 26. Lower radiator hose. 27. Heater hose and overflow hose to radiator. 28. Upper radiator hose. 29. Transmission cooler lines to the radiator. 30. Oil cooler lines to the radiator. 31. Upper radiator shroud. 32. Air cleaner and air intake duct. 33. Negative battery cable. - Fill crankcase with proper quantity and grade of engine oil. - Fill cooling system with proper quantity and grade of coolant. Page 4782 Hydraulic Assembly: Service and Repair Four Wheel Anti-Lock Brake System The EHCU/BPMV module is not serviceable and must be replaced as a unit. Fig. 54 EHCU/BMPV Mounting. Astro/Safari Refer to Fig. 57 when replacing this unit. 1. Remove washer tank attaching bolts, then position aside. 2. Remove EHCU/BPMV electrical connectors. 3. Disconnect module brake lines. Use caution not to get brake fluid on paint or electrical connections. 4. Remove upper to lower bracket assembly attaching bolts. 5. Remove EHCU/BPMV module and upper bracket assembly from vehicle. 6. Remove upper mounting bracket to EHCU/BPMV module attaching bolts. 7. Reverse procedure to install, noting the following: a. Torque EHCU/BPMV module to bracket attaching bolts to 5 ft. lbs. b. Torque EHCU/BPMV bracket assembly attaching bolts to 20 ft. lbs. c. Torque brake line fittings to 16 ft. lbs. d. Bleed EHCU/BPMV module as outlined under MAINTENANCE PROCEDURES/BLEEDING EHCU/BPMV MODULE. Page 6421 Make sure the vehicle compressor is engaged. Turn the cart on and start the recovery cycle. OPEN ONLY THE HIGH SIDE VALVE ON THE GAUGE SET. The vehicle system should eventually shut the compressor off. If the low side pressure drops below 15 psi, and the compressor does not turn off, turn it off now (go to "VENT" or "ECON" mode), but leave the engine running and the blower on "high". c. After the recovery cart shuts off the first time, wait 5 minutes. If the pressure on either the high or the low side rises above 0 psi, restart the recovery process. After the second shutoff, wait 2 minutes. If the pressure again rises above 0 psi, restart, and after shutoff, again wait 2 minutes. The process can be stopped when the pressure does not rise above 0 psi after 2 minutes. The engine can be shut off at this time. d. Remove the R-12 reclaim hose and the gauge set from the vehicle. Any repairs needed should be done at this time. If any components other than the compressor are replaced, they should be installed dry, and no extra oil should be added. 3. Install the Service Port Conversion Fittings Important: For GEO vehicles, skip to Step 4. Fitting installation is covered in that step. For vehicles that require a HPCOS, see Step 4. Some of these vehicles use a specific combination fitting to mount the HPCOS, which includes the high side service port fitting and the HPCOS port. The low side fitting is installed as detailed below. See "Platform Details" for further information. Important: A new tool kit, P/N J 39500-250, has been released. This kit contains the following items: ^ J 39500-71 Oil Injection Bottle Conversion Kit (includes 3 12 oz bottles, an extender tube, caps, and fittings) ^ J 39500-275 Tool kit, including the following: (See Figure 2) - J 34611-A Double ended valve core remover - J 25498-A High side adapter fitting - J 38702 Deep valve core adapter fitting Page 7186 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 1379 2. Fill the injury (puncture) to keep moisture out. 3. Seal the inner liner with a repair unit to prevent air loss. External Inspection 1. Prior to demounting, inspect the tire surface, the valve and the wheel for the source of the leak by using a water and soap solution. Mark the injured area and totally deflate the tire by removing the valve core. 2. Demount the tire from the wheel and place the tire on a well-lighted spreader. Internal Inspection 1. Spread the beads and mark the puncture with a tire crayon. 2. Inspect the inner tire for any signs of internal damage. 3. Remove the puncturing object, noting the direction of the penetration. 4. Probe the injury with a blunt awl in order to determine the extent and direction of the injury. 5. Remove any loose foreign material from the injury. 6. Punctures exceeding 6.35 mm (1/4") should not be repaired. Cleaning 1. Clean the area around the puncture thoroughly with a proper liner cleaner, clean cloth and a scraper. This step serves to remove dirt and mold lubricants to insure proper adhesion and non-contamination of the buffing tool. 2. Refer to information on the product or manufacturer's Material Safety Data Sheet and follow guidelines for handling and disposal. Clean the Injury Channel Page 1612 To eliminate the noise, use the appropriate procedure below. In determining which procedure is appropriate, inspect the engine identification number stamped on the engine block. The attached diagrams show the location of the engine identification number on the block. Use Procedure 1 for engines with a "W" in the source code location (first position). Use Procedure 2 for engines with a "T" in the source code location. Procedure 1 For LB4 engines with a "W" in the source code location. These engines have pressed-in studs and an adjustable lash valvetrain. Unlash all intake and exhaust valves. Using the valve lash procedure outlined in the service manual, lash the valves in 1.75 turns down from zero lash (not 1 turn). Procedure 2 For L35 engines or LB4 engines with a "T" in the source code location. These engines have screw-in studs and a net lash valvetrain. Remove old rocker arm nuts, rocker arms, rocker balls, and studs from the cylinder head and discard. Install adjustable lash service studs P/N 476530. Page 1160 Page 8531 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 3897 Page 2523 Knock Sensor: Description and Operation Electronic Spark Control Circuit Knock Sensor (KS) Sensor PURPOSE Varying octane levels in today's gasoline can cause detonation (also known as spark knock) in an engine. The Knock Sensor (KS) system has various knock sensors that are used on all engines except the 2.5L. The KS system reduces spark knock (detonation) in the engine. This allows the engine to have a maximum spark advance for improved driveablity and fuel economy. CONSTRUCTION This KS system has three main components: - KS Module. - Knock sensor - ECM OPERATION The knock sensor detects abnormal vibration (spark knocking) in the engine. The knock sensor is mounted in the engine block near the cylinders. The KS module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the Ignition Control (IC) to reduce spark knocking. The KS module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the knock sensor. This allows the ECM to maintain maximum timing advance under various engine load conditions. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards IC to reduce spark knock. Page 8534 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 2255 Parts Information Parts are currently available from GMSPO. M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot Pilot Bearing: Customer Interest M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot BULLETIN NUMBER: 92-7B-149A SECTION: 7B Manual Transmission NUMBER: 1 CORPORATE REFERENCE NUMBER: 2672O1R DATE: August 1993 SUBJECT: NEUTRAL GEAR RATTLE (REPLACE CLUTCH DISK, PROM AND PILOT BUSHING) MODELS: 1990-92 C/K AND 1990-92 S/T WITH 4.3L AND 5 SPEED MANUAL TRANSMISSION This bulletin cancels and replaces Truck Bulletin 92-7B-149 (corp. # 267201R) dated December 1992, and is being revised to add the 1992 model year S/T Trucks with 4.3L engines (RPO LB4) and to add the "Detonation and Neutral Gear Rattle Proms" section. CONDITION Some owners of 1990-92 C/K and 1990-92 S/T Trucks with 4.3L engines (RPO LB4) and 5-speed manual transmission (RPO's MG5, MY2) may comment that the transmission rattles when in neutral with their foot off the clutch pedal and the engine at idle. The customer may describe the rattle as loose bearings. CAUSE This rattle noise is created when the turning transmission gears contact against each other. The contact is created by the firing impulses of the engine which causes rapid acceleration and deceleration of the individual gears. CORRECTION This condition may be corrected by the installation of the following parts: - A revised clutch driven disc which features a live degree neutral stage. This neutral stage helps to smooth the rapid acceleration and deceleration of the individual transmission gears. - A revised PROM which raises engine idle speed to 650 RPM on C/K and 700 RPM on S/T. This increase in idle speed helps to smooth the engine firing pulses. - A clutch pilot bearing rather than a clutch pilot bushing. This bearing helps to isolate the transmission from the engine idle acceleration/deceleration. SERVICE PROCEDURE Important Incorrect engine idle can contribute to neutral gear rattle. Before installing the parts listed in this bulletin, refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 2, Driveability Symptoms "Rough, Unstable or Incorrect Idle Stalling" to verify there are no existing conditions contributing to a rough idle which may aggravate neutral gear rattle. Clutch Disc and Pilot Bearing Replacement: Refer to the appropriate year and model Service manual, Section 7C "Clutch Assembly and Pilot Bearing Replacement." Important C/K trucks require pressure plate P/N 15974649 which was first used in production mid-1991. 1990 and 1991 vehicles built prior to the following VIN breakpoints require installation of P/N 15974649 unless it has already been installed in a service repair: Ft. Wayne (Z) MZ516555 Oshawa (1) M1526826 Pontiac (E) ME51G465 PROM Replacement: Refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 3 "On-Vehicle Service, PROM". Page 8142 Stoplamp Switch Installation Page 5181 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Spark Plugs - Revised Spark Plug: Technical Service Bulletins Spark Plugs - Revised Number: 93-03-6D Section: 6D Date: AUGUST 1992 Corporate Bulletin No.: 166001R ASE No.: Al, A6, A8 Subject: NEW DESIGN SPARK PLUGS Model and Yew: 1991-93 ALL PASSENGER CARS AND TRUCKS WITH GASOLINE ENGINES THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO., 91-234A-OB, DATED JULY 1992. THE 1992 AND 1993 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 91-234A-OB SHOULD BE DISCARDED. In 1991 GM introduced a new design spark plug for use in all trucks equipped with gas engines. These new design spark plugs have a ceramic insulator which is approximately 1/8 inch longer than the insulator used in previous model years. The longer length spark plugs, which conform to S.A.E. and I.S.O. Engineering guidelines, magnify the problem of cracked insulators because currently, most spark plug sockets are not of sufficient length to properly engage the shell hex. If the spark plug shell hex is not fully engaged in the spark plug socket wrench, the socket may cock at an angle and cause insulator cracking and/or breakage during plug installation or removal. When servicing these new design spark plugs, make sure that the spark plug socket being used is deep enough to accommodate the longer length insulator. The spark plug socket wrench should conform to the proposed S.A.E. and I.S.O. world standards for spark plug socket wrenches. Spark plug socket wrenches that conform to these standards are designed to accept the lengthened spark plugs and allow full engagement of the hex nut on the shell of the spark plug. Use of a spark plug socket which is NOT deep enough may result in the ceramic insulator becoming cracked above the spark plug shell. Note: SOME CRACKS IN THE INSULATOR M" NOT BE VISIBLE. SUCH CRACKS MAY LATER CAUSE A SPARK PLUG TO MISFIRE. SPARK PLUG MISFIRES ARE OFTEN MISDIAGNOSED AS A SLIPPING TRANSMISSION, DEFECTIVE TORQUE CONVERTER CLUTCH, ENGINE IMBALANCE, OR MALFUNCTIONING FUEL SYSTEM. To prevent insulator damage, it is recommended that the proper spark plug socket wrench be used when removing or replacing spark plugs. One such spark plug socket is the Kent-Moore J-39358 spark plug socket. The tool is available from Kent-Moore. For ordering information call 1 -800-345-2233 or write: Kent-Moore SPX Corporation 39784 Little Mack Roseville, MI 48066-2298 Fax: 313-774-9870 Page 4130 SERVICE PARTS INFORMATION WARRANTY INFORMATION Page 6663 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 6749 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 390 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Diagram Information and Instructions Brake Vacuum Release Valve: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 5431 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 3751 Prom Information Scan Prom Prom Prom Superseding ID Code Bcc Part # ID Part # TSB Reference # 1111 1250 BCBC 16181249 Chevrolet 236111 Center Port Fuel Injection noise (may require engine GMC Truck 236111 exchange). 1121 1257 BCBD 16181255 Chevrolet 236111 Center Port Fuel Injection noise (may require engine GMC Truck 236111 exchange). 1131 1262 BCBF 16181261 Chevrolet 236111 Center Port Fuel Injection noise (may require engine GMC Truck 236111 exchange). 1141 1278 BCBH 16181277 Chevrolet 236111 Center Port Fuel Injection noise (may require engine GMC Truck 236111 exchange). Oldsmobile 236111 1151 1282 BCBJ 16181281 Chevrolet 236111 Center Port Fuel Injection noise (may require engine GMC Truck 236111 exchange). 2251 7054 AURB 16157053 2261 7090 AURC 16157089 2271 7094 AURD 16157093 2281 7099 AURF 16157098 2291 7103 AURH 16157102 2301 7108 AURJ 16157107 2321 7117 AURL 16157116 2331 7121 AURM 16157120 8631 16168590 2341 7126 AURN 16157124 8641 16168596 2351 7130 AURP 16157129 8651 16168600 2361 7134 AURR 16157133 8661 16168605 2371 7139 AURS 16157138 2381 7143 AURT 16157142 4761 4787 BALD 16174786 Running change. 4771 4792 BALF 16174790 Running change. 4781 4796 BALH 16174795 Running change. 4791 4800 BALJ 16174799 Running change. 4801 4805 BALK 16174804 Page 8217 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 1153 Use the octagon sockets on the straight fittings (J 39037 high side, and J 41256 low side). Torque the new fitting until it seats. The fitting should seat fully BEFORE reaching 11 N.m (8 lb ft). If 11 N.m (8 lb ft) of torque is reached and the fitting has not seated, it is probable that the threads have been damaged. In this case, remove the fitting and use the thread restorer listed above. Reinstall the fitting, adding one drop of a thread locking compound such as Loctite(R) 242. The fittings (except the two-piece) have a thread locking compound applied to the threads. This compound will set up enough to restrict removal of the fitting in about 15 minutes. The fittings can now be used to evacuate the system (see Step 5). An additional type of conversion port fitting has been developed. This fitting is called a saddle clamp valve (see Figure 5). It can be clamped directly on a metal refrigerant line, and will be used if the existing fitting is damaged or is inaccessible. A drop of a thread locking compound, such as Loctite(R) 242, should be used on each bolt to prevent the threads from loosening. The R134a saddle clamp valve part numbers are: If an existing R-12 service port is not used, it must be rendered inoperative. Place several drops of a thread locking compound, such as Loctite(R) 243, in the valve core, and onto the cap threads. Secure the cap and let it set for 15 minutes. 4. Install Any Additional Parts Needed See "Platform Details" after Step 6. If a vehicle is listed as a "Basic Retrofit", no additional parts are required (except for compressors, see the Compressor Replacement Chart at the beginning of Platform Details). If no parts are required, PROCEED TO STEP 5. Compressors Compressors do not need to be replaced as part of a normal retrofit, unless indicated in the Compressor Replacement Chart. An R-12 compressor that is operating properly can, in most cases, be left in the vehicle when it is retrofitted to R134a. However, if a compressor failure is the reason the vehicle is in for service, and the vehicle will be retrofitted, OR if a vehicle has already been retrofitted with R-134a and the compressor fails at some time in the future, new compressors for use with R-134a are available. See the GMSPO Parts Catalog for specific part numbers. DO NOT use a replacement R-12 compressor for any vehicle retrofitted to R-134a (unless it is the new "oil-less" design). See "Compressor Availability" at the end of the Compressor Replacement Chart. Accumulator /Dryer If the vehicle is more than 5 years old, the Accumulator/Dryer (A/D) should be replaced to ensure that moisture is removed from the system. See the instructions for proper A/D identification in General Information. High Pressure Cut-Off Switch (HPCOS) Most trucks, and some 1984-93 B and D cars, require that a HPCOS be added to protect the refrigerant system during long idles at high temperature. The HPCOS kit (P/N 15981985) contains the switch, wire harness, heat sealing splice connectors, switch "0" ring, and installation instructions. A saddle clamp adapter (P/N 15985307), or a special dual fitting, is mounted to the high pressure line, and provides the port to mount the switch. A drop of a Page 347 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 5121 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 6753 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Locations Engine Wiring, LH Side Page 2949 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Page 2916 Coolant Temperature Sensor/Switch (For Computer): Description and Operation ECT Circuit (Typical) Engine Coolant Temperature Sensor PURPOSE Engine Coolant Temperature (ECT) Sensor is used to control: Exhaust Gas Recirculation (EGR) - Fuel delivery - Idle Air Control (IAC) - Ignition Control (IC) - Torque Converter Clutch (TCC) OPERATION The ECT sensor is a thermistor that is located in the engine coolant flow. Low coolant temperature sensor produces a high resistance (100,000 ohms at -40°C/-40°F). High coolant temperature, produces a low resistance (70 ohms at 130°C/266°F). The control module sends a 5.0 volt signal to the ECT through a resistor in the control module and measures the voltage. The voltage will be high when the engine is cold and low when the engine is hot. Engine coolant temperature affects most systems controlled by the control module. The control module uses information from the ECT to calculate spark advance as follows: Cold engine results in more spark advance. - Hot engine results in less spark advance. Page 5472 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 1212 being done. Important: During 1996, "oil-less" compressors began to be serviced with NO added oil. New part numbers will be issued, and both the box and the compressor will be clearly marked to indicate that no oil is present. If you receive one of these newer compressors, simply add the normal amount of oil to the system in Step 5 of the retrofit procedure (8 oz of PAG oil, or 9 oz of PAG oil with V5 compressor). These "oil-less" compressors are compatible with EITHER R12 or R-134a. Geo Models Compressors DO NOT HAVE TO BE REPLACED as part of the retrofit. New compressors are shipped with enough oil to accommodate the entire A/C system. Do not add additional PAG oil to the system it the compressor is being replaced. 1985-88 Nova, 1989-93 Prizm (S) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Loosen evaporator to compressor (suction) pipe (to be reinstalled) c. 1985-92 only: Loosen compressor to condenser (compressor discharge) pipe (to be reinstalled). d. 1985-88 only: Service Valve & Extension Housing on compressor (to be installed). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. 1985-88 only: Service Valve & Extension Housing on compressor using new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe 0-ring. e. 1985-92 Compressor to condenser (discharge) hose 0-ring. f. Receiver/dryer and 0-rings. R-134a amount: 85-92 - 650 grams (1.43 lb) 93 - 700 grams (1.54 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-88 - 94855761 89-93 - 94855762 Adapter Fittings: Low Side - 94855760 High Side - 94855759 0-Rings: 85-88 Compressor - Small 0-rings (6 required) - 94857336 - Large 0-ring - 94857337 85-93 Receiver/Dryer (2) - 94845949 Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Page 8118 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Description Parking Lamp: Description and Operation Description Voltage is applied through the TAIL LPS Fuse to the Light Switch at all times. With the Lamp Switch in PARK or HEAD, voltage is applied to the Park, Tail, Marker and License Lamps. Page 3764 PROM - Programmable Read Only Memory: Service and Repair MEMCAL CONDITION: When installing a service replacement computer, the use of incorrect MEMCAL installation procedures may cause the computer to fail before it can be installed in the vehicle. This condition may appear as if the computer were defective when shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an updated MEMCAL into the vehicles original equipment computer. CAUSE: Excessive vertical force may be applied to the MEMCAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive vertical force may be generated in two ways. ^ Incorrect MEMCAL installation procedures. ^ Interference between MEMCAL and cover. IMPORTANT CORRECTION: This procedure supersedes any instructions regarding MEMCAL installation dated prior to September 1990. 1. Inspect the MEMCAL to determine if a cork spacer is glued to the top side of the MEMCAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in Computer MEMCAL socket. 3. VERY GENTLY PRESS down on the ends of the MEMCAL until the locking levers are rotated toward the sides of the MEMCAL. NOTE: To avoid computer damage, do not press on the ends of the MEMCAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEMCAL into its socket. 4. While continuing light pressure on the ends of the MEMCAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for the click. 5. Install MEMCAL cover and install computer cover. Page 3546 Distributor: Description and Operation Distributor Reference Signal PURPOSE The distributor reference signal provides the control module with both engine RPM and crankshaft position information. This enables the control module to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the control module receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the control module will not operate the injector. Page 7473 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Locations Engine Wiring, LH Side Page 6590 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 51 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Upper Control Arm Bushing Control Arm Bushing: Service and Repair Upper Control Arm Bushing Fig. 4 Upper Control Arm Bushing Removal. 4 X 2 Models Fig. 5 Upper Control Arm Bushing Installation. 4 X 2 Models 4 X 2 MODELS 1. Remove upper control arm as described under UPPER CONTROL ARM. 2. Remove nuts from end of pivot shaft, then remove bushings, Fig. 4. 3. Install bushings by installing pivot shaft in control arm and pressing new bushings into control arm, Fig. 5. Torque pivot shaft nuts to specifications, with weight of vehicle resting on wheels. Both bushings must be installed .48-.52 inch from face of control arm to bushing outer sleeve. 4 X 4 MODELS 1. Remove upper control arm as previously outlined under UPPER CONTROL ARM. 2. Refer to Fig. 4 and 5, for bushing removal and installation. Page 5705 Drilling The Ball Joint Rivets Installing The Upper Ball Joint SPECIAL TOOLS REQUIRED (or equivalents) ^ J-23742, Ball joint separator. REMOVE OR DISCONNECT 1. Raise the vehicle and support the lower control arm with floor stands. Since the weight of the vehicle is used to relieve the spring tension on the upper control arm, the floor stands must be positioned between the spring seats and the lower control arm ball joints for maximum leverage. WARNING: Floor jack or stand must remain under the control arm spring seat during removal and installation to retain the spring and control arm in position. Failure to do so could result in personal injury. 2. Wheel and tire assembly. 3. Caliper and support caliper with a piece of wire to prevent damage to the brake line. 4. Cotter pin (68) and stud nut (67) from the upper ball joint (66). 5. Using J-23742, apply pressure on the tool until the stud breaks loose from control arm. 6. J-23742 and pull the stud away from the knuckle. Support the knuckle assembly so that its weight will not damage the brake hose. 7. Rivets from the upper ball joint. a. Use a 3.175 mm (118-inch) drill to cut a 6.35 mm (114-inch) deep hole in the center of each rivet. b. Drill the rivet heads away using a 12.7 mm (112-inch) drill. c. Punch the rivets out using a small pin punch. 8. Upper ball joint. INSTALL OR CONNECT 1. New upper ball joint (66) to the upper control arm (42). CAUTION: When fasteners are removed, always reinstall them at the same location from which they were removed and use the correct torque value. If a fastener needs to be replaced, use a fastener of the correct size and strength. Failure to do so may result in component/system damage or malfunction. 2. Position four attaching bolts and nuts and tighten to 23 Nm (17 ft lbs). Take the support away from the knuckle assembly. 3. Upper ball joint to the steering knuckle. 4. Stud nut (67) and tighten to 83 Nm (61 ft lbs). Align the slot in the stud nut with the hole in the stud by tightening the stud nut. Page 1163 85-93 Suction hose - 94855765 85-92 Discharge hose - 94845943 1985-88 Sprint, 1989-93 Metro (M) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 500 grams (1.10 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-86 - 91172081 87-88 - 91172079 89-93 - 96068480 Adapter Fittings: Low Side - 91172092 85-88 - High Side - 91172094 89-93 - High Side - 52467941 0-Rings: Compressor - Small 0-rings (6 required) - 91172095 - Large 0-ring - 96068915 Receiver/Dryer (2) - 96068488 Page 4300 Important: If the original pre-load torque value was < (less than) 3 lb.in., then reset torque specifications to 3-5 lb.in. Important: If the pinion seal and collapsible spacer are replaced, then refer to the appropriate Unit Repair Manual of pinion re-load specifications. 4. Install the "Dual Double Cardon" two piece propeller shaft and attaching bolts and nuts. 5. Apply a coating of GM P/N 12345382 Thread Lock or Loctite(R) # 242 or equivalent to the mounting bolt threads to flange. Tighten Tighten bolts to 50 Nm (37 lb.ft.). 6. Install the rear axle brake drum and wheel assemblies. 7. Add lubricant to the rear axle as necessary. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty. Page 8573 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 5942 Blower Motor Replacement Blower Motor: Service and Repair Blower Motor Replacement With A/C Evaporator And Blower Assembly Component View REMOVE OR DISCONNECT 1. Electrical connectors, as necessary. 2. Screws (26). 3. Blower motor (45). 4. Blower motor fan. INSTALL OR CONNECT 1. Blower motor fan. 2. Blower motor (45). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 3. Screws (26). 4. Electrical connectors, as necessary. Without A/C Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Page 2915 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature (ECT) Sensor Engine Coolant Temperature (ECT) W Engine Wiring, RH Side Locations Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Page 7816 Use applicable labor time guide for labor hours. Locations Timing Connector Page 7590 Figure 7 Figure 8 Figure 9 Figure 10 Page 4597 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 1454 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These Page 1380 1. Use a proper hand reamer, carbide cutter or drill bit to ream the puncture channel from the inside of the tire in order to clean the injury. 2. Remove steel wires protruding above the liner surface to prevent damage to the repair unit. 3. Consult your repair material supplier for recommended reaming tool(s). Fill the Injury 1. It is necessary to fill the injury channel to provide back up for the repair unit and to prevent moisture from entering the tire fabric and steel wires. 2. (For combination repair/plug units skip this step.) Cement the injured channel and fill the injury from the inside of the tire with the repair plug per repair material manufacturer's recommendations. Without stretching the plug, cut the plug off just above the inside tire surface. 3. Consult your repair material supplier for proper repair material selection. Repair Unit Selection Important Do not install the repair unit in this step. Initial Inspection and Diagnostic Overview Driver Information Center (DIC): Initial Inspection and Diagnostic Overview 1. Check condition of IGN/GAU, BRAKE and INST LPS Fuse(s). If fuse(s) s blown, locate and repair source of overload. Replace fuse(s). Locations Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Page 809 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Service and Repair Push Rod: Service and Repair 1. Disconnect battery ground cable. 2. Remove air cleaner assembly, then the emission relays and bracket. 3. Remove wiring harnesses and spark plug wires from clips and position aside. 4. Disconnect dipstick tube from cylinder head and position tube aside. 5. Remove rocker arm cover. 6. Remove rocker arm nut, then rocker arm and ball. 7. Remove pushrod. 8. Reverse procedure to install. Adjust valves as described under ADJUSTMENT PROCEDURES/VALVES. Page 6817 Parts Information Parts required to complete this special coverage are to be obtained from General Motors Service and Parts Operations (GMSPO). Customer Notification General Motors will notify customers of this special coverage on their vehicles. Service Procedure Replacement of interior door handle assembly(s) Provide the customer with one or two interior front door handle assemblies. The customer is to self-install the assemblies or pay the dealer for the installation. Application of Lithium Grease Apply lithium based lubricant to the door handle springs. The lubricant should be applied so that it works into and between the spring coils, allowing the coils to move past each other freely. Claim Information Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Page 7910 Diagram Information and Instructions Speaker: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 7679 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 4547 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Locations Timing Connector Page 2852 CHANGES TO MEMCAL/PROM LABELING FORMATS ^ MEMCALs may use either INK-JET or ADHESIVE labels, as shown. ^ PROMs will always use ADHESIVE labels with the same format as shown for MEMCALs. These changes will become effective on parts manufactured after 10/94. Valve Specifications Valve: Specifications Stem Diameter Standard Intake 0.3410-0.3417 in Exhaust 0.3410-0.3417 in Maximum Tip Refinish Note: Grind only enough lo provide true surface. After grinding valve stems, ensure sufficient clearance remains between rocker arm & valve spring cap or rotator Face Angle 45 deg Margin Intake 0.0315 in Note: Minimum Exhaust 0.0315 in Page 404 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 3382 Diagnostic Circuit Circuit Description The diagnostic circuit check is an organized approach to identifying a problem created by an electronic engine control system malfunction. It must be the starting point for any driveability complaint diagnosis, because it directs the service technician to the next logical step in diagnosing the complaint. Understanding the chart and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of good parts. Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. This step is a check for the proper operation of the "Service Engine Soon" light. The "SES" light should be "ON" steady. 2. No "SES" light at this point indicates that there is a problem with the "SES" light circuit or the control module control of that circuit. 3. This test checks the ability of the control module to control the "SES" light. With the diagnostic terminal grounded, the "SES" light should flash a Code 12 three times, followed by any trouble code stored in memory. A PROM error may result in the inability to flash Code 12. 4. Most of the diagnostic charts use a Tech 1 to aid diagnosis, therefore, serial data must be available. If a PROM error is present, the control module may have been able to flash Code 12 or 51, but not transmit serial data. 5. Although the control module is powered up, a "Cranks But Will Not Run" symptom could exist because of an control module or system problem. 6. This step will isolate if the customer complaint is a "SES" light or a driveability problem with no "SES" light. Refer to Computers and Control Systems for a list of valid codes. An invalid code may be the result of a faulty "Scan" tool, PROM or control module. See: Computers and Control Systems 7. Comparison of actual control system data with the typical valves is a quick check to determine if any parameter is not within limits. Keep in mind that a base engine problem (i.e., advanced cam timing) may substantially alter sensor values. 8. If the actual data is not within the typical values established, refer to Computers and Control Systems. See: Computers and Control Systems Page 6912 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 3786 Torque Converter Clutch Solenoid: Locations Torque Converter Clutch Solenoid (TCC) Inside automatic transmission attached to valve body. Page 2385 Fig. 4 Thermostat Diagnosis Specifications Idle Speed: Specifications CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Auto D 550 5-40 CL [1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). Page 5671 Fig. 5 Inner tie rod installation Installation 1. Install shock dampener, then inner tie rod and tighten to specifications. 2. Ensure tie rod rocks freely in housing. Stake both sides of tie rod housing to flats on rack, Fig. 5. 3. Check both stakes by inserting .010 inch feeler gage between rack and tie rod housing as shown in Fig. 5. Feeler must not pass between rack and housing stake. 4. Slide shock dampener over housing until it engages, then install pinion boot and new clamp. 5. Apply grease to tie rod and housing. Install boot onto tie rod and up to housing. 6. Align breather tube with mark made during removal. Connect elbow of boot to breather tube. 7. Crimp boot clamp onto boot and position tie rod end clamp with pliers on boot. 8. Install hex jam nut onto inner tie rod, then install outer tie rod. Pinion Seal, Dust Seal & Bearing Fig. 2 Bearing adjustment Page 8388 Forward Lights Harness, RH Side M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot Pilot Bearing: All Technical Service Bulletins M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot BULLETIN NUMBER: 92-7B-149A SECTION: 7B Manual Transmission NUMBER: 1 CORPORATE REFERENCE NUMBER: 2672O1R DATE: August 1993 SUBJECT: NEUTRAL GEAR RATTLE (REPLACE CLUTCH DISK, PROM AND PILOT BUSHING) MODELS: 1990-92 C/K AND 1990-92 S/T WITH 4.3L AND 5 SPEED MANUAL TRANSMISSION This bulletin cancels and replaces Truck Bulletin 92-7B-149 (corp. # 267201R) dated December 1992, and is being revised to add the 1992 model year S/T Trucks with 4.3L engines (RPO LB4) and to add the "Detonation and Neutral Gear Rattle Proms" section. CONDITION Some owners of 1990-92 C/K and 1990-92 S/T Trucks with 4.3L engines (RPO LB4) and 5-speed manual transmission (RPO's MG5, MY2) may comment that the transmission rattles when in neutral with their foot off the clutch pedal and the engine at idle. The customer may describe the rattle as loose bearings. CAUSE This rattle noise is created when the turning transmission gears contact against each other. The contact is created by the firing impulses of the engine which causes rapid acceleration and deceleration of the individual gears. CORRECTION This condition may be corrected by the installation of the following parts: - A revised clutch driven disc which features a live degree neutral stage. This neutral stage helps to smooth the rapid acceleration and deceleration of the individual transmission gears. - A revised PROM which raises engine idle speed to 650 RPM on C/K and 700 RPM on S/T. This increase in idle speed helps to smooth the engine firing pulses. - A clutch pilot bearing rather than a clutch pilot bushing. This bearing helps to isolate the transmission from the engine idle acceleration/deceleration. SERVICE PROCEDURE Important Incorrect engine idle can contribute to neutral gear rattle. Before installing the parts listed in this bulletin, refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 2, Driveability Symptoms "Rough, Unstable or Incorrect Idle Stalling" to verify there are no existing conditions contributing to a rough idle which may aggravate neutral gear rattle. Clutch Disc and Pilot Bearing Replacement: Refer to the appropriate year and model Service manual, Section 7C "Clutch Assembly and Pilot Bearing Replacement." Important C/K trucks require pressure plate P/N 15974649 which was first used in production mid-1991. 1990 and 1991 vehicles built prior to the following VIN breakpoints require installation of P/N 15974649 unless it has already been installed in a service repair: Ft. Wayne (Z) MZ516555 Oshawa (1) M1526826 Pontiac (E) ME51G465 PROM Replacement: Refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 3 "On-Vehicle Service, PROM". Page 1542 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Starter Models 1998440 - 9000735 Starter Solenoid: Specifications Hold-In Windings And Pull-In Windings Amperes Hold-In Windings And Pull-In Windings Amperes Hold-In Windings Pull-In Windings Starter Identification Number 1998440 13-18 A 11-18 A 1998559 13-19 A 23-30 A 1998583 13-19 A 23-30 A 1998584 13-19 A 23-30 A 1998588 14-18 A 26-30 A 1998589 14-18 A 26-30 A 9000735 13-15 A 31-36 A Page 6648 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7528 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 3745 [270] Cold driveability, use with PROM 5860 KK (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. [271] Tip-in hesitation, lack low speed performance. Used with Manual transaxle vehicles with A/C only. Requires EGR TVS P/N 373510, and A.I.R. valve P/N 17082701. [272] Weak drive-away after cold start, requires EGR TVS P/N 373510. Also, for CALIFORNIA emissions, manual transaxle, replace A.I.R. management valve with PN 17082701. [273] Level road surge, tip-in hesitation, lack of low speed performance - for automatic transaxles only. (Requires EGR valve P/N 17068212). FOR FEDERAL - USE 01226055. FOR CALIFORNIA - USE 01226057. [274] Stall in coast down with clutch disengaged and A/C on, weak drive away after cold start , requires EGR TVS P/N 373510. Also, for CALIFORNIA emissions, manual transaxle, replace A.I.R. management valve with PN 17082701. [275] Idle shake, detonation (G043). FOR 2.5L EFI, AUTOMATIC TRANSAXLE, AND FIRST DESIGN (3-BOARD) ECM. THE SECOND DESIGN (2-BOARD) ECM HAS THE SPARK REVISION ALREADY INCORPORATED IN ITS PROM. [276] Chuggle/surge at 40-45 MPH, tip-in hesitation/sag, spark knock, requires EGR valve (G032). FOR CHUGGLE AT 40-45 CONDITION, USE PROM ONLY. FOR TIP-IN HESITATION ONLY, USE EGR VALVE ONLY - P/N 17078431. FOR COLD DRIVEABILITY HESITATION, USE BOTH PROM AND EGR. [277] Chuggle and surge at 35-55 MPH, requires EGR kit. REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [278] CODE 42, spark knock, cold startability, plug fouling (G040). REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [279] Chuggle and surge at 35-55 MPH, requires EGR kit (G040). REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [280] Cold hesitation/sag, warm surge (G082). RETROFIT PROM SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OF DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [281] TCC chuggle or surge (G043). WHEN INSTALLING PROM IN A CANADIAN 1985 NB, A CODE 13 WILL OCCUR AS THE VEHICLE WAS NOT EQUIPPED WITH AN O2 SENSOR. TO ELIMINATE THE CODE 13, NEED TO INSTALL O2 SENSOR # 8990741 AND CONNECT TO THE EXISTING PURPLE WIRE AND CONNECTOR IN THE [282] Surge or chuggle at 52-60 MPH (G071). RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROM. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE. [283] Surge or chuggle at 52-60 MPH (G071). RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [284] Chuggle, hesitation, tip-in spark knock. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [285] Chuggle, hesitation, tip-in spark knock. RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROMS. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [286] FOR USE WITH P215/65 TIRES - USE 01228290 (SCAN I.D. = 8290). FOR USE WITH P235/60, P245/50 TIRES - USE 01228291 (SCAN I.D. = 8291). [287] FOR USE WITH P215/65 TIRES - USE 01228292 (SCAN I.D. = 8292). FOR USE WITH P235/60, P245/50 TIRES - USE 01228293 (SCAN I.D. = 8293). [288] FALSE CODES 33, 34, 43, rough idle, chuggle, hesitation (G006,G007). USED WITH VIN #119016 OR LATER ALUMINUM HEAD CORVETTES AND ALL CONVERTIBLE MODELS WITH AUTOMATIC TRANSMISSION, 2.59 (GM1) AXLE ONLY. [289] FALSE CODES 33, 34, 43, rough idle, chuggle, hesitation (G006,G007). USED FOR VIN #119016 OR LATER ALUMINUM HAED CORVETTES AND ALL CONVERTIBLE MODELS WITH AUTOMATIC TRANSMISSION, 2.73 (GU2)/3.07 (G44) AXLE ONLY. Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Page 4977 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 434 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 5043 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 1716 For vehicles repaired under warranty use: Description Labor Op. Heater, Engine Block - Replace R4600 Use applicable labor time guide for labor hours. Page 6760 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7687 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Oil Pressure Gauge - Incorrect or Erratic Readings Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Incorrect or Erratic Readings Number: 93-57-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268304 ASE No.: A1, A8 Subject: INCORRECT OR ERRATIC OIL PRESSURE READINGS Model and Year: 1990-93 ALL LIGHT DUTY TRUCKS Owners of some 1990 through 1993 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. Service Procedure: Check for normal causes of high oil pressure gauge readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure below. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. connect the negative battery cable. Parts Information: Page 5409 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 8373 Front Park And Marker Lamps Page 151 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 8533 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Oil Pressure Gauge - Incorrect or Erratic Readings Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Incorrect or Erratic Readings Number: 93-57-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268304 ASE No.: A1, A8 Subject: INCORRECT OR ERRATIC OIL PRESSURE READINGS Model and Year: 1990-93 ALL LIGHT DUTY TRUCKS Owners of some 1990 through 1993 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. Service Procedure: Check for normal causes of high oil pressure gauge readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure below. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. connect the negative battery cable. Parts Information: Page 5203 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Specifications Backing Plate: Specifications Backing Plate Retaining Bolts.............................................................................................................. ........................................................ 47 Nm (35 ft lb) Page 8701 Note: Labor Operation is coded to base vehicle coverage in the warranty system. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 7279 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7198 Clutch Switch: Locations Cruise Control Clutch Switch Brake Pedal Switches. On the Clutch Pedal Support bracket. Specifications Flywheel: Specifications Flywheel Bolts 75 ft.lb Flywheel Housing Bolts 32 ft.lb Page 4745 Brake Caliper: Testing and Inspection Should it become necessary to remove the caliper for installation of new parts, clean all parts in denatured alcohol or brake parts cleaner, wipe dry using lint-free cloths. Using compressed air, blow out drilled passages and bores. Check dust boots for punctures or tears. If punctures or tears are evident, new boots should be installed upon reassembly. Inspect piston bores in both housings for scoring or pitting. Bores that show light scratches or corrosion can usually be cleaned with crocus cloth. However, bores that have deep scratches or scoring may be honed, provided the diameter of the bore is not increased more than 0.05 mm (0.002 inch). If the bore does not clean up within this specification, a new caliper housing should be installed (black stains on the bore walls are caused by piston seals and will do no harm). When using a hone, be sure to install the hone baffle before honing bore. The baffle is used to protect the hone stones from damage. Use extreme care in cleaning the caliper after honing. Remove all dust and grit by flushing the caliper with denatured alcohol or brake parts cleaner. Wipe dry with clean lint-free cloth and then clean a second time in the same manner. Page 4975 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 6905 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Page 5664 Steering Gear: Service and Repair Saginaw Integral Power Steering Gear System Bleeding Four factors affect operation of the steering system: fluid level and condition, drive belt tension, pump pressure and steering gear adjustment. These should always be checked before any major service operations are performed. Conditions such as, hard or loose steering, road shock or vibrations are not always due to steering gear or pump, but are often related instead to such factors as low tire pressure and front end alignment. These factors should be checked and corrected before any adjustment of the steering gear is made. If fluid level is low, add power steering fluid to proper level on dipstick and replace filler cap. 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine Off. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. Flushing Power Steering System Four factors affect operation of the steering system: fluid level and condition, drive belt tension, pump pressure and steering gear adjustment. These should always be checked before any major service operations are performed. Conditions such as, hard or loose steering, road shock or vibrations are not always due to steering gear or pump, but are often related instead to such factors as low tire pressure and front end alignment. These factors should be checked and corrected before any adjustment of the steering gear is made. If fluid level is low, add power steering fluid to proper level on dipstick and replace filler cap. 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return hose at pump inlet connector and plug connector port on pump. Position hose in large container. 3. While an assistant is filling reservoir with new power steering fluid, run engine at idle. turn steering wheel from stop to stop. Do not contact wheel stops or hold wheel in a corner as fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 4. Install all pipes and hoses. Fill system with new power steering fluid and bleed system as outlined under SYSTEM BLEEDING. 5. Operate engine for 15 minutes. 6. Remove pump return hose at pump inlet and plug connection on pump. While refilling reservoir, check draining fluid for contamination. If foreign material is still evident, replace all hoses, disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. Removal/Installation 1. On models equipped with power steering, disconnect pressure and return hoses from steering gear housing, then plug hose ends and gear housing ports to prevent entry of dirt. 2. On all models, disconnect battery ground cable and remove coupling shield if so equipped. 3. Remove retaining nuts, lock washers and bolts at steering coupling to steering shaft flange. 4. Remove pitman arm nut and washer from pitman shaft and mark relation of arm position to shaft, then remove pitman arm using a puller. 5. On turbocharged models, raise and support vehicle. 6. Remove charge air cooler radiator. 7. Lower vehicle, then remove intermediate shaft assembly at steering gear. 8. Remove attaching bolt and nut to pot joint coupling. Ensure alignment marks line up. 9. On all models, remove screws securing steering gear to frame and remove gear from vehicle. 10. Reverse procedure to install. Disassembly If broken components or foreign materials are found during disassembly of the gear, the hydraulic system should be inspected, cleaned and flushed before service is complete. The ball nut and control rings are not generally replaced unless cut or damaged. If replacing, inspect all mating parts for burrs, cracks, scratches or damage. Replace or repair as needed. Page 4664 Brake Rotor/Disc: Specifications Front Nominal Thickness 1.03 in Minimum Thickness 0.98 in Thickness Variation (Parallelism) 0.0005 in Run Out (TIR) 0.004 in Finish --- Page 4688 Brake Drum: Testing and Inspection VISUAL INSPECTION Inspect the drum for cracks. If any large, through-the-drum cracks are located the drum must be replaced. NOTE: Cracks in drums are often difficult to locate. To quickly determine if a drum is cracked lightly drop the drum (from a height of 4-5 inches) onto a flat hard surface. A cracked drum will make a dull thud sound while a good drum will make a ringing sound. Inspect for signs of overheating. An overheated drum will often be discolored (blue/gold), warped, or heat checked. Heat checks are small cracks in the drum friction surface. Heat checks can be removed by resurfacing. NOTE: The cause of the overheating should be determined prior to replacing the shoes/linings or drums. Inspect for scoring. Any grooves or scores in excess of 0.008 inches should be resurfaced. SPECIFICATIONS - See: Specifications MAXIMUM DIAMETER Purpose The thickness of the drum friction surface is directly proportional to the drums ability to absorb and release heat during braking. As the drum becomes thinner due to normal wear and resurfacing it looses its ability to absorb and release heat and is more prone to brake fade, distortion, and cracking. As the drum wears the inside diameter of the drum increases. The amount of drum thickness lost to wear is equal to 1/2 the increase in diameter. There are two specifications related to drum thickness. Discard Diameter - This is the maximum diameter at which it becomes unsafe to operate. A drum which has reached this thickness should not be machined and should be discarded. Maximum Refinish - This is the maximum diameter to which a drum may be machined or resurfaced to. This diameter is smaller (thicker) than the Discard diameter because it assumes the drum will need to have a sufficient thickness left, after machining, to allow for further wear from a new set of shoes/linings. Which One Should Be Used? If you install a new pair of shoes with the drum diameter at or less than the "Maximum Refinish" specification the drums should have a sufficient thickness to last the normal life of the new shoes/linings. The "Discard Diameter" should be used to determine if a drum needs to be replaced at the present time of inspection. If you install a new pair of shoes with the drums machined at or near "Discard Diameter", within a short time the drums will be too thin Page 6607 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 6771 Trailer Wiring Page 8224 Hazard Flashers With Digital Cluster Pressure Values Valve Spring: Specifications Intake Exhaust Closed 76-84 lbf at 1.70 in 76-84 lbf at 1.70 in open 194-206 lbf at 1.25 in 194-206 lbf at 1.25 in Page 7102 Number: 92-33-10 Section: 10 Date: NOV. 1991 Corporate Bulletin No.: 131060 ASE No.: B2 Subject: INDUSTRIAL FALLOUT/RAIL DUST DAMAGE TO BASE COAT/CLEAR COAT Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS Application: 1992 (and previous) models with Base Coat/Clear Coat Paint The following information regards the use of finesse type repairs to environmental (industrial fallout) and rail dust damage of base coat/clear coat paint finishes. Since the severity of the condition varies from area to area, PROPER DIAGNOSIS of the damage extent is CRITICAL TO THE SUCCESS OF REPAIRS. Diagnosis should be performed under high intensity fluorescent lighting, on horizontal surfaces (hood, roof, decklid) after they have been properly cleaned. INDUSTRIAL FALLOUT (ACID RAIN) There are three basic types of acid rain damage: Surface level contamination, - may be repaired by simply washing the vehicle, cleaning the surface with a wax and grease remover, neutralizing acidic residue and finesse polishing. - Clearcoat etching, - slight etching still noticeable after the above washing and finesse polishing procedure. - Basecoat etching, - severe etching beyond the clearcoat into the basecoat. PROCEDURES FOR SURFACE LEVEL CONTAMINATION REPAIRS 1. Wash the vehicle with standard car detergent and water and dry thoroughly. 2. Clean the affected area with a wax and grease remover. 3. Neutralize any left over acidic residue by cleaning the damaged areas with a mixture of baking soda and water (one tablespoon per quart of water), rinse THOROUGHLY and dry the panels completely. 4. Apply a finesse type polish with a foam pad. CLEAN AND INSPECT THE SURFACE A. If the damage has been repaired, remove any swirl marks with a dual action orbital polisher and foam pad. B. If some damage remains, proceed to step 5. SLIGHT CLEARCOAT DAMAGE - WET SANDING, FINESSE POLISHING 5. Select a small test area on a damaged panel. 6. Wet sand the damaged area with an American Grade ultra fine sandpaper of 1,500 to 2,000 grit and a rubber sponge sanding block. During the wet sand process; a. Use ample amounts of water b. Go slow to prevent removing too much clearcoat. Note: Be sure to use American Sandpaper. European Sandpaper has a "P" before the grit number and European grits do not align with American grits the majority of the time. 7. Remove the excess water with a rubber squeegee and inspect the area. A. If this has repaired the damage, continue the sanding procedure on the entire panel, apply a finesse type polish with a foam pad and remove any swirl marks with a dual action orbital polisher and foam pad. B. If (during the repair) it is suspected or observed that; - etching has penetrated into the base coat OR - too much clearcoat has been removed during sanding OR - base color is transferred to pad during polishing, The AFFECTED AREAS MAY REQUIRE RECLEARCOATING/COLORCOATING OR REFINISHING. Page 1327 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Specifications Air Duct: Specifications Plenum Side Vent Mounting Screw ........................................................................................................................................................... 2 Nm (18 in. lb.) Page 5425 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 7201 Symbol Identification Locations Vehicle Speed Sensor/Transducer - Cruise Control: Locations Electronic Control Module (ECM) & Vehicle Speed Sensor Buffer (DRAC) Behind RH Side Of I/P Page 6747 Trailer Adapter Kit: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 4496 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 5012 Disclaimer Page 12 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 3991 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 5918 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Upper Ball Joint: Service and Repair Upper Control Arms And Components Disconnecting The Upper Ball Joint Page 5191 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 293 Rear Of Instrument Cluster. On Brake Pedal Support Page 505 Door Switch: Locations Door Jamb Switch, LH Front In LH A-Pillar Glass/Body - Windshield Wiper Performance Windshield: All Technical Service Bulletins Glass/Body - Windshield Wiper Performance INFORMATION Bulletin No.: 06-08-43-003C Date: February 21, 2011 Subject: Windshield Wiper Performance, Cleaning Instructions and Maintenance Models: 2012 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2010 and Prior Isuzu Medium Duty Trucks 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2011 and 2012 model year. Please discard Corporate Bulletin Number 06-08-43-003B (Section 08 - Body and Accessories). Wiper Concerns Most concerns about windshield wiper performance are the result of dirty wiper blades, damaged wiper blades, or worn out blades that are continuing to be used beyond their useful life. Depending on environmental conditions, wiper blades can have dramatic differences in lifespan. Here are some tips and guidelines to maximize wiper performance to avoid damage to the blades, and to avoid unnecessary replacements. Many wiper blades are being replaced under warranty with reviews showing there is nothing wrong with the returned blades other than a build-up of dirt. Additionally, advise the customer to review the information in their Owner Manual. Inspection and Cleaning Scheduled Maintenance - Inspect your wipers rubber blades every 4-6 months or 12,000 km (7,500 mi) for wear, cracking or contamination. - Clean the windshield and the rubber wiper blades (using the procedure below) if the blades are not clearing the glass satisfactorily. If this does not correct the problem, then replace the rubber elements. Cleaning Procedure Important Avoid getting windshield washer fluid on your hands. Wear rubber gloves or avoid direct contact with washer fluid. Important Do not use gasoline, kerosene, or petroleum based products to clean wiper blades. - Clean the rubber blades using a lint free cloth or paper towel soaked with windshield washer fluid or a mild detergent. You should see significant amounts of dirt being removed on the cloth. - Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road grime, sap and a buildup of car wash/wax treatments may additionally cause wiper streaking. Tip For a larger scale buildup on the windshield, use a non-abrasive cleaner such as Bon-Ami* (www.faultless.com) cleanser with a wet sponge, being sure to use plenty of water to avoid scratching the glass. Flush the surface and body panels completely. Tip For day-to-day exterior glass cleaning and to maintain a streak free appearance, suggest Vehicle Care Glass Cleaner, P/N 88862560 (in Canada, 992727). This product is an easy to use foaming cleaner that quickly removes dirt and grime from glass surfaces. Tip Interior glass should be cleaned with plain, clean water to eliminate any film or haze on the window and help prevent fogging, a major customer dissatisfier. Refer to Corporate Bulletin Number 03-00-89-006D for more information. The New Vehicle Pre-Delivery Inspection form also recommends using plain water to clean interior glass. *"We believe this material to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or any such items which may be available from other sources. Page 299 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 5666 4. Remove nut, bolt, side cover and gasket, then turn adjuster screw right until side cover separates from pitman shaft. 5. Remove piston shaft, then turn stub shaft left until pitman shaft teeth and rack piston disengage. 6. Remove retaining ring, washers and seals, then remove bearing with bearing removal tool No. J-6278 or equivalent if necessary. Fig. 3. 7. Remove rack piston and balls as follows: a. Insert ball retainer tool J-21552 or equivalent into rack piston bore with pilot seated into end of worm, refer to Fig. 2. b. Hold tool against worm and turn stub shaft to left. Rack piston will be forced onto the tool. c. Hold tool and pull rack piston toward handle until it is against flange. This will prevent end circuit balls from falling out. Fig. 4 Adjuster plug removal Fig. 5 Needle bearing removal Fig. 6 Worm shaft & valve body removal Initial Inspection and Diagnostic Overview Torque Converter Clutch: Initial Inspection and Diagnostic Overview Torque Converter Clutch (TCC) Circuit Check Page 6354 5. Anytime the A/C system has been "opened" it should be properly evacuated before recharging. Page 6432 FOR ALL VEHICLES EXCEPT GEO, see the "Compressor Replacement Chart" at the end of this section. Compressor replacement requirements ARE NOT LISTED in the platform details (except for application details), except as noted below for Y car and P and Medium Duty truck. Compressor Replacement Chart Important: It is important to check the date code on the compressor. Any vehicle may have had a compressor replaced either during or after the warranty period. The date code will determine whether or not the compressor must be replaced. Compressor Availability A new compressor for use with R-134a systems will be shipped with the correct amount of PAG oil installed (see "IMPORTANT" below). Do not add any additional oil in Step 5 of the retrofit procedure if a compressor is to be replaced with a new R-134a compressor at the same time the initial retrofit is Page 8315 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 6242 The chart shown will help to properly identify the seals. Use the chart by placing the seal over the pictured seal to identity inside and outside diameters and thickness. Because these seals are very similar in size, specifications are also listed in the chart. Important: If seals are damaged upon installation, obtain new seal kit. Seals will be available separately at a later date. Locations Air Intake Ducts 4.3W S/T Utility Specifications Bell Housing: Specifications Clutch Housing to Engine Bolts ........................................................................................................... ................................................................... 55 ft. lbs. Page 6104 Blower Motor: Service and Repair Evaporator and Blower Assembly Replacement Evaporator And Blower Case Replacement REMOVE OR DISCONNECT 1. Discharge and recover refrigerant from the system. 2. Electrical connectors, as necessary. 3. Compressor hose assembly (3) from accumulator (6). 4. Evaporator tube (5) from evaporator (10). - Cap or plug open lines. 5. Screws (29) and nuts (37). 6. Blower case (30). 7. Gasket (24). INSTALL OR CONNECT 1. Gasket (24). 2. Blower case (30). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 3. Screws (29) and nuts (37). 4. Evaporator tube (5) to evaporator (10). 5. Compressor hose assembly (3) to accumulator (6). Tighten - Evaporator tube connection to 41 Nm (30 ft. lb.). Service and Repair Torsion Bar: Service and Repair Fig. 18 Torsion Bar Replacement. 4 X 4 Models Refer to Fig. 18 for torsion bar replacement procedure on 4 x 4 vehicles. Page 6377 f. TO INSURE AN ACCURATE CHARGE AMOUNT, IT IS IMPORTANT TO CLEAR THE ACR4 OF ANY REMAINING REFRIGERANT. Close the high side coupler valve and remove the high side hose from the vehicle. Then, open both the high and low side valves on the ACR4. After the pressures on both gages are at low side pressure, close the low side coupler valve. See Step G below, then remove the low side hose from the vehicle. Shut off the engine. Install the service port caps on the new fittings. These serve as a seal and can prevent system leaks. g. In the unlikely event that the low side fitting leaks when the coupler is removed, use the following procedure: 1. Immediately reinstall the coupler on the fitting. 2. Find the valve core remover J 34611-A. 3. Remove the coupler. 4. Use the double-ended valve core remover to turn the valve core pin counter-clockwise until the leak stops. 5. Install the cap. If the leak was substantial or continued for an extended period of time, it is highly recommended to evacuate and recharge the system to insure proper performance. If there is any question, the system can be rechecked by repeating Step F. h. Leak test any new port fittings, adapters, or valves that were installed, and any joints that were opened or repaired during the retrofit process, using tool J 39400. 6. Install the Retrofit Label The retrofit label (P/N 21030857, roll of 250) has been developed following SAF specifications to insure a smooth transition from R-12 to R-134a, and to insure a professional approach to the retrofit and a quality repair. Following the instructions in this bulletin will insure that the retrofit meets the SAE standards. Fill in the new label using a typewriter or a ball-point pen (see Figure 6). Select a location for the label that will be easily visible. Some suggested areas are the radiator support panel, an area near the existing R-12 charge label, or a flat surface near the high or low side service ports. The area selected should be a clean, underhood, painted sheet metal surface, and should be degreased and wiped down with a non-petroleum based cleaner. Do not install the label on a rubber surface. Apply the label, then apply the clear overlay to the label. Do not remove, cover, or render unreadable the existing R-12 charge label. DO cover the R-12 refrigerant charge amount on the existing label with an indelible, preferably black, marker. Platform Details Page 54 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 6045 A/C And Heater Wiring Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Locations Engine Wiring, LH Side Page 6294 6. Remove blower motor switch. (Figure 2) 7. Remove the 2 control base plate mounting screws. (Figure 2) 8. Remove the control baseplate. 9. Remove the 4 housing to bezel mounting screws. (Figure 3) 10. Discard the broken housing. 11. Apply a small amount of GM silicone grease, P/N 12345579, or its equivalent to areas of the new housing where the mode and temperature levers protrude through the housing slots. (Figure 3) NOTE: Do not use petroleum based lubricants. Petroleum based lubricant causes the housing material to become brittle and generate a repeat failure. 12. Reassemble using the reverse procedure. Use care when assembling the base plate to the housing and bezel. The mode control lever must be Locations Fog Lamp Switch And Relay Wiring Page 2830 Knock Sensor: Description and Operation Electronic Spark Control Circuit Knock Sensor (KS) Sensor PURPOSE Varying octane levels in today's gasoline can cause detonation (also known as spark knock) in an engine. The Knock Sensor (KS) system has various knock sensors that are used on all engines except the 2.5L. The KS system reduces spark knock (detonation) in the engine. This allows the engine to have a maximum spark advance for improved driveablity and fuel economy. CONSTRUCTION This KS system has three main components: - KS Module. - Knock sensor - ECM OPERATION The knock sensor detects abnormal vibration (spark knocking) in the engine. The knock sensor is mounted in the engine block near the cylinders. The KS module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the Ignition Control (IC) to reduce spark knocking. The KS module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the knock sensor. This allows the ECM to maintain maximum timing advance under various engine load conditions. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards IC to reduce spark knock. Page 7369 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 8283 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7097 Hood ornaments Wheel opening moldings Side view mirrors Grille and headlamp bezels Door edge guards Bumper filler panel, Frt./Rr. Front side marker lamps *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary G VANS Wiper arms Cowl vent grille Grille and headlamp bezels Front bumper filler panel Antenna Side view mirrors Side marker lamps Tail lamps Door edge guards Wheel opening moldings *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary Swing out windows/seals WARRANTY INFORMATION For vehicles repaired under warranty. and for customer satisfaction. use: Labor Op (Labor Operations include mix time) A6100 Refinish the entire exterior body surface ABOVE THE BODY SIDE MOLDING AND INSERT COLOR on two tone vehicles if equipped. A6101 Refinish the entire exterior body surface INSERT COLOR only. A61O2 Refinish the PICKUP BOX LOAD FLOOR AND INNER FENDERS when applicable. A61O3 On units with an insert color, included is the entire exterior body surface ABOVE THE BREAKLINE. (If the insert color and the entire body surface above the break-line requires refinishing, use A6100). Page 319 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Locations Engine Wiring, LH Side Page 8356 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 6231 Installing Clutch Plate & Hub Assembly 4. Remove the J 33013-B remover-installer center screw and reverse the body direction on the center screw as shown in the illustration. 5. Install the clutch plate and hub installer J 33013-B with bearing as shown in the illustration. The body of the J 33013-B installer should be backed off sufficiently to allow the center screw to be threaded onto the end of the compressor shaft. 6. Hold the center screw with a wrench. Tighten the hex portion of the installer J 33013-B body to press the hub onto the shaft. Tighten -the body several turns, remove the installer-and check to see that the shaft key is-still in place in the keyway before installing the clutch plate and hub assembly to its final position. The air gap between frictional surfaces of the clutch plate and clutch rotor should be 0.50-0.076 mm (0.20-0.030"). - If the center screw is threaded fully onto the end of the compressor shaft, or if the body of the installer is held and the center screw is rotated, the key will assume the position and will break the clutch hub. 7. Remove installer J 33013-B, check for proper positioning of the shaft key (even or slightly above the clutch hub). Install the shaft nut. Hold the clutch plate and hub assembly with clutch hub holding tool J 33027-A and using shaft nut socket J 33022, tighten the nut against the crankshaft shoulder to 16.5 N.m (12 lbs.ft.) torque, using a 17.5 N.m (12.5 lbs.ft.) torque wrench. 8. Spin the pulley rotor by hand to see that the rotor is not rubbing the clutch drive plate. Page 1204 thread locking compound, such as Loctite(R) 242, should be used on each bolt of the saddle clamp to prevent the threads from loosening. Some vehicles produced during the second half of the 1993 model year will already have a factory installed HPCOS. Check the back of the compressor for this switch. If present, the above switch will not have to be added. 5. Evacuate the System, and Recharge with PAG or V5 Retrofit Oil and R-134a Newly designed low profile quick connect couplers for the ACR4, J 39500-20A and J 39500-24A, have been released. These should be installed before proceeding with the evacuation. See Step 3, and Figure 3. a. Connect the R-134a cart (ACR4) to the system. Open the coupler valves on the hoses so that the pressures can be read on the gauges. On the cart, open the HIGH SIDE VALVE ONLY. DO NOT OPEN THE LOW SIDE VALVE! Program the cart for a 15 minute evacuation. Important: If the vehicle has been at outside temperatures of less than 50° F (10° C), or at high altitudes (above 3000 ft), use a 30 minute evacuation to insure complete removal of the R-12. If the vacuum pump will not start and a "H-P" reading is indicated on the ACR4 display, loosen the fitting at the high side line connection to the ACR4 to relieve pressure in the line. Tighten the fitting after pressure has been relieved. DO NOT USE THE RECOVERY MODE TO RELIEVE LINE PRESSURE. b. Start the evacuation. For a proper evacuation, the cart must pull down to 28-29 in. Hg. at sea level (reduce by 1 in. for each 1000 ft above sea level). Check the low side gauge for proper vacuum level, to make sure the new fittings are operating properly. While the evacuation is being done, the Retrofit label can be filled out and installed (see Step 6). Important: If the compressor was replaced at the same time as this retrofit, and the new compressor was shipped with the correct amount of PAG oil already in it, DO NOT add any additional oil to the system! Go to Step D. If an "oil-less" compressor was installed, add oil in Step C. A new retrofit oil for use with V5 compressor vehicles has been released. This oil will be used ONLY for retrofitted vehicles in which the original V5 compressor is retained. IT WILL NOT BE USED IF A COMPRESSOR IS REPLACED AT THE TIME OF THE RETROFIT. Failure to use this oil may significantly shorten the useful life of the compressor. Important: If the V5 Retrofit oil is not available from GMSPO, the compressor MUST BE REPLACED! To summarize the correct retrofit oil usage: ^ Compressor replaced during retrofit - NO OIL ADDED if new compressor shipped with oil - 8 oz. of PAG oil (9 oz of PAG oil with V5 compressor) added if compressor shipped without oil ("oil-less" design) Page 8300 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 3422 SERVICE PARTS INFORMATION WARRANTY INFORMATION Page 8046 Page 6159 4. Hold the J 33020 Puller in place and tighten the puller screw against the Puller Guide to remove the pulley rotor and bearing assembly (Fig. 17). 5. To prevent damage to the pulley rotor during bearing removal, the rotor hub must be properly supported. 5. To prevent damage to the pulley rotor during bearing removal, the rotor hub must be properly supported. Remove the forcing screw from J 33020 Puller and with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks as shown in Figure 18. 6. Drive the bearing out of the rotor hub with Rotor Bearing Remover J 9398-A and J 29886 Universal Handle (Fig. 18). It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will be necessary to file away the old stake metal (Fig. 21) for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Door Armrest Replacement Power Window Motor: Service and Repair Door Armrest Replacement Front Door Trim Panel REMOVE OR DISCONNECT 1. Screws securing the armrest to the door trim. 2. Armrest from the door trim. ^ Slide the armrest towards the rear of the door, and then, lift the armrest from the door. INSTALL OR CONNECT 1. Armrest to the door trim. ^ Place the armrest retaining clips in the slots on the door panel. ^ Slide the armrest toward the front of the door unit the holes in the armrest align with the holes in the door trim. 2. Screws securing the armrest to the door trim. Fuel - Reformulated/Oxygenated Gasolines Fuel: All Technical Service Bulletins Fuel - Reformulated/Oxygenated Gasolines FILE IN SECTION: 0 - General Information BULLETIN NO.: 57-01-02 DATE: June, 1995 SUBJECT: Reformulated Gasoline (RFG), Oxygenated Gasoline and California Phase 2 RFG MODELS: 1995 and Prior Passenger Cars and Trucks General Motors customers will be potentially exposed to a variety of different fuel types. Besides the conventional gasoline available, new types such as Reformulated Gasoline (RFG), oxygenated gasoline, and starting in 1996, California Phase 2 RFG. Reformulated Gasoline (RFG) is blended to burn more cleanly and not to evaporate as readily. RFG must contain a minimum of 2 percent oxygen, which is usually achieved with ethanol or EPA-approved ethers such as methyl tertiary-butyl ether (MTBE). This type of fuel is required by the Clean Air Act in the nine worst ozone non-attainment areas of the country, and may also be required in other areas designated ozone non-attainment, at the option of the states. RFG is intended to produce approximately 15 percent less pollution than conventional gasoline. Using RFG should reduce the total health risk to the public by reducing exposure to ozone and air toxins. General Motors supports the use of RFG as a cost effective means of providing air quality benefits. Oxygenated gasolines are prevalent in the wintertime for Carbon Monoxide (CO) non-attainment areas. These fuels contain oxygen components similar to RFG. Approximately 50 percent of the fuel sold in the U.S. in the wintertime contains an oxygenate component. Vehicle fuel economy may be slightly reduced, if at all, by the use of gasoline containing oxygenates. Fuel economy is most affected by engine and vehicle type, driving habits, weather conditions, and vehicle maintenance. Properly blended RFG, oxygenated gasoline, and California Phase 2 RFG will have no adverse effect on vehicle performance or to the durability of engine and fuel system components. In fact, the General Motors Owner's Manual fuel statements have consistently permitted the use of properly blended fuels containing up to 10 percent ethanol (since 1980) and up to 15 percent methyl tertiary-butyl ether (MTBE) for current and all past model year vehicles. These statements continue to be valid. The use of oxygenate-containing fuels will not invalidate the GM vehicle warranty. Page 8216 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires PROM - Powertrain Control Module Reprogramming PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Powertrain Control Module Reprogramming File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-04-053 Date: November, 1999 INFORMATION Subject: Powertrain Control Module (PCM) Reprogramming (Do Not Reprogram Using the Same Download Files as Those Already Present in The Control Module) Models: 1990-2000 Passenger Cars and Trucks with Reprogrammable PCM It is strongly recommended to NOT reinstall the same software and/or calibration download file(s) into the powertrain control module as those that are already present in the PCM. There is no technical reason that the download files inside the PCM would ever become corrupted after the control module had previously been successfully programmed. A P0601 (Control Module Read Only Memory) Diagnostic Trouble Code would set in memory and the MIL would be illuminated if the controller memory became corrupted. The Techline Information System 2000 (TIS 2000) PC, combined with vehicle information gained through the Tech 2, can determine when an attempt to reprogram a PCM using the same download files (as those already in the control module) is being requested. If this is attempted, the TIS 2000 PC currently displays the following message: Notice: THE CALIBRATION SELECTED IS THE CURRENT CALIBRATION IN THE CONTROL MODULE. PROGRAMMING WITH THE SAME DOWNLOAD FILES IS NOT AN EFFECTIVE REPAIR. SELECT ( YES ) TO CONTINUE PROGRAMMING THE CONTROL MODULE,OR ( NO ) TO CANCEL. Effective in the first quarter of 2000, the TIS 2000 PC will indicate: Important: THE CALIBRATION SELECTED IS ALREADY THE CURRENT CALIBRATION IN THE CONTROL MODULE. REPROGRAMMING WITH THE SAME DOWNLOAD FILE IS NOT ALLOWED. Certain learned values, such as: (but not limited to) ^ fuel trim (previously known as block learn memory), ^ IAC learned position in various park/neutral and air conditioning on/off combinations, ^ certain OBDII diagnostic thresholds, ^ automatic transmission shift adapts will revert back to their unlearned starting point values after a reprogramming event occurs. It is feasible that the engine or transmission might temporarily operate differently after a reprogramming event, until these values are re-learned. Relearning occurs while operating the vehicle through normal driving routines. If the same download files are simply reinstalled, any changes noticed in engine operation will likely disappear in a short amount of time and/or driving distance. Reprogramming the control module with the same download files that already exist in the module will only accomplish a warranty claim for a non-effective repair, and a likely comeback. Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: All Technical Service Bulletins Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 8453 LH I/P Harness Wiring Locations Cruise Control Servo: Locations Cruise Control Components. LH Side Of Engine Compartment Page 2176 Coolant Level Indicator Lamp: Service and Repair This lamp will be illuminated when engine coolant level in the radiator drops below a pre-determined level. To turn lamp "OFF," check cooling system, then add coolant to bring system to proper level. Page 414 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 6614 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7169 Brake Vacuum Release Valve: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 4011 Shift Linkage: Specifications 4L60 & 4L60-E Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Manual Shaft To Inside Detent Lever .................................................................................................. .............................................................................. 23 Page 5510 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Page 6870 11. Install cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time B1717 Replace Use Published Labor Hood Hinge Operation Time Page 3886 Page 2663 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Body - TPO Fascia Cleaning Prior to Painting Front Bumper Cover / Fascia: Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer CPI - Fuel Leak May Cause Driveability Problems Fuel Supply Line: All Technical Service Bulletins CPI - Fuel Leak May Cause Driveability Problems Number: 93-99-6C Section: 6C Date: FEB. 1993 Corporate Bulletin No.: 266306 ASE No.: A1, A8 Subject: CENTER PORT FUEL INJECTION (CPI) LINE CLIPS INFORMATION Model and Year: 1992-93 S/T AND M/L TRUCKS WITH 4.3L ENGINE (RPO 135) Improper installation of the fuel line clips which hold the fuel inlet and outlet tubes to the Central Port Fuel Injection (CPI) unit may result in an internal CPI fuel leak. A fuel leak may cause driveability problems or in extreme cases, hydrolock. Proper Removal and Installation of Fuel Line Clips Removal: Using needle nose pliers, firmly grasp the fuel fitting clip as shown in Figure 1 and pull the clip straight back from the fuel meter body. It may be necessary to lift the opposite side of the clip with a screwdriver. Discard the clip. Installation: Always use a new clip and O-rings (P/N 17112702). Using your fingers as shown in Figure 2, slide the clip over the fuel meter body making sure that the clip properly engages the slots in the fuel inlet and outlet tubes and that the clip is properly positioned over the fuel meter body on both the top and bottom sides. The clip will be properly positioned when the flanges on the fuel meter body protrude from the clip and the clip snaps in place. IMPORTANT: Do not install the clip from the bottom-up position, the clip will not properly retain the fuel lines. Install the clip from the top-down position as shown in Figure 2. Secondly, it is important to note that the fuel lines MUST be in the correct inlet/outlet openings (The lines will fit either opening). Lastly, the fuel lines MUST be correctly seated into the TBI body to allow for proper installation of the clips. Parts Information: Part Number - 17112702 Description - Seal Kit Parts are currently available from GMSPO. Page 78 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Description and Operation Fuel Pump Signal: Description and Operation PURPOSE The fuel pump voltage signal is used by the control module as a reference to determine fuel system electrical loading and circuit integrity. OPERATION The status of the fuel pump CKT 120 is monitored by the control module and is used to compensate fuel delivery based on system voltage. This signal is also used to store a DTC if the fuel pump relay is defective or fuel pump voltage is while the engine is running. There should be about 12 volts on CKT 120 for at least 2 seconds after the ignition is turned "ON" or any time reference pulses are being received by the control module. With PCM/VCM systems DTC 54 (VCM is DTC P1222) will set if the voltage at control module fuel pump signal terminal is less than 2 volts for 1.5 seconds since the last reference pulse was received. This DTC is designed to detect a faulty relay, causing extended crank time, and the DTC will help the diagnosis of an engine that "Cranks But Will Not Run". With ECM systems DTC 54 will set if the voltage at control module fuel pump signal terminal is less than 2 volts for 5 seconds since the last reference pulse was received. This DTC is designed to detect a faulty relay, causing extended crank time, and the DTC will help the diagnosis of an engine that "Cranks But Will Not Run". Page 7526 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 7502 Page 6329 Expansion (Orifice) Tube The plastic expansion tube is located in the evaporator inlet pipe. Fuel System - Factors That Affect Economy/Mileage Fuel: All Technical Service Bulletins Fuel System - Factors That Affect Economy/Mileage Number: 93-96-6C Section: 6C Date: FEB. 1993 Corporate Bulletin No.: 306502 ASE No.: A1, A8 Subject: FACTORS THAT AFFECT FUEL ECONOMY Model and Year: ALL YEARS ALL MODELS BACKGROUND INFORMATION: EPA fuel economy estimates are posted on the fuel economy label of all new vehicles. The only intended use of these values is for comparison among the different vehicles. Fuel economy estimates are generated from data taken during a laboratory test using pre-production prototype vehicles under extremely controlled conditions using a professional driver, with the vehicle operating on an instrument similar to a treadmill. The comparisons of current vehicle fuel economy to the EPA fuel economy estimates is a misuse of the information and should be discouraged. The EPA GAS MILEAGE GUIDE, available at each dealership, points out that the actual mileage when driving a vehicle may differ considerably from the estimated mileage. The guide also describes how vehicles are tested under identical conditions to insure the results can be compared with confidence. The EPA GAS MILEAGE GUIDE also points out that city fuel economy estimate simulates a 7.5 mile, stop-and-go trip with an average speed of 20 mph. The trip takes 23 minutes and has 18 stops. About 18 percent of the time is spent idling, as in waiting at traffic lights or in rush hour traffic. Two kinds of engine starts are used - the cold start, which is similar to starting a car in the morning after it has been parked all night - and the hot start, similar to restarting a vehicle after it has been warmed up, driven and stopped for a short time. The test to determine the highway fuel economy estimate represents a mixture of "non-city" driving. Segments corresponding to different kinds of rural roads and interstate highways are included. The test simulates a 10 mile trip and averages 48 mph. The test is run from a hot start and has little idling time and no stops. The EPA GAS MILEAGE GUIDE explains that the actual test results are adjusted downward to arrive at the estimates used in the booklet and on the labels. City estimates are lowered by 10 percent and the highway estimate by 22 percent from the laboratory test results. The guide also points out that traveling at higher speeds lowers fuel economy and traveling at 65 mph instead of 55 mph lowers fuel economy over 15 percent. FACTORS THAT AFFECT FUEL ECONOMY: Axle Ratio Numerically lower axle ratios generally produce better highway fuel economy. The exception to this is if the engine is "working" exceptionally hard, (heavy vehicle loads pulling a trailer, small engine in a large vehicle ... ). In these cases a numerically higher axle may provide better fuel economy. Numerically higher axle ratios will also tend to provide more fuel economy in congested city traffic and stop and go conditions. Brakes Brake drag (even a minimal amount undetectable by coasting), can have a significant negative impact on fuel economy. Pull upward on the brake pedal to assure that the stoplight switch and cruise switch at the brake pedal are full and properly adjusted. A "click" sound when the pedal is pulled upward indicates that the switch was improperly adjusted. This causes the front brake pads to lightly rub the rotors, causing a fuel economy loss, without generating excessive heat or brake pad wear. Driving Habits Frequent short trips (less than 5 miles), especially in cooler ambient temperatures (less than 65 degrees), will necessitate fuel enrichment on start-ups, especially after "soaks" with the engine off for approximately a half hour or more. Frequent accelerator pedal movement while driving will reduce fuel economy because of fuel enrichment during the periods of acceleration. Under such driving conditions the torque converter clutch (TCC) also disengages, contributing to fuel economy losses. Prolonged idle periods reduce fuel economy especially in cold ambients when vehicle is allowed to "Warm up". Page 7802 Voltmeter Is Inaccurate Page 5289 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 1903 Oil Pressure Sender: Locations Engine Sensor Locations. Top Rear Of Engine Applicable to: Except 4.3L/V6-262 HP & 4.3L/V6-262 Turbo Engines Page 5530 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 4632 Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. Note: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 8. Open the bleeder valve at least 3/4 of a turn and allow the fluid to flow until no air is seen in the fluid. Tighten the bleeder valve. 9. Repeat step 7 and 8 at each wheel cylinder/caliper until all the air is purged. 10. Disconnect the bleeder tank hose from the bleeder adaptor and remove the bleeder adaptor. 11. Fill the master cylinder to the proper level and replace lid. 12. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs. in.). 13. Remove the valve pressure bleeding tools J 39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 14. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. Important DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 15. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. Important DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 16. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs. in.). 17. Remove the bleeder adaptor, if using the pressure bleed procedure (Figure 1), and fill the master cylinder to the proper level with brake fluid. 18. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. Important MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 19. Repeat the entire brake bleed procedure if necessary. Page 4456 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Distributor Operation Distributor: Description and Operation Distributor Operation EST Distributors With Separate Coil (Typical) Locations Power Window And Door Lock Body Wiring W/Outside Power Mirrors Page 6919 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot PROM - Programmable Read Only Memory: All Technical Service Bulletins M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot BULLETIN NUMBER: 92-7B-149A SECTION: 7B Manual Transmission NUMBER: 1 CORPORATE REFERENCE NUMBER: 2672O1R DATE: August 1993 SUBJECT: NEUTRAL GEAR RATTLE (REPLACE CLUTCH DISK, PROM AND PILOT BUSHING) MODELS: 1990-92 C/K AND 1990-92 S/T WITH 4.3L AND 5 SPEED MANUAL TRANSMISSION This bulletin cancels and replaces Truck Bulletin 92-7B-149 (corp. # 267201R) dated December 1992, and is being revised to add the 1992 model year S/T Trucks with 4.3L engines (RPO LB4) and to add the "Detonation and Neutral Gear Rattle Proms" section. CONDITION Some owners of 1990-92 C/K and 1990-92 S/T Trucks with 4.3L engines (RPO LB4) and 5-speed manual transmission (RPO's MG5, MY2) may comment that the transmission rattles when in neutral with their foot off the clutch pedal and the engine at idle. The customer may describe the rattle as loose bearings. CAUSE This rattle noise is created when the turning transmission gears contact against each other. The contact is created by the firing impulses of the engine which causes rapid acceleration and deceleration of the individual gears. CORRECTION This condition may be corrected by the installation of the following parts: - A revised clutch driven disc which features a live degree neutral stage. This neutral stage helps to smooth the rapid acceleration and deceleration of the individual transmission gears. - A revised PROM which raises engine idle speed to 650 RPM on C/K and 700 RPM on S/T. This increase in idle speed helps to smooth the engine firing pulses. - A clutch pilot bearing rather than a clutch pilot bushing. This bearing helps to isolate the transmission from the engine idle acceleration/deceleration. SERVICE PROCEDURE Important Incorrect engine idle can contribute to neutral gear rattle. Before installing the parts listed in this bulletin, refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 2, Driveability Symptoms "Rough, Unstable or Incorrect Idle Stalling" to verify there are no existing conditions contributing to a rough idle which may aggravate neutral gear rattle. Clutch Disc and Pilot Bearing Replacement: Refer to the appropriate year and model Service manual, Section 7C "Clutch Assembly and Pilot Bearing Replacement." Important C/K trucks require pressure plate P/N 15974649 which was first used in production mid-1991. 1990 and 1991 vehicles built prior to the following VIN breakpoints require installation of P/N 15974649 unless it has already been installed in a service repair: Ft. Wayne (Z) MZ516555 Oshawa (1) M1526826 Pontiac (E) ME51G465 PROM Replacement: Refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 3 "On-Vehicle Service, PROM". Contaminated R12 Refrigerant - Testing & Handling Refrigerant: Technical Service Bulletins Contaminated R12 Refrigerant - Testing & Handling FILE IN SECTION: 1 - HVAC BULLETIN NO.: 53-12-05 DATE: May, 1995 SUBJECT: Contaminated R12 Refrigerant Testing and Handling MODELS: 1994 and Prior Passenger Cars and Trucks with R12 A/C Systems The J 39851 "PureGuard" R12 refrigerant monitor was recently shipped to all GM dealers as an essential tool to test R12 refrigerant. Dealers are strongly urged to install this protective device on their ACR3 or other R12 recovery equipment immediately. The PureGuard is easily installed on any recovery cart (20 minutes), requires no recovery cart modifications, is fully automatic (no training required) and does not increase the time required to perform normal A/C service procedures. Proper use of this tool can: ^ Prevent damage to your R12 recovery/recycling equipment. ^ Prevent contamination of previously recovered R12 in the recovery tank. ^ Prevent loss of your recovered R12 as contaminated refrigerant will activate automatic air purge system. ^ Prevent the spread of contaminated R12 to other vehicles you service. If your dealership has multiple R12 recovery stations which are not protected, use the PureGuard to check the refrigerant in these recovery tanks for contamination at least once each week. Simply connect the PureGuard blue service hose (that would normally be connected to the vehicle low side service port) to the red or vapor side of any recovery cart tank and run the test. It is also important to check a tank containing recovered/recycled material for purity before installation on your charging equipment. Even new R12 refrigerant purchased from sources other than GM should be tested for contamination prior to use. Sources of Contaminated R12 Refrigerant Since refrigerant testing has not been a standard practice in the mobile A/C repair industry, the amount of R12 refrigerant contamination is unknown. As R12 prices rise and supplies are depleted, it is anticipated that contaminated R12 refrigerant may become more prevalent from the following as well as other sources: ^ The use of R12 refrigerant substitutes without installation of unique service fittings and proper identification labeling. ^ Improper use of R12 substitutes, such as topping off R12 systems with R134a or other refrigerants available to "do-it-yourselfers". ^ Poor quality or contaminated new or reprocessed R12 refrigerant. R12 can and should continue to be used to service vehicles built with R12 as long as it is available. Combining any refrigerant with R12 results in a refrigerant mixture which cannot be used in an A/C system. R134a is the only substitute refrigerant approved by GM and should only be used when the appropriate retrofit service bulletin procedures are explicitly followed. Use of any other substitute refrigerant requires the purchase of additional dedicated recovery, recycling (if applicable) and charging equipment to service each substitute refrigerant used. However, you should know that the Environmental Protection Agency (EPA) has listed several products as acceptable replacements for R12 mobile A/C systems under the Significant New Alternatives Policy (SNAP). Some of these products are: R134a, R401c (a DuPont refrigerant blend) and FRIGC (another refrigerant blend). It is important to understand that the SNAP program only considers the health, safety and environmental characteristics of a chemical. It does not test for A/C system cooling performance or durability. That judgment is deferred to the vehicle manufacturer. Use of any R12 refrigerant substitute without dedicated service equipment, unique fittings, labels and refrigerant testing prior to recovery, could result in contamination of the R12 supply and the loss of the R12 recycling program. What To Do When Contamination is Detected Repeat the test to verify contaminated refrigerant is present. Clear the PureGuard following the instructions listed on the face panel, then perform a second test to verify that the vehicle A/C system contains contaminated or mixed refrigerant. Contact the vehicle owner to advise that previous A/C system repairs were apparently performed with an R12 refrigerant substitute. Suggest the owner Page 7388 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 8396 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 4543 Symbol Identification Page 2564 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Specifications Extension Housing: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Case Extension To Case ..................................................................................................................... ................................................................................ 26 Page 7241 Figure 7 Figure 8 Figure 9 Figure 10 Page 8284 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 1790 - Adjust converter to center the mounting pins in the insulators. This equalizes the hanger load at the insulators (Figure 2). - Move U-bolt back to original position and tighten. 3. Settle the powertrain by shifting from DRIVE to REVERSE with automatic transmission or 1ST to REVERSE with manual transmission, at least three times with engine at idle. Then turn engine off. 4. Tighten all fasteners with the powertrain in a relaxed position (vehicle in neutral). Torque to specifications in Service Manual X-9129. Note: Be sure that the catalytic converter hanger and hanger pins are centered in the insulators, the pins should have 6.0-16.0 mm (1/4 in. - 5/8 in.) clearance as shown in Figure 2. Specifications Idle Speed: Specifications CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Auto D 550 5-40 CL [1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). Page 6759 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Interior - Itch Noise From Windshield Pillar Area Dashboard / Instrument Panel: Customer Interest Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 1461 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Page 1083 All 2006 and future model transmissions that use DEXRON(R)-VI are to be serviced ONLY with DEXRON(R)-VI fluid. DEXRON(R)-VI is an improvement over DEXRON(R)-III in the following areas: * These ATF change intervals remain the same as DEXRON(R)-III for the time being. 2006-2008 Transmission Fill and Cooler Flushing Some new applications of the 6L80 six speed transmission will require the use of the J 45096 Flushing and Flow Tester to accomplish transmission fluid fill. The clean oil reservoir of the machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI. Parts Information Disclaimer Page 3635 Torque Converter Clutch Solenoid: Locations Torque Converter Clutch Solenoid (TCC) Inside automatic transmission attached to valve body. Page 791 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 561 Door Switch: Locations RH Front Door Jamb Switch In RH A-Pillar Page 7424 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7205 Clutch Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Diagram Information and Instructions Audible Warning Device: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 3471 Throttle Position Sensor: Mechanical Specifications Throttle Position Sensor 18 in.lb Page 4736 Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. Note: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 8. Open the bleeder valve at least 3/4 of a turn and allow the fluid to flow until no air is seen in the fluid. Tighten the bleeder valve. 9. Repeat step 7 and 8 at each wheel cylinder/caliper until all the air is purged. 10. Disconnect the bleeder tank hose from the bleeder adaptor and remove the bleeder adaptor. 11. Fill the master cylinder to the proper level and replace lid. 12. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs. in.). 13. Remove the valve pressure bleeding tools J 39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 14. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. Important DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 15. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. Important DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 16. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs. in.). 17. Remove the bleeder adaptor, if using the pressure bleed procedure (Figure 1), and fill the master cylinder to the proper level with brake fluid. 18. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. Important MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 19. Repeat the entire brake bleed procedure if necessary. Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Initial Inspection and Diagnostic Overview Map Light: Initial Inspection and Diagnostic Overview 1. Check condition of RADIO Fuse. Page 7896 Cluster Display Does Not Light. Description and Operation Vacuum Pump: Description and Operation These vehicles use either a belt driven or gear driven vacuum pump to aid the engine in maintaining a proper vacuum level for the power brake system and other vacuum powered accessories. The gear driven pump is a diaphragm pump that requires no periodic maintenance. This pump is driven by a cam inside the drive assembly on which the pump is mounted. The drive housing assembly includes a gear on the lower end that meshes with the camshaft gear in the engine. This gear causes the cam in the drive housing to turn. The gear also operates the engine oil lubricating pump. Page 6341 Heater Core: Service and Repair Heater Hose Replacement HEATER HOSE REPLACEMENT Engine Heater Hose Routing (w/ Air Conditioning) The heater inlet hose is routed from the intake manifold to the inlet pipe of the heater core. The heater outlet hose is routed from the outlet pipe of the heater core to the inlet fitting of the coolant pump. Hoses are attached at each end with screw-type clamps. REMOVE OR DISCONNECT 1. Engine coolant. - Drain enough coolant into a clean container to lower the coolant level below the level of the lowest heater hose fitting. 2. Inlet and outlet hoses (72 and 70) at fittings. - Loosen the clamp screws enough to slide the clamps away from the fittings on the inlet and outlet hoses (72 and 70). - Remove the hose end by twisting and pulling. NOTICE: The heater core can be damaged if too much force Is applied on the core tubes During removal If the heater hose will not come off easily, cut off the hose forward of the heater core tube. Cut the hose remaining on the core tube lengthwise to remove it. 3. Hose Support clamps, brackets and/or retainers, as necessary. 4. Heater hose(s) (72 and 70) and clamps. INSTALL OR CONNECT 1. Healer hose(s) (72 and 70) and clamps. 2. Hose support clamps, brackets and/or retainers, if removed. 3. Inlet and outlet hoses (72 and 70) to fittings. - Apply rubber lubricant to the inside diameter of hose ends, If desired. - Slip a new hose clamp over one end of the hose and push the hose onto the heater pipe with a twisting motion. - Repeat the hose and clamp installation procedure at the other end of the hose. - Tighten clamp screw to 1.7 Nm (15 in. lb.). 4. Engine coolant. - Use the coolant drained earlier only if it is uncontaminated. Discard contaminated coolant and add fresh 50/50 coolant and water mixture. Page 5110 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 148 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Cooling System, A/C - Aluminum Heater Cores/Radiators Heater Core: Technical Service Bulletins Cooling System, A/C - Aluminum Heater Cores/Radiators INFORMATION Bulletin No.: 05-06-02-001A Date: July 16, 2008 Subject: Information On Aluminum Heater Core and/or Radiator Replacement Models: 2005 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2003-2005 HUMMER H2 Supercede: This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 05-06-02-001 (Section 06 - Engine/Propulsion System). Important: 2004-05 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX-COOL(R). Refer to the flushing procedure explained later in this bulletin. The following information should be utilized when servicing aluminum heater core and/or radiators on repeat visits. A replacement may be necessary because erosion, corrosion, or insufficient inhibitor levels may cause damage to the heater core, radiator or water pump. A coolant check should be performed whenever a heater core, radiator, or water pump is replaced. The following procedures/ inspections should be done to verify proper coolant effectiveness. Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if the radiator cap or surge tank cap is removed while the engine and radiator are still hot. Important: If the vehicle's coolant is low, drained out, or the customer has repeatedly added coolant or water to the system, then the system should be completely flushed using the procedure explained later in this bulletin. Technician Diagnosis ^ Verify coolant concentration. A 50% coolant/water solution ensures proper freeze and corrosion protection. Inhibitor levels cannot be easily measured in the field, but can be indirectly done by the measurement of coolant concentration. This must be done by using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale), or equivalent, coolant tester. The Refractometer uses a minimal amount of coolant that can be taken from the coolant recovery reservoir, radiator or the engine block. Inexpensive gravity float testers (floating balls) will not completely analyze the coolant concentration fully and should not be used. The concentration levels should be between 50% and 65% coolant concentrate. This mixture will have a freeze point protection of -34 degrees Fahrenheit (-37 degrees Celsius). If the concentration is below 50%, the cooling system must be flushed. ^ Inspect the coolant flow restrictor if the vehicle is equipped with one. Refer to Service Information (SI) and/or the appropriate Service Manual for component location and condition for operation. ^ Verify that no electrolysis is present in the cooling system. This electrolysis test can be performed before or after the system has been repaired. Use a digital voltmeter set to 12 volts. Attach one test lead to the negative battery post and insert the other test lead into the radiator coolant, making sure the lead does not touch the filler neck or core. Any voltage reading over 0.3 volts indicates that stray current is finding its way into the coolant. Electrolysis is often an intermittent condition that occurs when a device or accessory that is mounted to the radiator is energized. This type of current could be caused from a poorly grounded cooling fan or some other accessory and can be verified by watching the volt meter and turning on and off various accessories or engage the starter motor. Before using one of the following flush procedures, the coolant recovery reservoir must be removed, drained, cleaned and reinstalled before refilling the system. Notice: ^ Using coolant other than DEX‐COOL(R) may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50,000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX‐COOL(R) (silicate free) coolant in your vehicle. ^ If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost would not be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core and other parts. Page 6222 Compressor Clutch Hub: Specifications With SD-709 Compressor Clutch Hub Air Gap ....................................................................................................................................................... 0.49 - 0.79 mm (0.016 - 0.031 in.) Page 7619 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 5392 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Diagram Information and Instructions Parking Lamp: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Tires - Manufacturers' Assistance Tires: All Technical Service Bulletins Tires - Manufacturers' Assistance Group Ref.: Steering/ Suspension Bulletin No.: 323501 Date: December, 1993 INFORMATION SUBJECT: TIRE MANUFACTURERS' CONTACTS FOR ASSISTANCE MODELS: 1991-94 PASSENGER CARS AND TRUCKS General Tire has established a "Tire Fix" Department to assist you with anything from a tire adjustment to the location of the nearest General Tire dealer. "Tire Fix" representatives are available Monday through Friday from 8:00 A.M. to 6:00 P.M. Eastern Time at 1-800-847-3349. A General Tire Brochure is provided for review with all appropriate dealer personnel. A single contact point at General Tire can assist you with most aspects of their product to satisfy your customers' needs. Other tire manufacturers can be contacted for assistance at the Toll Free Numbers listed in illustration: Please retain this information for future reference. Page 5046 Neutral Safety Switch: Description and Operation Fig. 4 Mechanical Lockout. Except Tilt Column Fig. 5 Mechanical Lockout. Tilt Column Actuation of the ignition switch is prevented by a mechanical lockout system, Figs. 4 and 5, which prevents the lock cylinder from rotating when the selector lever is out of Park or Neutral. When the selector lever is in Park or Neutral, the slots in the bowl plate and the finger on the actuator rod align, allowing the finger to pass through the bowl plate in turn actuating the ignition switch. If the selector lever is in any position other than Park or Neutral, the finger contacts the bowl plate when the lock cylinder is rotated, thereby preventing full travel of the lock cylinder. Specifications Idle Speed/Throttle Actuator - Electronic: Specifications Terminal Resistance Values Terminal Resistance Values Terminals "A" to "B" 40 to 80 ohms Terminals "C" to "D" 40 to 80 ohms Terminals "B" to "C" Infinite ohms Terminals "A" to "D" Infinite ohms Page 4799 Brake Master Cylinder: Fundamentals and Basics Master Cylinder / Brake Pedal Relationship MASTER CYLINDER / BRAKE PEDAL RELATIONSHIP WARNING: Master Cylinders can be easily misdiagnosed for problems related to excessive brake pedal travel. Excessive brake pedal travel is often associated with a defective master-cylinder, however total pedal travel is affected by a wide variety of components and issues. Issues Affecting Pedal Travel Brake Fluid Page 5929 sure the retainer cup is tree from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. Important: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Except for the N9O 4X4 wheel used on T trucks, all light truck aluminum wheels will accept either "AW" series or "MO" series clip-on coated weights on both the inside and outside rim flanges. The N9O T truck wheel will accept "AW" series weights on the inside rim flange only. The outside rim flange is not designed to accept a clip-on weight. If such a weight installation is attempted, a poor fit will result, and the weight may fall off and/or cause cosmetic damage to the rim flange. This wheel can be 1) static balanced by clipping all the weight on the inside rim flange (as is done in the assembly plant), or 2) dynamic balanced by clipping a weight on the inside flange and using an adhesive weight near the outside flange. The charts show "AW" and "MC" balance weight usage. These original equipment coated weights are available at competitive prices through the GM Dealer Equipment program. Page 4972 Figure 7 Figure 8 Figure 9 Figure 10 Page 5066 Starter Solenoid: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 5579 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Vehicle Ride (Trim) Height Specifications Alignment: Specifications Vehicle Ride (Trim) Height Specifications Fig. 3 Vehicle Riding Height Measurement Locations & Specifications. 4 X 2 Models 4 X 2 MODELS Refer to Fig. 3, for ride height measurements and specifications. Fig. 4 Vehicle Riding Height Measurement Locations & Specifications. 4 X 4 Models 4 X 4 MODELS Refer to Fig. 4, for ride height measurements and specifications. Page 1496 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Page 7255 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 5166 Symbol Identification Page 1728 Valve Clearance: Adjustments VALVE ADJUSTMENT The VIN W engine does NOT have adjustable valve lash. When servicing the valve train requires removing and re-installing the rocker arms, tighten the rocker arm nuts to 27 Nm (20 ft. lbs.). Page 4864 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Locations Cargo Lamp Switch: Locations LH Side Of Instrument Panel. On LH Side Of Steering Column Applicable to: Except Bravada Odometer/Speedometer - ACDelco Service Center Locations Speedometer Head: All Technical Service Bulletins Odometer/Speedometer - ACDelco Service Center Locations File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-04A Date: September, 1996 INFORMATION Subject: AC Delco Service Center Locations for Odometer/Speedometer Service Models: 1997 and Prior Passenger Cars and Trucks (excluding Cadillac) This bulletin is being revised to provide the necessary contact information only. Please discard Corporate Bulletin Number 66-83-04 (Section 8 - Chassis/Body Electrical) General Motors provides service for sophisticated electronic products through the authorized AC Delco Service Center Program. This program is designed to provide GM vehicle owners with the highest quality and most technically up-to-date product available. Repair products from unauthorized service outlets are not acceptable as warranty replacements. Currently, there are 25 authorized AC Delco Service Centers who exchange and remanufacture odometer/speedometers (list included). Only these Centers should be contacted for service. Important: W series and 1997 T series Medium Duty truck odometer/speedometers must be ordered directly from GMSPO. The following steps should be taken when utilizing the AC Delco Service Centers: Dealers should contact their local AC Delco Service Center (list included). Any listed facility may be used. The following information must be provided: Part number VIN, Mileage, Vehicle Year, Make and Model Dealer Name and Address Delivery Date of Vehicle Name of the person requesting exchange or service Phone number Repair Order Number P.O. number (if non - warranty) Page 5219 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 5067 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 4L60 & 4L60-E Transmission Transmission Speed Sensor: Specifications 4L60 & 4L60-E Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Capacity Specifications Fluid - A/T: Capacity Specifications THM 180C Total 2.3 qt (US) Pan Only 1.5 qt (US) THM 1700-R4 Total 11.5 qt (US) Pan Only 5 qt (US) Page 3970 Seals and Gaskets: By Symptom Technical Service Bulletin # 467108 Date: 941201 A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Technical Service Bulletin # 467108 Date: 941201 Page 50 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 5619 10. Install flow control spring, control valve, O-ring seal and O-ring. 11. Install reservoir or return tube, then clips if equipped. System Bleeding 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine Off. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Service and Repair Blower Motor Switch: Service and Repair Wiring Harness Installation Control Assembly Page 3653 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Locations Air Intake Ducts 4.3W S/T Utility Page 4959 Neutral Safety Switch: Service and Repair Manual Transmission 1. Disconnect battery ground cable. 2. Disconnect back-up lamp switch electrical connector. 3. Disconnect switch wiring from transmission bracket, four-wheel drive vehicles only. 4. Remove switch from transmission. 5. Reverse procedure to install. Page 6192 Reassemble the Rotor and Bearing assembly to the front head of the compressor using Rotor & Bearing Installer J 26271-A. With Installer assembled to the Universal Handle 329886, as shown in Figure 23, force will be applied to the inner race of the bearing and the face of the rotor when installing the assembly onto the front head of the compressor. 5. Install rotor and bearing assembly retainer ring, using Snap Ring Pliers J 6083 (Fig. 9). 6. Apply sealer GM 12345382 (Loctite 242 or equivalent) to threads of pulley rim mounting screws. Install screws but do not torque the screws. 7. Rotate the pulley rim and rotor to insure that pulley rim is rotating "in-line". If pulley rim is distorted (does not rotate in-line), adjust or replace pulley rim. 8. Tighten pulley rim mounting screws to 11 N.m (100 in.lbs.) torque and lock screw heads in place by bending screw head washer similar to original crimp. 9. Reinstall Clutch Plate and Hub assembly. 6 Pole Clutch 6 POLE CLUTCH Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. Page 5895 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Isolation Diodes - Replacement Information Diode: Technical Service Bulletins Isolation Diodes - Replacement Information Number: 93-163-8A Section: 8A Date: MAY 1993 Corporate Bulletin No.: 178201R ASE No.: A6 Subject: ISOLATION DIODES REPLACEMENT INFORMATION Model and Year: 1993 AND PRIOR YEAR PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-47-8A, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS PART NUMBERS HAVE BEEN REVISED. THIS WILL ALSO UPDATE CERTAIN SERVICE MANUALS. ALL COPIES OF 92-47-8A SHOULD BE DISCARDED. Many of the electrical systems on our vehicles use a diode to isolate certain circuits and protect them from voltage spikes. Some of the circuits which may use such a diode are listed below: A/C Compressor Clutch ABS/4WAL NOTE: The ABS diode on the Delco Moraine system is hidden inside of an electrical connector under the carpet at the right kick panel. Wiper Charging System (hidden in wire harness) Parking Brake (vehicles with ABS) Relays Solenoids Diesel Glow Plug Circuit Day Time Running Lights Obtaining replacement diodes can sometimes be a problem. A universal diode, that meets the specifications in the chart below, may be used for the applications listed above. Since certain diode applications have specific part numbers, always reference the applicable GM parts catalogue before installing one of the universal diodes listed in this bulletin. When installing the new diode, use the following procedures to obtain a lasting repair: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to current flow direction, remove inoperative diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is needed to attach the new diode. 4. Check current flow direction of the new diode, being sure to install the diode with correct bias. Reference the appropriate service manual wiring schematic to obtain the correct diode installation position. Reference Figure 1 for replacement diode symbols and current flow explanations. ABS - Brake Bleeding Procedure Technical Service Bulletin # 931985 Date: 930501 ABS - Brake Bleeding Procedure Number: 93-198-5 Section: 5 Date: MAY 1993 Corporate Bulletin No.: 365003 ASE No.: A5 Subject: REVISED 4WAL BRAKE SYSTEM BLEEDING PROCEDURE Model and Year: 1990-93 M/L, S/T 1992-93 C/K 1993 G MODELS WITH 4WAL SERVICE UPDATE Bulletin Description THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-74-5 DATED OCTOBER 1990 TO UPDATE THE BLEED PROCEDURE AND TO ADD MODELS SINCE EQUIPPED WITH 4WAL BRAKE SYSTEMS. ALL COPIES OF 91-74-5 SHOULD BE DISCARDED. THIS BULLETIN ALSO UPDATES INFORMATION IN 1993 M/L SERVICE MANUAL, 1993 S/T SERVICE MANUAL, 1993 C/K SERVICE MANUAL, 1993 G SERVICE MANUAL, AND STG RWAL/4WAL 1988-1991 APPLICATIONS MANUAL 15005.05 (VERSIONS 2 TO 5). PLEASE PLACE A COPY OF THIS BULLETIN IN EACH MANUAL. THIS BULLETIN IS EQUIVALENT TO SERVICE MANUAL UPDATE BULLETIN 93-12-5, DATED SEPT. 1992. This 4WAL brake system bleed procedure is the most efficient bleed procedure to date. The 4WAL Brake Pressure Modulator Valve (BPMV), formerly called Electro Hydraulic Control Unit (EHCU), should be bled after replacement or if air is suspected to be trapped inside the unit. There are two conventional methods to use when bleeding the 4WAL BPMV: (1.) Pressure Bleeding or (2.) Manual Bleeding. IMPORTANT: There are two internal bleed screws (brass colored), one on each side of the BPMV, that open internal channels. Open the internal bleed screws 1/4 to 1/2 turn before bleeding (figure 2). New 4WAL BPMV's are shipped with the internal bleed screws open, so first close the internal bleed screws until snug, then open 1/4 to 1/2 turn. NOTICE: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Clean any fluid that may drip onto wheel cylinders or calipers to prevent corrosion. Always re-seal and wipe off brake fluid containers to prevent spills. Tools Required Page 7096 Note: Some technicians may apply a small cord (wire, plastic tube, etc.) behind or underneath moldings that remain on the vehicle to improve sanding and painting. If the vehicle paint system is baked with cord in place, damage to some moldings may occur. If this technique is used, DO NOT BAKE PAINT air dry only Note: Only items marked with an asterisk are "add" conditions to the Major Operation being performed. Removal time for all other items listed is included in the refinish time. LIGHT DUTY TRUCKS C/K TRUCKS Grille Front bumper filler panel Antenna Tail lamps Door edge guards Metal wheel opening moldings *Roof marker lamps "Luggage rack *West coast style mirrors "Stripes Emblems/decals if necessary Swing out windows/seals Tail gate handle bezel S/T TRUCKS Windshield molding Bumper filler panels, Ft./Rr. Wiper arms Antenna Wheel opening moldings Cowl vent grille Door edge guards Side view mirrors Tail lamps *Wind deflector Rear Window (Jimmy) *Luggage rack *Stripes Emblems/decals if necessary Swing out windows/seals *Spare tire carrier and latch-external mount (Jimmy) M/L VANS Windshield molding Wheel opening moldings Headlamp bezels Antenna Tail lamps Door edge guards *Luggage rack *Stripes Emblems/decals if necessary R/V TRUCKS Wiper arms Cowl vent grille Antenna Tail lamps Page 5087 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 2846 allowing the control module to make adjustments for different altitudes. The control module uses the MAP sensor to control fuel delivery and ignition timing. Test Description: Numbers below refer to circled numbers on the diagnostic chart. Important ^ Be sure to use the same diagnostic test equipment for all measurements. 1. Checks MAP sensor output voltage to the control module. This voltage, without engine running, represents a barometer reading to the control module. ^ When comparing Tech 1 "Scan" readings to a known good vehicle, it is important to compare vehicles that use a MAP sensor having the same color insert or having the same "Hot Stamped" number. 2. Applying 34 kPa (10" Hg) vacuum to the MAP sensor should cause the voltage to change. Subtract second reading from the first. Voltage value should be greater than 1.5 volts. Upon applying vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicated a faulty sensor. 3. Check vacuum hose to sensor for leaking or restriction. Be sure that no other vacuum devices are connected to the MAP hose. NOTE: Make sure electrical connector remains securely fastened. 4. Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connection. Output changes greater than .1 volt indicates a bad connector or connection. If OK replace sensor. Wiring Diagram For Code 33 - MAP Sensor Circuit (Signal Voltage High - Low Vacuum) ECM Circuit MAP Sensor Circuit (PCM) PCM Circuit Page 5617 Fig. 8 Thrust plate removal Prior to disassembly of the pump, remove filler cap and drain fluid. If broken components or foreign materials are found during disassembly, the hydraulic system should be disassembled, inspected, cleaned and flushed before service is complete. Refer to Fig. 1, for pump disassembly. 1. Clean exterior of pump with solvent, then clamp front hub of pump into a soft jaw vise. 2. Pry tab and slide retaining clip off of pump, Fig. 2. 3. Remove reservoir, then return tube as follows: a. Assemble five 5/8 inch washers and a 9/16 inch-12 nut outside of tube, Fig. 3. b. Plug tube to prevent chips from entering, then insert a 9/16 X 12 tap into return tube and turn until tube is pulled out of housing, Fig. 3. 4. Remove O-ring, fitting, O-ring seal, flow control valve and spring. Fig. 4. 5. Using snap ring pliers, remove retaining ring. Note position of large lug in housing before removal. Fig. 5. 6. Remove driveshaft and bearing, Fig. 6. Note and measure any clearance between collar and shaft. Press bearing from shaft using a support ring under bearing. 7. Remove driveshaft seal by prying seal loose with a screwdriver. 8. Insert a punch into access hole, then pry retaining ring loose with a screwdriver, Fig. 7. 9. Using a 5/16 inch piece of bar stock or a suitable brass drift, remove thrust plate, Fig. 8. 10. Remove pump ring, rotor, vanes and dowel pins. 11. Remove pressure plate and O-ring, then the spring, seal and remaining dowel pin. 12. Using a suitable punch, remove sleeve assembly. Inspection 1. Clean all parts with solvent and blow dry. 2. Inspect rotating components as follows: a. Vane tips for scoring or wear. b. Fit of vanes in rotor. Vanes must fit properly in slots without sticking or excessive play. c. Rotor slots for burrs and excessive wear at thrust faces. d. Inner surface of pump ring for scoring or wear. e. Thrust plate and pressure plate for wear on plate surfaces. f. If heavy wear is present, or parts are faulty, replace entire rotating group. 3. Inspect bearing for rough or looseness and bearing seal for leakage, cracking or swelling. 4. Check driveshaft and bearing bore for excessive burning or scoring. 5. Control valve must move smoothly in the valve bore. Assembly Fig. 9 Dowel pin installation Page 6103 6. Blower motor (53). 7. Electrical connectors from blower motor (77) and resistor (78). 8. Engine coolant. - Use the coolant drained earlier only if it is uncontaminated. Discard contaminated coolant and add fresh 50/50 coolant and water mixture. Fuel - Removal And Installation of CPI Fuel Line Clips Fuel Supply Line: All Technical Service Bulletins Fuel - Removal And Installation of CPI Fuel Line Clips BULLETIN NO: 93-6C-46 SECTION: 6C NUMBER: 3 CORPORATE REFERENCE NO: 266306 DATE: February, 1993 SUBJECT: INFORMATION ON INSTALLATION OF CPI FUEL LINE CLIPS MODELS: 1992-93 S/T AND M/L MODELS WITH 4.3L ENGINES (RPO L35) Improper installation of the fuel line clips which hold the fuel inlet and outlet tubes to the Central Port Fuel Injection (CPI) unit may result in an internal CPI fuel leak. A fuel leak may cause driveability problems or in extreme cases, hydrolock. Proper Removal and Installation of Fuel Line Clips: Removal Using needle nose pliers, firmly grasp the fuel fitting clip as shown in Figure 1 and pull the clip straight back from the fuel meter body. It may be necessary to lift the opposite side of the clip with a screwdriver. Discard the clip. Installation Always use a new clip and 0-rings (P/N 17112702). Using your fingers as shown in Figure 2, slide the clip over the fuel meter body making sure that the clip properly engages the slots in the fuel inlet and outlet tubes and that the clip is properly positioned over the fuel meter body on both the top and bottom sides. The clip will be properly positioned when the flanges on the fuel meter body protrude from the clip and the clip snaps in place. Important Do not install the clip from the bottom-up position, the clip will not properly retain the fuel lines. Install the clip from the top-down position as shown in Figure 2. Secondly, it is important to note that the fuel lines MUST be in the correct inlet/outlet openings (The lines will fit either opening). Lastly, the fuel lines MUST be correctly seated into the TB body to allow for proper installation of the clips. Page 8393 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 1116 The dexos (TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos (TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos (TM)specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 2(TM) engine oil. GM dexos 2(TM) Engine Oil Specification - dexos 2(TM) is approved and recommended by GM for use in Europe starting in model year 2010 vehicles, regardless of where the vehicle was manufactured. - dexos 2(TM) is the recommended service fill oil for European gasoline engines. Important The Duramax(TM) diesel engine is the exception and requires lubricants meeting specification CJ-4. - dexos 2(TM) is the recommended service fill oil for European light-duty diesel engines and replaces GM-LL-B-025 and GM-LL-A-025. - dexos 2(TM) protects diesel engines from harmful soot deposits and is designed with limits on certain chemical components to prolong catalyst life and protect expensive emission reduction systems. It is a robust oil, resisting degradation between oil changes and maintaining optimum performance longer. Disclaimer Page 5274 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Engine - Hard Start Or No Start Fuel Pressure Pulsation Damper: All Technical Service Bulletins Engine - Hard Start Or No Start File In Section: 6E Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator. The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks. If the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description Qty 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty. use: Labor Op Description Labor Time Use Published Labor J 5590 Pump, Fuel R&R; Operation Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Page 1333 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 6169 Removing Pulley Rotor And Bearing Assembly 3. Install pulley rotor and bearing puller guide 3 33023-A to the front head and install J 33020 pulley rotor and bearing puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots in the rotor. 4. Hold the J 33020 puller in place and tighten the puller screw against the puller guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal the rotor hub must be properly supported. Pulley Rotor Bearing Removal Remove the forcing screw from J 33020 puller and, with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks. 6. Drive the bearing out of the rotor hub with rotor bearing remover J 9398-A and J 29886 universal handle. NOTICE: It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Less Hydraulic Clutch System Clutch Pedal Assembly: Service and Repair Less Hydraulic Clutch System 1. Disconnect battery ground cable, then remove coffer pin and washers from clutch pedal rod. 2. Remove clutch start switch, noting position for installation reference, then the nut, bolt and washers from clutch pivot arm. 3. Remove clutch pivot arm, pedal rod and bushing. Release retracting spring by depressing pedal, moving pedal laterally and releasing. 4. Remove pedal and bushings, then the bumper, if worn or damaged. 5. Reverse procedure to install. Adjust clutch linkage as described under "Clutch, Adjust." Refer to Clutch/Adjust Page 6170 Installing Pulley Rotor Bearing 1. Place the pulley rotor on the J 21352-A support block to fully support the rotor hub during bearing installation. NOTICE: DO NOT support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent. 2. Align the new bearing squarely with the hub bore and using puller and bearing installer J 9481-A with universal handle J 29886, drive the bearing fully into the hub. The installer will apply force to the outer race of the bearing. Staking Bearing In Rotor Hub Bore 3. Place bearing staking guide J 33019-1 and bearing staking pin J 33019-2 in the hub bore. Shift the rotor and bearing assembly on the 321352-A support block to give full support of the hub under the staking pin location. A heavy duty rubber band may be used to hold the stake pin in the guide, and the stake pin should be properly positioned in the guide after each impact on the pin. 4. Using care to prevent personal injury, strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to but not touching the bearing. Turbo Hydra-Matic 3L30 (180C) Fluid - A/T: Service and Repair Turbo Hydra-Matic 3L30 (180C) Draining Bottom Pan 1. Raise and support vehicle. 2. Position a suitable drain pan below transmission oil pan. 3. Remove front and side oil pan bolts. 4. Loosen rear bolts and gently pry the pan down to allow fluid to drain. 5. Remove remaining bolts and pull pan away from case carefully, as there will still be fluid contained in the pan. 6. Drain remaining fluid from pan, then remove gasket, oil filter retaining bolts, oil filter and seal. 7. Using solvent, thoroughly clean oil pan and gasket surfaces, then air dry. 8. Install new oil seal and filter into case. Torque attaching bolts to 13-15 ft. lbs. 9. Install oil pan with new gasket and torque bolts to 7-10 ft. lbs. 10. Add transmission fluid, then with engine idling and brakes applied, move selector lever through each gear range and return selector lever to Park. 11. Bring fluid to proper operating temperature and check fluid level, adding as required to bring level to the Full mark. Adding Fluid to A Dry Transmission 1. Add transmission fluid. 2. With transmission in Park, start engine and let engine idle (carburetor off fast idle cam.) 3. Apply brakes and move shifter lever through each gear range, then with transmission in Park, add additional fluid as required to bring the level up to Full mark on dipstick. Page 6819 Coolant Temperature Sensor Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Sensor HP Engine RH Front Side Of Engine. Front Of Engine Applicable to: 4.3L/V6-262 HP Engine Page 8370 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7688 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 2897 ECM QDR Check Procedure Aluminum Wheels - Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Page 8687 Disclaimer Locations RH I/P Harness Wiring Page 6268 Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode wire ends to protect the diode from excess heat. Follow the manufacturers instructions for the solderin equipment you are using. 5. Install terminal(s) into the connector body if previously removed in step number 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion completely cover all exposed wire and diode attachment points. NOTE: A universal diode with a 3 amp, 400 PIV (Peak Inverse Voltage) rating can be used in all of the previously mentioned applications. The following 1993 Service Manuals will need to be updated with the correct part numbers and rating changes. Carline Page All J, L, W, and UO 8A-5-12 Heat sink, part number 276-1567, can be obtained from Radio Shack. We believe the diodes and heat sink listed in this article as well as their manufacturer to be reliable. There may be additional manufacturers or equivalent products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. Page 7242 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 4937 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Radio - Buzzing Noise in AM Band With Engine Running Radio/Stereo Noise Filter: Customer Interest Radio - Buzzing Noise in AM Band With Engine Running Group Ref.: Accessories Bulletin No.: 449601 Date: April, 1994 SUBJECT: BUZZING NOISE IN AM BAND OF RADIO (INSTALL FILTER ON PCM/TCM) MODELS: 1992-94 CHEVROLET AND GMC TRUCK C/K, S/T TRUCKS AND M/L, G VANS 1992-94 OLDSMOBILE BRAVADA WITH 4L60-E AND 4L80-E TRANSMISSIONS CONDITION: Some owners may comment of a buzzing noise in the low end of the AM radio band with the engine running. CAUSE: The switching of the force motor in the electronic transmission emits an RFI signal through the PCM/TCM. The AM band of the radio is receiving this interference through the antenna. CORRECTION; To determine if this is the cause of the owner's comments. first duplicate the condition and then disconnect the electrical connector at the transmission (this will disable the force motor). If the condition improves. install an in-line filter (P/N 1224205) to the ignition lead (ckt 439) of the PCM/TCM. Some applications may have two (439 ckt), in which case, a filter will be required for each lead. NOTE: Disconnecting the electrical connector at the transmission will set the transmission diagnostic codes. It will be necessary to remove these codes after the corrective action has been performed. IMPORTANT: Discard the instructions in the filter package. This filter Is an in-line filter with a single lead on one end and two leads on the other end (one lead being black (ground). Install this filter as close to the PCM/TCM connector as possible. It Is important to Install the filter with the single lead end going toward the PCM/TCM and then take the black (ground) lead back and attach it to the case of the PCM/TCM. If this filter is installed incorrectly, the condition will become worse. SERVICE PARTS INFORMATION: Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Page 3615 Electronic Spark Control (ESC) Circuit Circuit Description: The Code 43 circuit consists of two knock sensors with one wire that goes directly to the ECM. There are two Code 43 checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 4.4 volts. If voltage is either too high or too low for 2 or more seconds, Code 43 will set. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3800 rpm, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, Code 43 will set. Diagnostic Aids: The ECM applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the ECM, is able to read this signal as knock and incrementally retard spark. If the ESC system checks OK, but detonation is the complaint, See: Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Page 8024 Fuel Pump And Sender Assembly (Typical) Page 301 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 7572 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Removal & Installation Distributor: Service and Repair Removal & Installation Distributor And Coil 4.3L Engine REMOVE/DISCONNECT NOTE Verify ignition switch is "OFF". 1. Wiring harness connectors at side of distributor. 2. Coil wire and sparkplug wires on either left or right side of distributor. 3. Distributor cap by two screws and set to side: - Bring engine to TDC on the compression stroke for #1 cylinder and align timing marks to 0~ . Scribe a mark on distributor housing in line with rotor. - Scribe a mark on engine in line with rotor. Note position of distributor housing in relation to engine. 4. Remove distributor bolt hold-down clamp, raise distributor noting rotor rotation, then remove distributor and gasket (if applicable). Do not rotate crankshaft with distributor removed from engine. INSTALL/CONNECT NOTE To ensure correct timing of distributor it must be installed with rotor correctly positioned as noted in Step 3 of the removal procedure. Line up rotor, mark on distributor housing, and mark on engine. If distributor shaft won't drop into engine, insert a screwdriver into cavity for distributor and turn oil pump driveshaft. 1. Distributor and gasket (if applicable). 2. Hold-down clamp and tighten bolt to 34 Nm (25 lb. ft.). 3. Distributor cap. 4. Wiring harness connectors at side of distributor. 5. Sparkplug wires and coil wires. 6. Check engine timing. Page 6370 C. Parts Information D. Warranty Information 1. Vehicle Still in Warranty 2. Customer Paid' Retrofitting Costs 3. Labor Time Information Notes on Retrofit Important: Before proceeding with any retrofit, make sure you have all component Parts required on hand to perform a proper and complete repair with Minimal downtime. R-12 Removal Prior to Retrofit To prepare a system for retrofitting, the R-12 must be recovered and the system must be completely evacuated. Evacuation is necessary to insure that small amounts of R-12 and air remaining in the system are removed. This will prevent cross contamination of the two refrigerants, which could lead to reduced A/C system reliability and performance. It is very important that the specified times for waiting after recovery and evacuation not be reduced. This time is required to sufficiently remove residual R-12 from the oil in the system. A considerable amount of testing has determined that the following procedure is required to achieve satisfactory results and conform to SAE J 1661: 1. Inspect Condition of Vehicle Install the gauge set on the high and low side ports. Use normal diagnostic procedures to find the cause of the vehicle's reported condition. One of three conditions will exist with the refrigerant system: a. System pressure correct, no leaks - proceed to Step 2 (Recovery). This would normally apply when: 1. The system must be recovered/recharged for a repair to a system other than the A/C system, or 2. Where the A/C system condition did not involve leaks, but requires recovery/recharge to replace a component. b. Compressor not operating, but some charge. Leak test to find the leak, complete Step 2 (Recovery), then correct the leak before proceeding with Step 3 (Conversion port installation). c. No charge in system - proceed with the Conversion port installation in Step 3. Use the ACR4 to evacuate for 5 minutes. If the leak can be heard, repair the leak. If the leak cannot be heard, charge with 1/2 pound of R-134a. Leak test with the J 39400 Leak Detector, recover the R-134a, repair any additional leaks found, and proceed with the evacuation in Step 5. 2. Recover the R-12 from the System Notice: THIS PROCEDURE IS DIFFERENT THAN THE NORMAL (NON-RETROFIT) RECOVERY PROCEDURE. R-12 will be recovered through the HIGH SIDE SERVICE PORT ONLY, WITH THE ENGINE RUNNING. Recovery through the low side will not effectively remove the R-12 from the accumulator, resulting in possible damage to the retrofitted system. Important: Vehicle must be above 50° F (10° C) to allow for complete recovery of the R-12. If it is not, either allow it to warm up in the shop overnight, or increase the evacuation time in Step 5.a to 30 minutes. a. Connect the recovery hose from the R-12 recovery cart (ACR3) to the middle port of the A/C gauge set. Open the oil drain valve on the ACR3 cart long enough to drain the oil. Failure to do so could cause excessive amounts of oil to build up in the separator, resulting in damage to the recovery cart compressor. b. Start the engine. Leave the hood up, and the windows open. On vehicles with manual A/C controls, set the A/C controls to normal A/C mode, high blower, and temperature control to full cold. On cars with automatic A/C controls, set the temperature to 75° F, "AUTO" mode, and manually select high blower. Page 147 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Page 7214 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Locations LH I/P Harness Wiring Engine - Hard Start or No Start Fuel Pressure Pulsation Damper: All Technical Service Bulletins Engine - Hard Start or No Start File In Section: 6E - Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks It the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description QTY 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Labor Op Description Labor Time J 5590 Pump, Fuel R&R; Use Published Labor Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Steering Wheel - Self Aligning Safety Information Steering Wheel: Technical Service Bulletins Steering Wheel - Self Aligning Safety Information Number: 92-22-3B Section: 3B Date: SEPT. 1991 Corporate Bulletin No.: 170103 ASE No.: A4 Subject: SELF-ALIGNING STEERING WHEEL INFORMATION Model and Year: 1992 CAVALIER AND T1 TRUCKS Concerned with injuries related to driver involvement with the steering system during accidents, General Motors developed the energy absorbing steering column in the mid 1960s. It was designed to collapse in a controlled fashion to help dissipate the energy of the driver during the rapid deceleration of a collision. In a frontal impact, with a properly adjusted safety belt, the steering wheel is designed to distribute the impact load primarily through the driver's chest and shoulders. While this system does an excellent job of reducing potential injuries, the fact is that a high level of energy must be dissipated, in a short time, through the steering column. Because of this, the driver's involvement with the steering system is still a major source of crash related injuries. In 1982, the National Highway Traffic Safety Administration attributed almost 27 percent of all crash related injuries to involvement with the steering system. GM Research Laboratory data has confirmed that driver impact with the steering wheel can cause a variety of injuries to soft tissue organs, face, neck and spine. General Motors customers have a new safety feature in their vehicles steering systems thanks to improved safety technology developed by GM. To enhance the safety performance of the steering wheel, GM Research Laboratories joined with GMs' Inland Fisher Guide Division and various other GM Divisions to develop an energy absorbing steering wheel assembly. This combined effort resulted in the self-aligning steering wheel which will be standard equipment on 1992 J cars and T trucks. In the event of a front-end collision where the driver hits the steering wheel, the wheel will align itself parallel with the driver's chest and abdomen no matter how the driver hits it. This self-aligning motion helps spread the force of the impact and helps prevent injuries. Page 2280 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature (ECT) Sensor Engine Coolant Temperature (ECT) W Engine Wiring, RH Side Two Wheel Drive - 2WD Wheel Bearing: Adjustments Two Wheel Drive - 2WD FRONT WHEEL BEARINGS ADJUSTMENT 4 X 2 MODELS 1. Raise and support front of vehicle. 2. Remove hub dust cover, then the cotter pin. 3. While rotating wheel assembly in forward direction, torque spindle nut to specification to fully seat the bearings. 4. Loosen nut to the ``just loose'' position, then tighten the spindle nut finger tight. 5. If either spindle hole does not line up with a spindle nut slot, back off spindle nut not more than 1/2 nut flat. 6. Install new cotter pin, then measure hub endplay. Endplay should be .001-.005 inches when properly adjusted. 7. Install hub dust cover and lower vehicle. 4 X 4 MODELS These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Page 8560 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 7050 On a clean surface, at or above room temperature, firmly apply a 2" wide piece of masking tape and pull upward quickly. DO NOT USE duct tape, cloth backed tape or other aggressive tapes. If the colorcoat flakes or peels away from the ELPO (leaving the ELPO intact) the colorcoat is delaminating and the vehicle should be repaired using the "Paint Repair Procedure" contained in this bulletin. This test SHOULD ONLY BE APPLIED TO A VEHICLE SHOWING THE CONDITION, (peeling/delamination) and NOT in areas of stone chipping or other obvious damage. These "other" conditions should be repaired following standard paint repair procedures. CORRECTION Refinish the ENTIRE BODY ABOVE THE BODY SIDE MOLDINGS using the following repair procedure. It is important that ALL surfaces above the body side moldings (including recessed areas around door handles) be refinished, as these surfaces may show the same DELAMINATION (peeling) condition at a later date. Note: Many vehicles have some type of plastic exterior body panels (cowl vent grilles, fascias, front end panels, rear fenders, etc.). These panels are not subject to DELAMINATION and therefore do not require refinishing. If painting of these panels is required for color uniformity, scuff sand and colorcoat only (and clearcoat if basecoat/clearcoat system is used). Note: Two tone lines, feature lines or body side molding treatments near mid-door height are appropriate break lines. If no such convenient break lines are present, the entire panel above the next lower break line must be refinished and the portion of the panel below that break line should be COLORCOATED ONLY (and clearcoated if basecoat/clearcoat system is used) for color uniformity of the repair. Note: Pickup boxes which are covered by caps, bedliners or tonneau covers do not receive direct exposure to sunlight, and normally would not be repaired under this procedure. However, if the inside of the box has been uncovered and experienced DELAMINATION, use the appropriate Labor Operation Number. Note: Certain two tone applications on trucks using the high potential colors (Blues, Grays and Silvers) may require that only portions of the vehicle surface be refinished. Examples would be: Example 1. Blues, Grays and Silvers as "insert colors" on vertical surfaces with other, non-high potential colors above the insert (or break line). Action: Refinish the "insert color" only, between the break line and body side molding (or to the lower feature line on certain vehicles). Example 2. Blues, Grays and Silvers on surfaces above the break line with other, non-high potential colors as "insert colors". Action: Refinish the surfaces above the "insert color" or break line only. Example 3. Blues, Grays and Silvers used as both the primary and "insert colors". Action: Refinish both high potential color surfaces above the body side moldings (or to the lower feature line on certain vehicles). Vehicles should be repaired with the same type materials they were manufactured with; repair basecoat/clearcoat with basecoat/clearcoat materials and monocoat with monocoat. PAINT REPAIR PROCEDURE 1. Some vehicle components will be removed from the vehicle while others will require masking. The list located at the end of this bulletin will establish the removal items. Items not found on the list and non-repair areas are to be masked. 2. Prior to removing the paint finish, clean the area to be refinished with an appropriate wax and grease remover to remove any contaminants. 3. Remove the original finish of paint down to the ELPO primer surface using an orbital D.A. sander, leaving the ELPO surface intact. This can be done in "stages" using 80 grit (or finer) discs to remove the majority of coating, followed with 180 grit (or finer) discs to remove the remainder of material down to the ELPO surface and any chalky residue or degraded ELPO that may remain. Avoid sanding through ELPO to bare metal in order to retain maximum corrosion protection. - An alternative in some geographic areas may be plastic media blasting such as may be provided by members of: - Dry Stripping Facilities Network 1-800-634-9185 * Locations Electronic Spark Control (ESC) Module Page 5428 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Specifications Stabilizer Shaft: Specifications Stabilizer Bar Clamp 24 ft.lb Stabilizer To Link Bolt 33 ft.lb Page 7248 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 2969 Oxygen Sensor: Service and Repair NOTE The Heated Oxygen Sensor (HO2S) uses a permanently attached pigtail and connector. This pigtail should not be removed from the Heated Oxygen Sensor (HO2S). Damage or removal of the pigtail or connector could affect proper operation of the oxygen sensor. Take care when handling the Heated Oxygen Sensor (HO2S). The in-line electrical connector and louvered end must be kept free of grease, dirt, or other contaminants. Also, avoid using cleaning solvents of any type. Do not drop or roughly handle the heated oxygen sensor. If the heated oxygen sensor pigtail wiring, connector or terminal is damaged, the entire oxygen sensor assembly must be replaced. Do not attempt to repair the wiring, connector or terminals. In order for the sensor to function properly, it must have provided to it a clean air reference. This clean air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors or terminals could result in the obstruction of the air reference and degraded oxygen sensor performance. CAUTION The following guidelines should be used when servicing the heated oxygen sensor: ^ Do not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor causing poor performance. Also, the sensor pigtail and harness wires must not be damaged in such a way that the wires inside are exposed. This could provide a path for foreign materials to enter the sensor and cause performance problems. ^ Neither the sensor or vehicle lead wires should be bent sharply or kinked. Sharp bends, kinks, etc., could block the reference air path through the lead wire. ^ Do not remove or defeat the oxygen sensor ground wire (where applicable). Vehicles that utilize the ground wired sensor may rely on this ground as the only ground contact to the sensor. Removal of the ground wire will also cause poor engine performance. ^ The Heated Oxygen Sensor (HO2S) may be difficult to remove, when engine temperature is below 48°C (120°F). Excessive force may damage threads in exhaust manifold or exhaust pipe. NOTE The engine harness may be repaired using Packard's Crimp and Splice Seals Terminal Repair Kit J 38125-A. Under no circumstances should repairs be soldered since this could result in the air reference being obstructed. Remove or Disconnect 1. Negative battery cable. 2. Electrical connector releasing locking tab. 3. Carefully back out oxygen sensor. Install or Connect NOTE A special anti-seize compound is used on the Heated Oxygen Sensor (HO2S) threads. The compound consists of liquid graphite and glass beads. The graphite will tend to burn away, but the glass beads will remain, making the sensor easier to remove. New, or service replacement sensors will already have the compound applied to the threads. If a sensor is removed from an engine, and if for any reason it is to be reinstalled, the threads must have anti-seize compound applied before reinstallation. 1. Coat threads of heated oxygen sensor with anti-seize compound (GM PIN 5613695 or equivalent), if necessary. 2. Sensor, and torque to 41 Nm (30 ib. ft.). 3. Electrical connector. 4. Negative battery cable. Page 5114 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Engine - Tick Or Rattle/Detonation Or Rattle Noise Intermediate Shaft: All Technical Service Bulletins Engine - Tick Or Rattle/Detonation Or Rattle Noise FILE IN SECTION: 6 - Engine BULLETIN NO.: 23-61-11 DATE: June, 1995 SUBJECT: CPI Engine Noise (Install New Gears/New MEM-CALs) MODELS: 1992 Chevrolet and GMC Truck S/T, M/L Models 1992 Oldsmobile Bravada with 4.3L CPI Engine (VIN W - RPO L35) This bulletin is being revised to update engine scrapping information. Previous divisional publication numbers were: Chevrolet 92-244B-6 GM of Canada 93-6A-121 GMC Truck 92-6A-153A Oldsmobile 92-T-168 CONDITION Some 1992 model year 4.3L CPI engines may exhibit one or both of the following noises: I. A tick or rattle noise at idle or low engine speeds up to 1300 RPM. The noise may occur hot or cold in Park/Neutral or in gear. II. A detonation or rattling type noise under acceleration at engine speeds between 2000 - 2500 RPM. It is usually most noticeable at the shift points under moderate acceleration with the transmission torque converter unlocked. Premium grade fuel does not affect the noise. III. If an engine has both noises (conditions "I" and "II"), follow condition "II" for cause and correction instructions and information. CAUSE I. The most probable cause for the idle tick or rattle (condition I) is due to zero or near zero lash between the balance shaft drive gears. Some gears may feel as if the lash is acceptable but there is most likely an area on one of the teeth which is not meshing properly with the other gear. II. The source of the detonation or rattling type noise under acceleration between 2000 - 2500 RPM (condition II) is the rear balance shaft needle bearing. With some engines, the rear needle bearing is excited by a combination of factors (i.e., engine case, combustion events, balance shaft gear lash, valve train torque reversals, cam chain play, needle bearing clearance, etc.). Important: If there is any question about the proper diagnosis of the noise, call Technical Assistance. The unnecessary customer inconvenience and/or replacement of parts must be avoided. It is important to note that neither noise is a reliability or dependability concern. The noises are a customer pleasability issue only. The life of the engine will not be shortened due to the above causes. CORRECTION I. The following steps should be followed to correct an idle tick noise (condition I). 1. Remove the accessory drive belt. 2. Start the engine and note the noise. If it is still present proceed to step "3"; if not, proceed with diagnosis of accessory drive per the service manual procedures. Important: Do not allow the engine to operate for an extended period of time with the accessory drive belt off. Remember the water pump and fan are not functioning. Overheat will eventually occur. 3. Order GMSPO B/S Gear Kit # 12513234 and W/P; front cover gaskets. Use the following steps to replace the balance shaft gears. Troubleshooting Power Steering Pump: Testing and Inspection Troubleshooting Fig. 1 Troubleshooting power steering system Page 4667 For more information on how to use a disc brake micrometer see Fundamentals and Basics. See: Fundamentals and Basics PARALLELISM Parallelism is the measurement of the thickness of the rotor at 12 or more points around the circumference of the rotor. All measurements must be made at the same distance in from the edge of the rotor. Lack Of Parallelism Lack Of Parallelism The rotor thickness must not vary more than 0.013 mm (0.0005-inch) from point to point. Page 1474 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Page 4731 4. Install J 39177 on the combination valve (figure 2). 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described in SECTION 5. 7. Close the internal bleed valves. TIGHTEN * Internal bleed valves (A) to 7 N-m (60 lbs.In.). 8. Remove the three J 39177 Combination Valve Pressure Bleeding Tools. 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the Ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure as many times as needed to remove the remaining air in the hydraulic system. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. Page 7700 Key-In Warning Alarm Does Not Operate Lamps-On Warning Alarm Does Not Operate Page 8338 B. Locate the two grille to fender fasteners at the bottom of the grille (one on each side). These can be either Christmas Tree style retainers or bolts: a. If the grille has Christmas Tree style retainers, it is NOT necessary to remove them. b. If the grille has two grille to fender bolts, remove them. C. Disconnect the side marker lamp connectors. 2. From the back side of the grille, apply clear G.M.S. sealer (P/N 1052915 or equivalent), along the entire leading edge of the side marker lamp(s) (Figure 1, View A). 3. Reinstall the grille. A. If the grille is equipped with Christmas Tree style retainers, one on each side of ghlle, snap the grille in place prior to torquing the remaining fasteners. If required, replace the Christmas Tree style retainers (P/N 15672328). B. If the grille is equipped with two grille to fender bolts located at the bottom of the grille, one on each side, instead of Christmas Tree style retainers, reinstall the bolts and torque them to 1.6 - 2.2 N-m. (13-18 lbs.in.). C. Torque the remaining eight fasteners located across the top of the grille and within the egg crate area to 1.2 - 1.6 N-m. (10-13 lbs.in.). SERVICE PARTS INFORMATION Part Number Description Qty/Veh 1052915 G.M.S. Sealer-Type A As Required 15672328 Retainer-Radiator Grille As Required Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B1308 Use applicable labor time guide for labor hours. Inline Fuse, Trailer Towing Harness Fuse: Locations Inline Fuse, Trailer Towing Harness Center Of Dash Panel, In Engine Compartment Page 5383 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 1662 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Locations Junction Block Wiring Page 3018 Upshift Indicator: Description and Operation Manual Transmission Shift Light Circuit PURPOSE The Manual Transmission Shift Light provides a display which indicates to the driver the optimum fuel economy point for upshifting the manual transmission based on engine speed and load. OPERATION Activation of the control module driver turns the lamp "ON". The Shift Light will stay "ON" for up to 5 seconds, so as to urge the driver to shift-up. The control module uses information from the following inputs to control the shift light: Engine Coolant Temperature (ECT) sensor. - Throttle Position (TP) sensor. - Vehicle Speed Sensor (VSS). - Engine RPM. The Shift Light will dim slightly when the headlights and/or parking lights are turned "ON". This is to give better driver visibility through the windshield. LOCATION The display lamp is on instrument panel. Page 3590 Rear Of Engine Page 6166 Shaft Key, Clutch Plate/Hub Installation 1. Install the shaft key into the hub key groove. Allow the key to project approximately 3.2mm (1/8") out of the keyway. The shaft key is curved slightly to provide an interference fit in the hub key groove. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the clutch plate and hub assembly. 3. Align the shaft key with the shaft keyway and place the clutch plate and the hub assembly onto the compressor shaft. Installing Clutch Plate & Hub Assembly Locations Backup Lamp Switch: Locations Rear Engine Components. LH Side Of Transmission Applicable to: 1991-92 4.3L/V6-262 Engine, Except Bravada & Automatic Transmission Page 190 - Negative battery terminal. Page 7285 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 2316 - Apply rubber lubricant to the inside diameter of hose ends, If desired. - Slip a new hose clamp over one end of the hose and push the hose onto the heater pipe with a twisting motion. - Repeat the hose and clamp installation procedure at the other end of the hose. - Tighten clamp screw to 1.7 Nm (15 in. lb.). 4. Engine coolant. - Use the coolant drained earlier only if it is uncontaminated. Discard contaminated coolant and add fresh 50/50 coolant and water mixture. Inspect - Be sure the installed hose(s) do not sag or rub against other components. Adjust or support the hose as necessary to correct. - Operate the engine and check the hose installation for leaks. - Tighten the hose clamp screw a bit at a time, if necessary, to stop a leak. - Check the coolant level after the engine has been warmed up and allowed to cool. Add coolant as required. Page 8635 - The split post guide clips with new solid post guide clips (Figure 2, Views A and B). The material in the new clip has been changed and the post redesigned. The material change is not evident, but provides additional strength in the clip hinge area. The new post is solid instead of split providing better fastening characteristics (Figure 2, View A). The purpose of the guide clips is to keep the glass parallel to the door frame when the glass is cycled. SERVICE PROCEDURE: 1. Remove the window glass. Follow the "Front Door Window Replacement" instructions in "Section 10A1-Door" of the applicable Service Manual. 2. Install new redesigned guide clips on the new glass. Glass P/N's 15960877-LH and 15960878-RH for non-export vehicles or P/N's 15962245-LH and 15962246-RH for export vehicles (RPO A26). - Align the clips with the holes in the glass and carefully snap together securely at each fastener location. The clips attach to the rear upper edge and front lower edge of the front door glass through holes in the glass (Figure 2, View B). 3. Remove three screws from the weatherstrip in the run assembly and remove the weatherstrip (Figure 1). 4. Install a new low friction run assembly weatherstrip, P/N 15960867-LH or 15960868-RH (Figure 1, Section A-A). Torque the fastening screws to 1.6 - 2.2 N-m (13 - 18 lbs.in.). Ensure the weatherstrip is properly seated in the door run channels. (Special care should be taken to ensure the weatherstrip below the door daylight opening is also properly seated). Apply silicone spray lubricant to the lower portion of the run assembly as indicated in illustration. 5. Install the new glass assembly (with new guide clips). Follow "Front Door Window Replacement" instructions in "Section 10A1-Doors" in the applicable Service Manual. 6. Check for proper window operation. Restraints - Passenger Presence System Information Seat Occupant Sensor: Technical Service Bulletins Restraints - Passenger Presence System Information INFORMATION Bulletin No.: 06-08-50-009F Date: December 23, 2010 Subject: Information on Passenger Presence Sensing System (PPS or PSS) Concerns With Custom Upholstery, Accessory Seat Heaters or Other Comfort Enhancing Devices Models: 2011 and Prior GM Passenger Cars and Trucks Equipped with Passenger Presence Sensing System Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 06-08-50-009E (Section 08 - Body and Accessories). Concerns About Safety and Alterations to the Front Passenger Seat Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE THE SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER THE SEAT COVERS OR SEAT-RELATED EQUIPMENT. ANY ALTERATIONS TO SEAT COVERS OR GM ACCESSORIES DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. The front passenger seat in many GM vehicles is equipped with a passenger sensing system that will turn off the right front passenger's frontal airbag under certain conditions, such as when an infant or child seat is present. In some vehicles, the passenger sensing system will also turn off the right front passenger's seat mounted side impact airbag. For the system to function properly, sensors are used in the seat to detect the presence of a properly-seated occupant. The passenger sensing system may not operate properly if the original seat trim is replaced (1) by non-GM covers, upholstery or trim, or (2) by GM covers, upholstery or trim designed for a different vehicle or (3) by GM covers, upholstery or trim that has been altered by a trim shop, or (4) if any object, such as an aftermarket seat heater or a comfort enhancing pad or device is installed under the seat fabric or between the occupant and the seat fabric. Aftermarket Seat Heaters, Custom Upholstery, and Comfort Enhancing Pads or Devices Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE ONLY SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT RELEASED AS GM ACCESSORIES FOR THAT VEHICLE. DO NOT USE ANY OTHER TYPE OF SEAT COVERS OR SEAT-RELATED EQUIPMENT, OR GM ACCESSORIES RELEASED FOR OTHER VEHICLE APPLICATIONS. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ACCESSORIES, INCLUDING ANY WARRANTY REPAIRS MADE NECESSARY BY SUCH USE. Many types of aftermarket accessories are available to customers, upfitting shops, and dealers. Some of these devices sit on top of, or are Velcro(R) strapped to the seat while others such as seat heaters are installed under the seat fabric. Additionally, seat covers made of leather or other materials may have different padding thickness installed that could prevent the Passenger Sensing System from functioning properly. Never alter the vehicle seats. Never add pads or other devices to the seat cushion, as this may interfere with the operation of the Passenger Sensing System and either prevent proper deployment of the passenger airbag or prevent proper suppression of the passenger air bag. Disclaimer Page 99 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 3889 Service Precautions A/C Coupler O-ring: Service Precautions WARNINGS: - Air conditioning systems contain Refrigerant-12. This is a special mixture which requires special handling procedures to avoid personal injury. - Always wear goggles and wrap a clean cloth around fittings, valves, and connections when performing work that involves opening the refrigerant system. - Always work in a well ventilated area and avoid breathing any refrigerant fumes. - Do not weld or steam clean on or near any vehicle-installed air conditioning lines or components. - If Refrigerant-12 should come in contact with any part of the body, flush the exposed area with water and immediately seek medical help. CAUTIONS: - All Refrigerant-12 drums are shipped with a heavy metal screw cap. The purpose of the cap is to protect the valve and safety plug from damage. It is good practice to replace the cap after each use of the drum. - If it is necessary to transport or carry any container of Refrigerant-12 in a vehicle, do not carry it in the passenger compartment. - See the manufacturer's guide-lines for storage, transportation and the maximum temperature to which the container can be exposed. - If the occasion ever arises to fill a small Refrigerant-12 drum from a large one, never fill the drum completely. Space should always be allowed above the liquid for expansion. Page 754 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 6654 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 5263 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Locations Engine Wiring, LH Side Oxygen Sensors - Silica Contamination Oxygen Sensor: Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Page 4571 Antilock Brakes Wiring Circuit Locations Engine Wiring, LH Side Page 6437 85-89 - 97104794 90-93 - 97104793 Adapter, Low Side: Part of Hose Asm. 0-rings: Receiver/dryer 85-91 - 94154048 92-93 - 94461700 Switch/pipe - 94461902 Suction hose: 85-86: 1.5L - 97104799; 1.6L - 97104800 90-93: 1.6L - 97104801; 1.8L - 97104803 B. General Information Several items affecting the performance and durability of the system should be considered: 1. Performance When performed properly, the retrofit from R-12 to R-134a will have minimal effect on the system's performance in most climatic conditions found in the United States and Canada. 2. Leakage Experience has shown that most leakage in an A/C system is due to leaks at the joints, or through a small leak in a hose, usually at the coupling. The R-134a molecules are smaller than R-12, and a small leak may result in a faster loss of refrigerant with R-134a. Because of this, it is very important to leak check all vehicles using the J 39400 leak detector, BEFORE the retrofit is performed, and repair any leaks found. "0" rings and hoses used in most GM vehicles are compatible with R-134a and do not need replacement during a retrofit. "0" rings or hoses installed in previous repairs may have been of non-compatible materials if GM parts were not used and will be more likely to deteriorate and leak than the original equipment materials. All "0" rings and hoses available through GMSP0 are compatible with R-134a. Remember that the normal policy is to replace the "0" rings whenever a joint is opened for any reason. 3. Desiccant You may have heard that the currently used desiccant in the accumulator is not compatible with R-134a. Extensive testing has shown that it is, in fact, suitable for use with R-134a, once it has been in service in an R-12 system. The accumulator in these models will not have to be changed during the retrofit procedure, unless the vehicle is more than 5 years old. Vehicles more than 5 years old should have the A/D replaced to add new desiccant for proper system drying. In the event that an accumulator/dryer (A/D) needs to be replaced on a retrofitted system in the future, only A/D's with XH-7 desiccant should be used. The service parts for the 1993 vehicles contain only XH-7 desiccant. The parts for the 1992 and older vehicles may contain either XH-5 or XH-7. Parts containing XH-7 can be identified (see Figure 1) by 1) an "A" printed on the top of the A/D; or 2) if there is a label on top of the A/D, there will be a square with an "A" inside; or 3) if there is a time code and date printed on top of the A/D just under the "Harrison" logo, the A/D contains XH-7. A/D's containing XH-5 can still be used on R-12 vehicles. 4. Improved Cooling Performance There have been service bulletins issued in the past with information improving the cooling performance of existing R-12 systems. These bulletins can also be used to improve the performance of retrofitted vehicles in high ambient temperature climates. 5. PAG or V5 Oil Compatibility Contrary to information published to date outside of General Motors, mineral oil and PAG or V5 oil ARE chemically compatible. The mineral oil left in the system after reclaiming the R-12 can remain in the system with no harmful effects. However, the mineral oil will not mix with the R-134a, and so will not circulate and perform its lubricating function. Testing has shown that most of the mineral oil will eventually collect in the Front Suspension - Squeaking Noise Suspension Spring ( Coil / Leaf ): Customer Interest Front Suspension - Squeaking Noise Group Ref.: 3 - Steering/Suspension Bulletin No.: 463302 Date: August, 1994 SUBJECT: FRONT SUSPENSION SQUEAK (INSTALL SERVICE KIT INSULATORS FOR COIL SPRINGS) MODELS: 1992-94 CHEVROLET AND GMC TRUCK S PICKUPS (TWO-WHEEL DRIVE ONLY) CONDITION: Some owners may comment that a squeaking noise can be heard emanating from the front suspension area of their vehicle. This condition may be duplicated by jouncing the vehicle body in the front while it is parked. If the condition is not verified in this manner, road test the vehicle. CAUSE: The usual cause of this squeak is the contact between the coil spring and the upper frame pocket or control arm. The insulators installed in production between the coil spring and the control arms might deteriorate allowing metal to metal contact to occur. CORRECTION: To fix this condition, a Service Kit (P/N 15989719) has been released containing two newly designed insulators with the upper insulator having a nylon insert. Placement of the nylon insert into the rubber insulator is from the top. The insulator, along with the insert, goes on the top of the coil spring while the other insulator without the insert goes on the bottom of the coil spring. Two service kits will be necessary if both front coil springs are causing a noise. Vehicles built after the VIN breakpoints have a newly designed frame pocket for the front coil spring. SERVICE PROCEDURES: Page 841 Rear Window Release & Defogger Components. Below Cigar Lighter Applicable to: 4Door Blazer & Jimmy Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Page 6131 Compressor Clutch: Testing and Inspection A/C Request Signal Circuit Circuit and Test Description: Turning "ON" the air conditioning supplies CKT 59 battery voltage to the A/C compressor clutch and to terminal "B8" of the ECM connector to increase and maintain idle speed. The ECM does not control the A/C compressor clutch, therefore, if A/C does not function, refer to the A/C section. If A/C is operating properly and idle speed dips too low when the A/C compressor turns "ON" or flares too high when the A/C compressor turns "OFF", check for an open CKT 59 to the ECM. If circuits are OK, it is a faulty ECM connector terminal "B8" or ECM. Page 1320 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Specifications Manifold Pressure/Vacuum Sensor: Specifications Voltage 3.6 to 5.2 V at 1000 to 2000 ft 3.5 to 5.1 V at 2000 to 3000 ft 3.3 to 5.0 V at 3000 to 4000 ft 3.2 to 4.8 V at 4000 to 5000 ft 3.0 to 4.6 V at 5000 to 6000 ft 2.9 to 4.5 V at 6000 to 7000 ft 2.8 to 4.3 V at 7000 to 8000 ft 2.6 to 4.2 V at 8000 to 9000 ft 2.5 to 4.0 V at 9000 to 10000 ft Specifications Idle Speed/Throttle Actuator - Electronic: Specifications Terminal Resistance Values Terminal Resistance Values Terminals "A" to "B" 40 to 80 ohms Terminals "C" to "D" 40 to 80 ohms Terminals "B" to "C" Infinite ohms Terminals "A" to "D" Infinite ohms Page 3716 accumulating at least 200 miles, call the appropriate marketing division technical assistance group. CORRECTION - CATEGORY B: Valve Train Chatter, Tick, or Click. For 1992 or 1993 vehicles equipped with a Romulus built (adjustable lash) LB4 (VIN Z 4.3L V6) engine, adjust valve lash. Bulletin 376107 provides information on this procedure and on how to identify Romulus-produced engines. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts are expected to be available on August 30, 1993. WARRANTY INFORMATION: Labor Operation: J0950 - Filter and Oil Replace Labor Time: Use published labor time. For 1992 LB4 vehicles: Labor Operation: T0500 - PROM replace Labor Time: 0.5 hours Specifications Mainshaft Bearing/Bushing: Specifications Front Bearing Cap Retaining Bolts ...................................................................................................... ................................................................... 15 ft. lbs. Page 8262 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Locations Fusible Link: Locations RH Front Side Of Engine. LH Front Of Engine Applicable to: 4.3L/V6-262 Turbo Engine Page 2289 RH Front Side Of Engine. RH Side Of Engine Block Applicable to: 1991-92 4.3L/V6-262 Engine, Except Bravada Page 6193 2. Remove rotor and bearing assembly retaining ring, using Snap Ring Pliers J 6083 (Fig. 9). 3. Install Pulley Rotor and Puller Guide 3 25031 to the front head (Fig. 15), and install 3 33020 Pulley Rotor and Bearing Puller down into the inner circle of slots in the rotor (Fig. 16). Turn the J 33020 puller clockwise in the slots to engage the puller tangs with the segments between the slots in the rotor. Page 3033 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Page 4579 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 6084 Blower Motor: Description and Operation BLOWER CONTROLS The Blower Motor Fan delivers air to the interior of the vehicle. Its speed is controlled by the Blower Switch and the Blower Resistors. When the Ignition Switch is in RUN, battery voltage is supplied to the Blower Switch through the HTR-A/C Fuse. With the Blower Switch in LO, voltage is supplied across both Blower Resistors and the Blower Motor. The Blower Motor runs at its slowest speed. With the Blower Switch in MED, one of the Blower Resistors is bypassed and the Blower Motor runs faster. When the Blower Switch is set to HI, battery voltage is supplied directly to the Blower Motor and the Blower Motor runs at its fastest speed. Speedometer - Registers When Vehicle is Stationary Vehicle Speed Sensor: Customer Interest Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. Page 6756 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Engine, A/T - Shift/Driveability Concerns/MIL ON Continuously Variable Transmission/Transaxle: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 7925 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 6423 Select and install the proper R-134a fittings (shown in Figure 4) from the chart below, based on how the ACR4 couplers will attach. Also, remember to check for proper hood clearance with the conversion fittings. Try the straight fittings first. The two-piece high side fitting is used when the existing fitting is screwed into the pipe fitting (some 1992, and nearly all 1993 models, use these fittings). Use the 90° elbow if the straight fitting does not allow the ACR4 couplers to connect. Fitting Type High Side Low Side Straight 52467941 52467943 Straight Two-piece 52467324 N/A 90° Elbow 52469054 52469055 The fittings should be installed as follows: a. Remove the caps from the R-12 fittings. Remove any dirt or grease from the port threads using the thread cleaning wire brush, J 41265. Inspect the fittings for thread damage. If any damage is found, use the port thread restorer (J 41266 low side, J 41267 high side) to repair the thread. For the two-piece fitting, remove the existing R-12 fitting and discard it. Use tool J 38704A (previously released, not part of the above kit) to remove the fitting. Make sure to hold the line securely to prevent damage when removing the existing fitting. If the fitting cannot be removed easily, use the saddle clamp valve listed below and seal the R-12 port and cap permanently. b. Install the selected fitting onto the existing R-12 fitting. Leave the valve core in the straight fittings, and remove the valve core when using the 90° fittings. If the valve cores need to be removed at a later time, they can be removed with the straight conversion fittings in place. On the low side straight fitting, use the J 34611-A tool to remove the core pin in the conversion fitting, then remove the core valve from the original R-12 fitting. Always recover the charge before valve core removal. Locations CMFI Assembly Page 6152 Compressor Clutch: Service and Repair With HR100T/HR110T Compressor Clutch Plate and Hub Assembly 4 POLE AND 6 POLE CLUTCH Remove or Disconnect 1. If compressor is on the vehicle, loosen compressor mounting brackets, disconnect the compressor drive belt and reposition the compressor for access, if necessary. If compressor has been removed from the vehicle, attach the compressor to Holding Fixture 3 25008-A and clamp the Holding Fixture in a vise (Fig. 5). - Compressor mounting holes are metric. Use proper metric bolts with holding fixture J 25008-A. 2. Keep the clutch hub from turning with the Clutch Hub Holding Tool J 33027-A, remove the shaft nut, using Thin Wall Socket J 9399 (Fig. 5). 3. Thread the Clutch Plate and Hub Assembly Remover J 33013-B, into the hub. Hold the body of the Remover with a wrench and turn the center screw into the Remover body to remove the Clutch Plate and Hub assembly (Fig. 6). 4. Remove the shaft key. Install or Connect Page 93 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 322 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7469 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 7335 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 7598 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Wheels - Sealing Leaking Cast Aluminum Wheels: All Technical Service Bulletins Wheels - Sealing Leaking Cast Aluminum Bulletin Number: 93-3-16 Reference Number: 393504 Publish Date: 7/93 Subject: LEAKING CAST ALUMINUM WHEELS (REPAIR WITH ADHESIVE SEALANT) Models Affected: 1985-1993 ALL MODELS Should a vehicle equipped with cast aluminum wheels exhibit a slow leak due to a porous condition existing in the wheel, the wheel can be repaired by using Dow Corning Silastic 732 RTV, p/n 1052366 or equivalent, as described in the following procedure: 1. Remove tire-wheel assembly from vehicle. 2. Locate leaking area by inflating tire to 40 psi and dipping tire-wheel assembly in water bath. 3. If air bubbles are observed, mark leak area and remove tire from wheel. 4. Scuff INSIDE rim surface at leak area with # 80 grit paper and clean area with general purpose cleaner, such as 3M # 08984. 5. Apply 1/8" thick layer of adhesive/sealant to leak area on INSIDE of rim and allow six hours of drying time. 6. Mount tire on wheel, pressurizing to 40 psi and check for leaks. NOTICE: Caution must be used when mounting the tire so as not to damage the sealer. 7. Adjust tire pressure to meet placard specification. 8. Balance tire-wheel assembly, using proper coated weights. 9. Water test wheel again. 10. Reinstall tire-wheel assembly on vehicle. Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation Number: E0420 Page 7592 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7273 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7330 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Connector C1 ECM Connector C1 Service and Repair Fuel Pressure Release: Service and Repair Fuel Supply System CMFI FUEL PRESSURE RELEASE PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure - Connect fuel pressure gauge to fuel pressure connection tap. Wrap a shop towel around fitting while connecting gauge to avoid spillage. - Install bleed hose into an approved container and open valve to bleed system pressure. Fuel connections are now safe for servicing. - Drain any fuel remaining in gauge into an approved container. Page 8119 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Instrument Panel - Upper Surface Reflection Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel - Upper Surface Reflection File In Section: 08 - Body and Accessories Bulletin No.: 99-08-49-006 Date: April, 1999 INFORMATION Subject: Cleaning of Upper Instrument Panel Surfaces Models: 1999 and Prior Passenger Cars and Light Duty Trucks Comments on a reflection of the upper instrument panel pad into the windshield, when driving in direct sunlight, may be received. This condition, sometimes referred to as a "veiling reflection", may be aggravated by the use of wax or silicone based products when cleaning the surface. Advise customers, technicians and new car prep or make ready personnel, that products containing wax or silicone should not be used to clean the top instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap or an equivalent, should be used whenever the top instrument panel pad needs cleaning. If a customer requests that a protectant type product be applied, ONLY USE THOSE THAT LEAVE A FLAT OR SATIN FINISH. Do NOT apply products that leave a glossy finish or those that Increase the shine level above the original production level. Page 3121 EGR Valve: Service and Repair Electronic Linear EGR Valve Replacement Linear EGR Valve Central MFI Linear EGR Valve REMOVAL - Disconnect electrical connector. - Remove valve to flange attaching bolts. - Remove Linear EGR valve and gasket. - Discard gasket. INSTALLATION - Install Linear EGR valve and a new gasket. - Install valve to flange attaching bolts. Tighten to 24 N-m (17 lb. ft.). - Connect electrical connector. - Use a bidirectional scanner to confirm that system is functional. Page 3378 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 8013 Page 48 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7477 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 1039 Oil Filter: Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 297 Symbol Identification Page 2726 Valve Clearance: Specifications Valve Arrangement All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E Page 8218 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 8110 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 3913 Fluid - A/T: Fluid Type Specifications 4L60 & 4L60-E Transmission Fluid Type ............................................................................................................................................ ............................................................... Dexron IIE 4L80-E / -EHD Transmission Lubricant Type ..................................................................................................................................... ............................................................... Dexron II E Page 8410 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 401 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 386 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 6383 being done. Important: During 1996, "oil-less" compressors began to be serviced with NO added oil. New part numbers will be issued, and both the box and the compressor will be clearly marked to indicate that no oil is present. If you receive one of these newer compressors, simply add the normal amount of oil to the system in Step 5 of the retrofit procedure (8 oz of PAG oil, or 9 oz of PAG oil with V5 compressor). These "oil-less" compressors are compatible with EITHER R12 or R-134a. Geo Models Compressors DO NOT HAVE TO BE REPLACED as part of the retrofit. New compressors are shipped with enough oil to accommodate the entire A/C system. Do not add additional PAG oil to the system it the compressor is being replaced. 1985-88 Nova, 1989-93 Prizm (S) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Loosen evaporator to compressor (suction) pipe (to be reinstalled) c. 1985-92 only: Loosen compressor to condenser (compressor discharge) pipe (to be reinstalled). d. 1985-88 only: Service Valve & Extension Housing on compressor (to be installed). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. 1985-88 only: Service Valve & Extension Housing on compressor using new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe 0-ring. e. 1985-92 Compressor to condenser (discharge) hose 0-ring. f. Receiver/dryer and 0-rings. R-134a amount: 85-92 - 650 grams (1.43 lb) 93 - 700 grams (1.54 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-88 - 94855761 89-93 - 94855762 Adapter Fittings: Low Side - 94855760 High Side - 94855759 0-Rings: 85-88 Compressor - Small 0-rings (6 required) - 94857336 - Large 0-ring - 94857337 85-93 Receiver/Dryer (2) - 94845949 Oil Pressure Gauge - Incorrect or Erratic Readings Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Incorrect or Erratic Readings Number: 93-57-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268304 ASE No.: A1, A8 Subject: INCORRECT OR ERRATIC OIL PRESSURE READINGS Model and Year: 1990-93 ALL LIGHT DUTY TRUCKS Owners of some 1990 through 1993 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. Service Procedure: Check for normal causes of high oil pressure gauge readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure below. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. connect the negative battery cable. Parts Information: Page 95 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 5945 II. OVER TORQUING OF WHEEL NUTS: 1. A TORQUE WRENCH MUST BE USED to insure that the wheel nuts are tightened to specification. This should be done in two steps using the star pattern. First, snug the nuts down by hand. Then, using the star pattern and a torque wrench, tighten the wheel nuts to about half the final torque. Finally, tighten the wheel nuts to specification using the star pattern and a torque wrench. 2. NEVER use lubricants or penetrating fluids on wheel studs, nuts, or mounting surfaces, as this can raise the actual torque on the nut without a corresponding torque reading on the wrench. Wheel nuts, studs, and mounting surfaces must be clean and dry. Page 1689 Connecting Rod: Specifications Connecting Rod cap Nuts 45 ft.lb Page 7405 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 2749 Coolant Temperature Sensor/Switch (For Computer): Description and Operation ECT Circuit (Typical) Engine Coolant Temperature Sensor PURPOSE Engine Coolant Temperature (ECT) Sensor is used to control: Exhaust Gas Recirculation (EGR) - Fuel delivery - Idle Air Control (IAC) - Ignition Control (IC) - Torque Converter Clutch (TCC) OPERATION The ECT sensor is a thermistor that is located in the engine coolant flow. Low coolant temperature sensor produces a high resistance (100,000 ohms at -40°C/-40°F). High coolant temperature, produces a low resistance (70 ohms at 130°C/266°F). The control module sends a 5.0 volt signal to the ECT through a resistor in the control module and measures the voltage. The voltage will be high when the engine is cold and low when the engine is hot. Engine coolant temperature affects most systems controlled by the control module. The control module uses information from the ECT to calculate spark advance as follows: Cold engine results in more spark advance. - Hot engine results in less spark advance. Page 5411 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 1643 1. Disconnect battery. 2. Drain coolant. 3. Remove fan shroud. 4. Remove accessory drive belt. 5. Remove fan. 6. Remove the water pump. 7. Remove crankshaft pulley and harmonic balancer. 8. Remove transmission torque converter cover. Let it lie on top of exhaust crossover pipe. 9. Drop the oil pan by leaving the rear two nuts on the crankshaft seal studs about 1/4 inch from tight. The two studs will stabilize the oil pan and the oil will not have to be drained. 10. Remove the front cover. 11. It is recommended that the engine be turned over by hand so the crankshaft and camshaft sprocket timing marks are dot to dot. 12. Loosen the small diameter balance shaft gear bolt. This is the driven gear and has a TORX drive bolt. 13. Remove the camshaft sprocket by taking off the lock nut first, then the two bolts. 14. Remove the large diameter balance shaft (drive) gear. 15. Remove the small diameter balance shaft driven gear. 16. Clean all sealing surfaces, removing all old gasket material. Installation of new matched set balance shaft gears: 1. Install driven gear (small diameter gear) and bolt finger tight. 2. Install and align drive gear dot to dot with timing mark of the driven gear. 3. Install drive gear stud to 16 Nm (12 lb.ft.) to ensure the shoulder of the stud is below the counter bore in the gear. 4. Install camshaft sprocket and chain. Ensure their timing is correct. If the camshaft and crankshaft have not been disturbed, the crankshaft and camshaft sprockets should be dot to dot. 5. Install the camshaft sprocket nut and bolts. Torque to 28 Nm (21 lb.ft.). 6. Torque driven balance shaft gear bolt to 20 Nm (15 lb.ft.) plus an additional 35° using a J 3660 degree meter, torque driver. 7. At this point, the gear change is complete. Follow the removal steps in reverse order to install the remaining components. Consult the service manual for torque specifications. CORRECTION II. The following steps should be followed to diagnose the detonation type rattle noise which occurs between 2000 - 2500 RPM under load (condition II): 1. Ensure the ESC (Electronic Spark Control) system is working properly. Refer to the ELECTRONIC SPARK CONTROL section of the LIGHT DUTY TRUCK FUEL AND EMISSIONS section of the service manual. This section includes an "ELECTRONIC SPARK CONTROL SYSTEM CHECK" with a fault tree for the 4.3L CPI engine. 2. Operate the vehicle with premium fuel. If the noise is eliminated, the noise is not coming from the balance shaft rear needle bearing. Refer to the DRIVEABILITY SYMPTOMS section of the LIGHT DUTY TRUCK FUEL AND EMISSIONS service manual. BRAVADA ONLY: Refer to Bravada service manual section 6E. 3. If the ESC system is functioning properly and the noise is still audible using premium fuel, the source of the noise is most probably the rear Page 5440 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 7249 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 2004 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Page 6766 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Manual Steering Gear - Saginaw Recirculation Ball Steering Gear: Service and Repair Manual Steering Gear - Saginaw Recirculation Ball Removal/Installation 1. On models equipped with power steering, disconnect pressure and return hoses from steering gear housing, then plug hose ends and gear housing ports to prevent entry of dirt. 2. On all models, disconnect battery ground cable and remove coupling shield if so equipped. 3. Remove retaining nuts, lock washers and bolts at steering coupling to steering shaft flange. 4. Remove pitman arm nut and washer from pitman shaft and mark relation of arm position to shaft, then remove pitman arm using a puller. 5. On turbocharged models, raise and support vehicle. 6. Remove charge air cooler radiator. 7. Lower vehicle, then remove intermediate shaft assembly at steering gear. 8. Remove attaching bolt and nut to pot joint coupling. Ensure alignment marks line up. 9. On all models, remove screws securing steering gear to frame and remove gear from vehicle. 10. Reverse procedure to install. Disassembly Fig. 4 Steering gear assembly 1. Referring to Fig. 4, loosen adjusting screw locknut and remove housing side cover by removing adjusting screw. 2. Loosen locknut and back off worm bearing adjuster several turns, then remove housing end cover and gasket. 3. Remove lower thrust bearing, steering shaft and upper bearing from housing. 4. Remove ball return guide clamps and guides from ball nut. Turn ball nut over and remove ball nut from steering shaft worm. Inspection 1. Clean and inspect all ball and roller bearings and races, including race in housing. 2. Inspect pitman shaft bushings in gear housing and end cover. If bushings are worn excessively, replace. 3. It is advisable to replace pitman shaft grease seal in housing to avoid possible leakage of lubricant. Seal must be installed with feather edge toward inside of housing. 4. Inspect pitman shaft for wear or pits in bearing races, which would require replacement of shaft. 5. Check shaft for straightness. 6. Inspect teeth of ball nut and pitman shaft. If scored or excessively worn it is advisable to replace both parts to insure proper mating of teeth. 7. Check serration of pitman shaft; if twisted replace shaft. 8. Check fit of pitman shaft adjusting screw and shim in slot in end of pitman shaft. With shim in place, screw head must be free to turn in slot with zero to .002 inch end play. If endplay is excessive, selectively fit a new shim, which are available in four different thicknesses. Assembly Lubricate all seals, bushings, bearings and gears with multi-purpose gear lube prior to installation. 1. Position ball nut over worm shaft so that deep side of teeth will be toward side cover when installed in gear housing. Page 3616 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Page 8113 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 7407 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: Customer Interest Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Engine - High Oil Pressure Reading at Start-Up Oil Pressure Gauge: All Technical Service Bulletins Engine - High Oil Pressure Reading at Start-Up Number: 93-60-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268306 ASE No.: A1, A8 Subject: HIGH OIL PRESSURE READING AT START-UP Model and Year: 1992-93 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L, AND 5.7L ENGINES Some 1992 and 1993 Chevrolet Light Duty Trucks with oil pressure gauges built after 6/15/92 may exhibit high oil pressure readings at start up, especially when cold. Engines produced after 6/15/92 were built with an enhanced oil pump capable of producing approximately 10 psi more pressure than the previous pump. This may cause the gauge to temporarily read as high as 60 psi during start up. The length of time the oil pressure stays high will depend on oil viscosity, engine temperature, and ambient temperature. This condition will not cause any ill effects on the engine or gauge and unless there are other symptoms to indicate an oil pressure or gauge problem such as very low pressure after warm up, rapid fluctuation, engine noise etc. no repairs should be attempted. Replacing the oil pump or gauge system parts will not be effective. Build date of the engine can be verified by the engine code. The location of this code is illustrated in section OA of the appropriate service manual. The engine code is 8 positions long with an alpha plant designator in the first position, followed in the next four positions by the month and day; for example T0615xxx would indicate that this engine was built in Tonawanda on June 15th and, therefore, has the enhanced oil pump. The plant code is insignificant because all 4.3L, 5.0L, and 5.7L plants began using the enhanced oil pump on the same day. Page 281 RH Front Side Of Engine. RH Side Of Engine Block Applicable to: 1991-92 4.3L/V6-262 Engine, Except Bravada Page 5609 Fig. 1 Troubleshooting power steering system Page 1221 procedures and short-cutting refrigerant recycling times. Use the following procedure for testing and correcting air contamination in your A/C service equipment. 1. Make certain that the ACR4 equipment has not been used for at least 12 hours. It is recommended that the equipment be left in an area where the temperature will remain constant overnight to allow the temperature of the refrigerant in the tank to stabilize. 2. Record the surrounding air temperature next to the ACR4 refrigerant tank. Important: A major assumption is that the ambient air temperature next to the tank represents the refrigerant temperature in the tank. Failure to take care in measuring the temperature could result in unnecessary work. 3. Close both liquid (blue) and vapor (red) valves on the ACR4 tank. 4. Disconnect low side (blue) service hose from the back of the ACR4. 5. Slowly disconnect the tank vapor hose (red) from the back of the ACR4 and connect it to the low side service port. 6. Open the vapor (red) valve on the tank and record the tank pressure on the low side gage. 7. Restore hoses to the original position. 8. Referring to the Table, find the ambient temperature measured in Step 2. Compare the pressure reading from Step 6 to the "maximum allowable pressure". If the pressure reading from Step 6 is less than the "maximum allowable pressure", no further action is necessary. Important: The closer the tank pressure is to the desired tank pressure, the better the A/C system will perform. 9. If the pressure reading from Step 6 exceeds the maximum allowable pressure from the Table, open both tank valves and operate the ACR4 through 4 or 5 evacuation cycles. This will activate the automatic air purge to lower the tank pressure. Important: Station should not be connected to vehicle. 10. Repeat the tank pressure checking procedure the next day to determine if the pressure has been reduced to acceptable levels. If the tank pressure has been reduced but is not acceptable, cycle with ACR4 through more evacuation cycles and recheck the next day. Continue process until acceptable pressure is obtained. If the tank pressure is not reduced through the evacuation cycling, then Kent-Moore should be contacted at 1-800-345-2233. Specifications Engine Oil Pressure: Specifications Vin Z, W, Oil Pressures Vin Z, W, Oil Pressures Normal Oil Pressure Minimum Pressures 6 psi at 1000 rpm 18 psi at 2000 rpm 24 psi at 4000 rpm Page 1883 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 1382 1. The tire must be in the relaxed position when the repair unit is installed (Do not spread the beads excessively). Two-Piece Plug and Repair Units 1. If applicable, install the repair unit so that the alignment is correct. 2. Center the repair unit over the injury and stitch down thoroughly with the stitching tool, working from the center out. 3. Being careful not to stretch the plug material, cut the plug flush with the outer tread. Combination Repair/Plug Units 1. Pull the plug through the injury until the repair just reaches the liner. Stitch down thoroughly. 2. Follow the repair material manufacturer's recommendations for further installation instructions. 2. Consult your repair material supplier for the proper stitching tool. Safety Cage Restraints - Passenger Presence System Information Seat Occupant Sensor: Technical Service Bulletins Restraints - Passenger Presence System Information INFORMATION Bulletin No.: 06-08-50-009F Date: December 23, 2010 Subject: Information on Passenger Presence Sensing System (PPS or PSS) Concerns With Custom Upholstery, Accessory Seat Heaters or Other Comfort Enhancing Devices Models: 2011 and Prior GM Passenger Cars and Trucks Equipped with Passenger Presence Sensing System Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 06-08-50-009E (Section 08 - Body and Accessories). Concerns About Safety and Alterations to the Front Passenger Seat Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE THE SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER THE SEAT COVERS OR SEAT-RELATED EQUIPMENT. ANY ALTERATIONS TO SEAT COVERS OR GM ACCESSORIES DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. The front passenger seat in many GM vehicles is equipped with a passenger sensing system that will turn off the right front passenger's frontal airbag under certain conditions, such as when an infant or child seat is present. In some vehicles, the passenger sensing system will also turn off the right front passenger's seat mounted side impact airbag. For the system to function properly, sensors are used in the seat to detect the presence of a properly-seated occupant. The passenger sensing system may not operate properly if the original seat trim is replaced (1) by non-GM covers, upholstery or trim, or (2) by GM covers, upholstery or trim designed for a different vehicle or (3) by GM covers, upholstery or trim that has been altered by a trim shop, or (4) if any object, such as an aftermarket seat heater or a comfort enhancing pad or device is installed under the seat fabric or between the occupant and the seat fabric. Aftermarket Seat Heaters, Custom Upholstery, and Comfort Enhancing Pads or Devices Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE ONLY SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT RELEASED AS GM ACCESSORIES FOR THAT VEHICLE. DO NOT USE ANY OTHER TYPE OF SEAT COVERS OR SEAT-RELATED EQUIPMENT, OR GM ACCESSORIES RELEASED FOR OTHER VEHICLE APPLICATIONS. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ACCESSORIES, INCLUDING ANY WARRANTY REPAIRS MADE NECESSARY BY SUCH USE. Many types of aftermarket accessories are available to customers, upfitting shops, and dealers. Some of these devices sit on top of, or are Velcro(R) strapped to the seat while others such as seat heaters are installed under the seat fabric. Additionally, seat covers made of leather or other materials may have different padding thickness installed that could prevent the Passenger Sensing System from functioning properly. Never alter the vehicle seats. Never add pads or other devices to the seat cushion, as this may interfere with the operation of the Passenger Sensing System and either prevent proper deployment of the passenger airbag or prevent proper suppression of the passenger air bag. Disclaimer Page 1570 sure the retainer cup is tree from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. Important: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Except for the N9O 4X4 wheel used on T trucks, all light truck aluminum wheels will accept either "AW" series or "MO" series clip-on coated weights on both the inside and outside rim flanges. The N9O T truck wheel will accept "AW" series weights on the inside rim flange only. The outside rim flange is not designed to accept a clip-on weight. If such a weight installation is attempted, a poor fit will result, and the weight may fall off and/or cause cosmetic damage to the rim flange. This wheel can be 1) static balanced by clipping all the weight on the inside rim flange (as is done in the assembly plant), or 2) dynamic balanced by clipping a weight on the inside flange and using an adhesive weight near the outside flange. The charts show "AW" and "MC" balance weight usage. These original equipment coated weights are available at competitive prices through the GM Dealer Equipment program. Page 7935 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Locations Engine Coolant Temperature (ECT) W Page 8266 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Diagram Information and Instructions Hazard Warning Flasher: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 7790 Door Switch: Locations Door Jamb Switch, LH Front In LH A-Pillar Page 8226 Hazard Warning Flasher: Description and Operation Voltage is applied at all times, through the STOP-HAZ Fuse and the Hazard Flasher to the normally open contact of the Hazard Switch in the Turn Signal Switch Assembly. With the Hazard Switch in HAZARD FLASH, voltage is applied to both Front and Rear Turn Lamps. All of the Turn Lamps and Turn Indicators flash on and off. The Front Marker Lamps flash in HAZARD FLASH just as they did in TURN RIGHT and TURN LEFT. If the Light Switch is in OFF, they flash on when the Hazard Lamps are on. If the Light Switch is in either PARK or HEAD, they flash on when the Hazard Lamps are off and off when the Hazard Lamps are on. In HAZARD, the circuit is always open, and the Hazard Flasher controls the Lamps. Page 145 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 5497 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 6552 Important: Before using the tester and the diagnostic chart, the following two steps must be performed. 1. Verify that the keyless entry transmitter is the correct model for the vehicle remote system. An incorrect model transmitter may pass this test, but may not activate the vehicle remote system. The correct transmitter can usually be identified by part number. 2. Ensure that the transmitter is synchronized with the vehicle (if applicable). Refer to Transmitter Synchronization in the appropriate Service Manual. Recall 93V008000: Cooling Fan Replacement Fan Blade: All Technical Service Bulletins Recall 93V008000: Cooling Fan Replacement THE ENGINE COOLING FAN BLADES BREAK AS A RESULT OF FATIGUE AND/OR VEHICLE INDUCED STRESS. IF THE BLADE BREAKAGE OCCURS WHILE THE HOOD IS OPEN, A PERSON WORKING UNDER THE HOOD OR IN THE VICINITY OF THE VEHICLE COULD BE STRUCK AND INJURED BY THE BLADE SEGMENT. INSTALL A NEWLY DESIGNED FAN ASSEMBLY. SYSTEM: ENGINE. VEHICLE DESCRIPTION: LIGHT TRUCKS WITH 2.5 L ENGINES WITHOUT AIR CONDITIONING. 1989 CHEVROLET TRUCK S10 1989 GMC S15 1990 CHEVROLET TRUCK S10 1990 GMC S15 1991 CHEVROLET TRUCK S10 1991 GMC S15 1992 CHEVROLET TRUCK S10 1992 GMC S15 Page 432 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 149 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 6613 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 3623 Spark Plug: Specifications Spark Plugs 22 ft.lb Page 2509 Intake Air Temperature Sensor: Description and Operation Intake Air Temperature Sensor PURPOSE The Intake Air Temperature (IAT) sensor is a thermistor and converts the resistance of the sensor to degrees. IAT is used by the control module to adjust fuel delivery and spark timing according to oncoming air density. OPERATION The control module applies a voltage (4-6 volts) signal to the IAT sensor through a resistor within the PCM and measures the voltage. By measuring the voltage, the PCM can determine IAT. Low intake air temperature produces high resistance (100,000 ohms at -40°C/-40°F) and high voltage. High intake air temperature produces a low resistance (70 ohms at 130°C/266°F) and low voltage. Specifications Shift Solenoid: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Page 2979 Throttle Position Sensor: Description and Operation TP Sensor Throttle Position Sensor (TPS) PURPOSE The Throttle Position Sensor (TPS) is a non-adjustable potentiometer that senses throttle angle and relays the information to the control module. This input to the control module is used to control the fuel system and most of the control module outputs. CONSTRUCTION The TPS has internally three circuits. One to ground, the other from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage . As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). OPERATION As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation movement to the TP sensor. A potentiometer (variable resistor) within the Throttle Position (TP) sensor assembly changes its resistance in proportion to throttle movement. If the TP sensor senses a Wide Open Throttle (WOT) a voltage signal indicating this condition is sent to the control module. The control module then increases the injector base pulse width, permitting increased fuel flow. LOCATION The non-adjustable Throttle Position (TP) sensor, is mounted on the side of the throttle body opposite the throttle lever assembly. Page 8598 Rear Door Power Window Page 6688 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Spark Plugs - Revised Spark Plug: Technical Service Bulletins Spark Plugs - Revised Number: 93-03-6D Section: 6D Date: AUGUST 1992 Corporate Bulletin No.: 166001R ASE No.: Al, A6, A8 Subject: NEW DESIGN SPARK PLUGS Model and Yew: 1991-93 ALL PASSENGER CARS AND TRUCKS WITH GASOLINE ENGINES THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO., 91-234A-OB, DATED JULY 1992. THE 1992 AND 1993 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 91-234A-OB SHOULD BE DISCARDED. In 1991 GM introduced a new design spark plug for use in all trucks equipped with gas engines. These new design spark plugs have a ceramic insulator which is approximately 1/8 inch longer than the insulator used in previous model years. The longer length spark plugs, which conform to S.A.E. and I.S.O. Engineering guidelines, magnify the problem of cracked insulators because currently, most spark plug sockets are not of sufficient length to properly engage the shell hex. If the spark plug shell hex is not fully engaged in the spark plug socket wrench, the socket may cock at an angle and cause insulator cracking and/or breakage during plug installation or removal. When servicing these new design spark plugs, make sure that the spark plug socket being used is deep enough to accommodate the longer length insulator. The spark plug socket wrench should conform to the proposed S.A.E. and I.S.O. world standards for spark plug socket wrenches. Spark plug socket wrenches that conform to these standards are designed to accept the lengthened spark plugs and allow full engagement of the hex nut on the shell of the spark plug. Use of a spark plug socket which is NOT deep enough may result in the ceramic insulator becoming cracked above the spark plug shell. Note: SOME CRACKS IN THE INSULATOR M" NOT BE VISIBLE. SUCH CRACKS MAY LATER CAUSE A SPARK PLUG TO MISFIRE. SPARK PLUG MISFIRES ARE OFTEN MISDIAGNOSED AS A SLIPPING TRANSMISSION, DEFECTIVE TORQUE CONVERTER CLUTCH, ENGINE IMBALANCE, OR MALFUNCTIONING FUEL SYSTEM. To prevent insulator damage, it is recommended that the proper spark plug socket wrench be used when removing or replacing spark plugs. One such spark plug socket is the Kent-Moore J-39358 spark plug socket. The tool is available from Kent-Moore. For ordering information call 1 -800-345-2233 or write: Kent-Moore SPX Corporation 39784 Little Mack Roseville, MI 48066-2298 Fax: 313-774-9870 Page 7947 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Page 223 Ignition Control Module: Description and Operation PURPOSE The distributor reference signal provides the ECM with both engine RPM and crankshaft position information. This enables the ECM to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the ECM receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the ECM will not operate the injector. Specifications Heater Hose: Specifications Heater Hose Clamp Screw .................................................................................................................. ................................................... 1.7 Nm (15 in. lb.). Page 3723 PROM - Programmable Read Only Memory: Application and ID PROM/MEMCAL Identification Marks File In Section: 6E - Engine Fuel & Emission Bulletin No.: 44-65-01 Date: October, 1994 Subject: New PROM/MEMCAL Identification Markings Models: 1995 and Prior Passenger Cars and Trucks Note: For the purposes of this document, the terms PROM and MEMCAL will be used interchangeably. To simplify identification of service PROMs. a new external marking format will be implemented. Parts manufactured after Sept. 1994 will feature these new markings. This change will place the full 8-digit service part number on the PROM, in place of the old 4-digit "EXTERNAL ID" number. In the past, parts and service personnel could not identify a PROM without using a cross-reference table that matched external IDs and service numbers. In the future, the cross-reference table will not be required for PROMs; parts will be ordered directly from the number appearing on the PROM. However, the label will retain the broadcast code alpha characters to allow continued use of cross-reference charts, if so desired. Old Marking Format: New Marking Format: ^ Ordering the above PROM from the old marking format would require using a cross-reference chart to determine a service part number, based on the BROAD CAST CODE and EXTERNAL ID NUMBERS. ^ To order from the new format, simply combine the 2nd and 3rd lines to form an 8-digit part number that can be directly ordered from SPO (number 16134624 in the above example). As these changes are phased into the parts inventory, it should be noted that dealers will continue to see parts with both formats for some time in the future. This is because: ^ Millions of vehicles have already been built with the old format. ^ SPO has existing stock of MEMCALs and PROMs with the old format. ^ PROMS with 7-digit part numbers (representing less than 10% of current part numbers) will continue to use the old format. The 7-digit part numbers are easily identified because they always begin with "122xxxx". Due to manufacturing processes, more than one 8-digit part number may appear on a MEMCAL. In this event, service personnel should use the label on the exterior cover of the MEMCAL assembly. To avoid confusion, only the service label will include the BROAD CAST CODE, consisting of letter characters (I.E., ARCL). Page 6228 Installing The Drive Plate - Install J 9401-A on the threaded end of the shaft. - Back off J 9401-A body to allow the center screw to be threaded against the end of the compressor shaft (39). - Hold the center screw with a wrench and tighten the hex portion of J 9401-A body while pressing the hub onto the shaft (39). After tightening the body several turns, remove J 9401-A and check that the shaft key (36) is properly in place in the keyway. - Air gap between contact surfaces of the clutch plate and hub assembly (2) and the pulley (6) should be 0.56-1.34 mm (0.022-0.057 inch). - Remove J 9401-A. Inspect - Position of the shaft (39) (even with or slightly above the clutch hub). 3. Shaft nut (1). - Use J 25030-A to hold the clutch plate and hub assembly (2). Tighten Shaft nut (1) to 27 N.m (20 ft.lbs.) with J 9399-A. - Hand spin the pulley (6) to check for free rotation. Page 2557 Throttle Position Sensor: Adjustments N/A: TPS is not adjustable on this engine. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Page 8120 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Page 2697 Spark Plug Wire Routing 4.3W Page 5818 Light Duty truck tire rotation recommendations are pictured on the following page. Rotation Guidelines for Tires used on Light Duty Trucks: Tires used on Pickups, Vans and Utility vehicles should be rotated at the first 6,000 miles for Schedule 1 or 7,500 miles for Schedule 2 and then every 15,000 miles thereafter. NOTE: Earlier rotation may be required should irregular wear pafterns develop due to harsh service use - the following rotation patterns are recommended for the various vehicle types and tire combinations. Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks utilize a warning light on the instrument panel in place of the conventional dash indicating gauge to warn the driver when the oil pressure is dangerously low. The warning light is wired in series with the ignition switch and the engine unit-which is an oil pressure switch. The oil pressure switch contains a diaphragm and a set of contacts. When the ignition switch is turned on, the warning light circuit is energized and the circuit is completed through the closed contacts in the pressure switch. When the engine is started, build-up of oil pressure compresses the diaphragm, opening the contacts, thereby breaking the circuit causing the light to go out. Page 6768 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 8165 Turn And Hazard Lamp Flashers Page 5407 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Page 1895 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. TCC Solenoid Rear Of Engine Page 6167 4. Remove the forcing tip on J 33013-B clutch plate and hub assembly installer-remover center screw and reverse the body direction on the center screw. Removing Pulley Rotor And Bearing Assembly 5. Install the clutch plate and hub installer-remover J 33013-B with bearing. The body of the J 33013-B installer-remover should be backed off sufficiently to allow the center screw to be threaded onto the end of the compressor shaft. 6. Hold the center screw with a wrench. Tighten the hex portion of the installer-remover J 33013-B body to press the hub onto the shaft. Tighten the body several turns, remove the installer and check to see that the shaft key is still in place in the keyway before installing the clutch plate and hub assembly to its final position. The air gap between frictional surfaces of the clutch plate and clutch rotor should be 0.50-0.76mm (0.020-0.030"). NOTICE: If the center screw is threaded fully onto the end of the compressor shaft. or if the body of the installer is held and the center screw is rotated, the key will wedge and will break the clutch hub. 7. Remove installer J 33013-B, check for proper positioning of the shaft key (even or slightly above the clutch hub). 8. Spin the pulley rotor by hand to see that the rotor is not rubbing the clutch drive plate. Clutch Rotor and/or Bearing Remove or Disconnect 1. Remove the clutch plate and hub assembly. Engine - High Oil Pressure Reading at Start-Up Oil Pressure Gauge: Customer Interest Engine - High Oil Pressure Reading at Start-Up Number: 93-60-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268306 ASE No.: A1, A8 Subject: HIGH OIL PRESSURE READING AT START-UP Model and Year: 1992-93 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L, AND 5.7L ENGINES Some 1992 and 1993 Chevrolet Light Duty Trucks with oil pressure gauges built after 6/15/92 may exhibit high oil pressure readings at start up, especially when cold. Engines produced after 6/15/92 were built with an enhanced oil pump capable of producing approximately 10 psi more pressure than the previous pump. This may cause the gauge to temporarily read as high as 60 psi during start up. The length of time the oil pressure stays high will depend on oil viscosity, engine temperature, and ambient temperature. This condition will not cause any ill effects on the engine or gauge and unless there are other symptoms to indicate an oil pressure or gauge problem such as very low pressure after warm up, rapid fluctuation, engine noise etc. no repairs should be attempted. Replacing the oil pump or gauge system parts will not be effective. Build date of the engine can be verified by the engine code. The location of this code is illustrated in section OA of the appropriate service manual. The engine code is 8 positions long with an alpha plant designator in the first position, followed in the next four positions by the month and day; for example T0615xxx would indicate that this engine was built in Tonawanda on June 15th and, therefore, has the enhanced oil pump. The plant code is insignificant because all 4.3L, 5.0L, and 5.7L plants began using the enhanced oil pump on the same day. Page 4652 Brake Caliper: Fundamentals and Basics Installation Notes WHEN INSTALLING CALIPERS AND PADS, REMEMBER... - Clean and lubricate caliper slide joint/pins with high temperature silicone grease: Unlike drum brakes, disc brakes do not utilize a spring to withdraw the pads/linings when the brake pedal is released. Disc brakes rely on the elasticity of the piston seals, and the unrestricted movement of the caliper slide assemblies to release the brakes. If the slide joints/pins are not cleaned and lubricated properly the disc brake linings will drag upon the release of the brake pedal. This will result in overheated brakes and premature brake wear. Disc Brake Mechanical Force Diagram NOTE: Floating calipers require free and unrestricted movement on the caliper mounting. Floating or sliding calipers have pistons only on one side of the rotor. The first part of the piston's travel forces the inner pad against the rotor, then further travel forces the movable part of the caliper to pull the outer pad against the rotor. High temperature silicone lubricant must be used. Low temperature grease can melt and contaminate the pads and rotors, or can bake into a very hard substance which binds the slides. Petroleum based grease can cause the slide boots to soften and swell. Work on one side at a time. If you forget how to reassemble the parts you can always use the other side as a model. Anti-squeal Coating - Apply an anti-squeal coating to the back side of the pads/linings. This coatings acts as an insulator to dampen high frequency vibrations that are generated during normal braking. These compounds are highly effective in preventing brake squeal. - Many professional repair shops recommend always rebuilding or replacing the calipers when replacing the brake linings, because: When the pistons are forced back into the calipers, the piston seals are dragged across any corrosion or abrasives that may be deposited on the inside of the caliper. Damage to the seals may not be initially evident. As the new brake linings begin to wear, the piston is gradually withdrawn from the caliper. Page 7776 Dashboard / Instrument Panel: Service and Repair Fig. 23 Lamp Switch Removal & Installation Fig. 24 Instrument Panel Components Page 7342 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Page 7032 Door edge guards Bumper filler panel, Frt./Rr. Front side marker lamps *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary G VANS Wiper arms Cowl vent grille Grille and headlamp bezels Front bumper filler panel Antenna Side view mirrors Side marker lamps Tail lamps Door edge guards Wheel opening moldings *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary Swing out windows/seals WARRANTY INFORMATION For vehicles repaired under warranty. and for customer satisfaction. use: Labor Op (Labor Operations include mix time) A6100 Refinish the entire exterior body surface ABOVE THE BODY SIDE MOLDING AND INSERT COLOR on two tone vehicles if equipped. A6101 Refinish the entire exterior body surface INSERT COLOR only. A61O2 Refinish the PICKUP BOX LOAD FLOOR AND INNER FENDERS when applicable. A61O3 On units with an insert color, included is the entire exterior body surface ABOVE THE BREAKLINE. (If the insert color and the entire body surface above the break-line requires refinishing, use A6100). Page 8421 Front Park And Marker Lamps Page 3885 Diagram Information and Instructions Brake Lamp: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 820 Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Page 1833 1992 LB4 VIN Z For vehicles with "cold knock" only. For vehicles with "cold knock" having previously installed detonation field fix PROM - OR For vehicles with "cold knock" and detonation For 1991-93 model year L05 and L19, 1991 and 1993 LB4 engines, two actions have been found to show a high probability of success incuring short duration cold knock (Category A). General Motors suggests performing the following steps. NOTE: These steps are only applicable to short duration cold knock, and will not eliminate a knock occurring under load. Neither will these actions eliminate a knock lasting more than 10 seconds, nor a knock occurring in a hot or warm engine. Step 1: Install a check valve oil filter Original Filter Install PF35 AC PF1218 PF51 AC PF52 Step 2: Change the oil; use a synthetic oil meeting the API Service SG or SG/CE standard. NOTE: This action is only required once; conventional (non-synthetic) API Service SG or SG/CE oil may be reinstalled at the next oil change. If an LB4 (VIN Z 4.3L V6) or an L05 (VIN K 5.7L V8) continues to exhibit short duration cold knock after performing steps one and two and Diagram Information and Instructions Cruise Control Switch: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 380 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 3737 [140] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [141] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [142] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [143] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [144] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [145] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [146] PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [147] PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [148] PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [149] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [150] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). Page 6221 Compressor Clutch Hub: Specifications With HR100T/HR110T Compressor Clutch Plate and Hub to Rotor ................................................................................................................................................ 0.5-0.76 mm (0.020-0.030") Page 6972 1). Record this measurement for reassemble purposes. This measurement will give the combined pinion bearing and seal pre-load. Also record the number of exposed threads beyond the flange nut on the pinion flange nut. 5. Remove the pinion flange nut and washer by using tool J 8614-01 to hold the pinion flange using a socket and driver. Discard existing pinion flange, nut, washer, and seal deflector (Figure 2). 6. Remove the pinion flange using tool J 8614-01, J 8614-02 and J 8614-03 (Figure 3) while using a suitable container to catch any fluid that may drain from the rear axle when removing the pinion flange. 7. Inspect the pinion oil seal for any signs of damage or contamination. If either condition exists, replace the pinion oil seal (P/N 26026792). Install or Connect (Figures 1, 2, and 3) 1. Apply a seal lubricant (GM P/N 1052497) to the outside of the pinion flange. 2. Install the pinion flange. Notice: DO NOT ATTEMPT TO HAMMER THE PINION FLANGE ONTO THE REAR AXLE PINION STEM AS IT MAY CAUSE DAMAGE TO THE PINION BEARINGS. 3. Install the washer and flange nut on the pinion stem shaft. Tighten ^ Hold the companion flange with J 8614-01 while tightening the flange nut on the pinion stem. ^ Tighten the pinion nut a little at a time, rotating the pinion occasionally to ensure proper bearing seating. Also, take frequent pinion bearing torque pre-load readings until the original torque value is obtained (Figure 2). Page 1433 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Page 8788 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Interior - Noise From Windshield Pillar Area Windshield: Customer Interest Interior - Noise From Windshield Pillar Area BULLETIN NUMBER: 92-10-130 SECTION: 10 NUMBER: 1 CORPORATE REFERENCE NUMBER: 261610 DATE: September 1992 SUBJECT: NOISE FROM WINDSHIELD PILLAR AREA (DIAGNOSE/INSTALL FELT TAPE) MODELS: 1986-92 S1/T1 UTILITY TRUCKS Some 1986-92 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm mil to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE Prior to installing the felt tape, it should be determined IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in fmnt of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screw drivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. SERVICE PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, see chart. Specifications Idle Speed: Specifications CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Auto D 550 5-40 CL [1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). Page 4794 Brake Master Cylinder: Service and Repair Master Cylinder Removal Master Cylinder CAUTION: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, drip pans and fender covers to prevent brake fluid from contacting these areas. 1. On vehicles with manual brakes, disconnect the master cylinder pushrod from the brake pedal. 2. On all models, disconnect all wire connectors from the master cylinder components. 3. Disconnect the brake lines from the master cylinder. Cover the ends of the lines to prevent dirt from entering system. 4. Remove the master cylinder mounting nuts. 5. Remove the combination valve bracket. 6. Remove the master cylinder. CAUTION: Do not allow brake fluid to fall on the Anti-Lock control module, connectors or wiring. For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Locations Engine Wiring, LH Side Page 6911 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Locations Steering Column Page 7221 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 7518 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 5610 Power Steering Pump: Testing and Inspection Using Power Steering Gauge No. J-5176-D All tests are made with engine idling at normal operating temperature. Check idle speed adjustment and, if necessary, adjust to correct specification. 1. Place a container under steering gear or pump. 2. With engine Off, disconnect pressure hose at steering gear or power steering pump, then install J-5176-D to both hoses using adapter fitting No. J-5176-20 or equivalent. Gauge must be installed between shutoff valve and pump. 3. Open shutoff valve. 4. Remove filler cap from pump reservoir and check fluid level. fill pump reservoir with power steering fluid to full mark on dipstick. Start engine and, momentarily holding steering wheel against stop, check connections for leakage. Do not hold wheel against stop for more than five seconds as pump can be damaged internally. 5. Bleed power steering system. 6. Insert thermometer No. J-5421-02 or equivalent in reservoir filler opening. Move steering wheel from stop to stop several times until thermometer indicates that hydraulic fluid in reservoir has reached a temperature Of 150-170 °F. To prevent flat spotting tires, do not turn steering wheel more than five times without rolling vehicle to change tire to floor contact area. 7. Check pump fluid level. Add fluid if required. 8. When engine is at normal operating temperature, the initial pressure on gauge (valve open) should be within 80-125 psi. If pressure is in excess of 200 psi., check hoses for restrictions and poppet valve for proper assembly. 9. Open and close gauge valve fully three times. Do not leave valve closed for more than five seconds as pump could be damaged internally. 10. Record highest pressures attained each time. a. If pressures recorded are within specifications, and range of readings is within 50 psi., pump is functioning within specification. b. If pressures recorded are constant but more than 100 psi., below minimum specification, replace flow control valve and recheck. If pressures are still low, replace rotating group in pump. c. If pressure recorded are high, but do not repeat within 50 psi., flow control valve is sticking. Remove and clean valve. Remove any burrs using crocus cloth or fine hone. If system contains some dirt, flush system. If it is exceptionally dirty, both pump and gear must be completely disassembled, cleaned, flushed and reassembled before further use. 11. If pump checks within specifications, leave valve open and turn steering wheel to both stops. Record highest pressures and compare with maximum pump pressure recorded. If maximum pressure cannot be reached in either (or one) side of gear, gear is leaking internally and must be disassembled and repaired. 12. Turn engine Off, remove testing gauge, reconnect pressure hose, check fluid level and/or make needed repairs. 13. If problem still exists, steering and from suspension must be thoroughly examined. Page 7418 Symbol Identification Page 3864 Page 963 Compression Check: Testing and Inspection COMPRESSION CHECK - Disconnect the primary terminal from the ignition coil. - Remove all spark plugs. - Block the throttle plate wide open. - Make sure the battery is fully charged. Starting with the compression gauge at zero, crank the engine through four compression strokes (four "puffs"). - Make the compression check at each cylinder and record each reading. - If some cylinders have low compression, inject 15 ml (one table spoon, or 3 squirts from a pump type oil can) of engine oil into the combustion chamber through the spark plug hole. - Minimum compression recorded in any one cylinder should not be less than 70 percent of the highest cylinder, and no cylinder should read less than 690 kPa (100 psi). Normal Compression: Compression builds up quickly and evenly to specified compression on each cylinder. Piston Rings Leaking: Compression low on first stroke, tends to build up on following strokes, but does not reach normal. Improves considerably with addition of oil. Valves Leaking: Low on first stroke. Does not tend to build up on following strokes. Does not improve much with addition of oil. Head Gasket Leakage: If two adjacent cylinder have lower than normal compression, and injecting oil into cylinders does not increase the compression, the cause may be a head gasket leak between the cylinders. Page 2005 Oil Pressure Sender: Locations Engine Sensor Locations. Top Rear Of Engine Applicable to: Except 4.3L/V6-262 HP & 4.3L/V6-262 Turbo Engines Page 6598 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 7191 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 3519 Intake Manifold Tuning Valve: Description and Operation CMFI Air Flow Diagram Intake Manifold Tuning Valve Circuit Page 1168 Important: All of the following parts are NOT NEEDED for a normal retrofit. Follow the bulletin procedures to determine which parts you need! Individual vehicle kits are not necessary, since most of the parts are generic and only a few parts are needed for most vehicles. GEO Parts are listed in "Platform Details." Parts are currently available from GMSPO. D. Warranty Information 1. Vehicle Still Within the Original New Vehicle Limited Warranty Period When GM models for the years listed in the bulletin require repairs to the refrigerant system and the vehicles are still covered under the New Specifications Radiator Cap: Specifications Relief Pressure Relief Pressure Radiator Cap Relief Pressure 15 psi Page 3443 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Page 819 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Page 4646 Removing Dust Boot 6. Carefully pry dust boot out of bore. 7. Using a small piece of wood or plastic, remove piston seal from bore. CAUTION: Do not use a metal tool of any kind to remove seal as it may damage bore. 8. Remove bleeder screw. ASSEMBLY NOTICE: Clean all parts in denatured alcohol or brake parts cleaner before assembly and dry the parts with dry compressed air. 1. Inspect caliper bore for scoring, nicks, corrosion or wear. Replace caliper housing if bore will not clean up with crocus cloth. 2. Lubricate caliper piston bore and new piston seal with clean brake fluid. Position seal in bore groove. Fig. 6 Installing boot to piston 3. Lubricate piston with clean brake fluid and assemble a new boot into the groove in the piston so the fold faces the open end of the piston, Fig. 6. 4. Using care not to unseat the seal, insert piston into bore and force the piston to the bottom of the bore. Page 2133 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Page 5706 5. New cotter pin (68) and bend pin ends against the nut. 6. Grease fittings and lubricate the ball joint until grease appears at the seal. 7. Caliper. 8. Wheel and tire assembly and lower the vehicle. 9. Check the front end alignment. Description and Operation Driver Information Center (DIC): Description and Operation DIGITAL I/P The Digital Electronic Instrument Panel contains vacuum fluorescent displays for the Speedometer, Fuel Gage, Oil Pressure Gage, Temperature Gage and Voltmeter. The Turn Lamps, Safety Belt Lamp, SERVICE ENGINE SOON Lamp, BRAKE Lamp, Headlamp High Beam Indicator and SHIFT Lamp (manual transmission) use standard bulbs and operate the same as the Base and Gage Clusters. Battery voltage to the Cluster is supplied by the ORN (40) wire. This circuit voltage is used for the memory to maintain the total and trip mileages for the odometers. Ignition voltage to the Cluster is supplied by the PNK/WHT (39) wire. This circuit supplies voltage to the vacuum fluorescent displays and the BRAKE and SERVICE ENGINE SOON indicators and the Voltmeter. The other circuits to the Cluster provide the various signals necessary to operate the displays and indicators. When the Ignition Switch is turned to RUN, all of the segments of the vacuum fluorescent displays are displayed for about two seconds. The displays then indicate current levels. The vacuum fluorescent displays can be switched between English and Metric by the E/M switch. When the E/M switch is open, the displays are in English. When the E/M switch is closed, the displays are in Metric. CLUSTER DIMMING When the Ignition Switch is in RUN, the displays are at full brightness. When the Light Switch is in PARK or HEAD, the Cluster senses that the lights are on through the BRN (9) wire. This allows the display brightness to be controlled by the Panel and Interior Lamp Switch through the GRA (9) wire. SPEEDOMETER/ODOMETER/TRIP ODOMETER These displays receive a signal from the Vehicle Speed Sensor Buffer (DRAC) through the LT BLU/BLK (824) wire. The Vehicle Speed Sensor Buffer (DRAC) converts the speed signal from the Vehicle Speed Sensor to 4000 pulses per mile. A different Vehicle Speed Sensor Buffer (DRAC) is used for each axle ratio to convert the signal. The Speedometer indicates vehicle speed in miles per hour or kilometers per hour depending on the E/M Switch position. Speeds below 1.4 mph may be displayed as "0." The odometer/trip odometer display is mounted on a separate board attached to the main display board. The odometer displays the total vehicle mileage up to 999,999 miles in the English mode. If the mileage exceeds this, the display flashes ERROR. In Metric mode, the display will flash ERROR when it exceeds 999,999 kilometers. The English display will show the normal display. The display can be switched from total odometer to trip odometer by pushing the trip switch. When the TRIP Switch is open, the total mileage is displayed. When the TRIP Switch is closed, the trip mileage is displayed. The Trip Odometer can be reset to 0 by pushing the RESET Switch. The display must be in the TRIP mode to be reset. The accumulated mileage of the two displays is gored in a nonvolatile memory chip to prevent losing this data if the battery or cluster is disconnected. If the Cluster is replaced, the Odometer Display can be transferred to the new cluster. FUEL GAGE DISPLAY The Fuel Gage Display shows the fuel level in the tank. This signal is supplied to the Cluster through the PNK (3O) wire. With low fuel level in the tank, the sender resistance is low. With high fuel level in the tank, the sender resistance is high. If the fuel level in the fuel tank drops below approximately 11 liters (3 gallons) in a 75-liter (20-gallon) tank, a box around the Fuel Gage ISO Symbol flashes to indicate low fuel level. OIL PRESSURE GAGE DISPLAY The Oil Pressure Gage Display shows the engine operating oil pressure. This signal is supplied to the Cluster through the TAN (31) wire. With low oil pressure, the sender resistance is low. With high oil pressure, the sender resistance is high. If engine oil pressure drops below 69 kPa (10 psi), a box around the Oil Pressure Gage ISO Symbol flashes to indicate low oil pressure. COOLANT TEMPERATURE GAGE DISPLAY The Coolant Temperature Gage Display shows the engine coolant temperature. This signal is sent to the cluster through the DK GRN (35) wire. With Page 6901 Figure 7 Figure 8 Figure 9 Figure 10 Page 6296 Control Assembly Replacement Page 1308 Fuse Block Details Page 4867 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Tires - Slipping on Rim Wheels: All Technical Service Bulletins Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. PROM - Powertrain Control Module Reprogramming PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Powertrain Control Module Reprogramming File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-04-053 Date: November, 1999 INFORMATION Subject: Powertrain Control Module (PCM) Reprogramming (Do Not Reprogram Using the Same Download Files as Those Already Present in The Control Module) Models: 1990-2000 Passenger Cars and Trucks with Reprogrammable PCM It is strongly recommended to NOT reinstall the same software and/or calibration download file(s) into the powertrain control module as those that are already present in the PCM. There is no technical reason that the download files inside the PCM would ever become corrupted after the control module had previously been successfully programmed. A P0601 (Control Module Read Only Memory) Diagnostic Trouble Code would set in memory and the MIL would be illuminated if the controller memory became corrupted. The Techline Information System 2000 (TIS 2000) PC, combined with vehicle information gained through the Tech 2, can determine when an attempt to reprogram a PCM using the same download files (as those already in the control module) is being requested. If this is attempted, the TIS 2000 PC currently displays the following message: Notice: THE CALIBRATION SELECTED IS THE CURRENT CALIBRATION IN THE CONTROL MODULE. PROGRAMMING WITH THE SAME DOWNLOAD FILES IS NOT AN EFFECTIVE REPAIR. SELECT ( YES ) TO CONTINUE PROGRAMMING THE CONTROL MODULE,OR ( NO ) TO CANCEL. Effective in the first quarter of 2000, the TIS 2000 PC will indicate: Important: THE CALIBRATION SELECTED IS ALREADY THE CURRENT CALIBRATION IN THE CONTROL MODULE. REPROGRAMMING WITH THE SAME DOWNLOAD FILE IS NOT ALLOWED. Certain learned values, such as: (but not limited to) ^ fuel trim (previously known as block learn memory), ^ IAC learned position in various park/neutral and air conditioning on/off combinations, ^ certain OBDII diagnostic thresholds, ^ automatic transmission shift adapts will revert back to their unlearned starting point values after a reprogramming event occurs. It is feasible that the engine or transmission might temporarily operate differently after a reprogramming event, until these values are re-learned. Relearning occurs while operating the vehicle through normal driving routines. If the same download files are simply reinstalled, any changes noticed in engine operation will likely disappear in a short amount of time and/or driving distance. Reprogramming the control module with the same download files that already exist in the module will only accomplish a warranty claim for a non-effective repair, and a likely comeback. Page 7427 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7234 Symbol Identification Diagrams Fuel Injector Line: Diagrams Fig. 8 Lower Intake Manifold Tightening Sequence Page 5260 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 4278 7. Rotate cage several revolutions to assure normal bearing contact. 8. Press flange or yoke against forward bearing and install washer and pinion shaft nut. 9. Place pinion and cage assembly over carrier studs, hold flange with suitable tool, and torque pinion shaft nut to 350 ft. lbs. 10. Check pinion bearing preload torque. If rotating torque is not within 5 to 15 pound inches, disassemble, adjust spacer, reassemble, and recheck preload torque. Use thinner spacer to increase or thicker spacer to decrease preload. 11. Hold flange with suitable tool and remove pinion shaft nut and flange. 12. Lubricate pinion shaft oil seal and cover outer edge of seal body with non-hardening sealing compound, then press seal against cover shoulder with suitable tool. 13. Install new gasket and bearing cover. 14. Press flange against forward bearing and install washer and pinion shaft nut, torquing nut to 350 ft. lbs. Page 355 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 4544 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 5037 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 1762 Valve: Specifications Stem To Guide Clearance Stem To Guide Clearance Stem To Guide Clearance Intake Standard 0.0010-0.0027 in Service Limit 0.0037 in Exhaust Standard 0.0010-0.0027 in Service Limit 0.0047 in Page 8579 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Suspension - Shock Absorber/Strut Leakage Information Suspension Strut / Shock Absorber: Technical Service Bulletins Suspension - Shock Absorber/Strut Leakage Information INFORMATION Bulletin No.: 05-03-08-002C Date: October 16, 2009 Subject: Information on Replacement of Shock Absorbers and Struts Due to Fluid Leaks Models: 2010 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2010 model year and Inspection Procedures. Please discard Corporate Bulletin Number 05-03-08-002B (Section 03 - Suspension). This bulletin is intended to help identify the severity of shock absorber and strut fluid seepage. Improper diagnosis may lead to components being replaced that are within the manufacturer's specification. Shock absorbers and strut assemblies are fluid-filled components and will normally exhibit some seepage. Seepage is defined as oil film or dust accumulation on the exterior of the shock housing. Shock absorbers and struts are not to be replaced under warranty for seepage. Use the following information to determine if the condition is normal acceptable seepage or a defective component. Important Electronically controlled shock absorbers (MR) may have a tendency to attract dust to this oil film. Often this film and dust can be wiped off and will not return until similar mileage is accumulated again. Inspection Procedure Note The shock absorber or strut assembly DOES NOT have to be removed from the vehicle to perform the following inspection procedure. Use the following descriptions and graphics to determine the serviceability of the component. Shock Absorbers Do Not Replace shock absorbers displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom or top of the shock absorber and not originating from the shaft seal (the upper part of the lower shock tube). 2. Light film/residue on approximately 1/3 (a) or less of the lower shock tube (A) and originating from the shaft seal. Replace shock absorbers displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the lower shock tube and originating from the shaft seal. 4. An extreme wet film of oil covering more than 1/3 (b) of the lower shock tube and originating from the shaft seal. Coil-over Shock Absorber Adjustments Idle Speed Control Motor: Adjustments Base Idle Speed is not adjustable on this engine and is controlled by the control module. Refer to FUEL SUPPLY AND AIR INDUCTION/ADJUSTMENT PROCEDURES for adjusting Controlled Idle Speed. Page 866 Alignment: Service and Repair Front Toe Adjustment Fig. 2 Tie Rod & Clamp Sleeve Positioning - To adjust, loosen clamp bolts at each end of steering tie rod adjustable sleeves. - With steering wheel in straight ahead position, turn tie rod adjusting sleeves to obtain proper adjustment. - After adjusting, check that number of threads showing on each end of sleeve are equal and that the tie rod end housings are at the right angles to steering arm. - Position tie rod clamps and sleeves, Fig. 2, and torque nuts to specification. Page 8495 Rear Lamps Harness Page 8123 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Paint - Identification/Repair of Colorcoat Delamination Paint: Customer Interest Paint - Identification/Repair of Colorcoat Delamination BULLETIN NUMBER: 92-1O-134A SECTION: 10 Body NUMBER: 4 CORPORATE REFERENCE NUMBER: 231054R DATE: July 1993 SUBJECT: SERVICE PROCEDURES FOR IDENTIFICATION AND REPAIR OF PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER MODELS: 1988-92 TRUCKS THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 92-10-134 (CORP # 231054R), DATED OCTOBER 1992. IT IS BEING REVISED TO REMOVE THE COVER LETTER PORTION AND SUBJECT STATEMENT NOW INCLUDES NOTE FOR TRUCKS AND REVISES THE MONOCOAT MATERIAL ALLOWANCES ON "G", "S/T" AND SOME "R/V" MODELS. THE ALLOWANCE FOR "ADD FOR TWO-TONE" ON G AND S/T TRUCKS HAS BEEN CHANGED. ALL COPIES OF 92-10-134 SHOULD BE DISCARDED. The revisions are the result of changes to the MONOCOAT (ENAMEL) material allowance charts published in June, 1993. Six (6) of the "G" model revisions use Basecoat/Clearcoat material allowance codes. THESE ARE TO BE USED AS DOLLAR REFERENCES ONLY, AND ARE MARKED WITH A # INDICATOR. Continue to repair these vehicles with monocoat materials. DO NOT repair these vehicles with Basecoat/Clearcoat products. Use the latest (June, 1993) material allowance charts when submitting claims. SUBJECT: Service procedures for the repair of paint colorcoat delamination from elpo primer (repaint entire body above the body side moldings, except trucks as noted). APPLICATION: 1988-1992 LIGHT DUTY TRUCKS (C/K, R/V, S/T, M/L AND G) This bulletin cancels and supersedes service procedures and time allowances on all previous bulletins regarding paint DELAMINATION. Due to the use of new procedures, add times for optional equipment, and designating specific hardware items for removal, the published labor times will not be the same as previously published. CONDITION This bulletin is being issued to assure that the correct procedure is followed to repair a condition known as DELAMINATION. Some of the above listed passenger cars, light duty trucks, and vans may have DELAMINATION (peeling) of the paint color-coat from the ELPO primer depending upon variable factors including prolonged exposure to sunlight and humidity. Blues, Grays, Silvers and Black Metallics are the colors that have the highest potential for this condition. On rare occasions, other colors may be involved. Important DELAMINATION is different than other paint conditions and/or damage. A proper problem identification is necessary, and the service procedure that follows is specific to the proper repair of DELAMINATION and must be followed. The information in this bulletin covers Paint DELAMINATION of the colorcoat from the ELPO primer ONLY. It does not address any other paint conditions. Procedures for the repair of other paint conditions (stone chips, scratches, environmental damage, clearcoat peeling, runs, dirt, fading, etc.) will not effectively repair DELAMINATION and customer dissatisfaction will result. CAUSE This condition may occur on vehicles produced in plants where the paint process does not call for application of a primer surfacer. Under certain conditions, ultraviolet light can penetrate the colorcoat, sometimes causing a reaction and separation of portions of the colorcoat from the ELPO (electrocoat) primer. PROBLEM IDENTIFICATION: Page 6716 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 1479 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Testing and Inspection Pick-Up Coil: Testing and Inspection Fig. 4 Pickup coil test connections Note Make sure the ignition switch is "OFF". 1. Remove distributor cap. 2. Disconnect pickup coil connector from IC module. 3. Connect ohmmeter as shown in step 1, and flex pickup coil leads while observing meter. Meter should indicate infinite resistance at all times. If not, pickup coil is defective. 4. Connect ohmmeter as shown in step 2, and flex pickup coil leads while observing meter. Meter reading should remain constant between 500 and 1500 ohms. If not, replace pickup coil. Note To replace the coil, remove the distributor. Page 7577 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 5833 degradation. Important Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Disclaimer Page 7604 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 368 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 5660 Fig. 3 Over-center preload adjustment Prior to adjusting the steering gear, all outside loads must be removed. 1. Disconnect battery ground cable, then raise and support vehicle. 2. Remove pitman arm nut, then mark relationship of pitman arm to pitman shaft to aid during reassembly. 3. Remove pitman arm using a suitable puller. 4. Loosen steering gear adjuster plug lock nut, then back off adjuster plug 1/4 turn, Fig. 2. 5. Remove horn cap or cover to gain access to the steering wheel attaching nut. 6. Turn steering wheel gently in one direction to stop, then turn back 1/2 turn to position steering gear away from ``high point'' load position. Do not turn wheel hard against steering stops with pitman arm disconnected as damage to gear ball guides can result. 7. Position suitable inch pound torque wrench on steering wheel hub nut, Fig. 3, then while rotating steering wheel with inch pound wrench through a 90 ° arc, record and measure ``bearing drag.'' Do not use an inch pound wrench of more than 50 inch pound capacity. 8. Adjust thrust bearing preload as follows: a. Torque adjuster plug, Fig. 2, until proper loading preload is 0 (6.5 inch lbs.). b. Tighten adjuster nut to specifications. c. If gear feels lumpy after adjustment, bearing damage is indicated. Gear should be disassembled and inspected as necessary. Locations Typical Distributor Components Page 1824 The dexos (TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos (TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos (TM)specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 2(TM) engine oil. GM dexos 2(TM) Engine Oil Specification - dexos 2(TM) is approved and recommended by GM for use in Europe starting in model year 2010 vehicles, regardless of where the vehicle was manufactured. - dexos 2(TM) is the recommended service fill oil for European gasoline engines. Important The Duramax(TM) diesel engine is the exception and requires lubricants meeting specification CJ-4. - dexos 2(TM) is the recommended service fill oil for European light-duty diesel engines and replaces GM-LL-B-025 and GM-LL-A-025. - dexos 2(TM) protects diesel engines from harmful soot deposits and is designed with limits on certain chemical components to prolong catalyst life and protect expensive emission reduction systems. It is a robust oil, resisting degradation between oil changes and maintaining optimum performance longer. Disclaimer Page 1334 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 3360 Fuel Filler Hose: Description and Operation Fuel Filler Neck To help prevent refueling with leaded gasoline, the fuel filler neck on a gasoline engine vehicles has a built-in restrictor and deflector. The opening in the restrictor will only admit the smaller unleaded gas nozzle spout, which must be fully inserted to bypass the deflector. Attempted refueling with a leaded gas nozzle, or failure to fully insert the unleaded gas nozzle will result in gasoline splashing back out of the filler neck. Page 2709 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Adjustments Idle Speed Control Motor: Adjustments Base Idle Speed is not adjustable on this engine and is controlled by the control module. Refer to FUEL SUPPLY AND AIR INDUCTION/ADJUSTMENT PROCEDURES for adjusting Controlled Idle Speed. Aluminum Wheels - Cosmetic Damage During Balancing Wheels: All Technical Service Bulletins Aluminum Wheels - Cosmetic Damage During Balancing Number: 93-197-3E Section: 3E Date: MAY 1993 Corporate Bulletin No.: 393502 ASE No.: A4 Subject: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING Model and Year: 1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V 1990-93 LUMINA APV Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Page 7094 (electrocoat) primer. PROBLEM IDENTIFICATION: On a clean surface, at or above room temperature, firmly apply a 2" wide piece of masking tape and pull upward quickly. DO NOT USE duct tape, cloth backed tape or other aggressive tapes. If the colorcoat flakes or peels away from the ELPO (leaving the ELPO intact) the colorcoat is delaminating and the vehicle should be repaired using the "Paint Repair Procedure" contained in this bulletin. This test SHOULD ONLY BE APPLIED TO A VEHICLE SHOWING THE CONDITION, (peeling/delamination) and NOT in areas of stone chipping or other obvious damage. These "other" conditions should be repaired following standard paint repair procedures. CORRECTION Refinish the ENTIRE BODY ABOVE THE BODY SIDE MOLDINGS using the following repair procedure. It is important that ALL surfaces above the body side moldings (including recessed areas around door handles) be refinished, as these surfaces may show the same DELAMINATION (peeling) condition at a later date. Note: Many vehicles have some type of plastic exterior body panels (cowl vent grilles, fascias, front end panels, rear fenders, etc.). These panels are not subject to DELAMINATION and therefore do not require refinishing. If painting of these panels is required for color uniformity, scuff sand and colorcoat only (and clearcoat if basecoat/clearcoat system is used). Note: Two tone lines, feature lines or body side molding treatments near mid-door height are appropriate break lines. If no such convenient break lines are present, the entire panel above the next lower break line must be refinished and the portion of the panel below that break line should be COLORCOATED ONLY (and clearcoated if basecoat/clearcoat system is used) for color uniformity of the repair. Note: Pickup boxes which are covered by caps, bedliners or tonneau covers do not receive direct exposure to sunlight, and normally would not be repaired under this procedure. However, if the inside of the box has been uncovered and experienced DELAMINATION, use the appropriate Labor Operation Number. Note: Certain two tone applications on trucks using the high potential colors (Blues, Grays and Silvers) may require that only portions of the vehicle surface be refinished. Examples would be: Example 1. Blues, Grays and Silvers as "insert colors" on vertical surfaces with other, non-high potential colors above the insert (or break line). Action: Refinish the "insert color" only, between the break line and body side molding (or to the lower feature line on certain vehicles). Example 2. Blues, Grays and Silvers on surfaces above the break line with other, non-high potential colors as "insert colors". Action: Refinish the surfaces above the "insert color" or break line only. Example 3. Blues, Grays and Silvers used as both the primary and "insert colors". Action: Refinish both high potential color surfaces above the body side moldings (or to the lower feature line on certain vehicles). Vehicles should be repaired with the same type materials they were manufactured with; repair basecoat/clearcoat with basecoat/clearcoat materials and monocoat with monocoat. PAINT REPAIR PROCEDURE 1. Some vehicle components will be removed from the vehicle while others will require masking. The list located at the end of this bulletin will establish the removal items. Items not found on the list and non-repair areas are to be masked. 2. Prior to removing the paint finish, clean the area to be refinished with an appropriate wax and grease remover to remove any contaminants. 3. Remove the original finish of paint down to the ELPO primer surface using an orbital D.A. sander, leaving the ELPO surface intact. This can be done in "stages" using 80 grit (or finer) discs to remove the majority of coating, followed with 180 grit (or finer) discs to remove the remainder of material down to the ELPO surface and any chalky residue or degraded ELPO that may remain. Avoid sanding through ELPO to bare metal in order to retain maximum corrosion protection. Tools - Keyless Entry Transmitter Tester Keyless Entry Transmitter: Technical Service Bulletins Tools - Keyless Entry Transmitter Tester File In Section: 9 - Accessories Bulletin No.: 83-90-12 Date: August, 1998 INFORMATION Subject: Essential Tool J 43241 Remote Keyless Entry and Passive Keyless Entry Transmitter Tester Models: 1990-99 Passenger Cars and Trucks with Remote Keyless Entry or Passive Keyless Entry Systems A new essential tool, J 43241 Remote Keyless Entry Transmitter Tester, has been sent to all GM Dealers. This tester can be used on all RKE and PKE systems, on past as well as current models. Locations Switch: Locations Anti-Lock Brake Components. In Front Axle Applicable to: 1992 Blazer & Jimmy Page 4570 Brake Fluid Pump: Electrical Diagrams Antilock Brakes Wiring Circuit Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Page 639 Engine Wiring, LH Side Page 7627 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 3694 SERVICE PARTS INFORMATION WARRANTY INFORMATION Page 3935 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 6210 Compressor Clutch Coil: Service and Repair With HR100T/HR110T Compressor V-Groove Drive - 4 Pole Clutch Remove or Disconnect Perform Steps 1 through 4 of COMPRESSOR CLUTCH ROTOR AND/OR BEARING removal procedure but do not loosen or remove the pulley rim mounting screws until the Clutch Rotor, Coil and Pulley Rim assembly have been removed from the Front Head. Be careful not to drop the Puller Guide J 25031 when removing the assembly. 2. Remove the pulley rim mounting screws and discard. 3. Slide the pulley rim off the Rotor and Hub assembly The Pulley Rim and the Clutch Coil (Fig. 24) are replaceable at this point. Install or Connect 1. Assemble the Clutch Coil, Pulley Rim and the Clutch Rotor and Bearing assembly as shown in Figure 27. Use new screws and apply sealer GM 12345382 (Loctite 242, or equivalent) to screw threads but do not lock the screws in place. 2. Place the assembly on the neck of the Front Head and seat into place using Rotor & Bearing Installer J 26271-A (Fig. 14). Page 6603 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Page 1011 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 2508 Engine Wiring, LH Side Page 6566 low coolant temperature, the sender resistance is high. With high coolant temperature the sender resistance is low. If the coolant temperature exceeds 118°C (245°F), a box around the Coolant Temperature Gage ISO Symbol flashes to indicate an engine overheat condition. VOLTMETER DISPLAY The Voltmeter Display shows the battery voltage. The Voltmeter is connected to the PNK/BLK (39) wire and the BLK (150) wire. If the generator output is high, low or 0 volts, a box around the Voltmeter ISO Symbol flashes to indicate a problem with the charging system. This signal is sent to the cluster through the BRN (25) wire. TACHOMETER DISPLAY The Tachometer Display shows engine revolutions per minute (RPM). The Tachometer is connected to the WHT (121) wire. The Tachometer has a total range of 0-5500 RPM. The YELLOW warning region has a range of 4500-5000 RPM and the RED warning region has a range of 5000-5500 RPM. Page 4422 Fluid - M/T: Fluid Type Specifications Warner T-5 (77MM) 5 Speed Lubricant Type ..................................................................................................................................... .......................................................... Dexron II ATF MUNCIE 5LM60 (HM-290) 4 & 5 Speed Lubricant Type ..................................................................................................................................... ................................ Syncromesh Trans Fluid T2850 Page 4984 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 454 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Page 6173 Installing Clutch Coil Assembly 3. Center the J 8433-1 puller crossbar in the countersunk center hole of the J 33024 clutch coil installer. Install the J 33026-2 through bolts and washers through the crossbar slots and thread them into the holding fixture J 33026 to full fixture thickness. 4. Turn the center forcing screw of the J 8433-1 puller crossbar to force the clutch coil onto the front head. Be sure clutch coil and J 33024 installer stay "in-line" during installation. Staking Clutch Coil To Front Head 5. When coil is fully seated on the front head, use a 1/8" diameter drift punch and stake the front head at three places 120 degrees apart, to ensure clutch coil remains in position. Details Of Stakes In Front Head For Clutch Coil - Stake size should be only one-half the area of the punch tip and be only approximately 0.28-0.35mm (0.010-0.015") deep. 6. Install rotor and bearing assembly and the clutch plate and hub assembly. Page 6612 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 5071 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7187 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Specifications Shift Solenoid: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Page 1298 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 4196 For vehicles repaired under warranty use: Page 2363 Engine Compartment Components Front Of Engine Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 HP Engine STD Engine Page 7978 Oil Pressure Warning Lamp/Indicator: Testing and Inspection On some models, the oil pressure indicator light also serves as the electric choke defect indicator. If Oil or ENG. indicator light does not light, check to ensure electric choke is not disconnected at carburetor. Also check for defect in electric choke heater, blown gauge fuse or defect in lamp or wiring circuit. If indicator light stays on with engine running possible causes are: low oil pressure, switch to indicator light open circuit, disconnected oil pressure switch connector or oil pressure gauge or radio fuse has blown. The oil pressure warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on, replace the bulb. If the warning light goes on when the wire is grounded, check the engine unit for a poor ground, or improper installation. (The presence of sealing compound on the threads of the engine unit will cause a poor ground.) If the unit is found to be properly grounded and installed, replace the unit. If the warning light remains lit when it normally should be out, replace the engine unit before proceeding to determine the cause for low pressure indication. The warning light will sometimes light or flicker when the engine is idling, even if oil pressure is adequate. However, the light should go out when the engine speed is increased. Driveline - Launch Shudder Pinion Flange: All Technical Service Bulletins Driveline - Launch Shudder FILE IN SECTION: 4 - Drive Axle BULLETIN NO.: 56-41-02 DATE: July, 1995 SUBJECT: Driveline Launch Shudder (Install Newly Designed Propeller Shaft) MODELS: 1992-93 Chevrolet and GMC Truck S10803 Models (Pick-up, Regular Cab, and Long Bed) 1992-94 Chevrolet and GMC Truck S10653 Models (Pick-up, Extended cab, and Short bed) 1992-94 Chevrolet and GMC Truck T10653 Models (Pick-up, Extended cab, and Short bed) with 4.3L V-6 Engines (VINs W, Z - RPOs L35, LB4) and Automatic Transmission CONDITION Some owners of pick ups with 4.3L V-6 engines (RPOs L35, LB4), equipped with a two-piece rear propeller shaft and an automatic transmission, may experience a launch shudder condition. This condition may occur from 0-25 mph (0-40 kph) and is more noticeable during hard acceleration when the vehicle is heavily loaded, or when used as a tow vehicle. CAUSE This condition is caused by the driveline angle changes occurring during engine torque and vehicle payload. CORRECTION To repair this condition a newly designed rear propeller shaft and pinion flange is released for service to reduce driveline launch shudder during 0-25 mph (0-40 kph). SERVICE PROCEDURE Remove or Disconnect (Figures 1, 2, and 3) Tool Required: J 8614-01 Companion Flange Holder 1. Place the vehicle on a hoist that will allow free rotation of the rear wheels. 2. Remove both rear tire wheel and drum assemblies. 3. Remove and discard existing two piece rear propeller shaft assembly, retaining the straps and fasteners. 4. Measure the pre-load on the rear axle pinion flange using an inch pound torque wrench, the amount of torque required to turn the pinion (Figure Specifications Bell Housing: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Bellhousing To Case ........................................................................................................................... ............................................................................... 55 Page 44 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 3433 idle air flow (IAC/passage + PCV + throttle valve + vacuum leaks). - Controlled idle speed is always specified for normal operating conditions. Normal operating condition is engine coolant temperature in operating range, the A/C is "OFF," manual transmission is in neutral or automatic transmission in drive with proper Park/Neutral Position (PNP) switch adjustment. A high or low engine coolant temperature, or A/C clutch engagement may signal the control module to change the IAC counts. - The minimum idle speed is set at the factory with a stop screw. This setting allows enough air flow by the throttle valves to cause the IAC valve pintle to be positioned a calibrated number of steps (counts) from the seat during normal controlled idle operation. The IAC counts will be higher than normal on an engine with less than 500 miles, or an engine operating at high altitude or an engine with an accessory load such as the alternator, A/C, power steering or hydra-boost brakes activated. Results of Incorrect Operation If the pintle is stuck open, the idle speed will remain high. If the pintle is stuck closed, the idle speed will be too low, and stalling may occur. If the pintle is stuck partially open, the idle speed will be higher than normal, and there will be no response to changes in engine load such as A/C ("ON") or transmission in ("Drive"). Page 2164 Contamination Mixing conventional green coolant with DEX-COOL(R) will degrade the service interval from 5 yrs./150,000 miles (240,000 km) to 2 yrs./30,000 miles (50,000 km) if left in the contaminated condition. If contamination occurs, the cooling system must be flushed twice immediately and re-filled with a 50/50 mixture of DEX-COOL(R) and clean water in order to preserve the enhanced properties and extended service interval of DEX-COOL(R). After 5 years/150,000 miles (240,000 km) After 5 yrs/150,000 miles (240,000 km), the coolant should be changed, preferably using a coolant exchanger. If the vehicle was originally equipped with DEX-COOL(R) and has not had problems with contamination from non-DEX-COOL(R) coolants, then the service interval remains the same, and the coolant does not need to be changed for another 5 yrs/150,000 miles (240,000 km) Equipment (Coolant Exchangers) The preferred method of performing coolant replacement is to use a coolant exchanger. A coolant exchanger can replace virtually all of the old coolant with new coolant. Coolant exchangers can be used to perform coolant replacement without spillage, and facilitate easy waste collection. They can also be used to lower the coolant level in a vehicle to allow for less messy servicing of cooling system components. It is recommended that you use a coolant exchanger with a vacuum feature facilitates removing trapped air from the cooling system. This is a substantial time savings over repeatedly thermo cycling the vehicle and topping-off the radiator. The vacuum feature also allows venting of a hot system to relieve system pressure. Approved coolant exchangers are available through the GMDE (General Motors Dealer Equipment) program. For refilling a cooling system that has been partially or fully drained for repairs other than coolant replacement, the Vac-N-Fill Coolant Refill Tool (GE-47716) is recommended to facilitate removal of trapped air from the cooling system during refill. Disclaimer Page 4299 1). Record this measurement for reassemble purposes. This measurement will give the combined pinion bearing and seal pre-load. Also record the number of exposed threads beyond the flange nut on the pinion flange nut. 5. Remove the pinion flange nut and washer by using tool J 8614-01 to hold the pinion flange using a socket and driver. Discard existing pinion flange, nut, washer, and seal deflector (Figure 2). 6. Remove the pinion flange using tool J 8614-01, J 8614-02 and J 8614-03 (Figure 3) while using a suitable container to catch any fluid that may drain from the rear axle when removing the pinion flange. 7. Inspect the pinion oil seal for any signs of damage or contamination. If either condition exists, replace the pinion oil seal (P/N 26026792). Install or Connect (Figures 1, 2, and 3) 1. Apply a seal lubricant (GM P/N 1052497) to the outside of the pinion flange. 2. Install the pinion flange. Notice: DO NOT ATTEMPT TO HAMMER THE PINION FLANGE ONTO THE REAR AXLE PINION STEM AS IT MAY CAUSE DAMAGE TO THE PINION BEARINGS. 3. Install the washer and flange nut on the pinion stem shaft. Tighten ^ Hold the companion flange with J 8614-01 while tightening the flange nut on the pinion stem. ^ Tighten the pinion nut a little at a time, rotating the pinion occasionally to ensure proper bearing seating. Also, take frequent pinion bearing torque pre-load readings until the original torque value is obtained (Figure 2). Page 6095 Wiring Harness Installation Blower Motor Case Assembly REMOVE OR DISCONNECT 1. Electrical connector (77) from blower motor (53). 2. Blower motor flange screws (87). 3. Cooling tube. 4. Blower motor (53). 5. Blower motor fan. Inspect - Blower motor terminals for corrosion. Clean corrosion from the terminals or replace the blower motor (53) as necessary. - Flange of the blower motor (53) for damage or distortion that could cause an air leak. Repair as necessary. - Blower fan for damage and distortion. Repair or replace as necessary. INSTALL OR CONNECT Page 5045 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 8612 ^ Raise the window to the full up position secure the glass to the door frame using cloth backed tape. 1. Door trim panel. 2. Armrest bracket. 3. Water deflector. 4. Battery ground cable. 5. Wire harness from motor. 6. Regulator lift arm roller from the window mount sash. CAUTION: Sector gear must be locked into position. Regulator lift arm is under tension from the counterbalance spring and could cause personal injury if the sector gear is not locked in position. Drilling Hole In Window Regulator. (97 Shown, This Model Similar) Using A Bolt And Nut To Lock Window Regulator. (97 Shown, This Model Similar NOTE: The Manufacturer did not provide a specific image for this year. The two images above are from a 1997 model but are typical. 7. Motor from window regulator. ^ Drill hole through the regulator sector gear and backplate install bolt and nut to lock sector gear in position. ^ Drill Out the motor mounting rivets. INSTALL OR CONNECT TOOL REQUIRED: ^ J-9022-A, Rivet Installer 1. Motor to the regulator. 2. Rivets to the motor and regulator. ^ Use tool J-9022-A. ^ Install 4.8 mm (3/16-inch) rivets. ^ Remove nut and bolt used to lock the sector gear in position. Tires - Correct Inflation Pressure Information Tires: All Technical Service Bulletins Tires - Correct Inflation Pressure Information INFORMATION Bulletin No.: 00-00-90-002J Date: January 28, 2009 Subject: Information on Proper Tire Pressure Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2009 and Prior HUMMER H2, H3, H3T 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years and clarify additional information. Please discard Corporate Bulletin Number 00-00-90-002I (Section 00 - General Information). Important: ^ Adjustment of tire pressure for a customer with a Low Tire Pressure Monitor (TPM) light on and no codes in the TPM system is NOT a warrantable repair. Claims to simply adjust the tire pressure will be rejected. ^ ALL tires (including the spare tire) MUST be set to the recommended inflation pressure stated on the vehicle's tire placard (on driver's door) during the PRE-DELIVERY INSPECTION (PDI). Recommended inflation pressure is not the pressure printed on tire sidewall. ^ Tires may be over-inflated from the assembly plant due to the mounting process. ^ Generally a 5.6°C (10°F) temperature change will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure change. ^ 2008-2009 HUMMER H2 Only - The H2 comes standard with Light Truck "D" Load Range tires with a recommended cold inflation pressure of 289 kPa (42 psi). These tires will alert the driver to a low pressure situation at roughly 262 kPa (38 psi) due to a requirement in FMVSS 138 which specifies a Minimum Activation Pressure for each tire type. This creates a relatively narrow window of "usable" pressure values and the warning will be more sensitive to outside temperature changes during the colder months. As with other cold temperature/tire pressure issues, there is nothing wrong with the system itself. If a vehicle is brought in with this concern, check for tire damage and set all tires to the Recommended Cold Inflation Pressure shown on the vehicle placard. Accurate tire pressures ensure the safe handling and appropriate ride characteristics of GM cars and trucks. It is critical that the tire pressure be adjusted to the specifications on the vehicle¡C■s tire placard during PDI. Ride, handling and road noise concerns may be caused by improperly adjusted tire pressure. The first step in the diagnosis of these concerns is to verify that the tires are inflated to the correct pressures. The recommended tire inflation pressure is listed on the vehicle¡C■s tire placard. The tire placard is located on the driver¡C■s side front or rear door edge, center pillar, or the rear compartment lid. Tip ^ Generally a 5.6°C (10°F) temperature increase will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure increase. ^ The definition of a "cold" tire is one that has been sitting for at least 3 hours, or driven no more than 1.6 km (1 mi). ^ On extremely cold days, if the vehicle has been indoors, it may be necessary to compensate for the low external temperature by adding additional air to the tire during PDI. ^ During cold weather, the Tire Pressure Monitor (TPM) indicator light (a yellow horseshoe with an exclamation point) may illuminate. If this indicator turns off after the tires warm up (reach operating temperature), the tire pressure should be reset to placard pressure at the cold temperature. ^ The TPM system will work correctly with nitrogen in tires. ^ The TPM system is compatible with the GM Vehicle Care Tire Sealant but may not be with other commercially available sealants. Important: ^ Do not use the tire pressure indicated on the tire itself as a guide. Page 7641 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Testing and Inspection Tachometer Is Inoperative Headlight Dimmer Switch Steering Column Page 5099 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 3752 Running change. 4811 4809 BALL 16174808 Running change. 6521 6600 BAWP 16176599 6531 6604 BAWR 16176603 7281 7343 BAZC 16177342 7291 7347 BAZD 16177346 7301 7351 BAZF 16177350 7311 7355 BAZH 16177354 8631 8592 AYZX 16168590 4761 16174786 8641 8597 AYZY 16168596 4781 16174795 8651 8602 AYZZ 16168600 4771 16174790 8661 8606 AZAA 16168605 4791 16174799 8671 8612 AZAB 16168610 4801 16174804 8681 8616 AZAC 16168615 4811 16174808 Page 6209 Details Of Stakes In Front Head For Clutch Coil - Stake size should be only one half the area of the punch tip and only approximately 0.28-0.35mm (0.10-0.015") deep. 6. Install rotor and bearing assembly and the clutch plate and hub assembly according as described previously. Page 7313 Cruise Control Switch: Locations Cruise Control Components, Near Steering Column. Part Of Multi-Function Lever Page 3717 PROM - Programmable Read Only Memory: Service Precautions A PROM is a sensitive electronic part and must be handled with care. If the connector terminals (pins) on the bottom of the PROM are exposed, avoid touching them. Pins can be broken easily, and the PROM can be damaged by static electric discharge. Follow these guidelines when replacing a PROM: ^ Disconnect the battery ground cable before removing a PROM. Reconnect the cable after the new PROM is installed. ^ DO NOT try to remove a PROM from its plastic PROM carrier. ^ Note the direction in which the original PROM and its carrier were installed in the ECM, and install the replacement PROM in the same direction. Most PROM's are marked with a notch at one end for orientation. Many PROM's can be installed in a reversed direction, which will destroy the PROM when power is applied. CAUTION: A PROM can be damaged by static electric discharge. Avoid damage as follows: ^ DO NOT remove a PROM from its packing material until you are ready to install it. DO NOT hold a PROM by its pins. ^ Before entering a vehicle to remove or replace a PROM, touch an exposed metal part of the vehicle to discharge any static charge from your body or use anti-static wrist straps. ^ Avoid sliding across upholstery or carpeting when removing or installing a PROM. If this is not possible, touch an exposed metal part of the vehicle with your free hand before removing a PROM or installing a new one in its socket in the ECM. ^ When available, use an antistatic grounding strap attached to your wrist and clipped to a metal part of the vehicle body to prevent static charges from accumulating. Antistatic, conductive floormats are also available. ^ For some vehicles, it may be desirable to remove the ECM when replacing the PROM. ^ NOTE: See POWERTRAIN MANAGEMENT / SERVICE PRECAUTIONS / VEHICLE DAMAGE WARNINGS / ELECTRICAL PRECAUTIONS Page 6214 Installing Clutch Coil Assembly 3. Center the J 8433-1 puller crossbar in the countersunk center hole of the J 33024 clutch coil installer. Install the J 33026-2 through bolts and washers through the crossbar slots and thread them into the holding fixture J 33026 to full fixture thickness. 4. Turn the center forcing screw of the J 8433-1 puller crossbar to force the clutch coil onto the front head. Be sure clutch coil and J 33024 installer stay "in-line" during installation. Staking Clutch Coil To Front Head 5. When coil is fully seated on the front head, use a 1/8" diameter drift punch and stake the front head at three places 120 degrees apart, to ensure clutch coil remains in position. A/C Recirculation Door - Water Leak Hood Hinge: All Technical Service Bulletins A/C Recirculation Door - Water Leak File In Section: 1 - HVAC Bulletin No.: 56-12-04 Date: April, 1995 Subject: Water Leak at the A/C Recirculation Door (Install New Hood Hinge Seal) Models: 1983-93 Chevrolet and GMC Truck S/T Pickups 1983-94 Chevrolet and GMC Truck S/T Utilities 1991-94 Oldsmobile Bravada Built Prior to the Following VIN Breakpoints: Assembly Plant Division (Plant Code) VIN Breakpoint GMC Truck Pontiac West (0) R0525661 Chevrolet Pontiac West (0) R0168567 Oldsmobile Pontiac West (0) R0704953 GMC Truck Moraine (2) All Chevrolet Moraine (2) All Oldsmobile Moraine (2) All CONDITION Some owners may comment that they have a water leak at the kick panel vent when their A/C controls are in the MAX position and it is raining. CAUSE Water is entering the plenum and cowl area by way of the hood hinge. CORRECTION To correct this condition, remove the current hood hinge seal and replace with a redesigned hood hinge seal. The redesigned seal has foam flaps which restrict water entry. Service Procedure 1. Raise and support the hood. 2. Remove the cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. 3. Remove hood hinge bolts from hood (both sides). 4. Remove hood from vehicle. 5. Remove fender nut and bolt from hinge (both sides). 6. Remove hood hinge from vehicle (both sides). 7. Remove hood hinge seals and replace with redesigned hood hinge seals P/N's 15995797 (LH) and 15995798 (RH). Important: Be sure that hood hinge seals are properly seated and sealed or water leakage could recur. 8. Install hood hinges to vehicle. Important: Apply lubricant to the hood hinges around the hinge to fender bolts. 9. Install fender nuts and bolts to hood hinges. 10. Install hood hinges to hood bolts. Tighten the hinge to hood bolts to 25 Nm (18 lb.ft.). Page 5529 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 8716 Disclaimer Page 1294 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 6149 Bearing Staked In Place The stake metal should not contact the outer face of the bearing to prevent the possibility of distorting the outer race. Stake three (3) places 120° apart as shown in the illustration. Installing Pulley Rotor And Bearing Assembly 5. With the compressor mounted to the J 34992 holding fixture, position the rotor and bearing assembly on the front head. 6. Position the J 33017 pulley rotor and bearing installer and J 33023-A puller pilot directly over the inner race of the bearing. 7. Position puller crossbar J 8433-1 on the puller pilot J 33023-A and assemble the two J 34992-2 through bolts and washers through the puller bar slots and thread them into the J 34992 holding fixture. The thread of the through bolts should engage the full thickness of the holding fixture. 8. Tighten the center screw in the J 8433-1 puller crossbar to force the pulley rotor and bearing assembly onto the compressor front head. Should the J 33017 pulley rotor and bearing installer slip off direct in-line contact with the inner face of the bearing, loosen the J 8433-3 center forcing screw and realign the installer and pilot so that the J 33017 installer will properly clear the front head. 9. Install rotor and bearing assembly retainer ring, using snap ring pliers J 6083. 10. Reinstall clutch plate and hub assembly as described previously. Clutch Coil Remove or Disconnect 1. Perform Steps 1 through 4 of "Clutch Rotor and/or Bearings" removal procedure. Mark clutch coil terminal location on compressor front head. Page 5384 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 5439 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 2587 Speed Sensor And Backup Lamp Switch Wiring - Two-Wheel Drive Models Intake Air Temperature (IAT) Sensor Intake Air Temperature (IAT) Sensor 4.3W Page 3679 SERVICE PARTS INFORMATION WARRANTY INFORMATION Locations EGR Valve Position Sensor: Locations Engine Wiring, LH Side Page 6075 Air Duct: Description and Operation DUCT AND OUTLETS Control of air through the system is regulated by vacuum. At various positions of the levers on the control head, mode doors mix and direct cooled, heated, and outside air through the air ducts. A system of ducts and outlets directs air to the passenger compartment. In cases of poor air output, defroster, heater, AC, and vent ducts should be checked for obstructions such as leaves, dirt, or objects which may have fallen into the ducts from the passenger compartment. Page 5264 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 2618 Knock Sensor: Testing and Inspection Electronic Spark Control (ESC) Circuit Check Page 2544 The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/OXYGEN SENSOR TESTING. Front Wheel Speed Sensor Wheel Speed Sensor: Service and Repair Front Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Disconnect brake caliper assembly and position aside. 3. On two wheel drive models, remove hub and rotor assembly. 4. On four wheel drive models, remove rotor, then hub and bearing assembly. 5. On all models, disconnect wheel sensor electrical connector. 5. Remove sensor wire form upper control arm clip. 6. Remove sensor and splash shield assembly attaching bolts, then remove sensor. 7. Reverse procedure to install. On two wheel drive models, torque sensor and splash shield assembly to steering knuckle attaching bolts to 11 ft. lbs. Page 7415 Rear Of Instrument Cluster. On Brake Pedal Support Page 4980 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 2831 Knock Sensor: Testing and Inspection Electronic Spark Control (ESC) Circuit Check Page 7478 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 3862 Page 6229 Compressor Clutch Hub: Service and Repair With V5 Compressor Remove or Disconnect Removing Shaft Nut 1. Clamp the holding mixture J 34992 a vise and attach compressor to holding fixture with thumb screws J 34992-1. 2. Keep the clutch hub and drive plate assembly from turning by using the clutch hub holding tool J 33027-A. Remove the shaft nut using shaft nut socket J 33022. Clutch Plate And Hub Assembly Removal 3. Thread the Clutch Plate and Hub Assembly Remover J 33013-B into the hub. Hold the body of the remover with a wrench and turn the center Borg Warner - 2 Pinion Pinion Gear: Service and Repair Borg Warner - 2 Pinion 1. Scribe reference mark between drive pinion and driveshaft yoke, then hold yoke with suitable tool and remove pinion nut and yoke. If yoke shows wear in the seal-to-flange contacting surface, the yoke should be replaced. 2. Install original pinion nut a few turns on pinion shaft, then using hammer and drift, tap pinion shaft out of pinion housing. Hold gear end of pinion shaft when removing to prevent it from falling from axle housing. On Corvette models, the pinion preload shims may stick to the pinion housing or the rear bearing during removal. These shims must be collected and kept together for use during reassembly. 3. Remove and discard pinion nut and collapsible spacer. 4. If being replaced, remove front and rear bearing races from pinion housing using drift positioned in race slots and hammer. 5. If rear pinion bearing is being replaced, remove using arbor press and adapters. Measure and record thickness of shim which is found under rear bearing. Page 5081 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 6758 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Locations Backup Lamp Switch: Locations Rear Engine Components. LH Side Of Transmission Applicable to: 1991-92 4.3L/V6-262 Engine, Except Bravada & Automatic Transmission Page 8525 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 1561 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Description and Operation Fuel Economy Warning System: Description and Operation This system actually monitors the engine vacuum just like the vacuum gauge, but registers only low vacuum readings. The light on the instrument panel warns the vehicle operator when engine manifold vacuum drops below the economical limit. Switch operation is similar to that of the oil pressure indicating light, except that the switch opens when vacuum pressure, rather than oil pressure, is applied. Fuel System - 'TOP TIER' Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel System - 'TOP TIER' Detergent Gasoline Information INFORMATION Bulletin No.: 04-06-04-047I Date: August 17, 2009 Subject: TOP TIER Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - U.S. Only Models: 2010 and Prior GM Passenger Cars and Trucks (including Saturn) (U.S. Only) 2003-2010 HUMMER H2 (U.S. Only) 2006-2010 HUMMER H3 (U.S. Only) 2005-2009 Saab 9-7X (U.S. Only) Supercede: This bulletin is being revised to add model years and additional sources to the Top Tier Fuel Retailers list. Please discard Corporate Bulletin Number 04-06-04-047H (Section 06 Engine/Propulsion System). In Canada, refer to Corporate Bulletin Number 05-06-04-022F. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from the use of TOP TIER Detergent Gasoline. Intake valve: - 10,000 miles with TOP TIER Detergent Gasoline Intake valve: - 10,000 miles with Legal Minimum additive Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards As of August 1, 2009, all grades of the following gasoline brands meet the TOP TIER Detergent Gasoline Standards: - Chevron - Chevron-Canada - QuikTrip - Conoco Phillips 66 - 76 Body - Polypropylene Energy Absorber Replacement Front Bumper Reinforcement: Technical Service Bulletins Body - Polypropylene Energy Absorber Replacement Bulletin No.: 07-08-63-001 Date: April 17, 2007 INFORMATION Subject: Information on Repair of Polypropylene Energy Absorbers Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to change the repair information. Please discard Corporate Bulletin Number 63-20-02 (Section 8 - Body and Accessories). Because the energy absorbers are relatively low in cost to replace, it is now more cost efficient to replace the energy absorbers whenever they are damaged. Disclaimer Rockwell Full Floating Axle Axle Shaft Assembly: Service and Repair Rockwell Full Floating Axle Axle Assembly ROCKWELL REAR AXLE ASSEMBLY 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Housing ROCKWELL REAR AXLE HOUSING 1. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Axle Shaft ROCKWELL REAR AXLE SHAFT 1. Remove hub cap, then install slide hammer adapter into tapped hole in axle flange. 2. Attach slide hammer onto adapter, then remove axle shaft from housing. 3. Install axle shaft, ensuring flange and hub splines align. 4. Install new gasket, position flange to hub, then install attaching bolts and tighten to specifications. Bearing & Cup ROCKWELL REAR WHEEL BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: Customer Interest Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 96 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Aluminum Wheels - Cosmetic Damage During Balancing Wheels: Customer Interest Aluminum Wheels - Cosmetic Damage During Balancing Number: 93-197-3E Section: 3E Date: MAY 1993 Corporate Bulletin No.: 393502 ASE No.: A4 Subject: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING Model and Year: 1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V 1990-93 LUMINA APV Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Page 6595 Figure 7 Figure 8 Figure 9 Figure 10 Locations Electronic Spark Control (ESC) Module Page 4982 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 6593 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 8347 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 2901 - Negative battery terminal. Page 3491 Throttle Cable/Linkage: Description and Operation The accelerator control system is a control cable type, attached to an accelerator pedal assembly. Page 2871 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION - Connectors and wires - Housing and insulator for cracks/damage - Sensor tip for silicone contamination (white powdery coating) CAUTION Do NOT perform the following test for more than 2 minutes, as this may cause damage to the catalytic converter. PERFORMANCE TEST Checks working range and response (speed). Warm engine - Install DVOM between sensor and ground (2 volt D.C. range) - "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). - Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. - Drive system lean: Create a vacuum leak from a source that is not an control module input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE After each test the O2 sensor should return to normal operating range within two to three seconds. - O2 Sensor should be replaced for failure to pass any of the tests above. NOTE A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. - Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. HEATING ELEMENT (H20S only) - Turn ignition "OFF". Disconnect electrical connector. - Connect test light between harness terminals "A" and "B". - Turn ignition "ON". Test light should be "ON". If test light is "OFF", connect test light to harness terminal "A" to ground. Light should be "ON" ensuring power circuit is operating correctly. - Turn ignition "OFF". - Using an ohmmeter, measure resistance between terminals A and B. Resistance @ Specified Temperature 3.5 ohms @ 20°C (68°F) 14 ohms @ 350°C (662°F) Page 5658 Fig. 14 Stub shaft torque reading 1. Loosen and remove adjuster plug nut, Fig. 12. 2. Turn adjuster plug clockwise using spanner wrench tool J-7624 or equivalent, Fig. 4, until plug and thrust bearing are firmly bottomed in housing. 3. Scribe an index mark on the housing even with a hole on adjuster plug. 4. Measure back 3/16 - 1/4 inch from first index mark and scribe a second index mark. Fig. 13. 5. Rotate adjuster plug counterclockwise until hole is aligned with second index mark. 6. Install adjuster plug nut, tighten to specifications. 7. Using an inch-pound torque wrench and a 12-point deep socket, measure torque required to turn stub shaft. Take reading with handle of torque wrench near vertical position, Fig. 14. Turn stub shaft to right stop, then back 1/4 turn at an even rate. Record torque reading. 8. Torque reading should be 4-10 inch lbs. If not, adjuster plug may not be tightened properly or may have turned during adjuster plug nut installation. Thrust bearings and races may also be damaged. Over Center Preload Fig. 15 Stub shaft alignment 1. Turn pitman shaft adjuster screw counterclockwise until fully extended, then reverse 1/2 turn clockwise. 2. Rotate stub shaft from stop to stop and count number of turns. 3. Starting at either stop, turn stub shaft halfway back. When gear is centered, flat on stub shaft will face upward and be parallel with side cover, Fig. 15. 4. Place torque wrench on stub shaft and rotate 45° each side of center. Record highest drag torque measured on or near center. 5. Adjust over-center drag torque by loosening adjuster screw jam nut and turning pitman shaft adjuster screw clockwise until correct drag torque is obtained. 6. On new steering gears, add 6-10 inch lbs. torque to previously measured worm bearing preload torque. Do not exceed a total steering gear preload of 18 inch lbs. 7. On used steering gears, add 4-5 inch lbs. torque to previously measured worm bearing preload torque. Do not exceed a total steering gear preload of 14 inch lbs. 8. Install and tighten adjuster screw jam nut to specifications. Page 3035 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 4881 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 946 2.8L - Engine Distributor Components DELCO REMY DISTRIBUTORS Distributors with separate coils are used on light duty truck engines. The ignition coil connects to the distributor cap through a high tension wire. The distributor uses an internal magnetic pickup assembly that consists of a permanent magnet, pole piece with internal teeth, and pickup coil. When the rotating teeth of the timer core line up with the teeth of the pole piece, voltage is induced in the pickup coil. This voltage signals the ignition control module to trigger the primary ignition circuit. Current flow in the primary circuit is interrupted and a high voltage of up to 35,000 volts is induced in the ignition coil secondary winding. This high voltage is directed through the secondary ignition circuit to fire the spark plugs. The distributor used on the 2.8L engine uses a capacitor for radio noise suppression that is integral with the terminal block. IDENTIFICATION The part number (seven digits) is located on a label on the distributor cap. IGNITION CONTROL MODULE The ignition control module is a solid state unit containing many complete circuits. The circuits control spark triggering, switching, current limiting, dwell control, and distributor pickup. The vehicle's computer sends signals to the module to control dwell and spark timing. The module may have seven or eight terminals, depending on the ignition system. POLE PIECE AND COIL ASSEMBLY The pole piece and plate assembly (often referred to as the pickup coil assembly) located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. CAPACITOR The capacitor in the distributor is for radio noise suppression. Page 7573 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 4362 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove brake drum. 4. Remove carrier cover and drain fluid from axle. Remove gasket. 5. Remove locking screw. 6. Remove pinion shaft as follows: a. On models less locking differential, remove pinion shaft from case. b. On models with locking differential, remove pinion shaft partially and rotate case until pinion shaft touches the housing, Fig. 1. c. Using a screwdriver, rotate lock until it aligns with thrust block. 7. Push axle shaft flange toward differential. Do not hammer the shaft to move. 8. Remove lock (13), Fig. 2, from button end of axle shaft. 9. Slide axle shaft out from housing. Do not damage seal. 10. Using axle shaft bearing remover tool No. J-23689 or equivalent, remove oil seal. 11. Remove bearing as follows: a. Using axle shaft bearing remover tool No. J-23689 or equivalent, (for 8 1/2 ring gear), or axle shaft bearing remover tool No. J-29712 or equivalent (for 9 1/2 ring gear), carefully pull bearing from axle. b. Insert appropriate tool into axle bore so it grasps behind the bearing. Tighten nut and washer against bearing face, then pull bearing out using slide hammer with adapter tool No. J-2619-01 or equivalent. 12. Reverse procedure to install. Wheel Bearing/Oil Seal REAR WHEEL BEARING AND OIL SEAL 1. Remove axle shaft as previously described. 2. Use a suitable puller to remove bearing and oil seal. 3. Lubricate wheel bearing and cavity between seal lips with wheel bearing lubricant before installation. 4. Reverse procedure to install. Axle Housing REAR AXLE HOUSING 1. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Axle Shaft REAR AXLE SHAFT 1. Remove bolts that attach axle shaft flange to wheel hub. 2. Tap on flange with a rawhide mallet to loosen axle shaft, then remove axle shaft by twisting shaft with locking pliers. 3. Thoroughly clean both axle shaft flange and end of wheel hub. Any lubricant on these surfaces tends to loosen axle shaft flange bolts. 4. Place a new gasket over axle shaft and position axle shaft in housing so that shaft splines enter differential side gear. Position gasket so that holes are in alignment and install flange-to-hub attaching bolts. Bearing & Cup REAR WHEEL BEARINGS Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. Page 7941 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Page 3503 Throttle Position Sensor: Description and Operation TP Sensor Throttle Position Sensor (TPS) PURPOSE The Throttle Position Sensor (TPS) is a non-adjustable potentiometer that senses throttle angle and relays the information to the control module. This input to the control module is used to control the fuel system and most of the control module outputs. CONSTRUCTION The TPS has internally three circuits. One to ground, the other from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage . As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). OPERATION As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation movement to the TP sensor. A potentiometer (variable resistor) within the Throttle Position (TP) sensor assembly changes its resistance in proportion to throttle movement. If the TP sensor senses a Wide Open Throttle (WOT) a voltage signal indicating this condition is sent to the control module. The control module then increases the injector base pulse width, permitting increased fuel flow. LOCATION The non-adjustable Throttle Position (TP) sensor, is mounted on the side of the throttle body opposite the throttle lever assembly. Page 382 Cruise Control Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 7103 8. In any case, once the proper repairs have been made, the final step in the repair process involves polishing the vehicle. A WORD ABOUT CLEARCOAT THICKNESS The clearcoat on the vehicle is typically 1.5 to 2.0 mils thick (one mil equals .001" or 1/1,000 of an inch). At least one mil thickness is required to provide lasting protection to the vehicle basecoat. PAINT GAGES The best way to accurately measure how much clearcoat has been removed is to use a paint gage before, during and after the sanding process. Paint gages measure the total thickness of the finish and when used, can determine how much clearcoat has been removed during the repair process. Paint gages range from magnetic pull types to sophisticated electronic types, are available from a variety of sources, and can cost from $30 to $1800. The older magnetic type gages, at best, a +/- 5% accuracy range and are not sensitive enough to detect removal of .5 mil clearcoat. The newer type magnetic gages have improved accuracy ranges. Most gages are confined to checking either a ferrous metal (steel) or non-ferrous metal (aluminum) panels. At this time, there are no viable gages for reading film thickness on non-metallic panels. A more sophisticated gage is the digital Elcometer 300 fn Paint Thickness gage (or equivalent). It has an ability to read film thickness on both ferrous and non-ferrous metal panels. This instrument has an accuracy range of +/- 1% and has thickness standards included for recalibration. Approximate cost = $1750. An alternative (for use on steel panels only) would be the digital Elcometer 246 model, or equivalent. This gage has a +/- 3% accuracy range and include thickness standards for recalibration. Approximate cost - $575. REPAIRING RAIL DUST DAMAGE Rail dust damage comes from the tiny iron particles produced from the friction between the train wheels and the track. It can also be deposited on vehicles if stored near any operation producing iron dust (steel ore yards, etc.). This dust can either lay on top of, or embed into the paint surface. It is usually diagnosed as; bumps in the paint surface OR - rust colored spots in the paint. PROCEDURE: 1. Wash the vehicle with soap and water, dry it and clean the affected area with wax and grease remover. 2. Keeping the vehicle in a cool or shaded area, rinse the surface with cold water. CAUTION: RAIL DUST REMOVER (OXALIC ACID) IS AN ACIDIC SUBSTANCE CONTAINING CHEMICALS THAT WILL BREAK DOWN THE IRON PARTICLES EMBEDDED IN THE FINISH. WHEN WORKING WITH IT, USE THE NECESSARY SAFETY EQUIPMENT, INCLUDING GLOVES AND GOGGLES. FOLLOW THE MANUFACTURER'S DIRECTIONS CLOSELY BECAUSE IT MAY REQUIRE SPECIAL HANDLING AND DISPOSAL. 3. Soak several terry cloth towels in a container of rail dust remover solution and, after the damaged areas have been rinsed with cold water, lay the wet towels on the damaged areas. 4. Allow the towels to remain in place for 20 minutes, keeping them moist by spraying with water and not allowing to dry on the surface of the vehicle. 5. After 20 minutes of applying the towels, remove them and rinse the area thoroughly with cold water. Inspect the affected area to ensure the dust has been removed. Use both touch (feeling for bumpy surface) and sight (magnifying glass for close inspection). 6. If upon inspection some particles are still present, the process of applying the towels can be repeated 3 times. 7. Select a test area and hand wet sand with American ultra fine 1,500 grit to 2,000 grit sandpaper to repair damage (surface pitting from dust). a. Use ample amounts of water. b. Go slow to prevent removing too much clearcoat. NOTICE: USE A PAINT GAGE TO DETERMINE THE AMOUNT OF CLEARCOAT REMOVED. IF TOO MUCH HAS BEEN REMOVED, ADDITIONAL CLEARCOAT WILL HAVE TO BE APPLIED. IF RAIL DUST HAS PENETRATED INTO THE BASECOAT, THE PANEL REQUIRES REFINISHING. MAKE SURE ALL RAIL DUST HAS BEEN REMOVED PRIOR TO REFINISHING OR THE RUST SPOTS WILL RETURN, CAUSING CUSTOMER COMEBACKS. 8. If the damage has been repaired, complete the repair to the entire panel. 9. Once the damage has been repaired, the final step in the repair process involves polishing the vehicle. PREVENTING INDUSTRIAL FALLOUT DAMAGE Customers should be urged to wash and dry their vehicles frequently and garage them, or at least cover them with a quality car cover when not in use. Fuel - Top Tier Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel - Top Tier Detergent Gasoline Information Bulletin No.: 04-06-00-047 Date: June 24, 2004 ADVANCED SERVICE INFORMATION Subject: Top Tier Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) Models: 2005 and Prior All General Motors Passenger Cars and Trucks (U.S. Only) A new class of gasoline, called Top Tier Detergent Gasoline, will be appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by four automotive companies. A description of the concept and benefits of Top Tier is provided in the following question and answer section. What is Top Tier Detergent Gasoline? Top Tier Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by four automotive companies that exceed the detergent requirements imposed by the EPA. Who developed Top Tier Detergent Gasoline standards? Top Tier Detergent Gasoline standards were developed by four automotive companies: BMW, General Motors, Honda and Toyota. Why was Top Tier Detergent Gasoline developed? Top Tier Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet Top Tier Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, Top Tier was developed to give fuel marketers the opportunity to differentiate their product. Why did the four automotive companies join together to develop Top Tier? All four corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of Top Tier Detergent Gasoline? Top Tier Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of Top Tier Detergent Gasoline will help reduce deposit related concerns. Who should use Top Tier Detergent Gasoline? All vehicles will benefit from using Top Tier Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from use of Top Tier Detergent Gasoline. Where can Top Tier Detergent Gasoline be purchased? The Top Tier program began on May 3, 2004. Some fuel marketers have already joined and are making plans to introduce Top Tier Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, a list of all fuel marketers meeting Top Tier standards will be made available. For now, look for the "Top Tier" designation at the gas pump. Disclaimer Page 7225 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Specifications Brake Caliper: Specifications Caliper Mounting Bolt 37 ft.lb Page 4119 Fig. 11 Check Ball Location. Page 6293 2. Place the Temperature and Mode controls in the upper position. 3. Apply thumb pressure to each of these control knobs to hold them in the upper position while using a small screw driver to pry off the knobs (Figure 1). 4. Use the same procedure to remove the blower switch knob. 5. Disconnect the 2 light sockets from the housing by twisting the sockets counterclockwise. Body & Frame - Misalignment of Pickup Box to Cab Truck Bed: Customer Interest Body & Frame - Misalignment of Pickup Box to Cab Number: 93-91-10 Section: 10 Date: JAN. 1993 Corporate Bulletin No.: 261514 ASE No.: B1 Subject: MISALIGNMENT OF PICKUP BOX TO CAB Model and Year: 1982-93 S/T TRUCKS Some owners of 1982-1993 S/T pickups may comment about misalignment of the pickup box to the cab. CAUSE: Misalignment may occur as a result of the frame mounting hole not allowing side to side adjustment. CORRECTION: To correct, it is necessary to enlarge the left front hole on the frame at the front of the pickup box and realign the box to the cab. SERVICE PROCEDURE: 1. Loosen all of the pickup box to frame bracket mounting bolts. Remove only the left corner bolt. 2. Raise and support the front left corner of the box approximately one inch (1"). 3. Drill, from the bottom up, the left front hole in the frame mounting bracket enlarging the hole to approximately 17 mm (11/16") ID. 4. Lower the box and loosely reinstall the left front corner mounting bolt. 5. Align the box to the cab body. Torque all the box to frame bracket mounting bolts 40-54 N-m (30-40 lbs.ft.). WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B5300 Use applicable labor time guide for labor hours. Page 5170 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Locations Cruise Controller: Locations Cruise Control Components, Near Steering Column. Under LH Side Of I/P Page 4795 Brake Master Cylinder: Tools and Equipment BASIC SERVICE (Removal and Installation) - Fender cover (servicing and bleeding a master-cylinder can be a messy process) CAUTION: DOT 3 or 4 brake fluid is very corrosive to the vehicles finish and electrical connections. - Drip pan. - Complete set of combination wrenches or sockets. - Bleeding device: - Pressure bleeder or - Vacuum bleeder or - One-man brake bleeder kit or - Length of clear plastic hose (3/16 inch ID) and a glass jar. Brake Bleeding Setup - Small ruler or depth gauge (for adjusting the pushrod) - Brake adjusting tool (rear brake adjustment should be checked) - Clean shop towels. OPTIONAL - Master Cylinder bleeding kit (contains plastic fittings and hoses used for bleeding master cylinders) - Suction bulb (for removing brake fluid from reservoir) IF MASTER-CYLINDER IS OVERHAULED - Snap-ring pliers - Small pry bar (for separating the reservoir from the cylinder) - Cylinder hone (cast iron cylinders only) - Feeler gauges (for checking piston to cylinder clearance). Page 590 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature (ECT) Sensor Engine Coolant Temperature (ECT) W Engine Wiring, RH Side Bendix Brake Boosters Hydraulic Brake Booster: Service and Repair Bendix Brake Boosters Hydro-Boost Assembly DISASSEMBLY Fig. 2 Removing Accumulator Fig. 3 Typical Hydro-Boost Unit Disassembled 1. Place accumulator compressor tool No. J-26889 or equivalent, around the end of accumulator, and install nut onto stud as shown in Fig. 2, then depress the accumulator with a C-clamp. 2. Remove retainer by using a suitable punch. 3. Release the C-clamp and remove accumulator compressor tool No. J-26889 or equivalent. 4. Remove accumulator, O-ring, retainer, plug and spring as shown in Fig. 3. 5. Remove retainer, output pushrod, baffle, piston return spring and retainer. 6. With a suitable saw, cut off the eyelet of the pedal rod, then remove the boot. 7. Remove nut, bracket and bolts, then separate cover from housing. 8. Remove piston assembly and seals. 9. Remove spool valve, then with a wire hook remove accumulator valve. 10. Remove return line fitting and seal. Page 8562 Figure 7 Figure 8 Figure 9 Figure 10 Page 6127 Compressor Clutch: Specifications With HR6-HE Compressor Clutch Plate & Rotor .............................................................................................................................................................. 0.50-0.76mm (0.020-0.030") Single Diaphragm Type Vacuum Brake Booster: Description and Operation Single Diaphragm Type Fig. 1 Exploded View Of Delco-Moraine Single Diaphragm Power Brake Unit Fig. 2 Exploded View Of Delco-Moraine Single Diaphragm Power Piston Assembly DESCRIPTION These power brake units, Figs. 1 and 2, are a combination vacuum-hydraulic brake booster of the vacuum suspended type which use engine intake manifold vacuum and atmospheric pressure for its power. These units consist of a vacuum power section and an hydraulic master cylinder section. The vacuum power section contains a power piston with rolling diaphragm mechanism and power piston return spring. The control valve is made up of an air valve and floating vacuum control valve assembly. The reaction mechanism consists of an hydraulic piston, reaction plate and a series of levers. The valve operating rod, which operates the air valve, projects from the power section and is connected to the brake pedal linkage. Page 526 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 3574 Distributor And Coil 4.3W Page 8572 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 2310 Heater Core: Service and Repair Heater Hose Replacement HEATER HOSE REPLACEMENT Engine Heater Hose Routing (w/ Air Conditioning) The heater inlet hose is routed from the intake manifold to the inlet pipe of the heater core. The heater outlet hose is routed from the outlet pipe of the heater core to the inlet fitting of the coolant pump. Hoses are attached at each end with screw-type clamps. REMOVE OR DISCONNECT 1. Engine coolant. - Drain enough coolant into a clean container to lower the coolant level below the level of the lowest heater hose fitting. 2. Inlet and outlet hoses (72 and 70) at fittings. - Loosen the clamp screws enough to slide the clamps away from the fittings on the inlet and outlet hoses (72 and 70). - Remove the hose end by twisting and pulling. NOTICE: The heater core can be damaged if too much force Is applied on the core tubes During removal If the heater hose will not come off easily, cut off the hose forward of the heater core tube. Cut the hose remaining on the core tube lengthwise to remove it. 3. Hose Support clamps, brackets and/or retainers, as necessary. 4. Heater hose(s) (72 and 70) and clamps. INSTALL OR CONNECT 1. Healer hose(s) (72 and 70) and clamps. 2. Hose support clamps, brackets and/or retainers, if removed. 3. Inlet and outlet hoses (72 and 70) to fittings. - Apply rubber lubricant to the inside diameter of hose ends, If desired. - Slip a new hose clamp over one end of the hose and push the hose onto the heater pipe with a twisting motion. - Repeat the hose and clamp installation procedure at the other end of the hose. - Tighten clamp screw to 1.7 Nm (15 in. lb.). 4. Engine coolant. - Use the coolant drained earlier only if it is uncontaminated. Discard contaminated coolant and add fresh 50/50 coolant and water mixture. Aluminum Wheels - Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Locations Steering Column Page 7595 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 5308 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 8116 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 1205 ^ PAG oil used for future service if needed (mark PAG on box on label, Figure 6). ^ HR6 or R4 original compressor RETAINED - add 8 oz FAG oil to system ^ V5 original compressor RETAINED - add 9 oz V5 Retrofit oil to system. If V5 Retrofit oil is not available from GMSPO, REPLACE THE COMPRESSOR. c. Based on the above chart, add oil if needed. Use the new oil bottle and the extended tube kit, J 39500-71. Fill the bottle with at least 10 oz of oil. Attach the new bottle to the back of the ACR4, and open the oil fill valve. Allow the correct amount of oil to be drawn into the system. DO NOT allow the oil level to drop below the end of the pickup tube. This will prevent any air from being drawn into the system. If any oil was removed during the R-12 recovery evacuation steps, DO NOT add additional oil to replace it. d. Determine the correct amount of R-134a to use. Check the existing label of the vehicle for the R-12 charge amount. Use the formula {(R12 x .9) - .25 lb = R-134a} to determine the correct charge. This can also be stated as: Take 90% of the R12 charge, and subtract 1/4 lb. Follow the directions for the ACR4 cart to recharge the system. At the end of the process, "CPL" will be displayed. Close the high side valve. e. Start the vehicle, turn on the A/C system, and confirm that pressures are within normal operating ranges, as shown in the 1994 Service Manual. The 1994 Service Manuals can be used as a reference for diagnosis and specification of retrofitted systems. On some vehicles with automatic A/C controls or low charge diagnostics, the A/C compressor may not engage if any diagnostic codes were set during the retrofit. Check to see if any codes were set in either the HVAC or Engine Control systems. If they were, clear the codes following the directions in the Service Manual. Page 7404 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Diagram Information and Instructions Clutch Switch: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 6763 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 1757 Valve Spring: Specifications Free Length Outer Spring 2.03 in Damper Spring 1.86 in Out Of Square Limit 0.062 in Installed Height 1.687-1.750 in Initial Inspection and Diagnostic Overview Engine Control Module: Initial Inspection and Diagnostic Overview Diagnostic Circuit Check Page 7684 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 1297 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 3726 CHANGES TO MEMCAL/PROM LABELING FORMATS ^ MEMCALs may use either INK-JET or ADHESIVE labels, as shown. ^ PROMs will always use ADHESIVE labels with the same format as shown for MEMCALs. These changes will become effective on parts manufactured after 10/94. Page 5188 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 4315 Pinion Gear: Adjustments Timken/Rockwell - 12 Inch Ring Gear Fig. 1 Timken/Rockwell drive axle w/12 inch ring gear exploded view DISASSEMBLY 1. Tap or press pinion from cage, taking care not to damage shaft threads, then remove outer pinion bearing, Fig. 1. 2. Remove spacer from pinion, then the inner bearing, using suitable separator and press or puller. 3. If straddle bearing must be replaced, remove snap ring and washer, then the bearing, using suitable puller. 4. If bearings are to be replaced, press outer races from bearing cage, taking care not to distort cage. 5. Inspect components as outlined, and replace as needed, keeping components in order for assembly. ASSEMBLY & PRELOAD ADJUSTMENT 1. When installing new cups, press them firmly against pinion bearing cage shoulders. 2. Lubricate bearings and cups with suitable lubricant. 3. Press rear thrust and radial bearings firmly against pinion shoulders, using suitable sleeve that will bear only on bearing inner race. 4. Install radial bearing lock ring, then squeeze ring into pinion shaft groove. 5. Insert pinion and bearing assembly in pinion cage and position spacer or spacer combination over pinion shaft. 6. Press front bearing firmly against spacer. Tailgate - Latch Rattle, Revised Striker & Latch Trunk / Liftgate Latch: Technical Service Bulletins Tailgate - Latch Rattle, Revised Striker & Latch Number: 92-153-10 Section: 10 Date: APRIL 1992 Corporate Bulletin No.: 161514 ASE No.: B1 Subject: END GATE LATCH RATTLE Model and Year: 1983-92 S/T TRUCKS Owners of some 1983-1992 S/T 2 and 4 door utility vehicles may comment that their end gate latch rattles. One possible cause of this condition is the end gate latch fork bolts contacting the striker assembly (metal-tometal) causing a rattle. To correct this condition, it is necessary to install a new striker assembly that has a urethane sleeve over the striker post. The urethane sleeve preventsmetal-to-metal contact and may eliminate the rattle. SERVICE PROCEDURE: Specifications Vacuum Reservoir HVAC: Specifications Vacuum Tank Mounting Screw ............................................................................................................ ................................................... 3 Nm (27 in. lbs.). Page 7534 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 4954 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7203 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT A/T - Early Converter Clutch Engagement Torque Converter Clutch: All Technical Service Bulletins A/T - Early Converter Clutch Engagement Number: 92-75-7A Section: 7A Date: JAN. 1992 Corporate Bulletin No.: 137107 ASE No.: A2 Subject: EARLY TRANSMISSION CONVERTER CLUTCH APPLY Model and Year: 1992 S/T TRUCKS WITH 4.3L ENGINE AND 4L60 AUTOMATIC TRANSMISSION Condition: Some owners of 1992 S/T trucks with 4.3L (LB4) engines and automatic transmissions may comment on early transmission converter clutch (TCC) engagement, TCC engagement just after the 2-3 upshift, or lack of power. Cause: The torque converter clutch is applied at low speeds during some driving conditions. Correction: To correct this condition install a new calibration PROM which raises the TCC apply speed. This calibration will increase the TCC apply speed on a 1992 vehicle to be similar to a 1991 vehicle. (See below) Part PROM Scanner Number Application Broadcast I.D. 16175285 Federal BARL 5551 16175286 California BARM 5561 Parts are expected to be available on January 27, 1992. In case of limited inventory, parts will be placed on 400 Control to waive VIP surcharges. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation at dealer's expense and all other order types will be placed on backorder until the 400 control is removed. Labor Operation Number: T0500 Labor Time: 0.8 Hour Page 4875 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 4945 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 1595 Compression Check: Testing and Inspection COMPRESSION CHECK - Disconnect the primary terminal from the ignition coil. - Remove all spark plugs. - Block the throttle plate wide open. - Make sure the battery is fully charged. Starting with the compression gauge at zero, crank the engine through four compression strokes (four "puffs"). - Make the compression check at each cylinder and record each reading. - If some cylinders have low compression, inject 15 ml (one table spoon, or 3 squirts from a pump type oil can) of engine oil into the combustion chamber through the spark plug hole. - Minimum compression recorded in any one cylinder should not be less than 70 percent of the highest cylinder, and no cylinder should read less than 690 kPa (100 psi). Normal Compression: Compression builds up quickly and evenly to specified compression on each cylinder. Piston Rings Leaking: Compression low on first stroke, tends to build up on following strokes, but does not reach normal. Improves considerably with addition of oil. Valves Leaking: Low on first stroke. Does not tend to build up on following strokes. Does not improve much with addition of oil. Head Gasket Leakage: If two adjacent cylinder have lower than normal compression, and injecting oil into cylinders does not increase the compression, the cause may be a head gasket leak between the cylinders. Page 2898 ECM QDR Check Procedure Page 6718 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 7136 Seat Cover: Technical Service Bulletins Leather Seat Covers - Cleaning Procedure File In Section: 10 - Body Bulletin No.: 43-16-06 Date: October, 1994 Subject: Cleaning Procedure for Leather Seat Covers Models: 1995 and Prior Passenger Cars and "C/K" and "S/T" Trucks If leather seat covers are being returned only because they are dirty, a more aggressive cleaning procedure is recommended by General Motors prior to replacing covers. Procedure Dirty or soiled leather seat covers should be cleaned with a mild soap and water solution, using clean soft cloths. When this procedure proves inadequate, a commercially available leather cleaner, "Tanner's Preserve Leather Cleaner"* should be used with a 3M "Type T"* scrubbing pad. Important: The type of scrubbing pad is very critical because the common 3M Scotch-Brite green pad is too aggressive and will damage the leather finish. The cleaner is available from "First Brands" by calling 1-800-726-1001, identifying yourself as a GM dealership, requesting "Tanner's Preserve Leather Cleaner" product, number AS-330, quantity and shipping address. This product is also available at stores. The 3M "Type T" scrubbing pad is available from a 3M distributor. Call 1-800-742-9546 for the nearest distributor and then request the Scotch-Brite Clean and Finish Sheet, "Type T", in 6 x 9 inch sheets, UPC code number 048011-01276. * We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Brake Light Switch Brake Light Switch: Locations Brake Light Switch Cruise Control I/P Wiring Page 338 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7210 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 8359 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 4354 Axle Shaft Assembly: Service and Repair Dana/Spicer Full Floating Axle Axle Assembly REAR DRIVE AXLE 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Shaft Replace REAR DRIVE AXLE Fig. 3 Axle, Hub & Drum Components. 1. Using a soft faced mallet, tap axle shaft flange lightly to loosen shaft. 2. Remove axle shaft attaching bolts, Fig. 3, then grip axle shaft rib with pliers and twist to start shaft removal. 3. Remove axle shaft from axle tube. 4. Reverse procedure to install. Wheel Bearing REAR WHEL BEARINGS 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Rockwell Full Floating Axle Differential Axle Housing: Service and Repair Rockwell Full Floating Axle 1. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Page 6129 Compressor Clutch: Specifications With SD-709 Compressor Clutch Hub Air Gap ....................................................................................................................................................... 0.49 - 0.79 mm (0.016 - 0.031 in.) Page 8529 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Cooling System - Coolant Recycling Information Coolant: Technical Service Bulletins Cooling System - Coolant Recycling Information Bulletin No.: 00-06-02-006D Date: August 15, 2006 INFORMATION Subject: Engine Coolant Recycling and Warranty Information Models: 2007 and Prior GM Passenger Cars and Trucks (Including Saturn) 2007 and Prior HUMMER Vehicles 2005-2007 Saab 9-7X Attention: Please address this bulletin to the Warranty Claims Administrator and the Service Manager. Supercede: This bulletin is being revised to adjust the title and Include Warranty Information. Please discard Corporate Bulletin Number 00-06-02-006C (Section 06 - Engine/Propulsion System). Coolant Reimbursement Policy General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words: if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of GM Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Licensed Approved DEX-COOL(R) Providers Important: USE OF NON-APPROVED VIRGIN OR RECYCLED DEX-COOL(R) OR DEVIATIONS IN THE FORM OF ALTERNATE CHEMICALS OR ALTERATION OF EQUIPMENT, WILL VOID THE GM ENDORSEMENT, MAY DEGRADE COOLANT SYSTEM INTEGRITY AND PLACE THE COOLING SYSTEM WARRANTY UNDER JEOPARDY. Shown in Table 1 are the only current licensed and approved providers of DEX-COOL(R). Products that are advertised as "COMPATIBLE" or "RECOMMENDED" for use with DEX-COOL(R) have not been tested or approved by General Motors. Non-approved coolants may degrade the Page 6610 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Tires - Speed Rated Information Tires: All Technical Service Bulletins Tires - Speed Rated Information Group Ref.: 3 - Steering/Suspension Bulletin No.: 433502 Date: July, 1994 INFORMATION SUBJECT: SPEED RATED TIRES MODELS: 1995 AND PRIOR YEAR PASSENGER CARS AND LIGHT DUTY TRUCKS All original equipment passenger car and light duty truck tires used by General Motors have a speed rating symbol molded on their sidewall. This speed symbol, along with the tire's load index, make up the service description that follows the tire's size. The original equipment tire size, speed rating, and recommended inflation pressure are listed on the tire placard usually located on the driver's door edge. WHEN REPLACING TIRES, NEVER INSTALL A TIRE THAT IS A SMALLER SIZE OR LESSER SPEED RATING THAN THAT USED AS ORIGINAL EQUIPMENT. As in the past, it is recommended that replacement tires have a TPC (Tire Performance Criteria) number on the sidewall that is identical to that on the original tires. Common speed rating on tires used by General Motors are as follows: (see illustration) IMPORTANT: Most base all season tires and touring tires used by GM are S rated. Performance tires will usually have a higher speed rating. High performance tires are usually Z rated. Z rated tires carry the Z symbol within the tire size, rather than after the size in the service description. These speeds apply only at the tire's full pressure. An underinflated tire will not meet its speed rating capability. Speedometer - Registers When Vehicle is Stationary Vehicle Speed Sensor: All Technical Service Bulletins Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. Page 4733 from contacting these areas. Clean any fluid that may drip onto wheel cylinders or calipers to prevent corrosion. Always re-seal and wipe off brake fluid containers to prevent spills. Tools Required: J 39177 Valve Pressure Bleeding Tool (three required) Note: You can also use a modified J 35856 Valve Pressure Bleeding Tool providing you remove the dimple from it first. J 29567 Universal Brake Bleeder Adaptor (use for pressure bleed) J 29532 Diaphragm Type Brake Bleeder (brake fluid pressure tank for pressure bleed) TK 00000 Tech-1 Scan Tool TK 02650 RWAL/4WAL Cartridge Kit (include proper cable/adaptor), or 7000001 Mass Storage Cartridge Kit (include proper cable/adaptor) 3000003 Mass Storage Cartridge (include proper cable/adaptor) MANUAL BLEED PROCEDURE When a pressure bleeder is not available, use the (two person) manual bleed procedure. One person will push on the brake pedal while the other person will open and close the bleed valves. Important You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Begin by opening the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (Figure 2). 2. Attach the valve pressure bleeding tool J 39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (Figure 3). Tighten tool J 39177 only finger tight. Note: It is not necessary to attach bleeding tool J 39177 to the combination valve when using the manual bleed procedure. 3. Bleed each wheel in the following sequence: Page 7331 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 595 EGR AND EVRV SOLENOID 4.3 L Page 6557 EMC TROUBLESHOOTING CHART 1. Transceiver Location Refer to the attached figures during installation. 1. Transceiver Location Page 7671 Figure 7 Figure 8 Figure 9 Figure 10 Page 6569 Driver Information Center (DIC): Symptom Related Diagnostic Procedures Check Gages Indicator Does Not Light With High Coolant Temperature - Gage OK Check Gages Indicator Does Not Light With Low Oil Pressure - Gage OK Cluster Display Does Not Dim With Lights On Cluster Display Does Not Light Page 6876 1. With the end gate open, use a grease pencil to mark around the circumference of each washer (Figure 1, "7") located behind the strikers. 2. Unscrew and remove the existing striker assemblies (Figure 1, "6") from the vehicle. 3. Loosely assemble the new striker (Figure 1, "6") (P/N 15700881) and washer (Figure 1, "7") and reinstall using the pencil marks as a guide. 4. Install the striker assemblies (Figure 1, "6") using a T50 Torx(R). Torque to 63 N-m. (47 lbs.ft.). 5. Check for proper operation and end gate flushness. Adjust the striker assemblies if required. The end gate lock strikers can be adjusted up or down, fore or aft, to obtain proper closure of the end gate. The end gate should seal completely with minimum closing effort. Torque the striker bolts to 63 N-m. (47 lbs.ft.). SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY/VEH 15700881 Striker Asm. 2 A/T - Harsh 1-2 Upshift, May Require Cold Soak Accumulator: Customer Interest A/T - Harsh 1-2 Upshift, May Require Cold Soak Number: 92-318-7A Section: 7A Date: NOV. 1992 Corporate Bulletin No.: 277135R ASE No.: A2 Subject: HARSH 1-2 UPSHIFT Model and Year: 1992 CAPRICE, CAMARO AND CORVETTE 1992 C/K, G, L/M, S/T TRUCKS TRANSMISSION APPLICATIONS: 1992 HYDRA-MATIC 4L60 TRANSMISSION MODELS: 2AAM, 2ACM, 2ADM, 2AKM, 2BAM, 2BBM, 2BCM, 2BHM, 2BRM, 2BWM, 2CAM, 2CBM, 2CCM, 2CFM, 2CHM, 2CJM, 2CPM, 2FTM, 2FUM, 2FZM, 2HBM, 2HDM, 2HLM, 2KHM, 2KJM, 2KMM, 2LHM, 2MDM, 2MJM, 2MSM, 2SHM, 2TAM, 2TBM, 2TLM, 2TWM, 2WAM, 2WBM, 2WCM, 2YAM, 2YCM SUBJECT: Harsh 1-2 Upshift; Install Service Package VEHICLE APPLICATIONS: B, F, Y Cars C/K, S/T Trucks G, L, M Vans CONDITION (Figure 1): Some vehicles equipped with a 1992 HYDRA-MATIC 4L60 transmission built between Julian Date 061 (March 1, 1992) and Julian Date 171 (June 19, 1992) may experience a harsh 1-2 upshift. NOTE: Once the transmission is brought to operating temperature, the condition may not be able to be reproduced until a "cold soak" (overnight) is performed. CAUSE: The above condition may be caused due to a tapered 1-2 accumulator sleeve. The tapered bore may cause the 1-2 accumulator valve to stick in the bottom of the bore. Page 7543 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 1434 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Page 6395 procedures and short-cutting refrigerant recycling times. Use the following procedure for testing and correcting air contamination in your A/C service equipment. 1. Make certain that the ACR4 equipment has not been used for at least 12 hours. It is recommended that the equipment be left in an area where the temperature will remain constant overnight to allow the temperature of the refrigerant in the tank to stabilize. 2. Record the surrounding air temperature next to the ACR4 refrigerant tank. Important: A major assumption is that the ambient air temperature next to the tank represents the refrigerant temperature in the tank. Failure to take care in measuring the temperature could result in unnecessary work. 3. Close both liquid (blue) and vapor (red) valves on the ACR4 tank. 4. Disconnect low side (blue) service hose from the back of the ACR4. 5. Slowly disconnect the tank vapor hose (red) from the back of the ACR4 and connect it to the low side service port. 6. Open the vapor (red) valve on the tank and record the tank pressure on the low side gage. 7. Restore hoses to the original position. 8. Referring to the Table, find the ambient temperature measured in Step 2. Compare the pressure reading from Step 6 to the "maximum allowable pressure". If the pressure reading from Step 6 is less than the "maximum allowable pressure", no further action is necessary. Important: The closer the tank pressure is to the desired tank pressure, the better the A/C system will perform. 9. If the pressure reading from Step 6 exceeds the maximum allowable pressure from the Table, open both tank valves and operate the ACR4 through 4 or 5 evacuation cycles. This will activate the automatic air purge to lower the tank pressure. Important: Station should not be connected to vehicle. 10. Repeat the tank pressure checking procedure the next day to determine if the pressure has been reduced to acceptable levels. If the tank pressure has been reduced but is not acceptable, cycle with ACR4 through more evacuation cycles and recheck the next day. Continue process until acceptable pressure is obtained. If the tank pressure is not reduced through the evacuation cycling, then Kent-Moore should be contacted at 1-800-345-2233. Page 4988 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 8494 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Restraints - Seat Belt Warning Lamp On/Buckling Issues Seat Belt Buckle: All Technical Service Bulletins Restraints - Seat Belt Warning Lamp On/Buckling Issues INFORMATION Bulletin No.: 09-09-40-001A Date: February 02, 2011 Subject: Seat Belt Buckle Latching Issues and/or Seat Belt Warning Lights Illuminated Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7 X Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 09-09-40-001 (Section 09 - Restraints). This bulletin is being published to advise dealers about seat belt buckles not operating and/or seat belt warning light illumination, as well as difficulty latching and unlatching the buckle or the buckle release button sticking. Analysis of warranty data has determined that this condition may be caused by sticky beverages being spilled onto or into the seat belt buckle assembly. Foreign debris from food, candy wrappers, paper and coins can also contribute to this condition. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise the customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. Important Never insert anything other than the seat belt latch plate into the buckle assembly. Do not attempt to dig anything out of a buckle with a tool. Never try to wash out a buckle to remove a spilled liquid as this may damage the buckle. Use the following steps to determine the cause of the concern. 1. Inspect the buckle assembly with a light shining on the latch plate insertion area. Look for any debris or foreign objects in the buckle. 2. If any debris or foreign objects are observed, try to vacuum out the item. After the foreign material is removed, latch and unlatch the seat belt. If the system functions properly, do not replace the seat belt buckle assembly. 3. If the condition has not been corrected, inspect the buckle assembly for any sticky residue. If sticky residue is found, inform the customer that a substance was spilled on the seat belt buckle assembly causing the malfunction. The buckle assembly will need to be replaced at the customer's expense. 4. Refer to SI for seat belt component replacement. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced at the customer's expense. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. 5. If further restraint diagnosis is required, refer to Seat Belt System Operational and Functional Checks in SI. Page 3489 Refer to the 1992 Light Duty Truck Service Manual, Fuel and Emissions Section, for proper accelerator pedal removal and installation. 2. Retest the TPS voltage. If the voltage readings for 4.3L (LB4) vehicles are still below the specified voltages, replace the accelerator cable with a redesigned cable (P/N 15693481). Refer to 1992 Light Duty Truck Service Manual, Fuel and Emissions Section, for proper accelerator cable removal and installation. SERVICE PARTS INFORMATION Part Number Description Application Quantity 15693481 Accelerator Control Cable S/T 1 (LB4 engine) 15679725 Accelerator Pedal Lever Asm. S/T 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Description Labor Operation Pedal, Accelerator - Replace J5350 Cable, Accelerator Control J5330 (Pedal to Lever) - Replace Use applicable labor time guide to labor hours. Locations Engine Wiring, LH Side Page 2290 RH Front Side Of Engine. RH Side Of Engine Block Applicable to: 1991 4.3L/V6-262 Engine, Bravada Page 300 Brake Vacuum Release Valve: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 3369 Page 8358 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 5408 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 6691 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 8354 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 6710 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer TCC Solenoid Rear Of Engine Cruise Control - Works Intermittently Cruise Control Switch: Customer Interest Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Technician Safety Information Hose/Line HVAC: Technician Safety Information WARNINGS: - Air conditioning systems contain Refrigerant-12. This is a special mixture which requires special handling procedures to avoid personal injury. - Always wear goggles and wrap a clean cloth around fittings, valves, and connections when performing work that involves opening the refrigerant system. - Always work in a well ventilated area and avoid breathing any refrigerant fumes. - Do not weld or steam clean on or near any vehicle-installed air conditioning lines or components. - If Refrigerant-12 should come in contact with any part of the body, flush the exposed area with water and immediately seek medical help. CAUTIONS: - All Refrigerant-12 drums are shipped with a heavy metal screw cap. The purpose of the cap is to protect the valve and safety plug from damage. It is good practice to replace the cap after each use of the drum. - If it is necessary to transport or carry any container of Refrigerant-12 in a vehicle, do not carry it in the passenger compartment. - See the manufacturer's guide-lines for storage, transportation and the maximum temperature to which the container can be exposed. - If the occasion ever arises to fill a small Refrigerant-12 drum from a large one, never fill the drum completely. Space should always be allowed above the liquid for expansion. Page 7272 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 5469 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7974 Oil Pressure Sender: Locations Engine Sensor Locations. Top Rear Of Engine Applicable to: Except 4.3L/V6-262 HP & 4.3L/V6-262 Turbo Engines Page 2978 CMFI Intake Manifold Sensors/Valves Page 5276 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 8263 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Locations Rear Door Power Window Page 3113 Engine Wiring, LH Side Engine - Intake Manifold Inspection/Replacement Intake Manifold: Technical Service Bulletins Engine - Intake Manifold Inspection/Replacement INFORMATION Bulletin No.: 00-06-01-026C Date: February 03, 2010 Subject: Intake Manifold Inspection/Replacement After Severe Internal Engine Damage Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to include additional model years. Please discard Corporate Bulletin Number 00-06-01-026B (Section 06 - Engine). When replacing an engine due to internal damage, extreme care should be taken when transferring the intake manifold to the new Goodwrench service engine long block. Internal damage may result in the potential discharge of internal engine component debris in the intake manifold via broken pistons and/or bent, broken, or missing intake valves. After removing the intake manifold from the engine, the technician should carefully inspect all of the cylinder head intake ports to see if the valve heads are still present and not bent. Usually when the valve heads are missing or sufficiently bent, internal engine component debris will be present to varying degrees in the intake port of the cylinder head. If this debris is present in any of the cylinder head intake ports, the intake manifold should be replaced. This replacement is required due to the complex inlet runner and plenum configuration of most of the intake manifolds, making thorough and complete component cleaning difficult and nearly impossible to verify complete removal of debris. Re-installation of an intake manifold removed from an engine with deposits of internal engine component debris may result in the ingestion of any remaining debris into the new Goodwrench service engine. This may cause damage or potential failure of the new service engine. Disclaimer Page 2782 Engine Control Module: Service and Repair Engine Control Module (ECM) Replacement When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure. 1. Disconnect battery ground cable. 2. Remove right side kick panel, then disconnect two ECM electrical connectors. 3. Remove ECM mounting hardware. 4. Remove ECM from passenger compartment. 5. Reverse procedure to install. Page 6433 being done. Important: During 1996, "oil-less" compressors began to be serviced with NO added oil. New part numbers will be issued, and both the box and the compressor will be clearly marked to indicate that no oil is present. If you receive one of these newer compressors, simply add the normal amount of oil to the system in Step 5 of the retrofit procedure (8 oz of PAG oil, or 9 oz of PAG oil with V5 compressor). These "oil-less" compressors are compatible with EITHER R12 or R-134a. Geo Models Compressors DO NOT HAVE TO BE REPLACED as part of the retrofit. New compressors are shipped with enough oil to accommodate the entire A/C system. Do not add additional PAG oil to the system it the compressor is being replaced. 1985-88 Nova, 1989-93 Prizm (S) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Loosen evaporator to compressor (suction) pipe (to be reinstalled) c. 1985-92 only: Loosen compressor to condenser (compressor discharge) pipe (to be reinstalled). d. 1985-88 only: Service Valve & Extension Housing on compressor (to be installed). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. 1985-88 only: Service Valve & Extension Housing on compressor using new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe 0-ring. e. 1985-92 Compressor to condenser (discharge) hose 0-ring. f. Receiver/dryer and 0-rings. R-134a amount: 85-92 - 650 grams (1.43 lb) 93 - 700 grams (1.54 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-88 - 94855761 89-93 - 94855762 Adapter Fittings: Low Side - 94855760 High Side - 94855759 0-Rings: 85-88 Compressor - Small 0-rings (6 required) - 94857336 - Large 0-ring - 94857337 85-93 Receiver/Dryer (2) - 94845949 Page 6690 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 88 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 5973 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Page 3483 Throttle Body: Service and Repair Fuel Meter Cover Assembly WARNING: DO NOT remove the four screws securing the pressure regulator to the fuel meter cover. The fuel pressure regulator includes a large spring under heavy compression which, if accidently released, could cause personal injury. Disassembly might also be result in a fuel leak between the diaphragm and the regulator container. NOTE: The fuel meter cover assembly contains the fuel pressure regulator assembly. The regulator has been adjusted at the factory and should only be serviced as a complete assembly. Fuel Meter Cover (TBI) REMOVAL: 1. Disconnect electrical connectors to fuel injectors. (Squeeze plastic tabs and pull straight up). 2. Remove long and short meter cover screw assemblies. 3. Remove fuel meter cover assembly. NOTE: DO NOT immerse fuel meter cover (with pressure regulator) in cleaner, as damage to regulator and gasket could occur. 4. Remove fuel meter outlet gasket and pressure regulator seal. Discard old gaskets and seal. INSPECTION: - Inspect for dirt, foreign material and casting warpage. INSTALLATION: 1. Install a new pressure regulator seal, fuel meter outlet passage gasket, and cover gasket. 2. Install fuel meter cover assembly. 3. Install attaching screw assemblies, precoated with appropriate locking compound to threads. (Short screws are next to injectors.) Tighten screw assemblies to 3.0 Nm (28.0 lb-in). 4. Reconnect electrical connectors to fuel injectors. 5. With engine "OFF" and ignition "ON", check for leaks around gaskets and fuel line couplings. Page 8313 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 860 What corrected the customer concern and was the repair verified? Please Explain: ............. Disclaimer Page 8391 Symbol Identification Page 7319 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 6174 Compressor Clutch: Service and Repair With SD-709 Compressor Compressor Components Remove or Disconnect Tool Required: J 4245 Internal Snap Ring Pliers J 6435 External Snap Ring Pliers J 8433 Puller Set J 37825 Puller Plate Assembly J 37827 Puller Pilot J 37828 Puller Fingers J 37872 Spanner Wrench Removing The Nut - Insert the two pins of the J 37872 into any two threaded holes of the clutch front plate (2). Hold the clutch plate stationary. Chevrolet Full Floating Axle Shaft Assembly: Description and Operation Chevrolet Full Floating Fig. 5 Full floating rear axle The straddle mounted drive pinion is supported at the front by two opposed tapered roller bearings. The pinion gear roller bearing consists of an outer race and roller assembly and a precision ground diameter on the pinion pilot functions as an inner race. On units with 10-1/2 inch ring gear, Fig. 5, side bearing preload and ring gear to pinion backlash are controlled by side bearing adjusting rings threaded into the carrier. Pinion depth is controlled by a shim located between the pinion bearing retainer assembly and axle housing. Page 8360 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 6194 4. Hold the J 33020 Puller in place and tighten the puller screw against the Puller Guide to remove the pulley rotor and bearing assembly (Fig. 17). 5. To prevent damage to the pulley rotor during bearing removal, the rotor hub must be properly supported. 5. To prevent damage to the pulley rotor during bearing removal, the rotor hub must be properly supported. Remove the forcing screw from J 33020 Puller and with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks as shown in Figure 18. 6. Drive the bearing out of the rotor hub with Rotor Bearing Remover J 9398-A and J 29886 Universal Handle (Fig. 18). It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will be necessary to file away the old stake metal (Fig. 21) for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Page 6864 11. Install cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time B1717 Replace Use Published Labor Hood Hinge Operation Time Page 6223 Compressor Clutch Hub: Specifications With V5 Compressor Clutch Plate & Rotor Air Gap ................................................................................................................................................ 0.50-0.076mm (0.20-0.030") Page 6047 Evaporator And Blower Case Replacement The accumulator assembly has a service replacement kit which includes two seals (O-rings) for the inlet and outlet connections. The desiccant is NOT serviced separately-it is part of the sealed accumulator assembly. Refer to A/C System Oil Charge Replenishing / "Refrigerant Oil Distribution" for presence of refrigerant oil and service conditions when removing the accumulator from the vehicle to measure the oil. See: Service and Repair Replace the accumulator when: 1. A physical perforation produces a leak. 2. The (orifice) screen experiences continued or repeated plugging. REMOVE OR DISCONNECT 1. Discharge and recover refrigerant from the system. 2. Evaporator (10) from accumulator (6) (figure 36). 3. Compressor hose assembly (3) from accumulator (6). 4. O-rings. - Cap or plug the open lines. 5. Electrical connections, as necessary. 6. Screw (38) and bracket (40). 7. Accumulator (6). - Install sealing caps if accumulator is not being replaced. INSTALL OR CONNECT 1. Accumulator (6). Refer to A/C System Oil Charge Replenishing / "Refrigerant Oil Distribution" if replacing accumulator. See: Service and Repair NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 2. Bracket (40) and screw (38) (figure 36). Page 138 Relay Box: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. A/T - No Movement in Drive or 3rd Gear Clutch: All Technical Service Bulletins A/T - No Movement in Drive or 3rd Gear TECHNICAL Bulletin No.: 08-07-30-027 Date: June 04, 2008 Subject: No Movement When Transmission is Shifted to Drive or Third - Normal Operation When Shifted to Second, First or Reverse (Replace Forward Sprag Assembly) Models: 1982 - 2005 GM Passenger Cars and Light Duty Trucks 2006 - 2007 Buick Rainier 2006 Cadillac Escalade, Escalade ESV, Escalade EXT 2006 Chevrolet SSR 2006 - 2008 Chevrolet Avalanche, Colorado, Express, Silverado Classic, Silverado, Suburban, Tahoe, TrailBlazer 2006 GMC Yukon Denali, Yukon Denali XL 2006 - 2008 GMC Canyon, Envoy, Savana, Sierra Classic, Sierra, Yukon, Yukon XL 2006 Pontiac GTO 2006 - 2007 HUMMER H2 2006 - 2008 HUMMER H3 2006 - 2008 Saab 9-7X with 4L60, 4L60E, 4L65E or 4L70E Automatic Transmission (RPOs MD8, M30, M32, M33 or M70) Condition Some customers may comment that the vehicle has no movement when the transmission is shifted to DRIVE or THIRD position, but there is normal operation when it is shifted to SECOND, FIRST or REVERSE position. Cause This condition may be caused by a damaged forward sprag assembly (642). Correction When inspecting the sprag, it is important to test the sprag for proper operation by holding the outer race (644) with one hand while rotating the input sun gear (640) with the other hand. The sun gear should rotate only in the counterclockwise direction with the input sun gear facing upward. If the sprag rotates in both directions or will not rotate in either direction, the sprag elements should be inspected by removing one of the sprag assembly retaining rings (643). Refer to SI Unit Repair section for forward clutch sprag disassembly procedures. If the sprag is found to be damaged, make repairs to the transmission as necessary. A new forward roller clutch sprag assembly is now available from GMSPO. Page 5480 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 2894 Diagnostic Circuit Circuit Description The diagnostic circuit check is an organized approach to identifying a problem created by an electronic engine control system malfunction. It must be the starting point for any driveability complaint diagnosis, because it directs the service technician to the next logical step in diagnosing the complaint. Understanding the chart and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of good parts. Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. This step is a check for the proper operation of the "Service Engine Soon" light. The "SES" light should be "ON" steady. 2. No "SES" light at this point indicates that there is a problem with the "SES" light circuit or the control module control of that circuit. 3. This test checks the ability of the control module to control the "SES" light. With the diagnostic terminal grounded, the "SES" light should flash a Code 12 three times, followed by any trouble code stored in memory. A PROM error may result in the inability to flash Code 12. 4. Most of the diagnostic charts use a Tech 1 to aid diagnosis, therefore, serial data must be available. If a PROM error is present, the control module may have been able to flash Code 12 or 51, but not transmit serial data. 5. Although the control module is powered up, a "Cranks But Will Not Run" symptom could exist because of an control module or system problem. 6. This step will isolate if the customer complaint is a "SES" light or a driveability problem with no "SES" light. See: Testing and Inspection/Diagnostic Trouble Code Descriptions for a list of valid codes. An invalid code may be the result of a faulty "Scan" tool, PROM or control module. 7. Comparison of actual control system data with the typical valves is a quick check to determine if any parameter is not within limits. Keep in mind that a base engine problem (i.e., advanced cam timing) may substantially alter sensor values. 8. If the actual data is not within the typical values established, refer to individual component tests. Page 7721 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7848 Fuel Pump And Sender Assembly (Typical) Page 6643 Speaker: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 4953 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Specifications Water Pump: Specifications Water Outlet Bolts 21 ft.lb Water Pump Bolts 30 ft.lb Service and Repair Seals and Gaskets: Service and Repair REMOVE OR DISCONNECT - Tools Required: - J 8614-01 Companion Flange Holder 1. Bolts and retainers. Important: It is essential that the positions of all driveling components relative to the propeller shaft and axles be observed and accurately reference marked prior to disassembly. These components include the propeller shafts, drive axles, pinion flanges, output shafts, etc. All components must be reassembled in the exact relationship to each other as they were when removed. Specifications and torque values, as well as any measurements made prior to disassembly, must be followed. - Accurately mark the installed position of the propeller shaft and pinion flange so they can be reassembled in the same position. 2. Propeller shaft from the pinion flange. A. Use a piece of tape to hold the bearing caps. B. Secure the propeller shaft up and out of the way so as not to put unnecessary stress on the universal joints. C. Make an accurate alignment mark on the pinion stem, pinion flange, and pinion flange nut. Also record the number of exposed threads on the pinion stem for reference. Page 89 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 4627 4. Install J 39177 on the combination valve (figure 2). 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described in SECTION 5. 7. Close the internal bleed valves. TIGHTEN * Internal bleed valves (A) to 7 N-m (60 lbs.In.). 8. Remove the three J 39177 Combination Valve Pressure Bleeding Tools. 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the Ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure as many times as needed to remove the remaining air in the hydraulic system. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 2168 Coolant: Technical Service Bulletins Cooling System - Reconstituted Anti-Freeze Information Number: 90-49-6B Section: 6B Date: August 1989 Corporate Bulletin No.: 930107 Subject: RECONSTITUTED ANTI-FREEZE Model and Year: ALL MODELS, ALL MODEL YEARS TO: ALL CHEVROLET DEALERS This bulletin provides information on "reconstituted anti-freeze". It has been brought to our attention that a number of manufacturers claim to have the capability of reconstituting engine coolant on site. At this time, General Motors does not endorse this practice or any equipment. Anti-freeze recycling is a very complex issue. In use as an engine coolant, ethylene glycol becomes oxidized producing a very degraded and deteriorated substance. Contamination by other automotive fluids during draining, handling and storage is also a major detriment to the reclaiming process. There is no additive we are aware of that can be merely put into used coolant that will restore it to an acceptable state. Typically, a multi-million dollar facility, utilizing sophisticated technology with distillation capabilities along with appropriate quality control would be required to adequately process used coolant to bring it to GM specifications. Disposal of all chemical products should be done in accordance with all applicable federal, state and local laws and regulations. Review engine coolant substitutes Dealer Service Bulletin No. 89-57-6B, dated January 1989. Engine - Tick Or Rattle/Detonation Or Rattle Noise Intermediate Shaft: Customer Interest Engine - Tick Or Rattle/Detonation Or Rattle Noise FILE IN SECTION: 6 - Engine BULLETIN NO.: 23-61-11 DATE: June, 1995 SUBJECT: CPI Engine Noise (Install New Gears/New MEM-CALs) MODELS: 1992 Chevrolet and GMC Truck S/T, M/L Models 1992 Oldsmobile Bravada with 4.3L CPI Engine (VIN W - RPO L35) This bulletin is being revised to update engine scrapping information. Previous divisional publication numbers were: Chevrolet 92-244B-6 GM of Canada 93-6A-121 GMC Truck 92-6A-153A Oldsmobile 92-T-168 CONDITION Some 1992 model year 4.3L CPI engines may exhibit one or both of the following noises: I. A tick or rattle noise at idle or low engine speeds up to 1300 RPM. The noise may occur hot or cold in Park/Neutral or in gear. II. A detonation or rattling type noise under acceleration at engine speeds between 2000 - 2500 RPM. It is usually most noticeable at the shift points under moderate acceleration with the transmission torque converter unlocked. Premium grade fuel does not affect the noise. III. If an engine has both noises (conditions "I" and "II"), follow condition "II" for cause and correction instructions and information. CAUSE I. The most probable cause for the idle tick or rattle (condition I) is due to zero or near zero lash between the balance shaft drive gears. Some gears may feel as if the lash is acceptable but there is most likely an area on one of the teeth which is not meshing properly with the other gear. II. The source of the detonation or rattling type noise under acceleration between 2000 - 2500 RPM (condition II) is the rear balance shaft needle bearing. With some engines, the rear needle bearing is excited by a combination of factors (i.e., engine case, combustion events, balance shaft gear lash, valve train torque reversals, cam chain play, needle bearing clearance, etc.). Important: If there is any question about the proper diagnosis of the noise, call Technical Assistance. The unnecessary customer inconvenience and/or replacement of parts must be avoided. It is important to note that neither noise is a reliability or dependability concern. The noises are a customer pleasability issue only. The life of the engine will not be shortened due to the above causes. CORRECTION I. The following steps should be followed to correct an idle tick noise (condition I). 1. Remove the accessory drive belt. 2. Start the engine and note the noise. If it is still present proceed to step "3"; if not, proceed with diagnosis of accessory drive per the service manual procedures. Important: Do not allow the engine to operate for an extended period of time with the accessory drive belt off. Remember the water pump and fan are not functioning. Overheat will eventually occur. 3. Order GMSPO B/S Gear Kit # 12513234 and W/P; front cover gaskets. Use the following steps to replace the balance shaft gears. Page 7481 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 4230 Providing responsible services at the proper intervals will greatly aid your dealership with repeat business, and additional services when required. Most customers appreciate and gain trust in the dealership that informs and offers them just what they need for continued trouble-free operation. Examine your service department's practices and verify that all Service Consultants and Technicians focus on customer satisfaction, vehicle inspections, and other products at time of service. Use this opportunity to upgrade the services you provide to your customers. Here are a few suggestions: - Take the time required to align your dealership service practices with the new GM Simplified Maintenance Schedule. Use the new vehicle Owner's Manual Maintenance I and II schedules to create a "mirror image" in your advertising and dealer service pricing that is easily understandable to your customer. Taking advantage of this new service strategy may greatly increase your dealership service sales and customer retention while decreasing the frequency of visits and inconvenience to your customer. - Review your program to ensure that all vehicles coming in are evaluated for safety and wear items. Examine all vehicles for tire condition, signs of misalignment, brake wear, exterior lamp functionality, exhaust condition, A/C cooling performance, SRS or Air Bag MIL, along with Service Engine Soon or Check Engine indicators. If the Service Engine Soon or Check Engine MIL is illuminated, it is vital that you inform the customer of the concerns with ignoring the indicator and what the required repair would cost. In addition to the possibility of increased emissions and driveability concerns, many customers are unaware that lower gas mileage may also result, with additional cost to the customer. - Be complete in your service recommendations. Some sales opportunities are not being fully pursued nationally. Focus on overlooked but required maintenance that has real benefits to the customer. Many vehicles are equipped with cabin air filters. If these filters are used beyond replacement time, they may impede airflow decreasing A/C and heating performance. Make sure these filters are part of your recommended service. Note that some of our vehicles may not have been factory equipped but will accept the filters as an accessory. - Express the value in maintaining the finish quality of the customer's vehicle at the Maintenance I and II visits. More fully utilize the vehicle prep personnel you already have in place. In today's world, many people simply ignore the finish of their vehicle, at best infrequently using an automatic car wash for exterior cleaning. Offer vehicle detailing services in stages from just a wash and wax to a complete interior cleaning. When paired with the Simplified Maintenance visit, this will increase customer satisfaction. On return, the customer gets a visibly improved vehicle that will be a source of pride of ownership along with a vehicle that is now fully maintained. Also, reinforce the improved resale value of a completely maintained vehicle. - For customers who clean and maintain the appearance of their vehicles themselves encourage the use of GM Vehicle Care products. Many customers may have never used GM Car Wash/Wax Concentrate, GM Cleaner Wax or a longtime product, GM Glass Cleaner, which is a favorite of many customers who try it just once. If your dealership give samples of these products with new car purchases, customers may already be sold on the product but not willing to make a special trip to the dealership. Capitalize on sales at this time. Stock shelves right at the Service counter with these products and consider instituting compensation programs for Service Consultants who suggest these products. Many consumers faced with an intimidating wall full of car care products sold at local auto parts stores may find it comforting to purchase a fully tested product sold by GM that they know will not harm the finish of their vehicle. We suggest these competitively priced basic vehicle care products to emphasize: In USA: - #12378401 GM Vehicle Care Wash/Wax Concentrate 16 fl. oz. (0.473L) - #89021822 GM Vehicle Care Glass Cleaner Aerosol 18 oz. (510 g) - #12377966 GM Vehicle Care Cleaner Wax 16 fl. oz. (0.473L) - #1052929 GM Vehicle Care Chrome and Wire Wheel Cleaner 16 fl. oz. (0.473L) - #88861431 GM Vehicle Care Odor Eliminator 24 fl. oz. (0.710L) In Canada: - #10953203 GM Vehicle Care Wash & Wax Concentrate 473 mL - #992727 GM Glass Cleaner Aerosol 500 g - #10952905 GM Vehicle Care Liquid Cleaner/Wax 473 mL - #10953013 GM Vehicle Care Chrome Cleaner and Polish 454 mL - #10953202 GM Vehicle Care Wheel Brite 473 mL - #88901678 GM Vehicle Care Odor Eliminator 473 mL - Display signboards with the installed price for popular GM Accessories such as running boards and Tonneau Covers. Customers may not think to ask about these desirable items at the time of a service visit. - Finally, take advantage of the GM Goodwrench initiatives (Tire Program, Goodwrench Credit Card, etc. / Dealer Marketing Association (DMA) Promotions in Canada) to provide the customer with more reasons to identify your dealership as the best place to go for parts and service. Remember to utilize ALL of the service aspects you possess in your dealership to satisfy and provide value to your customer. Many businesses exist profitably as an oil change location, a vehicle repair facility, or a detailing shop alone. You already have the capabilities of all three and provide these services with the inherent trust of your customer, under the GM Mark of Excellence. Disclaimer Page 5202 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 2431 ECM Connector C2 Radio - Buzzing Noise in AM Band With Engine Running Radio/Stereo Noise Filter: All Technical Service Bulletins Radio - Buzzing Noise in AM Band With Engine Running Group Ref.: Accessories Bulletin No.: 449601 Date: April, 1994 SUBJECT: BUZZING NOISE IN AM BAND OF RADIO (INSTALL FILTER ON PCM/TCM) MODELS: 1992-94 CHEVROLET AND GMC TRUCK C/K, S/T TRUCKS AND M/L, G VANS 1992-94 OLDSMOBILE BRAVADA WITH 4L60-E AND 4L80-E TRANSMISSIONS CONDITION: Some owners may comment of a buzzing noise in the low end of the AM radio band with the engine running. CAUSE: The switching of the force motor in the electronic transmission emits an RFI signal through the PCM/TCM. The AM band of the radio is receiving this interference through the antenna. CORRECTION; To determine if this is the cause of the owner's comments. first duplicate the condition and then disconnect the electrical connector at the transmission (this will disable the force motor). If the condition improves. install an in-line filter (P/N 1224205) to the ignition lead (ckt 439) of the PCM/TCM. Some applications may have two (439 ckt), in which case, a filter will be required for each lead. NOTE: Disconnecting the electrical connector at the transmission will set the transmission diagnostic codes. It will be necessary to remove these codes after the corrective action has been performed. IMPORTANT: Discard the instructions in the filter package. This filter Is an in-line filter with a single lead on one end and two leads on the other end (one lead being black (ground). Install this filter as close to the PCM/TCM connector as possible. It Is important to Install the filter with the single lead end going toward the PCM/TCM and then take the black (ground) lead back and attach it to the case of the PCM/TCM. If this filter is installed incorrectly, the condition will become worse. SERVICE PARTS INFORMATION: Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Locations Electronic Spark Control (ESC) Module Page 85 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 6109 Blower Motor Relay: Service and Repair Evaporator And Blower Assembly Component View REMOVE OR DISCONNECT 1. Electrical connectors, as necessary. 2. Screws (34). 3. Relay (42). INSTALL OR CONNECT 1. Relay (42). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 2. Screws (34). 3. Electrical connectors, as necessary. - Check circuit operation. Page 7451 Clutch Switch: Locations Cruise Control Clutch Switch Brake Pedal Switches. On the Clutch Pedal Support bracket. Page 7632 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 3592 Knock Sensor: Testing and Inspection Electronic Spark Control (ESC) Circuit Check Page 4391 Universal Joint: Service and Repair Cross & Roller Type With Joint Replacement Fig. 1 Production Type Universal Joints Which Use Nylon Injection Rings In Place Of Snap Rings Fig. 2 Service Type Universal Joints (Internal Snap Ring Type) Fig. 3 Cross & Roller Type Universal Joints Page 5365 Fuse: Locations Inline Fuse, Underhood Lamp Between Underhood Lamp & Junction Block Locations Power Steering Pressure Switch Wiring Page 7259 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 2526 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Left Side Knock Sensor Engine Wiring, LH Side Page 3473 Throttle Position Sensor: Description and Operation TP Sensor Throttle Position Sensor (TPS) PURPOSE The Throttle Position Sensor (TPS) is a non-adjustable potentiometer that senses throttle angle and relays the information to the control module. This input to the control module is used to control the fuel system and most of the control module outputs. CONSTRUCTION The TPS has internally three circuits. One to ground, the other from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage . As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). OPERATION As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation movement to the TP sensor. A potentiometer (variable resistor) within the Throttle Position (TP) sensor assembly changes its resistance in proportion to throttle movement. If the TP sensor senses a Wide Open Throttle (WOT) a voltage signal indicating this condition is sent to the control module. The control module then increases the injector base pulse width, permitting increased fuel flow. LOCATION The non-adjustable Throttle Position (TP) sensor, is mounted on the side of the throttle body opposite the throttle lever assembly. Coolant Temperature Switch Engine Wiring, LH Side Page 7364 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 2801 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 4720 Wheel Cylinder: Fundamentals and Basics REMOVAL - Wheel cylinder retaining bolts, brake line fittings, and bleeder screws are often heavily corroded. Prior to starting the job you should spray these with a penetrating oil. - A line (flare nut) wrench should be used when loosening the brake line fittings. These fittings round off easily. OVERHAUL - Light amounts of corrosion within the cylinder bore and on the piston may be removed with crocus cloth. - Pitting and heavy corrosion should be removed with a hone. When honing the hone should be inserted and withdrawn quickly to achieve a 45 degree crosshatch. - Closely inspect the areas of the cylinder where the pistons seals contact. It is very important these areas are absolutely free of deposits, corrosion, or pitting. - Remove the bleeder screw and verify that the passage is clear. - Leave the bleeder open when installing pistons and cups into the cylinder bore. If the bleeder is closed a large amount of air will be forced into the brake lines. - Use brake assembly lubricant to coat the cylinder bore, pistons, and cups. Clean brake fluid is an acceptable lubricant when assemblying the wheel-cylinder but brake assembly lubricant is much slicker and minimizes the chance that the cups will be damaged. WARNING: Do not use a petroleum based grease or oil to lubricate the wheel-cylinder components. This will cause the seals and cups to swell and deteriorate. - When reassemblying the wheel-cylinder it is helpful to follow this sequence: 1. Rear cup (verify the cup is inserted properly, flat side towards the piston, concave side towards the center) 2. Rear piston 3. Rear dust cap (this prevents the rear cup and piston from popping back out when the spring and front components are installed). 4. Spring 5. Front cup 6. Front piston 7. Front dust cap INSTALLATION Attach the brake fluid line fitting loosely to the wheel-cylinder prior to inserting and tightening the retaining bolts. The brake fluid line fitting is much easier to attach and start turning with the wheel-cylinder loose. WARNING: Don't forget to tighten the brake line fitting after the retaining bolts are tightened. - Leave the wheel-cylinder bleeder screw open and place a drip pan under the rear brake assembly. Refill the master-cylinder with new brake fluid and let the fluid gravity bleed through the open bleeder screw. When brake fluid begins to drip from the bleeder, close the bleeder screw. NOTE: The brake system will still need to be flushed and bled, but this makes starting the process much easier. Page 4118 Valve Body: Locations 4L60-E Automatic Transmission Pressure Switch Manifold (PSM) Assembly The Pressure Switch Manifold (PSM) Assembly is located on valve body assembly, inside the transmission, behind the transmission service pan. Page 6674 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 4559 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 180 Engine Control Module: Description and Operation Powertrain Control Module (PCM) PURPOSE The Control Module is the control center of the fuel injection system. It constantly looks at the information from various sensors (inputs) and controls the systems (outputs) that affect vehicle performance. The control module also performs the diagnostic control moduletion of the system. It can recognize operational problems, alert the driver through the Malfunction Indicator Lamp (MIL) "Service Engine Soon" light on the instrument panel and store a Diagnostic Trouble Code(s) (DTC) in the control module memory. The DTC identifies the problem areas to aid the technician in performing repairs. OPERATION The control module is an electronic computer designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The control module can control these devices through the use of Quad Driver Modules (QDM). When the control module is commanding a device or a component "ON," the voltage potential of the output is "LOW" or near zero volts. When the control module is commanding a device or component "OFF," the voltage potential of the circuit will be "HIGH," or near 12 volts. The primary function of the QDM is to supply the ground for the component being controlled. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The control module has two parts for service: - Controller which is the control module without the PROM (MEM-CAL). - PROM (Programmable Read Only Memory) which is a separate memory calibrator unit Learning Ability The control module has a "learning" ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected, to clear diagnostic trouble codes or for other repairs. the "learning" process resets and begins again. A change may be noted in the vehicle's performance. To "teach" the vehicle, ensure the engine is at operating temperature. The vehicle should be driven at part throttle, with moderate acceleration and idle conditions until normal performance returns. NOTE The control module must be maintained at a temperature below 85°C (185°F) at all times. This is most essential if the vehicle is put through a baking process. The control module will become inoperative if it's temperature exceeds 85°C (185°F). It is recommended that temporary insulation be placed around the control module during the time the vehicle is in a paint oven or other high temperature processes. Page 2525 Electronic Spark Control (ESC) Circuit Circuit Description: The Code 43 circuit consists of two knock sensors with one wire that goes directly to the ECM. There are two Code 43 checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 4.4 volts. If voltage is either too high or too low for 2 or more seconds, Code 43 will set. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3800 rpm, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, Code 43 will set. Diagnostic Aids: The ECM applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the ECM, is able to read this signal as knock and incrementally retard spark. If the ESC system checks OK, but detonation is the complaint, See: Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Page 4260 Differential Axle Housing: Service and Repair Chevrolet Full Floating Axle 1.. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Page 4992 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 5462 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 A/T - Revised 3-4 Clutch Clutch: All Technical Service Bulletins A/T - Revised 3-4 Clutch Number: 93-143-7A Section: 7A Date: MARCH 1993 Corporate Bulletin No.: 377117 ASE No.: A2 Subject: TRANSMISSION UNIT REPAIR UPDATE 3-4 CLUTCH Model and Year: 1987-93 CAPRICE, CAMARO AND CORVETTE 1987-93 G AND M VAN 1987-93 C/K, R/V AND S/T TRUCKS 1990-93 L VAN WITH 4L60 AND 4L60-E AUTOMATIC TRANSMISSION SERVICE UPDATE BULLETIN COVERS: New Product Information for 1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. This information has been updated since publication of the 1993 Service Manual and should be noted accordingly. Be certain to familiarize yourself with these updates to properly repair the 1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. DATE OF PRODUCTION CHANGE: On January 05, 1993 (Julian Date 005) HYDRA-MATIC 4L60 and 4L60-E transmissions were built with an improved design 3-4 clutch. The improved design consisted of combining the 3rd and 4th clutch ring retainer plate (III. 652), the 3rd and 4th clutch apply (stepped) plate (III. 653) and the 3rd and 4th clutch (steel) plate (III. 654C) into one 3rd and 4th clutch apply plate (III. 653) Figure 1. The 3rd and 4th clutch steel plates are also thicker and the backing plate selection has changed as noted in Figure 2. Wheels/Tires - Use of Nitrogen Gas in Tires Tires: All Technical Service Bulletins Wheels/Tires - Use of Nitrogen Gas in Tires INFORMATION Bulletin No.: 05-03-10-020C Date: April 27, 2010 Subject: Use of Nitrogen Gas in Tires Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-03-10-020B (Section 03 - Suspension). GM's Position on the Use of Nitrogen Gas in Tires General Motors does not oppose the use of purified nitrogen as an inflation gas for tires. We expect the theoretical benefits to be reduced in practical use due to the lack of an existing infrastructure to continuously facilitate inflating tires with nearly pure nitrogen. Even occasional inflation with compressed atmospheric air will negate many of the theoretical benefits. Given those theoretical benefits, practical limitations, and the robust design of GM original equipment TPC tires, the realized benefits to our customer of inflating their tires with purified nitrogen are expected to be minimal. The Promise of Nitrogen: Under Controlled Conditions Recently, nitrogen gas (for use in inflating tires) has become available to the general consumer through some retailers. The use of nitrogen gas to inflate tires is a technology used in automobile racing. The following benefits under controlled conditions are attributed to nitrogen gas and its unique properties: - A reduction in the expected loss of Tire Pressure over time. - A reduction in the variance of Tire Pressures with temperature changes due to reduction of water vapor concentration. - A reduction of long term rubber degradation due to a decrease in oxygen concentrations. Important These are obtainable performance improvements when relatively pure nitrogen gas is used to inflate tires under controlled conditions. The Promise of Nitrogen: Real World Use Nitrogen inflation can provide some benefit by reducing gas migration (pressure loss) at the molecular level through the tire structure. NHTSA (National Highway Traffic Safety Administration) has stated that the inflation pressure loss of tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "seeping" through the tire casing. The actual obtainable benefits of nitrogen vary, based on the physical construction and the materials used in the manufacturing of the tire being inflated. Another potential benefit of nitrogen is the reduced oxidation of tire components. Research has demonstrated that oxygen consumed in the oxidation process of the tire primarily comes from the inflation media. Therefore, it is reasonable to assume that oxidation of tire components can be reduced if the tire is inflated with pure nitrogen. However, only very small amounts of oxygen are required to begin the normal oxidation process. Even slight contamination of the tire inflation gas with compressed atmospheric air during normal inflation pressure maintenance, may negate the benefits of using nitrogen. GM Tire Quality, Technology and Focus of Importance Since 1972, General Motors has designed tires under the TPC (Tire Performance Criteria) specification system, which includes specific requirements that ensure robust tire performance under normal usage. General Motors works with tire suppliers to design and manufacture original equipment tires for GM vehicles. The GM TPC addresses required performance with respect to both inflation pressure retention, and endurance properties for original equipment tires. The inflation pressure retention requirements address availability of oxygen and oxidation concerns, while endurance requirements ensure the mechanical structure of the tire has sufficient strength. This combination has provided our customers with tires that maintain their structural integrity throughout their useful treadlife under normal operating conditions. Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Maintaining the correct inflation pressure allows the tire to perform as intended by the vehicle manufacturer in many areas, including comfort, fuel economy, stopping distance, cornering, traction, treadwear, and noise. Since the load carrying capability of a tire is related to inflation pressure, proper inflation pressure maintenance is necessary for the tire to support the load imposed by the vehicle without excessive structural Page 641 Manifold Pressure/Vacuum Sensor: Testing and Inspection Manifold Absolute Pressure Output Check Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures the changes in the intake manifold pressure which result from engine load (intake manifold vacuum) and rpm changes; and converts these into a voltage output. The control module sends a 5 volt reference voltage to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the control module knows the manifold pressure. At lower pressure output voltage will be about 1 to 2 volts. While at higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts.The MAP sensor is also used, under certain conditions, to measure barometric pressure, Page 7737 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Locations CMFI Assembly Parts Identification Page 4096 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 6070 Air Door Cable: Service and Repair Control Assembly Control Cable REMOVE OR DISCONNECT 1. Control assembly (63). 2. Cables (60 and 65) at the control assembly (63) and heater assembly. 3. Cables (60 and 65). INSTALL OR CONNECT 1. Cables (60 and 65). Page 3436 Idle Speed/Throttle Actuator - Electronic: Service and Repair NOTE - If IAC valve has been in service: Do NOT push or pull on the IAC valve pintle. The force required to move the pintle may damage the threads on the worm drive. - Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. - On this TBI unit, the IAC valve is flange mounted, with a dual taper, 10 mm diameter pintle. If replacement is necessary, only an IAC valve identified with the correct part number (having the appropriate pintle shape and diameter) should be used. Flange Mounted IAC Valve REMOVE/DISCONNECT - Electrical connector from IAC valve. - Screw assemblies and IAC valve. - IAC valve o-ring and discard. CLEAN - Both original and replacement IAC valves have a special factory applied thread-locking compound applied to the screw threads. If the valve removed from throttle body is being reinstalled, DO NOT remove thread-locking that may remain on the threads. - Clean IAC valve seating surfaces on throttle body to assure proper seal of new O-ring and contact of IAC valve flange. Adjusting IAC Valve Pintle NOTES - If IAC valve was removed during service, its operation may be tested electrically with the IAC/ISC Motor Tester (J-37027 or BT-8256K) or equivalent. Before installing IAC valve, measure the distance between the tip of valve pintle and mounting surface. If the dimension is greater than 28.0 mm (1.10 inches), valve pintle must be retracted to prevent damage to valve. This may be done electrically using an IAC/ISC Motor Tester or manually by exerting firm pressure, as shown in the illustration, with a slight side to side movement on valve pintle to retract it. - No physical adjustment of IAC valve assembly is required after installation. The IAC valve pintle is reset by turning the ignition "ON" for ten seconds and then "OFF". The control module then resets the pintle to the correct position. Proper idle regulation should result. INSTALL/CONNECT - Lubricate new o-ring with transmission fluid and install on IAC valve. - IAC valve to throttle body. - IAC valve attaching screw assemblies that have been coated with appropriate thread locking compound. Tighten screw assemblies to 3.0 Nm (27.0 lb-in). - Electrical connector to IAC valve. - Reset IAC valve pintle position: a. Disconnect negative battery for at least ten seconds to clear control module memory. (Ensure ignition is "OFF".) b. Reconnect negative battery cable. c. "START" engine and allow engine to reach operating temperature. Check for proper idle operation. Locations Engine Wiring, LH Side Page 7100 Time Allowance: See Chants NOTE: The time allowances provided on the chart include the hardware removal and installation (as indicated by the list guidelines), the masking and unmasking of the vehicle, stripping of the surface (as indicated by the guidelines), the refinish (and colorcoat when required), mix time for primer/ paint (and clearcoat when required), finesse/polish where required, washing and preparing the vehicle for delivery. OPERATION DESCRIPTION: PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER, REFINISH ENTIRE BODY ABOVE BODY SIDE MOLDINGS. PAINT TERM DEFINITIONS Following are definitions of paint repair terms used in this bulletin: Basecoat: A color topcoat that requires a clear topcoat over it. Break line: A natural dividing line on Page 6076 Air Duct: Service and Repair Plenum Side Vent REMOVE OR DISCONNECT 1. Front door sill plate. 2. Plenum side vent cover. 3. Bolts (102). 4. Vent (103). INSTALL OR CONNECT 1. Vent (103). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 2. Bolts (102). - Tighten Bolts (102) to 2 Nm (18 in. lb.). 3. Plenum side vent cover. 4. Front door sill plate. Tires - Slipping on Rim Tires: All Technical Service Bulletins Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Page 799 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Adjustments Idle Speed Control Motor: Adjustments Base Idle Speed is not adjustable on this engine and is controlled by the control module. Refer to FUEL SUPPLY AND AIR INDUCTION/ADJUSTMENT PROCEDURES for adjusting Controlled Idle Speed. Page 938 Spark Plug Wire: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Page 4979 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 6634 Speaker: Locations Rear Rear Speaker Wiring (extended Cab) Locations ABS Main Relay: Locations EHCU Module Mounting The relay is located inside the Electro-Hydraulic Control Unit EHCU, also know as the Brake Pressure Modulator Valve (BPMV). Page 5715 Fig. 11 Lower Control Arm Rear Bushing Installation. 4 X 2 Models 1. Remove coil spring as outlined in COIL SPRING. 2. Remove lower control arm pivot bolts, refer to COIL SPRING. 3. Drive bushing flare down flush with rubber of front bushing, then remove front and rear bushings from control arm, Figs. 7 and 8. 4. Install front bushing, Fig. 9, then flare the bushing, Fig. 10. 5. Install rear bushings, Fig. 11, then the lower control arm as described previously. 4X4 Fig. 12 Lower Control Arm Bushing Replacement. 4 X 4 Models 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Unload torsion bar. 4. Remove stabilizer shaft. 5. Remove shock absorber as outlined in SHOCK ABSORBER. 6. Remove control arm pivot bolts then the lower control arm. 7. Remove lower control arm front and rear bushings, refer to Fig. 12. 8. Reverse procedure to install. Page 6895 Symbol Identification Page 7814 Page 6186 Removing Pulley Rotor And Bearing Assembly 3. Install pulley rotor and bearing puller guide J 33023-A to the front head and install J 33020 pulley rotor and bearing puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots to engage the puller tangs with the segments between the slots in the rotor. 4. Hold the J 33020 puller in place arid tighten the puller screw against the puller guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal the rotor hub must be properly supported. Pulley Rotor Bearing Removal Remove the forcing screw from J 33020 puller and, with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks as shown in the illustration. 6. Drive the bearing out of the rotor hub with rotor bearing remover J 9398-A and J 29886 universal handle. Page 5796 degradation. Important Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Disclaimer Page 387 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7731 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 5743 5. Reposition the vertical tangs (85) in the upper spring pocket bracket (86) by bending them inward with pillars in a horizontal position (Figure 8). Remove any sharp edges or burrs off of the upper coil spring pocket by using a die grinder or metal file. CAUTION: The upper spring pocket has sharp edges and burrs on it. Care must be taken to avoid personal injuries. Install or Connect (Figures 1, 2, 3, 4, 5, 6, 7, and 8): Tool Required: J23028-01 Coil Spring Remover and Installer. 1. Install Service Kit (P/N 15989719) one insulator with insert on the top of coil spring and remaining insulator on the bottom of the coil spring (If the opposite side of the vehicle requires the same repair procedures, then another Service Kit (P/N 15989719) will be required.) 2. Install the coil spring (37) with insulators (73) on the lower control arm (40) (Figure 1). a. Using J23028-O1 to support the control arm (Figure 5). b. Position the coil spring (A) (Figure 6). - Coil spring installed with the tape at the lowest position and a gripper notch at the top. - Inspect drain holes, one of which must be covered by the end of the spring and one must be open. 3. Install the lower control arm (40) to the frame. 4. Install the pivot bolts (72 and 77) and nuts (71 and 78) (Figure 1). IMPORTANT: In order to maintain adequate steering linkage clearance, refer to mandatory bolt direction of installation in Figure 6. - Mandatory Bolt and Nut Positions - Front Bolt First Tighten: a. Tighten front nut (76) to 90 N-m (67 lbs.ft.) (Figure 1). b. Tighten rear nut (71) to 90 N-m (67 lbs.ft.) (Figure 1). 5. Install stabilizer shaft (53) to lower control arm (40). a. Install the retainer (61), and grommet (60) (Figure 3) to the link bolt (62) (Figure 3). Page 7729 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Locations Steering Column Multi-function Switch Page 5040 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 2339 Radiator: Technical Service Bulletins Cooling - Radiator Repair/Replacement Guidelines File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-02-017 Date: October, 1999 INFORMATION Subject: Radiator Repair/Replacement Guidelines Models: 2000 and Prior Passenger Cars and Trucks If repair of an aluminum/plastic radiator is required, it is recommended that the following guidelines be followed: For Vehicles Under Warranty For aluminum/plastic radiators that have damage to the face of the core including bent fins, punctures, cuts, leaking tubes or header tubes, the aluminum radiator core section should be replaced with a new one. In these cases, if both of the plastic tanks are not damaged, they can be reused with the new core. If one or both of the plastic tanks are damaged along with the core, it is recommended that a complete new radiator assembly be installed. Warranty repairs for leaks at the tank to header (gasket leaks), broken/cracked plastic tanks, cross threaded or leaking oil coolers should be repaired without replacing the complete radiator. This type of repair should be handled by the radiator repair facility in your area. Many of these radiator repair facilities are members of the National Automotive Radiator Service Association (NARSA) who follow industry and General Motors guidelines when repairing radiators. These facilities have the special tools, tanks and pressurizing equipment needed to properly test the repaired radiator prior to returning it to the dealership. Many of these facilities receive the repair components directly from General Motors. The sublet expense for a new radiator or the repair of the radiator under warranty should be handled following normal procedures. For Vehicles No Longer Under Warranty The GM released epoxy repair kit referenced in previous publications is no longer available. Repairs to the radiator, rather than replacement, is strictly at the owner's discretion. Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Page 2436 Engine Control Module: Component Tests and General Diagnostics ECM QDR Check Procedure ECM QDR Check Procedure Page 8466 Door Switch: Locations Door Jamb Switch, LH Front In LH A-Pillar Page 5321 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 7165 Symbol Identification Page 7682 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Door Locks - Binding or Sticking or Key Hard to Insert Door Lock Cylinder: All Technical Service Bulletins Door Locks - Binding or Sticking or Key Hard to Insert Number: 93-133-10 Section: 10 Date: MARCH 1993 Corporate Bulletin No.: 1341070R ASE No.: B1 Subject: DOOR LOCK CYLINDERS (RECOMMENDED LUBRICATION) Model and Year: ALL 1993 AND PREVIOUS MODEL CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN 92-41-10, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS A NOTE. PLEASE DISCARD ALL COPIES OF 92-41-10. Customer comments of binding/sticking door lock cylinders, or keys that are hard to insert or extract may be corrected in many cases by applying the proper lubrication. The recommended materials for lubricating these components are (in order of preference): - GM # 12345120 Multi purpose lubricant (9 oz. spray) or # 12345121 (12 oz.). - 5 W 30 Motor Oil - GM # 1052276 or 1052277 spray type Silicone (4.5 oz. or 12 oz. cans). Penetrating oil type lubricants (such as GM # 1052949 or 1052950, WD-40 lubricants) ARE NOT RECOMMENDED because they wash out the original lubrication and eventually evaporate, leaving little or no lubricating material. However, if these type materials are used to "unfreeze" or loosen lock cylinder components, refer to steps 2 through 4 listed below for the proper methods of lubricating. NOTE: DO NOT REPLACE THE DOOR LOCK CYLINDERS UNTIL AFTER THE LUBRICATING MATERIALS HAVE BEEN USED AND THE CYLINDER REMAINS FROZEN/BOUND. If door lock cylinders require replacement for any reason, apply a coating of GM # 12345120 Multi purpose Lubricant to the inside of the lock case and the cylinder keyway prior to assembling and installing the cylinder. Parts are currently available from GMSPO. Frozen cylinders due to cold weather may be repaired using the following procedure: 1. Apply heat to the cylinder area with a heat gun while being careful not to damage the painted surfaces. 2. Hold the shutter door open with a paper clip (or similar item) and force air into the cylinder using compressed air and a blow gun attachment. 3. While holding the shutter door open, inject a small amount of lubricant (see above recommendations) into the cylinder. 4. Work the key into the cylinder several times and wipe any excess lubrication residue from the key. Use applicable Labor Time Number and Time allowance. Page 8559 Vanity Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. A/T - 1-2 Accumulator Piston/Outer Spring Replacement Accumulator: All Technical Service Bulletins A/T - 1-2 Accumulator Piston/Outer Spring Replacement File In Section: 7 - Transmission Bulletin No.: 87-71-74 Date: November, 1998 INFORMATION Subject: 1-2 Accumulator Piston and Outer Spring Replacement Models: 1982-96 Buick Roadmaster 1982-96 Cadillac Brougham, Fleetwood, DeVille 1982-86 Chevrolet Caprice 1982-99 Chevrolet Camaro, Corvette 1982-99 Pontiac Firebird with HYDRA-MATIC 4L60, 4L60-E Transmission (RPOs MD8, M30) 1982-99 Chevrolet and GMC C/K, M/L, S/T, G Models 1991-99 Oldsmobile Bravada with HYDRA-MATIC 4L60, 4L60-E Transmission (RPOs MD8, M30) Transmissions built from 1982 through 1999 were built with one of two styles of 1-2 accumulator pistons and outer springs. Important: The 1-2 accumulator pistons and outer springs are not interchangeable. For replacement of the 1-2 accumulator piston and outer spring, remove the 1-2 accumulator assembly and inspect the interior for the presence of either an aluminum or composite (plastic) 1-2 accumulator piston. Design 1 1-2 accumulator assemblies with an aluminum piston and a round wire outer spring, use service package P/N 24204495 (1982-1993) or P/N 24204496 Diagram Information and Instructions Brake Fluid Pump: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Diagram Information and Instructions Cruise Controller: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 5280 Convenience Center (with Digital Cluster) Page 5459 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 6378 4L60 & 4L60-E Transmission Transmission Speed Sensor: Specifications 4L60 & 4L60-E Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Description and Operation Diode Trio: Description and Operation Alternators are composed of the same functional parts as the conventional D.C. generator but they operate differently. The field is called a rotor and is the turning portion of the unit. The generating part, called a stator, is the stationary member, comparable to the armature in a D.C. generator. The regulator, similar to those used in a D.C. system, regulates the output of the alternator-rectifier system. The power source of the system is the alternator. Current is transmitted from the field terminal of the regulator through a slip ring to the field coil and back to ground through another slip ring. The strength of the field regulates the output of the alternating current. This alternating current is then transmitted from the alternator to the rectifier where it is converted to direct current. These alternators employ a three-phase stator winding in which the phase windings are electrically 120 degrees apart. The rotor consists of a field coil encased between interleaved sections producing. When the rotor is energized, a magnetic field with alternate north and south poles is created. By rotating the rotor inside the stator the alternating current is induced in the stator windings. This alternating current is rectified (changed to D.C.) by silicon diodes and brought out to the output terminal of the alternator. DIODE RECTIFIERS Six silicon diode rectifiers are used and act as electrical one-way valves. Three of the diodes have ground polarity and are pressed or screwed into a heat sink which is grounded. The other three diodes (ungrounded) are pressed or screwed into and insulated from the end head; these diodes are connected to the alternator output terminal. Since the diodes have a high resistance to the flow of current in one direction and a low resistance in the opposite direction, they may be connected in a manner which allows current to flow from the alternator to the battery in the low resistance direction. The high resistance in the opposite direction prevents the flow of current from the battery to the alternator. Because of this feature no circuit breaker is required between the alternator and battery. Page 7677 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 5010 Each user will be required to accept the following agreement each time the KeyCode application is used. Key Code User Agreement - Key codes are proprietary information belonging to General Motors Corporation and to the vehicle owner. - Unauthorized access to, or use of, key code information is unlawful and may subject the user to criminal and civil penalties. - This information should be treated as strictly confidential and should not be disclosed to anyone unless authorized. I will ensure that the following information is obtained prior to releasing any Key Code information: 1. Government issued picture ID (Drivers License) 2. Registration or other proof of ownership. Registration should have normal markings from the Province that issued the registration and possibly the receipt for payment recorded as well. Important - GM takes this agreement seriously. Each user must be certain of vehicle ownership before giving out key codes. - When the ownership of the vehicle is in doubt, dealership personnel should not provide the information. Key code requests should never be received via a fax or the internet and key codes should never be provided to anyone in this manner. A face to face contact with the owner of the vehicle is the expected manner that dealers will use to release a key code or as otherwise stipulated in this bulletin or other materials. - Key codes should NEVER be sent via a fax or the internet. - Each Dealership should create a permanent file to document all KeyCode Look Up transactions. Requests should be filed by VIN and in each folder retain copies of the following: - Government issued picture ID (Drivers License) - Registration or other proof of ownership. - Copy of the paid customer receipt which has the name of the employee who cut and sold the key to the customer. - Do not put yourself or your Dealership in the position of needing to "explain" a KeyCode Look Up to either GM or law enforcement officials. - Dealership Management has the ability to review all KeyCode Look-Up transactions. - Dealership KeyCode documentation must be retained for two years. Frequently Asked Questions (FAQs) for GM of Canada Dealers How do I request a KeyCode for customer owned vehicle that is not registered? Scrapped, salvaged or stored vehicles that do not have a current registration should still have the ownership verified by requesting the vehicle title, current insurance policy and / or current lien holder information from the customers financing source. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. In these cases, a short description of the vehicle (scrapped, salvaged, etc.) and the dealership location should be kept on file. Any clarifying explanation should be entered into the comments field. How do I document a KeyCode request for a vehicle that is being repossessed? The repossessor must document ownership of the vehicle by providing a court ordered repossession order and lien-holder documents prior to providing key code information. Copies of the repossessors Drivers License and a business card should be retained by the dealership for documentation. What do I do if the registration information is locked in the vehicle? Every effort should be made to obtain complete information for each request. Each Dealership will have to decide on a case by case basis if enough information is available to verify the customer's ownership of the vehicle. Other forms of documentation include vehicle title, insurance policy, and or current lien information from the customers financing source. Dealership Management must be involved in any request without complete information. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. Can I get a print out of the information on the screen? It is important to note that the Key Code Look Up Search Results contain sensitive and/or proprietary information. For this reason GM recommends against printing it. If the Search Results must be printed, store and/or dispose of the printed copy properly to minimize the risk of improper or illegal use. Who in the dealership has access to the KeyCode application? Dealership Parts Manager (or assigned management) will determine, and control, who is authorized to access the KeyCode Look Up application. However, we anticipate that dealership parts and service management will be the primary users of the application. The KeyCode Look Up application automatically tracks each user activity session. Information tracked by the system includes: User name, User ID, all other entered data and the date/time of access. Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Page 184 Engine Control Module: Component Tests and General Diagnostics ECM QDR Check Procedure ECM QDR Check Procedure Page 8062 Speedometer Head: Service and Repair Fig. 47 Speedometer Calibration Service Kit. Fig. 48 Instrument Cluster Connections For Speedometer Calibration. Locations ABS Main Relay: Locations EHCU Module Mounting The relay is located inside the Electro-Hydraulic Control Unit EHCU, also know as the Brake Pressure Modulator Valve (BPMV). Page 1255 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Page 7283 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 3062 Vehicle Speed Sensor: Service and Repair 1. Disconnect vehicle speed sensor electrical connector. 2. Remove sensor attaching bolt. 3. Using speed sensor remover and installer, tool No. J 38417, remove sensor, then O-ring seal. 4. Reverse procedure to install, coating the new O-ring seal with transmission fluid. Torque attaching bolt to 97 inch lbs. Page 3606 Ignition Control Module: Service and Repair Typical Distributor Components REMOVE OR DISCONNECT NOTE It is not necessary to remove ignition distributor assembly from engine. - Distributor cap and rotor. - Connectors from module. - Two module attaching screws. - Lift module from housing and remove. INSTALL OR CONNECT NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. - Module onto housing. - Module attaching screws. Tighten to 2 Nm (18 lb.in.) - Connectors to module. - Rotor and cap. Page 1813 3. Engine mounting through-bolts. -Tighten through-bolts or nuts to 70 Nm (52 ft.lbs) -Lower the vehicle. Fig. 2 Rear Engine Mount Installation. Except Bravada Fig. 3 Rear Engine Mount Installation. Bravada REAR MOUNTING REPLACEMENT Remove or Disconnect -Support the rear of the engine to relieve the weight on the rear mountings. Page 1472 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Page 3253 - Shell - Shell-Canada - Entec Stations located in the greater Montgomery, Alabama area. - MFA Oil Company located throughout Missouri. - Kwik Trip, Inc. in Minnesota and Wisconsin and Kwik Star convenience stores in Iowa. The Somerset Refinery, Inc. at Somerset Oil stations in Kentucky. Aloha Petroleum - Tri-Par Oil Company - Turkey Hill Minit Markets - Texaco - Petro-Canada - Sunoco-Canada - Road Ranger located in Illinois, Indiana, Iowa, Kentucky, Missouri, Ohio and Wisconsin What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent requirements imposed by the EPA. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began on May 3, 2004 and many fuel marketers have joined the program and have introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Where Can I find the Latest Information on TOP TIER Fuel and Retailers? On the web, please visit www.toptiergas.com for additional information and updated retailer lists. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: Audi, BMW, General Motors, Honda, Toyota and Volkswagen. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Disclaimer Page 2132 Distributor: Service and Repair Distributor Shaft, Pole Piece & Pickup Coil Typical Distributor Components REMOVE/DISCONNECT 1. With distributor removed, disconnect wires at module terminals 2. Roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. INSTALL/CONNECT 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Page 7689 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 4713 - Verify the Leading and Trailing shoes are installed in the correct relationship. - Any contamination should be removed from the new shoes immediately. If very light hand sanding will not remove the contamination the shoes should be discared. - When replacing shoes/linings or drums always replace both sides per axle. If only one side is replaced a steering pull may develop during braking. - If brake hardware is being replaced, verify that both the color and shape of the new springs match the old springs. - Prior to reinstalling the drum, the automatic adjuster will need to be backed off to accommodate for the increased thickness of the new shoes/linings. Page 7052 PAINT air dry only Note: Only items marked with an asterisk are "add" conditions to the Major Operation being performed. Removal time for all other items listed is included in the refinish time. LIGHT DUTY TRUCKS C/K TRUCKS Grille Front bumper filler panel Antenna Tail lamps Door edge guards Metal wheel opening moldings *Roof marker lamps "Luggage rack *West coast style mirrors "Stripes Emblems/decals if necessary Swing out windows/seals Tail gate handle bezel S/T TRUCKS Windshield molding Bumper filler panels, Ft./Rr. Wiper arms Antenna Wheel opening moldings Cowl vent grille Door edge guards Side view mirrors Tail lamps *Wind deflector Rear Window (Jimmy) *Luggage rack *Stripes Emblems/decals if necessary Swing out windows/seals *Spare tire carrier and latch-external mount (Jimmy) M/L VANS Windshield molding Wheel opening moldings Headlamp bezels Antenna Tail lamps Door edge guards *Luggage rack *Stripes Emblems/decals if necessary R/V TRUCKS Wiper arms Cowl vent grille Antenna Tail lamps Hood ornaments Wheel opening moldings Side view mirrors Grille and headlamp bezels Page 8569 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 2287 Engine Sensor Locations. LH Front Of Engine Applicable to: Except 4.3L/V6-262 HP & 4.3L/V6-262 Turbo Engines Page 3757 PROM - Programmable Read Only Memory: Description and Operation MEMCAL CAUTION: If the COMPUTER is found to be defective and needs replacement, remove the old MEMCAL and place it into the replacement computer. When replacing the COMPUTER always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: The MEMCAL assembly contains both the functions of the PROM and the CALPAK. Like the PROM, it contains the calibrations needed for a specific vehicle. It also is the fuel back up control for the computer should it become damaged or faulty. Locations Vehicle Speed Sensor/Transducer - Cruise Control: Locations Electronic Control Module (ECM) & Vehicle Speed Sensor Buffer (DRAC) Behind RH Side Of I/P Page 6029 II. OVER TORQUING OF WHEEL NUTS: 1. A TORQUE WRENCH MUST BE USED to insure that the wheel nuts are tightened to specification. This should be done in two steps using the star pattern. First, snug the nuts down by hand. Then, using the star pattern and a torque wrench, tighten the wheel nuts to about half the final torque. Finally, tighten the wheel nuts to specification using the star pattern and a torque wrench. 2. NEVER use lubricants or penetrating fluids on wheel studs, nuts, or mounting surfaces, as this can raise the actual torque on the nut without a corresponding torque reading on the wrench. Wheel nuts, studs, and mounting surfaces must be clean and dry. Page 8014 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 4372 Wheel Bearing: Adjustments Four Wheel Drive - 4WD FRONT WHEEL BEARINGS ADJUSTMENT 4 X 2 MODELS 1. Raise and support front of vehicle. 2. Remove hub dust cover, then the cotter pin. 3. While rotating wheel assembly in forward direction, torque spindle nut to specification to fully seat the bearings. 4. Loosen nut to the ``just loose'' position, then tighten the spindle nut finger tight. 5. If either spindle hole does not line up with a spindle nut slot, back off spindle nut not more than 1/2 nut flat. 6. Install new cotter pin, then measure hub endplay. Endplay should be .001-.005 inches when properly adjusted. 7. Install hub dust cover and lower vehicle. 4 X 4 MODELS These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Page 1210 Intake Air Temperature (IAT) Sensor Intake Air Temperature (IAT) Sensor 4.3W Page 186 ECM QDR Check Procedure Page 2397 Catalytic Converter: Testing and Inspection NOTE Proper diagnosis for a restricted exhaust system is essential before any components are replaced. The following procedure(s) may be used for diagnosis: Exhaust System Check CHECK AT A.I.R. PIPE - Remove the rubber hose at the exhaust manifold A.I.R. pipe check valve and remove check valve. - Connect a fuel pump pressure gauge to a hose and nipple from a Propane Enrichment Device. - Insert the nipple into the exhaust manifold A.I.R. pipe. CHECK AT 02 SENSOR - Carefully remove O2 sensor. - Install Exhaust Backpressure Tester in place of 02 sensor. - After completing the diagnosis described below, be sure to coat threads of 02 sensor with anti-seize compound prior to re-installation. DIAGNOSIS - With the engine idling at normal operating temperature, transaxle in park or neutral, observe the exhaust system backpressure reading on the gauge. The reading should not exceed .5 psi or 3.4 kPa. Increase engine speed to 3000 rpm and observe gauge. The reading should not exceed .75 psi or 5 kPa. - If the backpressure exceeds the given specifications, a restricted exhaust system is indicated. - Inspect the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure. - If there are no obvious reasons for the excessive backpressure, a restricted catalytic converter should be suspected, and replaced. WITH VACUUM GAUGE Engine at normal operating temperature: Connect a vacuum gauge to any convenient vacuum port on intake manifold. - Run engine at 1000 rpm and record vacuum reading. - Increase rpm slowly to 2500 rpm. Note vacuum reading at a steady 2500 rpm - If vacuum at 2500 rpm decreases more than 3" Hg, from reading at 1000 rpm, the exhaust system should be inspected for restrictions - Disconnect exhaust pipe from engine and repeat Step 2 & 3. If vacuum still drops more than 3" Hg, with exhaust disconnected, check for exhaust manifold restriction and valve timing. Page 7402 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Exhaust - Noise/Growl From Muffler Muffler: Customer Interest Exhaust - Noise/Growl From Muffler Number: 92-108-6F Section: 6F Date: FEB. 1992 Corporate Bulletin No.: 166606 ASE No.: A1,A8 Subject: NOISE/GROWL FROM MUFFLER Model and Year: 1992 S/T 4-DOOR TRUCKS WITH 4.3L TBI ENGINE Some owners of 1992 S/T four door utility vehicles with a 4.3L TBI engine (VIN code Z) built between the VIN breakpoints listed below may experience loud or noisy mufflers. This is due to the muffler's tuning tube being built out of manufacturers specifications. To correct this condition, replacement of the muffler is required. VEHICLES INVOLVED: VIN From SOP 1992 to N2113412 SERVICE PROCEDURE: Removing Exhaust Parts CAUTION: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury Using a penetrating oil on the threads of U-bolts can assist in the removal of the exhaust components. Installing Exhaust Parts When installing a new muffler and tailpipe, on any model, check for proper alignment. Rattles and noise vibrations in the exhaust system are usually caused by a misalignment of parts. When aligning the system, leave all bolts or nuts loose until all parts are properly aligned, then tighten working from the front to rear. Exhaust system hangers, hanger brackets, and clamps which are damaged should be replaced to maintain exhaust system alignment. Refer to S/T Service Manual section 6F Exhaust System for additional information. SERVICE PARTS INFORMATION Part Number Description 15662525 Muffler 15662531 Pipe Assembly 15595048 Clamp Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L2584 Use applicable labor time guide for labor hours. Page 4582 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 7107 Note: Chemical stripping is not recommended because of negative impact to moldings, non-metal components, ELPO and environmental concerns. 4. Blow off with air to remove all dirt and sanding residue from cracks and vehicle surface. 5. Clean sanded surface with an appropriate wax and grease remover. 6. Tack wipe entire area to be primed. 7. Spray entire prepared area with a coat of anti-corrosion primer to ensure maximum adhesion and corrosion resistance. Be sure to cover any bare metal surfaces exposed during the sanding operations. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 615S/616S, BASE DE17/PR8O/DA18, PPG DP4O/DP401, or equivalent. V.O.C. materials would be: DuPont 615S/616S, BASF DE15/PA16/PRB0, PPG DCP21/DCX211 or equivalent. 8. Apply two to three medium wet coats of primer surfacer to the primed surface of the vehicle, following the manufacturer's instructions for application and film build requirements. Important Failure to apply primer surfacer will likely result in future delamination. Typical materials for this application would be: DuPont 1120S/1130S/1125S, BASF DP20/PR80/PH36, PPG K36/DT870/K201, or equivalent. V.O.C. materials would be: DuPont 210S, BASF HP400, PPG DCP21/DCX211, or equivalent. 9. After allowing adequate drying time, wet sand with 400 grit (or finer) or dry sand with 320 grit (or finer) sandpaper. 10. Repeat steps 4 through 6. 11. Apply a medium coat of corrosion resistant primer sealer (tintable base) to the entire surface to be refinished. This will provide maximum adhesion, uniform color coating and corrosion protection to areas "sanded through" during wet sanding. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 2610S/2605S, BASF DP21/DH6O/PR80, PPG DP40/DP402 or equivalent. V.O.C. materials for this application would be: DuPont 21255, PPG DPW1834 or equivalent. 12. Apply two to three medium wet coats of color (or until primer color is hidden). Follow manufacturer's instructions and recommended dry times. 13. If vehicle has basecoat/clearcoat paint, apply clearcoat. Follow manufacturer's instructions and recommended dry times. 14. After sufficient air or force dry time, unmask the vehicle. 15. Finesse/polish as required. 16. Reinstall all previously removed items. 17. Wash and prepare the vehicle for delivery. HARDWARE ITEMS REMOVAL LIST Note: Some technicians may apply a small cord (wire, plastic tube, etc.) behind or underneath moldings that remain on the vehicle to improve sanding and painting. If the vehicle paint system is baked with cord in place, damage to some moldings may occur. If this technique is used, DO NOT BAKE PAINT air dry only Note: Only items marked with an asterisk are "add" conditions to the Major Operation being performed. Removal time for all other items listed is included in the refinish time. LIGHT DUTY TRUCKS C/K TRUCKS Grille Front bumper filler Page 60 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Locations Engine Coolant Temperature (ECT) W Page 1683 Connecting Rod Bearing: Specifications Bearing Undersize Availability Main bearings are available in standard size and undersizes of .001, .002, .009, .010 and .020 inch. Connecting rod bearings are available in standard size and .001 and .002 inch undersize for use with new and used standard size crankshafts and .010 and .020 inch undersize for use with reconditioned crankshafts. Page 8125 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 6611 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Clutch Pedal Switch Clutch Switch: Locations Clutch Pedal Switch Brake Pedal Switches. On Clutch Pedal Support Page 4839 Vacuum Brake Booster: Testing and Inspection Delco-Moraine Brake Boosters Brakes Grab 1. Faulty control valve. 2. Broken or damaged hydraulic brake lines. 3. Faulty master cylinder seals. 4. Cracked master cylinder casting. 5. Air in hydraulic system. Hard Pedal 1. Internal vacuum leak. 2. Faulty control valve. 3. Broken or damaged hydraulic brake lines. 4. Collapsed or damaged vacuum hose. 5. Plugged or loose vacuum fitting. 6. Bad stud welds on front or rear housing on power head. 7. Faulty booster diaphragm. 8. Restricted air filter element. 9. Worn or distorted reaction plate or levers. 10. Cracked or broken power pistons or retainers. Slow or No Release 1. Faulty pushrod adjustment. 2. Binding linkage. 3. Blocked passage in power piston. 4. Air valve sticking shut. 5. Broken piston return spring or air valve spring. Page 7326 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 3431 CMFI Intake Manifold Sensors/Valves Page 7642 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Page 4071 than a standard fan. These benefits are possible through the addition of a thermostatic clutch to the fan drive. When the engine is cool the clutch allows the fan to "slip" or turn at a speed slower than the engine. By turning at a slower speed the fan uses less horsepower, which saves fuel, and is quieter. When the engine temperature reaches a preset temperature, the fan "engages" and turns at the same speed as the engine. "Engagement" of the fan provides increased airflow through the radiator to cool the engine. As the airflow increases, fan operation becomes clearly audible. This increase in noise can easily be mistaken for an increase in engine RPM and may be incorrectly blamed on the automatic transmission. When operating an unloaded vehicle in cooler ambient temperatures, the thermostatic clutch usually won't engage. However, if the vehicle is pulling a trailer, heavily loaded or operated at high ambient temperatures the thermostatic clutch may cycle on and off as the engine temperature rises and falls. The sound of fan operation under the conditions described above is a sign that the cooling system on your vehicle is working correctly. Replacement or modification of cooling system or transmission parts will not change or reduce the noise level. Attempts to reduce this noise will only give you, the customer, a false sense of vehicle unreliability and the inconvenience of having your vehicle out of service. Page 1042 accumulating at least 200 miles, call the appropriate marketing division technical assistance group. CORRECTION - CATEGORY B: Valve Train Chatter, Tick, or Click. For 1992 or 1993 vehicles equipped with a Romulus built (adjustable lash) LB4 (VIN Z 4.3L V6) engine, adjust valve lash. Bulletin 376107 provides information on this procedure and on how to identify Romulus-produced engines. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts are expected to be available on August 30, 1993. WARRANTY INFORMATION: Labor Operation: J0950 - Filter and Oil Replace Labor Time: Use published labor time. For 1992 LB4 vehicles: Labor Operation: T0500 - PROM replace Labor Time: 0.5 hours Tires - Correct Inflation Pressure Information Tires: All Technical Service Bulletins Tires - Correct Inflation Pressure Information INFORMATION Bulletin No.: 00-00-90-002J Date: January 28, 2009 Subject: Information on Proper Tire Pressure Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2009 and Prior HUMMER H2, H3, H3T 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years and clarify additional information. Please discard Corporate Bulletin Number 00-00-90-002I (Section 00 - General Information). Important: ^ Adjustment of tire pressure for a customer with a Low Tire Pressure Monitor (TPM) light on and no codes in the TPM system is NOT a warrantable repair. Claims to simply adjust the tire pressure will be rejected. ^ ALL tires (including the spare tire) MUST be set to the recommended inflation pressure stated on the vehicle's tire placard (on driver's door) during the PRE-DELIVERY INSPECTION (PDI). Recommended inflation pressure is not the pressure printed on tire sidewall. ^ Tires may be over-inflated from the assembly plant due to the mounting process. ^ Generally a 5.6°C (10°F) temperature change will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure change. ^ 2008-2009 HUMMER H2 Only - The H2 comes standard with Light Truck "D" Load Range tires with a recommended cold inflation pressure of 289 kPa (42 psi). These tires will alert the driver to a low pressure situation at roughly 262 kPa (38 psi) due to a requirement in FMVSS 138 which specifies a Minimum Activation Pressure for each tire type. This creates a relatively narrow window of "usable" pressure values and the warning will be more sensitive to outside temperature changes during the colder months. As with other cold temperature/tire pressure issues, there is nothing wrong with the system itself. If a vehicle is brought in with this concern, check for tire damage and set all tires to the Recommended Cold Inflation Pressure shown on the vehicle placard. Accurate tire pressures ensure the safe handling and appropriate ride characteristics of GM cars and trucks. It is critical that the tire pressure be adjusted to the specifications on the vehicle¡C■s tire placard during PDI. Ride, handling and road noise concerns may be caused by improperly adjusted tire pressure. The first step in the diagnosis of these concerns is to verify that the tires are inflated to the correct pressures. The recommended tire inflation pressure is listed on the vehicle¡C■s tire placard. The tire placard is located on the driver¡C■s side front or rear door edge, center pillar, or the rear compartment lid. Tip ^ Generally a 5.6°C (10°F) temperature increase will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure increase. ^ The definition of a "cold" tire is one that has been sitting for at least 3 hours, or driven no more than 1.6 km (1 mi). ^ On extremely cold days, if the vehicle has been indoors, it may be necessary to compensate for the low external temperature by adding additional air to the tire during PDI. ^ During cold weather, the Tire Pressure Monitor (TPM) indicator light (a yellow horseshoe with an exclamation point) may illuminate. If this indicator turns off after the tires warm up (reach operating temperature), the tire pressure should be reset to placard pressure at the cold temperature. ^ The TPM system will work correctly with nitrogen in tires. ^ The TPM system is compatible with the GM Vehicle Care Tire Sealant but may not be with other commercially available sealants. Important: ^ Do not use the tire pressure indicated on the tire itself as a guide. Page 5896 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Page 7029 On a clean surface, at or above room temperature, firmly apply a 2" wide piece of masking tape and pull upward quickly. DO NOT USE duct tape, cloth backed tape or other aggressive tapes. If the colorcoat flakes or peels away from the ELPO (leaving the ELPO intact) the colorcoat is delaminating and the vehicle should be repaired using the "Paint Repair Procedure" contained in this bulletin. This test SHOULD ONLY BE APPLIED TO A VEHICLE SHOWING THE CONDITION, (peeling/delamination) and NOT in areas of stone chipping or other obvious damage. These "other" conditions should be repaired following standard paint repair procedures. CORRECTION Refinish the ENTIRE BODY ABOVE THE BODY SIDE MOLDINGS using the following repair procedure. It is important that ALL surfaces above the body side moldings (including recessed areas around door handles) be refinished, as these surfaces may show the same DELAMINATION (peeling) condition at a later date. Note: Many vehicles have some type of plastic exterior body panels (cowl vent grilles, fascias, front end panels, rear fenders, etc.). These panels are not subject to DELAMINATION and therefore do not require refinishing. If painting of these panels is required for color uniformity, scuff sand and colorcoat only (and clearcoat if basecoat/clearcoat system is used). Note: Two tone lines, feature lines or body side molding treatments near mid-door height are appropriate break lines. If no such convenient break lines are present, the entire panel above the next lower break line must be refinished and the portion of the panel below that break line should be COLORCOATED ONLY (and clearcoated if basecoat/clearcoat system is used) for color uniformity of the repair. Note: Pickup boxes which are covered by caps, bedliners or tonneau covers do not receive direct exposure to sunlight, and normally would not be repaired under this procedure. However, if the inside of the box has been uncovered and experienced DELAMINATION, use the appropriate Labor Operation Number. Note: Certain two tone applications on trucks using the high potential colors (Blues, Grays and Silvers) may require that only portions of the vehicle surface be refinished. Examples would be: Example 1. Blues, Grays and Silvers as "insert colors" on vertical surfaces with other, non-high potential colors above the insert (or break line). Action: Refinish the "insert color" only, between the break line and body side molding (or to the lower feature line on certain vehicles). Example 2. Blues, Grays and Silvers on surfaces above the break line with other, non-high potential colors as "insert colors". Action: Refinish the surfaces above the "insert color" or break line only. Example 3. Blues, Grays and Silvers used as both the primary and "insert colors". Action: Refinish both high potential color surfaces above the body side moldings (or to the lower feature line on certain vehicles). Vehicles should be repaired with the same type materials they were manufactured with; repair basecoat/clearcoat with basecoat/clearcoat materials and monocoat with monocoat. PAINT REPAIR PROCEDURE 1. Some vehicle components will be removed from the vehicle while others will require masking. The list located at the end of this bulletin will establish the removal items. Items not found on the list and non-repair areas are to be masked. 2. Prior to removing the paint finish, clean the area to be refinished with an appropriate wax and grease remover to remove any contaminants. 3. Remove the original finish of paint down to the ELPO primer surface using an orbital D.A. sander, leaving the ELPO surface intact. This can be done in "stages" using 80 grit (or finer) discs to remove the majority of coating, followed with 180 grit (or finer) discs to remove the remainder of material down to the ELPO surface and any chalky residue or degraded ELPO that may remain. Avoid sanding through ELPO to bare metal in order to retain maximum corrosion protection. - An alternative in some geographic areas may be plastic media blasting such as may be provided by members of: - Dry Stripping Facilities Network 1-800-634-9185 * Page 5309 For vehicles repaired under warranty, use the table. Disclaimer Linear EGR - Installation Procedure Revision EGR Valve: Technical Service Bulletins Linear EGR - Installation Procedure Revision FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 51-65-32 DATE: May, 1995 SUBJECT: Section 6E3, 9, 9C, 9A - Driveability and Emissions - Revised Linear EGR installation Procedure MODELS: 1992-95 Chevrolet and GMC Truck M/L Vans 1992-95 Chevrolet and GMC Truck S/T Models 1993-95 Chevrolet and GMC Truck C/K Models 1994-95 Chevrolet and GMC Truck G Vans 1994-95 Chevrolet and GMC Truck P3, P/G Chassis 1992-93 Oldsmobile Bravada with 4.3L, 7.4L Engines (VINs W, N - RPOs L35, L19) and (VIN Z - RPO LB4 - with California Emissions) This service bulletin revises the Linear EGR installation Procedure, in the following service manuals: 1992-93 Oldsmobile Bravada Service Manual, page 6E3-C7-6. 1992-93 Light Duty Truck, Fuel and Emissions Service Manual, pages 9-19 and 90-6. 1994-95 S/T Driveability Emissions and Electrical Diagnosis Service Manual and the 1994 S/T Truck Supplement with RPO CTF, page 9A-8. 1994-95 C/K, M/L, G Van and P/G and P3 Chassis Driveability Emissions and Electrical Diagnosis Service Manuals, page 9A-6. The revised procedure is as follows: Install or Connect 1. EGR valve and new gasket. 2. Valve to flange bolts. Tighten Tighten bolts in two steps. a. The first step to 10 Nm (89 lb.in.). b. The second step to 25 Nm (18 lb.ft.). 3. Electrical connector. Page 2601 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Page 5787 2. Fill the injury (puncture) to keep moisture out. 3. Seal the inner liner with a repair unit to prevent air loss. External Inspection 1. Prior to demounting, inspect the tire surface, the valve and the wheel for the source of the leak by using a water and soap solution. Mark the injured area and totally deflate the tire by removing the valve core. 2. Demount the tire from the wheel and place the tire on a well-lighted spreader. Internal Inspection 1. Spread the beads and mark the puncture with a tire crayon. 2. Inspect the inner tire for any signs of internal damage. 3. Remove the puncturing object, noting the direction of the penetration. 4. Probe the injury with a blunt awl in order to determine the extent and direction of the injury. 5. Remove any loose foreign material from the injury. 6. Punctures exceeding 6.35 mm (1/4") should not be repaired. Cleaning 1. Clean the area around the puncture thoroughly with a proper liner cleaner, clean cloth and a scraper. This step serves to remove dirt and mold lubricants to insure proper adhesion and non-contamination of the buffing tool. 2. Refer to information on the product or manufacturer's Material Safety Data Sheet and follow guidelines for handling and disposal. Clean the Injury Channel Page 5826 1. Center the repair unit over the injury as a reference and outline an area larger than the unit so that buffing will not remove the crayon marks. 2. Remove the repair unit. 3. DO NOT overlap previous or multiple repair units. 4. Consult your repair material supplier for proper repair unit selection. Buffing 1. To prevent contamination and preserve the outline, buff within the marked area thoroughly and evenly with a low speed buffing tool using a fine wire brush or gritted rasp. 2. Buff to a smooth velvet surface (RMA #1 or #2 buffed texture). 3. Use caution not to gouge the inner liner or expose casing fabric. 4. Remove any buffing dust with a vacuum cleaner. 5. Consult your repair material supplier for a proper buffing tool. Cementing Apply chemical cement according to the repair material manufacturer's procedures. Repair Unit Application Page 6230 screw into the remover body to remove the clutch plate and hub assembly. 4. Remove the shaft key and retain for reassembly. Install or Connect Shaft Key, Clutch Plate/Hub Assembly 1. Install the shaft key into the hub key groove. Allow the key to project approximately 3.2 mm (1/8") out of the keyway. The shaft key is curved slightly to provide an interference fit in the hub key groove. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the clutch plate and hub assembly. 3. Align the shaft key with the shaft keyway and place the clutch plate and the hub assembly onto the compressor shaft. NOTICE: Do not drive or pound on the clutch hub or shaft. Internal damage to compressor may result. Page 7596 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 6588 Symbol Identification Page 4326 Pinion Gear: Service and Repair Corporate and Eaton 9 1/2 Inch Ring Gear PINION DEPTH ADJUSTMENT Fig. 9 Pinion Depth Gauge Installation If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly tool No. J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION INSTALLATION 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. Page 1288 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 3581 Ignition Control Module: Description and Operation PURPOSE The distributor reference signal provides the ECM with both engine RPM and crankshaft position information. This enables the ECM to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the ECM receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the ECM will not operate the injector. Page 7633 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 5381 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 5362 Fuse And Circuit Breaker Identification Page 8311 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 7510 Page 5668 Fig. 9 Recirculating ball installation Fig. 2 Rack piston plug removal Fig. 10 Ball guide installation Fig. 11 Needle bearing installation Page 6921 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 4555 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Specifications Hose/Line HVAC: Specifications Refrigerant Hose-to-Condenser .............................................................................................................................................................. 24 Nm (18 ft. lbs.). Refrigerant Hose-to-Compressor Bolt ................................................................................................................................................... 34 Nm (25 ft. lbs.). Refrigerant Hose-to-Accumulator .......................................................................................................................................................... 41 Nm (30 ft. lbs.). Page 7474 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Description and Operation Fillpipe Restrictor: Description and Operation Fuel Filler Neck Fuel Door And Restrictor (Typical) Purpose To prevent refueling with leaded fuel, the fuel filter neck has a built-in restrictor and deflector. The opening in the restrictor will accept only the smaller unleaded gasoline fuel nozzle which must be fully inserted to bypass the deflector. Page 6676 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 5511 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 7090 M - Miracryl(R) Super Max(R) FLEXIBLE FINISHES When spraying flexible plastic parts, use the following recommendations: Elastifier additive 521-111 for Vinyl application when using Glasurit(R) 54 and 21 lines. 891 Flex Agent for Vinyl Application when using Alphacryl, Miracryl, Diamont 88(R), and Supreme Gold. DF-25 for Vinyl application when using Diamont Solo(R). NOTE: When using a basecoat/clearcoat system only use the flex agent in the clearcoat application. STONE CHIP PROTECTOR Glassohyd(TM) 1109-1240/6 Stone Chip Protector is a waterborne material which uses a durable, flexible plastic dispersion as its bonding media. This product is versatile in application and may be easily applied by spray, brush, or roller. When Glassohyd(TM) is completely cured, the material is resistant to water, gasoline, and oil. Glassohyd(TM) has excellent stone impact and corrosion resistance. Glassohyd(TM) Stone Chip Protector can be topcoated directly with 21-line or 54/94-line colors. DuPont refinished paints are available in: - L-Lucite(R) - Acrylic Lacquer - A-Centari(R) - Acrylic Enamel - J-Cronar(R) - Polyoxithane Enamel - K-ChromabaseTM - 350S - Flexlar(R) - Flexible Additive - 310S - Black - 1-2-3 Vinyl Lacquer - 330S - White - 1-2-3 Vinyl Lacquer - V-Lucite Vinyl Important Vinyl resin must be added to the base color when painting interior components. DuPont vinyl resin 304S (instrument panel). DuPont vinyl resin 305S (all remaining interior parts except seats). DuPont vinyl resin 306S (seats and vinyl roofs). When ordering DuPont paint, use "L", "A", "J", "K", or "V" with the appropriate DuPont Code. PPG (Ditzler) refinish paints are available in: - DDL - Duracryl(R) - Acrylic Lacquer or Acrylic Basecoat/Clearcoat - DBU - Deltron(R) - Basecoat/Clearcoat - DAR - Delstar(R) - Acrylic Enamel - DAU - Deltron(R) - Acrylic Urethane - UCV - Vinyl Colors - DX-369 - Flexative(R) - Flexible Finishes - DX-54 - Roadguard(R) - Road Abrasion Protection When ordering PPG (Ditzler) paint, use "DDL", "DBU", "DAR", "DAU", "UCV", "DX-54", or "DX-369" with appropriate Ditzler code. Page 3223 - Shell - Shell-Canada - Entec Stations located in the greater Montgomery, Alabama area. - MFA Oil Company located throughout Missouri. - Kwik Trip, Inc. in Minnesota and Wisconsin and Kwik Star convenience stores in Iowa. The Somerset Refinery, Inc. at Somerset Oil stations in Kentucky. Aloha Petroleum - Tri-Par Oil Company - Turkey Hill Minit Markets - Texaco - Petro-Canada - Sunoco-Canada - Road Ranger located in Illinois, Indiana, Iowa, Kentucky, Missouri, Ohio and Wisconsin What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent requirements imposed by the EPA. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began on May 3, 2004 and many fuel marketers have joined the program and have introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Where Can I find the Latest Information on TOP TIER Fuel and Retailers? On the web, please visit www.toptiergas.com for additional information and updated retailer lists. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: Audi, BMW, General Motors, Honda, Toyota and Volkswagen. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Disclaimer Page 2708 Distributor: Service and Repair Distributor Shaft, Pole Piece & Pickup Coil Typical Distributor Components REMOVE/DISCONNECT 1. With distributor removed, disconnect wires at module terminals 2. Roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. INSTALL/CONNECT 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Rocker Arm Nut Torque Rocker Arm Assembly: Specifications Rocker Arm Nut Torque VALVE ROCKER ARM NUT TORQUE Valve Rocker Arm Nuts ....................................................................................................................... ................................................ 27 Nm (20 lb. ft.). Page 5961 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Page 5077 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 6460 Control Cable REMOVE OR DISCONNECT 1. Screws (64). 2. Control assembly (63). NOTICE: Pull control assembly (63) out of the instrument panel far enough to reach the control cable assembly ends arid the blower switch electrical connector. 3. Electrical connection (82). 4. Control cables (60 and 65). 5. Blower switch if necessary. NOTICE: Remove the blower switch knob and spring clip, and remove the blower switch. Inspect - Electrical terminals for corrosion. Remove the corrosion or replace the component as necessary. - Temperature and mode levers for freedom of movement. Lubricate, repair or replace as necessary. - Control cable assemblies for kinks, binding and other damage. Repair or replace as necessary. INSTALL OR CONNECT 1. Heater blower switch if removed. - Hold the blower switch in position and install the spring clip. Page 5159 Fuse: Locations Inline Fuse, Underhood Lamp Between Underhood Lamp & Junction Block Page 6658 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by PROM/MEMCAL - Identification Marks Memory Calibration Unit: Technical Service Bulletins PROM/MEMCAL - Identification Marks File In Section: 6E - Engine Fuel & Emission Bulletin No.: 44-65-01 Date: October, 1994 Subject: New PROM/MEMCAL Identification Markings Models: 1995 and Prior Passenger Cars and Trucks Note: For the purposes of this document, the terms PROM and MEMCAL will be used interchangeably. To simplify identification of service PROMs. a new external marking format will be implemented. Parts manufactured after Sept. 1994 will feature these new markings. This change will place the full 8-digit service part number on the PROM, in place of the old 4-digit "EXTERNAL ID" number. In the past, parts and service personnel could not identify a PROM without using a cross-reference table that matched external IDs and service numbers. In the future, the cross-reference table will not be required for PROMs; parts will be ordered directly from the number appearing on the PROM. However, the label will retain the broadcast code alpha characters to allow continued use of cross-reference charts, if so desired. Old Marking Format: New Marking Format: ^ Ordering the above PROM from the old marking format would require using a cross-reference chart to determine a service part number, based on the BROAD CAST CODE and EXTERNAL ID NUMBERS. ^ To order from the new format, simply combine the 2nd and 3rd lines to form an 8-digit part number that can be directly ordered from SPO (number 16134624 in the above example). As these changes are phased into the parts inventory, it should be noted that dealers will continue to see parts with both formats for some time in the future. This is because: ^ Millions of vehicles have already been built with the old format. ^ SPO has existing stock of MEMCALs and PROMs with the old format. ^ PROMS with 7-digit part numbers (representing less than 10% of current part numbers) will continue to use the old format. The 7-digit part numbers are easily identified because they always begin with "122xxxx". Due to manufacturing processes, more than one 8-digit part number may appear on a MEMCAL. In this event, service personnel should use the label on the exterior cover of the MEMCAL assembly. To avoid confusion, only the service label will include the BROAD CAST CODE, consisting of letter characters (I.E., ARCL). Page 2244 IMPORTANT: To maintain a balanced fan assembly, align the yellow paint mark on the fan clutch with the yellow paint mark on the water pump hub. SERVICE PARTS INFORMATION Part Number Description 15672779 Fan Clutch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Page 7554 Vehicle Speed Sensor/Transducer - Cruise Control: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 5729 Brake Fluid - Level & Filling Recommendations Brake Fluid: Technical Service Bulletins Brake Fluid - Level & Filling Recommendations File In Section: 05 - Brakes Bulletin No.: 00-05-22-004 Date: May, 2000 INFORMATION Subject: Brake Fluid Level and Filling Recommendations Models: 2001 and Prior Passenger Cars and Trucks Many dealers and after-market repair shops advertise multi-point fluid "top-ups" in conjunction with oil changes or regular maintenance packages. These offers often include adding brake fluid to the master cylinder reservoir. There are only two reasons why the brake fluid level in the brake reservoir might go down. The first is that the brake fluid level goes down an acceptable level during normal brake lining wear. When the linings are replaced, the fluid will return to it's original level. The second possible reason for a low fluid level is that fluid is leaking out of the brake system. If fluid is leaking, the brake system requires repair and adding additional fluid will not correct the leak. If the system was properly filled during delivery of the vehicle, no additional fluid should be required under most circumstances between brake pad and/or shoe replacements. This information can be reinforced with the customer by referring them to the Brake Fluid section of their vehicle's Owner's Manual. Guidelines GM vehicles have incorporated a variety of brake fluid reservoir styles. The following guidelines are restricted to the plastic bodied fluid reservoirs and do not affect the original service recommendations for the older style metal bodied units. You may encounter both black plastic and translucent style reservoirs. You may have reservoirs with: ^ A MAX fill mark only ^ A MIN fill mark only ^ Both MAX and MIN marks The translucent style reservoirs do not have to have the covers removed in order to view the fluid level. It is a good practice not to remove the reservoir cover unless necessary to reduce the possibility of contaminating the system. Use the following guidelines to assist in determining the proper fluid level. Important: When adding brake fluid, use Delco Supreme II(R) Brake Fluid, GM P/N 12377967 or equivalent brand bearing the DOT-3 rating only. Important: At no time should the fluid level be allowed to remain in an overfilled condition. Overfilling the brake reservoir may put unnecessary stress on the seals and cover of the reservoir. Use the following guidelines to properly maintain the fluid level. If the reservoir is overfilled, siphon out the additional fluid to comply with the guidelines below. Important: If under any circumstance the brake fluid level is extremely low in the reservoir or the BRAKE warning indicator is illuminated, the brake system should be checked for leaks and the system repaired in addition to bringing the fluid level up to the recommended guidelines outlined below. A leaking brake system will have reduced braking performance and will eventually not work at all. Important: Some vehicles have reservoirs that are very sensitive to brake fluid levels and may cause the BRAKE indicator to flicker on turns as the fluid approaches the minimum required level. If you encounter a vehicle with this concern, increase the fluid level staying within the guidelines outlined below. ^ If the reservoir has a MAX level indicator, the reservoir should be returned to the MAX marking only at the time new brake pads and/or shoes are installed. If the reservoir fluid level is at the half-way point or above do not attempt to add additional brake fluid during routine fluid checks. ^ If the reservoir has both MAX and MIN indicators, the fluid level should be maintained above the MIN indicator during routine fluid checks and returned to the MAX indication only after new brake pads and/or shoes are installed. ^ For reservoirs with only a MIN indication, the fluid level should be maintained above the MIN indicator during routine fluid checks. Return the Page 5652 Fig. 1 Troubleshooting power steering system Excessive Wheel Kickback or Loose Steering 1. Air in power steering system. 2. Steering gear attachments loose. 3. Joints from column to steering gear loose. 4. Tie rod ends loose. 5. Wheel bearings worn. 6. Loose thrust bearing preload adjustment. 7. Low fluid level. Hard Steering or Lack of Assist 1. Brakes applied while turning steering wheel. 2. Joints from column to steering gear loose or worn. 3. Sticky steering gear valve. Description and Operation Brake Signal: Description and Operation PURPOSE The brake switch signals the control module to turn "OFF" the torque converter clutch when the brakes are applied. OPERATION The brake switch is normally closed. When the brake pedal is applied the switch will open, changing the signal to the control module. The control module uses this signal to de-energize the TCC solenoid when brake pedal is applied. LOCATION The brake switch is located on the brake pedal mounting bracket. Page 2184 Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Switch HP Engine LH Front Side Of Engine Front Of Intake Manifold Applicable to: 1992 4.3L/V6-262 HP Engine STD Engine Page 4259 Differential Axle Housing: Service and Repair GMC Single Speed Axle Refer to ``Chevrolet Full Floating Axles'' for axle housing replacement procedures, since procedures are identical for both axles. Page 2771 Engine Control Module: Description and Operation Powertrain Control Module (PCM) PURPOSE The Control Module is the control center of the fuel injection system. It constantly looks at the information from various sensors (inputs) and controls the systems (outputs) that affect vehicle performance. The control module also performs the diagnostic control moduletion of the system. It can recognize operational problems, alert the driver through the Malfunction Indicator Lamp (MIL) "Service Engine Soon" light on the instrument panel and store a Diagnostic Trouble Code(s) (DTC) in the control module memory. The DTC identifies the problem areas to aid the technician in performing repairs. OPERATION The control module is an electronic computer designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The control module can control these devices through the use of Quad Driver Modules (QDM). When the control module is commanding a device or a component "ON," the voltage potential of the output is "LOW" or near zero volts. When the control module is commanding a device or component "OFF," the voltage potential of the circuit will be "HIGH," or near 12 volts. The primary function of the QDM is to supply the ground for the component being controlled. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The control module has two parts for service: - Controller which is the control module without the PROM (MEM-CAL). - PROM (Programmable Read Only Memory) which is a separate memory calibrator unit Learning Ability The control module has a "learning" ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected, to clear diagnostic trouble codes or for other repairs. the "learning" process resets and begins again. A change may be noted in the vehicle's performance. To "teach" the vehicle, ensure the engine is at operating temperature. The vehicle should be driven at part throttle, with moderate acceleration and idle conditions until normal performance returns. NOTE The control module must be maintained at a temperature below 85°C (185°F) at all times. This is most essential if the vehicle is put through a baking process. The control module will become inoperative if it's temperature exceeds 85°C (185°F). It is recommended that temporary insulation be placed around the control module during the time the vehicle is in a paint oven or other high temperature processes. Page 6838 Technical Service Bulletin # 06027A Date: 070523 Campaign - Interior Front Door Handles Bulletin No.: 06027A Date: May 23, 2007 SPECIAL COVERAGE Subject: 06027A - SPECIAL COVERAGE ADJUSTMENT - CLASS ACTION SETTLEMENT - INTERIOR DOOR HANDLE SPRING BREAKAGE Models: 1982-1994 CHEVROLET S/T PICKUP AND UTILITY 1982-1994 GMC S/T PICKUP AND UTILITY, JIMMY 1991-1994 OLDSMOBILE BRAVADA INVOLVED IN SOUTH CAROLINA CLASS ACTION SETTLEMENT Supercede: The expiration date for this special coverage has been extended to December 31, 2007. The mailing of letters to customers was delayed. Letters will be mailed to customers on May 30, 2007. Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Condition Some customers of 1982-1994 Chevrolet S/T pickup and utility vehicles; 1982-1994 GMC S/T pickup and utility vehicles; and 1991-1994 Oldsmobile Bravada vehicles are entitled to the benefits of a class action settlement. The benefits are listed below and customers will be provided with a letter to present to dealers that details the remedy that they chose. Special Coverage Adjustment This special coverage covers the conditions described below until December 31, 2007. Customers may have any combination of the benefits listed below. Please see the customer's letter to determine the appropriate remedy. Reimbursement - Customers who have replaced an interior front door handle assembly have already submitted a request for reimbursement. GM is handling the reimbursements. There is no action required from the dealer. Replacement of broken interior front door handle assembly(s) - Some customers have chosen to receive a replacement interior front door handle assembly(s). Dealers are to provide the customer with the assembly(s) at no charge. The customer is to self-install or pay the dealer for the installation of the assembly(s). Application of lithium grease - Customers who have the original front door handle assembly(s) in which the spring is not broken, are entitled to have the spring(s) greased. Dealers are to apply lithium grease to the unbroken spring(s) of the original front door handle assembly(s) at no charge. Vehicles Involved Customers involved will present the dealer their vehicle with a letter that authorizes the repair. If the customer requests a new interior front door handle, dealer must verify it replaces a broken interior front door handle assembly. Page 3573 Ignition Coil: Locations Engine Wiring, RH Side Page 381 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 2121 Spark Plug Wire Routing 4.3W Page 8274 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 2425 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Heater Defroster Door Actuator Air Door Actuator / Motor: Locations Heater Defroster Door Actuator Heater & A/C Components, Instrument Panel Behind Center Of I/P Page 1233 5. Attach the valve pressure bleeding tools J39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (figure 3) and to the combination valve (figure 4). Tighten tool J39177 only finger tight. 6. Open the pressure bleeder tank valve. 7. Bleed each wheel in the following sequence: - Right rear - Left rear - Right front - Left front NOTE: Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. NOTE: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 8. Open the bleeder valve at least 3/4 of a turn and allow the fluid to flow until no air is seen in the fluid. Tighten the bleeder valve. 9. Repeat step 7 and 8 at each wheel cylinder/caliper until all the air is purged. 10. Disconnect the bleeder tank hose from the bleeder adaptor and remove the bleeder adaptor. 11. Fill the master cylinder to the proper level and replace lid. 12. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs.in.). 13. Remove the valve pressure bleeding tools J39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 14. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. IMPORTANT: DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 15. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. IMPORTANT: DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 16. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs.in.). 17. Remove the bleeder adaptor, if using the pressure bleed procedure (figure 1), and fill the master cylinder to the proper level with brake fluid. 18. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. IMPORTANT: MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 19. Repeat the entire brake bleed procedure if necessary. Manual Bleed Procedure When a pressure bleeder is not available, use the (two person) manual bleed procedure. One person will push on the brake pedal while the other person will open and close the bleed valves. IMPORTANT: You can expect to use two quarts of brake fluid to thoroughly bleed the system. Page 3746 [290] Spark knock. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [291] Spark knock. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [292] Spark knock (G055). USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [293] Spark knock (G043). USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [294] Stalling, tip-in hesitation/sag, rough idle, cold driveability. USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [295] Hard hot restart (requires rubber bumper pkg PN 25004553, and a pulsator package PN 25094266), or CODE 42, intermittent high idle, spark knock (G055). [296] USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [297] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [298] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [299] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [300] Spark knock. USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. Page 90 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Front Radio And I/P Speaker Wiring - Stereo Page 2596 EGR AND EVRV SOLENOID 4.3 L Page 663 CMFI Intake Manifold Sensors/Valves Page 436 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 978 This condition maybe attributed to belt interference between the water pump pulley and belt tensioner pulley (Figure 1) The belt tensioner pivots both directions from the center pivot axis which can result in the serpentine belt coming in contact with itself at the water pump pulley. To correct this condition, loosen the generator bracket bolts (3) and move the top of the bracket to its most outward position (Figure 1). This will move the tensioner pulley away from the water pump pulley increasing clearance, to eliminate contact. Tighten the generator bracket bolts after the bracket has been repositioned. NOTE: Some cleaning agents or mineral oils can attack the belt compound and should not be used in this location. This may be another contributor to premature wear. If a new serpentine belt is required for the chirping sound or premature wear. new accessory drive serpentine belts have been released to GMSPO. The new belts will supersede the existing part numbers. SERVICE PARTS INFORMATION: PART NO. DESCRIPTION QTY. 10210382 Belt-Fan w/o C60, C69 1 10210383 Belt-Fan w C60, C69 1 S/T and C/K An improved belt is available for use on 1990 through 1993 S/T and C/K trucks with L35, LB4, L03, or LO5 engines equipped with C60 (air conditioning) but without K19 (A.I.R.). The new belt is less prone to "chirping." If, after performing standard diagnostic procedures, a serpentine belt replacement is required, use P/N 10189265. NOTE: P/N 10189265 replaces P/N 10069211. Parts are currently available from GMSPO. WARRANTY INFORMATION: Page 5512 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 4037 through the cooler. ^ Converter bearing noise determined by noise from the bell housing area in Drive or Reverse at idle. The noise is gone in Neutral and Park. ^ If silicon from the viscous clutch is found in the lower pan (4T80-E ONLY). Disclaimer Page 1775 This condition may be attributed to belt interference between the water pump pulley and belt tensioner pulley (Figure 1). The belt tensioner pivots both directions from the center pivot axis which can result in the serpentine belt coming in contact with itself at the water pump pulley. To correct this condition, loosen the generator bracket bolts (3) and move the top of the bracket to its most outward position (Figure 1). This will move the tensioner pulley away from the water pump pulley increasing clearance, to eliminate contact. Tighten the generator bracket bolts after the bracket has been repositioned. **NOTE: Some cleaning agents or mineral oils can attack the belt compound and should not be used in this location. This may be another contributor to premature wear. If a new serpentine belt is required for the chirping sound or premature wear, new accessory drive serpentine belts have been released to GMSPO. The new belts will supersede the existing part numbers. SERVICE PARTS INFORMATION: Part Number Description Qty. 10210382 Belt-Fan w/o C60, C69 1 10210383 Belt-Fan w C60, C69 1 S/T and C/K An improved belt is available for use on 1990 through 1993 S/T and C/K trucks with L35, LB4, L03, or L05 engines equipped with C60 (air conditioning) but without K19 (A.I.R.). The new belt is less prone to "chirping." If, after performing standard diagnostic procedures, a serpentine belt replacement is required, use P/N 10189265. NOTE: P/N 10189265 replaces P/N 10069211. Parts are currently available from GMSPO. WARRANTY INFORMATION: IP Dimmer Control - Proper Setting Dimmer Switch: Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Page 1215 Adapter, High Side - 91172093 0-Rings: Compressor - Small (6) - 91172095 Large - 96068915 Receiver/dryer (2) - 96068488 Suction hose - 96068490 Discharge hose - 96068489 Suction hose - 91172091 Discharge hose - 91172085 1985-89 Spectrum and 1990-93 Storm (R) 1. Using the Service Manual, remove the following components in the order given: a. Condenser (Storm) or radiator grille (Spectrum) (to be reinstalled). b. Triple switch (Storm) or dual pressure switch (Spectrum) (to be reinstalled). c. Receiver/dryer. d. Evaporator to compressor (suction) pipe. e. Check valve from high side service valve (discard). f. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High side adapter fitting (see Step 3 of the retrofit procedure for detailed installation instructions). Low Side - Part of suction hose c. Evaporator to compressor (suction) pipe, and new 0-rings. d. Receiver/dryer and 0-rings. e. Triple switch or dual switch, and new 0-ring. f. Condenser or radiator grille. R-134a amount: 91 - 500 grams (1.10 lb) 92-93 - 600 grams (1.32 lb) PAG oil amount: 150 cc (4.50 oz) Parts Required: Receiver/dryer: 85-89 - 97104795 90-91 - 97104797 92-93 - 97104798 Adapter, High Side: Page 7240 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 3824 In some cases, the customer may not comment about a vibration but it is important to test drive the vehicle while using the electronic vibration analysis tool in an attempt to locate the cause of the torsional vibration. Refer to the Vibration Diagnosis and Correction sub-section of the appropriate Service Manual for more details on diagnosing and correcting vibrations. Disclaimer Page 4940 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 4952 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 7419 Symbol Identification Page 5744 - make sure parts positioning is correct (Figure 3). b. Install the link bolt (62) through the lower control arm hole (59) with the parts stacked properly (Figure 3). - Grommet (58) - Retainer (57) - Spacers (56) - Retainers (55) - Grommet (54) - Stabilizer (53) c. Attach the grommet (52), retainer (51) and nut (50) on the link bolt (62) (Figure 3) and tighten nut until the nut meets the end of the bolt threads (62) (Figure 3). 6. Install shock absorber (36) (Figure 2). a. Install retainer (35) and grommet (34) on the stem (33) (Figure 2). - Fully extend the stem (33). b. Install shock absorber (36) up through the lower control arm (40) and the spring (37). - Insert the stem (33) end through the hole in the upper control arm frame bracket (42) (Figure 2) c. Install the grommet (32), retainer (31), and the nut (30) on to the stem (33) (Figure 2). Tighten: Tighten bolt (38) to 27 N-m (20 lbs.ft.). SERVICE PARTS INFORMATION: Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Locations Typical Distributor Components Page 5072 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 7635 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 5262 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 6105 - Compressor hose assembly to 41 Nm (30 ft. lb.). 6. Electrical connectors, as necessary. 7. Refrigerant to the system. - Check the system for leaks. Page 2045 21. Timing chain, camshaft sprocket, and balance shaft drive gear. 22. Balance shaft driven gear. 23. Balance shaft retainer. 24. Intake manifold, as outlined in this section. 25. Lifter retainer. 26. Balance shaft and front bearing using a soft faced hammer. Engine, A/T - Shift/Driveability Concerns/MIL ON Continuously Variable Transmission/Transaxle: All Technical Service Bulletins Engine, A/T Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 7770 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Page 8314 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 8399 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 8244 Headlamp Switch: Service and Repair 1. Disconnect battery ground cable. 2. Remove headlamp switch trim plate and switch assembly attaching screws. 3. Disconnect electrical connectors from headlamp switch, then remove switch assembly from dash panel. 4. Reverse procedure to install. Page 7339 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Electrical Specifications Throttle Position Sensor: Electrical Specifications The throttle position sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Page 6418 Technical Service Bulletin # 431207E Date: 970101 A/C - Retrofitting R-12 to R-134a File In Section: 1 - HVAC Bulletin No.: 43-12-07E Date: January, 1997 INFORMATION Subject: Guidelines for Retrofitting R-12 Vehicles to R-134a Models: 1984-94 Passenger Cars and Trucks (See List Below) This bulletin is being revised with the following changes: 1. Addition of all remaining GM vehicles, as listed. 2. Format rearranged for easier use. Please discard Corporate Bulletin Number 43-12-07D (Section 1 - HVAC). Car/Truck Platform Coverage Starts: 1984 - A, B, D, E, F, J, K, P, Y Carlines 1985 - C, M, N, R, S Carlines 1986 - H Carline 1987 - L, V (Allante) Car lines; M/L, G, R/V, S/T, P Truck lines 1988 - T (LeMans), E (Reatta), W Car lines; C/k, MED. Duty Truck lines 1989 - Tracker 1990 - U Van Vehicles Not Covered: T (Chevette and T1000), G RWD, C RWD, and X Car If a vehicle is not covered in the list above, GM's recommendation is that the vehicle continue to be serviced with R-12. This bulletin outlines the detailed retrofit procedures, as well as providing background information on many components and procedures. It is important to follow the bulletin, since each car and truck line has unique parts and procedures. However, the basic procedure is simple, and will become easier as you complete more retrofits. A/T - Click or Whine in Third or Fourth Gear Clutch: Customer Interest A/T - Click or Whine in Third or Fourth Gear Number: 93-228-7A Section: 7A Date: JUNE 1993 Corporate Bulletin No.: 277121R ASE No.: A2 Subject: CLICK/WHINE IN THIRD/FOURTH GEAR Model and Year: 1988-93 CAPRICE, CAMARO AND CORVETTE 1988-93 C/K, RN, S/T, M AND G TRUCKS 1990-93 L VAN THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-157-7A, DATED APRIL 1992. THE 1993 MODEL YEAR HAS BEEN ADDED, AS WELL AS A NOTE IN THE CORRECTION SECTION. ALSO THE SERVICE PARTS INFORMATION HAS BEEN CHANGED. ALL COPIES OF 92-157-7A SHOULD BE DISCARDED. CONDITION: Some 1988-93 vehicles with HYDRA-MATIC 4L60 or 4L60-E transmissions built before November 19, 1992 (Julian Date 324) may exhibit a clicking or whining noise in third and fourth gear. A customer may also describe it as a ticking or rattle noise. CAUSE: The clicking noise is caused by transmission fluid passing over the friction plates of the low and reverse clutch. The fluid causes them to vibrate when the low and reverse clutch is not applied (third and fourth gear). CORRECTION: Install five new fiber plates in the low and reverse clutch. The new plates have a non-groove configuration. NOTE: All HYDRA-MATIC 4L60 and 4L60-E transmissions built on or after November 19,1992 (Julian Date 324) have been assembled with the new low and reverse clutch fiber plates. SERVICE PARTS INFORMATION: Parts are expected to be available on 6/07/93. Page 856 A wheel alignment will generally NOT correct vehicles that follow the road crown since this is within "Normal Operation." Mileage Policy The following mileage policy applies for E2020 and E2000 labor operations: Note Wheel Alignment is NOT covered under the New Vehicle Limited Warranty for Express and Savana Cutaway vehicles as these vehicles require Upfitters to set the wheel alignment after completing the vehicles. - 0-800 km (0-500 mi): E2000/E2020 claims ONLY allowed with Call Center Authorization. Due to the tie down during shipping, the vehicle's suspension requires some time to reach normal operating position. For this reason, new vehicles are generally NOT to be aligned until they have accumulated at least 800 km (500 mi). A field product report should accompany any claim within this mileage range. - 801-12,000 km (501-7,500 mi): - If a vehicle came from the factory with incorrect alignment settings, any resulting off-angle steering wheel, lead/pull characteristics or the rare occurrence of excessive tire wear would be apparent early in the life of the vehicle. The following policy applies: - Vehicles 100% Factory Set/Measured for Caster/Camber/Toe - Escalade/ESV/EXT, Tahoe/Suburban, Yukon/XL/Denali, Silverado/Sierra, Express/Savana, Corvette and Colorado/Canyon: E2000/E2020 Claims: Call Center Authorization Required - All Vehicles NOT 100% Factory Set/Measured for Caster/Camber/Toe as noted above: E2000/E2020 Claims: Dealer Service Manager Authorization Required - 12,001 km and beyond (7,501 miles and beyond): During this period, customers are responsible for the wheel alignment expense or dealers may provide on a case-by case basis a one-time customer enthusiasm claim up to 16,000 km (10,000 mi). In the event that a defective component required the use of the subject labor operations, the identified defective component labor operation will include the appropriate labor time for a wheel alignment as an add condition to the component repair. Important Only one wheel alignment labor operation claim (E2000 or E2020) may be used per VIN. Warranty Documentation Requirements When a wheel alignment service has been deemed necessary, the following items will need to be clearly documented on/with the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 1. Document the customer concern in as much detail as possible on the repair order and in the warranty administration system. Preferred examples: - Steering wheel is off angle in the counterclockwise direction by approximately x degrees or clocking position. - Vehicle lead/pulls to the right at approximately x-y mph. Vehicle will climb the road crown. Severe, Moderate or Slight. - RF and LF tires are wearing on the outside shoulders with severe feathering. Important In the event of a lead/pull or steering wheel angle concern, please note the direction of lead/pull (left or right) or direction of steering wheel angle (clockwise or counterclockwise) on the repair order and within the warranty claim verbatim. Important In the event of a tire wear concern, please note the position on the vehicle and where the wear is occurring on the tire; i.e., the RF tire is wearing on the inside shoulder. 2. Document the technician's findings on cause and correction of the issue. Examples: - Reset LF toe from 0.45 degrees to 0.10 degrees and RF toe from -0.25 degrees to 0.10 degrees to correct the steering wheel angle from 5 degrees counterclockwise to 0 degrees. - Reset LF camber from 0.25 degrees to -0.05 degrees to correct the cross-camber condition of +0.30 degrees to 0.00 degrees on the vehicle. - Front Sum toe was found to be 0.50 degrees, reset to 0.20 degrees. 3. Print-out the "Before" and "After" wheel alignment measurements/settings and attach them to the Repair Order or if print-out capability is not Page 7513 Cruise Control Switch: Locations Cruise Control Components, Near Steering Column. Part Of Multi-Function Lever Page 6200 Bearing Staked In Place Noisy bearing operation and reduced bearing life may result if outer bearing race is deformed while staking, The stake metal should not contact the outer race of the bearing. Stake three places 120 degrees apart. Installing Pulley Rotor And Bearing Assembly 5. With the compressor mounted to the J 33026 holding fixture, position the rotor and bearing assembly on the front head. 6. Position the J 33017 pulley, rotor and bearing installer and J 33023-A puller pilot directly over the inner race of the bearing. 7. Position puller crossbar J 8433-1 on the puller pilot J 33023-A and assemble the two J 33026-2 through bolts and washers through the puller bar slots and thread them into the J 33026 holding fixture. The thread of the through bolts should engage the full thickness of the holding fixture. 8. Tighten the center screw in the J 8433-1 puller crossbar to force the pulley rotor and bearing assembly onto the compressor front head. Should the J 33017 pulley rotor and bearing installer slip off direct in-line contact with the inner race of the bearing, loosen the J 8433-1 center forcing screw and realign the installer and pilot so that the J 33017 installer will properly clear the front head. 9. Install rotor and bearing assembly retainer ring, using snap ring pliers J 6083. 10. Reinstall clutch plate and hub assembly. Page 7725 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 6060 Vacuum Control Harness-Dash VACUUM SYSTEM Ports on rotary vacuum valves are illustrated to provide simplicity in following vacuum schematic lines but are numbered in consecutive order on the actual valve (see accompanying figures). Start the engine and allow it to idle. Move the selector lever to each position and refer to the vacuum diagrams and operational charts for airflow, air door functioning and vacuum circuits. If air flow is not out of the proper outlet at each selector lever position do the following: Inspect 1. The hose connections at the vacuum actuators, control head valve and vacuum tank. 2. The vacuum source circuit: - Install a vacuum tee and gage (with restrictor) at the vacuum tank outlet. Idle the engine and read the vacuum (a normal vacuum is equivalent to manifold vacuum) at all selector lever positions. - Vacuum less than normal at all positions. Remove the tee and connect the vacuum gage line to the tank-read the vacuum. If still low, then the problem lies in the feed circuit, the feed circuit to the tank or in the tank itself. If vacuum is now normal, then the problem lies downstream. - Vacuum less than normal at some positions. If vacuum was low at one or several of the selector lever positions, a leak is indicated in these circuits. - Vacuum normal at all positions. If vacuum was normal and even at all positions, then the malfunction may be caused by improperly connected or plugged lines or a malfunctioning vacuum valve or valves. 3. Specific vacuum circuit check: - Place the selector lever in the malfunctioning position and check for vacuum at the pertinent vacuum actuators. - If vacuum exists at the actuator but the door does not move, then the actuator is defective or the door is mechanically bound. Page 3218 Disclaimer Page 1200 Make sure the vehicle compressor is engaged. Turn the cart on and start the recovery cycle. OPEN ONLY THE HIGH SIDE VALVE ON THE GAUGE SET. The vehicle system should eventually shut the compressor off. If the low side pressure drops below 15 psi, and the compressor does not turn off, turn it off now (go to "VENT" or "ECON" mode), but leave the engine running and the blower on "high". c. After the recovery cart shuts off the first time, wait 5 minutes. If the pressure on either the high or the low side rises above 0 psi, restart the recovery process. After the second shutoff, wait 2 minutes. If the pressure again rises above 0 psi, restart, and after shutoff, again wait 2 minutes. The process can be stopped when the pressure does not rise above 0 psi after 2 minutes. The engine can be shut off at this time. d. Remove the R-12 reclaim hose and the gauge set from the vehicle. Any repairs needed should be done at this time. If any components other than the compressor are replaced, they should be installed dry, and no extra oil should be added. 3. Install the Service Port Conversion Fittings Important: For GEO vehicles, skip to Step 4. Fitting installation is covered in that step. For vehicles that require a HPCOS, see Step 4. Some of these vehicles use a specific combination fitting to mount the HPCOS, which includes the high side service port fitting and the HPCOS port. The low side fitting is installed as detailed below. See "Platform Details" for further information. Important: A new tool kit, P/N J 39500-250, has been released. This kit contains the following items: ^ J 39500-71 Oil Injection Bottle Conversion Kit (includes 3 12 oz bottles, an extender tube, caps, and fittings) ^ J 39500-275 Tool kit, including the following: (See Figure 2) - J 34611-A Double ended valve core remover - J 25498-A High side adapter fitting - J 38702 Deep valve core adapter fitting Page 139 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Brake Spring Removal and Installation Brake Shoe: Fundamentals and Basics Brake Spring Removal and Installation HOLD-DOWN SPRINGS Purpose Hold-down springs hold the shoes/linings against the backing-plate. The springs provide a flexible grip so that the shoes/linings will still be able to slide back and forth across the surface of the backing-plate. Tools Needed Specialized brake spring tool or - Pliers / needle nose locking pliers - Duct Tape (optional) Removal The hold-down spring must first be compressed so that the tip of the retaining pin is cleared of the spring. - The spring is then rotated so that the slot in top of the spring lines up with the tip of the retaining pin. NOTE: Be sure to hold the retaining pin from the rear of the backing-plate to prevent the pin from rotating with the spring. - The hold-down spring can then be released and the pin should slide through the slot in the top of the spring. - A specialized brake spring tool makes the job very simple. The tool firmly grips the surface of the hold-down spring while providing a clear view of the pin/slot relationship. Clutch Pedal - Pop or Scrape Noise When Depressed Clutch Pedal Assembly: All Technical Service Bulletins Clutch Pedal - Pop or Scrape Noise When Depressed File In Section: 7 - Transmission Bulletin No.: 46-73-03 Date: October, 1994 Subject: Clutch Pedal Return Spring Fractured (Remove Spring) Models: 1988-94 Chevrolet and GMC Truck C/K, S/T Models with Manual Transmission Condition Some owners may comment that they hear a pop or scrape noise, or feel a catch as they depress the clutch pedal. They may also comment that the clutch pedal return spring is fractured. This spring is located at the clutch pedal pivot. Cause Spring fatigue resulting in short service life. Correction Remove the clutch pedal return spring and DO NOT replace it. Refer to the appropriate Service Manual Section 7C - Clutch, Clutch Pedal Replacement for the correct procedure. Testing has shown that this spring is not needed for proper clutch pedal return or clutch pedal feel. This spring was eliminated in production as follows: ^ C/K all models, mid-1994 model year ^ S/T pickups, mid-1994 model year ^ S/T utilities, start of production 1995 model year Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time K0100 Spring, Clutch Use Published Labor Pedal Return Operation Time Page 6100 Push-On Fan-Removal Procedure INSTALL OR CONNECT 1. Press fan onto shaft. - Grasp fan by dome and apply hand pressure to fan dome, insert fan on motor shaft until slightly seated on shaft. - Place fan and motor on a combination of 10mm x 3/8" drive socket and 1 1/2 x 3/8 reducer (see accompanying figure). - While steadying the fan and motor, apply steady force to rear of motor shaft using a drill press or small arbor press and pin. Adjust - Fan cage, using spacers, to a clearance of 5.5 mm (0.22 inches) to motor mount plate. 2. Blower motor and fan assembly. - Check circuit operation. Page 4751 Brake Caliper: Service and Repair Installation For additional information see Installation Notes. See: Fundamentals and Basics Retracting Piston 1. Retract piston in caliper bore and position caliper over disc, lining up holes in caliper with holes in mounting bracket. If brake hose was not disconnected during removal, be sure not to kink it during installation. Caliper Mounting Bolts 2. Start mounting bolts through sleeves in inboard caliper ears and the mounting bracket, making sure ends of bolts pass under ears on inboard pad. NOTICE: If the caliper was removed for service, make sure it is installed on the correct knuckle. The caliper bleed screw should be positioned on top of caliper when assembled on vehicle. 3. Push mounting bolts through to engage holes in the outboard ears. Then thread mounting bolts into bracket. 4. Torque mounting bolts to 50 Nm (37 ft lb). Page 7624 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 3727 PROM - Programmable Read Only Memory: Application and ID Reading Technical Service Bulletins Always read any Technical Service Bulletins (TSB's) referenced before replacing a PROM. Service bulletins list parts that must be installed when a PROM is changed, and provide information on trouble codes, troubleshooting and driveability problems for which the PROM was released. To find applicable TSB's: Complete TSB Listing 1. Hold down right mouse button and select "Vehicle" in the "Pull Right Menu". 2. Select the TSB ICON. 3. Select "All Technical Service Bulletins by Number, Date, and Title". 4. Select "Sort by Number", "Sort by Date", or "Sort by Title". 5. Scroll up or down to find the desired TSB. PROM TSB Listing Only 1. Hold down right mouse button and select "Technical Service Bulletins" in the "Pull Right Menu". 2. Select "All Technical Service Bulletins for PROM - Programmable Read Only Memory". 3. Select "Sort by Number", "Sort by Date", or "Sort by Title". 4. Scroll up or down to find the desired TSB. Page 2087 Disclaimer Page 6369 Retrofit Requirements The customer should be reminded that there is NO requirement in the U.S. to retrofit any vehicle produced with R-12. Vehicles built with R-12 can be serviced with R-12 as long as it is available (except in certain Canadian Provinces). GM has taken steps to extend the supply of R-12 and recommends that all R-12 vehicles continue to be serviced with R-12 as long as it is available. Training Video Before doing a retrofit the first time, it is recommended that you view the Certified Plus Training Video, Program number 51010.15, "R-134a Retrofit for GM Cars and Trucks". Table of Contents A. Retrofit Procedure 1. Inspect Condition of Vehicle 2. Recover the R-12 (new method) 3. Install the service port conversion fittings 4. Install any additional parts needed 5. Evacuate and recharge with new PAG or V5 retrofit oil and R-134a 6. Install the retrofit label Platform Details Compressor Replacement Chart B. General Information 1. Performance 2. Leakage 3. Desiccant 4. Improved Cooling Performance 5. PAG or V5 Oil Compatibility 6. Refrigerant Oil Level Coil Spring Replace Suspension Spring ( Coil / Leaf ): Service and Repair Coil Spring Replace Fig. 1 Removing Spring With Adapter J-23028. 4 X 2 Models 4 X 2 MODELS 1. Raise and support vehicle. 2. Remove the two shock absorber screws and push shock up through control arm and into spring. 3. Support vehicle so that control arms hang free. 4. Place coil spring remover and installer tool No. J-23028, or equivalent, into position cradling the inner bushings, Fig. 1. Tool should be secured to a jack. 5. Remove stabilizer to lower control arm attachment. 6. Raise the jack to remove tension on lower control arm pivot bolts, then install a chain around spring and through control arm and remove the nuts and bolts. 7. Lower control arm by slowly lowering jack. 8. With all pressure removed from spring, remove safety chain and spring. Do not apply force to lower control arm and ball joint to remove spring. Proper maneuvering of spring will allow for easy removal. 9. Reverse procedure to install, noting the following: a. Ensure coil spring is installed with flat coiled end with gripper notch on top and the lower coil covering all or part of one drain hole in lower control arm and with other hole exposed. b. Install both lower control arm bolts from front to rear to ensure adequate steering linkage clearance. c. Torque stabilizer link nuts to specification, lower vehicle and torque lower control arm bolt nuts to specification, after suspension had been weighted. Page 8526 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 5030 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 486 - Install the blower switch knob. 2. Control cables (60 and 65). 3. Electrical connection (82). 4. Control assembly (63). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 5. Screws (64). - Check circuit operation. Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ROCKER ARM NUT TORQUE Valve Rocker Arm Nuts ....................................................................................................................... ................................................ 27 Nm (20 lb. ft.). Page 4343 Axle Shaft Assembly: Description and Operation Chevrolet Salisbury Semi-Floating Salisbury type semi-floating rear axle Semi-floating Rear Axle W/9 1/2 Inch Ring Gear In these axles, the axle housing and differential carrier are cast into an integral assembly. The drive pinion assembly is mounted in two opposed tapered roller bearings. The pinion bearings are preloaded by a spacer behind the front bearing. The pinion is positioned by a washer between the head of the pinion and the rear bearing. The differential is supported in the carrier by two tapered roller side bearings. These bearings are preloaded by spacers located between the bearings and carrier housing. The differential assembly is positioned for proper ring gear and pinion backlash by varying these spacers. The differential case houses two side gears in mesh with two pinions mounted on a pinion shaft which is held in place by a lock pin. The side gears and pinions are backed by Page 7362 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 8607 Power Window Motor: Service and Repair Door Inner Panel Water Deflector Replacement Front Inner Panel Water Deflector NOTE: Waterproof deflectors are used to seal the door inner panel, and to prevent water from entering into the body. The deflector is secured by a strip of adhesive between the deflector and the door, as well as waterproof sealing tape. REMOVE OR DISCONNECT 1. Door trim panel. 2. Plastic fasteners (when used). 3. Armrest bracket. 4. Water deflector. ^ Pull the waterproof sealing tape from the deflector. ^ Break the bond between the sealer and the door with a flat-bladed tool. INSTALL OR CONNECT 1. Water deflector strip caulking as a sealant between the deflector and the door, If needed. 2. Plastic fasteners (when used). 3. Waterproof tape. 4. Armrest bracket. 5. Door trim panel. Page 7631 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Locations Horn Relay Installation Page 6260 Compressor Shaft Seal: Service and Repair With SD-709 Compressor Compressor Components Always replace the shaft seal assembly if it is disassembled. Never reuse any of the old parts. To service the shaft seal without disassembling the clutch, perform steps 1 and 2 under "Clutch" and then proceed as follows. Remove or Disconnect Tools Required: J 4245 internal Snap Ring Pliers J 9553-01 Ring Remover J 38468 Shaft Seal Remover and Installer J 38479 Seal Seat Remover and Installer 1. Clutch shims (3) using J 9553-01 and a small screwdriver 2. Felt ring metal retainer (25). Clutch Pedal - Pop or Scrape Noise When Depressed Clutch Pedal Assembly: All Technical Service Bulletins Clutch Pedal - Pop or Scrape Noise When Depressed File In Section: 7 - Transmission Bulletin No.: 46-73-03 Date: October, 1994 Subject: Clutch Pedal Return Spring Fractured (Remove Spring) Models: 1988-94 Chevrolet and GMC Truck C/K, S/T Models with Manual Transmission Condition Some owners may comment that they hear a pop or scrape noise, or feel a catch as they depress the clutch pedal. They may also comment that the clutch pedal return spring is fractured. This spring is located at the clutch pedal pivot. Cause Spring fatigue resulting in short service life. Correction Remove the clutch pedal return spring and DO NOT replace it. Refer to the appropriate Service Manual Section 7C - Clutch, Clutch Pedal Replacement for the correct procedure. Testing has shown that this spring is not needed for proper clutch pedal return or clutch pedal feel. This spring was eliminated in production as follows: ^ C/K all models, mid-1994 model year ^ S/T pickups, mid-1994 model year ^ S/T utilities, start of production 1995 model year Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time K0100 Spring, Clutch Use Published Labor Pedal Return Operation Time Page 1630 Rocker Arm Assembly: Adjustments VALVE ADJUSTMENT The VIN W engine does NOT have adjustable valve lash. When servicing the valve train requires removing and re-installing the rocker arms, tighten the rocker arm nuts to 27 Nm (20 ft. lbs.). A/T - Vibration/Rattle, Torque Converter Clutch Applied Torque Converter: All Technical Service Bulletins A/T - Vibration/Rattle, Torque Converter Clutch Applied Number: 93-38-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277145 ASE No.: A2 Subject: DRIVELINE VIBRATION AND/OR GEAR RATTLE WITH TORQUE CONVERTER CLUTCH (TCC) APPLIED Model and Year: 1992-93 S/T TRUCKS WITH 4.3L (L35) ENGINE AND 4L60 OR 4L60-E AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1992 HYDRA-MATIC 4L60 (MD8) 1993 HYDRA-MATIC 4L60-E (M30) TRANSMISSION MODELS: 2TAM, 2TBM, 3TAD, 3TBD SUBJECT: Driveline Vibration and/or Gear Rattle with TCC Applied VEHICLE APPLICATIONS: S/T Trucks with L35 Condition: Some 1992-1993 S and T trucks equipped with 4.3 liter (L35) engine and the HYDRA-MATIC 4L60 or 4L60-E transmission built before Julian Date 223 (August 10, 1992) may exhibit a rattle or driveline vibration with the torque converter clutch (TCC) applied at low engine speeds (1000-2000 RPM). Cause: The rattle or driveline vibration may be due to the stiffness of the spring rate of the damper springs in the torque converter. Correction: Install a new torque converter assembly which corrects the rattle in the 1000-2000 RPM operating range. Diagnosis Information: The rattle or driveline vibration condition only occurs in fourth gear with TCC applied. Use the following procedure to determine if the vehicle has this condition: 1. Accelerate the vehicle to achieve fourth gear and confirm that TCC is applied. 2. Maintain low engine speed (1000-2000 RPM) then crowd the throttle to above 25 percent TPS to induce the rattle or drive line vibration. NOTE: Excessive throttle input will disengage the TCC. Applying the brake will also disengage the TCC. Service Parts Information: Part Name Part Number Torque Converter Assembly (DBAF) 8688904 Parts are currently available from GMSPO. Page 1329 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7056 Time Allowance: See Chants NOTE: The time allowances provided on the chart include the hardware removal and installation (as indicated by the list guidelines), the masking and unmasking of the vehicle, stripping of the surface (as indicated by the guidelines), the refinish (and colorcoat when required), mix time for primer/ paint (and clearcoat when required), finesse/polish where required, washing and preparing the vehicle for delivery. OPERATION DESCRIPTION: PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER, REFINISH ENTIRE BODY ABOVE BODY SIDE MOLDINGS. PAINT TERM DEFINITIONS Following are definitions of paint repair terms used in this bulletin: Basecoat: A color topcoat that requires a clear topcoat over it. Break line: A natural dividing line on Page 8583 Vanity Mirrors And Map lights Page 7334 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 6003 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Page 4596 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 8204 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 6372 - J 41265 Thread cleaning wire brush - J 41266 Low side port thread restorer - J 41267 High side port thread restorer - J 39037 High side octagon socket - J 41256 Low side octagon socket New low profile, quick connect couplers, J 39500-20A (High side), and J 39500-24A (Low side), have been released as essential tools, to attach to the ACR4 (see Figure 3). These are much smaller couplers than the existing ones, and will allow attachment to the port fittings in much tighter quarters. Accelerator and Cable Replacement Throttle Cable/Linkage: Service and Repair Accelerator and Cable Replacement Accelerator Pedal Assembly ACCELERATOR PEDAL When performing service on the accelerator pedal, observe the following: The mounting surface between the support and dash panel must be free of insulation. The carpet and padding in the pedal and tunnel area must be positioned to lay flat and be free of wrinkles and bunches. - Slip the accelerator control cable through the slot in the rod and then install the retainer in the rod, makeing sure it is seated. Use care when pressing the retainer into the hole in the rod to ensure that the cable is not kinked or damaged in any way. - After securing all components of the accelerator linkage, the linkage must operate freely without binding between full closed throttle and full wide open throttle. - Wires, hoses, cables or other obstructions must not be placed within 13 mm (1/2 inch) of the cable or the rod at any point in their travel. Accelerator Cable CMFI Page 5544 A wheel alignment will generally NOT correct vehicles that follow the road crown since this is within "Normal Operation." Mileage Policy The following mileage policy applies for E2020 and E2000 labor operations: Note Wheel Alignment is NOT covered under the New Vehicle Limited Warranty for Express and Savana Cutaway vehicles as these vehicles require Upfitters to set the wheel alignment after completing the vehicles. - 0-800 km (0-500 mi): E2000/E2020 claims ONLY allowed with Call Center Authorization. Due to the tie down during shipping, the vehicle's suspension requires some time to reach normal operating position. For this reason, new vehicles are generally NOT to be aligned until they have accumulated at least 800 km (500 mi). A field product report should accompany any claim within this mileage range. - 801-12,000 km (501-7,500 mi): - If a vehicle came from the factory with incorrect alignment settings, any resulting off-angle steering wheel, lead/pull characteristics or the rare occurrence of excessive tire wear would be apparent early in the life of the vehicle. The following policy applies: - Vehicles 100% Factory Set/Measured for Caster/Camber/Toe - Escalade/ESV/EXT, Tahoe/Suburban, Yukon/XL/Denali, Silverado/Sierra, Express/Savana, Corvette and Colorado/Canyon: E2000/E2020 Claims: Call Center Authorization Required - All Vehicles NOT 100% Factory Set/Measured for Caster/Camber/Toe as noted above: E2000/E2020 Claims: Dealer Service Manager Authorization Required - 12,001 km and beyond (7,501 miles and beyond): During this period, customers are responsible for the wheel alignment expense or dealers may provide on a case-by case basis a one-time customer enthusiasm claim up to 16,000 km (10,000 mi). In the event that a defective component required the use of the subject labor operations, the identified defective component labor operation will include the appropriate labor time for a wheel alignment as an add condition to the component repair. Important Only one wheel alignment labor operation claim (E2000 or E2020) may be used per VIN. Warranty Documentation Requirements When a wheel alignment service has been deemed necessary, the following items will need to be clearly documented on/with the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 1. Document the customer concern in as much detail as possible on the repair order and in the warranty administration system. Preferred examples: - Steering wheel is off angle in the counterclockwise direction by approximately x degrees or clocking position. - Vehicle lead/pulls to the right at approximately x-y mph. Vehicle will climb the road crown. Severe, Moderate or Slight. - RF and LF tires are wearing on the outside shoulders with severe feathering. Important In the event of a lead/pull or steering wheel angle concern, please note the direction of lead/pull (left or right) or direction of steering wheel angle (clockwise or counterclockwise) on the repair order and within the warranty claim verbatim. Important In the event of a tire wear concern, please note the position on the vehicle and where the wear is occurring on the tire; i.e., the RF tire is wearing on the inside shoulder. 2. Document the technician's findings on cause and correction of the issue. Examples: - Reset LF toe from 0.45 degrees to 0.10 degrees and RF toe from -0.25 degrees to 0.10 degrees to correct the steering wheel angle from 5 degrees counterclockwise to 0 degrees. - Reset LF camber from 0.25 degrees to -0.05 degrees to correct the cross-camber condition of +0.30 degrees to 0.00 degrees on the vehicle. - Front Sum toe was found to be 0.50 degrees, reset to 0.20 degrees. 3. Print-out the "Before" and "After" wheel alignment measurements/settings and attach them to the Repair Order or if print-out capability is not Page 6805 For vehicles repaired under the terms of this special coverage, submit a claim with the information shown. Customer Reimbursement All customer requests for reimbursement for previous repairs for the special coverage condition will be handled by the Customer Assistance Center, not by dealers. Disclaimer Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Gauge: All Technical Service Bulletins Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 7092 91 Dk. Argent 6270 C9124 45880 45880 34781 22223 GM-22223 94 Blue Red Metallic B/C 9088 B9018 42481 42481 4240 20051 GM-9088 96 Ultra Silver Metallic B/C 8867 B8795 36457 36547 4023 18112 GM-8867 97 Dk. Grey Metallic B/C 9658 B9127 44153 44153 4313 21024 GM-9658 B/C Basecoat/Clearcoat *M/L Van Only 1992 TRUCK INTERIOR COLORS Page 5520 Disclaimer Page 4364 shaft, use tool No. J-8853-01 or equivalent. Position chamfer on outer diameter of bearing retainer toward bearing. On models with limited slip, both axle shaft splines should be fully engaged before axle shaft is rotated to maintain spline alignment. Corporate REAR DRIVE AXLE Fig. 3 Pinion Shaft Lock Screw & Axle C-lock. GM Axle 1. Raise vehicle and support vehicle, then remove wheel and brake drum or rotor. 2. Drain lube from carrier and remove cover. 3. Remove differential pinion shaft lock screw and remove differential pinion shaft, Fig. 3. 4. Pull flange end of axle shaft toward center of vehicle and remove C-lock from button end of shaft, Fig. 3. 5. Remove axle shaft from housing, being careful not to damage seal. 6. Reverse procedure to install the axle shaft. A/T - Extension Seal Leaks Seals and Gaskets: Customer Interest A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Locations Malfunction Indicator Lamp: Locations Instrument cluster. Page 1041 1992 LB4 VIN Z For vehicles with "cold knock" only. For vehicles with "cold knock" having previously installed detonation field fix PROM - OR For vehicles with "cold knock" and detonation For 1991-93 model year L05 and L19, 1991 and 1993 LB4 engines, two actions have been found to show a high probability of success incuring short duration cold knock (Category A). General Motors suggests performing the following steps. NOTE: These steps are only applicable to short duration cold knock, and will not eliminate a knock occurring under load. Neither will these actions eliminate a knock lasting more than 10 seconds, nor a knock occurring in a hot or warm engine. Step 1: Install a check valve oil filter Original Filter Install PF35 AC PF1218 PF51 AC PF52 Step 2: Change the oil; use a synthetic oil meeting the API Service SG or SG/CE standard. NOTE: This action is only required once; conventional (non-synthetic) API Service SG or SG/CE oil may be reinstalled at the next oil change. If an LB4 (VIN Z 4.3L V6) or an L05 (VIN K 5.7L V8) continues to exhibit short duration cold knock after performing steps one and two and Page 3247 Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards The following gasoline brands meet the TOP TIER Detergent Gasoline Standards in all octane grades : Chevron Canada (markets in British Columbia and western Alberta) - Shell Canada (nationally) - Petro-Canada (nationally) - Sunoco-Canada (Ontario) - Esso-Canada (nationally) What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency and no metallic additives. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent recommendations of Canadian standards and does not contain metallic additives, which can damage vehicle emission control components. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began in the U.S. and Canada on May 3, 2004. Some fuel marketers have already joined and introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: BMW, General Motors, Honda, Toyota, Volkswagen and Audi. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. In the U.S., government regulations require that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In Canada, gasoline standards recommend adherence to U.S. detergency requirements but do not require it. In fact, many brands of gasoline in Canada do not contain any detergent additive. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required or recommended, and no metallic additives are allowed. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency and the intentional addition of metallic additives is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Clean engines help provide optimal fuel economy and engine performance, and also provide reduced emissions. Also, the use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Who should use TOP TIER Detergent Gasoline? All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. More information on TOP TIER Detergent Gasoline can be found at this website, http://www.toptiergas.com/. Page 757 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 83 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts 7 1/2 - 8 1/2 Inch Ring Gear Differential Clutch: Service and Repair 7 1/2 - 8 1/2 Inch Ring Gear Cam Gear Clutch Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 1. Remove retaining ring from end of cam gear, Fig. 8. 2. Remove discs and cam plate from gear, keeping all components in order. 3. Clean and inspect components, and replace any that are damaged, distorted or excessively worn. If cam gear must be replaced, refer to CAM GEAR SHIM SELECTION for shim selection procedures prior to case reassembly. 4. Position gear on flat surface with hub end up, and assemble cam plate onto gear with cam form down to mate with cam form on gear. 5. Assemble two eared discs, one splined disc and one wave washer on cam gear, starting with eared disc as shown in Fig. 8. 6. Alternately assemble three eared discs and two splined discs on cam gear hub, starting with eared discs. 7. Install retaining ring, ensuring that retainer is fully seated. Side Gear (RH) Clutch Page 6877 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Description Labor Op. Striker and/or Support - Replace (RH) B5820 Striker and/or Support - Replace (LH) B5821 Locations EGR Valve Position Sensor: Locations Engine Wiring, LH Side Page 1644 needle bearing of the balance shaft. 4. To eliminate the possibility of the rear needle bearing rattling, a production running change was made in early May 1992, to a different type bearing. The needle bearing was changed to a journal type sleeve bearing (much like a camshaft bearing). This type bearing requires pressure fed oil, therefore, an engine block casting change was made to allow an oil passage to be drilled from the vertical oil gallery coming from the oil filter to the rear balance shaft journal. 5. If the detonation type rattle noise is unacceptable to the customer, the engine must be replaced using an SPO Goodwrench engine assembly part number 12520408. Important: Dealers are to retain all parts replaced for inspection in accordance with GM Service Policy and Procedures section 1.7.4 - Disposition of Defective material. Important: Replaced engine blocks are NOT to be provided to engine rebuilders. They should be returned as per instructions shipped with the replacement engine. 6. MEM-CAL information: When replacing a 1992 needle bearing engine (only produced prior to the May 1992 VIN break-points) with a sleeve bearing engine, the MEM-CAL must be updated to the later 1992 version. See part number information below. These new MEM-CALs are required to change the ESC calibration for the sleeve bearing engine. Without the correct calibration MEM-CAL, the engine will detonate. 7. ESO (Electronic Spark Control) information: The sleeve bearing engine "sounds" different to the ESO system. To make the sleeve bearing engine operate properly the 1992 M and L van vehicles, the knock sensors and locations have been changed. The 1992 M/L motors require only one 3900 ohm knock sensor mounted in the transmission flange close to the distributor. Connect the knock sensor harness to the knock sensor in the transmission flange. The second knock sensor connector harness at the middle of the right cylinder head will not be used on the 1992 model year M and L vans with the sleeve bearing engines. To ensure the harness does not lie on the exhaust manifold and short out, tie the connector back onto the harness using a plastic tie strap. The S and T trucks will continue using both 8200 ohm knock sensors with the sleeve bearing engine. No modification to the existing harness is necessary. Sleeve Bearing Balance Shaft Knock Sensor Information VIN Breakpoints for Sleeve Bearing Engines Beginning with: Service and Repair Band Apply Servo: Service and Repair 1. Disconnect battery ground cable, then raise and support vehicle. 2. Install servo cover compressor tool No. J-29714, then remove 2-4 servo cover retaining ring using a small screwdriver. 3. Remove servo cover and O-ring using suitable tool. 4. Remove fourth gear apply piston and O-ring, then the second servo piston assembly. 5. Remove inner servo piston assembly oil seal and spring. 6. Reverse procedure to install. TCC Solenoid Rear Of Engine Page 8277 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Left Side Knock Sensor Engine Wiring, LH Side Page 158 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Fuels - Effect of Volatility on Driveability Fuel: All Technical Service Bulletins Fuels - Effect of Volatility on Driveability Number: 93-31-6C Section: 6C Date: OCT. 1992 Corporate Bulletin No.: 249128R ASE No.: A1, A8 Subject: EFFECT OF FUEL VOLATILITY ON DRIVEABILITY CONDITIONS Model and Year: ALL MODEL YEARS, ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-281-6C, DATED SEPT. 1992. THE 1993 MODEL YEAR HAS BEEN ADDED. ALL COPIES OF 92-281-6C SHOULD BE DISCARDED. Recent changes in EPA regulations have effectively lowered the maximum allowable fuel volatility. Volatility, which can be defined as a gasoline's ability to change from a liquid to a vapor, directly affects the amount of evaporative emissions produced by the fuel. Higher volatility means that more unburned hydrocarbons will be released into the atmosphere. Unfortunately, reducing fuel volatility can cause problems during cold engine operation when low temperatures impede the fuel's ability to vaporize and burn. Two terms are often used to describe volatility characteristics. These are: Distillation Curve A graph showing the relationship between temperature and the percentage of fuel evaporated. The fuel components that boil at relatively low temperatures (below about 90 degrees F) are known as the "light ends", and are essential for good cold engine performance. The "heavy ends", which begin to boil at about 300 degrees F, contain the most energy but are more difficult to burn. Laboratory analysis is usually required to determine the distillation curve of a gasoline sample. - Reid Vapor Pressure (RVP) RVP is the pressure (psi) that vaporized fuel exerts within a sealed container as it is heated to 100 degrees F. The higher the RVP the higher the fuel volatility. While RVP is readily tested in the field, fuels of the same RVP can have different distillation curves and cold driveability characteristics. Fuel volatility will vary depending on geographic location and time of year (fuel intended to be used in higher ambient conditions is formulated with less volatility). This can make cold driveability as big a problem during summer months as during the winter. There may be additional variation in the volatility characteristics of pump gasoline, caused by the differences in fuel manufacturers, blends and storage times. As EPA fuel volatility standards are lowered, variations between fuels (which may further reduce volatility) becomes a critical factor influencing cold engine performance. No matter how thoroughly the relationship between fuel quality and cold driveability is understood, eliminating fuel quality as an issue can be difficult, because: TOOLS WHICH TEST FUEL VOLATILITY MEASURE ONLY RVP, NOT THE DISTILLATION CURVE. The distillation curve has a greater effect on cold driveability than RVP. THE CUSTOMER MAY PERCEIVE RAISING THE FUEL QUALITY ISSUE AS AN ATTEMPT TO EVADE HIS PROBLEM. This may cause difficulty in getting accurate fuel usage information. WATER, AND OTHER TYPES OF FUEL CONTAMINATION, MAY CAUSE CONTINUED DRIVEABILITY COMPLAINTS. - The problem symptoms may remain even though the vehicle has been refueled several times with a quality gasoline. CUSTOMER CONCERNS CONDITION: Poor Cold Engine Operation, symptoms may include; hard start/extended crank, stalling, backfiring, hesitation and/or lack of power. POSSIBLE CAUSE: Low volatility fuel will not vaporize sufficiently to allow normal combustion. CORRECTION: Replace Fuel. DIAGNOSTIC PROCEDURE: 1. Perform basic system checks in section 6E of the service manual. 2. Check for service bulletins which relate to cold driveability issues specific to the problem vehicle. Testing and Inspection Fuel Pump Control Unit: Testing and Inspection PROCEDURE: - Disconnect fuel module - With test light and ignition "ON", probe connector terminal "C" to ground. Circuit is OK if light is "ON". There is an open if the light is "OFF". - Probe connector terminals "C" to "D" with test light. Circuit is OK if light is "ON". There is an open in the ground circuit if light is "OFF". - Ignition "OFF", probe connector terminals "A" to "D" with test light. Ignition "ON", test light should illuminate for two seconds. There is an open in the circuit if the light is "OFF". - Replace fuel module if there is no twenty second fuel pump operation. Page 4586 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Service and Repair Fuel Pressure Release: Service and Repair Fuel Supply System CMFI FUEL PRESSURE RELEASE PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure - Connect fuel pressure gauge to fuel pressure connection tap. Wrap a shop towel around fitting while connecting gauge to avoid spillage. - Install bleed hose into an approved container and open valve to bleed system pressure. Fuel connections are now safe for servicing. - Drain any fuel remaining in gauge into an approved container. Page 5426 Relay Box: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Wheels - Finish Damage During Off Car Balancing Wheels: All Technical Service Bulletins Wheels - Finish Damage During Off Car Balancing BULLETIN NUMBER: 93-3E-67 SECTION: 3E Wheels & Tires NUMBER: 3 CORPORATE REFERENCE NUMBER: 3935O2R DATE: June 1993 SUBJECT: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING MODELS: 1985-93 MODELS WITH ALUMINUM WHEELS Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car vehicle balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make Vehicle Speed Sensor (VSS) Module/Buffer Vehicle Speed Sensor Buffer (DRAC) Fuel Meter Body Assembly Throttle Body: Service and Repair Fuel Meter Body Assembly Fuel Meter Body Assembly REMOVE/DISCONNECT - Electrical connections to fuel injectors. (Squeeze plastic tabs and pull straight up.) - Fuel meter cover assembly, refer to FUEL METER COVER ASSEMBLY. - Fuel injectors, refer to FUEL INJECTOR ASSEMBLIES. - Fuel inlet and outlet lines. Discard O-rings. - Fuel inlet and outlet nuts and gaskets from fuel meter body assembly. Discard gaskets. NOTE Note locations of nuts, for proper reassembly later. Inlet nut has a larger passage than outlet nut. - Fuel meter body to throttle body attaching screw assemblies. - Fuel meter body assembly from throttle body assembly. - Throttle body to fuel meter body gasket and discard. INSTALL/CONNECT - New throttle body to fuel meter gasket. Match cut-out portions in gasket with openings in throttle body. - Fuel meter body assembly on throttle body assembly. - Fuel meter body-to-throttle body attaching screw assemblies, precoated with appropriate locking compound. Tighten screw assemblies to 4.0 Nm (35.0 lb-in). - Fuel inlet and outlet nuts with new gaskets to fuel body assembly. Tighten inlet nut to 40.0 Nm (30.0 lb-ft) and outlet nut to 29.0 Nm (21.0 lb-ft). - Fuel inlet and return lines and new O-rings. (Use back-up wrench to keep TBI nuts from turning. Tighten fuel lines to 27.0 Nm (20.0 lb-ft). - Injectors with new upper and lower O-rings in fuel meter body assembly. - Fuel meter cover gasket, fuel meter outlet gasket, and pressure regulator seal. - Fuel meter cover assembly. - Long and short fuel meter cover attaching screw assemblies, coated with appropriate compound. Tighten screw assemblies to 3.0 Nm (27.0 lb-in). - Electrical connectors to fuel injectors. INSPECT Locations Engine Wiring, LH Side Page 4876 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 5377 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 8272 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. A/T - 2004R/700R4 Oil Pump & Slide Service Fluid Pump: Technical Service Bulletins A/T - 2004R/700R4 Oil Pump & Slide Service SIL 86-27 (Nov) SUBJECT: 200 R4/700 4R SERVICE PROCEDURES FOR THE OIL PUMP ROTOR & SLIDE Beginning mid November, 1983, service parts became available to service the oil pump rotor and slide of the pump body assembly, on all THM 200-4R and 700-R4 transmissions. This service procedure on all THM 200-4R and 700-R4 transmissions must be followed to assure proper end clearance on the oil pump rotor and slide. SERVICE PROCEDURE: Note DO NOT attempt to service the oil pump rotor if either the pump body pocket or pump body cover surfaces are scored. Servicing of the oil pump rotor and slide should be performed ONLY if the selective pump rotor, or the slide show wear. 1. Disassembly of the oil pump: A. Disassemble the oil pump body assembly following procedures outlined in the service manual. Refer to Figure 1 for the THM 200-4R and Figure 2 for the THM 700-R4 transmission oil pump body assembly. 2. Selecting the pump rotor and slide: Page 6651 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Locations A/C And Heater Wiring Page 7034 Page 7850 Diagnostic Circuit Circuit Description The diagnostic circuit check is an organized approach to identifying a problem created by an electronic engine control system malfunction. It must be the starting point for any driveability complaint diagnosis, because it directs the service technician to the next logical step in diagnosing the complaint. Understanding the chart and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of good parts. Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. This step is a check for the proper operation of the "Service Engine Soon" light. The "SES" light should be "ON" steady. 2. No "SES" light at this point indicates that there is a problem with the "SES" light circuit or the control module control of that circuit. 3. This test checks the ability of the control module to control the "SES" light. With the diagnostic terminal grounded, the "SES" light should flash a Code 12 three times, followed by any trouble code stored in memory. A PROM error may result in the inability to flash Code 12. 4. Most of the diagnostic charts use a Tech 1 to aid diagnosis, therefore, serial data must be available. If a PROM error is present, the control module may have been able to flash Code 12 or 51, but not transmit serial data. 5. Although the control module is powered up, a "Cranks But Will Not Run" symptom could exist because of an control module or system problem. 6. This step will isolate if the customer complaint is a "SES" light or a driveability problem with no "SES" light. Refer to Computers and Control Systems for a list of valid codes. An invalid code may be the result of a faulty "Scan" tool, PROM or control module. See: Powertrain Management/Computers and Control Systems 7. Comparison of actual control system data with the typical valves is a quick check to determine if any parameter is not within limits. Keep in mind that a base engine problem (i.e., advanced cam timing) may substantially alter sensor values. 8. If the actual data is not within the typical values established, refer to Computers and Control Systems. See: Powertrain Management/Computers and Control Systems Page 278 Engine Compartment Components Front Of Engine Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 HP Engine STD Engine Page 4175 Clutch Start Switch: Service and Repair Fig. 3 Clutch Start Switch Installation 1. Remove lower I/P trim panel. 2. Remove clutch start switch electrical connector. 3. Remove clutch start switch from clutch pedal. 4. Reverse procedure to install, Fig. 3. Page 191 Engine Control Module: Service and Repair Engine Control Module (ECM) Replacement When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure. 1. Disconnect battery ground cable. 2. Remove right side kick panel, then disconnect two ECM electrical connectors. 3. Remove ECM mounting hardware. 4. Remove ECM from passenger compartment. 5. Reverse procedure to install. IP Dimmer Control - Proper Setting Dimmer Switch: Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Page 7351 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Coolant Temperature Switch Engine Wiring, LH Side Page 6677 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Diagram Information and Instructions Relay Box: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Description and Operation Heated Glass Element: Description and Operation Voltage to the Timer Relay is available at all times through the PWR ACC Circuit Breaker and the ORN/BLK (60) wire. Ground for the Timer Relay and the Rear Window Defogger Switch is provided through the BLK (150) wire and Ground G102. With the Ignition Switch in RUN or START, voltage is available to the Timer Relay and the Rear Window Defogger Switch through the IGN/GAU Fuse and the PNK/BLK (39) wire. Momentarily closing the Rear Defogger Switch to the ON position allows current from the PNK/BLK (39) wire to flow through the Switch and the LT BLU (292) wire to the Timer Relay. This signal operates the Solid-State circuitry in the Timer Relay. Current from the PNK/BLK (39) wire flows through the relay coil and the relay contacts close. Current from the ORN/BLK (60) wire flows through the relay contacts and the PPL/WHT (293) wire to the Rear Defogger Switch ON Indicator and to the Rear Defogger Grid and G425 through the BLK (150) wire. The ON Indicator in the Rear Defogger Switch is lit whenever the system is in operation. After about 10 minutes, the timer in the Timer Relay turns off, opening the relay contacts. Current flows to the Rear Defogger Grid stops. The Rear Defogger system can be turned off before the end of the 10-minute timing period by moving the Rear Defogger Switch to the OFF position. This sends a momentary ground signal to the Timer Relay through the LT BLU (292) wire. This signal turns off the timing circuit and opens the relay contacts. The Rear Defogger Switch is lit with the Light Switch in PARK or HEAD through the GRA (8) wire. Refer to the Instrument Panel Lamps for further information. Page 6736 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Page 7759 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Page 329 Clutch Switch: Locations Cruise Control Clutch Switch Brake Pedal Switches. On the Clutch Pedal Support bracket. Exhaust - Noise/Growl From Muffler Muffler: All Technical Service Bulletins Exhaust - Noise/Growl From Muffler Number: 92-108-6F Section: 6F Date: FEB. 1992 Corporate Bulletin No.: 166606 ASE No.: A1,A8 Subject: NOISE/GROWL FROM MUFFLER Model and Year: 1992 S/T 4-DOOR TRUCKS WITH 4.3L TBI ENGINE Some owners of 1992 S/T four door utility vehicles with a 4.3L TBI engine (VIN code Z) built between the VIN breakpoints listed below may experience loud or noisy mufflers. This is due to the muffler's tuning tube being built out of manufacturers specifications. To correct this condition, replacement of the muffler is required. VEHICLES INVOLVED: VIN From SOP 1992 to N2113412 SERVICE PROCEDURE: Removing Exhaust Parts CAUTION: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury Using a penetrating oil on the threads of U-bolts can assist in the removal of the exhaust components. Installing Exhaust Parts When installing a new muffler and tailpipe, on any model, check for proper alignment. Rattles and noise vibrations in the exhaust system are usually caused by a misalignment of parts. When aligning the system, leave all bolts or nuts loose until all parts are properly aligned, then tighten working from the front to rear. Exhaust system hangers, hanger brackets, and clamps which are damaged should be replaced to maintain exhaust system alignment. Refer to S/T Service Manual section 6F Exhaust System for additional information. SERVICE PARTS INFORMATION Part Number Description 15662525 Muffler 15662531 Pipe Assembly 15595048 Clamp Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L2584 Use applicable labor time guide for labor hours. Page 1852 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 3881 NOTE: In the overhaul repair kits for the HYDRA-MATIC 4L60 there are two (2) sets of 3rd and 4th clutch fiber plates. The two 3rd and 4th clutch fiber plates are calibration sensitive and interchanging the wrong plates may cause premature failure. The chart shows which models should use the plates labeled "2050" Figure 3. Page 1097 Fluid - A/T: Service and Repair Turbo Hydra-Matic 4L60 (700-R4) Checking & Adding Fluid Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface, engine idling in park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, If fluid level is too low, complete loss of drive may occur especially when cold, Which can cause transmission failure. Every 100,000 miles, the oil should be drained, the pan removed, the screen should be cleaned or replaced if applicable, and fresh fluid added. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or use as a tow vehicle, this maintenance should be performed every 15,000 miles. Changing Oil 1. Raise vehicle and position drain pan under transmission pan. 2. Remove front and side attaching bolts form the oil pan. 3. Loosen rear attaching bolts approximately four turns. 4. Carefully pry transmission pan loose and allow fluid to drain. 5. Remove rear attaching bolts, pan and pan gasket. 6. Drain remaining fluid from pan, then clean pan and gasket surfaces with solvent and dry with compressed air. 7. Remove transmission screen. Remove O-ring seal from intake pipe or case bore. 8. Replace screen if applicable, or thoroughly clean screen assembly with solvent and dry with compressed air. 9. Install O-ring on intake pipe, then install screen assembly. 10. Install gasket on pan, then install pan and torque attaching bolts to 12 ft. lbs. 11. Lower vehicle and add approximately 5 qts. of Dexron II or Dexron III type transmission fluid through filler tube. 12. Start engine and let run at idle, then with brakes applied move selector lever through each gear range. 13. Place transmission in Park position and check fluid level. A/C - Erratic HVAC Operation & Self Diagnostic Blinks Air Conditioning Indicator Lamp: Customer Interest A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Page 2245 Labor Operation: J3390 Use applicable labor time guide for labor hours. Page 399 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 460 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Key-In Warning Buzzer Audible Warning Device: Description and Operation Key-In Warning Buzzer Voltage is supplied at all times to the Audio Alarm Module through the STOP-HAZ Fuse and the ORN (140) wire. With the key in the Ignition Switch and the Ignition Switch in ACC, LOCK or OFF, the chime or buzzer will sound if the left door is open. With the door open, the LH Door Jamb Switch closes to ground. This provides a ground to the Audio Alarm Module through the TAN (158) wire, the Key-in Ignition Switch, and the LT GRN (80) wire. The chime or buzzer will sound as long as the door is open or the key is in the Ignition Switch. Page 6441 Technical Service Bulletin # 631209 Date: 960501 A/C - R12 or R134a Service Recommendations File In Section: 1 - HVAC Bulletin No.: 63-12-09 Date: May, 1996 INFORMATION Subject: Service Issues for Vehicles with R12 or R134a Air Conditioning Systems Models: 1988-96 Passenger Cars and Trucks R12 Service Recommendations As you know, production of R12 refrigerant ceased on December 31, 1995. Although R12 will no longer be manufactured, there is a reserve supply of R12 available. This reserve, along with strict A/C repair service adherence to proper refrigerant recycling procedures, should assure continued availability to meet consumers' needs. R12 can and should continue to be used to service vehicles built with R12 A/C systems as long as it is available. If R12 is no longer available or affordable, a system retrofit utilizing R134a is recommended. R134a IS THE ONLY SUBSTITUTE REFRIGERANT RECOMMENDED BY GM FOR USE IN GM VEHICLE A/C SYSTEMS, AND THEN ONLY AFTER FOLLOWING THE PROPER RETROFIT PROCEDURES FOR THE SPECIFIC MODEL. All new vehicle manufacturers have chosen R134a for retrofit. One of the key reasons is to protect both the service industry and consumers from the high costs that would result from purchasing equipment necessary to service multiple refrigerants. This position also reduces the threat of recycled refrigerant contamination. GM currently offers a simple, low cost R12 to R134a retrofit on many of its late model, front wheel drive passenger cars. Dealers should discuss this capability with owners of these specific models, listed in Retrofit Corporate Bulletin # 43-12-07D, whenever a repair to the A/C refrigerant system is required. Early retrofit of these specific models will aid in prolonging availability of the R12 supply and provide dealer service technicians the opportunity to become more familiar with the proper procedures for performing a retrofit. Remember - R12 and R134a refrigerant are not interchangeable! They cannot be mixed together. In fact, despite the claims of some refrigerant manufacturers, no proposed R12 refrigerant substitute can be added to, mixed with or used to "top off" an R12 system. Under provisions of law covering the service of refrigerants, mixing dissimilar refrigerant products during service is prohibited. To Summarize GM R12 Service Policy 1. Service R12 vehicles with good quality new or recycled R12 as long as it is available. 2. Purchase R12 from a reliable supplier. GMSPO has a supply of high quality R12 available. Dealers are requested to use only R12 supplied by GMSPO for warranty repairs. This high quality refrigerant will insure system performance and avoid the possibility of introducing contaminated material into the customer's A/C system. 3. Carefully test recovered R12 using the PureGuard monitor. On recovery equipment not protected by the PureGuard, always test the recovery cylinder prior to recharging a vehicle A/C system. 4. Discuss the R12 to R134a retrofit option with owners of GM vehicles listed in Retrofit Corporate Bulletin # 43-12-07D. Provide owner with a copy of the pamphlet "Converting Your Auto Air Conditioning System to Use the New Refrigerant". 5. Become familiar with retrofit procedures and exercise care in the handling of dissimilar refrigerants to prevent contamination. R134A Service Recommendations When servicing a previously retrofitted vehicle, there is concern that if all of the R12 is not completely removed prior to the retrofit procedure, it could contaminate your R134a equipment and recovery tank when a subsequent A/C repair is performed. Although the number of retrofits being performed today is minimal, the volume will increase as R12 prices rise. GM Service Technology Group is in the process of field testing a new R134a refrigerant purity tester similar to the PureGuard R12 refrigerant tester you now use. This new tool will mount to your ACR4 R134a Recovery Recycle and Recharge cart and sample all R134a refrigerant prior to recovery. It is expected that testing of this tool will be completed this year. This new tool, the Pureguard 2, will also test vehicles and your recycle tank for air contamination, which is threatening A/C system performance. High levels of air have been found in the recovery tanks on a number of R12 and R134a recovery carts. Air contamination is caused by improper recovery Page 2141 Spark Plug: Description and Operation Spark Plug Identification Chart IDENTIFICATION Resistor-type, tapered-seat spark plugs are used on all engines. No gasket is used on these tapered seat plugs. Refer to image for an explanation of letter coding on spark plugs. A dot before the spark plug code or the letter "C" after the number in the code indicates the spark plug has a copper core. CONSTRUCTION AND OPERATION Normal or average service is assumed to be a mixture of idling, slow speed, and high speed operation with some of each making up the daily total driving. Occasional or intermittent high-speed driving is essential to good spark plug performance as it provides increased and sustained combustion heat that burns away any excess deposits or carbon or oxides that may have accumulated from frequent idling or continual stop and go or slow speed driving. Spark plugs are protected by an insulating boot made of special heat-resistant material which covers the spark plug terminal and extends over a portion of the plug insulator. These boots prevent flash-over with resultant missing of the engine, even though a film is allowed to accumulate on the exposed portion of the plug porcelains. DO NOT mistake corona discharge for flash-over or a shorted insulator. Corona is a steady blue light appearing around the insulator, just above the shell crimp. It is the visible evidence of a high-tension field, and has no effect on ignition performance. Usually it can be detected only in the darkness. This discharge may repel dust particles, leaving a clear ring on the insulator just above the shell. This ring is sometimes mistakenly regarded as evidence that combustion gases have blown out between the shell and the insulator. SPARK PLUG SELECTION Spark plus must operate within a certain temperature range if they are to provide the performance and service life expected of them. The spark plug selected for an engine is based on the normal service for which the engine is designed. The spark plug may not perform satisfactorily under other-than-normal operating conditions. For almost-exclusively city driving, a spark plug 1 step higher in heat range might deliver a longer service life than the spark plug recommended for normal operation. Conversely, a spark plug rated 1 step colder will perform better for heavy loads or continual high-speed driving. There are three rules to follow when selecting spark plugs for an engine in good condition: - Select a plug with a specific heat range. - Should spark plug overheating occur, select a spark plug that is one heat range lower than the specified range. - If fouling is a problem, select a spark plug that is one step higher that the specified range. Page 5201 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Page 7911 Page 7112 panel(s) that can be used as a starting/ stopping point when making a repair. Clearcoat: A clear topcoat required to cover a color basecoat. DELAMINATION: Loss of adhesion between one coat of paint to succeeding coats or coatings. Ultraviolet DELAMINATION is between the E coat (ELPO) and color topcoat(s). ELPO: (Electrocoating or "E" coat): The process by which electrically charged primer is plated on conductive surfaces of an opposite charge. This process provides outstanding corrosion resistance. Guidecoat: A light coat (almost overspray) of color applied over primer surfacer prior to wetsanding to highlight any low spots. Insert Color: The secondary two-tone color between the break line and body side molding. Monocoat: A color topcoat that does not require a clearcoat. Primer: The coating applied to a properly prepared substrate (bare metal) to give adhesion, corrosion and chemical resistance. Primer Sealer: An undercoat that provides maximum adhesion. color coating and corrosion protection. Primer Surfacer: An undercoat used to fill imperfections, with primer qualities, that must be sanded. Refinish: The act of replacing a painted surface, usually undercoat and topcoat. Scuff Sand: A method of sanding a painted surface using a fine grit sandpaper to promote paint adhesion. Topcoat: A finish material over an undercoat material. Ultraviolet Light: The portion of the spectrum of light which can cause fading of paint. It is located below the visible part of the spectrum. V.O.C.: "Volatile Organic Compound" or "Volatile Organic Content" relates to certain emission requirements in specific areas of the country. Page 7224 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 4285 11. Hold flange with suitable tool and remove pinion shaft nut and flange. 12. Lubricate pinion shaft oil seal and cover outer edge of seal body with non-hardening sealing compound, then press seal against cover shoulder with suitable tool. 13. Install new gasket and bearing cover. 14. Press flange against forward bearing and install washer and pinion shaft nut, torquing nut to 240 ft. lbs. Page 738 Clutch Start Switch: Service and Repair Fig. 3 Clutch Start Switch Installation 1. Remove lower I/P trim panel. 2. Remove clutch start switch electrical connector. 3. Remove clutch start switch from clutch pedal. 4. Reverse procedure to install, Fig. 3. Page 4623 4. Open the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (figure 2). Page 6400 contact or return to the previous repair facility. Explain that environmental regulations prohibit repair facilities from discharging ozone depleting A/C refrigerants into the atmosphere. Explain that recovery of this unknown refrigerant could damage your service equipment. If the customer wishes to pursue repairs through your facility, it is recommended that the proper A/C service equipment be purchased. General Motors recommends the Kent-Moore J 41428 "Scavenger", an air operated refrigerant recovery station, be used to remove unknown refrigerants. The air operated feature reduces the hazard of recovering potentially flammable refrigerants. Dealers should evaluate the need to purchase the equipment based on the number of contaminated vehicles they encounter. As an alternative to the initial purchase of a recovery only station, dealers should check locally for A/C specialty shops which may have the equipment to service substitute or contaminated refrigerants. They may be able to provide contaminated refrigerant recovery service to the dealer. The GM Service Technology Group has tested a recovery procedure where a 15 or 30 pound DOT approved refillable tank is fully evacuated then connected to a vehicle A/C system to recover the charge. Testing has shown that even when the recovery tank is cooled down in dry ice, the procedure does not guarantee the entire charge will be recovered. Since EPA regulations require full recovery of ozone depleting substances, GM does not recommend this procedure. Contaminated Refrigerant Disposal Although A/C refrigerant testing and disposal have not been a service practice in the mobile A/C industry, It has been common in the stationary A/C service industry for many years. Listed at the end of this bulletin are companies that provide refrigerant disposal service for the stationary A/C industry. Please be advised that GM has not independently evaluated these companies and is not in any way endorsing or promoting the use of these companies. Each of these companies has expressed an interest in providing refrigerant disposal service to GM dealers. In working with the stationary A/C industry, these companies typically receive large volumes of different refrigerants that have been mixed together. Unfortunately, because the volume of material returned by the mobile A/C industry will be in much smaller quantities, the cost of handling will be greater. To arrange for return of the refrigerant, simply call the company nearest you using the phone number listed below. The company will advise you on billing and shipping procedures. Disposal cost will vary between $3.00 and $5.00 per pound plus freight and handling. Shipping charges will vary by distance and location. In general, a 7 to 10 day turn-around time on the tank can be expected. The tank can be shipped via common carrier. Documents that your refrigerant has been properly disposed of will be sent to you with the return of your tank. As an alternative, many dealerships already have contracts in place with a disposal company who manages their hazardous wastes. In these cases, the disposal service may agree to handle containers of mixed refrigerants. Initially, the local disposal companies may be surprised by this inquiry. They may want to evaluate how much material will be collected before deciding whether to provide this service. As we move forward with the practice of testing R12 refrigerant, it will take time for all the questions to be answered. STG will provide additional information as soon as it is available. Understanding The PureGuard The PureGuard is a highly sensitive instrument capable of detecting R12 with 3% or less cross-contamination with other refrigerants. Any refrigerant mixture in excess of this amount poses a threat to both your refrigerant supply and recovery equipment. The PureGuard uses a pass/fail approach when monitoring the refrigerant and is precisely calibrated to cut power to the recovery machine if it encounters R12 mixed with any substitute refrigerants. The PureGuard ignores the presence of the air, dyes or oils in the refrigerant sampled. At least 20 psi must be present in the vehicle's A/C system for the PureGuard to function. Otherwise, refrigerant cannot be introduced to the PureGuard's test chamber. If a vehicle's A/C system contains less than 20 psi, it is an indication that the vehicle's system is nearly depleted of refrigerant. Occasionally, erratic PureGuard operation or service code 002 display will be encountered when A/C system pressure is exactly 20 psi. If this occurs, simply cycle the on/off switch to reset the PureGuard. After the 30 second PureGuard warm-up cycle, proceed immediately with vehicle recovery operation. Feedback from the field has indicated PureGuard service code 002 will also be displayed if the oil drain port is not sealed. Make sure the "0" ring seal in the cap is in place and that the cap is tight. If the PureGuard fails to clear or if you experience any other problems operating the PureGuard, contact Kent-Moore Technical Service at 1-800-345-2233. The unit should not be returned without first contacting Kent-Moore to obtain return authorization. Refrigerant Disposal Locations: United States Refrigerant Reclamation Inc. 12420 North Green River Rd. Evansville, IN 47711 800-207-5931, FAX - 812-867-1463 Service and Repair Timing Chain: Service and Repair REMOVAL ^ Tools Required J 5825-A Crankshaft Sprocket Puller 1. Remove the timing cover. 2. Remove the crankshaft position sensor reluctor ring. 3. Remove the camshaft sprocket bolts. 4. Remove camshaft sprocket. 5. Remove timing chain. Page 3744 PROM - Programmable Read Only Memory: Application and ID Footnotes 251 Thru 300 [251] Hesitation or sag during the first two minutes of cold operation while vehicle is under moderate to heavy throttle drive away, or TCC chuggle. [252] Cold start-stall, hesitation, or sag when the engine coolant is between 36°F to 111°F (2°C to 44°C); or Inadequate AC performance when driving at a steady speed and throttle position, between 24 to 64 MPH, when the cruise control is not being used. [253] Lack of throttle response on trucks equipped with governors; or hot restart driveaway sag, both governor and non-governor trucks. [254] Intermittent stall after cold start; engine stalling on coast down; hesitation cold; or ECM CODES E22,E26,E32,E55,E70, and/or E85 [255] PROM I.D. 7080 KJ is also acceptable for PROM I.D. 5853 KJ only. Requires Throttle body service P/N 17067144, EGR valve] service P/N 17067108 (FED), 17067144 (CAL), Injector service kit P/N 17067976. [256] Requires Throttle body service P/N 17067142, EGR valve service P/N 17067107 (FED), 17068210 (CAL), Injector service kit P/N 17067976. [257] FOR CHUGGLE AT 40-45 CONDITION, USE PROM ONLY. FOR TIP-IN HESITATION ONLY, USE EGR VALVE ONLY - P/N 17078431. FOR COLD DRIVEABILITY HESITATION, USE BOTH PROM AND EGR. [258] REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 015 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 015 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [259] DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH USED SCANNER ID 5644 BUT HAD A [260] DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH USED SCANNER ID 5644 BUT HAD A [261] DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH USED SCANNER ID 5644 BUT HAD A [262] MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY AT TEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [263] MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [264] MODEL 2DDM TRANS. CARS - CHECK DLR. RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH PN 8650935 (BCC: DGAF). TRANSMISSIONS WITH TORQUE CONVERTERS WITH PN 8656959 (BCC: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED W [265] MODEL 2DDM TRANS. CARS - CHECK DLR. RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH PN 8650935 (BCC: DGAF). TRANSMISSIONS WITH TORQUE CONVERTERS WITH PN 8656959 (BCC: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED W [266] Vehicles equipped with Computer Controlled Emission System (C.C.E.S) experience a Check Engine Light coming on while idling, usually when idling time exceeds 2 minutes with transmission in gear in altitudes above 3000 feet. [267] Cold driveability, use with PROM 5854 KJ (G057). PROM I.D. 7080 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5853 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [268] Cold driveability, use with PROM 5853 KJ (G057). PROM I.D. 7079 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5854 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [269] Cold driveability, use with PROM 5861 KK (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. Page 1359 Malfunction Indicator Lamp: Service and Repair The Check Engine Lamp will be illuminated when the ignition switch is placed in the On position. When the engine is started, the lamp should go off. If the lamp remains on for 10 seconds or constantly after the engine is started, the self diagnosis system has detected a problem and has stored a code in the system Electronic Control Module (ECM). After diagnosis and repair, the ECM memory can be cleared of codes by removing the ECM fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the Off position. It should be noted, that if battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: All Technical Service Bulletins Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 2832 Electronic Spark Control (ESC) Circuit Circuit Description: The Code 43 circuit consists of two knock sensors with one wire that goes directly to the ECM. There are two Code 43 checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 4.4 volts. If voltage is either too high or too low for 2 or more seconds, Code 43 will set. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3800 rpm, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, Code 43 will set. Diagnostic Aids: The ECM applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the ECM, is able to read this signal as knock and incrementally retard spark. If the ESC system checks OK, but detonation is the complaint, See: Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Testing and Inspection Temperature Warning Lamp/Indicator: Testing and Inspection A bi-metal temperature switch located in the cylinder head controls the operation of a temperature indicator light. If the engine cooling system is not functioning properly and/or coolant temperature exceeds a predetermined value, the warning light will illuminate. If the light is not lit when the engine is being cranked, check for a burned out bulb, an open in the light circuit, or a defective ignition switch. If the light is lit when the engine is running, check the wiring between light and switch for a ground, defective temperature switch, or overheated cooling system. As a test circuit to check whether the bulb is functioning properly, connect a wire from the ground terminal of the ignition switch to the temperature indicator light circuit. When the ignition is in the START (engine cranking) position, the ground terminal is grounded inside the switch and the bulb will be lit. When the engine is started and the ignition switch is in the ON position, the test circuit is opened and the bulb is then controlled by the temperature switch. Page 4845 Vacuum Brake Booster: Service and Repair Power Brake Unit 1. Disconnect master cylinder assembly and vacuum hose from power brake unit. 2. Disconnect power brake unit pushrod from brake pedal. 3. Remove power brake unit attaching nuts from inside of vehicle. 4. Remove power brake unit. 5. Reverse procedure to install. Torque power brake unit and master cylinder mounting nuts to specification. Page 8550 Underhood Lamp: Testing and Inspection Troubleshooting Hints 1. Check condition of underhood lamp in-line fuse. Page 1213 85-93 Suction hose - 94855765 85-92 Discharge hose - 94845943 1985-88 Sprint, 1989-93 Metro (M) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 500 grams (1.10 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-86 - 91172081 87-88 - 91172079 89-93 - 96068480 Adapter Fittings: Low Side - 91172092 85-88 - High Side - 91172094 89-93 - High Side - 52467941 0-Rings: Compressor - Small 0-rings (6 required) - 91172095 - Large 0-ring - 96068915 Receiver/Dryer (2) - 96068488 Page 2939 Engine Wiring, LH Side Page 7431 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 3739 [171] Engine stall and/or hesitation after cold start. MUST BE ORDERED WITH SERVICE KIT P/N 10115773. [172] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [173] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [174] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [175] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [176] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [177] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [178] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [179] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [180] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [181] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [182] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [183] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [184] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [185] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [186] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [187] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [188] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED Engine - Shake At Low RPM & At Idle, Engine Mount Engine Mount: All Technical Service Bulletins Engine - Shake At Low RPM & At Idle, Engine Mount Group Ref.: Engine Mechanical Bulletin No.: 166102 Date: November, 1993 SUBJECT: ENGINE SHAKE AT LOW SPEEDS AND AT IDLE (MOUNT NEUTRALIZATION PROCEDURE) MODELS: 1988-92 S/T TRUCKS WITH 4.3L ENGINE (RPO LB4) This bulletin is being revised to change the service parts availability information. Previous divisional publication numbers were: Chevrolet 92-353-6 GMC Truck 92-6A-158 CONDITION Owners of some 1988-92 S/T Trucks equipped with a 4.3L engine (VIN Code Z) may comment about excessive engine shake slightly above idle (800-1800 RPM). CAUSE Due to the cylinder arrangement, design, and firing order, the 4.3L engine has inherent natural vibrations. Before attempting to repair any of these disturbances, it is necessary to compare it to another known good vehicle, same model, year, etc. Some engine shake is normal. However, if the engine shake is more than normal, it may be due to powertrain mount and/or exhaust system positioning and/or movement. The following procedure addresses the condition. CORRECTION This diagnosis is designed to identify engine mount ground out. Pay special attention to engine mounts, transmission mounts, and exhaust system hangers. The vibration or ground out location must be isolated. 1. Apply parking brake. 2. Block the front wheels. 3. Place the vehicle in DRIVE (1st gear for standard transmission). 4. Bring engine rpm up to 1500-2000, listen for ground out (knocks or booming noise) and/or increased vibrations. 5. If no ground out is found, repeat step 3 with transmission in REVERSE. CAUTION: DO NOT ACCELERATE AGAINST THE BRAKES FOR LONGER THAN 15 SECONDS. CARE SHOULD BE TAKEN NOT TO OVERHEAT THE ENGINE OR TRANSMISSION. ALSO, CARE SHOULD BE TAKEN DURING DIAGNOSIS DUE TO THE FACT THAT SOME DISTURBANCES MAY BE CREATED DURING BRAKE TORQUE THAT NORMALLY DO NOT EXIST. Note: Pay special attention to engine mounts making hard contact, check for proper clearance at tangs. If ground out or crushed mounts are confirmed, replace worn or torn components as required, refer to the neutralization procedure below. To neutralize the engine and align the exhaust system properly: 1. Allow vehicle to warm up fully. Raise vehicle and support with suitable safety stands. Page 8540 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 1206 f. TO INSURE AN ACCURATE CHARGE AMOUNT, IT IS IMPORTANT TO CLEAR THE ACR4 OF ANY REMAINING REFRIGERANT. Close the high side coupler valve and remove the high side hose from the vehicle. Then, open both the high and low side valves on the ACR4. After the pressures on both gages are at low side pressure, close the low side coupler valve. See Step G below, then remove the low side hose from the vehicle. Shut off the engine. Install the service port caps on the new fittings. These serve as a seal and can prevent system leaks. g. In the unlikely event that the low side fitting leaks when the coupler is removed, use the following procedure: 1. Immediately reinstall the coupler on the fitting. 2. Find the valve core remover J 34611-A. 3. Remove the coupler. 4. Use the double-ended valve core remover to turn the valve core pin counter-clockwise until the leak stops. 5. Install the cap. If the leak was substantial or continued for an extended period of time, it is highly recommended to evacuate and recharge the system to insure proper performance. If there is any question, the system can be rechecked by repeating Step F. h. Leak test any new port fittings, adapters, or valves that were installed, and any joints that were opened or repaired during the retrofit process, using tool J 39400. 6. Install the Retrofit Label The retrofit label (P/N 21030857, roll of 250) has been developed following SAF specifications to insure a smooth transition from R-12 to R-134a, and to insure a professional approach to the retrofit and a quality repair. Following the instructions in this bulletin will insure that the retrofit meets the SAE standards. Fill in the new label using a typewriter or a ball-point pen (see Figure 6). Select a location for the label that will be easily visible. Some suggested areas are the radiator support panel, an area near the existing R-12 charge label, or a flat surface near the high or low side service ports. The area selected should be a clean, underhood, painted sheet metal surface, and should be degreased and wiped down with a non-petroleum based cleaner. Do not install the label on a rubber surface. Apply the label, then apply the clear overlay to the label. Do not remove, cover, or render unreadable the existing R-12 charge label. DO cover the R-12 refrigerant charge amount on the existing label with an indelible, preferably black, marker. Platform Details Tires - Slipping on Rim Wheels: All Technical Service Bulletins Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Page 7490 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Automatic Transmission Neutral Safety Switch: Service and Repair Automatic Transmission 1. Remove battery ground cable. 2. Remove lower insulator panel. 3. Remove neutral start switch electrical connector. 4. Remove neutral start switch. 5. Reverse procedure to install, noting the following: a. Align actuator on the switch with holes in shift tube. b. Press down on front of switch until tangs snap into rectangular holes in the steering column jacket. c. Adjust switch by moving the gear selector to park. Page 7653 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Page 389 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 5601 The illustration presents a pictorial illustration of the bleed procedure. This new procedure replaces previous steering system bleed procedures. Locations Fusible Link: Locations RH Front Side Of Engine. LH Front Of Engine Applicable to: 4.3L/V6-262 Turbo Engine Page 4359 Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of retainer from slot or flat of locknut, then remove locknut from housing tube, Fig. 6. 3. Disengage tang of retainer from slot or flat of adjusting nut, then remove retainer. 4. Using tool shown in Fig. 6, remove adjusting nut from housing tube. Remove thrust washer. 5. Pull hub and drum assembly off axle housing. Remove oil seal and discard. 6. Using a suitable steel bar and an arbor press, press inner bearing cup from hub. Removing bearing retainer ring 7. Using a suitable pliers, remove outer bearing retaining ring, Fig. 10. 8. Using an old axle shaft or equivalent, drive on axle shaft spacer to remove outer bearing assembly from hub. 9. Position axle shaft spacer and outer bearing into hub, ensuring larger side of bearing faces outer end of hub. 10. Position outer bearing cup into hub with thin edge facing toward outer end of hub, then press cup into hub. 11. Install retaining ring, then press cup into contact with ring. 12. Drive inner bearing cup into hub, then install new oil seal. 13. Reverse Steps 1 through 5 to complete installation, then adjust wheel bearings as outlined in ``Wheel Bearing, Adjust'' procedure. Axle Assembly REAR DRIVE AXLE 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Shaft Replace REAR DRIVE AXLE Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ROCKER ARM NUT TORQUE Valve Rocker Arm Nuts ....................................................................................................................... ................................................ 27 Nm (20 lb. ft.). Restraints - Child Seat Top Teather Attachment Kits Child Seat Tether Attachment: Technical Service Bulletins Restraints - Child Seat Top Teather Attachment Kits Bulletin No.: 99-09-40-004a Date: April 12, 2005 INFORMATION Subject: Top Tether Hardware Package for Child Restraint Seats Models: 1989-2002 Passenger Cars, Light Duty Trucks and Multi-Purpose Passenger Vehicles (Except EV1 and Prizm) Supercede: This bulletin is being revised to add the 2000-2002 model years. Please discard Corporate Bulletin Number 99-09-40-009 (Section 09 - Restraints). Important: GM of Canada and IPC Dealers are not authorized to utilize this service bulletin. Beginning in August, 1997 General Motors began providing Child Restraint Seat Top Tether Hardware Packages to customers in the United States who requested them. The Top Tether Hardware Package contains the necessary hardware for anchoring a forward facing child restraint seat top tether. One Child Restraint Seat Top Tether Hardware Package will be provided per vehicle to the retail customer at no charge for installation. Charges for installation of additional Top Tether Hardware Packages per vehicle are the responsibility of the customer. Most forward facing child restraint seats (CRS) sold in the United States prior to calendar year 1999 were not sold with top tether straps, but have provisions for them. Top tethers, which are required in Canada, can help to better secure the seat in the vehicle. When a forward facing CRS including a top tether is used, specially designed components must be used to secure the child seat top tether. These components are included in the Hardware Package from GMSPO. Top tethers are not normally required or used with rearward facing infant restraint seats. Rearward facing infant restraint seats should never be secured in the front seat of an air bag equipped vehicle unless the vehicle is equipped with an air bag de-activation (shut-off) switch and the switch has been used to turn the air bag off. Should a retail customer request installation of a Tether Hardware Package at the time of sale or delivery, it is to be installed at no charge to the owner. The labor to install a Tether Hardware Package prior to delivery of a new vehicle to the customer is considered to be part of the delivery "get ready process", and as such, is not claimable. Claiming for the cost and applicable handling allowance of the proper Tether Hardware Package used in the installation is allowed. If the customer requests installation of a Tether Hardware Package some time after delivery, the package is to be provided free of charge. Hardware Packages include installation instructions which are easily followed and can be installed by most customers. However, should the customer request the dealership's assistance to install the Tether Hardware Package, it is to be installed at no charge to the customer and the labor may be claimed. All claims submitted for installation labor of an approved Tether Hardware Package must be supported by a signed customer work order. Additional Hardware Packages and installation charges are the responsibility of the customer. In addition, passenger vehicle deliveries, including vans and sport utilities for daily rental usage, may have one tether hardware package supplied. Additional packages are the owner's responsibility. Dealers may claim appropriate parts under these circumstances. Sufficient quantities of parts should be ordered in advance of the arrival of vehicles to avoid delays. Important: When installing a Child Restraint Seat Top Tether Hardware Package, follow the installation instructions included in the package. Additional information about specific mounting locations and installations may be available in the Seat Belt Section (Sections 9, 10-10, 10-11 or 10A) I of the appropriate Service Manual, or the Restraints section of SI. Any questions regarding this policy should be directed to your Area Manager, Parts or Service. Parts Information For Top Tether Hardware Package part numbers and usage, see Group 14.870 (passenger cars & U-van), or Group 16.710 (Light Duty Truck) of the appropriate GMSPO Parts Catalog. In addition, they can also be found in Accessories Group 21.042. Page 2475 Ignition Control Module: Description and Operation PURPOSE The distributor reference signal provides the ECM with both engine RPM and crankshaft position information. This enables the ECM to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the ECM receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the ECM will not operate the injector. Page 7426 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Locations Switch: Locations Anti-Lock Brake Components. In Front Axle Applicable to: 1992 Blazer & Jimmy Page 4611 Hydraulic Assembly: Service and Repair Four Wheel Anti-Lock Brake System The EHCU/BPMV module is not serviceable and must be replaced as a unit. Fig. 54 EHCU/BMPV Mounting. Astro/Safari Refer to Fig. 57 when replacing this unit. 1. Remove washer tank attaching bolts, then position aside. 2. Remove EHCU/BPMV electrical connectors. 3. Disconnect module brake lines. Use caution not to get brake fluid on paint or electrical connections. 4. Remove upper to lower bracket assembly attaching bolts. 5. Remove EHCU/BPMV module and upper bracket assembly from vehicle. 6. Remove upper mounting bracket to EHCU/BPMV module attaching bolts. 7. Reverse procedure to install, noting the following: a. Torque EHCU/BPMV module to bracket attaching bolts to 5 ft. lbs. b. Torque EHCU/BPMV bracket assembly attaching bolts to 20 ft. lbs. c. Torque brake line fittings to 16 ft. lbs. d. Bleed EHCU/BPMV module as outlined under MAINTENANCE PROCEDURES/BLEEDING EHCU/BPMV MODULE. Steering - Column Popping Noise Steering Column Bearing: All Technical Service Bulletins Steering - Column Popping Noise Group Ref.: Steering/Suspension Bulletin No.: 333210A Date: December, 1993 SUBJECT: STEERING COLUMN POPPING NOISE (REPLACE UPPER BEARING INNER RACE SEAT) MODELS: 1992-93 PASSENGER CARS EXCEPT CHEVROLET CAVALIER, GEO AND PONTIAC LEMANS 1992-93 LIGHT DUTY TRUCKS EXCEPT GEO TRACKER This bulletin is being re-published to add the labor time for Labor Operation Number E7310. Vehicles affected have TILT steering columns (round style) with the exception of the "W" series (square style). CONDITION: Some owners of vehicles with integral TILT steering columns may hear a pop noise when turning. The noise occurs specifically when the driver is making normal steering turns in either direction and generally when the steering wheel is returning to center. CAUSE: The upper bearing inner race seat under certain conditions may cause a pop noise. The part may have a burr on the inside skirt. CORRECTION: To verify that the upper bearing inner race seat is the cause of the pop noise in the steering column, use the following method: 1. Engage the park brake and start the engine. 2. Point the wheels of the vehicle straight ahead. 3. While listening for a pop noise, rotate the steering wheel in either direction to the wheel stop. Slowly return the wheel back to center. If the noise is not heard, drive the vehicle at a slow speed listening for the noise to occur. Important: When the steering column is warm, the pop noise will be more audible. 4. If a pop noise is heard, replace the upper bearing inner race seat with P/N 7815184. Return the steering wheel back to center with the wheels of the vehicle pointed straight ahead. Turn the ignition lock cylinder to "LOCK" position and then begin the repair. Refer to Section 3F5A/3F5B in the Service Manual to replace the upper bearing inner race seat. Parts are currently available from GMSPO. Labor Operation Number: E7310 Labor Time: 0.6 hrs. For GMC Truck ONLY, use: T7681 Labor Time: 0.4 hrs. (With SIR add .2 hrs.) Page 7537 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 7692 Audible Warning Device: Electrical Diagrams Audio Alarms 4L60 & 4L60-E Transmission Transmission Speed Sensor: Specifications 4L60 & 4L60-E Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Page 5620 Power Steering Pump: Service and Repair Vane Type Power Steering Pump Flushing Power Steering System 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return hose at pump inlet connector and plug connector port on pump. Position hose in large container. 3. While an assistant is filling reservoir with new power steering fluid, run engine at idle. turn steering wheel from stop to stop. Do not contact wheel stops or hold wheel in a corner as fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 4. Install all pipes and hoses. Fill system with new power steering fluid and bleed system as outlined under SYSTEM BLEEDING. 5. Operate engine for 15 minutes. 6. Remove pump return hose at pump inlet and plug connection on pump. While refilling reservoir, check draining fluid for contamination. If foreign material is still evident, replace all hoses, disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. System Bleeding 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine Off. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. Locations EGR Valve Position Sensor: Locations Engine Wiring, LH Side Page 2775 Engine Control Module: Component Tests and General Diagnostics ECM QDR Check Procedure ECM QDR Check Procedure Page 8414 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 1287 Figure 7 Figure 8 Figure 9 Figure 10 Page 6908 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 2872 Oxygen Sensor: Service and Repair NOTE The Heated Oxygen Sensor (HO2S) uses a permanently attached pigtail and connector. This pigtail should not be removed from the Heated Oxygen Sensor (HO2S). Damage or removal of the pigtail or connector could affect proper operation of the oxygen sensor. Take care when handling the Heated Oxygen Sensor (HO2S). The in-line electrical connector and louvered end must be kept free of grease, dirt, or other contaminants. Also, avoid using cleaning solvents of any type. Do not drop or roughly handle the heated oxygen sensor. If the heated oxygen sensor pigtail wiring, connector or terminal is damaged, the entire oxygen sensor assembly must be replaced. Do not attempt to repair the wiring, connector or terminals. In order for the sensor to function properly, it must have provided to it a clean air reference. This clean air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors or terminals could result in the obstruction of the air reference and degraded oxygen sensor performance. CAUTION The following guidelines should be used when servicing the heated oxygen sensor: ^ Do not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor causing poor performance. Also, the sensor pigtail and harness wires must not be damaged in such a way that the wires inside are exposed. This could provide a path for foreign materials to enter the sensor and cause performance problems. ^ Neither the sensor or vehicle lead wires should be bent sharply or kinked. Sharp bends, kinks, etc., could block the reference air path through the lead wire. ^ Do not remove or defeat the oxygen sensor ground wire (where applicable). Vehicles that utilize the ground wired sensor may rely on this ground as the only ground contact to the sensor. Removal of the ground wire will also cause poor engine performance. ^ The Heated Oxygen Sensor (HO2S) may be difficult to remove, when engine temperature is below 48°C (120°F). Excessive force may damage threads in exhaust manifold or exhaust pipe. NOTE The engine harness may be repaired using Packard's Crimp and Splice Seals Terminal Repair Kit J 38125-A. Under no circumstances should repairs be soldered since this could result in the air reference being obstructed. Remove or Disconnect 1. Negative battery cable. 2. Electrical connector releasing locking tab. 3. Carefully back out oxygen sensor. Install or Connect NOTE A special anti-seize compound is used on the Heated Oxygen Sensor (HO2S) threads. The compound consists of liquid graphite and glass beads. The graphite will tend to burn away, but the glass beads will remain, making the sensor easier to remove. New, or service replacement sensors will already have the compound applied to the threads. If a sensor is removed from an engine, and if for any reason it is to be reinstalled, the threads must have anti-seize compound applied before reinstallation. 1. Coat threads of heated oxygen sensor with anti-seize compound (GM PIN 5613695 or equivalent), if necessary. 2. Sensor, and torque to 41 Nm (30 ib. ft.). 3. Electrical connector. 4. Negative battery cable. Page 665 Throttle Position Sensor: Adjustments N/A: TPS is not adjustable on this engine. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Gauge: All Technical Service Bulletins Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 8452 Stoplamp Switch Installation Page 8129 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Interior - Wind Noise At Side Marker Lamps Side Marker Lamp: Customer Interest Interior - Wind Noise At Side Marker Lamps Number: 92-194-10 Section: 10 Date: May 1992 Corporate Bulletin No.: 261503 ASE No.: B1 Subject: WIND NOISE AT SIDE MARKER LAMPS Model and Year: 1990-92 S/T TRUCKS WITHOUT SPORT GRILLES Owners of some 1990-1992 S/T vehicles may comment on a wind whistle through the grille in the area of the side marker lamp(s). This condition may occur as air flows through the side marker lamp bracket(s). The whistling sound is intermittent and is affected by vehicle speed/direction and wind velocity/direction. To correct this condition, it is necessary to apply sealer along the entire leading edge of the side marker lamp(s). This eliminates the air flow through the mating surfaces of the lamp bracket(s) and the grille. SERVICE PROCEDURE: 1. Remove the grille. A. Remove the four grille to radiator suppod fasteners located across the top of the grille and the four fasteners located within the egg crate area of the grille. Page 8394 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 3174 When performing service on the accelerator control cable, observe the following: - The retainer must be installed with the tangs secured overhead of the stud. - The conduit fitting at both ends of the cable must have the locking tangs expanded and locked in the attaching holes. - The braided portion of the accelerator cable assembly must not come in contact with the front of the dash sealer during assembly, repair, or replacement of the assembly. - The flexible components (hoses, wires, conduits, etc.) must not be routed within 50 mm (2 inches) of the moving parts of the accelerator linkage outboard of the support unless the routing is positively controlled. REMOVE/DISCONNECT - Retainer from throttle lever stud - Retainer locking tangs from support bracket - Retainer from accelerator pedal rod or release cable from rod. - Retainer locking tangs from dash panel INSTALL/CONNECT - Retainer to dash panel. - Retainer to accelerator pedal rod or connect cable in rod slot. - Retainer to support bracket. - Retainer to throttle lever stud or connect cable to pulley. Page 7291 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 3028 Throttle Position Sensor: Adjustments N/A: TPS is not adjustable on this engine. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Page 1800 5. Replace the previous transmission mount with the revised mount (P/N 22145724 - for two wheel drive only) as shown in Figure 4. Some residual vibrations may be normal. Compare with a vehicle of same model, year, engine/transmission combination, etc. to get a feel for what is normal. SERVICE PARTS INFORMATION Parts are expected to be available from GMSPO on 8/2/93. WARRANTY INFORMATION Page 1381 1. Center the repair unit over the injury as a reference and outline an area larger than the unit so that buffing will not remove the crayon marks. 2. Remove the repair unit. 3. DO NOT overlap previous or multiple repair units. 4. Consult your repair material supplier for proper repair unit selection. Buffing 1. To prevent contamination and preserve the outline, buff within the marked area thoroughly and evenly with a low speed buffing tool using a fine wire brush or gritted rasp. 2. Buff to a smooth velvet surface (RMA #1 or #2 buffed texture). 3. Use caution not to gouge the inner liner or expose casing fabric. 4. Remove any buffing dust with a vacuum cleaner. 5. Consult your repair material supplier for a proper buffing tool. Cementing Apply chemical cement according to the repair material manufacturer's procedures. Repair Unit Application Specifications Brake Master Cylinder: Specifications Master Cylinder Mounting Nut 20 ft.lb Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Page 1137 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Page 82 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 5277 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 5113 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 753 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 8541 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 5086 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Slip Yoke/U-Joint - Replacement and Servicing Slip Yoke: Technical Service Bulletins Slip Yoke/U-Joint - Replacement and Servicing File In Section: 4 - Drive Axle Bulletin No.: 46-41-01 Date: September, 1994 INFORMATION Subject: Slip Yoke Replacement and U-Joint Servicing Models: 1995 and Prior Light Duty Trucks U-joints that are pressed out of the propeller shaft or slip yoke must not be re-used. When it is necessary to press out the u-joint to replace a slip yoke, a new u-joint must be installed. A new u-joint is necessary as the bearing cup seals and slingers are easily damaged. If these components are damaged, dirt and water can contaminate the bearing causing early bearing wear-out. Replacement of the rear u-joint is not required if the retaining straps holding the u-joint to the rear axle pinion flange are removed. Light duty trucks make use of three types of yokes: 1. Vented slip yoke. This yoke can be identified by a small hole in the center of the slip yoke welch plug. This yoke uses grease for internal lubrication. The internal splines of the yoke should be coated with a light covering of grease before installation to the output shaft. A small amount of grease may be forced from the vent hole during operation. No attempts should be made to plug the vent hole. 2. Non-vented slip yoke. This yoke has no vent hole and relies on transmission or transfer case fluid for internal lubrication. Grease should not be used on the yoke internal splines as it may contaminate the transmission or transfer case fluid. 3. Bolted or fixed yoke. This yoke does not slide so it needs no internal lubrication. The transmission/transfer case output shaft seal should be inspected for damage before installing the yoke. The seal lips should also be greased before yoke installation for longer seal life and better performance. Page 7717 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: All Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Page 8059 Page 7524 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 173 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Page 6596 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 8366 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 3612 Rear Of Engine Page 4879 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Technician Safety Information Hose/Line HVAC: Technician Safety Information WARNINGS: - Air conditioning systems contain Refrigerant-12. This is a special mixture which requires special handling procedures to avoid personal injury. - Always wear goggles and wrap a clean cloth around fittings, valves, and connections when performing work that involves opening the refrigerant system. - Always work in a well ventilated area and avoid breathing any refrigerant fumes. - Do not weld or steam clean on or near any vehicle-installed air conditioning lines or components. - If Refrigerant-12 should come in contact with any part of the body, flush the exposed area with water and immediately seek medical help. CAUTIONS: - All Refrigerant-12 drums are shipped with a heavy metal screw cap. The purpose of the cap is to protect the valve and safety plug from damage. It is good practice to replace the cap after each use of the drum. - If it is necessary to transport or carry any container of Refrigerant-12 in a vehicle, do not carry it in the passenger compartment. - See the manufacturer's guide-lines for storage, transportation and the maximum temperature to which the container can be exposed. - If the occasion ever arises to fill a small Refrigerant-12 drum from a large one, never fill the drum completely. Space should always be allowed above the liquid for expansion. HP Engine Evaporative Emission Control Canister: Locations HP Engine Engine Compartment Components LH Front Of Engine Compartment Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 HP Engine Fuels - Effect of Volatility on Driveability Fuel: Customer Interest Fuels - Effect of Volatility on Driveability Number: 93-31-6C Section: 6C Date: OCT. 1992 Corporate Bulletin No.: 249128R ASE No.: A1, A8 Subject: EFFECT OF FUEL VOLATILITY ON DRIVEABILITY CONDITIONS Model and Year: ALL MODEL YEARS, ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-281-6C, DATED SEPT. 1992. THE 1993 MODEL YEAR HAS BEEN ADDED. ALL COPIES OF 92-281-6C SHOULD BE DISCARDED. Recent changes in EPA regulations have effectively lowered the maximum allowable fuel volatility. Volatility, which can be defined as a gasoline's ability to change from a liquid to a vapor, directly affects the amount of evaporative emissions produced by the fuel. Higher volatility means that more unburned hydrocarbons will be released into the atmosphere. Unfortunately, reducing fuel volatility can cause problems during cold engine operation when low temperatures impede the fuel's ability to vaporize and burn. Two terms are often used to describe volatility characteristics. These are: Distillation Curve A graph showing the relationship between temperature and the percentage of fuel evaporated. The fuel components that boil at relatively low temperatures (below about 90 degrees F) are known as the "light ends", and are essential for good cold engine performance. The "heavy ends", which begin to boil at about 300 degrees F, contain the most energy but are more difficult to burn. Laboratory analysis is usually required to determine the distillation curve of a gasoline sample. - Reid Vapor Pressure (RVP) RVP is the pressure (psi) that vaporized fuel exerts within a sealed container as it is heated to 100 degrees F. The higher the RVP the higher the fuel volatility. While RVP is readily tested in the field, fuels of the same RVP can have different distillation curves and cold driveability characteristics. Fuel volatility will vary depending on geographic location and time of year (fuel intended to be used in higher ambient conditions is formulated with less volatility). This can make cold driveability as big a problem during summer months as during the winter. There may be additional variation in the volatility characteristics of pump gasoline, caused by the differences in fuel manufacturers, blends and storage times. As EPA fuel volatility standards are lowered, variations between fuels (which may further reduce volatility) becomes a critical factor influencing cold engine performance. No matter how thoroughly the relationship between fuel quality and cold driveability is understood, eliminating fuel quality as an issue can be difficult, because: TOOLS WHICH TEST FUEL VOLATILITY MEASURE ONLY RVP, NOT THE DISTILLATION CURVE. The distillation curve has a greater effect on cold driveability than RVP. THE CUSTOMER MAY PERCEIVE RAISING THE FUEL QUALITY ISSUE AS AN ATTEMPT TO EVADE HIS PROBLEM. This may cause difficulty in getting accurate fuel usage information. WATER, AND OTHER TYPES OF FUEL CONTAMINATION, MAY CAUSE CONTINUED DRIVEABILITY COMPLAINTS. - The problem symptoms may remain even though the vehicle has been refueled several times with a quality gasoline. CUSTOMER CONCERNS CONDITION: Poor Cold Engine Operation, symptoms may include; hard start/extended crank, stalling, backfiring, hesitation and/or lack of power. POSSIBLE CAUSE: Low volatility fuel will not vaporize sufficiently to allow normal combustion. CORRECTION: Replace Fuel. DIAGNOSTIC PROCEDURE: 1. Perform basic system checks in section 6E of the service manual. 2. Check for service bulletins which relate to cold driveability issues specific to the problem vehicle. Page 2967 The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/OXYGEN SENSOR TESTING. Page 4866 Figure 7 Figure 8 Figure 9 Figure 10 Wheels (Steel) - Damage Due to Improper Mounting Wheels: All Technical Service Bulletins Wheels (Steel) - Damage Due to Improper Mounting Number: 92-232-3E Section: 3E Date: JUNE 1992 Corporate Bulletin No.: 233002 ASE No.: A4 Subject: AVOIDING DAMAGE TO STEEL WHEELS FROM IMPROPER WHEEL/TIRE CHANGING TECHNIQUES Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH STEEL WHEELS It is important to use proper procedures to prevent damage to either the tire mounting surface or the wheel mounting holes. Damage can result from the improper wheel attachment or tire mounting techniques on vehicles with steel wheels. 1. IMPROPER TIRE CHANGING TECHNIQUES: It takes about 70 seconds for the air to completely exhaust from a large tire. If the technician doesn't wait this amount of time after removing the valve core, the bead breaker on the tire change could put enough force on the tire to bend the wheel at the mounting surface. Such damage can result in vibration, shimmy, and under severe usage (i.e. police vehicle) lead to cracking. 2. OVER TORQUING OF THE WHEEL NUTS: The service specification for wheel nuts is listed in the Service Manuals. Some wheels have been observed with wheel nuts that were over torqued by as much as 50 percent. This may damage the wheel mounting holes and may also lead to cracks. I. PROPER TIRE CHANGING TECHNIQUES: Completely deflate the tire before attempting to break the tire bead loose. MOUNTING SURFACE CHECKING PROCEDURE Page 5473 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 4086 of transmission fluid (ATF), (DEXRON(R)VI) (fluid) that is to be charged for the flush portion of the repair should not exceed the allowable charge for 7.5 L (2 gal) of fluid. This expense should be shown in the Parts Section of the warranty claim document. The Seven digit Alpha/Numeric flow code, i.e. A10DFB2, "MUST" be written on the job card and placed in the comments section of the warranty claim. Any repair that requires the technician to contact the Product Quality Center (PQC) must also include the seven digit flow code. The agent will request the seven digit flow code and add the information to the PQC case prior to providing authorization for the warranty claim. The Seven digit Alpha/Numeric flow code, i.e. A10DFB2, "MUST" be written on the job card, entered in the warranty claim labor operation Flush Code additional field (when available) and placed in the comments section of the warranty claim. Any repair that requires the technician to contact the Product Quality Center (PQC) must also include the seven digit flow code. The agent will request the seven digit flow code and add the information to the PQC case prior to providing authorization for the warranty claim. Disclaimer Page 3666 Transmission Speed Sensor: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks utilize a warning light on the instrument panel in place of the conventional dash indicating gauge to warn the driver when the oil pressure is dangerously low. The warning light is wired in series with the ignition switch and the engine unit-which is an oil pressure switch. The oil pressure switch contains a diaphragm and a set of contacts. When the ignition switch is turned on, the warning light circuit is energized and the circuit is completed through the closed contacts in the pressure switch. When the engine is started, build-up of oil pressure compresses the diaphragm, opening the contacts, thereby breaking the circuit causing the light to go out. Page 1324 Figure 7 Figure 8 Figure 9 Figure 10 Capacity Specifications Clutch Fluid: Capacity Specifications Fill the clutch master cylinder to the "Full" or "MAX" mark on the reservoir. Do not overfill. Caution: Should accidental spillage occur, rinse the area thoroughly with water. Pay special attention to any electrical wires, parts, harnesses, rubber or painted surfaces. Page 5753 Do Not Replace coil-over shock absorbers displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom of the lower shock absorber tube or the coil-over shock absorber components and not originating from the shaft seal (located at the top of the coil-over shock tube). 2. Light film/residue on the shock absorber tube, but not on the spring seat and originating from the shaft seal. Replace coil-over shock absorbers displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the lower shock tube and originating from the shaft seal. 4. An extreme, wet film of oil covering the shock absorber tube and pooling in the spring seat and originating from the shaft seal. Struts Do Not Replace Struts displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom of the strut tube or on other strut components and not originating from the shaft seal. 2. Light film/residue on the strut tube, but not on the spring seat and originating from the shaft seal. Replace Struts displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the strut tube and originating from the shaft seal (located at the top of the strut tube). 4. Extreme wet film of oil covering the strut tube and pooling in the spring seat and originating from the shaft seal. Correction Use the information published in SI for diagnosis and repair. Use the applicable published labor operation. Disclaimer Restraints - Passenger Presence System Information Seat Occupant Sensor: Technical Service Bulletins Restraints - Passenger Presence System Information INFORMATION Bulletin No.: 06-08-50-009F Date: December 23, 2010 Subject: Information on Passenger Presence Sensing System (PPS or PSS) Concerns With Custom Upholstery, Accessory Seat Heaters or Other Comfort Enhancing Devices Models: 2011 and Prior GM Passenger Cars and Trucks Equipped with Passenger Presence Sensing System Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 06-08-50-009E (Section 08 - Body and Accessories). Concerns About Safety and Alterations to the Front Passenger Seat Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE THE SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER THE SEAT COVERS OR SEAT-RELATED EQUIPMENT. ANY ALTERATIONS TO SEAT COVERS OR GM ACCESSORIES DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. The front passenger seat in many GM vehicles is equipped with a passenger sensing system that will turn off the right front passenger's frontal airbag under certain conditions, such as when an infant or child seat is present. In some vehicles, the passenger sensing system will also turn off the right front passenger's seat mounted side impact airbag. For the system to function properly, sensors are used in the seat to detect the presence of a properly-seated occupant. The passenger sensing system may not operate properly if the original seat trim is replaced (1) by non-GM covers, upholstery or trim, or (2) by GM covers, upholstery or trim designed for a different vehicle or (3) by GM covers, upholstery or trim that has been altered by a trim shop, or (4) if any object, such as an aftermarket seat heater or a comfort enhancing pad or device is installed under the seat fabric or between the occupant and the seat fabric. Aftermarket Seat Heaters, Custom Upholstery, and Comfort Enhancing Pads or Devices Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE ONLY SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT RELEASED AS GM ACCESSORIES FOR THAT VEHICLE. DO NOT USE ANY OTHER TYPE OF SEAT COVERS OR SEAT-RELATED EQUIPMENT, OR GM ACCESSORIES RELEASED FOR OTHER VEHICLE APPLICATIONS. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ACCESSORIES, INCLUDING ANY WARRANTY REPAIRS MADE NECESSARY BY SUCH USE. Many types of aftermarket accessories are available to customers, upfitting shops, and dealers. Some of these devices sit on top of, or are Velcro(R) strapped to the seat while others such as seat heaters are installed under the seat fabric. Additionally, seat covers made of leather or other materials may have different padding thickness installed that could prevent the Passenger Sensing System from functioning properly. Never alter the vehicle seats. Never add pads or other devices to the seat cushion, as this may interfere with the operation of the Passenger Sensing System and either prevent proper deployment of the passenger airbag or prevent proper suppression of the passenger air bag. Disclaimer Page 6755 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7318 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Locations LH I/P Harness Wiring Page 6258 Removing And Installing Shaft Seal O-Ring 7. Remove and discard the seal seat O-ring from the compressor neck using O-ring remover J 9553-01. 8. Recheck the shaft and inside of the compressor neck for dirt or foreign material and be sure these areas are perfectly clean before installing new parts. Clean Thoroughly clean O-ring seal groove in front head. Page 7480 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7030 * We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Important Additional time or payment beyond established allowances in this bulletin will not be allowed. - The use of a razor blade on large flat surfaces is not recommended because of the potential to chip. gouge or otherwise damage the primer surface. If razor blade technique is used, the application of a "guide coat" prior to wet sanding should also be used. Note: Chemical stripping is not recommended because of negative impact to moldings, non-metal components, ELPO and environmental concerns. 4. Blow off with air to remove all dirt and sanding residue from cracks and vehicle surface. 5. Clean sanded surface with an appropriate wax and grease remover. 6. Tack wipe entire area to be primed. 7. Spray entire prepared area with a coat of anti-corrosion primer to ensure maximum adhesion and corrosion resistance. Be sure to cover any bare metal surfaces exposed during the sanding operations. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 615S/616S, BASE DE17/PR8O/DA18, PPG DP4O/DP401, or equivalent. V.O.C. materials would be: DuPont 615S/616S, BASF DE15/PA16/PRB0, PPG DCP21/DCX211 or equivalent. 8. Apply two to three medium wet coats of primer surfacer to the primed surface of the vehicle, following the manufacturer's instructions for application and film build requirements. Important Failure to apply primer surfacer will likely result in future delamination. Typical materials for this application would be: DuPont 1120S/1130S/1125S, BASF DP20/PR80/PH36, PPG K36/DT870/K201, or equivalent. V.O.C. materials would be: DuPont 210S, BASF HP400, PPG DCP21/DCX211, or equivalent. 9. After allowing adequate drying time, wet sand with 400 grit (or finer) or dry sand with 320 grit (or finer) sandpaper. 10. Repeat steps 4 through 6. 11. Apply a medium coat of corrosion resistant primer sealer (tintable base) to the entire surface to be refinished. This will provide maximum adhesion, uniform color coating and corrosion protection to areas "sanded through" during wet sanding. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 2610S/2605S, BASF DP21/DH6O/PR80, PPG DP40/DP402 or equivalent. V.O.C. materials for this application would be: DuPont 21255, PPG DPW1834 or equivalent. 12. Apply two to three medium wet coats of color (or until primer color is hidden). Follow manufacturer's instructions and recommended dry times. 13. If vehicle has basecoat/clearcoat paint, apply clearcoat. Follow manufacturer's instructions and recommended dry times. 14. After sufficient air or force dry time, unmask the vehicle. 15. Finesse/polish as required. 16. Reinstall all previously removed items. 17. Wash and prepare the vehicle for delivery. HARDWARE ITEMS REMOVAL LIST Note: Some technicians may apply a small cord (wire, plastic tube, etc.) behind or underneath moldings that remain on the vehicle to improve sanding and painting. If the vehicle paint system is baked with cord in place, damage to some moldings may occur. If this technique is used, DO NOT BAKE Page 2120 Spark Plug Wire: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Page 8597 Rear Window Release & Defogger Components. Below Cigar Lighter Applicable to: 4Door Blazer & Jimmy Page 6302 Control Assembly: Symptom Related Diagnostic Procedures Temperature Control Effort A kinked control cable, a binding valve or a faulty control assembly are possible causes of excessive temperature control lever effort. For an organized diagnosis procedure and an effective "fix" for too little temperature control effort, refer to accompanying figure. Diagram Information and Instructions Vacuum Vent Valve: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 5156 Fuse And Circuit Breaker Identification A/T - Intermittent Downshift/Slip/Cycling Diagnosis Fan Clutch: All Technical Service Bulletins A/T - Intermittent Downshift/Slip/Cycling Diagnosis File In Section: 07 Transmission/Transaxle Bulletin No.: 99-07-30-016B Date: October, 2002 INFORMATION Subject: Diagnostic Information For Intermittent Transmission Downshift, Slip, Busy/cycling TCC or Noisy Cooling Fan Models: 1999-2000 Cadillac Escalade 2002-2003 Cadillac Escalade, Escalade EXT 1988-2003 Chevrolet Astro, Blazer, S-10, Silverado, Suburban 1989-2003 Chevrolet/Geo Tracker 1995-2003 Chevrolet Tahoe 1996-2003 Chevrolet Express 1988-1994 GMC S-15 1988-1999 GMC Suburban 1988-2003 GMC Safari, Sierra 1995-2003 GMC Sonoma, Yukon, Yukon XL 1996-2003 GMC Savana 1999-2001 GMC Envoy 1991-2001 Oldsmobile Bravada 2003 HUMMER H2 with Air Conditioning This bulletin is being revised to change the Model information and text. Please discard Corporate Bulletin Number 99-07-30-016A (Section 07 - Transmission/Transaxle) Some customers may comment that at times the transmission seems to slip, or that there is a loud roar from the engine with slow acceleration. This condition is most noticeable after the vehicle has sat idle for 12 or more hours, or on hot days when the A/C is on and the vehicle moves slowly with traffic. Typical comments from customers may include the following conditions: ^ Intermittent slipping ^ Intermittent downshift followed by an upshift, both with no apparent reason ^ Busyness or cycling of the TCC (torque converter clutch) at steady throttle conditions and on a level roadway ^ Noisy cooling fan The type of concern described above requires further definition. The customer should be asked the following questions: ^ Is the situation more pronounced with higher vehicle loads such as when pulling a trailer? ^ Do warmer ambient temperatures make the situation more pronounced? ^ When the condition occurred, did you have the A/C on, and were you driving in stop and go city traffic? ^ Does the condition exhibit itself on the first start-up after sitting more than eight hours? If the customer indicates that these conditions apply, and your observation confirms that the vehicle is operating properly, provide the customer with the vehicle operating description included at the end of this bulletin. Further action may not be necessary. A service procedure follows if further definition is required. Diagnostic Aids Cooling fan operation or the resulting sound varies. The cooling fan clutch may be described as a continuously variable clutch. If the vehicle engine is running, the fan blade is always turning unless the fan clutch is non-functional. The speed of the fan in relation to engine speed is temperature dependent. Page 4238 Carrier Bearings: Adjustments 4 - Pinion Fig. 3 Installing shims To adjust differential side bearing preload, change thickness of right and left shims equally so original backlash is not disturbed. 1. Ensure side bearing surfaces are clean and free of burrs. 2. Apply suitable lubricant to side bearings. If original bearings are to be reused, original outer races should also be used. 3. Install differential case in carrier, with bearing outer races in position. 4. Install left bearing cap and cap attaching bolts loosely so case may be moved during adjustment. 5. Measure original spacers and subtract .004 inch from each reading. Use caution not to interchange right and left spacers. 6. Select a service spacer for each side equal to thickness of original shim minus .004 inch, then install shim as shown in Fig. 3. Ensure flat edge of spacer faces against housing. 7. At this point, bearings should have no play and no drag (zero preload). If zero preload is not present, shims should be added or removed equally from both sides as necessary. 8. Check case for zero endplay using a dial indicator. If shim installation causes excessive pinion to ring gear clearance, select thinner left shim and add difference to right side. Keep total shim thickness at a value equal to that obtained in step 6. 9. Install both bearing caps and cap attaching bolts. Torque bolts 40 ft. lbs. Fig. 4 Gear tooth contact pattern check 10. If pinion was not removed, check backlash and tooth pattern as follows: Locations Audio Alarm Module: Locations On Convenience Center Page 3206 Fuels Oxygenated fuels, with methanol and/or ethanol blended into the gasoline have lower energy and thus reduce fuel economy. Typically there is about a 1 MPG penalty for a vehicle which gets 25 to 30 MPG on 100 percent gasoline. Using fuels of a lower octane than the vehicle was calibrated to will cause increased "KS" Knock Sensor system activity. This will result in a net decrease in spark advance and thus poorer fuel economy. Using fuel of a higher octane than the vehicle was calibrated for WILL NOT increase fuel economy. Variations in how much fuel is added to the fuel tank during re-fueling can greatly affect calculated fuel economy. These effects decrease as the distance traveled and the number of tank fillups increase. Green Engine New vehicles have not yet had an opportunity for the engine to break in, (rings to seat ... ). A typical engine will take 3 to 5 thousand miles to break in and during this time period a gradual increase in fuel economy can be expected. Parasitic Loads Air conditioning and/or electrical loads, (headlights, heated backglass ... ) also result in lower fuel economy, (typically less than 1 MPG difference, each 10 AMPs takes approximately .4 MPG). Road Conditions Road surface condition impacts fuel economy. Gravel and/or pot holed roads decrease fuel economy. Hills (vs. level terrain) also negatively impact fuel economy. Even gradual unperceptible increases in elevation result in real measurable decreases in fuel economy. Similarly, driving in the rain or snow decreases fuel economy. Suspension Vehicle suspension misalignment can cause poor fuel economy. Check all four tires for abnormal and/or premature tire wear. New tires, tire rotation, and/or front end alignment may be required to correct fuel economy. Tires Performance tires and/or tires with larger "contact areas," (like 60 series aspect ratio), can cause as much as 3 MPG lower fuel economy when compared to hard "thin" tires. Find out if the tire size currently on the car is the same as original equipment. Replacement tires tailor than original equipment tires cause the odometer to read LESS THAN actual distance traveled. This will result in lower calculated fuel economy than actual fuel economy. Tire Pressure Harder tires, (more air pressure, or different tire compositions) result in better fuel economy. Do not exceed maximum pressure as labeled on the tire, typically 30-35 psi. The disadvantage of this is that the greater the tire pressure, the harsher the vehicle ride. Transmission On 4-Speed automatics, it is possible to drive the vehicle in 3rd gear rather than "overdrive" and not perceive it. Typically this condition occurs when the shift indicator, or the shift linkage/detent is misadjusted. Misadjusted shift linkage can also result in improper signals to the ECM, which can result in less spark advance, and results in a drop in fuel economy. Driving a vehicle in 3rd gear rather than overdrive at highway speeds typically results in a 3 to 5 MPG penalty. Torque Converter Clutch operation is essential for good fuel economy. A non-locking torque converter typically results in a 1 to 2 MPG penalty at highway speeds. Vehicle Weight Each 125 lbs. of additional weight results in a .3 MPG loss of fuel economy. Thus, additional passengers, luggage ... will decrease fuel economy. Vehicle Wind Resistance More wind "DRAG" means less fuel economy. Thus, hang-on luggage carders, cat toppers, open windows and/or open trunk... mean less fuel economy. (See "Driving Habits"). Capacity Specifications Fluid - Differential: Capacity Specifications Rear Axle Oil Pints 3.9 pt (US) Front Drive Axle 2.6 pt (US) Page 1238 from contacting these areas. Clean any fluid that may drip onto wheel cylinders or calipers to prevent corrosion. Always re-seal and wipe off brake fluid containers to prevent spills. Tools Required: J 39177 Valve Pressure Bleeding Tool (three required) Note: You can also use a modified J 35856 Valve Pressure Bleeding Tool providing you remove the dimple from it first. J 29567 Universal Brake Bleeder Adaptor (use for pressure bleed) J 29532 Diaphragm Type Brake Bleeder (brake fluid pressure tank for pressure bleed) TK 00000 Tech-1 Scan Tool TK 02650 RWAL/4WAL Cartridge Kit (include proper cable/adaptor), or 7000001 Mass Storage Cartridge Kit (include proper cable/adaptor) 3000003 Mass Storage Cartridge (include proper cable/adaptor) MANUAL BLEED PROCEDURE When a pressure bleeder is not available, use the (two person) manual bleed procedure. One person will push on the brake pedal while the other person will open and close the bleed valves. Important You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Begin by opening the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (Figure 2). 2. Attach the valve pressure bleeding tool J 39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (Figure 3). Tighten tool J 39177 only finger tight. Note: It is not necessary to attach bleeding tool J 39177 to the combination valve when using the manual bleed procedure. 3. Bleed each wheel in the following sequence: Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ROCKER ARM NUT TORQUE Valve Rocker Arm Nuts ....................................................................................................................... ................................................ 27 Nm (20 lb. ft.). Page 7846 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Page 6205 3. Clutch coil assembly (8). - Coil housing retaining ring (7) with J 6435. - Using a large screwdriver or small pry bar; pry the clutch coil away from the front head. If necessary, hand impact a blow to the screwdriver handle or pry bar to break the adhesive bond of the clutch coil to the front head. Clean Adhesive from the coil by scraping with a putty knife. - Remove any adhesive around the three locator hole areas of the front head and around the three clutch coil locator protrusions at the rear of the clutch coil housing. - Use a suitable solvent to clean the coil. Important After applying Loctite Depend, Loctite Trim and Detail Adhesive or equivalent to the coil, install all the clutch parts to the compressor. Allow 30 minutes for the adhesive to set. Install or Connect Tool Required: J 6435 External Snap Ring Pliers Adhesive Fill Guide 1. Adhesive to the clutch coil (8) - Place the clutch coil "face down" and apply the adhesive in a circular bead around the three coil locator protrusions. Page 3103 EGR Filter: Service and Repair EVRV Filter Replacement EVRV Filter Replacment REMOVAL AND INSTALLATION: 1. Grasp and pull the filter OFF with a rocking motion. 2. Push the new filter on making sure that the cut-out for the wires is properly aligned. With A-6 Compressor Compressor Clutch Bearing: Service and Repair With A-6 Compressor Remove or Disconnect Tools Required: J 6435 External Snap Ring Pliers J 8092 Driver Handle J 8433 Heavy Duty Pulley Puller J 9395 Pulley Puller Adapter J 9398-A Pulley Bearing Remover J 9481-A Pulley Bearing and Pulley Installer Page 7690 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 5673 Steering Gear: Service and Repair Nippon Seiko Recirculating Ball Gear Fig. 4 Checking Steering Gear Oil Level Ensure that oil level is up to level A, Fig. 4. If level is low, add GM Manual Steering Gear Lube 1052182 or equivalent. Cooling - Cold Start Fan Noise Higher Than Normal Fan Clutch: All Technical Service Bulletins Cooling - Cold Start Fan Noise Higher Than Normal Number: 92-118-6B Section: 6B Date: FEB. 1992 Corporate Bulletin No.: 166203 ASE No.: A8 Subject: COLD START FAN NOISE Model and Year: 1988-92 S/T TRUCKS WITH 4.3L ENGINES Owners of some 1988-1992 S/T vehicles equipped with a 4.3L engine (RPO LB4 or L35) and air conditioning (RPO C60) may experience higher than normal fan noise upon oold start up. This condition may be due to incorrect engagement of the fan clutch. The condition may be corrected by installing a revised fan clutch (P/N 15672779). Vehicles built after the following VIN Breakpoints have the new fan clutch installed in production: Plant VIN Moraine 1GNDT13Z3N2151684 Shreveport 1GCCS19Z3N8156864 Pontiac West 1GNCS18Z2N0125676 SERVICE PROCEDURE: Refer to section 6B1 "FAN/FAN CLUTCH REPLACEMENT" in the appropriate S/T Service Manual for removal and installation of the fan clutch. M/T - Clutch Pilot Bushing and Bearings Pilot Bearing: All Technical Service Bulletins M/T - Clutch Pilot Bushing and Bearings File In Section: 7 - Transmission Bulletin No.: 46-73-02 Date: October, 1994 INFORMATION Subject: Clutch Pilot Bushings and Bearings Models: 1988-95 Chevrolet and GMC Truck Light Duty Trucks with 4.3L, 5.0L, 5.7L, 6.2L, 6.5L, 7.4L Engines and Manual Transmission A worn or damaged clutch pilot bushing or bearing, located in the end of the crankshaft, can be the cause of various clutch and transmission concerns including: ^ Noise when the clutch pedal is depressed ^ Transmission noise ^ Clutch shudder on launch ^ Difficult shifting or excessive clash into reverse A worn clutch pilot bushing will not properly support the transmission input shaft. Without sufficient support, the front of the input shaft can move out of location resulting in transmission noise or clutch shudder on engagement. A damaged clutch pilot bushing or bearing may continue to turn the transmission input shaft when the clutch is released. This rotation can then cause difficult shifting or gear clash. Anytime a transmission or clutch is removed for repair, a new clutch pilot roller bearing should be installed. The end of the transmission input shaft that contacts the pilot roller bearing should also be inspected for damage. When installing the pilot roller bearing, the chamfer or lead-in to the I.D. should be installed facing the rear of the vehicle. This chamfer will help guide the input shaft into the roller bearing. This bearing is pre-lubed with a high temperature grease and does not require additional lubrication. The bearing listed below will fit all 1988-95 4.3L, 5.OL, 5.7L, 6.2L, 6.5L, and 7.4L light duty engines. Do not use a bronze clutch pilot bushing. Parts Information P/N Description Qty 14061685 Bearing, clutch Pilot 1 Parts are currently available from GMSPO. Page 4346 Axle Shaft Assembly: Description and Operation GMC Single Speed GMC single speed rear axle of 11,000 lbs. rated capacity This axle, Fig. 8, is a full floating type and enables removal of the axle shafts without removing the truck load or raising the rear axle. The drive pinion is straddle mounted and supported at the rear end by a straight roller bearing and at the front end by a double row ball bearing. Page 7383 Symbol Identification Page 6653 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 2739 Intake Air Temperature Sensor: Description and Operation Intake Air Temperature Sensor PURPOSE The Intake Air Temperature (IAT) sensor is a thermistor and converts the resistance of the sensor to degrees. IAT is used by the control module to adjust fuel delivery and spark timing according to oncoming air density. OPERATION The control module applies a voltage (4-6 volts) signal to the IAT sensor through a resistor within the PCM and measures the voltage. By measuring the voltage, the PCM can determine IAT. Low intake air temperature produces high resistance (100,000 ohms at -40°C/-40°F) and high voltage. High intake air temperature produces a low resistance (70 ohms at 130°C/266°F) and low voltage. Page 1346 Convenience Center (with Digital Cluster) Page 8298 Figure 7 Figure 8 Figure 9 Figure 10 Page 4719 Wheel Cylinder: Service and Repair Rebuild For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Fig. 8 Disassembled View Of Wheel Cylinder (typical) 1. Remove boots, pistons, springs and cups from the wheel cylinder. 2. Clean all parts with brake fluid. 3. Inspect cylinder bore. A scored bore may be honed as long as the diameter is not increased by more than 0.127 mm (0.005 inch). Replace worn or damaged parts as necessary. 4. Ensure hands are clean before proceeding with assembly. Lubricate cylinder wall and rubber cups with brake fluid, then install springs, cups, pistons and boots in housing. 5. Install wheel cylinder. Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks utilize a warning light on the instrument panel in place of the conventional dash indicating gauge to warn the driver when the oil pressure is dangerously low. The warning light is wired in series with the ignition switch and the engine unit-which is an oil pressure switch. The oil pressure switch contains a diaphragm and a set of contacts. When the ignition switch is turned on, the warning light circuit is energized and the circuit is completed through the closed contacts in the pressure switch. When the engine is started, build-up of oil pressure compresses the diaphragm, opening the contacts, thereby breaking the circuit causing the light to go out. Page 5615 TURBO 1. Remove air cleaner duct, upper fan shroud, serpentine belt, fan and pulley. 2. Using power steering pump pulley remover tool No. J 25034-B, remove pulley. 3. Ensure pilot bolt bottoms in pump shaft by turning nut to top of pilot bolt. Hold pilot bolt and turn nut counterclockwise. 4. Raise and support vehicle. 5. Remove left wheel assembly and wheelhouse panel. 6. Remove attaching bolt from hose bracket. Allow fluid to drain into a suitable container, Fig. 23. 7. Disconnect return and pressure hoses from power steering pump, then cap hoses. 8. Remove attaching bolts from rear bracket at alternator. 9. Lower vehicle. 10. Remove pump and attaching nuts from rear bracket. 11. Reverse procedure to install. Disassembly Fig. 1 Exploded View Of TC Series Power Steering Pump Fig. 2 Clip and reservoir removal Page 633 Electronic Spark Control (ESC) Circuit Circuit Description: The Code 43 circuit consists of two knock sensors with one wire that goes directly to the ECM. There are two Code 43 checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 4.4 volts. If voltage is either too high or too low for 2 or more seconds, Code 43 will set. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3800 rpm, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, Code 43 will set. Diagnostic Aids: The ECM applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the ECM, is able to read this signal as knock and incrementally retard spark. If the ESC system checks OK, but detonation is the complaint, See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Page 3013 Chart 6 Vehicle Speed Sensor Test Page 4224 Disclaimer Page 3865 Page 1645 Engine Broadcast Code Information (last three digits of the engine I.D. number located In front of the right cylinder head at deck height): WARRANTY INFORMATION Condition I - For vehicles repaired by changing balance shaft drive gears: Condition II - For vehicles repaired by installing a Goodwrench engine: Important: Applicable miscellaneous items, such as engine oil and engine coolant, should be added to the above part allowance amount and included in the Net Amount (DMN) column of the claim. PARTS INFORMATION Content: Cylinder and case, cylinder head assembly, crankshaft, crankshaft main and rod bearings, piston and connecting rod assembly, T Truck/L Van oil pan and screen assembly, camshaft, valve lifters, push rods, camshaft chain and sprockets, balance shaft, balance shaft drive gears, valve lifter retainer, front cover and pointer, valve rocker cover, oil fill cap, harmonic balancer. Additional Parts Required to Dress-Out the Goodwrench Engine: (Quantity: 1 each, except as noted) Page 8301 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 2896 ECM QDR Check Procedure Page 1003 Disclaimer Hydraulic System Bleeding Brake Bleeding: Service and Repair Hydraulic System Bleeding Manual Bleeding 1. If vehicle is equipped with power brakes, remove vacuum reserve by applying brakes several times with engine off. 2. Fill master cylinder reservoirs with suitable brake fluid. Be sure to always keep master cylinder reservoirs at least half full during entire bleeding procedure. 3. If master cylinder is suspected to have air in the bore, it must be bled first, as follows: a. Disconnect forward brake pipe connection at master cylinder. b. Allow brake fluid to fill master cylinder bore until it begins to flow from forward pipe connector port. c. Connect and tighten forward brake pipe at master cylinder. d. Depress brake pedal slowly one time and hold, then loosen forward brake pipe connection at master cylinder to purge air from bore. Tighten connection, then release brake pedal slowly. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged from bore. e. Bleed rear bore of master cylinder as front bore was bled. 4. Bleed right rear brake as follows: a. Depress brake pedal slowly one time and hold. b. Loosen bleeder valve to purge air from brake, then tighten bleeder valve and slowly release pedal. c. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged. 5. Bleed left rear, right front, and left front brakes, in that order, using same method as for right rear brake. 6. Check brake operation and ensure pedal is firm. Also check master cylinder fluid level and add fluid as necessary. 7. Turn off brake warning light by applying moderate pressure to brake pedal several times. 8. Road test vehicle. Fig. 1 Installing Pressure Bleeder Adapter Pressure Bleeding 1. Loosen, then slightly retighten bleeder valves at all four wheels. Repair any broken, stripped or frozen valves at this time. 2. Using a diaphragm type pressure bleeder, install suitable bleeder adapter to master cylinder, Fig. 1. 3. Charge bleeder ball to 20-25 psi, then depress and hold valve stem on combination valve. 4. Connect pressure bleeder line to adapter. 5. Open line valve on pressure bleeder, then depress bleed-off valve on adapter until a small amount of brake fluid is released. 6. Raise and support vehicle. 7. Bleed right rear, left rear, right front and left front brakes, in that order. 8. Place transparent tube over bleeder valve, then allow tube to hang down into transparent container. Ensure end of tube is submerged in clean brake fluid. 9. Open bleeder valve 1/2 to 3/4 turn and allow fluid to flow into container until all air is purged from line. Flushing Hydraulic System If brake fluid is old, rusty or contaminated, or whenever new parts are installed in the hydraulic system, the system must be flushed. Bleed brakes, allowing at least one quart of clean brake fluid to pass through system. Any rubber parts in hydraulic system which were exposed to contaminated fluid must be replaced. Page 5234 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 8666 Front Door Trim Panel Components NOTE: Images shown are for manual windows, power windows are similar. Tool Required: J-21104 Trim Pad Remover. REMOVE OR DISCONNECT 1. Door pillar molding. 2. Armrest. 3. Power window switch. 4. Trim panel. Pry the fasteners from their seats using J-21104. INSTALL OR CONNECT 1. Trim panel to the door. 2. Armrest. 3. Power window switch. 4. Door pillar molding. Door Inner Panel Water Deflector Replacement Page 652 The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/OXYGEN SENSOR TESTING. Page 7425 Figure 7 Figure 8 Figure 9 Figure 10 Page 7280 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Body - Vehicle Glass Distortion Information Windshield: All Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 3144 Positive Crankcase Ventilation Valve: Service and Repair Inspection The crankcase ventilation system should be checked every 30,000 miles and also during regular engine tune-ups. If the crankcase ventilation system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the crankcase ventilation valve or air cleaner is replaced. When a periodic inspection indicates the crankcase ventilation is not functioning properly, it should be serviced by replacement only. Page 5536 Disclaimer Page 7605 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 5204 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 7068 M - Miracryl(R) Super Max(R) FLEXIBLE FINISHES When spraying flexible plastic parts, use the following recommendations: Elastifier additive 521-111 for Vinyl application when using Glasurit(R) 54 and 21 lines. 891 Flex Agent for Vinyl Application when using Alphacryl, Miracryl, Diamont 88(R), and Supreme Gold. DF-25 for Vinyl application when using Diamont Solo(R). NOTE: When using a basecoat/clearcoat system only use the flex agent in the clearcoat application. STONE CHIP PROTECTOR Glassohyd(TM) 1109-1240/6 Stone Chip Protector is a waterborne material which uses a durable, flexible plastic dispersion as its bonding media. This product is versatile in application and may be easily applied by spray, brush, or roller. When Glassohyd(TM) is completely cured, the material is resistant to water, gasoline, and oil. Glassohyd(TM) has excellent stone impact and corrosion resistance. Glassohyd(TM) Stone Chip Protector can be topcoated directly with 21-line or 54/94-line colors. DuPont refinished paints are available in: - L-Lucite(R) - Acrylic Lacquer - A-Centari(R) - Acrylic Enamel - J-Cronar(R) - Polyoxithane Enamel - K-ChromabaseTM - 350S - Flexlar(R) - Flexible Additive - 310S - Black - 1-2-3 Vinyl Lacquer - 330S - White - 1-2-3 Vinyl Lacquer - V-Lucite Vinyl Important Vinyl resin must be added to the base color when painting interior components. DuPont vinyl resin 304S (instrument panel). DuPont vinyl resin 305S (all remaining interior parts except seats). DuPont vinyl resin 306S (seats and vinyl roofs). When ordering DuPont paint, use "L", "A", "J", "K", or "V" with the appropriate DuPont Code. PPG (Ditzler) refinish paints are available in: - DDL - Duracryl(R) - Acrylic Lacquer or Acrylic Basecoat/Clearcoat - DBU - Deltron(R) - Basecoat/Clearcoat - DAR - Delstar(R) - Acrylic Enamel - DAU - Deltron(R) - Acrylic Urethane - UCV - Vinyl Colors - DX-369 - Flexative(R) - Flexible Finishes - DX-54 - Roadguard(R) - Road Abrasion Protection When ordering PPG (Ditzler) paint, use "DDL", "DBU", "DAR", "DAU", "UCV", "DX-54", or "DX-369" with appropriate Ditzler code. Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: Customer Interest Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 8577 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Distributor Operation Distributor: Description and Operation Distributor Operation EST Distributors With Separate Coil (Typical) Page 3171 cable to operate freely SERVICE PROCEDURE To correct vehicles encountering the cable slipping out of the pulley replacement of the accelerator cable is necessary. Refer to the appropriate 1992 Light Truck Service Manual, Fuel and Emissions section, page 4- 72 for proper accelerator cable removal and installation. NOTE: Before installation, inspect the cable for kinks, curls or bends, especially at the, TBI end. SERVICE PARTS INFORMATION Part Number Description Application 15693481 Cable Asm-Accel S/T 15957337 Cable Asm-Accel M/L 15631395 Cable Asm-Accel G Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation - J5330 Use applicable labor time guide for labor hours. Page 6997 What if I input the VIN incorrectly? If an incorrect VIN is entered into the system (meaning that the system does not recognize the VIN or that the VIN has been entered incorrectly) the system will return an error message. If I am an authorized user for the KeyCode application, can I access the application from home? Yes. What if I suspect key code misuse? Your dealership should communicate the proper procedures for requesting key codes. Any suspicious activity either within the dealership or externally should be reported to Dealer Systems Support at 1-800-265-0573 or GM of Canada Key Code Inquiry Desk at 1-905-644-4892. Whose key codes can I access through the system? At this time the following Canadian vehicle codes are available through the system: Chevrolet, Cadillac, Buick, Pontiac, GMC, HUMMER (H2 and H3 only), Oldsmobile, Saturn, Saab and Isuzu (up to 2002 model year) for a maximum of 17 model years. What should I do if I enter a valid VIN and the system does not produce any key code information? Occasionally, the KeyCode Look Up application may not produce a key code for a valid VIN. This may be the result of new vehicle information not yet available. In addition, older vehicle information may have been sent to an archive status. If you do not receive a key code returned for valid VIN, you should contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. How do I access KeyCodes if the KeyCode Look-up system is down? If the KeyCode Look-up system is temporarily unavailable, you can contact the original selling dealer who may have it on file or contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the customer is dealing with an emergency lock-out situation, you need to have the customer contact Roadside assistance, OnStar if subscribed, or 911. What should I do if the KeyCode from the look-up system does not work on the vehicle? On occasion a dealer may encounter a KeyCode that will not work on the vehicle in question. In cases where the KeyCode won't work you will need to verify with the manufacturer of the cutting equipment that the key has been cut correctly. If the key has been cut correctly you may be able to verify the proper KeyCode was given through the original selling dealer. When unable to verify the KeyCode through the original selling dealer contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the key has been cut correctly and the code given does not work, the lock cylinder may have been changed. In these situations following the proper SI document for recoding a key or replacing the lock cylinder may be necessary. How long do I have to keep KeyCode Records? Dealership KeyCode documentation must be retained for two years. Can I get a KeyCode changed in the Look-Up system? Yes, KeyCodes can be changed in the Look-Up system if a lock cylinder has been changed. Contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. What information do I need before I can provide a driver of a company fleet vehicle Keys or KeyCode information? The dealership should have a copy of the individual's driver's license, proof of employment and registration. If there is any question as to the customer's employment by the fleet company, the dealer should attempt to contact the fleet company for verification. If there is not enough information to determine ownership and employment, this information should not be provided. How do I document a request from an Independent Repair facility for a KeyCode or Key? The independent must provide a copy of their driver's license, proof of employment and signed copy of the repair order for that repair facility. The repair order must include customer's name, address, VIN, city, province and license plate number. Copies of this information must be included in your dealer KeyCode file. Page 6431 Page 1300 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 6846 Front Door Panel: Service and Repair Door Trim Panel Replacement Front Door Trim Panel Page 8538 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 334 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 2311 INSPECT - Be sure the installed hose(s) do not sag or rub against other components. Adjust or support the hose as necessary to correct. - Operate the engine and check the hose installation for leaks. - Tighten the hose clamp screw a bit at a time, if necessary, to stop a leak. - Check the coolant level after the engine has been warmed up and allowed to cool. Add coolant as required. Page 6589 Symbol Identification Page 4630 ^ Right rear ^ Left rear ^ Right front ^ Left front Note: Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. Note: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 4. Slowly apply the brake pedal one time and hold. 5. Loosen the bleeder valve to purge the air from the wheel cylinder/caliper. 6. Tighten the bleeder valve and slowly release the pedal. 7. Wait 15 seconds. 8. Be sure to check the master cylinder fluid level after 4-5 strokes to avoid running dry. 9. Repeat steps 4 through 8, until all air is purged from the wheel cylinder/caliper. Note: It may be necessary to repeat this sequence as many as 15 to 20 times per wheel. 10. Fill the master cylinder to the proper level and replace lid. 11. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs.in.). 12. Remove the valve pressure bleeding tools J 39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 13. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. Important DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 14. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. Important DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 15. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs. in.). 16. Fill the master cylinder to the proper level with brake fluid. 17. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. Important MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 18. Repeat the entire brake bleed procedure if necessary. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation: H0700 Labor Time: See applicable labor time guide Note: When performing the 4WAL brake system bleeding procedure. the ignition switch must be in the "OFF" position or false diagnostic trouble codes could be set to memory. If trouble codes are set, refer to Section 5E1 "Clearing Diagnostic Trouble Codes" in the 1993 Service Manual. PRESSURE BLEED PROCEDURE Page 5578 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Page 6147 Removing Pulley Rotor And Bearing Assembly 3. Install pulley rotor and bearing puller guide J 33023-A to the front head and install J 33020 pulley rotor and bearing puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots to engage the puller tangs with the segments between the slots in the rotor. 4. Hold the J 33020 puller in place arid tighten the puller screw against the puller guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal the rotor hub must be properly supported. Pulley Rotor Bearing Removal Remove the forcing screw from J 33020 puller and, with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks as shown in the illustration. 6. Drive the bearing out of the rotor hub with rotor bearing remover J 9398-A and J 29886 universal handle. Page 8114 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 56 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Fastener Tightening Specifications Wheel Fastener: Specifications Wheel Lug Nuts Aluminium wheels 90 ft.lb Steel wheels 73 ft.lb Page 4450 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Left Side Knock Sensor Engine Wiring, LH Side Page 7720 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 1877 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Page 7172 Figure 7 Figure 8 Figure 9 Figure 10 Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Torque Specifications Crankshaft: Specifications Main Bearing Cap Bolts 80 ft.lb Page 5237 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 3909 1 Gallon 12346144 55 Gallon 12346145 In Canada 1 Liter 10952622 4 Liter 10952623 200 Liter 10952624 The 1995 Automatic Transmission/Transaxle fluid change intervals are the following: (1994 and prior should use the schedules as written in the Owner's Manual.) If the vehicle is mainly driven under one or more of these conditions: In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. Uses such as found in taxi, police car or delivery service. Change the fluid and filter every 50,000 miles (63,000 km). If the vehicle is not used mainly under any of these conditions, the fluid and filter do not require periodic changing for vehicles under 8,600 GVWR. Vehicles over 8,600 GVWR change the fluid and filter every 50,000 miles (83,000 km) regardless of driving conditions. Aluminum Wheels - Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Page 8528 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 4548 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 4563 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 4020 1. On vehicles equipped cruise control, remove cruise control rod. 2. On all models, disconnect TV cable from throttle assembly, then loosen locknut on pump rod and shorten several turns. 3. Turn lever assembly to full throttle stop and hold in this position. 4. Adjust pump rod until injection pump lever contacts full throttle stop. 5. Release lever assembly and tighten pump rod locknut, then remove pump rod from lever assembly. 6. Connect TV cable to throttle assembly, then depress and hold metal readjusting tab. Move slider back through fitting in direction away from lever assembly until slider stops against fitting, Fig. 7. 7. Release readjust tab, then rotate lever assembly to full throttle stop and release the lever. 8. Connect pump rod and, if equipped, the cruise control throttle rod. 9. On vehicles equipped with cruise control, adjust servo throttle rod to minimum slack position. Install clip into servo ball in first free hole closest to the bell crank. Page 6140 3. Pulley (6) and bearing (5) to shaft (38) with J 8092 and J 9481-A. 4. Retainer ring (4) to pulley (6) and bearing (5). 5. Pulley retainer ring (3) with J 6435. 6. Clutch plate and hub assembly (2). Clutch Coil Assembly Remove or Disconnect Tool Required: J 6435 External Snap Ring Pliers 1. Clutch plate and hub assembly (2). 2. Pulley (6). Locations Steering Column Locations Power Steering Pressure Switch Wiring Page 7253 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 5505 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Locations Horn Relay Installation Page 4935 Figure 7 Figure 8 Figure 9 Figure 10 A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 8085 Transmission Shift Position Indicator Lamp: Locations Speed Sensor & Backup Lamp Switch Locations. LH Side Rear Of Transfer Case Applicable to: 1991 Blazer & Jimmy & 1992 4WD Models Page 8407 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 8259 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 2767 Electronic Control Module Page 5192 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 7053 Door edge guards Bumper filler panel, Frt./Rr. Front side marker lamps *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary G VANS Wiper arms Cowl vent grille Grille and headlamp bezels Front bumper filler panel Antenna Side view mirrors Side marker lamps Tail lamps Door edge guards Wheel opening moldings *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary Swing out windows/seals WARRANTY INFORMATION For vehicles repaired under warranty. and for customer satisfaction. use: Labor Op (Labor Operations include mix time) A6100 Refinish the entire exterior body surface ABOVE THE BODY SIDE MOLDING AND INSERT COLOR on two tone vehicles if equipped. A6101 Refinish the entire exterior body surface INSERT COLOR only. A61O2 Refinish the PICKUP BOX LOAD FLOOR AND INNER FENDERS when applicable. A61O3 On units with an insert color, included is the entire exterior body surface ABOVE THE BREAKLINE. (If the insert color and the entire body surface above the break-line requires refinishing, use A6100). Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Page 5389 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 1156 f. TO INSURE AN ACCURATE CHARGE AMOUNT, IT IS IMPORTANT TO CLEAR THE ACR4 OF ANY REMAINING REFRIGERANT. Close the high side coupler valve and remove the high side hose from the vehicle. Then, open both the high and low side valves on the ACR4. After the pressures on both gages are at low side pressure, close the low side coupler valve. See Step G below, then remove the low side hose from the vehicle. Shut off the engine. Install the service port caps on the new fittings. These serve as a seal and can prevent system leaks. g. In the unlikely event that the low side fitting leaks when the coupler is removed, use the following procedure: 1. Immediately reinstall the coupler on the fitting. 2. Find the valve core remover J 34611-A. 3. Remove the coupler. 4. Use the double-ended valve core remover to turn the valve core pin counter-clockwise until the leak stops. 5. Install the cap. If the leak was substantial or continued for an extended period of time, it is highly recommended to evacuate and recharge the system to insure proper performance. If there is any question, the system can be rechecked by repeating Step F. h. Leak test any new port fittings, adapters, or valves that were installed, and any joints that were opened or repaired during the retrofit process, using tool J 39400. 6. Install the Retrofit Label The retrofit label (P/N 21030857, roll of 250) has been developed following SAF specifications to insure a smooth transition from R-12 to R-134a, and to insure a professional approach to the retrofit and a quality repair. Following the instructions in this bulletin will insure that the retrofit meets the SAE standards. Fill in the new label using a typewriter or a ball-point pen (see Figure 6). Select a location for the label that will be easily visible. Some suggested areas are the radiator support panel, an area near the existing R-12 charge label, or a flat surface near the high or low side service ports. The area selected should be a clean, underhood, painted sheet metal surface, and should be degreased and wiped down with a non-petroleum based cleaner. Do not install the label on a rubber surface. Apply the label, then apply the clear overlay to the label. Do not remove, cover, or render unreadable the existing R-12 charge label. DO cover the R-12 refrigerant charge amount on the existing label with an indelible, preferably black, marker. Platform Details Page 405 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 3910 Fluid - A/T: Technical Service Bulletins A/T - New Trans Fluid, Dexron IIE Number: 92-26-7A Section: 7A Date: OCT. 1991 Corporate Bulletin No.: 177125 ASE No.: A2 Subject: DEXRON-IIE AUTOMATIC TRANSMISSION/TRANSAXLE FLUID Model and Year: 1976-92 ALL TRUCKS WITH AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: SUBJECT: All Automatic Transmissions DEXRON-IIE Automatic Transmission/Transaxle Fluid TRANSMISSION MODELS: VEHICLE APPLICATIONS: All All HYDRA-MATIC Automatic Transmissions/Transaxles Bulletin Covers: General Motors Corporation has developed a new service fill automatic transmission/transaxle fluid which is designated DEXRON-IIE. This fluid is the preferred fluid for all HYDRA-MATIC automatic transmission/transaxles and will eventually replace DEXRON II. DEXRON-IIE is acceptable for use wherever DEXRON II was previously specified. DEXRON II is acceptable for use when DEXRON-IIE is not available. DEXRON-IIE can be used in both electronically and hydraulically controlled transmissions/transaxles. DEXRON-IIE Advantages: ^ Has better anti-foaming characteristics. ^ Improved low temperature flow characteristics (low temperature viscosity) and improved high temperature oxidation stability. ^ DEXRON-IIE and DEXRON II can be mixed in any ratio. No draining or flushing of system is required. ^ DEXRON-IIE is back serviceable to 1949 for all General Motors automatic transmission/transaxles. ^ No change in transmission/transaxle calibration or reduction in transmission/transaxle durability will occur as a result of using DEXRON-IIE. Service Parts Information: PART NUMBER DESCRIPTION 12345881 1 quart container 12345882 1 gallon container 12345883 55 gallon drum Parts are currently available from GMSPO. Page 4711 - Place the pointed tip of the pliers onto the brake shoe lining surface directly across from the spring (if the shoes are to be reused, place the tip into a rivet hole or place a thin sheet of wood between the linings and pointed tip). - Squeeze the pliers and lift the return spring from the hole. - Release the pliers slowly and remove the other end of the spring. Installation Use the same technique for installing the spring as was used for removing it. - If a rivet hole is not available, place a thin sheet of wood between the lining and pointed end of the tool. - A pair of needle nosed pliers may be helpful for guiding the end of the return spring into the hole. WARNING: Do not attempt to help the spring into the hole with your fingers. Should the return spring slip off the tool it could seriously lacerate your hand. Page 5240 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Description and Operation Fuel Economy Warning System: Description and Operation This system actually monitors the engine vacuum just like the vacuum gauge, but registers only low vacuum readings. The light on the instrument panel warns the vehicle operator when engine manifold vacuum drops below the economical limit. Switch operation is similar to that of the oil pressure indicating light, except that the switch opens when vacuum pressure, rather than oil pressure, is applied. Fuel - Removal And Installation of CPI Fuel Line Clips Fuel Supply Line: All Technical Service Bulletins Fuel - Removal And Installation of CPI Fuel Line Clips BULLETIN NO: 93-6C-46 SECTION: 6C NUMBER: 3 CORPORATE REFERENCE NO: 266306 DATE: February, 1993 SUBJECT: INFORMATION ON INSTALLATION OF CPI FUEL LINE CLIPS MODELS: 1992-93 S/T AND M/L MODELS WITH 4.3L ENGINES (RPO L35) Improper installation of the fuel line clips which hold the fuel inlet and outlet tubes to the Central Port Fuel Injection (CPI) unit may result in an internal CPI fuel leak. A fuel leak may cause driveability problems or in extreme cases, hydrolock. Proper Removal and Installation of Fuel Line Clips: Removal Using needle nose pliers, firmly grasp the fuel fitting clip as shown in Figure 1 and pull the clip straight back from the fuel meter body. It may be necessary to lift the opposite side of the clip with a screwdriver. Discard the clip. Installation Always use a new clip and 0-rings (P/N 17112702). Using your fingers as shown in Figure 2, slide the clip over the fuel meter body making sure that the clip properly engages the slots in the fuel inlet and outlet tubes and that the clip is properly positioned over the fuel meter body on both the top and bottom sides. The clip will be properly positioned when the flanges on the fuel meter body protrude from the clip and the clip snaps in place. Important Do not install the clip from the bottom-up position, the clip will not properly retain the fuel lines. Install the clip from the top-down position as shown in Figure 2. Secondly, it is important to note that the fuel lines MUST be in the correct inlet/outlet openings (The lines will fit either opening). Lastly, the fuel lines MUST be correctly seated into the TB body to allow for proper installation of the clips. Page 4319 Fig. 9 Pinion depth gauge installation PINION DEPTH, ADJUST If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION, INSTALL 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. Page 3371 Use applicable labor time guide for labor hours. Page 1684 Connecting Rod Bearing: Service and Repair Main bearings are available in standard size and undersizes of .001, .002, .009, .010 and .020 inch. Connecting rod bearings are available in standard size and .001 and .002 inch undersize for use with new and used standard size crankshafts and .010 and .020 inch undersize for use with reconditioned crankshafts. Page 6347 - Apply rubber lubricant to the inside diameter of hose ends, If desired. - Slip a new hose clamp over one end of the hose and push the hose onto the heater pipe with a twisting motion. - Repeat the hose and clamp installation procedure at the other end of the hose. - Tighten clamp screw to 1.7 Nm (15 in. lb.). 4. Engine coolant. - Use the coolant drained earlier only if it is uncontaminated. Discard contaminated coolant and add fresh 50/50 coolant and water mixture. Inspect - Be sure the installed hose(s) do not sag or rub against other components. Adjust or support the hose as necessary to correct. - Operate the engine and check the hose installation for leaks. - Tighten the hose clamp screw a bit at a time, if necessary, to stop a leak. - Check the coolant level after the engine has been warmed up and allowed to cool. Add coolant as required. Page 6422 - J 41265 Thread cleaning wire brush - J 41266 Low side port thread restorer - J 41267 High side port thread restorer - J 39037 High side octagon socket - J 41256 Low side octagon socket New low profile, quick connect couplers, J 39500-20A (High side), and J 39500-24A (Low side), have been released as essential tools, to attach to the ACR4 (see Figure 3). These are much smaller couplers than the existing ones, and will allow attachment to the port fittings in much tighter quarters. Page 2774 Diagnostic Circuit Circuit Description The diagnostic circuit check is an organized approach to identifying a problem created by an electronic engine control system malfunction. It must be the starting point for any driveability complaint diagnosis, because it directs the service technician to the next logical step in diagnosing the complaint. Understanding the chart and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of good parts. Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. This step is a check for the proper operation of the "Service Engine Soon" light. The "SES" light should be "ON" steady. 2. No "SES" light at this point indicates that there is a problem with the "SES" light circuit or the control module control of that circuit. 3. This test checks the ability of the control module to control the "SES" light. With the diagnostic terminal grounded, the "SES" light should flash a Code 12 three times, followed by any trouble code stored in memory. A PROM error may result in the inability to flash Code 12. 4. Most of the diagnostic charts use a Tech 1 to aid diagnosis, therefore, serial data must be available. If a PROM error is present, the control module may have been able to flash Code 12 or 51, but not transmit serial data. 5. Although the control module is powered up, a "Cranks But Will Not Run" symptom could exist because of an control module or system problem. 6. This step will isolate if the customer complaint is a "SES" light or a driveability problem with no "SES" light. See: Testing and Inspection/Diagnostic Trouble Code Descriptions for a list of valid codes. An invalid code may be the result of a faulty "Scan" tool, PROM or control module. 7. Comparison of actual control system data with the typical valves is a quick check to determine if any parameter is not within limits. Keep in mind that a base engine problem (i.e., advanced cam timing) may substantially alter sensor values. 8. If the actual data is not within the typical values established, refer to individual component tests. Page 5022 Neutral Safety Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Drivetrain - Recommended Axle Lubricant Fluid - Differential: Technical Service Bulletins Drivetrain - Recommended Axle Lubricant File In Section: 0 - General Information Bulletin No.: 76-02-02A Date: October, 1998 INFORMATION Subject: Recommended Axle Lubricant Models: 1999 and Prior Rear Wheel Drive Passenger Cars, Light and Medium Duty Trucks, and Four Wheel Drive Vehicles This bulletin is being revised to add the 1998 and 1999 Model Years and add Vehicle Line and Recommended Axle Lubricant Information. Please discard Corporate Bulletin Number 76-02-02 (Section 0 - General Information). The following tables provide the latest information on recommended axle lubricant. Cooling System - Coolant Recycling Information Coolant: Technical Service Bulletins Cooling System - Coolant Recycling Information Bulletin No.: 00-06-02-006D Date: August 15, 2006 INFORMATION Subject: Engine Coolant Recycling and Warranty Information Models: 2007 and Prior GM Passenger Cars and Trucks (Including Saturn) 2007 and Prior HUMMER Vehicles 2005-2007 Saab 9-7X Attention: Please address this bulletin to the Warranty Claims Administrator and the Service Manager. Supercede: This bulletin is being revised to adjust the title and Include Warranty Information. Please discard Corporate Bulletin Number 00-06-02-006C (Section 06 - Engine/Propulsion System). Coolant Reimbursement Policy General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words: if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of GM Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Licensed Approved DEX-COOL(R) Providers Important: USE OF NON-APPROVED VIRGIN OR RECYCLED DEX-COOL(R) OR DEVIATIONS IN THE FORM OF ALTERNATE CHEMICALS OR ALTERATION OF EQUIPMENT, WILL VOID THE GM ENDORSEMENT, MAY DEGRADE COOLANT SYSTEM INTEGRITY AND PLACE THE COOLING SYSTEM WARRANTY UNDER JEOPARDY. Shown in Table 1 are the only current licensed and approved providers of DEX-COOL(R). Products that are advertised as "COMPATIBLE" or "RECOMMENDED" for use with DEX-COOL(R) have not been tested or approved by General Motors. Non-approved coolants may degrade the Page 8297 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 2021 Engine Broadcast Code Information (last three digits of the engine I.D. number located In front of the right cylinder head at deck height): WARRANTY INFORMATION Condition I - For vehicles repaired by changing balance shaft drive gears: Condition II - For vehicles repaired by installing a Goodwrench engine: Important: Applicable miscellaneous items, such as engine oil and engine coolant, should be added to the above part allowance amount and included in the Net Amount (DMN) column of the claim. PARTS INFORMATION Content: Cylinder and case, cylinder head assembly, crankshaft, crankshaft main and rod bearings, piston and connecting rod assembly, T Truck/L Van oil pan and screen assembly, camshaft, valve lifters, push rods, camshaft chain and sprockets, balance shaft, balance shaft drive gears, valve lifter retainer, front cover and pointer, valve rocker cover, oil fill cap, harmonic balancer. Additional Parts Required to Dress-Out the Goodwrench Engine: (Quantity: 1 each, except as noted) Air Inlet Valve Assembly Replacement Air Door Actuator / Motor: Service and Repair Air Inlet Valve Assembly Replacement Plenum Air Inlet Valve Assembly REMOVE OR DISCONNECT 1. Windshield wiper arms. 2. Cowl vent grille. 3. Bolt (62). 4. Link (61) from the actuator (58). 5. Bolts (60). 6. Valve assembly (59). INSTALL OR CONNECT 1. Valve assembly (59). 2. Bolts (60). - Tighten bolts (60) to 2 Nm (18 in. lb.). 3. Link (61) to the actuator (58). 4. Bolt (62). - Tighten bolt (62) to 2 Nm (18 in. lb.). 5. Cowl vent grille. 6. Windshield wiper arms. Page 3079 Voltage Signal: Description and Operation Generator Over Voltage Signal PURPOSE Inform the control module that there is a basic generator over voltage problem. OPERATION PCM/ECM If voltage is greater than 19.5 volts for 2 seconds at PCM terminal "E16" (ECM is "C16"), the control module sets Diagnostic Trouble Code 53, the automatic transmission pressure control solenoid is turned "OFF", the automatic transmission shifts immediately to third gear, and TCC operation is inhibited. (the setting of additional DTC's may result.) VCM If voltage is greater than 17.1 volts at VCM terminal "GR2" sets Diagnostic Fault Code P1632. For 2 seconds after the fault is detected, the VCM will disengage its outputs. This may result in additional DTC's being set. Side Marker Lamp, LH Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Page 7585 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 7286 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Tools - Adjuster Locknut Wrench Steering Gear: Technical Service Bulletins Tools - Adjuster Locknut Wrench File In Section: 3 - Steering/Suspension Bulletin No.: 83-32-10 Date: November, 1998 INFORMATION Subject: Essential Tool J 43435 Adjuster Locknut Wrench Models: 1990-99 Passenger Cars and Trucks with Integral Power Steering A new essential tool, J 43435 Adjuster Locknut Wrench, has been sent to all GM Dealers. This tool should be used on all Integral power steering gears, both past and current models. The following procedure should be used In place of existing Service Manual procedures for Coupling Shield and Locknut Removal and Replacement. The correct adjustment procedure and use of the essential tools are critical to restore the vehicle "On Center" feel (See Figure 1). Important: Coupling shield retainer and locknut assembly replacement procedures require the following special tools: J 42882 Adjuster Nut Wrench J 43435 Adjuster Locknut Wrench Page 7207 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 8223 Hazard Flashers Without Digital Cluster Page 6189 Compressor Clutch Bearing: Service and Repair With HR100T/HR110T Compressor 4 Pole Clutch V-GROOVE TYPE - 4 POLE CLUTCH Remove or Disconnect 1. Remove the Clutch Plate and Hub assembly. 2. Remove Rotor and Bearing assembly retaining ring, using Snap Ring Pliers J 6083 (Fig. 9). Mark the location of the clutch coil terminals. If only the Clutch Rotor and/or Rotor Bearing are to be replaced, bend the screw head washer away from the pulley rim and remove the six (6) mounting screws before proceeding with Step 3. Discard the mounting screws. 3. Install Rotor and Bearing Puller J 25031 down into the rotor until the Puller arms engage the recessed edge of the rotor hub. Hold the Puller and arms in place and tighten the Puller screw against the Puller Guide to remove the Clutch Rotor and Bearing assembly (Fig. 10), being careful not to drop the Puller Guide. 4. If the pulley rim mounting screws were removed in Step 2, only the Clutch Rotor and Bearing assembly will be removed for replacement. The Clutch Coil and Housing assembly is pressed onto the Front Head of the compressor with a press fit and will not be removed unless the pulley rim mounting screws are left securely in place and the pulley rim pulls the Coil and Housing assembly off with the total Clutch Rotor and Pulley Rim Assembly. Page 4801 Brake Master Cylinder: Fundamentals and Basics Bench Bleeding Notes BENCH BLEEDING Why A master-cylinder will develop little or no pressure if air is trapped in cylinder bore. Normal brake bleeding will not remove air trapped within the master-cylinder. How Clamp the master-cylinder securely in a vice. It is usually best to clamp the side of the vice onto the flat surface that is used to secure the master-cylinder to the brake booster. There are two basic methods for bleeding master-cylinder, one utilizes stroking the master-cylinder to expel air from the cylinder bore while the other utilizes a large syringe to backflush fluid from the outlet ports to the reservoir. Stroking Fill the master-cylinder with clean brake fluid. - The brake line fittings on the master-cylinder should be capped or plugged. NOTE: Special "bench bleeding" plastic fittings are available which allow for recirculating the brake fluid back into the reservoir. - Using a dull object, slowly stroke the master-cylinder piston, air and brake fluid will be expelled from the brake line fittings. Prior to releasing the piston plug or cap the outlet ports. - Repeat this procedure 8-10 times or until no air is emitted from the outlet ports. - When finished, cap the outlet ports and install the master-cylinder. Syringe Fill the syringe (one especially designed for brake bleeding) with clean brake fluid. - Insert the end of the syringe into one of the outlet ports on the master-cylinder. - Slowly compress the syringe and back flush the brake fluid through the master-cylinder. - A combination of air and brake fluid will be emitted from the inlet port in the fluid reservoir. - Repeat this procedure until only brake fluid is emitted into the reservoir. - Cap the outlet ports and install the master-cylinder. Page 2591 Vehicle Speed Sensor: Service and Repair 1. Disconnect vehicle speed sensor electrical connector. 2. Remove sensor attaching bolt. 3. Using speed sensor remover and installer, tool No. J 38417, remove sensor, then O-ring seal. 4. Reverse procedure to install, coating the new O-ring seal with transmission fluid. Torque attaching bolt to 97 inch lbs. Page 6190 5. Place the Rotor and Bearing assembly on blocks as shown in Figure 11. Drive the bearing out of the rotor hub with Rotor Bearing Remover J 9398-A. It is not necessary to remove the staking at the rear of the rotor hub to remove the bearing. However, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore, or the bearing may be damaged (Fig. 12). Install or Connect 1. Place the Rotor and Hub assembly face down on a clean, flat and firm surface. 2. Align the new bearing squarely with the hub bore and using Pulley and Bearing Installer J 9481-A with Universal Handle J 29886, drive the bearing fully into the hub (Fig. 13). The Installer will apply force to the outer race of the bearing if used as shown. Page 6646 Figure 7 Figure 8 Figure 9 Figure 10 Page 1094 Fluid - A/T: Testing and Inspection Turbo Hydra-Matic 4L60 (700-R4) Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface, engine idling in park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, If fluid level is too low, complete loss of drive may occur especially when cold, Which can cause transmission failure. Every 100,000 miles, the oil should be drained, the pan removed, the screen should be cleaned or replaced if applicable, and fresh fluid added. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or use as a tow vehicle, this maintenance should be performed every 15,000 miles. Page 4504 Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Page 666 Throttle Position Sensor: Service and Repair Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 7674 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 1678 - Charge NC system. Page 1219 Vehicle Limited Warranty, dealers are instructed to proceed as follows: Important: On vehicles equipped with A/C systems NOT produced by GM (i.e., rear A/C systems in van conversions), consult the manufacturer of that A/C system for retrofit guidelines. ^ Offer the customer the option of repairing and recharging the system with R12, or retrofitting after repair and recharging with R-134a at no additional charge. ^ Provide the owner with, and review the information contained in, the "Converting Your Auto Air Conditioning System to Use the New Refrigerant" brochure. (Brochure, Form GM-0011, can be ordered free of charge from GM Fulfillment HQ, Phone 1-800-269-5100). ^ Record the customer's choice on the repair order and, as with all properly completed repair orders, ask the customer to sign on the appropriate line acknowledging the repairs requested. ^ Under no circumstances should the retrofit to R-134a be performed unless the customer has had the option explained prior to repair. Once the vehicle has been retrofitted to R-134a, a significant expenditure would be incurred to go back to R-12, in the event the customer has changed his/her mind. THIS OFFER APPLIES ONLY TO VEHICLES REQUIRING A/C REFRIGERANT SYSTEM REPAIRS UNDER THE TERMS OF THE NEW VEHICLE LIMITED WARRANTY. It is not a special policy, and any existing deductibles still apply. This is simply an option being offered to the customer during the warranty period at this time. GM reserves the right to terminate this offer at any time. If the R-12 refrigerant system does not require discharging for a warranty repair, but the customer requests a retrofit to R-134a, the retrofit WOULD BE PERFORMED AT THE CUSTOMER'S EXPENSE, EVEN DURING THE WARRANTY PERIOD. 2. Customer Paid Retrofitting Costs If the customer requests a retrofit to R-134a, for a specific vehicle whose retrofit parts and procedures have been released in this bulletin, the customer would be expected to pay the costs to retrofit under the following conditions: ^ The vehicle is no longer covered by the terms of the New Vehicle Limited Warranty. ^ The vehicle is covered by warranty, but the repair covered under the warranty does not require evacuating and recharging the refrigerant system. 3. Labor Time Information For Vehicles Repaired Under Warranty: Use existing labor operations for correcting the original condition. The quantity of R-134a used should be charged to the normal labor operation (not D4500), just as if it were R-12. Use D4500, 0.3 HR., to charge for parts and labor, for all of the following items: ^ Additional time for recovery of R-12 to meet SAE standards; ^ Install high and low side service port converter fittings; ^ Add PAG or V5 retrofit oil; ^ Complete label information and install. Add 0.2 hours to D4500 for installation of the HPCOS. Use T5321, 0.3 HR., for the Pontiac Bonneville hood seal installation. ANY PARTS OR LABOR TIME OTHER THAN THOSE LISTED ABOVE SHOULD BE CHARGED TO THE REGULAR LABOR OPERATION CORRESPONDING TO THE ORIGINAL CONDITION THAT 1S BEING REPAIRED. Page 79 Figure 7 Figure 8 Figure 9 Figure 10 Page 8362 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Instrument Panel - Upper Surface Reflection Instrument Cluster / Carrier: Customer Interest Instrument Panel - Upper Surface Reflection File In Section: 08 - Body and Accessories Bulletin No.: 99-08-49-006 Date: April, 1999 INFORMATION Subject: Cleaning of Upper Instrument Panel Surfaces Models: 1999 and Prior Passenger Cars and Light Duty Trucks Comments on a reflection of the upper instrument panel pad into the windshield, when driving in direct sunlight, may be received. This condition, sometimes referred to as a "veiling reflection", may be aggravated by the use of wax or silicone based products when cleaning the surface. Advise customers, technicians and new car prep or make ready personnel, that products containing wax or silicone should not be used to clean the top instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap or an equivalent, should be used whenever the top instrument panel pad needs cleaning. If a customer requests that a protectant type product be applied, ONLY USE THOSE THAT LEAVE A FLAT OR SATIN FINISH. Do NOT apply products that leave a glossy finish or those that Increase the shine level above the original production level. Page 342 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 7569 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 982 Labor Operation Labor Time T7460 0.2 hours Clean A/C pulley and inspect for proper alignment 0.2 hours Loosen and align P/S pump pulley (include R and R lower shroud) Note: T7460 is coded to base vehicle coverage in the warranty system. For vehicles repaired under warranty for replacing serpentine belt use: Labor Operation Description Labor Time J0667 Belt-Drive, Replace See Applicable Labor Time Guide Page 6438 accumulator. The system will operate properly as long as refrigerant charge amounts are strictly adhered to. 6. Refrigerant Charge Level The retrofit R-134a charge level is more critical than with R-12 systems. Overcharging may push the mineral oil out of the AID, and cause it to circulate as a liquid. This is more likely to result in compressor damage. Undercharging may lead to loss of performance. It is very important to clear the hoses during the charging operation, to insure that all the refrigerant is delivered to the vehicle A/C system. This is covered in Step 6D of the Retrofit Procedure. C. Parts Information Page 8743 Note: Labor Operation is coded to base vehicle coverage in the warranty system. Wheels - Sealing Leaking Cast Aluminum Wheels: All Technical Service Bulletins Wheels - Sealing Leaking Cast Aluminum Bulletin Number: 93-3-16 Reference Number: 393504 Publish Date: 7/93 Subject: LEAKING CAST ALUMINUM WHEELS (REPAIR WITH ADHESIVE SEALANT) Models Affected: 1985-1993 ALL MODELS Should a vehicle equipped with cast aluminum wheels exhibit a slow leak due to a porous condition existing in the wheel, the wheel can be repaired by using Dow Corning Silastic 732 RTV, p/n 1052366 or equivalent, as described in the following procedure: 1. Remove tire-wheel assembly from vehicle. 2. Locate leaking area by inflating tire to 40 psi and dipping tire-wheel assembly in water bath. 3. If air bubbles are observed, mark leak area and remove tire from wheel. 4. Scuff INSIDE rim surface at leak area with # 80 grit paper and clean area with general purpose cleaner, such as 3M # 08984. 5. Apply 1/8" thick layer of adhesive/sealant to leak area on INSIDE of rim and allow six hours of drying time. 6. Mount tire on wheel, pressurizing to 40 psi and check for leaks. NOTICE: Caution must be used when mounting the tire so as not to damage the sealer. 7. Adjust tire pressure to meet placard specification. 8. Balance tire-wheel assembly, using proper coated weights. 9. Water test wheel again. 10. Reinstall tire-wheel assembly on vehicle. Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation Number: E0420 Page 5082 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 8282 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 5594 Page 1211 FOR ALL VEHICLES EXCEPT GEO, see the "Compressor Replacement Chart" at the end of this section. Compressor replacement requirements ARE NOT LISTED in the platform details (except for application details), except as noted below for Y car and P and Medium Duty truck. Compressor Replacement Chart Important: It is important to check the date code on the compressor. Any vehicle may have had a compressor replaced either during or after the warranty period. The date code will determine whether or not the compressor must be replaced. Compressor Availability A new compressor for use with R-134a systems will be shipped with the correct amount of PAG oil installed (see "IMPORTANT" below). Do not add any additional oil in Step 5 of the retrofit procedure if a compressor is to be replaced with a new R-134a compressor at the same time the initial retrofit is Page 8206 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 3466 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Page 6164 2. Place the pulley rotor and bearing assembly on the neck of the front head and seat the clutch coil and pulley rotor in place using Rotor and Bearing Installer J 26271-A (Fig. 14). Before fully seating the assembly on the front head, be sure the clutch coil terminals are in proper location in relation to the compressor and that the three protrusions on the rear of the clutch coil housing align with the locator holes in the front head. 3. Install the pulley-rotor and bearing assembly retaining ring and reassemble the clutch plate and hub assembly. 4. Check to see that the clutch plate to clutch rotor air gap is 0.5-7.6mm (0.020-0.030"). Diagram Information and Instructions Trailer Adapter Kit: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 5728 Page 359 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 1340 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 8696 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Page 356 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 6087 Blower Motor Does Not Operate In HI Blower Motor Does Not Operate In LO Blower Inoperative Page 8279 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Tires/Wheels - Tire Puncture Repair Procedures Tires: All Technical Service Bulletins Tires/Wheels - Tire Puncture Repair Procedures INFORMATION Bulletin No.: 04-03-10-001F Date: April 27, 2010 Subject: Tire Puncture Repair Procedures For All Cars and Light Duty Trucks Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-001E (Section 03 - Suspension). This bulletin covers puncture repair procedures for passenger car and light duty truck radial tires in the tread area only. The tire manufacturer must be contacted for its individual repair policy and whether or not the speed rating is retained after repair. Caution - Tire changing can be dangerous and should be done by trained professionals using proper tools and procedures. Always read and understand any manufacturer's warnings contained in their customers literature or molded into the tire sidewall. - Serious eye and ear injury may result from not wearing adequate eye and ear protection while repairing tires. - NEVER inflate beyond 275 kPa (40 pounds) pressure to seat beads. Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. - NEVER stand, lean or reach over the assembly during inflation. Repairable area on a radial tire. Important - NEVER repair tires worn to the tread indicators 1.59 mm (2/32") remaining depth). - NEVER repair tires with a tread puncture larger than 6.35 mm (1/4"). - NEVER substitute an inner tube for a permissible or non-permissible repair. - NEVER perform an outside-in tire repair (plug only, on the wheel). - Every tire must be removed from the wheel for proper inspection and repair. - Regardless of the type of repair used, the repair must seal the inner liner and fill the injury. - Consult with repair material supplier/manufacturer for repair unit application procedures and repair tools/repair material recommendations. Three basic steps for tire puncture repair: 1. Remove the tire from the wheel for inspection and repair. Page 4658 Brake Pad: Service and Repair Installation Caliper Assembly 1. Lubricate new sleeves, rubber bushings, bushing grooves and mounting bolt ends with Delco Silicone Lube or equivalent. 2. Install new bushings and sleeves on caliper ears. Position the sleeve so that the end toward the pad is flush with the machined surface of the ear. 3. Install pad retaining spring on inner pad. 4. Position inner pad in caliper so spring ends centrally contact pad edge. Initially, this will place the pad on an angle. Push upper edge of pad down until pad is flat against caliper. When properly seated, spring ends will not extend past pad more than 2.4 mm (0.1 inch). 5. Position outer pad in caliper with pad ears over caliper ears and tab at bottom of pad engaged in caliper cutout. 6. Install caliper. See Brake Caliper / Service and Repair. See: Brake Caliper/Service and Repair CAUTION: Make sure that the brake hose is not twisted or kinked since damage to the hose could result. Compressing The Pad Ears 7. Compress the pad ears to the caliper. Page 3734 [99] Driveability correction for heavy chuggle. REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [100] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). Page 4849 Vacuum Pump: Testing and Inspection GEAR DRIVEN PUMP 1. Start engine, then attach hose and vacuum gauge to pump. Gauge should read at least 20 inches Hg. 2. Shut off engine. Vacuum level should remain above 19 inches Hg. for at least 1-1/2 seconds. BELT DRIVEN PUMP Fig. 1 Vacuum Chart 1. Block wheels, apply parking brake, and place gear shift lever in P or N. 2. Connect vacuum gauge to vacuum pump inlet (lower port). 3. Disconnect outlet hose from outlet tube (upper port) and plug end of hose. Do not plug vacuum pump outlet tube. 4. Start engine and run at idle. Vacuum should read as shown, Fig. 1, within 30 seconds. 5. If vacuum is within specifications, proceed to step 8. 6. If vacuum is below specification or gauge reading fluctuates, proceed as follows: a. Check gauge and connections for leaks, correcting as necessary. b. Check belt tension and pulley fit to pump, repairing or replacing as necessary. c. Check idle speed and correct as necessary. 7. If vacuum is still below specifications or gauge still fluctuates, replace vacuum pump and repeat steps 1 through 6. 8. If vacuum was within specifications in step 5 or step 7, proceed as follows: a. Remove plug from outlet hose and connect hose to pump outlet tube. b. Connect vacuum inlet hose to pump with a T-fitting and vacuum gauge located near pump inlet. c. Start engine and run at idle for one minute. d. If vacuum is three inches Hg. lower than in step four, vacuum pump is not defective. e. If vacuum is more than three inches Hg. lower than in step four, check all attaching hoses for leaks, correcting as necessary. f. If vacuum is still too low, check all vacuum accessories for leaks, repairing or replacing as necessary. Diagram Information and Instructions Fuse Block: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 4113 Windshield/A Pillar - Pop Noise Diagnosis Dashboard / Instrument Panel: Customer Interest Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Page 7719 Cigarette Lighter: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 1289 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 4048 Torque Converter: Testing and Inspection 1. Converter clutch pressure plate damaged. 2. Check ball on end of turbine shaft damaged. 3. Sticking converter clutch shift valve in valve body. 4. Sticking converter clutch apply valve in valve body. 5. Restricted converter clutch apply passage. 6. Low oil or oil pressure. 7. Engine not tuned properly. Page 8004 Door Switch: Locations RH Rear Door Jamb Switch In RH B-Pillar Description and Operation Thermostatic Air Cleaner: Description and Operation Air Cleaner With Heated Air Intake System Thermac Operation DESCRIPTION A heated intake air system is used for good driveability under varying climatic conditions. Having a uniform inlet air temperature improves fuel vaporization. OPERATION The THERMAC system regulates in incoming air temperature without the use of vacuum. The air regulating damper is controlled by means of a self contained, wax pellet actuated assembly mounted in the air cleaner. When incoming air is cold, the wax material sealed in the actuator is in a solid phase and the damper closes off the cold air inlet. This causes all incoming air to be heated by the exhaust manifold. As the incoming air warms, the wax material expands changing to a liquid phase which forces out a piston to reposition the damper allowing a cold and hot air mix or all cold air to enter the engine. Page 940 Spark Plug Wire: Description and Operation CONSTRUCTION The spark plug/coil secondary wiring is a carbon impregnated cord conductor encased in a rubber jacket. The 7-mm wire used on the 2.5L and 2.8L engines and the 8-mm wire used on the 3.1L, 4.3L, 5.0L, 5.7L and 7.4L has an outer layer of silicone. The silicone jacket withstands very high temperature and also provides an excellent insulator for the higher voltage of the electronic ignition system. The silicone spark plug boots form a tight seal on the plugs and distributor cap. CAUTION - Care should be exercised when connecting a timing light or other pick-up equipment. - Do not force anything between the boot and wiring. - Do not pierce the secondary wire insulation. - Use only equipment with an inductive pickup to check for spark plug firing. - Do NOT pull on the wire to remove. The boot should be twisted 1/2 turn before removing. Pull on the boot, or use a tool designed for this purpose. With A-6 Compressor Compressor Clutch: Service and Repair With A-6 Compressor Clutch Plate and Hub Assembly Remove or Disconnect Tools Required: J 9396 Compressor Holding Fixture J 9399-A Compressor Shaft Nut Socket J 9401-B Hub Drive Plate Remove J 25030-A Clutch Hub Holding Tool Page 6652 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Page 981 This condition may be attributed to belt interference between the water pump pulley and belt tensioner pulley (Figure 1). The belt tensioner pivots both directions from the center pivot axis which can result in the serpentine belt coming in contact with itself at the water pump pulley. To correct this condition, loosen the generator bracket bolts (3) and move the top of the bracket to its most outward position (Figure 1). This will move the tensioner pulley away from the water pump pulley increasing clearance, to eliminate contact. Tighten the generator bracket bolts after the bracket has been repositioned. **NOTE: Some cleaning agents or mineral oils can attack the belt compound and should not be used in this location. This may be another contributor to premature wear. If a new serpentine belt is required for the chirping sound or premature wear, new accessory drive serpentine belts have been released to GMSPO. The new belts will supersede the existing part numbers. SERVICE PARTS INFORMATION: Part Number Description Qty. 10210382 Belt-Fan w/o C60, C69 1 10210383 Belt-Fan w C60, C69 1 S/T and C/K An improved belt is available for use on 1990 through 1993 S/T and C/K trucks with L35, LB4, L03, or L05 engines equipped with C60 (air conditioning) but without K19 (A.I.R.). The new belt is less prone to "chirping." If, after performing standard diagnostic procedures, a serpentine belt replacement is required, use P/N 10189265. NOTE: P/N 10189265 replaces P/N 10069211. Parts are currently available from GMSPO. WARRANTY INFORMATION: Page 7445 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Page 8535 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 8194 Symbol Identification Page 1530 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Page 1306 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7133 Seat Cover: Technical Service Bulletins Interior - Elimination Of Unwanted Odors INFORMATION Bulletin No.: 00-00-89-027E Date: September 29, 2008 Subject: Eliminating Unwanted Odors in Vehicles Models: 2009 and Prior GM Passenger Cars and Trucks (including Saturn) 2009 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and refine the instructions. Please discard Corporate Bulletin Number 00-00-89-027D (Section 00 - General Information). Vehicle Odor Elimination General Motors offers a product that may control or eliminate odors in the interior and luggage compartment areas of GM vehicles. GM Vehicle Care Odor Eliminator is a non-toxic, biodegradable odor remover. This odorless product has been shown to greatly reduce or remove objectionable smells of mold and mildew resulting from vehicle water leaks (as well as customer created odors, i.e. smoke). You may use GM Vehicle Care Odor Eliminator on fabrics, vinyl, leather, carpet and sound deadening materials. It may also be induced into HVAC modules and instrument panel ducts (for the control of non-bacterial related odors). Important: This product leaves no residual scent and should not be sold as or considered an air freshener. Product action may result in the permanent elimination of an odor and may be preferable to customers with allergies who are sensitive to perfumes. How to Use This Product GM Vehicle Care Odor Eliminator may be sprayed on in a ready-to-use formula or used in steam cleaners as an additive with carpet shampoo. This water-based, odorless product is safe for all vehicle interiors. Do not wet or soak any interior surface that plain water would cause to deteriorate, as this product will have the same effect. Also avoid letting this product come into contact with vinegar or any acidic substance. Acid-based products will hamper the effectiveness of, or render GM Vehicle Care Odor Eliminator inert. Note: Complete eight page treatment sheets are enclosed within each case of GM Vehicle Care Odor Eliminator. These treatment instructions range from simple vehicle odor elimination to full step by step procedures for odor removal from water leaks. If lost, contact 800-977-4145 to get a replacement set faxed or e-mailed to your dealership. Instructions and cautions are printed on the bottle, but additional help is available. If you encounter a difficult to eliminate or reoccurring odor, you may call 1-800-955-8591 (in Canada, 1-800-977-4145) to obtain additional information and usage suggestions. Important: This product may effectively remove odors when directly contacting the odor source. It should be used in conjunction with diagnostic procedures (in cases such as a water leak) to first eliminate the root cause of the odor, and then the residual odor to permanently correct the vehicle condition. Vehicle Waterleak Odor Elimination STEP ONE: Confirm that all water leaks have been repaired. Determine what areas of the vehicle were water soaked or wet. Components with visible mold/mildew staining should be replaced. Isolate the odor source inside the vehicle. Often an odor can be isolated to an area or component of the vehicle interior by careful evaluation. Odor evaluation may need to be performed by multiple persons. Another method of isolating an odor source is to remove and segregate interior trim and components. Plastic sheeting or drop cloths can be used to confine seats, headliners, etc. to assist in evaluation and diagnoses. If appropriate the vehicle and interior trim should be evaluated separately to determine if the odor stays with the vehicle or the interior components. Odors that stay with the vehicle may be isolated to insulating and sound deadening materials (i.e. water leak at the windshield or standing water in the front foot well area caused mold/mildew to form on the bulkhead or kick panel sound deadening pads. If the interior is removed the floor pan and primed/painted surfaces should be treated with bleach/soap solution, rinsed with clean water and dried. Interior surfaces should then be treated with GM Vehicle Care Odor Eliminator product before reinstalling carpet or reassembling. Page 2802 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 7215 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 8674 Front Door Trim Panel Components Tools Page 384 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Diagram Information and Instructions Relay Box: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 638 Manifold Pressure/Vacuum Sensor: Locations CMFI Intake Manifold Sensors/Valves Page 4744 Brake Caliper: Description and Operation Fig. 1 Exploded View The Delco-Moraine Single Piston Caliper is held in place by two mounting bolts. The caliper assembly, Fig. 1, slides on its mounting surfaces. Upon brake application, hydraulic pressure against the piston forces the inboard pad against the inboard side of the disc. This action causes the caliper assembly to slide until the outboard pad comes into contact with the disc, which in turn creates a slowing or stopping action. Page 1676 3. Balance shaft bearing retainer and bolts. Tighten Bolts to 14 Nm (120 in. lbs.). 4. Balance shaft driven gear and bolt. Tighten Bolt to 20 Nm (15 ft. lbs.) plus an additional 35 degrees. 5. Lifter retainer. - Rotate the balance shaft by hand to make sure there is clearance between the balance shaft and the lifter retainer. Replace the lifter retainer if necessary. 6. Turn the camshaft so, with the balance shaft drive gear temporarily installed, its timing mark is straight up. 7. With the balance shaft drive gear removed, turn the balance shaft so the timing mark on the driven gear points straight down. 8. Balance shaft drive gear onto the camshaft. Important - Be sure that the timing marks on the balance shaft drive gear and the driven gear line up dot to dot. 9. Balance shaft drive gear retaining stud. Tighten Stud to 16 Nm (12 ft. lbs.). 10. Intake manifold, as outlined in this section. 11. Camshaft sprocket and timing chain. Important: Line up the timing marks on the camshaft sprocket and crankshaft sprocket dot to dot (figure 41). When these marks are lined up dot to dot, the number four cylinder is at top dead center of its compression stroke. The distributor rotor will need to be positioned facing the number four terminal on the distributor cap when installed. 12. Camshaft sprocket bolts and nut. Tighten Bolts and nut to 28 Nm (21 ft. lbs.). 13. Distributor. 14. Distributor wiring. 15. Front cover and front cover bolts. Page 4790 Pedal Reserve Checks - The pedal should be firm and not leak down. Prior to replacing a master-cylinder for poor pedal travel or feel verify the following: There were no problems with any of the related systems. - The entire brake system has been bled. - Rear brakes are properly adjusted. Page 6562 powered during engine cranking. The return lead of the contactor coil must return to a proper fused negative point. c. Handset or Control Units 1. Any negative power lead from a handset or control unit must return to a properly fused negative connection point. 2. It is preferable that the positive power lead for a handset, or control unit, be connected directly to a properly fused positive power feed point. If ignition switch control is desired, the handset or control unit positive power lead may be connected through an appropriate in-line fuse to an available accessory circuit (or ignition circuit not powered during engine cranking). 3. It is recommended that the handset or control unit positive and negative power leads be appropriately fused separately from the transceiver positive and negative power leads. d. Multiple Transceivers or Receivers If multiple transceivers or receivers are to be installed in the vehicle, power leads to the trunk or under the dash should be connected to covered, insulated terminal strips. All transceivers or receivers may then have their power leads connected to the insulated terminal strips. This makes a neater installation and reduces the number of wires running to the vehicle underhood area. Both positive and negative power leads should be fused. 6. Radio Wire Routing (See Figure 1 - One Piece Transceiver Installation, or Figure 2 - Trunk Mount Transceiver Installation as needed). a. The power leads (fused) should be brought through a grommeted hole (provided by the installer) in the front cowl. For trunk mounted transceivers, the cables should continue on along the driver's side door sills, under the rear seat and into the trunk through a rear bulkhead. Maintain as great a distance as possible between radio power leads and vehicle electronic modules and wiring. b. If the radio power leads need to cross the engine compartment, they should cross between the engine and the front of the vehicle. Troubleshooting Refer to the Troubleshooting Chart as needed. 1. Most vehicle-radio interaction is avoided by following the Installation Guidelines outlined above. 2. If vehicle-radio interaction is evident following radio installation, the source of the problem should be determined prior to further vehicle/radio operation. The EMC Troubleshooting Chart should help in determining the source of the vehicle-radio interaction. Parts Information P/N Description 1846855 Adapter Kit, Side Terminal Battery (consisting of Adapter Terminal, Terminal Cover, Wire Connector, Insulation Boot) 12004188 Bolt, Battery Cable Terminal 12354951 Spacer, Battery Cable Terminal Parts are currently available from GMSPO. Page 2266 Fan Clutch: Description and Operation Fan Drive Clutch Assembly Variable Speed Fan W/Bi-Metallic Coiled Thermostatic Spring The fan drive clutch, Fig. 1, is a fluid coupling containing silicone oil. Fan speed is regulated by the torque-carrying capacity of the silicone oil. The more silicone oil in the coupling, the greater the fan speed, and the less silicone oil, the slower the fan speed. The type of fan drive clutch in use is a coiled bimetallic thermostatic spring, Fig. 2. The fan drive clutch uses a heat-sensitive, coiled bimetallic spring connected to an opening plate which regulates the flow of silicone oil into the coupling from a reserve chamber. The silicone oil is returned to the reserve chamber through a bleed hole when the valve is closed. This unit causes the fan speed to increase with a rise in temperature and to decrease as temperature decreases. Page 3472 CMFI Intake Manifold Sensors/Valves Page 2046 27. Balance shaft rear bearing using J 38834 and J 26941. Important - The balance shaft and both bearings are serviced only as a complete package. - Use only the correct tools for bearing and shaft installation. - The front bearing must not be removed from the balance shaft. - The balance shaft drive and driven gears are serviced only as a set. The set includes the balance shaft driven gear bolt. Clean All traces of old gasket material from gasket sealing surfaces. Inspect Balance shaft drive and driven gears for nicks and burrs. Install Tools Required: J 23523-E Torsional Damper Puller and Installer. J 38834 Balance Shaft Bearing Service Kit. J 36996 Shaft Installer J 8092 Driver Handle J 35468 Crankshaft Seal Installer Cruise Control - Works Intermittently Cruise Control Switch: All Technical Service Bulletins Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Page 582 Turn Signal Switch: Service and Repair Fig. 6 Compressing Lock Plate 1. Disconnect battery ground cable. 2. Remove steering wheel as outlined under STEERING WHEEL & HORN SOUNDER. 3. Using a screwdriver, pry cover from lock plate. 4. Using lock plate compressing tool No. J-23653, compress lock plate and pry retaining ring from groove on shaft, Fig. 6. Slowly release lock plate compressing tool, remove tool and lock plate from shaft end. 5. Slide canceling cam and upper bearing preload spring from end of shaft. 6. Remove turn signal (multi-function) lever. 7. Remove hazard warning knob retaining screw, button, spring and knob. 8. Remove pivot arm. 9. Remove switch retaining screws and pull switch up from column, guiding wire harness through column. 10. Reverse procedure to install. Page 5239 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 3567 Spark Plug Wire: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Page 1358 Malfunction Indicator Lamp: Description and Operation PURPOSE The Malfunction Indicator Lamp (MIL), "Service Engine Soon" light has the following purposes: Inform the driver that a problem has occurred, and that the vehicle should be taken for service as soon as reasonably possible. - Displays Diagnostic Trouble Codes (DTC) stored by the ECM helping the technician diagnose system faults. - Indicates "Open Loop" or "Closed Loop" operation. OPERATION The MIL will come "ON" with the key "ON" and the engine not running. When the engine is started, the light will turn "OFF.". This is a bulb and system check. If the light remains "ON," the self-diagnostic system has detected a problem. If the problem goes away, the light will go out in most cases after 10 seconds, but a DTC will remain stored in the ECM. Page 7105 DATE: July 1993 SUBJECT: SERVICE PROCEDURES FOR IDENTIFICATION AND REPAIR OF PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER MODELS: 1988-92 TRUCKS THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 92-10-134 (CORP # 231054R), DATED OCTOBER 1992. IT IS BEING REVISED TO REMOVE THE COVER LETTER PORTION AND SUBJECT STATEMENT NOW INCLUDES NOTE FOR TRUCKS AND REVISES THE MONOCOAT MATERIAL ALLOWANCES ON "G", "S/T" AND SOME "R/V" MODELS. THE ALLOWANCE FOR "ADD FOR TWO-TONE" ON G AND S/T TRUCKS HAS BEEN CHANGED. ALL COPIES OF 92-10-134 SHOULD BE DISCARDED. The revisions are the result of changes to the MONOCOAT (ENAMEL) material allowance charts published in June, 1993. Six (6) of the "G" model revisions use Basecoat/Clearcoat material allowance codes. THESE ARE TO BE USED AS DOLLAR REFERENCES ONLY, AND ARE MARKED WITH A # INDICATOR. Continue to repair these vehicles with monocoat materials. DO NOT repair these vehicles with Basecoat/Clearcoat products. Use the latest (June, 1993) material allowance charts when submitting claims. SUBJECT: Service procedures for the repair of paint colorcoat delamination from elpo primer (repaint entire body above the body side moldings, except trucks as noted). APPLICATION: 1988-1992 LIGHT DUTY TRUCKS (C/K, R/V, S/T, M/L AND G) This bulletin cancels and supersedes service procedures and time allowances on all previous bulletins regarding paint DELAMINATION. Due to the use of new procedures, add times for optional equipment, and designating specific hardware items for removal, the published labor times will not be the same as previously published. CONDITION This bulletin is being issued to assure that the correct procedure is followed to repair a condition known as DELAMINATION. Some of the above listed passenger cars, light duty trucks, and vans may have DELAMINATION (peeling) of the paint color-coat from the ELPO primer depending upon variable factors including prolonged exposure to sunlight and humidity. Blues, Grays, Silvers and Black Metallics are the colors that have the highest potential for this condition. On rare occasions, other colors may be involved. Important DELAMINATION is different than other paint conditions and/or damage. A proper problem identification is necessary, and the service procedure that follows is specific to the proper repair of DELAMINATION and must be followed. The information in this bulletin covers Paint DELAMINATION of the colorcoat from the ELPO primer ONLY. It does not address any other paint conditions. Procedures for the repair of other paint conditions (stone chips, scratches, environmental damage, clearcoat peeling, runs, dirt, fading, etc.) will not effectively repair DELAMINATION and customer dissatisfaction will result. CAUSE This condition may occur on vehicles produced in plants where the paint process does not call for application of a primer surfacer. Under certain conditions, ultraviolet light can penetrate the colorcoat, sometimes causing a reaction and separation of portions of the colorcoat from the ELPO (electrocoat) primer. PROBLEM IDENTIFICATION: On a clean surface, at or above room temperature, firmly apply a 2" wide piece of masking tape and pull upward quickly. DO NOT USE duct tape, cloth backed tape or other aggressive tapes. If the colorcoat flakes or peels away from the ELPO (leaving the ELPO intact) the colorcoat is delaminating and the vehicle should be repaired using the "Paint Repair Procedure" contained in this bulletin. This test SHOULD ONLY BE APPLIED TO A VEHICLE SHOWING THE CONDITION, (peeling/delamination) and NOT in areas of stone chipping or other obvious damage. These "other" conditions should be repaired following standard paint repair procedures. CORRECTION Refinish the ENTIRE BODY ABOVE THE BODY SIDE MOLDINGS using the following repair procedure. It is important that ALL surfaces above the body side moldings (including recessed areas around door handles) be refinished, as these surfaces may show the same DELAMINATION (peeling) Page 7106 condition at a later date. Note: Many vehicles have some type of plastic exterior body panels (cowl vent grilles, fascias, front end panels, rear fenders, etc.). These panels are not subject to DELAMINATION and therefore do not require refinishing. If painting of these panels is required for color uniformity, scuff sand and colorcoat only (and clearcoat if basecoat/clearcoat system is used). Note: Two tone lines, feature lines or body side molding treatments near mid-door height are appropriate break lines. If no such convenient break lines are present, the entire panel above the next lower break line must be refinished and the portion of the panel below that break line should be COLORCOATED ONLY (and clearcoated if basecoat/clearcoat system is used) for color uniformity of the repair. Note: Pickup boxes which are covered by caps, bedliners or tonneau covers do not receive direct exposure to sunlight, and normally would not be repaired under this procedure. However, if the inside of the box has been uncovered and experienced DELAMINATION, use the appropriate Labor Operation Number. Note: Certain two tone applications on trucks using the high potential colors (Blues, Grays and Silvers) may require that only portions of the vehicle surface be refinished. Examples would be: Example 1. Blues, Grays and Silvers as "insert colors" on vertical surfaces with other, non-high potential colors above the insert (or break line). Action: Refinish the "insert color" only, between the break line and body side molding (or to the lower feature line on certain vehicles). Example 2. Blues, Grays and Silvers on surfaces above the break line with other, non-high potential colors as "insert colors". Action: Refinish the surfaces above the "insert color" or break line only. Example 3. Blues, Grays and Silvers used as both the primary and "insert colors". Action: Refinish both high potential color surfaces above the body side moldings (or to the lower feature line on certain vehicles). Vehicles should be repaired with the same type materials they were manufactured with; repair basecoat/clearcoat with basecoat/clearcoat materials and monocoat with monocoat. PAINT REPAIR PROCEDURE 1. Some vehicle components will be removed from the vehicle while others will require masking. The list located at the end of this bulletin will establish the removal items. Items not found on the list and non-repair areas are to be masked. 2. Prior to removing the paint finish, clean the area to be refinished with an appropriate wax and grease remover to remove any contaminants. 3. Remove the original finish of paint down to the ELPO primer surface using an orbital D.A. sander, leaving the ELPO surface intact. This can be done in "stages" using 80 grit (or finer) discs to remove the majority of coating, followed with 180 grit (or finer) discs to remove the remainder of material down to the ELPO surface and any chalky residue or degraded ELPO that may remain. Avoid sanding through ELPO to bare metal in order to retain maximum corrosion protection. - An alternative in some geographic areas may be plastic media blasting such as may be provided by members of: - Dry Stripping Facilities Network 1-800-634-9185 * * We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Important Additional time or payment beyond established allowances in this bulletin will not be allowed. - The use of a razor blade on large flat surfaces is not recommended because of the potential to chip. gouge or otherwise damage the primer surface. If razor blade technique is used, the application of a "guide coat" prior to wet sanding should also be used. Page 2163 Processes shown in the Table 3 are capable of recycling waste engine coolants (DEX-COOL(R) or conventional) to a conventional (green) coolant. Recycling conventional coolant can be accomplished at your facility by a technician using approved EQUIPMENT (listed by model number in Table 3), or by an approved coolant recycling SERVICE which may recycle the coolant at your facility or at an offsite operation. Refer to the table for GM approved coolant recyclers in either of these two categories. Should you decide to recycle the coolant yourself, strict adherence to the operating procedures is imperative. Use ONLY the inhibitor chemicals supplied by the respective (GM approved) recycling equipment manufacturer. Sealing Tablets Cooling System Sealing Tablets (Seal Tabs) should not be used as a regular maintenance item after servicing an engine cooling system. Discoloration of coolant can occur if too many seal tabs have been inserted into the cooling system. This can occur if seal tabs are repeatedly used over the service life of a vehicle. Where appropriate, seal tabs may be used if diagnostics fail to repair a small leak in the cooling system. When a condition appears in which seal tabs may be recommended, a specific bulletin will be released describing their proper usage. Water Quality The integrity of the coolant is dependent upon the quality of DEX-COOL(R) and water. DEX-COOL(R) is a product that has enhanced protection capability as well as an extended service interval. These enhanced properties may be jeopardized by combining DEX-COOL(R) with poor quality water. If you suspect the water in your area of being poor quality, it is recommended you use distilled or de-ionized water with DEX-COOL(R). "Pink" DEX-COOL(R) DEX-COOL(R) is orange in color to distinguish it from other coolants. Due to inconsistencies in the mixing of the dyes used with DEX-COOL(R), some batches may appear pink after time. The color shift from orange to pink does not affect the integrity of the coolant, and still maintains the 5 yr/150,000 mile (240,000 km) service interval. Back Service Only use DEX-COOL(R) if the vehicle was originally equipped with DEX-COOL(R). Page 1232 4. Open the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (figure 2). Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Locations Combination Switch: Locations LH Side Of Instrument Panel. On Steering Column Applicable to: Except Bravada Page 4325 11. Hold flange with suitable tool and remove pinion shaft nut and flange. 12. Lubricate pinion shaft oil seal and cover outer edge of seal body with non-hardening sealing compound, then press seal against cover shoulder with suitable tool. 13. Install new gasket and bearing cover. 14. Press flange against forward bearing and install washer and pinion shaft nut, torquing nut to 240 ft. lbs. Page 8291 Symbol Identification Page 3695 For vehicles repaired under warranty use: Page 1290 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 1416 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 2541 Oxygen Sensor: Specifications Sensor Voltage Range Sensor Voltage Range Sensor Voltage (Closed Loop) 0.1 to 1.0 V Fuel Gage Indicates Empty When There Is Fuel In Tank Fuel Gage Indicates Empty When There Is Fuel In Tank Page 1281 Symbol Identification Page 5825 1. Use a proper hand reamer, carbide cutter or drill bit to ream the puncture channel from the inside of the tire in order to clean the injury. 2. Remove steel wires protruding above the liner surface to prevent damage to the repair unit. 3. Consult your repair material supplier for recommended reaming tool(s). Fill the Injury 1. It is necessary to fill the injury channel to provide back up for the repair unit and to prevent moisture from entering the tire fabric and steel wires. 2. (For combination repair/plug units skip this step.) Cement the injured channel and fill the injury from the inside of the tire with the repair plug per repair material manufacturer's recommendations. Without stretching the plug, cut the plug off just above the inside tire surface. 3. Consult your repair material supplier for proper repair material selection. Repair Unit Selection Important Do not install the repair unit in this step. Engine - Valvetrain/Lifter Noise Lifter / Lash Adjuster: Customer Interest Engine - Valvetrain/Lifter Noise Group Ref.: Engine Bulletin No.: 376006 Date: December, 1993 SUBJECT: VALVETRAIN/LIFTER NOISE (ADJUST LASH/INSTALL ADJUSTABLE LASH) MODELS: 1992-93 C/K AND S/T TRUCKS; M/L AND G VANS WITH LB4 4.3L V6 TBI (VIN Z) OR L35 4.3L V6 CPI (VIN W) ENGINE THIS BULLETIN CANCELS AND SUPERSEDES CORPORATE BULLETIN 376107. PLEASE DISCARD PREVIOUS DIVISIONAL PUBLICATIONS: (see illustration) CONDITION: Some owners may report a tick, click, or clatter noise occurring on start up, with the engine hot and/or cold. This valvetrain/lifter noise may last up to one minute. CORRECTION: Page 751 Figure 7 Figure 8 Figure 9 Figure 10 Page 8518 Symbol Identification Page 7519 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 6914 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Body - Marks/Stains on Windshield When Wet Windshield: All Technical Service Bulletins Body - Marks/Stains on Windshield When Wet TECHNICAL Bulletin No.: 09-08-48-002A Date: March 19, 2009 Subject: Marks/Stains on Windshield When Wet (Clean Windshield) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Supercede: This bulletin is being revised to update the models and model years. Please discard Corporate Bulletin Number 09-08-48-002 (Section 08 - Body and Accessories). Condition Some owners may comment that marks/stains appear on the windshield when the windshield is wet. Cause This condition may be caused by contact between the windshield and the vacuum hoses or other tools used in the assembly process. This contact may leave a residue that creates a water repellent surface on the glass which, in wet conditions, appear as marks/stains on the surface. Correction Important DO NOT REPLACE THE WINDSHIELD FOR THIS CONDITION. To clean the windshield, use Eastwood Glass Polishing Compound*. Follow the manufacturer's directions for product use. Use only hand tools. DO NOT USE POWER TOOLS. Parts Information Eastwood Glass Polishing Compound 1-800-343-9353 (for overseas inquiries: +1-610-705-2200) http://www.eastwoodco.com/ *We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such items which may be available from other sources. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Tires/Wheels - Tire Puncture Repair Procedures Tires: All Technical Service Bulletins Tires/Wheels - Tire Puncture Repair Procedures INFORMATION Bulletin No.: 04-03-10-001F Date: April 27, 2010 Subject: Tire Puncture Repair Procedures For All Cars and Light Duty Trucks Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-001E (Section 03 - Suspension). This bulletin covers puncture repair procedures for passenger car and light duty truck radial tires in the tread area only. The tire manufacturer must be contacted for its individual repair policy and whether or not the speed rating is retained after repair. Caution - Tire changing can be dangerous and should be done by trained professionals using proper tools and procedures. Always read and understand any manufacturer's warnings contained in their customers literature or molded into the tire sidewall. - Serious eye and ear injury may result from not wearing adequate eye and ear protection while repairing tires. - NEVER inflate beyond 275 kPa (40 pounds) pressure to seat beads. Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. - NEVER stand, lean or reach over the assembly during inflation. Repairable area on a radial tire. Important - NEVER repair tires worn to the tread indicators 1.59 mm (2/32") remaining depth). - NEVER repair tires with a tread puncture larger than 6.35 mm (1/4"). - NEVER substitute an inner tube for a permissible or non-permissible repair. - NEVER perform an outside-in tire repair (plug only, on the wheel). - Every tire must be removed from the wheel for proper inspection and repair. - Regardless of the type of repair used, the repair must seal the inner liner and fill the injury. - Consult with repair material supplier/manufacturer for repair unit application procedures and repair tools/repair material recommendations. Three basic steps for tire puncture repair: 1. Remove the tire from the wheel for inspection and repair. Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Page 6689 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 6959 Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Locations Engine Wiring, LH Side Page 7664 Symbol Identification Page 6373 Select and install the proper R-134a fittings (shown in Figure 4) from the chart below, based on how the ACR4 couplers will attach. Also, remember to check for proper hood clearance with the conversion fittings. Try the straight fittings first. The two-piece high side fitting is used when the existing fitting is screwed into the pipe fitting (some 1992, and nearly all 1993 models, use these fittings). Use the 90° elbow if the straight fitting does not allow the ACR4 couplers to connect. Fitting Type High Side Low Side Straight 52467941 52467943 Straight Two-piece 52467324 N/A 90° Elbow 52469054 52469055 The fittings should be installed as follows: a. Remove the caps from the R-12 fittings. Remove any dirt or grease from the port threads using the thread cleaning wire brush, J 41265. Inspect the fittings for thread damage. If any damage is found, use the port thread restorer (J 41266 low side, J 41267 high side) to repair the thread. For the two-piece fitting, remove the existing R-12 fitting and discard it. Use tool J 38704A (previously released, not part of the above kit) to remove the fitting. Make sure to hold the line securely to prevent damage when removing the existing fitting. If the fitting cannot be removed easily, use the saddle clamp valve listed below and seal the R-12 port and cap permanently. b. Install the selected fitting onto the existing R-12 fitting. Leave the valve core in the straight fittings, and remove the valve core when using the 90° fittings. If the valve cores need to be removed at a later time, they can be removed with the straight conversion fittings in place. On the low side straight fitting, use the J 34611-A tool to remove the core pin in the conversion fitting, then remove the core valve from the original R-12 fitting. Always recover the charge before valve core removal. A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: Customer Interest A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Page 3496 ACCELERATOR CONTROL CABLE When performing service on the accelerator control cable, observe the following: The retainer must be installed with the tangs secured overhead of the stud. - The conduit fitting at both ends of the cable must have the locking tangs expanded and locked in the attaching holes. - The braided portion of the accelerator cable assembly must not come in contact with the front of the dash sealer during assembly, repair, or replacement of the assembly. - The flexible components (hoses, wires, conduits, etc.) must not be routed within 50 mm (2 inches) of the moving parts of the accelerator linkage outboard of the support unless the routing is positively controlled. REMOVE/DISCONNECT - Retainer from throttle lever stud - Retainer locking tangs from support bracket - Retainer from accelerator pedal rod or release cable from rod. - Retainer locking tangs from dash panel INSTALL/CONNECT - Retainer to dash panel. - Retainer to accelerator pedal rod or connect cable in rod slot. - Retainer to support bracket. - Retainer to throttle lever stud or connect cable to pulley. Locations Suction Throttling Valve: Locations Heater & A/C Components On Top Rear Of Accumulator Page 7738 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 714 Throttle Position Sensor: Mechanical Specifications Throttle Position Sensor 18 in.lb Page 4345 Axle Shaft Assembly: Description and Operation Dana/Spicer Full Floating Fig. 3 Axle, Hub & Drum Components. This axle, Fig. 3, is similar to Salisbury type units. However, the axle shafts are full floating and the drive pinion incorporates two shim packs. The inner shim pack controls pinion depth, while the outer pack controls pinion bearing preload. Page 3890 Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Page 3860 Page 8676 Front Door Trim Panel Page 3605 Ignition Control Module: Description and Operation PURPOSE The distributor reference signal provides the ECM with both engine RPM and crankshaft position information. This enables the ECM to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the ECM receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the ECM will not operate the injector. Page 6172 Clutch Coil Assembly Removal 2. Install J 33023-A puller pilot on front head of compressor. Also install J 8433-1 puller crossbar with J 33025 puller legs. 3. Tighten J 8433-3 forcing screw against the puller pilot to remove the clutch coil. Install or Connect 1. Place the clutch coil assembly on the front head with the terminals positioned at the "marked" location. 2. Place the J 33024 clutch coil installer over the internal opening of the clutch coil housing and align installer with the compressor front head. Page 137 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 5233 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Control Module Engine Control Module: Locations Control Module Figure 1 LOCATION Below RH Side Of I/P. Page 398 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). A/T - Torque Converter Replacement Information Torque Converter: All Technical Service Bulletins A/T - Torque Converter Replacement Information INFORMATION Bulletin No.: 01-07-30-010C Date: May 12, 2008 Subject: Automatic Transmission/Transaxle Torque Converter Replacement Models: 2009 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saturn Cars and Light Duty Trucks (Except VTi Equipped Vehicles (RPO M16 and M75) 2009 and Prior Saab 9-7X with ALL Automatic Transmissions and Transaxles Supercede: This bulletin is being revised to add the 2007-2009 model years. Please discard Corporate Bulletin Number 01-07-30-010B (Section 07 - Transmission/Transaxle). The purpose of this bulletin is to help technicians determine when a torque converter should be replaced. Below is a list of general guidelines to follow. The converter should NOT be replaced if the following apply: ^ DTC P0742 - TCC stuck on is set. This code is almost always the result of a controls condition (i.e. stuck TCC solenoid/valve). Experience has shown that this code rarely indicates a mechanical concern within the torque converter. ^ The fluid has an odor or is discolored but no evidence of metal contamination. ^ Fine metal particles (traces of metal flakes/gray color to fluid ) are found in the converter. This is not harmful to the torque converter. ^ The vehicle has been exposed to high mileage. ^ A small amount of wear appears on the hub where the oil pump drive gear mates to the converter (RWD only). A certain amount of such wear is normal for both the hub and oil pump gear. Neither the converter nor the front pump assembly should be replaced. The torque converter should be replaced under any of the following conditions: ^ The vehicle has TCC shudder and/or no TCC apply. First complete all electrical and hydraulic diagnosis and check for proper engine operation. The converter clutch may be damaged. Also the converter bushing and/or internal 0-ring may be damaged. ^ Evidence of damage to the oil pump assembly pump shaft turbine shaft drive sprocket support and bearing or metal chips/debris in the converter. ^ Metal chips/debris are found in the converter or when flushing the cooler and the cooler lines. ^ External leaks in the hub weld area lug weld or closure weld. ^ Converter pilot is broken damaged or fits poorly into the crankshaft. ^ The converter hub is scored or damaged. ^ The transmission oil is contaminated with engine coolant engine oil or water. ^ If excessive end play is found after measuring the converter for proper end play (refer to Service Manual). ^ If metal chips/debris are found in the fluid filter or on the magnet and no internal parts in the unit are worn or damaged. This indicates that the material came from the converter. ^ The converter has an unbalanced condition that results in a vibration that cannot be corrected by following Converter Vibration Procedures. ^ Blue converter or dark circular ring between lugs. This condition will also require a complete cleaning of the cooler and a check for adequate flow Page 3741 PROM - Programmable Read Only Memory: Application and ID Footnotes 201 Thru 250 [201] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [202] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [203] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [204] Cold engine extended crank. USE 16181871 (SCAN I.D. = 0864) FOR COLD START STALL. USE 16181867 (SCAN I.D. = 0854) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [205] Cold engine extended crank. USE 16181871 (SCAN I.D. = 0864) FOR COLD START STALL. USE 16181867 (SCAN I.D. = 0854) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [206] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [207] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [208] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [209] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [210] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [211] Engine stall, long cranks/idle/decel/surge. CANNOT BE USED ON VEHICLES THAT DO NOT HAVE DIGITAL EGR VALVES. [212] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [213] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [214] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [215] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [216] Cold start extended crank. Engine starts with ignition key cycled. USE 16181883 (SCAN I.D. = 0894) FOR COLD START STALL. USE 16181875 (SCAN I.D. = 0874) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [217] Cold start extended crank, engine starts with ignition key cycled. USE 16181883 (SCAN I.D. = 0894) FOR COLD START STALL. USE 16181875 (SCAN I.D. = 0874) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [218] Cold engine extended crank. USE 16181887 (SCAN I.D. = 0904) FOR COLD START STALL. USE 16181879 (SCAN I.D. = 0884) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [219] Cold engine extended crank. USE 16181887 (SCAN I.D. = 0904) FOR COLD START STALL. USE 16181879 (SCAN I.D. = 0884) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [220] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [221] Surge or chuggle on decel and/or rough idle. PROM CAN ONLY BE USED WITH ECM P/N 16144288. Page 2435 Diagnostic Circuit Circuit Description The diagnostic circuit check is an organized approach to identifying a problem created by an electronic engine control system malfunction. It must be the starting point for any driveability complaint diagnosis, because it directs the service technician to the next logical step in diagnosing the complaint. Understanding the chart and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of good parts. Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. This step is a check for the proper operation of the "Service Engine Soon" light. The "SES" light should be "ON" steady. 2. No "SES" light at this point indicates that there is a problem with the "SES" light circuit or the control module control of that circuit. 3. This test checks the ability of the control module to control the "SES" light. With the diagnostic terminal grounded, the "SES" light should flash a Code 12 three times, followed by any trouble code stored in memory. A PROM error may result in the inability to flash Code 12. 4. Most of the diagnostic charts use a Tech 1 to aid diagnosis, therefore, serial data must be available. If a PROM error is present, the control module may have been able to flash Code 12 or 51, but not transmit serial data. 5. Although the control module is powered up, a "Cranks But Will Not Run" symptom could exist because of an control module or system problem. 6. This step will isolate if the customer complaint is a "SES" light or a driveability problem with no "SES" light. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions for a list of valid codes. An invalid code may be the result of a faulty "Scan" tool, PROM or control module. 7. Comparison of actual control system data with the typical valves is a quick check to determine if any parameter is not within limits. Keep in mind that a base engine problem (i.e., advanced cam timing) may substantially alter sensor values. 8. If the actual data is not within the typical values established, refer to individual component tests. Page 3502 CMFI Intake Manifold Sensors/Valves Page 476 Oil Pressure Sender: Locations Engine Sensor Locations. Top Rear Of Engine Applicable to: Except 4.3L/V6-262 HP & 4.3L/V6-262 Turbo Engines Page 4965 Symbol Identification Page 4568 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Locations EGR Valve Position Sensor: Locations Engine Wiring, LH Side Specifications Evaporator Case: Specifications Evaporator Case Mounting Bolt .............................................................................................................................................................. 3 Nm (27 in. lbs.). Evaporator Case Mounting Nut ........................................................................................................... .................................................... 2 Nm (18 in. lbs.). Page 8408 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Locations Turn And Hazard Lamp Flashers Fuel - Reformulated/Oxygenated Gasolines Fuel: All Technical Service Bulletins Fuel - Reformulated/Oxygenated Gasolines FILE IN SECTION: 0 - General Information BULLETIN NO.: 57-01-02 DATE: June, 1995 SUBJECT: Reformulated Gasoline (RFG), Oxygenated Gasoline and California Phase 2 RFG MODELS: 1995 and Prior Passenger Cars and Trucks General Motors customers will be potentially exposed to a variety of different fuel types. Besides the conventional gasoline available, new types such as Reformulated Gasoline (RFG), oxygenated gasoline, and starting in 1996, California Phase 2 RFG. Reformulated Gasoline (RFG) is blended to burn more cleanly and not to evaporate as readily. RFG must contain a minimum of 2 percent oxygen, which is usually achieved with ethanol or EPA-approved ethers such as methyl tertiary-butyl ether (MTBE). This type of fuel is required by the Clean Air Act in the nine worst ozone non-attainment areas of the country, and may also be required in other areas designated ozone non-attainment, at the option of the states. RFG is intended to produce approximately 15 percent less pollution than conventional gasoline. Using RFG should reduce the total health risk to the public by reducing exposure to ozone and air toxins. General Motors supports the use of RFG as a cost effective means of providing air quality benefits. Oxygenated gasolines are prevalent in the wintertime for Carbon Monoxide (CO) non-attainment areas. These fuels contain oxygen components similar to RFG. Approximately 50 percent of the fuel sold in the U.S. in the wintertime contains an oxygenate component. Vehicle fuel economy may be slightly reduced, if at all, by the use of gasoline containing oxygenates. Fuel economy is most affected by engine and vehicle type, driving habits, weather conditions, and vehicle maintenance. Properly blended RFG, oxygenated gasoline, and California Phase 2 RFG will have no adverse effect on vehicle performance or to the durability of engine and fuel system components. In fact, the General Motors Owner's Manual fuel statements have consistently permitted the use of properly blended fuels containing up to 10 percent ethanol (since 1980) and up to 15 percent methyl tertiary-butyl ether (MTBE) for current and all past model year vehicles. These statements continue to be valid. The use of oxygenate-containing fuels will not invalidate the GM vehicle warranty. Page 6917 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Testing and Inspection Brake Shoe: Testing and Inspection Inspect brake linings for excessive wear, damage, oil, grease or brake fluid contamination. If any of the above conditions exists, brake linings must be replaced. Brake shoes must always be replaced as an axle set to maintain equal braking forces. Examine brake shoe webbing, hold-down and return springs for signs of overheating indicated by a slight blue color. If any component exhibits signs of overheating, replace hold-down and return springs with new ones. Overheated springs lose their pull and could cause brake linings to wear out prematurely. Inspect all springs for sags, bends and external damage, and replace as necessary. Inspect hold-down retainers and pins for bends, rust and corrosion. If any of the above conditions exist, replace retainers and pins. Page 7456 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 4601 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 6570 Fuel Gage Is Inaccurate Oil Pressure Gage Indicates High Pressure At All Times Oil Pressure Gage Indicates Low Pressure When Oil Pressure Is Good Oil Pressure Gage Is Inaccurate Temperature Gage Is Inaccurate Page 7517 Symbol Identification Two Wheel Drive - 2WD Wheel Bearing: Adjustments Two Wheel Drive - 2WD FRONT WHEEL BEARINGS ADJUSTMENT 4 X 2 MODELS 1. Raise and support front of vehicle. 2. Remove hub dust cover, then the cotter pin. 3. While rotating wheel assembly in forward direction, torque spindle nut to specification to fully seat the bearings. 4. Loosen nut to the ``just loose'' position, then tighten the spindle nut finger tight. 5. If either spindle hole does not line up with a spindle nut slot, back off spindle nut not more than 1/2 nut flat. 6. Install new cotter pin, then measure hub endplay. Endplay should be .001-.005 inches when properly adjusted. 7. Install hub dust cover and lower vehicle. 4 X 4 MODELS These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Page 6840 For vehicles repaired under the terms of this special coverage, submit a claim with the information shown. Customer Reimbursement All customer requests for reimbursement for previous repairs for the special coverage condition will be handled by the Customer Assistance Center, not by dealers. Disclaimer Page 7735 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). A/C - Retrofitting R-12 Vehicles to R-134A Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Locations Engine Wiring, LH Side Page 6269 Compressor Clutch Diode HVAC: Locations Inside Compressor Clutch Connector Page 6249 Compressor Shaft Seal: Service and Repair With V5 Compressor Remove or Disconnect 1. Recover refrigerant. 2. Loosen and reposition compressor in mounting brackets. 3. Remove clutch plate and hub assembly from compressor as described in minor repairs. Removing Or Installing Shaft Seal Retaining Ring 4. Remove the shaft seal retainer ring, using snap ring pliers J 5403. 5. Thoroughly clean inside of compressor neck area surrounding the shaft, the exposed portion of the seal, the shaft itself and O-ring groove. Any dirt or foreign material getting into compressor may cause damage. A/T - Intermittent Slip, Downshift, or Busy Cycling TCC Torque Converter Clutch: Customer Interest A/T - Intermittent Slip, Downshift, or Busy Cycling TCC Number: 92-42-7A Section: 7A Date: NOV. 1991 Corporate Bulletin No.: 167105 ASE No.: A2 Subject: INTERMITTENT TRANSMISSION DOWNSHIFT, SLIP OR BUSY/CYCLING TCC Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSMISSION Some owners may comment that their vehicle is experiencing one or more of the following transmission conditions: - Intermittent slipping. - Intermittent downshift followed by an upshift, both with no apparent reason. - Busyness or cycling of the TCC at steady throttle conditions and level roadway. The cooling fan operates when the thermostat on the fan clutch reaches a preset temperature. When this temperature is reached, the fan engages to draw additional air through the radiator and lower the engine temperature. When the cooling fan engages, noise increases and may sound very similar to an increase in engine RPM due to transmission downshift, slipping or TCC cycling. When engine temperature lowers to a preset point the fan clutch will disengage. When the cooling fan disengages, noise levels will decrease and may sound very similar to a decrease in engine RPM. The type of concern described above requires further definition and the customer should be asked several questions: - Is the situation more pronounced at higher vehicle loads or pulling a trailer? - Do warmer ambient temperatures make the situation more pronounced as well? If the customer's responses indicate that both of these conditions apply, and your observation of the vehicle confirms a properly operating vehicle, provide the customer the vehicle operating description included in this bulletin. Further action may not be necessary. A service procedure follows if further definition is required. SERVICE PROCEDURE: When attempting to diagnose an intermittent transmission downshift, slip or busy/cycling TCC: 1. Check fluid level and condition as outlined in section 7A of the appropriate service manual. 2. Test drive the vehicle under the conditions described by the customer (ambient temperature, engine coolant temperature, trailering, etc.). It may be necessary to partially restrict airflow to the radiator to raise engine coolant temperature to match customer conditions. 3. Monitor engine RPM and engine coolant temperature using a scan tool. 4. Listen for an apparent increase in engine RPM. If engine RPM sounds like it increases, check the scan tool RPM and coolant temperature readings. If the noise increase is due to engagement of the fan the engine RPM will not increase and engine coolant temperature will begin to decrease after the fan engages. As the fan runs the engine coolant temperature will drop and the fan will disengage reducing noise levels, engine RPM will not decrease. This cycle will repeat as engine coolant temperature again rises. If the above procedure shows the condition to be cooling fan related, no further action is necessary. The vehicle should be returned to the customer and the condition explained. If the above procedure shows the condition to be other than cooling fan related, refer to section 7A of the appropriate service manual for transmission diagnosis information. Intermittent Transmission Downshift All light duty trucks are equipped with a thermostatic engine cooling fan. This fan is designed to provide greater fuel efficiency and quieter operation Page 1971 Oil Pressure Warning Lamp/Indicator: Testing and Inspection On some models, the oil pressure indicator light also serves as the electric choke defect indicator. If Oil or ENG. indicator light does not light, check to ensure electric choke is not disconnected at carburetor. Also check for defect in electric choke heater, blown gauge fuse or defect in lamp or wiring circuit. If indicator light stays on with engine running possible causes are: low oil pressure, switch to indicator light open circuit, disconnected oil pressure switch connector or oil pressure gauge or radio fuse has blown. The oil pressure warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on, replace the bulb. If the warning light goes on when the wire is grounded, check the engine unit for a poor ground, or improper installation. (The presence of sealing compound on the threads of the engine unit will cause a poor ground.) If the unit is found to be properly grounded and installed, replace the unit. If the warning light remains lit when it normally should be out, replace the engine unit before proceeding to determine the cause for low pressure indication. The warning light will sometimes light or flicker when the engine is idling, even if oil pressure is adequate. However, the light should go out when the engine speed is increased. Aluminum Wheels - Cosmetic Damage During Balancing Wheels: All Technical Service Bulletins Aluminum Wheels - Cosmetic Damage During Balancing Number: 93-197-3E Section: 3E Date: MAY 1993 Corporate Bulletin No.: 393502 ASE No.: A4 Subject: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING Model and Year: 1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V 1990-93 LUMINA APV Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Page 4462 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Page 747 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Symptom Related Diagnostic Procedures Fan Clutch: Symptom Related Diagnostic Procedures Clutch Fluid Leak Small fluid leaks do not generally affect the operation of the unit. These leaks generally occur around the area of the bearing assembly, but if the leaks appear to be excessive, engine overheating may occur. Clutch and fan free-wheeling can cause overheating. To check for clutch and fan free-wheeling, turn the motor "OFF." Spin the fan and clutch assembly by hand. If the fan spins five or more times before it stops, replace the clutch. Fan Clutch Noise Fan clutch noise can sometimes be noticed when clutch is engaged for maximum cooling. Clutch noise is also noticeable within the first few minutes after starting engine while clutch is redistributing the silicone fluid back to its normal, disengaged operating condition after settling for long periods of time (overnight). However, continuous fan noise or an excessive roar indicates the clutch assembly is locked-up due to internal failure. This condition can be checked by attempting to manually rotate fan. If fan cannot be rotated manually or there is a rough, abrasive feel as fan is rotated, the clutch should be replaced. Fan Looseness Lateral movement can be observed at the fan blade tip under various temperature conditions because of the type bearing used. This movement should not exceed 1/4 inch (6.5 mm) as measured at the fan tip. If this lateral movement does not exceed specifications, there is no cause for replacement. Page 6604 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Interior Door Handle Spring - Early Breakage Front Door Interior Handle: All Technical Service Bulletins Interior Door Handle Spring - Early Breakage Group Ref.: Body Bulletin No.: 461601 Date: April, 1994 INFORMATION SUBJECT: INTERIOR DOOR HANDLE SPRING BREAKAGE MODELS: 1990-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1990-94 CHEVROLET AND GMC TRUCK S/T UTILITIES 1991-94 OLDSMOBILE BRAVADA Some vehicles may be found to have front side door interior door handles with broken springs. This condition tends to be associated with vehicles that experience high (frequent) usage of the door handle mechanism. To enhance spring durability, production vehicles are now receiving door handle assemblies with lithium grease added to the spring. The durability of replacement door handles obtained from GMSPO can be increased by adding lithium based lubricant to the door handle spring. The lubricant should be applied so that it works into and between the spring coils. This will allow the coils to move past each other freely, reducing spring breakage. SERVICE PARTS INFORMATION: P/N Description Qty Procure Locally Lithium Based As Needed Lubricant Page 7189 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 303 Figure 7 Figure 8 Figure 9 Figure 10 Page 4730 Brake Bleeding: Technical Service Bulletins Brake Pressure Modulator Valve - Bleed Procedure Number: 93-12-5 Section: 5 Date: SEPT. 1992 Corporate Bulletin No.: 263003R ASE No: A5 Subject: REVISED BRAKE PRESSURE MODULATOR VALVE (BPMV) BLEED PROCEDURE Model and Year: 1990-93 LIGHT DUTY TRUCKS WITH 4WAL SERVICE UPDATE The brake pressure modulator valve (BPMV) (formerly called the EHCU) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves (item A, figure 1) 1/4 to 1/2 turn before bleeding. Should the BPMV need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTE: The ignition switch must be in the "OFF" position or false diagnostic trouble codes could be set to memory. Tools Required: J 39177 Combination Valve Pressure Bleeding Tool (Three Required) TK 00000 Tech-1 Scan Tool TK 02650 RWAU4WAL Cartridge Kit IMPORTANT You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV (figure 1). 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV (figure 1). Page 5545 available, measurements may also be clearly and legibly handwritten into the Wheel Alignment Repair Order Questionnaire attached to this bulletin. 4. Attach the Wheel Alignment Repair Order Questionnaire below along with the print-out of "Before" and "After" wheel alignment measurements to the Repair Order and retain for use by GM. Wheel Alignment Equipment and Process Wheel alignments must be performed with a quality machine that will give accurate results when performing checks. "External Reference" (image-based camera technology) is preferred. Please refer to Corporate Bulletin Number 05-00-89-029B: General Motors Dealership Critical Equipment Requirements and Recommendations. Requirements: - Computerized four wheel alignment system. - Computer capable of printing before and after alignment reports. - Computer capable of time and date stamp printout. - Racking system must have jacking capability - Racking system must be capable of level to 1.6 mm (1/16 in) - Appropriate wheel stops and safety certification - Built-in turn plates and slip plates - Wheel clamps capable of attaching to 20" or larger wheels - Racking capable of accepting any GM passenger car or light duty truck - Operator properly trained and ASE-certified (U.S. only) in wheel alignment Recommendations: Racking should have front and rear jacking capability. Equipment Maintenance and Calibration: Alignment machines must be regularly calibrated in order to give correct information. Most manufacturers recommend the following: - Alignment machines with "internal reference" sensors should be checked (and calibrated, if necessary) every six months. - Alignment machines with "external reference" (image-based camera technology) should be checked (and calibrated, if necessary) once a year. - Racks must be kept level to within 1.6 mm (1/16 in). - If any instrument that is part of the alignment machine is dropped or damaged in some way, check the calibration immediately. Check with the manufacturer of your specific equipment for their recommended service/calibration schedule. Wheel Alignment Process When performing wheel alignment measurement and/or adjustment, the following steps should be taken: Preliminary Steps: 1. Verify that the vehicle has a full tank of fuel (compensate as necessary). 2. Inspect the wheels and the tires for damage. 3. Inspect the tires for the proper inflation and irregular tire wear. 4. Inspect the wheel bearings for excessive play. 5. Inspect all suspension and steering parts for looseness, wear, or damage. 6. Inspect the steering wheel for excessive drag or poor return due to stiff or rusted linkage or suspension components. 7. Inspect the vehicle trim height. 8. Compensate for frame angle on targeted vehicles (refer to Wheel Alignment Specifications in SI). Satisfactory vehicle operation may occur over a wide range of alignment angles. However, if the wheel alignment angles are not within the range of specifications, adjust the wheel alignment to the specifications. Refer to Wheel Alignment Specifications in SI. Give consideration to excess loads, such as tool boxes, sample cases, etc. Follow the wheel alignment equipment manufacturer's instructions. Measure/Adjust: Important Prior to making any adjustments to wheel alignment on a vehicle, technicians must verify that the wheel alignment specifications loaded into their wheel alignment machine are up-to-date by comparing these to the wheel alignment specifications for the appropriate model and model year in SI. Using incorrect and/or outdated specifications may result in unnecessary adjustments, irregular and/or premature tire wear and repeat customer concerns Page 1066 Clutch Fluid: Fluid Type Specifications Hydraulic Clutch Fluid ........................................................................................................................................................... DOT 3 or DOT 4 Brake Fluid Page 6762 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Cooling - Cold Start Fan Noise Fan Clutch: Customer Interest Cooling - Cold Start Fan Noise BULLETIN NUMBER: 92-66-56A SECTION: 6B Engine Cooling NUMBER: 2 CORPORATE REFERENCE NUMBER: 1662O3R DATE: May 1993 SUBJECT: COLD START FAN NOISE (INSTALL REVISED "QUICK DUMP" FAN CLUTCH) MODELS: 1987-92 M-VANS WITH 4.3L ENGINE 1990-92 L-VANS WITH 4.3L ENGINE 1988-92 S/T TRUCKS WITH 4.3L ENGINE THIS BULLETIN CANCELS AND REPLACES GMC TRUCK BULLETIN 92-6B-56. IT IS BEING REVISED TO INCLUDE M/L VANS, AND TO SERVICE PARTS INFORMATION AND RPO DEFINITIONS. ALL COPIES OF 92-6B-56 SHOULD BE DISCARDED. CONDITION Some owners of 1987-92 M-vans, 1990-92 L-vans, and 1988-92 S/T vehicles with a 4.3L engine (RPO LB4, LU2, or L35) and air conditioning (RPO C60) may experience higher than normal fan noise upon cold start up (usually fan noise extended beyond 90 seconds after start up). CAUSE This condition may be due to an extended engagement of the fan clutch. CORRECTION The condition may be corrected by installing a revised fan clutch which reduces the fan clutch engagement cycle. Vehicles built after the following VIN breakpoints have the new fan clutch installed in production: Plant VIN Moraine N2514836 Shreveport N8512403 Pontiac West N0508347 Baltimore NB534465 SERVICE PROCEDURE Refer to section 6B1 "FAN CLUTCH REPLACEMENT" in the appropriate Service Manual for removal and installation of the fan clutch. Page 8344 Symbol Identification Page 57 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 4968 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) IP Dimmer Control - Proper Setting Instrument Cluster / Carrier: All Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Page 7476 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 6882 1. With the end gate open, use a grease pencil to mark around the circumference of each washer (Figure 1, "7") located behind the strikers. 2. Unscrew and remove the existing striker assemblies (Figure 1, "6") from the vehicle. 3. Loosely assemble the new striker (Figure 1, "6") (P/N 15700881) and washer (Figure 1, "7") and reinstall using the pencil marks as a guide. 4. Install the striker assemblies (Figure 1, "6") using a T50 Torx(R). Torque to 63 N-m. (47 lbs.ft.). 5. Check for proper operation and end gate flushness. Adjust the striker assemblies if required. The end gate lock strikers can be adjusted up or down, fore or aft, to obtain proper closure of the end gate. The end gate should seal completely with minimum closing effort. Torque the striker bolts to 63 N-m. (47 lbs.ft.). SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY/VEH 15700881 Striker Asm. 2 Page 336 Clutch Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Specifications Accumulator HVAC: Specifications Evaporator-to-Accumulator .................................................................................................................. ................................................. 41 Nm (30 ft. lbs.). Refrigerant Hose-to-Accumulator .......................................................................................................................................................... 41 Nm (30 ft. lbs.). Specifications Intake Air Temperature Sensor: Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Page 1921 the engine block and intake manifold. See Figures 1 and 2. Wacker T-330 RTV has improved adhesive abilities, is oxygen sensor safe, and is noncorrosive to ferrous metals. Wacker T-330 RW cannot be used in coolant sealing surface areas. Page 4622 NOTICE: When performing the 4WAL brake system bleeding procedure, the ignition switch must be in the "OFF" position or false diagnostic trouble codes could be set to memory. If trouble codes are set, refer to section 5El "Clearing Diagnostic Trouble Codes" in the 1993 Service Manual. Pressure Bleed Procedure The pressure bleeding equipment must be of the diaphragm type. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. IMPORTANT: You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Begin by attaching the pressure bleeder adaptor J29567 to the master cylinder (figure 1). 2. Fill the pressure bleeder tank J29532 at least 2/3 full with Delco Supreme No. 11 Hydraulic Brake Fluid (GM P/ N 1052535) or an equivalent DOT 3 motor vehicle brake fluid. The bleeder tank must be bled each time brake fluid is added. 3. Charge the bleeder tank to 140-170 kPa (20-25 psi) and connect the hose from the bleeder tank to the bleeder adaptor. Page 8320 Map Light: Description and Operation ILLUMINATED LEFT AND RIGHT VANITY MIRRORS Voltage for the illuminated vanity mirrors is supplied through the HORN-DM Fuse which is hot at all times. When the mirror cover is opened, the switch closes and the ground path is completed to the visor attaching screws. By moving the HI/LO selector switch on the mirror, the lamp intensity can be changed. REARVIEW MIRROR MAP/READING LIGHT Voltage for the map/reading light is supplied by the RADIO fuse. When the ON/OFF selector switch is closed, the ground path is completed and the lamp illuminates. Page 6027 Page 6163 3. Install Rotor and Bearing Puller Guide J 25031 to the front head and install Puller J 8433 with Poly-V-Belt Puller Leg Set J 24092 and remove the clutch coil from the front head (Fig. 25). Clutch coil may also be removed by using rotor and bearing puller guide J 25031 with puller tool J 25287 (Fig. 26). Install or Connect 1. Place the clutch coil assembly on the neck of the front head with clutch coil terminals in line with mark described in Step 2 of the removal procedure. Locations Audio Alarm Module: Locations On Convenience Center Page 4916 Wheel Speed Sensor: Service and Repair Rear Wheel Speed Sensor Fig. 58 Rear Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Remove brake drum. 3. Remove primary brake shoe. 4. Disconnect sensor electrical connector. 5. Remove sensor wire from rear axle clip. 6. Remove speed sensor attaching bolts, Fig. 58, then remove sensor by pulling wire through hole in backing plate. 7. Reverse procedure to install. Torque speed sensor attaching bolts to 26 ft. lbs. Page 6600 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 5457 Symbol Identification Page 8361 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Wheels/Tires - Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Page 4950 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 8269 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 4282 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure that pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. When endplay is reduced to zero, check pinion bearing preload by rotating pinion with suitable torque wrench. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Service and Repair Blower Motor Switch: Service and Repair Wiring Harness Installation Control Assembly Page 7576 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice SIR - Operating Vehicle with Warning Light On Malfunction Lamp / Indicator: All Technical Service Bulletins SIR - Operating Vehicle with Warning Light On File In Section: 8 - Chassis/Body Electrical Bulletin No.: 83-81-34 Date: March, 1999 INFORMATION Subject: Operating Vehicle with Supplemental Inflatable Restraint (SIR) Warning Light Illuminated Models: 1999 and Prior Passenger Cars and Light Duty Trucks with SDM Controlled Air Bag System The AIR BAG warning light is the key to driver notification of Supplemental Inflatable Restraint (SIR) system malfunctions. When the warning light remains illuminated or continues to flash, one or more of the following conditions may occur if vehicle operation is continued. ^ Non-deployment of the air bags in the event of a crash. ^ Deployment of the air bags without a crash. ^ Deployment of the air bags in crashes less severe than intended. If an AIR BAG warning light is illuminated or flashing, you should advise the customer of these possibilities and that the vehicle should be serviced right away. Page 7529 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 1435 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Page 5205 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 5692 The patented wheel has three sets of energy absorbing components: the hub, spokes and rim. The hub consists of six formed metal "legs" which are calibrated to limit the rigidity of the steering wheel structure. The limit is based on human injury tolerance data that was obtained through GM Research Labs. Like the hub at the center of the steering wheel, the wheel's three or four spokes (depending on the model) and rim are also energy absorbing. They have metal rods contoured to "give" when occupants impact the steering wheel from various angles. Briefly stated, the design of the wheel assembly is rigid enough for daily use yet flexible and dynamic enough to help absorb the energy of the driver's forward movement in a frontal collision. Vehicles with Supplemental Inflatable Restraint Systems (SIR) do not have self-aligning steering wheels since the SIR provides similar protection in frontal impacts. It is important to remember that the steering system safety features found on today's vehicles are NOT designed to be a convenient substitute for safety belts. To protect all occupants of a vehicle, safety belts must be worn at all times. If you are involved in repairs on a 1992 J car or T truck that has been in a front end collision, replace the steering wheel if it shows any signs of distortion. Page 4286 Pinion Bearing: Service and Repair Borg Warner - 2 Pinion 1. Scribe reference mark between drive pinion and driveshaft yoke, then hold yoke with suitable tool and remove pinion nut and yoke. If yoke shows wear in the seal-to-flange contacting surface, the yoke should be replaced. 2. Install original pinion nut a few turns on pinion shaft, then using hammer and drift, tap pinion shaft out of pinion housing. Hold gear end of pinion shaft when removing to prevent it from falling from axle housing. On Corvette models, the pinion preload shims may stick to the pinion housing or the rear bearing during removal. These shims must be collected and kept together for use during reassembly. 3. Remove and discard pinion nut and collapsible spacer. 4. If being replaced, remove front and rear bearing races from pinion housing using drift positioned in race slots and hammer. 5. If rear pinion bearing is being replaced, remove using arbor press and adapters. Measure and record thickness of shim which is found under rear bearing. Page 5437 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 3873 Page 8566 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 5324 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 7845 Page 6155 5. Place the Rotor and Bearing assembly on blocks as shown in Figure 11. Drive the bearing out of the rotor hub with Rotor Bearing Remover J 9398-A. It is not necessary to remove the staking at the rear of the rotor hub to remove the bearing. However, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore, or the bearing may be damaged (Fig. 12). Install or Connect 1. Place the Rotor and Hub assembly face down on a clean, flat and firm surface. 2. Align the new bearing squarely with the hub bore and using Pulley and Bearing Installer J 9481-A with Universal Handle J 29886, drive the bearing fully into the hub (Fig. 13). The Installer will apply force to the outer race of the bearing if used as shown. Locations Horn Switch: Locations Part Of Multi-Function Switch Page 7035 Time Allowance: See Chants NOTE: The time allowances provided on the chart include the hardware removal and installation (as indicated by the list guidelines), the masking and unmasking of the vehicle, stripping of the surface (as indicated by the guidelines), the refinish (and colorcoat when required), mix time for primer/ paint (and clearcoat when required), finesse/polish where required, washing and preparing the vehicle for delivery. OPERATION DESCRIPTION: PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER, REFINISH ENTIRE BODY ABOVE BODY SIDE MOLDINGS. PAINT TERM DEFINITIONS Following are definitions of paint repair terms used in this bulletin: Basecoat: A color topcoat that requires a clear topcoat over it. Break line: A natural dividing line on Page 8258 Symbol Identification Service and Repair Flex Plate: Service and Repair 1. Disconnect battery ground cable. 2. Remove air cleaner assembly. 3. Disconnect TV cable at its upper end. 4. Raise and support vehicle. 5. Remove propeller shaft from vehicle. 6. Disconnect speedometer cable, shift linkage assembly and electrical connectors from transmission. 7. Remove transmission support brace attaching bolts from converter cover, if equipped. 8. Remove converter cover, then mark flywheel and torque converter for installation. 9. Remove exhaust crossover pipe and catalytic converter attaching bolts from vehicle. 10. Remove torque converter to flywheel bolts and/or nuts. 11. Disconnect catalytic converter support bracket. 12. Position a suitable jack under transmission and raise slightly. 13. Remove transmission crossmember to transmission mount bolt. 14. Remove transmission crossmember to frame bolts and/or insulators, if equipped. 15. Slide crossmember rearward and remove from vehicle. 16. Lower transmission. 17. Disconnect and cap transmission fluid cooler lines. 18. Disconnect TV cable from transmission. 19. Position a suitable jack under engine, then remove transmission to engine attaching bolts. 20. Carefully separate transmission from engine. Install torque converter holding tool No. J-21366. 21. Remove transmission from vehicle. 22. To install transmission, reverse removal procedure. Interior - Proper Use of Floor Mats Carpet: Technical Service Bulletins Interior - Proper Use of Floor Mats INFORMATION Bulletin No.: 10-08-110-001 Date: March 30, 2010 Subject: Information on Proper Use of Floor Mats Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2003-2009 HUMMER H2 2006-2010 HUMMER H3, H3T 2005-2009 Saab 9-7X GM's carpeted and all-weather (rubber) floor mats are especially designed for use in specific GM vehicles. Using floor mats that were not designed for the specific vehicle or using them incorrectly may cause interference with the accelerator or brake pedal. Please review the following safety guidelines regarding proper driver's side floor mat usage with the customer. Warning If a floor mat is the wrong size or is not properly installed, it can interfere with the accelerator pedal and/or brake pedal. Interference with the pedals can cause unintended acceleration and/or increased stopping distance which can cause a crash and injury. Make sure the floor mat does not interfere with the accelerator or brake pedal. - Do not flip the driver's floor mat over (in an effort to keep the floor mat clean) - Do not place anything on top of the driver's floor mat (e.g. carpet remnant, towel) - Do not place another mat on top of the driver's floor mat (e.g. do not place all-weather rubber mats over carpeted floor mats) - Only use floor mats that are designed specifically for your vehicle - When using replacement mats, make certain the mats do not interfere with the accelerator or brake pedal before driving the vehicle If your vehicle is equipped with a floor mat retaining pin(s) or clip(s), make certain the mat is installed correctly and according to the instructions. Constant Velocity Type Universal Joint: Service and Repair Constant Velocity Type Disassembly and Assembly Fig. 10 Constant Velocity (CV) Universal Joint This type of universal joint, Fig. 10, consists of two conventional cross and roller joints connected with a special link yoke. Because the two joint angles are the same, even though the usual universal joint fluctuation is present within the unit, the acceleration of the front joint (within the yoke) is always neutralized by the deceleration of the rear joint (within the yoke) and vice versa. The end result is the front and rear propeller shafts always turn at a constant velocity. Fig. 1 Production Type Universal Joints Which Use Nylon Injection Rings In Place Of Snap Rings Fig. 2 Service Type Universal Joints (Internal Snap Ring Type) Before disassembling any universal joint, examine the assembly carefully and note the position of the grease fitting (if used). Also, be sure to mark the yokes with relation to the propeller shaft so they may be reassembled in the same relative position. Failure to observe these precautions may produce rough vehicle operation which results in rapid wear and failure of parts, and place an unbalanced load on transmission, engine and rear axle. When universal joints are disassembled for lubrication or inspection, and the old parts are to be reinstalled, special care must be exercised to avoid damage to universal joint spider or cross and bearing cups. Some driveshafts use an injected nylon retainer to hold the bearing cups. When service is necessary, pressing the cups out will sheer the nylon retainer, Page 2489 EGR AND EVRV SOLENOID 4.3 L Page 465 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Locations Oil Pressure Switch (For Fuel Pump): Locations Rear Of Engine Oil Pressure Switch 4.3L Utility Rocker Arm Nut Torque Rocker Arm Assembly: Specifications Rocker Arm Nut Torque VALVE ROCKER ARM NUT TORQUE Valve Rocker Arm Nuts ....................................................................................................................... ................................................ 27 Nm (20 lb. ft.). Page 7610 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 6253 Fully engage the knurled tangs of Seal Remover-Installer J 23128-A into the recessed portion of the Seal by turning the handle clockwise. Remove the Seal from the compressor with a rotary-pulling motion. Discard the Seal. The handle must be hand-tightened securely. Do not use a wrench or plier (Fig. 28). 7. Remove and discard the seal seat O-ring from the compressor, neck using O-ring Remover J 9553-1. 8. Recheck the shaft and inside of the compressor neck and O-ring groove for dirt or foreign material and be sure these areas are perfectly clean before installing new parts. Page 5586 Recall 93V008000: Engine Cooling Fan Blade Breaks Fan Blade: All Technical Service Bulletins Recall 93V008000: Engine Cooling Fan Blade Breaks The engine cooling fan blades break as a result of fatigue and/or vehicle induced stress. If the blade breakage occurs while the hood is open, a person working under the hood or in the vicinity of the vehicle could be struck and injured by the blade segment. Install a newly designed fan assembly. System: Engine. Vehicle description: Light trucks with 2.5L engines without air conditioning. Page 1048 - Apply rubber lubricant to the inside diameter of hose ends, If desired. - Slip a new hose clamp over one end of the hose and push the hose onto the heater pipe with a twisting motion. - Repeat the hose and clamp installation procedure at the other end of the hose. - Tighten clamp screw to 1.7 Nm (15 in. lb.). 4. Engine coolant. - Use the coolant drained earlier only if it is uncontaminated. Discard contaminated coolant and add fresh 50/50 coolant and water mixture. Inspect - Be sure the installed hose(s) do not sag or rub against other components. Adjust or support the hose as necessary to correct. - Operate the engine and check the hose installation for leaks. - Tighten the hose clamp screw a bit at a time, if necessary, to stop a leak. - Check the coolant level after the engine has been warmed up and allowed to cool. Add coolant as required. Page 3895 Page 3545 2.8L - Engine Distributor Components DELCO REMY DISTRIBUTORS Distributors with separate coils are used on light duty truck engines. The ignition coil connects to the distributor cap through a high tension wire. The distributor uses an internal magnetic pickup assembly that consists of a permanent magnet, pole piece with internal teeth, and pickup coil. When the rotating teeth of the timer core line up with the teeth of the pole piece, voltage is induced in the pickup coil. This voltage signals the ignition control module to trigger the primary ignition circuit. Current flow in the primary circuit is interrupted and a high voltage of up to 35,000 volts is induced in the ignition coil secondary winding. This high voltage is directed through the secondary ignition circuit to fire the spark plugs. The distributor used on the 2.8L engine uses a capacitor for radio noise suppression that is integral with the terminal block. IDENTIFICATION The part number (seven digits) is located on a label on the distributor cap. IGNITION CONTROL MODULE The ignition control module is a solid state unit containing many complete circuits. The circuits control spark triggering, switching, current limiting, dwell control, and distributor pickup. The vehicle's computer sends signals to the module to control dwell and spark timing. The module may have seven or eight terminals, depending on the ignition system. POLE PIECE AND COIL ASSEMBLY The pole piece and plate assembly (often referred to as the pickup coil assembly) located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. CAPACITOR The capacitor in the distributor is for radio noise suppression. Page 6645 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 3012 - Cruise control - ANTILOCK brake system. CONSTRUCTION The VSS is made up of: Permanent Magnet (PM) generator (coil), which is mounted on the transmission. - Rotor (tooth), which is mounted on the output shaft in the transmission. - VSS Buffer, which is mounted to the control module bracket. OPERATION The VSS is a Permanent Magnet (PM) generator that produces a pulsing Alternating Current (AC) voltage as each rotor tooth nears the coil. As the vehicle speed increases, the number of AC voltage pulses increase. The VSS buffer processes inputs from the VSS and outputs signal to the speedometer control module and cruise module. The VSS buffer takes the voltage pulses from the VSS and uses them to open and close four solid state output switches to ground at a rate proportional to vehicle speed. The VSS buffer is matched to the vehicle based on final drive ratio and tire size. Page 7057 panel(s) that can be used as a starting/ stopping point when making a repair. Clearcoat: A clear topcoat required to cover a color basecoat. DELAMINATION: Loss of adhesion between one coat of paint to succeeding coats or coatings. Ultraviolet DELAMINATION is between the E coat (ELPO) and color topcoat(s). ELPO: (Electrocoating or "E" coat): The process by which electrically charged primer is plated on conductive surfaces of an opposite charge. This process provides outstanding corrosion resistance. Guidecoat: A light coat (almost overspray) of color applied over primer surfacer prior to wetsanding to highlight any low spots. Insert Color: The secondary two-tone color between the break line and body side molding. Monocoat: A color topcoat that does not require a clearcoat. Primer: The coating applied to a properly prepared substrate (bare metal) to give adhesion, corrosion and chemical resistance. Primer Sealer: An undercoat that provides maximum adhesion. color coating and corrosion protection. Primer Surfacer: An undercoat used to fill imperfections, with primer qualities, that must be sanded. Refinish: The act of replacing a painted surface, usually undercoat and topcoat. Scuff Sand: A method of sanding a painted surface using a fine grit sandpaper to promote paint adhesion. Topcoat: A finish material over an undercoat material. Ultraviolet Light: The portion of the spectrum of light which can cause fading of paint. It is located below the visible part of the spectrum. V.O.C.: "Volatile Organic Compound" or "Volatile Organic Content" relates to certain emission requirements in specific areas of the country. Page 1157 Removal & Installation Distributor: Service and Repair Removal & Installation Distributor And Coil 4.3L Engine REMOVE/DISCONNECT NOTE Verify ignition switch is "OFF". 1. Wiring harness connectors at side of distributor. 2. Coil wire and sparkplug wires on either left or right side of distributor. 3. Distributor cap by two screws and set to side: - Bring engine to TDC on the compression stroke for #1 cylinder and align timing marks to 0~ . Scribe a mark on distributor housing in line with rotor. - Scribe a mark on engine in line with rotor. Note position of distributor housing in relation to engine. 4. Remove distributor bolt hold-down clamp, raise distributor noting rotor rotation, then remove distributor and gasket (if applicable). Do not rotate crankshaft with distributor removed from engine. INSTALL/CONNECT NOTE To ensure correct timing of distributor it must be installed with rotor correctly positioned as noted in Step 3 of the removal procedure. Line up rotor, mark on distributor housing, and mark on engine. If distributor shaft won't drop into engine, insert a screwdriver into cavity for distributor and turn oil pump driveshaft. 1. Distributor and gasket (if applicable). 2. Hold-down clamp and tighten bolt to 34 Nm (25 lb. ft.). 3. Distributor cap. 4. Wiring harness connectors at side of distributor. 5. Sparkplug wires and coil wires. 6. Check engine timing. IP Dimmer Control - Proper Setting Dimmer Switch: Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Page 5398 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 4991 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 5570 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Page 4395 Fig. 8 Removing Bearing Cup By Holding Cup In Vise & Striking Center Yoke With Hammer Disassembly 1. Place driveshaft in a vise using care to avoid damaging it. 2. Remove bearing cup retaining snap rings. Some universal joints use injected nylon retainers in place of snap rings. During servicing, the snap rings supplied with the replacement universal joint assembly must be used. 3. Mark relationship between yoke and shaft for assembly reference. 4. Position tool on shaft and press bearing cup out of yoke, Fig. 7. If the cup cannot be pressed all the way out, remove it using vise grips or channel lock pliers or position driveshaft as shown and strike center yoke with hammer, Fig. 8. 5. Reposition tool so that it presses on the spider in order to press other bearing cup from opposite side of flange. 6. Remove tool, then the flange from spider. Assembly 1. Start new bearing cup into yoke, then position spider into yoke and press cup until it is 1/4 inch below surface. 2. Remove tool and install a new snap ring. 3. Start new bearing cup in opposite side of yoke, then install tool and press until cup is fully seated. 4. Remove tool and install remaining snap ring. Page 73 Symbol Identification Page 350 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 7575 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 6295 inserted through the mode indicator. (Fig.3) 13. Torque the housing, baseplate and blower switch mounting screws to 6-10 lbs.in. 14. If necessary, install new knobs on mode, temperature, and blower controls to ensure proper retention. SERVICE PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: LABOR OPERATION DESCRIPTION D0362 R & R HVAC control ADD: Replace housing Use applicable labor time guide for labor hours. Page 6235 Shaft Key, Clutch Plate/Hub Installation 1. Install the shaft key into the hub key groove. Allow the key to project approximately 3.2mm (1/8") out of the keyway. The shaft key is curved slightly to provide an interference fit in the hub key groove. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the clutch plate and hub assembly. 3. Align the shaft key with the shaft keyway and place the clutch plate and the hub assembly onto the compressor shaft. Installing Clutch Plate & Hub Assembly 4. Remove the forcing tip on J 33013-B clutch plate and hub assembly installer-remover center screw and reverse the body direction on the center screw. Removing Pulley Rotor And Bearing Assembly 5. Install the clutch plate and hub installer-remover J 33013-B with bearing. The body of the J 33013-B installer-remover should be backed off sufficiently to allow the center screw to be threaded onto the end of the compressor shaft. 6. Hold the center screw with a wrench. Tighten the hex portion of the installer-remover J 33013-B body to press the hub onto the shaft. Tighten the body several turns, remove the installer and check to see that the shaft key is still in place in the keyway before installing the clutch plate and hub Page 4503 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 5733 - make sure parts positioning is correct (Figure 3). b. Install the link bolt (62) through the lower control arm hole (59) with the parts stacked properly (Figure 3). - Grommet (58) - Retainer (57) - Spacers (56) - Retainers (55) - Grommet (54) - Stabilizer (53) c. Attach the grommet (52), retainer (51) and nut (50) on the link bolt (62) (Figure 3) and tighten nut until the nut meets the end of the bolt threads (62) (Figure 3). 6. Install shock absorber (36) (Figure 2). a. Install retainer (35) and grommet (34) on the stem (33) (Figure 2). - Fully extend the stem (33). b. Install shock absorber (36) up through the lower control arm (40) and the spring (37). - Insert the stem (33) end through the hole in the upper control arm frame bracket (42) (Figure 2) c. Install the grommet (32), retainer (31), and the nut (30) on to the stem (33) (Figure 2). Tighten: Tighten bolt (38) to 27 N-m (20 lbs.ft.). SERVICE PARTS INFORMATION: Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Locations Engine Wiring, LH Side Engine - Miss, Hesitation, or Roughness Spark Plug Wire: Customer Interest Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 4245 Differential Clutch: Service and Repair 8 7/8 Inch Ring Gear Cam Gear Clutch If cam plate or clutch discs must be replaced, the cam gear subassembly must be serviced as follows: 1. Measure and record overall length of gear assembly (front face of gear to back side of thrust ring, including shim). This dimension will be needed to reassemble unit if thrust ring is replaced. Do not replace thrust ring unless necessary. If ring is excessively worn or scored, check bore in case for scoring. If bore is scored, replace entire differential. 2. With gear hub end up, compress disc pack and install jaws of split ring bearing remover between the thrust ring and the top eared disc. Bevel side of bearing remover should face up toward thrust ring. 3. Place cam gear assembly with bearing remover attached in an arbor press supporting the bearing remover on both sides. 4. Install a 1-1/2 inch to 1-3/4 inch diameter plug on gear hub. Press against plug with ram of press to remove thrust ring. Keep components in proper order. 5. Place gear on bench with hub end up. 6. Assemble cam plate with cam form down to mate with cam form on gear. Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 7. Assemble onto cam plate: 2 eared discs, 1 splined disc, and 1 wave spring alternately, Fig. 8. 8. Assemble onto gear hub: 2 splined discs and 3 eared discs alternately, Fig. 8. 9. Locate cam gear assembly in arbor press with hub end up. Place thrust ring on gear hub and press to shoulder making sure that ring is square with hub. Compress disc pack by pushing down on the discs to keep the splined discs from becoming wedged between the thrust ring and gear shoulder while pressing the subassembly together. Side Gear (RH) Clutch Body - TPO Fascia Cleaning Prior to Painting Paint: All Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer Locations Switch: Locations Anti-Lock Brake Components. In Front Axle Applicable to: 1992 Blazer & Jimmy Page 6558 a. One piece transceivers should be mounted under the dash, or on the transmission hump where they will not interfere with vehicle controls or passenger movement (See Figure 1 - One Piece Transceiver Installation). P/S - Reduced Assist When Cold Power Steering Fluid: Customer Interest P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Page 7968 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 2343 3. Transmission fluid cooler line fittings. Tighten Fittings to 27 N.m (20 ft. lbs.). 4. Hoses. 5. Upper fan shroud. 6. Coolant reservoir hose. 7. Coolant to the radiator. Page 313 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 4985 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 8675 Tool Required: J-21104 Trim Pad Remover. REMOVE OR DISCONNECT 1. Door pillar molding. 2. Window regulator handle. 3. Armrest. 4. Trim panel. Pry the fasteners from their seats using J-21104. INSTALL OR CONNECT 1. Trim panel to the door. 2. Armrest. 3. Window regulator handle 4. Door pillar molding. Window Regulator Handle Replacement Front Door Window Regulator Handle TOOL REQUIRED: J-9886-O1, Door Handle Remover. REMOVE OR DISCONNECT 1. Window regulator handle. ^ Insert J-9886-O1 between the handle and the bearing plate. ^ Align the tool parallel with the door handle, and push to disengage the clip. ^ Pull the handle from the door. 2. Bearing plate. INSTALL OR CONNECT 1. Bearing plate. 2. Window regulator handle. ^ Place the window in the raised position. ^ Put the clip onto the handle, ^ Insert the handle onto the door so the handle is pointing towards the front of the door. ^ Push on the handle until the clip engages the window regulator shaft. Window Regulator Replacement Spark Plugs - Revised Spark Plug: Technical Service Bulletins Spark Plugs - Revised Number: 93-03-6D Section: 6D Date: AUGUST 1992 Corporate Bulletin No.: 166001R ASE No.: Al, A6, A8 Subject: NEW DESIGN SPARK PLUGS Model and Yew: 1991-93 ALL PASSENGER CARS AND TRUCKS WITH GASOLINE ENGINES THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO., 91-234A-OB, DATED JULY 1992. THE 1992 AND 1993 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 91-234A-OB SHOULD BE DISCARDED. In 1991 GM introduced a new design spark plug for use in all trucks equipped with gas engines. These new design spark plugs have a ceramic insulator which is approximately 1/8 inch longer than the insulator used in previous model years. The longer length spark plugs, which conform to S.A.E. and I.S.O. Engineering guidelines, magnify the problem of cracked insulators because currently, most spark plug sockets are not of sufficient length to properly engage the shell hex. If the spark plug shell hex is not fully engaged in the spark plug socket wrench, the socket may cock at an angle and cause insulator cracking and/or breakage during plug installation or removal. When servicing these new design spark plugs, make sure that the spark plug socket being used is deep enough to accommodate the longer length insulator. The spark plug socket wrench should conform to the proposed S.A.E. and I.S.O. world standards for spark plug socket wrenches. Spark plug socket wrenches that conform to these standards are designed to accept the lengthened spark plugs and allow full engagement of the hex nut on the shell of the spark plug. Use of a spark plug socket which is NOT deep enough may result in the ceramic insulator becoming cracked above the spark plug shell. Note: SOME CRACKS IN THE INSULATOR M" NOT BE VISIBLE. SUCH CRACKS MAY LATER CAUSE A SPARK PLUG TO MISFIRE. SPARK PLUG MISFIRES ARE OFTEN MISDIAGNOSED AS A SLIPPING TRANSMISSION, DEFECTIVE TORQUE CONVERTER CLUTCH, ENGINE IMBALANCE, OR MALFUNCTIONING FUEL SYSTEM. To prevent insulator damage, it is recommended that the proper spark plug socket wrench be used when removing or replacing spark plugs. One such spark plug socket is the Kent-Moore J-39358 spark plug socket. The tool is available from Kent-Moore. For ordering information call 1 -800-345-2233 or write: Kent-Moore SPX Corporation 39784 Little Mack Roseville, MI 48066-2298 Fax: 313-774-9870 Specifications Fluid Line/Hose: Specifications Oil Cooler Fittings to Case 15 ft.lb Oil Cooler Fittings to Radiator 20 ft.lb Page 6770 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. A/T - Fluid Oil Cooler Flush Transmission Cooler: Technical Service Bulletins A/T - Fluid Oil Cooler Flush INFORMATION Bulletin No.: 02-07-30-052G Date: March 02, 2011 Subject: Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow(R) Models: 2011 and Prior Passenger Cars and Light Duty Trucks 2003-2010 HUMMER H2 2006-2010 HUMMER H3 with Automatic Transmission/Transaxle including Allison(R) Transmissions Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 02-07-30-052F (Section 07 - Transmission/Transaxle). Important All labor operations that include removal of the transmission from the vehicle include labor time to flush the transmission oil cooler system. The J 45096 transmission oil cooling system flush and flow test tool replaces current tool J 35944-A. J 45096 is a self-contained unit utilizing a 12-volt flow meter, shop air supply and DEXRON(R) VI automatic transmission fluid (ATF). In the flush mode, transmission fluid is cycled through the transmission oil cooling system. High-pressure air is automatically injected into the fluid stream adding agitation to the ATF oil to enhance the removal of contaminated ATF oil and debris. In the flow mode, an electronic flow meter is used to measure the flow capability of the ATF oil cooling system. A digital display indicates the ATF oil flow rate in gallons per minute (GPM) along with the amount of ATF oil in the supply vessel, supply vessel ATF oil temperature, machine cycles and the operating mode. The supply oil vessel has 30 L (32 qt) capacity and the waste oil vessel has 32 L (34 qt) capacity. The waste oil vessel is constructed of a translucent composite material that allows the user to easily identify the oil level. The waste oil vessel can accommodate vacuum evacuation and gravity draining. In the code mode, a random, encrypted code is generated that can be used for verification of flow test results. Current essential cooler line adapters are used to connect the J 45096 to the automatic transmission oil cooler lines that allows J 45096 to adapt to General Motors passenger cars and light duty trucks, current and past models (except the Pontiac Vibe, Wave and Chevrolet Aveo). The tool may be adapted for use on the Pontiac Vibe, Wave and Chevrolet Aveo by dealership personnel with a barbed hose connector and rubber hose obtained locally. The Vibe's/Wave's/Aveo's transmission has a transmission oil requirement which is slightly different than DEXRON(R) VI ATF. However, flushing the cooler with DEXRON(R) VI automatic transmission fluid is an acceptable service procedure. Very little fluid remains in the cooler after the flush procedure and the residual DEXRON(R) VI ATF in the cooler is compatible with the Vibe's/Wave's/Aveo's transmission fluid. Notice Insufficient oil flow through the ATF oil cooling system will cause premature transmission failure. The required minimum ATF oil flow rate reading is directly related to the supply oil temperature. Refer to the flow rate reference chart for the oil flow rate specification based on the temperature of the ATF in the supply vessel. Helpful Hints for Maintaining the Temperature at or above 18°C (65°F) Important - The temperature of the supply vessel oil must be 18°C (65°F) or greater for J 45096 to operate. It is recommended to store the J 45096 in an area of the dealership where the room temperature remains at or above 18°C (65°F) when not in use. - Do not attempt to increase the fluid temperature in the Transflow(R) machine with an engine oil dipstick, or any other immersion type heater. The Transflow(R) machine has a check valve in the supply reservoir. Inserting a heater will damage the check valve and the subsequent repair expense would be the dealer's responsibility. - A heater blanket, P/N J-45096-10, is available for the Transflow(R) transmission cooling system flushing tool. This heater fastens around the Transflow(R) internal supply vessel and runs on 110 volts AC. The heater will warm the ATF in the supply vessel to at least 18°C (65° F) and has a thermostat to hold a constant temperature. Store the Transmission Cooling System Service Tool, J 45096, Transflow(R) machine in a room where the temperature is maintained at or above 18°C (65°F). Keep the ATF level in the reservoir low when the Transmission Cooling System Service Tool, J 45096, Transflow(R), is not in use. Store several gallons of oil in an area where the temperature is maintained at or above 18°C (65°F). Fill the reservoir of the J 45096 as needed before using the machine on Page 3067 Electronic Control Module (ECM) & Vehicle Speed Sensor Buffer (DRAC) Page 4793 Brake Master Cylinder: Service and Repair Master Cylinder Rebuild Fig. 2 Exploded View Of Master Cylinder DISASSEMBLY 1. Remove master cylinder from vehicle. 2. Remove reservoir cover and diaphragm. Discard old brake fluid in reservoir. 3. Inspect cover and diaphragm. Replace if cut, cracked or deformed. 4. Remove fluid level switch and proportioner valve assembly, if equipped. 5. Depress primary piston and remove lock ring. 6. Plug primary fluid outlet (outlet nearest to cowl when master cylinder is installed), then apply compressed air into secondary fluid outlet to remove primary and secondary pistons. 7. Remove spring retainer and seals from secondary piston. Do not attempt to remove quick take up valve, valve is not serviced separately. 8. Clamp master cylinder in a vise, then remove reservoir using a pry bar. Remove reservoir grommets. 9. Inspect master cylinder bore for corrosion. CAUTION: Do not use abrasive material on master cylinder bore. Replace if bore is corroded. ASSEMBLY Clean all parts not included in repair kit with brake fluid. CAUTION: Do not dry with compressed air. Lubricate all rubber parts with clean brake fluid prior to installation. 1. Lubricate new reservoir grommets with silicone brake lube, then press grommets into master cylinder body. Ensure grommets are properly seated. 2. Lay reservoir upside down on flat, hard surface. Press master cylinder body onto reservoir using rocking motion. 3. Install new seals on secondary piston, then the spring retainer. 4. Install spring and secondary piston assembly into cylinder. 5. Install primary piston. Depress primary piston into cylinder, then install lock ring. 6. Install fluid level switch and proportioner valve assembly, if equipped. 7. Fit diaphragm into reservoir cover, then install cover onto reservoir. 8. Install master cylinder in vehicle. Page 7750 Coolant Level Indicator Lamp: Service and Repair This lamp will be illuminated when engine coolant level in the radiator drops below a pre-determined level. To turn lamp "OFF," check cooling system, then add coolant to bring system to proper level. Wheels/Tires - Use of Nitrogen Gas in Tires Tires: All Technical Service Bulletins Wheels/Tires - Use of Nitrogen Gas in Tires INFORMATION Bulletin No.: 05-03-10-020C Date: April 27, 2010 Subject: Use of Nitrogen Gas in Tires Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-03-10-020B (Section 03 - Suspension). GM's Position on the Use of Nitrogen Gas in Tires General Motors does not oppose the use of purified nitrogen as an inflation gas for tires. We expect the theoretical benefits to be reduced in practical use due to the lack of an existing infrastructure to continuously facilitate inflating tires with nearly pure nitrogen. Even occasional inflation with compressed atmospheric air will negate many of the theoretical benefits. Given those theoretical benefits, practical limitations, and the robust design of GM original equipment TPC tires, the realized benefits to our customer of inflating their tires with purified nitrogen are expected to be minimal. The Promise of Nitrogen: Under Controlled Conditions Recently, nitrogen gas (for use in inflating tires) has become available to the general consumer through some retailers. The use of nitrogen gas to inflate tires is a technology used in automobile racing. The following benefits under controlled conditions are attributed to nitrogen gas and its unique properties: - A reduction in the expected loss of Tire Pressure over time. - A reduction in the variance of Tire Pressures with temperature changes due to reduction of water vapor concentration. - A reduction of long term rubber degradation due to a decrease in oxygen concentrations. Important These are obtainable performance improvements when relatively pure nitrogen gas is used to inflate tires under controlled conditions. The Promise of Nitrogen: Real World Use Nitrogen inflation can provide some benefit by reducing gas migration (pressure loss) at the molecular level through the tire structure. NHTSA (National Highway Traffic Safety Administration) has stated that the inflation pressure loss of tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "seeping" through the tire casing. The actual obtainable benefits of nitrogen vary, based on the physical construction and the materials used in the manufacturing of the tire being inflated. Another potential benefit of nitrogen is the reduced oxidation of tire components. Research has demonstrated that oxygen consumed in the oxidation process of the tire primarily comes from the inflation media. Therefore, it is reasonable to assume that oxidation of tire components can be reduced if the tire is inflated with pure nitrogen. However, only very small amounts of oxygen are required to begin the normal oxidation process. Even slight contamination of the tire inflation gas with compressed atmospheric air during normal inflation pressure maintenance, may negate the benefits of using nitrogen. GM Tire Quality, Technology and Focus of Importance Since 1972, General Motors has designed tires under the TPC (Tire Performance Criteria) specification system, which includes specific requirements that ensure robust tire performance under normal usage. General Motors works with tire suppliers to design and manufacture original equipment tires for GM vehicles. The GM TPC addresses required performance with respect to both inflation pressure retention, and endurance properties for original equipment tires. The inflation pressure retention requirements address availability of oxygen and oxidation concerns, while endurance requirements ensure the mechanical structure of the tire has sufficient strength. This combination has provided our customers with tires that maintain their structural integrity throughout their useful treadlife under normal operating conditions. Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Maintaining the correct inflation pressure allows the tire to perform as intended by the vehicle manufacturer in many areas, including comfort, fuel economy, stopping distance, cornering, traction, treadwear, and noise. Since the load carrying capability of a tire is related to inflation pressure, proper inflation pressure maintenance is necessary for the tire to support the load imposed by the vehicle without excessive structural Page 6685 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 1303 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 2856 Quad Driver: Description and Operation Quad/Output Driver Module The Control Module in this vehicle controls most components with electronic switches which complete a ground circuit when turned on. When the switches are arranged in groups of 4, they can independently control up to 4 outputs and are called Quad Drivers. When the switches are arranged in groups of 7, they can independently control up to 7 outputs and are called Output Drivers. Not all outputs are always used. Shorted solenoid. relay coil. or harness- Solenoids and relays are turned "ON" and "OFF" by the PCM or VCM using internal electronic switches called "drivers." Each driver is part of a group of four called "quad-drivers." Failure of one driver can damage any other driver in the set. A shorted solenoid, relay coil. or harness will not damage the "quad-drivers" in this VCM/PCM, but will cause the circuit and controlled component to be inoperative. When the circuit fault is not present or has been repaired, the "quad-driver" will again operate in a normal manner due to its fault protected design. If a fault has been repaired in a circuit, controlled by a "quad-driver," the original VCM/PCM should be reinstalled and the circuit checked for proper operation. PCM replacement will not be necessary if the repaired circuit or component operates correctly. The J 39200 DVM testers, or equivalent, provide a fast, accurate means of checking for a shorted coil, or a short to battery voltage. The replacement VCM/PCM may be faulty - After the VCM/PCM is replaced, the system should be rechecked for proper operation. If the diagnostic chart again indicates that the VCM/PCM is the problem, substitute a known good VCM/PCM. Page 4089 Transmission Cooler: Technical Service Bulletins A/T - Oil Cooler Flushing Frequently Asked Questions File In Section: 07 - Transmission/Transaxle Bulletin No.: 03-07-30-027 Date: June, 2003 INFORMATION Subject: Most Frequently Asked Questions and Answers for J 45096 TransFlow Transmission Oil Cooling System Flushing Machine Models: 2004 and Prior Passenger Cars and Light Duty Trucks with Automatic Transmission/Transaxle 2004 and Prior HUMMER H2 This bulletin is issued to help answer the most frequently asked questions and concerns about essential tool J 45096. Q: Why doesn't the machine work below 18°C (65°F)? A: The flow characteristics of ATF at temperatures below 18°C (65°F) does not provide accurate flow test results with the electronics used in the J 45096. Q: Why didn't the unit come with a tank heater? A: The vast majority of dealerships do not require a heater to keep the ATF above 18°C (65°F). As a result, the heater was deleted as a cost-savings measure. A tank heater, J 45096-10, is currently available from Kent-Moore if your dealership requires it. Refer to Corporate Bulletin Number 03-07-30-002A for suggestions on warming the ATF without using a heater blanket. Q: Why does the machine fail new oil coolers? A: Several reasons have been found. The most likely reason is the air pressure at the air hose connected to the J 45096 is less than 586 kPa (85 psi). Other reasons include a twisted hose inside the J 45096 at the bulkhead as a result of the nut turning when the waste or supply hose was installed, the internal pressure regulator was improperly set at the factory or a problem with the cooler lines on the vehicle. Perform the J 45096 self-test as described on pages 9 and 10 of the Operation Manual. If a problem is still detected, refer to Troubleshooting on page 19 of the Operation Manual. If a problem still persists, contact Kent-Moore Customer Service at 1-800-345-2233. Q: What is the difference between steel and aluminum oil coolers? A: The aluminum oil cooler tube is slightly thinner in construction than the steel oil cooler tube, which affects the oil flow rate. The fitting that is protruding out of the radiator tank easily identifies the aluminum oil cooler. Refer to the Quick Reference card provided with the J 45096 in order to identify the proper flow rate for the aluminum oil cooler. Q: Why can't I use TransFlow for Allison transmission cooling Systems? A: Validation of TransFlow is currently under development for light duty trucks equipped with the Allison automatic transmission. TransFlow is based on the existing MINIMUM flow rate specification through the transmission oil cooling system. The Allison transmission oil cooling system only has MAXIMUM oil flow rates specified and J 45096 does not have the capability to test the transmission oil cooling system at the maximum oil flow rate specification. Q: Why doesn't GM publish a specification for auxiliary transmission oil coolers? A: The auxiliary oil cooler used with GM vehicles does not contain an internal turbulator plate like the radiator tank oil cooler does. Therefore, there is no internal restriction that would affect the flow rate through the oil cooling system so a specification for auxiliary oil cooler is not required. Keep in mind, kinks and damage to the auxiliary cooler and lines can affect the flow rate through the system. Q: Why did GM drop the labor time for transmission repairs? A: The labor for flushing and flow testing the transmission oil cooling system is included with the R&R; labor of the "K" labor operations that require transmission removal. The time required to use the J 45096 to perform the flush and flow test is much less than that of the J 35944-A. The warranty labor savings allowed GM to provide the J 45096 at no cost to dealerships. Engine - High Oil Pressure Reading at Start-Up Oil Pressure Gauge: All Technical Service Bulletins Engine - High Oil Pressure Reading at Start-Up Number: 93-60-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268306 ASE No.: A1, A8 Subject: HIGH OIL PRESSURE READING AT START-UP Model and Year: 1992-93 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L, AND 5.7L ENGINES Some 1992 and 1993 Chevrolet Light Duty Trucks with oil pressure gauges built after 6/15/92 may exhibit high oil pressure readings at start up, especially when cold. Engines produced after 6/15/92 were built with an enhanced oil pump capable of producing approximately 10 psi more pressure than the previous pump. This may cause the gauge to temporarily read as high as 60 psi during start up. The length of time the oil pressure stays high will depend on oil viscosity, engine temperature, and ambient temperature. This condition will not cause any ill effects on the engine or gauge and unless there are other symptoms to indicate an oil pressure or gauge problem such as very low pressure after warm up, rapid fluctuation, engine noise etc. no repairs should be attempted. Replacing the oil pump or gauge system parts will not be effective. Build date of the engine can be verified by the engine code. The location of this code is illustrated in section OA of the appropriate service manual. The engine code is 8 positions long with an alpha plant designator in the first position, followed in the next four positions by the month and day; for example T0615xxx would indicate that this engine was built in Tonawanda on June 15th and, therefore, has the enhanced oil pump. The plant code is insignificant because all 4.3L, 5.0L, and 5.7L plants began using the enhanced oil pump on the same day. Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 150 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 5124 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Fuel Supply/Return/or Emission Pipes Fuel Supply Line: Service and Repair Fuel Supply/Return/or Emission Pipes NOTES When replacing fuel feed and return pipes, always replace them with original equipment or parts that meet GM specifications for those parts. The replacement pipe must have the same type fittings as the original pipes to ensure the integrity of the connection. Do NOT use copper or aluminum tubing to replace steel tubing. Only tubing meeting the 124M specification or its equivalent is capable of meeting all pressure and vibration characteristics necessary to ensure the durability standard required. Many of the feed and return pipes use screw couplings with O-rings. Any time these fittings are loosened to service or to replace components, ensure that: A back-up wrench is used to loosen and tighten fittings. - Check all O-rings at these locations (if applicable) for cuts or any damage and replace as necessary. - Use correct torque when tightening these fittings. - Inspect all pipes for kinks, leaks or dents. - Pipes must be properly secured to the frame to prevent chafing. A minimum of 6 mm (1/4 inch) clearance must be maintained around a pipe to prevent contact or chafing. - Fuel feed and return pipes are secured to the underbody with clamps and screw assemblies. - Follow the same routing as the original pipe. - Fuel pipes must not contact the fuel tank or underbody at any point. FUEL AND VAPOR PIPE REPAIR When it is impractical to replace an entire fuel line to repair localized damage, use the following procedure: When rubber hose is used to replace pipe, use only reinforced fuel-resistant hose which is identified with the word "Fluoroelastomer" on the hose. The inside diameter of the hose must match the outside pipe diameter. - Do NOT use rubber hose within 100 mm (4 inches) of any part of the exhaust system, or within 254 mm (10 inches) of the catalytic converter. - In repairable areas, cut a piece of hose 100 mm (4 inches) longer than the portion of line removed. If more than a 6 inch length of pipe is removed, use a combination of steel pipe and hose so that hose lengths will not be more than 254 mm (10 inches). - Follow the same routing as the original pipe. - Cut the ends of the pipe, remaining on the car, square with a tubing cutter. Using the first step of a double flaring tool, form a bead on the end of each pipe section. If the pipe is too corroded to withstand the beading operation without damage, the pipe should be replaced. If a new section of pipe is used, form a bead on both ends of it also. - Use a screw type hose clamp NO. #2494772, or equivalent. Slide the clamps onto the pipe and push hoses 51 mm (2 inches) onto each portion of the fuel pipe. Tighten the clamps on each side of the repair. - Pipes must be properly secured to the frame to prevent chafing. Page 6841 Technical Service Bulletin # 461601 Date: 940401 Interior Door Handle Spring - Early Breakage Group Ref.: Body Bulletin No.: 461601 Date: April, 1994 INFORMATION SUBJECT: INTERIOR DOOR HANDLE SPRING BREAKAGE MODELS: 1990-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1990-94 CHEVROLET AND GMC TRUCK S/T UTILITIES 1991-94 OLDSMOBILE BRAVADA Some vehicles may be found to have front side door interior door handles with broken springs. This condition tends to be associated with vehicles that experience high (frequent) usage of the door handle mechanism. To enhance spring durability, production vehicles are now receiving door handle assemblies with lithium grease added to the spring. The durability of replacement door handles obtained from GMSPO can be increased by adding lithium based lubricant to the door handle spring. The lubricant should be applied so that it works into and between the spring coils. This will allow the coils to move past each other freely, reducing spring breakage. SERVICE PARTS INFORMATION: P/N Description Qty Procure Locally Lithium Based As Needed Lubricant Page 1911 Oil Pressure Warning Lamp/Indicator: Testing and Inspection On some models, the oil pressure indicator light also serves as the electric choke defect indicator. If Oil or ENG. indicator light does not light, check to ensure electric choke is not disconnected at carburetor. Also check for defect in electric choke heater, blown gauge fuse or defect in lamp or wiring circuit. If indicator light stays on with engine running possible causes are: low oil pressure, switch to indicator light open circuit, disconnected oil pressure switch connector or oil pressure gauge or radio fuse has blown. The oil pressure warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on, replace the bulb. If the warning light goes on when the wire is grounded, check the engine unit for a poor ground, or improper installation. (The presence of sealing compound on the threads of the engine unit will cause a poor ground.) If the unit is found to be properly grounded and installed, replace the unit. If the warning light remains lit when it normally should be out, replace the engine unit before proceeding to determine the cause for low pressure indication. The warning light will sometimes light or flicker when the engine is idling, even if oil pressure is adequate. However, the light should go out when the engine speed is increased. Locations Horn Switch: Locations Part Of Multi-Function Switch Page 8305 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 3377 Page 3197 Fillpipe Restrictor: Testing and Inspection Fuel Door And Restrictor (Typical) Fuel Filler Neck The fillpipe restrictor should prevent insertion of special dowel with a diameter same as that of leaded fuel pump nozzles (0.950"). Fuel System - 'TOP TIER' Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel System - 'TOP TIER' Detergent Gasoline Information INFORMATION Bulletin No.: 04-06-04-047I Date: August 17, 2009 Subject: TOP TIER Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - U.S. Only Models: 2010 and Prior GM Passenger Cars and Trucks (including Saturn) (U.S. Only) 2003-2010 HUMMER H2 (U.S. Only) 2006-2010 HUMMER H3 (U.S. Only) 2005-2009 Saab 9-7X (U.S. Only) Supercede: This bulletin is being revised to add model years and additional sources to the Top Tier Fuel Retailers list. Please discard Corporate Bulletin Number 04-06-04-047H (Section 06 Engine/Propulsion System). In Canada, refer to Corporate Bulletin Number 05-06-04-022F. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from the use of TOP TIER Detergent Gasoline. Intake valve: - 10,000 miles with TOP TIER Detergent Gasoline Intake valve: - 10,000 miles with Legal Minimum additive Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards As of August 1, 2009, all grades of the following gasoline brands meet the TOP TIER Detergent Gasoline Standards: - Chevron - Chevron-Canada - QuikTrip - Conoco Phillips 66 - 76 Locations Typical Distributor Components Page 2186 RH Front Side Of Engine. RH Side Of Engine Block Applicable to: 1991 4.3L/V6-262 Engine, Bravada Page 8758 used when the customer demands quicker repair of the vehicle than the above described one-part product can provide. This two-part, chemical cure product requires ONE (1) TO ONE-AND-ONE-HALF (1-1/2) HOURS FOR CURING BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This two-part product also requires primers on the glass and pinchweld surfaces. The primers and applicator daubers are not included with this two-part product and therefore, must be purchased separately. In addition, this two-part product requires a special applicator (gun) for proper mixing and dispensing of the adhesive. Important: The U216 product is NOT available from GMSPO and must be obtained locally. * We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. When using either of the above described products, make sure to follow the manufacturer's directions for application and drying times. For information regarding the removal and installation of stationary glass, consult the appropriate Service Manual. Parts information P/N Description 12346392 Urethane Adhesive Caulking Kit Parts are expected to be available from GMSPO, 10/12/98. Important: The previously recommended adhesive kit (P/N 12346284) will no longer be available from GMSPO once inventory is exhausted. Page 5029 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Locations Steering Column Page 7260 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 8355 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 7134 The GM Vehicle Care Odor Eliminator product is an effective odor elimination product when used properly. It must come into direct contact with the odor source. It should be used in conjunction with diagnostic procedures to first eliminate the root cause of the odor. Some procedures for use after odor root cause correction are: STEP TWO: ^ Use the trigger spray head. ^ Put a drop of dish soap the size of a quarter in the bottom of a bottle. ^ Add 8 oz. of GM Vehicle Care Odor Eliminator (1 cup) to the dish soap and top off the bottle with tap water. ^ This formula should be used on hard surfaces (dash, interior plastic molding, and floor pan) STEP THREE: The third step to neutralizing the vehicle is a light to medium treatment of all carpeting and upholstered seats with the GM Vehicle Care Odor Eliminator formula and a wide fan spray setting (at full strength) (i.e.: carpeting on the driver's side requires 4-5 triggers pulls for coverage). The headliner and trunk should be sprayed next. Lightly brushing the formula into the carpeting and upholstery is a recommended step for deep odor problems. The dash and all hard surfaces should be sprayed with dish soap/water mixture. Let stand for 1-2 minutes then wipe off the surface. STEP FOUR: (vehicle ventilation system treatment) The ventilation system is generally the last step in the treatment of the vehicle. a. Spray the GM Vehicle Care Odor Eliminator formula into all dash vents. (1-2 trigger pulls per vent). b. Start the vehicle and turn the vehicle fan on high cool (not A/C setting). c. Spray the formula (10 trigger pulls) into the outside fresh air intake vent (cowl at base of windshield) d. Enter the vehicle after 1 minute and wipe off the excess formula spurting out of the dash vents. e. Smell the air coming from the dash vents. If odors are still present, spray another 5 triggers into the cowl, wait another minute and smell the results. Once you have obtained a fresh, clean smell coming from the vents, turn the system to the A/C re-circulation setting. Roll up the windows, spray 3-5 pumps into the right lower IP area and let the vehicle run with the fan set on high for 5-7 minutes. Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. Additional Suggestions to Increase Customer Satisfaction Here are some additional ideas to benefit your dealership and to generate greater customer enthusiasm for this product. ^ Keep this product on-hand for both the Service Department and the Used Car lot. Add value to your used car trades; treat loaner and demo cars during service and at final sale to eliminate smoke, pet, and other common odors offensive to customers. Make deodorizing a vehicle part of your normal vehicle detailing service. ^ Consider including GM Vehicle Care Odor Eliminator as a give-away item with new vehicle purchases. Many dealers give away as "gifts" various cleaning supplies at time of delivery. GM Odor Eliminator is one of a few products GM offers that has as many uses in the home as in the vehicle. Customers may find this product can be used for a host of recreational activities associated with their new vehicle, such as deodorizing a boat they tow, or a camper. ^ GM Odor Eliminator and many of the GM Vehicle Care products offer you the chance to increase dealership traffic as these superior quality products cannot be purchased in stores. Many Dealerships have product displays at the parts counter. Consider additional displays in the Customer Service Lounge, the Showroom and at the Service Desk or Cashier Window. Many customers who purchase vehicles and receive regular maintenance at your dealership may never visit the parts counter, and subsequently are not exposed to the variety and value that these products offer. Parts Information Page 4397 DISASSEMBLY 1. Remove all bearing cup retainers. 2. Mark bearing cups, spiders, propeller shaft yoke, link yoke and socket yoke for assembly alignment reference, Fig. 9. 3. Remove bearing cups attaching from spider to propeller shaft yoke as follows: a. Use a 5/8 inch socket to drive the bearing cup and a 1-1/16 inch socket to receive the opposite bearing cup as it is driven out. b. Place 5/8 inch socket on one bearing cup and 1-1/16 inch socket on opposite bearing cup. c. Position assembly in vise so vise jaws bear directly against sockets. d. Tighten vise to press first bearing cup out of link yoke. e. Loosen vise, reposition sockets and press opposite bearing cup out of link yoke. 4. Disengage propeller shaft yoke from link yoke. 5. Remove bearing cups attaching front spider to propeller shaft as described in step 3 above. 6. Remove front spider from yoke. 7. Remove bearing cups attaching rear spider to link yoke as outlined in step 3 above and remove spider and socket yoke from link yoke. 8. Clean and inspect assembly for damage or wear. If any component is worn or damaged, the entire assembly must be replaced. ASSEMBLY When assembling universal joint, make sure to align spiders and yokes according to marks made during disassembly. 1. Lubricate all bearings and contact surfaces with lithium base chassis grease. 2. Install bearing cups on yoke ends of rear spider and secure cups with tape, Fig. 9. 3. Assemble socket yoke and rear spider. 4. Position rear spider in link yoke and install bearing cups. Press cups into yoke using 5/8 inch socket until bearing cup retainer grooves are exposed. 5. Install rear spider-to-link yoke bearing cup retainers. 6. Position front spider in propeller shaft yoke and install bearing cups. Press cups into yoke using a 5/8 inch socket until bearing cup retainer grooves are exposed. 7. Install front spider-to-propeller shaft yoke bearing cup retainers. 8. Install thrust washer and socket spring in ball socket bearing bore, if removed. 9. Install thrust washer on ball socket bearing boss (located on propeller shaft yoke), if removed. 10. Align ball socket bearing boss on propeller shaft yoke with ball socket bearing bore and insert boss into bore. 11. Align front spider with link yoke bearing cup bores and install bearing cups. Press cups into yoke using a 5/8 inch socket until bearing cup retainer grooves are exposed. 12. Install front spider-to-link yoke bearing cup retainers. Page 3495 Throttle Cable/Linkage: Service and Repair Accelerator and Cables Repair Procedure Accelerator Pedal Assembly ACCELERATOR PEDAL When performing service on the accelerator pedal, observe the following: The mounting surface between the support and dash panel must be free of insulation. The carpet and padding in the pedal and tunnel area must be positioned to lay flat and be free of wrinkles and bunches. - Slip the accelerator control cable through the slot in the rod and then install the retainer in the rod, makeing sure it is seated. Use care when pressing the retainer into the hole in the rod to ensure that the cable is not kinked or damaged in any way. - After securing all components of the accelerator linkage, the linkage must operate freely without binding between full closed throttle and full wide open throttle. - Wires, hoses, cables or other obstructions must not be placed within 13 mm (1/2 inch) of the cable or the rod at any point in their travel. Accelerator Cable CMFI Page 7446 Brake Vacuum Release Valve: Adjustments With brake or clutch pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Odometer/Speedometer - ACDelco Service Center Locations Odometer: Technical Service Bulletins Odometer/Speedometer - ACDelco Service Center Locations File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-04A Date: September, 1996 INFORMATION Subject: AC Delco Service Center Locations for Odometer/Speedometer Service Models: 1997 and Prior Passenger Cars and Trucks (excluding Cadillac) This bulletin is being revised to provide the necessary contact information only. Please discard Corporate Bulletin Number 66-83-04 (Section 8 - Chassis/Body Electrical) General Motors provides service for sophisticated electronic products through the authorized AC Delco Service Center Program. This program is designed to provide GM vehicle owners with the highest quality and most technically up-to-date product available. Repair products from unauthorized service outlets are not acceptable as warranty replacements. Currently, there are 25 authorized AC Delco Service Centers who exchange and remanufacture odometer/speedometers (list included). Only these Centers should be contacted for service. Important: W series and 1997 T series Medium Duty truck odometer/speedometers must be ordered directly from GMSPO. The following steps should be taken when utilizing the AC Delco Service Centers: Dealers should contact their local AC Delco Service Center (list included). Any listed facility may be used. The following information must be provided: Part number VIN, Mileage, Vehicle Year, Make and Model Dealer Name and Address Delivery Date of Vehicle Name of the person requesting exchange or service Phone number Repair Order Number P.O. number (if non - warranty) Page 1239 ^ Right rear ^ Left rear ^ Right front ^ Left front Note: Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. Note: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 4. Slowly apply the brake pedal one time and hold. 5. Loosen the bleeder valve to purge the air from the wheel cylinder/caliper. 6. Tighten the bleeder valve and slowly release the pedal. 7. Wait 15 seconds. 8. Be sure to check the master cylinder fluid level after 4-5 strokes to avoid running dry. 9. Repeat steps 4 through 8, until all air is purged from the wheel cylinder/caliper. Note: It may be necessary to repeat this sequence as many as 15 to 20 times per wheel. 10. Fill the master cylinder to the proper level and replace lid. 11. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs.in.). 12. Remove the valve pressure bleeding tools J 39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 13. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. Important DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 14. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. Important DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 15. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs. in.). 16. Fill the master cylinder to the proper level with brake fluid. 17. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. Important MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 18. Repeat the entire brake bleed procedure if necessary. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation: H0700 Labor Time: See applicable labor time guide Note: When performing the 4WAL brake system bleeding procedure. the ignition switch must be in the "OFF" position or false diagnostic trouble codes could be set to memory. If trouble codes are set, refer to Section 5E1 "Clearing Diagnostic Trouble Codes" in the 1993 Service Manual. PRESSURE BLEED PROCEDURE Page 6605 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 346 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 5079 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7360 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 6246 Removing/Installing Shaft Seal And O-Ring 6. Shaft seal. - Place J 22974-A over the end of the shaft (38) to prevent cutting the O-ring (13). - Insert J 9392-01 over the compressor shaft (39). - Engage the tabs on the seal (14) by twisting the J 9392-01 to the right. - Engage the tabs and lift the seal (14) out of the shaft (39) cavity hold J 22974-A in place while removing the seal. 7. O-ring (15) with J 9553-01. Install or Connect Tools Required: J 5403 External Snap Ring Pliers J 9392-01 Shaft Seal Remover and Installer J 9393-A Seal Seat Remover and Installer J 9366 Compressor Shaft Nut Socket J 9625-A Pressure Test Set with Schrader Valves J 22974-A Shaft Seal Protector J 23128-A Ceramic Seal Remover and Installer J 33011 O-Ring Installer 1. O-ring (15) with J 33011. - Dip the seal (15) into clean 525 viscosity refrigerant oil. - Insert J 33011 down into the compressor neck until the tool "bottoms." - Lower the movable slide of J 33011 into the lower groove. - Rotate J 33011 to seat the seal (15). - Remove J 33011. 2. Shaft seal. - Coat the seal (14) with clean 525 viscosity refrigerant oil. - Mount the seal (14) to J 9392-01 by engaging the tabs of the seal with the tangs of J 9392-01. - Place J 22974-A over the end of the compressor shaft (39). - Slide the seal (14) and J 22974-A down onto the compressor shaft (38). - Twist J 9392-01 to the right (clockwise) while pushing the seal assembly down the shaft (38) until the seal assembly (14) engages the flats on the shaft and seat in place. - Disengage J 9392-01 by pressing downward and twisting to the left (counterclockwise). 3. Shaft seal seat (13). - Seal (13) to J 23128-A. - Dip the seal (13) into clean 525 viscosity refrigerant oil. Locations Exhaust Layout S/T 2WD PUP 4.3L Body - Marks/Stains on Windshield When Wet Windshield: Customer Interest Body - Marks/Stains on Windshield When Wet TECHNICAL Bulletin No.: 09-08-48-002A Date: March 19, 2009 Subject: Marks/Stains on Windshield When Wet (Clean Windshield) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Supercede: This bulletin is being revised to update the models and model years. Please discard Corporate Bulletin Number 09-08-48-002 (Section 08 - Body and Accessories). Condition Some owners may comment that marks/stains appear on the windshield when the windshield is wet. Cause This condition may be caused by contact between the windshield and the vacuum hoses or other tools used in the assembly process. This contact may leave a residue that creates a water repellent surface on the glass which, in wet conditions, appear as marks/stains on the surface. Correction Important DO NOT REPLACE THE WINDSHIELD FOR THIS CONDITION. To clean the windshield, use Eastwood Glass Polishing Compound*. Follow the manufacturer's directions for product use. Use only hand tools. DO NOT USE POWER TOOLS. Parts Information Eastwood Glass Polishing Compound 1-800-343-9353 (for overseas inquiries: +1-610-705-2200) http://www.eastwoodco.com/ *We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such items which may be available from other sources. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Page 4933 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 7697 Audible Warning Device: Description and Operation Safety Belt Warning Buzzer With the Ignition Switch in START or RUN, voltage is supplied to the Audio Alarm Module (buzzer or chime) through the IGN/GAU Fuse and the PNK/BLK (39) wire, When the Ignition Switch is first turned to START or RUN, voltage from the Audio Alarm Module is supplied to the Fasten Safety Belt Indicator in the instrument cluster through the YEL (237) wire. The indicator stays lit for about five seconds. If the driver's safety belt is not buckled, a ground is applied to the Audio Alarm Module through the WHT (238) wire from the Safety Belt Retractor Switch. The chime or buzzer will sound for about five seconds. Page 7406 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Campaign - 02-313 Stop Delivery Notice Update Fuel Level Sensor: Recalls Campaign - 02-313 Stop Delivery Notice Update ** ADMINISTRATIVE MESSAGE 01-277 CREATED ON 9/5/91 AT PAGE 1 OF 1 TO: ALL CHEVROLET DEALERS SUBJECT: STOP DELIVERY NOTICE 1992 S/T TRUCKS THIS IS WITH FURTHER REFERENCE TO THE 1992 S/T TRUCK STOP DELIVERY DCS ADMIN MESSAGE 01-258 DATED 8/22/91 SENT TO ALL CHEVROLET DEALERS. SELECT DEALERS WERE ADVISED IN DCS MESSAGE 02-313 DATED 9/5/91 OF PRODUCT CAMPAIGN 92C02 FUEL LEVER SENDER ARM/TANK INTERFERENCE. THIS DCS INCLUDED INVOLVED DEALER CODES AND INVOLVED VIN'S. ANY DEALER NOT RECEIVING DCS ADMIN MESSAGE 02-313 HAS NO INVOLVED VEHICLES ASSIGNED AND VIN'S WHICH FALL WITHIN THE ORIGINAL VIN RANGES LISTED BELOW ARE RELEASED FROM THE STOP DELIVERY. ASSEMBLY PLANT STARTING VIN ENDING VIN PONTIAC WEST N0100014 N0101228 MORAINE N2100052 N2101700 SHREVEPORT N8100014 N8101560 PLEASE COMMUNICATE THIS INFORMATION TO ALL DEALERSHIP MANAGEMENT IMMEDIATELY UPON RECEIPT. Page 3236 Fuels Oxygenated fuels, with methanol and/or ethanol blended into the gasoline have lower energy and thus reduce fuel economy. Typically there is about a 1 MPG penalty for a vehicle which gets 25 to 30 MPG on 100 percent gasoline. Using fuels of a lower octane than the vehicle was calibrated to will cause increased "KS" Knock Sensor system activity. This will result in a net decrease in spark advance and thus poorer fuel economy. Using fuel of a higher octane than the vehicle was calibrated for WILL NOT increase fuel economy. Variations in how much fuel is added to the fuel tank during re-fueling can greatly affect calculated fuel economy. These effects decrease as the distance traveled and the number of tank fillups increase. Green Engine New vehicles have not yet had an opportunity for the engine to break in, (rings to seat ... ). A typical engine will take 3 to 5 thousand miles to break in and during this time period a gradual increase in fuel economy can be expected. Parasitic Loads Air conditioning and/or electrical loads, (headlights, heated backglass ... ) also result in lower fuel economy, (typically less than 1 MPG difference, each 10 AMPs takes approximately .4 MPG). Road Conditions Road surface condition impacts fuel economy. Gravel and/or pot holed roads decrease fuel economy. Hills (vs. level terrain) also negatively impact fuel economy. Even gradual unperceptible increases in elevation result in real measurable decreases in fuel economy. Similarly, driving in the rain or snow decreases fuel economy. Suspension Vehicle suspension misalignment can cause poor fuel economy. Check all four tires for abnormal and/or premature tire wear. New tires, tire rotation, and/or front end alignment may be required to correct fuel economy. Tires Performance tires and/or tires with larger "contact areas," (like 60 series aspect ratio), can cause as much as 3 MPG lower fuel economy when compared to hard "thin" tires. Find out if the tire size currently on the car is the same as original equipment. Replacement tires tailor than original equipment tires cause the odometer to read LESS THAN actual distance traveled. This will result in lower calculated fuel economy than actual fuel economy. Tire Pressure Harder tires, (more air pressure, or different tire compositions) result in better fuel economy. Do not exceed maximum pressure as labeled on the tire, typically 30-35 psi. The disadvantage of this is that the greater the tire pressure, the harsher the vehicle ride. Transmission On 4-Speed automatics, it is possible to drive the vehicle in 3rd gear rather than "overdrive" and not perceive it. Typically this condition occurs when the shift indicator, or the shift linkage/detent is misadjusted. Misadjusted shift linkage can also result in improper signals to the ECM, which can result in less spark advance, and results in a drop in fuel economy. Driving a vehicle in 3rd gear rather than overdrive at highway speeds typically results in a 3 to 5 MPG penalty. Torque Converter Clutch operation is essential for good fuel economy. A non-locking torque converter typically results in a 1 to 2 MPG penalty at highway speeds. Vehicle Weight Each 125 lbs. of additional weight results in a .3 MPG loss of fuel economy. Thus, additional passengers, luggage ... will decrease fuel economy. Vehicle Wind Resistance More wind "DRAG" means less fuel economy. Thus, hang-on luggage carders, cat toppers, open windows and/or open trunk... mean less fuel economy. (See "Driving Habits"). Page 1019 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 8570 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 8424 Parking Lamp: Description and Operation Rear Voltage is supplied through the CRANK Fuse to the Light Switch at all times. With Light Switch in PARK or HEAD, voltage is supplied to the Tail, Marker, Endgate, Clearance and License Lamps. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 5657 Steering Gear: Adjustments Saginaw Integral Power Steering Gear Worm Bearing Preload Fig. 12 Adjuster plug nut removal Fig. 4 Adjuster plug removal Fig. 13 Adjuster plug alignment mark Page 3108 EGR Valve: Technical Service Bulletins MIL ON - DTC 32/EGR Valve Failure Group Ref.: Engine Fuel & Emission Bulletin No.: 376513 Date: November, 1993 SUBJECT: DIAGNOSTIC TROUBLE CODE 32 (REPLACE LEGR VALVE AND BASE GASKET, REPAIR COWL BURN THROUGH) MODELS: 1992-93 CHEVROLET AND GMC M/L VANS AND SIT TRUCKS 1992-93 OLDSMOBILE BRAVADA (EQUIPPED WITH 4.3L (L35) ENGINE) CONDITION: Some owners may experience Diagnostic Trouble Code (DTC) 32 and Linear Exhaust Gas Recirculation (LEGR) valve failure. The vehicle may have a rough idle or lack of power (valve failed open), or detonation (valve failed closed). CAUSE: Water intrusion into the LEGR valve coil housing. The valve corrodes internally, causing the pintle to stick. A stuck pintle will cause a DTC 32 to be set because the actual LEGR pintle position will not be within 20 percent of the desired LEGR pintle position. CORRECTION: M/L Van Replace the failed LEGR valve with P/N 17093134 and LEGR base gasket 3522442. For M/L vans built before February 1993, inspect the cowl area for spot weld burn-through (see illustration). If burn-through is found, repair with body putty. S/T Trucks Replace the failed LEGR valve with P/N 17093134 and LEGR base gasket 3522442. The latest LEGR valve has an RTV seal added to the cap and housing crimp area to prevent water intrusion into the valve coil housing. PARTS INFORMATION: Linear Exhaust Gas 17093134 Recirculation Valve Page 4659 Caliper Knuckle Clearances 8. Measure the clearance between the caliper and the steering knuckle. The clearance at each end of the caliper should be measured individually and added together. this total should be between 0.26-0.60 mm (0.010-0.024 inch). 9. Install tire and wheel assembly. 10. Lower the vehicle. WARNING: Before moving vehicle, pump brake pedal several times to be sure it is firm. Do not move vehicle until a firm pedal is obtained. Page 38 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Diagram Information and Instructions Cruise Control Vacuum Vent Solenoid: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 3134 Fillpipe Restrictor: Testing and Inspection Fuel Door And Restrictor (Typical) Fuel Filler Neck The fillpipe restrictor should prevent insertion of special dowel with a diameter same as that of leaded fuel pump nozzles (0.950"). Page 52 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 5732 5. Reposition the vertical tangs (85) in the upper spring pocket bracket (86) by bending them inward with pillars in a horizontal position (Figure 8). Remove any sharp edges or burrs off of the upper coil spring pocket by using a die grinder or metal file. CAUTION: The upper spring pocket has sharp edges and burrs on it. Care must be taken to avoid personal injuries. Install or Connect (Figures 1, 2, 3, 4, 5, 6, 7, and 8): Tool Required: J23028-01 Coil Spring Remover and Installer. 1. Install Service Kit (P/N 15989719) one insulator with insert on the top of coil spring and remaining insulator on the bottom of the coil spring (If the opposite side of the vehicle requires the same repair procedures, then another Service Kit (P/N 15989719) will be required.) 2. Install the coil spring (37) with insulators (73) on the lower control arm (40) (Figure 1). a. Using J23028-O1 to support the control arm (Figure 5). b. Position the coil spring (A) (Figure 6). - Coil spring installed with the tape at the lowest position and a gripper notch at the top. - Inspect drain holes, one of which must be covered by the end of the spring and one must be open. 3. Install the lower control arm (40) to the frame. 4. Install the pivot bolts (72 and 77) and nuts (71 and 78) (Figure 1). IMPORTANT: In order to maintain adequate steering linkage clearance, refer to mandatory bolt direction of installation in Figure 6. - Mandatory Bolt and Nut Positions - Front Bolt First Tighten: a. Tighten front nut (76) to 90 N-m (67 lbs.ft.) (Figure 1). b. Tighten rear nut (71) to 90 N-m (67 lbs.ft.) (Figure 1). 5. Install stabilizer shaft (53) to lower control arm (40). a. Install the retainer (61), and grommet (60) (Figure 3) to the link bolt (62) (Figure 3). Page 6743 Symbol Identification Page 3427 Fuel Level Sending Unit: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVE/DISCONNECT - Negative battery cable. - Raise vehicle. - Fuel tank. - Pump and sending unit assembly by turning cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. Pull fuel pump up into attaching hose while pulling outward from the bottom support. Do not damage rubber insulator or strainer. INSPECT - Inspect fuel pump attaching hose for signs of deterioration. - Inspect rubber sound insulation at bottom of pump for deterioration. INSTALL/CONNECT - Pump assembly into attaching hose. NOTE Care should be taken not to fold over or twist strainer when installing sending unit as this will restrict fuel flow. - Sending unit and fuel pump assembly into fuel tank. (Always use a new O-ring seal). - Cam lock assembly. Turn cam lock clockwise to lock it. - Fuel tank assembly. - Negative battery cable. - START vehicle and check for fuel leaks. - Lower vehicle. Page 7749 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Page 4386 Fig. 14 Using Spacer To Completely Drive Out Bearing Cup Fig. 15 Solid Ball & Replaceable Balls. Notch Identifies Driveshaft With Replaceable Ball Fig. 16 Exploded View Of Ball & Seat DISASSEMBLY Constant Velocity Joint To disassemble the constant velocity joint, the bearing cups should be removed in sequence shown in Fig. 11. This method requires the least amount of work. 1. Mark all yokes before disassembly as shown in Fig. 12, so that they can be reassembled in their original relationship to maintain driveshaft balance. The following procedure can be performed in a vise. A cross press tool, Fig. 13, can be used in place of the socket used to drive the bearing cups. 2. Support the driveshaft horizontally in line with the base plate of a press. Place rear end of coupling yoke over a 1-1/8 inch socket to accept the bearing cup. Place a socket slightly smaller than the bearing cup, on the opposite side of the spider. 3. Press bearing cup out of coupling yoke ear. If bearing cup is not completely removed, insert spacer C-4365-4 or equivalent, Fig. 14, and complete removal of bearing cup. 4. Rotate driveshaft 180° and shear the opposite retaining ring, and press the bearing cup out of the coupling yoke as described previously, using spacer C-4365-4 or equivalent. Page 3432 Idle Speed/Throttle Actuator - Electronic: Description and Operation Idle Air Control (IAC) System IAC Valve IAC System PURPOSE To control engine idle speed and prevent stalling due to changes in engine load. OPERATION All engine idle speeds are controlled by the control module through the Idle Air Control (IAC) valve mounted on the throttle body. The control module sends voltage pulses to the IAC motor windings causing the IAC motor shaft and pintle to move "IN" or "OUT" a given distance (number of steps) for each pulse (called counts). Inward movement of the pintle = Decreased RPM =Lower Counts. Outward movement of the pintle = Increased RPM = Higher Counts. This movement controls airflow around the throttle plate, which in turn, controls engine idle speed, either cold or hot. IAC valve pintle position counts can be seen using a Tech 1 scan tool. Zero (0) counts correspond to a fully closed passage, while 140 counts or more (depending on the application) corresponds to full flow. - Actual or "controlled" idle speed is obtained by the control module positioning the IAC valve pintle. Resulting idle speed is generated from the total Page 6342 INSPECT - Be sure the installed hose(s) do not sag or rub against other components. Adjust or support the hose as necessary to correct. - Operate the engine and check the hose installation for leaks. - Tighten the hose clamp screw a bit at a time, if necessary, to stop a leak. - Check the coolant level after the engine has been warmed up and allowed to cool. Add coolant as required. Page 2987 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Specifications Idle Speed: Specifications CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Auto D 550 5-40 CL [1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). Page 2329 Temperature Gage Indicates Cold All The Time Page 324 Brake Vacuum Release Valve: Adjustments With brake or clutch pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. HP Engine Exhaust Pressure Regulator Vacuum Valve: Locations HP Engine Engine Compartment Components Front Of Engine Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 HP Engine Page 7372 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 2162 coolant system integrity and will no longer be considered a 5 yr/150,000 mile (240,000 km) coolant. Coolant Removal Services/Recycling The tables include all coolant recycling processes currently approved by GM. Also included is a primary phone number and demographic information. Used DEX-COOL(R) can be combined with used conventional coolant (green) for recycling. Depending on the recycling service and/or equipment, it is then designated as a conventional 2 yr/30,000 mile (50,000 km) coolant or DEX-COOL(R) 5 yr/150,000 mile (240,000 km) coolant. Recycled coolants as designated in this bulletin may be used during the vehicle(s) warranty period. DEX-COOL(R) Recycling The DEX-COOL(R) recycling service listed in Table 2 has been approved for recycling waste engine coolants (DEX-COOL) or conventional) to DEX-COOL(R) with 5 yr/150,000 mile (240,000 km) usability. Recycling Fluid Technologies is the only licensed provider of Recycled DEX-COOL(R) meeting GM6277M specifications and utilizes GM approved inhibitor packages. This is currently a limited program being monitored by GM Service Operations which will be expanded as demand increases. Conventional (Green) Recycling Page 770 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 4599 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 1179 contact or return to the previous repair facility. Explain that environmental regulations prohibit repair facilities from discharging ozone depleting A/C refrigerants into the atmosphere. Explain that recovery of this unknown refrigerant could damage your service equipment. If the customer wishes to pursue repairs through your facility, it is recommended that the proper A/C service equipment be purchased. General Motors recommends the Kent-Moore J 41428 "Scavenger", an air operated refrigerant recovery station, be used to remove unknown refrigerants. The air operated feature reduces the hazard of recovering potentially flammable refrigerants. Dealers should evaluate the need to purchase the equipment based on the number of contaminated vehicles they encounter. As an alternative to the initial purchase of a recovery only station, dealers should check locally for A/C specialty shops which may have the equipment to service substitute or contaminated refrigerants. They may be able to provide contaminated refrigerant recovery service to the dealer. The GM Service Technology Group has tested a recovery procedure where a 15 or 30 pound DOT approved refillable tank is fully evacuated then connected to a vehicle A/C system to recover the charge. Testing has shown that even when the recovery tank is cooled down in dry ice, the procedure does not guarantee the entire charge will be recovered. Since EPA regulations require full recovery of ozone depleting substances, GM does not recommend this procedure. Contaminated Refrigerant Disposal Although A/C refrigerant testing and disposal have not been a service practice in the mobile A/C industry, It has been common in the stationary A/C service industry for many years. Listed at the end of this bulletin are companies that provide refrigerant disposal service for the stationary A/C industry. Please be advised that GM has not independently evaluated these companies and is not in any way endorsing or promoting the use of these companies. Each of these companies has expressed an interest in providing refrigerant disposal service to GM dealers. In working with the stationary A/C industry, these companies typically receive large volumes of different refrigerants that have been mixed together. Unfortunately, because the volume of material returned by the mobile A/C industry will be in much smaller quantities, the cost of handling will be greater. To arrange for return of the refrigerant, simply call the company nearest you using the phone number listed below. The company will advise you on billing and shipping procedures. Disposal cost will vary between $3.00 and $5.00 per pound plus freight and handling. Shipping charges will vary by distance and location. In general, a 7 to 10 day turn-around time on the tank can be expected. The tank can be shipped via common carrier. Documents that your refrigerant has been properly disposed of will be sent to you with the return of your tank. As an alternative, many dealerships already have contracts in place with a disposal company who manages their hazardous wastes. In these cases, the disposal service may agree to handle containers of mixed refrigerants. Initially, the local disposal companies may be surprised by this inquiry. They may want to evaluate how much material will be collected before deciding whether to provide this service. As we move forward with the practice of testing R12 refrigerant, it will take time for all the questions to be answered. STG will provide additional information as soon as it is available. Understanding The PureGuard The PureGuard is a highly sensitive instrument capable of detecting R12 with 3% or less cross-contamination with other refrigerants. Any refrigerant mixture in excess of this amount poses a threat to both your refrigerant supply and recovery equipment. The PureGuard uses a pass/fail approach when monitoring the refrigerant and is precisely calibrated to cut power to the recovery machine if it encounters R12 mixed with any substitute refrigerants. The PureGuard ignores the presence of the air, dyes or oils in the refrigerant sampled. At least 20 psi must be present in the vehicle's A/C system for the PureGuard to function. Otherwise, refrigerant cannot be introduced to the PureGuard's test chamber. If a vehicle's A/C system contains less than 20 psi, it is an indication that the vehicle's system is nearly depleted of refrigerant. Occasionally, erratic PureGuard operation or service code 002 display will be encountered when A/C system pressure is exactly 20 psi. If this occurs, simply cycle the on/off switch to reset the PureGuard. After the 30 second PureGuard warm-up cycle, proceed immediately with vehicle recovery operation. Feedback from the field has indicated PureGuard service code 002 will also be displayed if the oil drain port is not sealed. Make sure the "0" ring seal in the cap is in place and that the cap is tight. If the PureGuard fails to clear or if you experience any other problems operating the PureGuard, contact Kent-Moore Technical Service at 1-800-345-2233. The unit should not be returned without first contacting Kent-Moore to obtain return authorization. Refrigerant Disposal Locations: United States Refrigerant Reclamation Inc. 12420 North Green River Rd. Evansville, IN 47711 800-207-5931, FAX - 812-867-1463 Page 2590 Chart 6 Vehicle Speed Sensor Test Page 7202 Symbol Identification Page 344 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Page 5206 For vehicles repaired under warranty, use the table. Disclaimer Page 4090 Q: Why didn't the machine come with the adapters to hook up to the car? A: The J 45096 was designed to use the previously released essential cooler line adapters for the J 35944-A. All adapters are listed on page 17 of the Operation Manual and can be ordered from Kent-Moore at 1-800-345-2233. Q: How do I connect the J 45096 to a Catera, Prizm or a Vibe? A: These vehicles, along with many other models, only require barbed fittings to connect to the rubber cooler hose. These fittings are commercially available and already found in many shops. Q: Why didn't I receive an Operation Manual with the machine? A: The Operation Manual was packaged in the upper portion of the shipping carton. If the shipping carton was lifted off the base without opening the top of the carton, the Operation Manual could have been discarded with the carton. Replacement Operation Manual packages can be obtained from Kent-Moore Customer Service at 1-800-345-2233. Q: Why can't I re-use the transmission fluid I use for flushing? A: The very fine metal and clutch material debris from the transmission failure in the ATF causes failures with the hall effect speed sensors that are used to measure the flow rate. To avoid costly repairs, expensive filters, regular maintenance and problems caused by a partially restricted filter, the filter was not included. Q: What do I do if I need service on my machine? A: Call Kent-Moore Customer Service at 1-800-345-2233. The J 45096 has a one-year warranty. Q: Can I flush and flow engine oil coolers? A: The engine oil cooler flow rates, the appropriate adapters and an acceptable procedure are currently under development. Disclaimer Page 1078 Coolant: Specifications Less A/C 12.1 qt (US) With A/C 12.1 qt (US) Locations Engine Wiring, LH Side Page 3173 Accelerator Controls: Service and Repair Accelerator Pedal Assembly ACCELERATOR PEDAL When performing service on the accelerator pedal, observe the following: The mounting surface between the support and dash panel must be free of insulation. The carpet and padding in the pedal and tunnel area must be positioned to lay flat and be free of wrinkles and bunches. - Slip the accelerator control cable through the slot in the rod and then install the retainer in the rod, makeing sure it is seated. Use care when pressing the retainer into the hole in the rod to ensure that the cable is not kinked or damaged in any way. - After securing all components of the accelerator linkage, the linkage must operate freely without binding between full closed throttle and full wide open throttle. - Wires, hoses, cables or other obstructions must not be placed within 13 mm (1/2 inch) of the cable or the rod at any point in their travel. Accelerator Cable CMFI ACCELERATOR CONTROL CABLE Lighting - Exterior Lamp Condensation and Replacement Parking Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Page 4675 Brake Rotor/Disc: Fundamentals and Basics Wheel Bearing Inspection and Repacking WHEEL BEARING INSPECTION Inspect the wheel bearing closely for the following: Fatigue Spalding Look for small flakes of shiny metal (babbit) embedded in the grease. This can easily be done by dragging the bearing across a clean shop towel. Any metal flakes will be readily visible in the grease deposited on the shop towel. If any flakes are found the wheel bearing should be replaced. Brinelling Look for a series of vertical indentations on the races. This is caused by impact loading or vibration while the bearing is not rotating. Replace the bearing if the indentations are severe or the bearing is noisy. Heat Discoloration Heat discoloration can range from faint yellow to dark blue. This results from the bearing being adjusted too tightly or an insufficient amount of lubricant/grease. Excessive heat can cause the races and rollers to soften. To check for a loss of temper on the races or rollers a simple file test may be performed. A file drawn lightly over a race or roller which has lost its case hardening will grab and cut metal, whereas a file drawn lightly over a hardened part will glide readily without scratching the metal. Replace the bearing and race if softening is indicated. Cracked Outer Race Cracked races often result from the race being driven in cocked or at an angle. Replace the bearing and race and be careful to drive the new race in evenly. Loose Outer Race Check to see that the race is tight and secure in the hub. If there is any evidence of movement or slippage, replace both the hub assembly and the bearing. Bent or Damaged Cage Verify that the cage has not been bent or distorted. Bent or damaged cages are often the result of improper bearing and grease seal removal techniques. When removing the inner wheel bearing use a seal puller to remove the grease seal. The inner bearing should then just slide out of the hub. Page 4088 Disclaimer Page 5382 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 5172 Figure 7 Figure 8 Figure 9 Figure 10 Page 6055 Air Door Actuator / Motor: Locations Outside Air Door Actuator Heater & A/C Components, Instrument Panel Under Air Inlet On RH Side Of Dash Panel Page 6234 Compressor Clutch Hub: Service and Repair With HR6-HE Compressor Remove or Disconnect Clutch Plate And Hub Assembly Removal 1. Clamp the holding fixture J 33026 in a vise and attach compressor to holding fixture with thumb screws J 33026-1. 2. With center screw forcing tip in place to thrust against the end of the shaft, thread the Clutch Plate and Hub Assembly Installer-Remover J 33013-B into the hub. Hold the body of the remover with a wrench and turn the center screw into the remover body to remove the clutch plate and hub assembly. NOTICE: Do not drive or pound on the clutch hub or shaft. Internal damage to compressor may result. The forcing tip on J 33013-B remover-installer center screw must be flat or the end of the shaft/axial plate assembly will be damaged. 3. Remove the shaft key and retain for reassembly. Install or Connect Page 8405 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 1839 - Apply sealant (GM part number 1052080 or equivalent) to the front cover to block joint and to the crankshaft rear seal retainer to block joint. Apply the sealant for about 25 mm (1 inch) In both directions from each of the four corners. 1. Oil pan gasket to the oil pan. 2. Oil pan to the engine. 3. Oil pan bolts, nuts, and reinforcements. Tighten - Oil pan bolts to 11 N.m (100 in. lbs.). - Oil pan nuts at corners to 23 N.m (17 ft. lbs.). 4. Engine to the vehicle. 5. Proper quantity and grade of engine oil. Page 6013 sure the retainer cup is tree from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. Important: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Except for the N9O 4X4 wheel used on T trucks, all light truck aluminum wheels will accept either "AW" series or "MO" series clip-on coated weights on both the inside and outside rim flanges. The N9O T truck wheel will accept "AW" series weights on the inside rim flange only. The outside rim flange is not designed to accept a clip-on weight. If such a weight installation is attempted, a poor fit will result, and the weight may fall off and/or cause cosmetic damage to the rim flange. This wheel can be 1) static balanced by clipping all the weight on the inside rim flange (as is done in the assembly plant), or 2) dynamic balanced by clipping a weight on the inside flange and using an adhesive weight near the outside flange. The charts show "AW" and "MC" balance weight usage. These original equipment coated weights are available at competitive prices through the GM Dealer Equipment program. Page 7511 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 6974 Dashboard / Instrument Panel: Service and Repair Fig. 23 Lamp Switch Removal & Installation Fig. 24 Instrument Panel Components Page 335 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 4642 Brake Caliper: Testing and Inspection Should it become necessary to remove the caliper for installation of new parts, clean all parts in denatured alcohol or brake parts cleaner, wipe dry using lint-free cloths. Using compressed air, blow out drilled passages and bores. Check dust boots for punctures or tears. If punctures or tears are evident, new boots should be installed upon reassembly. Inspect piston bores in both housings for scoring or pitting. Bores that show light scratches or corrosion can usually be cleaned with crocus cloth. However, bores that have deep scratches or scoring may be honed, provided the diameter of the bore is not increased more than 0.05 mm (0.002 inch). If the bore does not clean up within this specification, a new caliper housing should be installed (black stains on the bore walls are caused by piston seals and will do no harm). When using a hone, be sure to install the hone baffle before honing bore. The baffle is used to protect the hone stones from damage. Use extreme care in cleaning the caliper after honing. Remove all dust and grit by flushing the caliper with denatured alcohol or brake parts cleaner. Wipe dry with clean lint-free cloth and then clean a second time in the same manner. Page 49 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 435 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 5546 Important When performing adjustments to vehicles requiring a 4-wheel alignment, set the rear wheel alignment angles first in order to obtain proper front wheel alignment angles. Perform the following steps in order to measure the front and rear alignment angles: 1. Install the alignment equipment according to the manufacturer's instructions. 2. Jounce the front and the rear bumpers 3 times prior to checking the wheel alignment. 3. Measure the alignment angles and record the readings. If necessary, adjust the wheel alignment to vehicle specification and record the before and after measurements. Refer to Wheel Alignment Specifications in SI. Important Technicians must refer to SI for the correct wheel alignment specifications. SI is the only source of GM wheel alignment specifications that is kept up-to-date throughout the year. Test drive vehicle to ensure proper repair. Page 1071 coolant system integrity and will no longer be considered a 5 yr/150,000 mile (240,000 km) coolant. Coolant Removal Services/Recycling The tables include all coolant recycling processes currently approved by GM. Also included is a primary phone number and demographic information. Used DEX-COOL(R) can be combined with used conventional coolant (green) for recycling. Depending on the recycling service and/or equipment, it is then designated as a conventional 2 yr/30,000 mile (50,000 km) coolant or DEX-COOL(R) 5 yr/150,000 mile (240,000 km) coolant. Recycled coolants as designated in this bulletin may be used during the vehicle(s) warranty period. DEX-COOL(R) Recycling The DEX-COOL(R) recycling service listed in Table 2 has been approved for recycling waste engine coolants (DEX-COOL) or conventional) to DEX-COOL(R) with 5 yr/150,000 mile (240,000 km) usability. Recycling Fluid Technologies is the only licensed provider of Recycled DEX-COOL(R) meeting GM6277M specifications and utilizes GM approved inhibitor packages. This is currently a limited program being monitored by GM Service Operations which will be expanded as demand increases. Conventional (Green) Recycling ABS - Brake Bleeding Procedure Technical Service Bulletin # 931985 Date: 930501 ABS - Brake Bleeding Procedure Number: 93-198-5 Section: 5 Date: MAY 1993 Corporate Bulletin No.: 365003 ASE No.: A5 Subject: REVISED 4WAL BRAKE SYSTEM BLEEDING PROCEDURE Model and Year: 1990-93 M/L, S/T 1992-93 C/K 1993 G MODELS WITH 4WAL SERVICE UPDATE Bulletin Description THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-74-5 DATED OCTOBER 1990 TO UPDATE THE BLEED PROCEDURE AND TO ADD MODELS SINCE EQUIPPED WITH 4WAL BRAKE SYSTEMS. ALL COPIES OF 91-74-5 SHOULD BE DISCARDED. THIS BULLETIN ALSO UPDATES INFORMATION IN 1993 M/L SERVICE MANUAL, 1993 S/T SERVICE MANUAL, 1993 C/K SERVICE MANUAL, 1993 G SERVICE MANUAL, AND STG RWAL/4WAL 1988-1991 APPLICATIONS MANUAL 15005.05 (VERSIONS 2 TO 5). PLEASE PLACE A COPY OF THIS BULLETIN IN EACH MANUAL. THIS BULLETIN IS EQUIVALENT TO SERVICE MANUAL UPDATE BULLETIN 93-12-5, DATED SEPT. 1992. This 4WAL brake system bleed procedure is the most efficient bleed procedure to date. The 4WAL Brake Pressure Modulator Valve (BPMV), formerly called Electro Hydraulic Control Unit (EHCU), should be bled after replacement or if air is suspected to be trapped inside the unit. There are two conventional methods to use when bleeding the 4WAL BPMV: (1.) Pressure Bleeding or (2.) Manual Bleeding. IMPORTANT: There are two internal bleed screws (brass colored), one on each side of the BPMV, that open internal channels. Open the internal bleed screws 1/4 to 1/2 turn before bleeding (figure 2). New 4WAL BPMV's are shipped with the internal bleed screws open, so first close the internal bleed screws until snug, then open 1/4 to 1/2 turn. NOTICE: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Clean any fluid that may drip onto wheel cylinders or calipers to prevent corrosion. Always re-seal and wipe off brake fluid containers to prevent spills. Tools Required Page 1776 Labor Operation Labor Time T7460 0.2 hours Clean A/C pulley and inspect for proper alignment 0.2 hours Loosen and align P/S pump pulley (include R and R lower shroud) Note: T7460 is coded to base vehicle coverage in the warranty system. For vehicles repaired under warranty for replacing serpentine belt use: Labor Operation Description Labor Time J0667 Belt-Drive, Replace See Applicable Labor Time Guide Page 4974 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 302 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 3763 PROM - Programmable Read Only Memory: Service and Repair EPROM REMOVAL: ^ DO NOT remove an EPROM from its packing material until you are ready to install it. DO NOT hold an EPROM by its pins. ^ Before entering a vehicle to remove or replace an EPROM, touch an exposed metal part of the vehicle to discharge any static charge from your body or use anti-static wrist straps. Avoid sliding across upholstery or carpeting when removing or installing an EPROM. If this is not possible, touch an exposed metal part of the vehicle with your free hand before removing or replacing an EPROM. ^ When available, use an antistatic grounding strap attached to your wrist and clipped to a metal part of the vehicle body to prevent static charges from accumulating. Antistatic conductive floormats are also available. ^ It may be desirable to remove the computer for EPROM replacement. ^ Remove computer access cover. ^ Unlock the locking levers by pressing outward toward the sides of the EPROM. ^ Remove EPROM from its socket INSTALLATION: EPROM/MEM-CAL Unit Installation ^ Install the replacement EPROM in the same direction. ^ VERY GENTLY PRESS down on the ends of the EPROM until the locking levers are rotated toward the sides of the EPROM. ^ NOTE: To avoid Computer damage, do not press on the ends of the EPROM until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the EPROM into its socket. ^ While continuing light pressure on the ends of the EPROM, use your index fingers to press the locking levers inward until they are snapped into place. Listen for the click. ^ Install the access cover on the computer. ^ Perform FUNCTIONAL CHECK Page 7270 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 7109 Wiper arms Cowl vent grille Grille and headlamp bezels Front bumper filler panel Antenna Side view mirrors Side marker lamps Tail lamps Door edge guards Wheel opening moldings *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary Swing out windows/seals WARRANTY INFORMATION For vehicles repaired under warranty. and for customer satisfaction. use: Labor Op (Labor Operations include mix time) A6100 Refinish the entire exterior body surface ABOVE THE BODY SIDE MOLDING AND INSERT COLOR on two tone vehicles if equipped. A6101 Refinish the entire exterior body surface INSERT COLOR only. A61O2 Refinish the PICKUP BOX LOAD FLOOR AND INNER FENDERS when applicable. A61O3 On units with an insert color, included is the entire exterior body surface ABOVE THE BREAKLINE. (If the insert color and the entire body surface above the break-line requires refinishing, use A6100). Page 6548 Important: Before using the tester and the diagnostic chart, the following two steps must be performed. 1. Verify that the keyless entry transmitter is the correct model for the vehicle remote system. An incorrect model transmitter may pass this test, but may not activate the vehicle remote system. The correct transmitter can usually be identified by part number. 2. Ensure that the transmitter is synchronized with the vehicle (if applicable). Refer to Transmitter Synchronization in the appropriate Service Manual. Page 7557 Figure 7 Figure 8 Figure 9 Figure 10 Page 5475 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 1207 Page 156 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Extended Cab Rear Lamps Wiring Harness Description and Operation Fuel Pump Relay: Description and Operation OPERATION When the ignition key is first turned to the "ON" position, the control module will energize the fuel pump relay as long as the engine is cranking or running, and the control module is receiving distributor reference pulses. If there are no reference pulses, the control module will shut "OFF" the fuel pump relay within two seconds. An inoperative fuel pump relay can result in extended crank times, particularily if the engine is cold. The oil pressure switch will turn "ON" the fuel pump, as soon as oil pressure reaches about 28 kPa (4 psi). Page 4457 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Diagram Information and Instructions Cruise Control Servo: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 3110 EGR Valve: Specifications EGR Valve Torque EGR Valve Torque EGR Valve to Intake Manifold 17 ft.lb Introducing the GM PROM Cross Reference Index PROM - Programmable Read Only Memory: Application and ID Introducing the GM PROM Cross Reference Index This PROM cross reference index provides tables that let you use a PROM identification (ID) code to identify the PROM installed in the engine control module (ECM) on most GM vehicles. The code can be either - or both - the internal "scan ID" code or the external PROM code. From the PROM identification, you can find the part number of the PROM and trace the PROM history to determine if any revised PROM's have been issued to supersede the one in the vehicle. The PROM history for a specific vehicle lists a succession of superseding PROM's ending with the most recent PROM released as a service part for the vehicle. PROM's that were released as service parts and explained in a technical service bulletin (TSB) are listed with a description of why the PROM was issued. In most cases, the applicable TSB also is referenced. This index lists ECM PROM's for the 1980-95 vehicles. It does not contain ID codes and part numbers for all PROM's used in all GM vehicles. NOTE: GM flash PROM's (EEPROM's) can only be updated at GM Dealerships with factory-supplied equipment. These cars will not display a PROM ID. By following the steps outlined below, you can use the PROM index to determine if the problem you are diagnosing can possibly be corrected by installing a revised PROM. The PROM index tables are organized by model year, engine displacement, and engine code (the eighth digit of the Vehicle Identification Number). The table columns are arranged as shown below: Example of Table Column Arrangement SCAN PROM PROM PART SUPERSEDING TSB REFERENCE ID CODE (BCC) NUMBER ID PART NUMBER NUMBER (1) (2) (3) (4) (5) .............................................................................................................................................................. ........................................................................ 9461 8958 AMU 16058955R 8290 01228290 86194 Column 1, SCAN ID: The scan ID is the internal PROM identification number transmitted on the ECM data stream and displayed by the scanner as PROM ID. The PROM records for each year and engine are listed numerically by this scan ID. Column 2, PROM CODE: These are the numbers and letters marked on the top of the PROM itself. The numbers are often referred to as the "external PROM ID." The letters are often called the "broadcast code." Together they are the external PROM code. Column 3, PROM P/N: This is the GM part number for the PROM identified by the codes in columns 1 and 2. Column 4, SUPERSEDING ID PROM PART NUMBER: Use the superseding scan ID to locate the newer PROM in the table. If the scan ID for the superseding PROM is not known, the PROM broadcast code is listed here. If the PROM is superseded by a newer PROM, that part number is listed here. Column 5, TSB REFERENCE NUMBER The TSB NUMBER column identifies the original TSB that released this PROM for service. Whenever possible you should refer to the TSB for additional information before changing a PROM. The bulletin may list other parts that must be installed when the PROM is changed, or it may provide additional troubleshooting information. To find a TSB, see Reading Technical Service Bulletins. See: Reading Technical Service Bulletins This will display all the TSB's for that particular vehicle. EXPANDED FOOTNOTES Here you will find SUPERSEDING SCAN ID, PROM PART NUMBERS, symptoms and additional parts that need to be replaced when servicing the PROM. Booster Assembly Vacuum Brake Booster: Service and Repair Booster Assembly Single Diaphragm Type Disassembly Fig. 3 Exploded View Of Delco-Moraine Single Diaphragm Brake Booster Components Fig. 4 Brake Booster Holding Fixture 1. Remove boot, silencer, vacuum check valve, grommet and front housing seal, Fig. 3. 2. Scribe a line across front and rear housing, then mount brake booster to brake mounting fixture tool No. J 23456 or equivalent, Fig. 4. 3. Turn fixture handle counterclockwise to unlock housings. 4. Remove return spring, power piston assembly and power piston bearing from rear housing, Fig. 3. 5. Remove reaction body retainer, piston rod, reaction retainer and filter, Fig. 3. 6. Remove power piston and pushrod assembly as follows: a. While holding the pushrod down against a hard surface, grasp outside edge of diaphragm support and diaphragm, Fig. 3. b. Use a slight force to dislodge diaphragm retainer, Fig. 3. 7. Remove diaphragm from diaphragm support, Fig. 3. 8. Inspect all parts for corrosion, nicks, cracks, cuts, scoring, distortion or excessive wear. Replace as necessary. 9. Clean all parts in denatured alcohol. Dry with clean compressed air. Do not immerse power piston and pushrod assembly in alcohol. Assembly Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Page 5305 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 2535 MAP Circuit (VCM) VCM Circuit Page 6256 Compressor Shaft Seal: Service and Repair With HR6-HE Compressor Seal Leak Detection A shaft seal should not be changed because of small amounts of oil found on an adjacent surface but only after actual refrigerant leakage is found using an approved leak detector, J 29547 or equivalent. Remove or Disconnect 1. Recover the refrigerant. 2. Loosen and reposition compressor in mounting brackets, if necessary. 3. Remove clutch plate and hub assembly from compressor as described in minor repairs. Removing Or Installing Shaft Seal Retaining Ring 4. Remove the shaft seal retainer ring, using snap ring pliers J 5403. 5. Thoroughly clean inside of compressor neck area surrounding the shaft, the exposed portion of the seal, the retainer ring groove and the shaft itself. Any dirt or foreign material getting into compressor may cause damage. Page 7329 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Page 4463 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 2748 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature (ECT) Sensor Engine Coolant Temperature (ECT) W Engine Wiring, RH Side Page 6745 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 6198 Removing Pulley Rotor And Bearing Assembly 3. Install pulley rotor and bearing puller guide 3 33023-A to the front head and install J 33020 pulley rotor and bearing puller down into the inner circle of slots in the rotor. Turn the J 33020 puller clockwise in the slots in the rotor. 4. Hold the J 33020 puller in place and tighten the puller screw against the puller guide to remove the pulley rotor and bearing assembly. 5. To prevent damage to the pulley rotor during bearing removal the rotor hub must be properly supported. Pulley Rotor Bearing Removal Remove the forcing screw from J 33020 puller and, with the puller tangs still engaged in the rotor slots, invert the assembly onto a solid flat surface or blocks. 6. Drive the bearing out of the rotor hub with rotor bearing remover J 9398-A and J 29886 universal handle. NOTICE: It is not necessary to remove the staking in front of the bearing to remove the bearing, however, it will be necessary to file away the old stake metal for proper clearance for the new bearing to be installed into the rotor bore or the bearing may be damaged. Install or Connect Page 3839 interchangeable. Important: The wear plate (640) and input thrust washer (660) are not required with the new sprag. Use of the thrust washer and wear plate with the new sprag assembly will cause a misbuild (correct end play cannot be obtained). Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Paint - Acid Rain Damage to Base Coat/Clear Coat Paint: All Technical Service Bulletins Paint - Acid Rain Damage to Base Coat/Clear Coat Number: 92-33-10 Section: 10 Date: NOV. 1991 Corporate Bulletin No.: 131060 ASE No.: B2 Subject: INDUSTRIAL FALLOUT/RAIL DUST DAMAGE TO BASE COAT/CLEAR COAT Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS Application: 1992 (and previous) models with Base Coat/Clear Coat Paint The following information regards the use of finesse type repairs to environmental (industrial fallout) and rail dust damage of base coat/clear coat paint finishes. Since the severity of the condition varies from area to area, PROPER DIAGNOSIS of the damage extent is CRITICAL TO THE SUCCESS OF REPAIRS. Diagnosis should be performed under high intensity fluorescent lighting, on horizontal surfaces (hood, roof, decklid) after they have been properly cleaned. INDUSTRIAL FALLOUT (ACID RAIN) There are three basic types of acid rain damage: Surface level contamination, - may be repaired by simply washing the vehicle, cleaning the surface with a wax and grease remover, neutralizing acidic residue and finesse polishing. - Clearcoat etching, - slight etching still noticeable after the above washing and finesse polishing procedure. - Basecoat etching, - severe etching beyond the clearcoat into the basecoat. PROCEDURES FOR SURFACE LEVEL CONTAMINATION REPAIRS 1. Wash the vehicle with standard car detergent and water and dry thoroughly. 2. Clean the affected area with a wax and grease remover. 3. Neutralize any left over acidic residue by cleaning the damaged areas with a mixture of baking soda and water (one tablespoon per quart of water), rinse THOROUGHLY and dry the panels completely. 4. Apply a finesse type polish with a foam pad. CLEAN AND INSPECT THE SURFACE A. If the damage has been repaired, remove any swirl marks with a dual action orbital polisher and foam pad. B. If some damage remains, proceed to step 5. SLIGHT CLEARCOAT DAMAGE - WET SANDING, FINESSE POLISHING 5. Select a small test area on a damaged panel. 6. Wet sand the damaged area with an American Grade ultra fine sandpaper of 1,500 to 2,000 grit and a rubber sponge sanding block. During the wet sand process; a. Use ample amounts of water b. Go slow to prevent removing too much clearcoat. Note: Be sure to use American Sandpaper. European Sandpaper has a "P" before the grit number and European grits do not align with American grits the majority of the time. 7. Remove the excess water with a rubber squeegee and inspect the area. A. If this has repaired the damage, continue the sanding procedure on the entire panel, apply a finesse type polish with a foam pad and remove any swirl marks with a dual action orbital polisher and foam pad. B. If (during the repair) it is suspected or observed that; - etching has penetrated into the base coat OR - too much clearcoat has been removed during sanding OR - base color is transferred to pad during polishing, Page 7440 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 7410 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Rocker Arm Studs Replace Rocker Arm Assembly: Service and Repair Rocker Arm Studs Replace Fig. 10 Rocker Arm Stud Removal Fig. 11 Reaming Of Rocker Arm Stud Bore Fig. 12 Installing Rocker Arm Stud Rocker arm studs that have damaged threads or are loose should be replaced with oversize studs. Oversize studs are available in .003 and .013 inch and can be installed after properly reaming the holes as follows: 1. Remove stud using stud reamer tool No. J-5802-01, Fig. 10 or equivalent with a nut and flat washer placed over the tool. 2. Ream hole to proper size using reamer tool No. J-5715, Fig. 11 for .003 inch oversize or reamer tool No. J-6036 for .013 inch oversize. Do not install oversize stud without reaming hole since cylinder head damage could occur. 3. Apply axle lubricant to press fit area of stud and install using stud installer tool No. J-6880 or equivalent, Fig. 12. Page 2484 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature (ECT) Sensor Engine Coolant Temperature (ECT) W Engine Wiring, RH Side Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Locations Malfunction Indicator Lamp: Locations Instrument cluster. Page 4677 Brake Rotor/Disc: Fundamentals and Basics How to Use A Micrometer CONSTRUCTION The spindle on a micrometer is moved in or out by rotating the thimble or ratchet. The thread pitch on the spindle is 40 threads per inch. A single full rotation of the thimble extends or retracts the spindle one thread or 1/40 of an inch (0.025, 25 thousands). The thimble is divided into 25 equal divisions. Rotating the thimble one division will extend or retract the spindle 1/25 of a thread. (1/25) x (1/40)inch = 1/1000 inch (0.001), one division on the thimble is equal to 0.001 inches. HOW TO READ As the thimble is rotated out it uncovers a scale on the sleeve. Each major division on the scale is 1/10 of an inch (0.100) Each major division is separated into 4 minor divisions, each equal to 25/1000 of an inch (0.025). Page 525 Page 2378 Temperature Gage Indicates Cold All The Time Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Page 7568 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 2630 Idle Speed: Adjustments NOTE: Before performing this check: - Verify no codes displayed. - Idle air control system has been checked. - Ignition timing is correct. CONTROLLED IDLE SPEED CHECK - Set parking brake and block drive wheels. - Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. - START engine and bring it to normal operating temperature. - Check for correct state of PARK/NEUTRAL switch on SCAN tool. - Check specifications chart for controlled idle speed and IAC valve pintle position (counts). - If within specifications, the idle speed is being correctly controlled by the control module. - If not within specifications, refer to DIAGNOSIS BY SYMPTOM. See: Fuel Delivery and Air Induction/Testing and Inspection MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable on this engine. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Auto D 550 5-40 CL [1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). Page 1299 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 763 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 1675 1. Balance shaft rear bearing using J 38834. - Dip the bearing in clean engine oil before installation. - Install the bearing with the flat edge and the manufacturers markings facing the front of the engine. 2. Balance shaft into the block using J 36996 and J 8092. - Dip the front balance shaft bearing into clean engine oil before assembly. Seat Dimensions Valve Seat: Specifications Seat Angle 46 deg Seat Width Intake 0.035-0.060 in Exhaust 0.062-0.093 in Runout 0.002 in Page 7550 Symbol Identification Page 950 Distributor: Service and Repair Distributor Shaft, Pole Piece & Pickup Coil Typical Distributor Components REMOVE/DISCONNECT 1. With distributor removed, disconnect wires at module terminals 2. Roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. INSTALL/CONNECT 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Page 5174 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Removal Brake Pad: Service and Repair Removal Caliper Assembly 1. Remove caliper assembly. See Brake Caliper / Service and Repair. See: Brake Caliper/Service and Repair 2. Remove inboard pad. Dislodge outboard pad and position caliper on the front suspension so the brake hose will not support the weight of the caliper. CAUTION: Do not allow caliper to hang from brake hose. 3. Remove pad support spring from piston. 4. Remove two sleeves from inboard ears of the caliper. 5. Remove four rubber bushings from the grooves in each of the caliper ears. Page 6102 Blower Motor Case Assembly REMOVE OR DISCONNECT 1. Engine coolant. - Drain enough coolant into a clean container to lower the coolant level below the level of the lowest heater hose fining. 2. Electrical connectors from blower motor (53) and resistor (80). 3. Blower motor (53). 4. Ground strap. 5. Heater hoses (72 and 70). 6. Screws (84). 7. Nuts (86). 8. Blower case (49) and seal (51). INSTALL OR CONNECT 1. Blower case (49) and seal (51). NOTICE: For steps 2 and 3, refer to "Fasteners" under "Vehicle Damage Warnings." 2. Screws (84). - Tighten screws (84) to 3 Nm (27 in. lb.). 3. Nuts (86). - Tighten nuts (86) to 3 Nm (27 in. lb.). 4. Heater hoses (72 and 70). 5. Ground strap. Page 8374 Rear Park And Marker Lamps A/T Control - DTC P0756 Diagnostic Tips Channel Plate: Technical Service Bulletins A/T Control - DTC P0756 Diagnostic Tips INFORMATION Bulletin No.: 01-07-30-036H Date: January 29, 2009 Subject: Diagnostic Tips for Automatic Transmission DTC P0756, Second, Third, Fourth Gear Start Models: 2009 and Prior GM Passenger Cars and Light Duty Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with 4L60-E, 4L65-E or 4L70E Automatic Transmission (RPOs M30, M32 or M70) Supercede: This bulletin is being revised to add the 2009 model year and add details regarding spacer plates. Please discard Corporate Bulletin Number 01-07-30-036G (Section 07 - Transmission/Transaxle). Some dealership technicians may have difficulty diagnosing DTC P0756, 2-3 Shift Valve Performance on 4L60-E, 4L65-E or 4L70E automatic transmissions. As detailed in the Service Manual, when the PCM detects a 4-3-3-4 shift pattern, DTC P0756 will set. Some customers may also describe a condition of a second, third or fourth gear start that may have the same causes but has not set this DTC yet. Below are some tips when diagnosing this DTC: ^ This is a performance code. This means that a mechanical malfunction exists. ^ This code is not set by electrical issues such as a damaged wiring harness or poor electrical connections. Electrical problems would cause a DTC P0758, P0787 or P0788 to set. ^ The most likely cause is chips/debris plugging the filtered AFL oil at orifice # 29 on the top of the spacer plate (48). This is a very small hole and is easily plugged by a small amount of debris. It is important to remove the spacer plate and inspect orifice # 29 and the immediate area for the presence of chips/debris. Also, the transmission case passage directly above this orifice and the valve body passage directly below should be inspected and cleaned of any chips/debris. For 2003 and newer vehicles the spacer plate should be replaced. The service replacement spacer plate is a bonded style with gaskets and solenoid filter screens bonded to the spacer plate. These screens can help to prevent plugging of orifice # 29 caused by small debris or chips. ^ This code could be set if the 2-3 shift valve (368) were stuck or hung-up in its bore. Inspect the 2-3 shift valve (368) and the 2-3 shuttle valve (369) for free movement or damage and clean the valves, the bore and the valve body passages. ^ This code could be set by a 2-3 shift solenoid (367b) if it were cracked, broken or leaking. Refer to Shift Solenoid Leak Test in the appropriate Service Manual for the leak test procedure. Based on parts return findings, a damaged or leaking shift solenoid is the least likely cause of this condition. Simply replacing a shift solenoid will not correct this condition unless the solenoid has been found to be cracked, broken or leaking. It is important to also refer to the appropriate Service Manual or Service Information (SI) for further possible causes of this condition. Disclaimer Page 4276 Pinion Bearing: Adjustments Dana/Spicer Fig. 5 Pinion setting chart If original ring gear and pinion assembly are to be reused, measure original shim pack and build a new shim pack to the same dimension. If baffle is in the axle assembly, it is considered part of the shim pack. Ring gears and pinions are supplied in matched sets only. If a new gear is being used, verify numbers on pinion and ring gear before proceeding with assembly. On the button end of the pinion there is a ``+'', `` - '', or ``0'' number which indicates the best running position for each particular gear set. This position is controlled by shims installed behind the inner bearing cup. If baffles or oil slingers are used, they are considered part of the adjusting shim pack. If a new gear set is being installed, note the plus or minus mark on both old and new pinions and adjust thickness of shim pack to compensate for the difference between these two numbers. Refer to chart, Fig. 5, when determining shim size. 1. Install inner shim pack and, on 9-3/4 inch ring gear axle, the oil slinger in inner or rear cup bore, then drive cup into position using suitable tool. 2. Add or remove an equal amount to the outer shim pack as was added to the inner shim pack. 3. Drive outer cup into carrier bore, then press rear pinion bearing onto pinion shaft. 4. Install drive pinion and bearing into differential carrier. 5. Install shims and outer or front pinion bearing. 6. Install companion flange, then the washer and nut on pinion shaft. Torque nut to 250 ft. lbs. with a suitable holding bar in place. 7. Remove holding bar, then measure rotating torque of pinion shaft. Rotating torque should measure 10-20 inch lbs. with original bearings installed, or 20-40 inch lbs. with new bearings installed, discounting torque required to start turning shaft. 8. If rotating torque is not within specifications, adjust shim pack as necessary. Increase outer shim pack to reduce torque, or decrease shim pack to increase torque. 9. Remove nut, washer and companion flange from pinion shaft. 10. Install oil slinger, gasket (if equipped) and oil seal onto pinion shaft. 11. Install companion flange, washer and nut and torque nut to 250 ft. lbs. Page 5179 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Lighting - Exterior Lamp Condensation and Replacement Turn Signal Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Turbo Hydra-Matic 3L30 (180C) Fluid - A/T: Service and Repair Turbo Hydra-Matic 3L30 (180C) Draining Bottom Pan 1. Raise and support vehicle. 2. Position a suitable drain pan below transmission oil pan. 3. Remove front and side oil pan bolts. 4. Loosen rear bolts and gently pry the pan down to allow fluid to drain. 5. Remove remaining bolts and pull pan away from case carefully, as there will still be fluid contained in the pan. 6. Drain remaining fluid from pan, then remove gasket, oil filter retaining bolts, oil filter and seal. 7. Using solvent, thoroughly clean oil pan and gasket surfaces, then air dry. 8. Install new oil seal and filter into case. Torque attaching bolts to 13-15 ft. lbs. 9. Install oil pan with new gasket and torque bolts to 7-10 ft. lbs. 10. Add transmission fluid, then with engine idling and brakes applied, move selector lever through each gear range and return selector lever to Park. 11. Bring fluid to proper operating temperature and check fluid level, adding as required to bring level to the Full mark. Adding Fluid to A Dry Transmission 1. Add transmission fluid. 2. With transmission in Park, start engine and let engine idle (carburetor off fast idle cam.) 3. Apply brakes and move shifter lever through each gear range, then with transmission in Park, add additional fluid as required to bring the level up to Full mark on dipstick. Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge: Customer Interest Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Specifications Hose/Line HVAC: Specifications Refrigerant Hose-to-Condenser .............................................................................................................................................................. 24 Nm (18 ft. lbs.). Refrigerant Hose-to-Compressor Bolt ................................................................................................................................................... 34 Nm (25 ft. lbs.). Refrigerant Hose-to-Accumulator .......................................................................................................................................................... 41 Nm (30 ft. lbs.). A/C Compressor Seal Washer - Reference Chart Compressor Shaft Seal: Technical Service Bulletins A/C Compressor Seal Washer - Reference Chart File In Section: 1 - HVAC Bulletin No.: 63-12-15 Date: November, 1996 INFORMATION Subject: Reference Chart for A/C Compressor Seal Washers Models: 1997 and Prior Passenger Cars (Except Corvette and GEO) 1997 and Prior Light Duty Trucks (Except Tracker) GMSPO A/C compressors include a seal washer kit. These kits contain various color edge painted washer seals and inserts in which only two (2) washers and possibly one (1) insert are used. It has come to our attention that some packaging discrepancies were found and some of the seals cannot be properly identified for installation. These seals are very close in size and some of the seals were inadvertently edge painted the wrong color or not painted. Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Page 3451 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Page 2820 Idle Air Control (IAC) System Circuit Circuit Description: The ECM controls idle rpm with the IAC valve. To increase idle rpm, the ECM moves the IAC valve away from it's seat, allowing more air to pass by the throttle plate. To decrease rpm, it moves the IAC valve toward it's seat, reducing air flow by the throttle plate. A Tech 1 "Scan" tool will read the ECM commands to the IAC valve in counts. The higher the counts, the more air allowed (higher idle). The lower the counts, the less air allowed (lower idle). Test Description: Number(s) below refer to circled number(s) on the diagnostic chart. 1. The IAC tester is used to extend and retract the IAC valve. Valve movement is verified by an engine speed change. If no change in engine speed occurs, the valve can be retested when removed from the throttle body. 2. This step checks the quality of the IAC movement in Step 1. Between 700 rpm and about 1500 rpm, the engine speed should change smoothly with each flash of the tester light in both extend and retract. If the IAC valve is retracted beyond the control range (about 1500 rpm), it may take many flashes in the extend position before engine speed will begin to drop. This is normal on certain engines, fully extending the IAC may cause engine stall. This may be normal. 3. Steps 1 and 2 verified proper IAC valve operation while this step checks the IAC circuits. Each lamp on the node light should flash red and green while the IAC valve is cycled. While the sequence of color is not important if either light is "OFF" or does not flash red and green, check the circuits for faults, beginning with poor terminal contacts. IAC VALVE RESET PROCEDURE: ^ Ignition "OFF" for 10 seconds. ^ Start and run engine for 5 seconds. ^ Ignition "OFF" for 10 seconds. Diagnostic Aids: A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be overcome by the IAC valve. Out of control range IAC Tech 1 "Scan" tool counts will be above 60 if idle is too low, and zero counts if idle is too high. The following checks should be made to repair a non-IAC system problem. ^ Vacuum Leak (High Idle) - If idle is too high, stop the engine. Fully extend (low) IAC with tester. Start engine. If idle speed is above 800 rpm, locate and correct vacuum leak including PCV system. Also cheek for binding of throttle blade or linkage. ^ System too lean (High Air/Fuel Ratio) - The idle speed may be too high or too low. Engine speed may vary up and down and disconnecting the IAC valve does not help. Code 44 may be set "Scan" 02 voltage will be less than 300 mV (.3 volt). Check for low regulated fuel pressure water in the fuel or a restricted injector. ^ System too rich (Low Air/Fuel Ratio), - The idle speed will be too low. "Scan" tool IAC counts will usually be above 80. System is obviously rich and may exhibit black exhaust smoke. Tech 1 "Scan" tool 02 voltage will be fixed above 800 mV (.8 volt). Check for high fuel pressure, leaking or sticking injector. Silicone contaminated 02 sensors "Scan" voltage will be slow to respond. ^ Throttle body - Remove IAC and inspect bore for foreign material. ^ A/C Compressor - Refer to "A/C Diagnosis" if circuit is shorted to ground. If the relay is faulty, idle problem may exist. ^ If intermittent poor driveability symptoms are resolved by disconnecting the IAC, carefully recheck connections, valve terminal resistance, or replace IAC. Page 393 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 8575 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 1166 85-89 - 97104794 90-93 - 97104793 Adapter, Low Side: Part of Hose Asm. 0-rings: Receiver/dryer 85-91 - 94154048 92-93 - 94461700 Switch/pipe - 94461902 Suction hose: 85-86: 1.5L - 97104799; 1.6L - 97104800 90-93: 1.6L - 97104801; 1.8L - 97104803 B. General Information Several items affecting the performance and durability of the system should be considered: 1. Performance When performed properly, the retrofit from R-12 to R-134a will have minimal effect on the system's performance in most climatic conditions found in the United States and Canada. 2. Leakage Experience has shown that most leakage in an A/C system is due to leaks at the joints, or through a small leak in a hose, usually at the coupling. The R-134a molecules are smaller than R-12, and a small leak may result in a faster loss of refrigerant with R-134a. Because of this, it is very important to leak check all vehicles using the J 39400 leak detector, BEFORE the retrofit is performed, and repair any leaks found. "0" rings and hoses used in most GM vehicles are compatible with R-134a and do not need replacement during a retrofit. "0" rings or hoses installed in previous repairs may have been of non-compatible materials if GM parts were not used and will be more likely to deteriorate and leak than the original equipment materials. All "0" rings and hoses available through GMSP0 are compatible with R-134a. Remember that the normal policy is to replace the "0" rings whenever a joint is opened for any reason. 3. Desiccant You may have heard that the currently used desiccant in the accumulator is not compatible with R-134a. Extensive testing has shown that it is, in fact, suitable for use with R-134a, once it has been in service in an R-12 system. The accumulator in these models will not have to be changed during the retrofit procedure, unless the vehicle is more than 5 years old. Vehicles more than 5 years old should have the A/D replaced to add new desiccant for proper system drying. In the event that an accumulator/dryer (A/D) needs to be replaced on a retrofitted system in the future, only A/D's with XH-7 desiccant should be used. The service parts for the 1993 vehicles contain only XH-7 desiccant. The parts for the 1992 and older vehicles may contain either XH-5 or XH-7. Parts containing XH-7 can be identified (see Figure 1) by 1) an "A" printed on the top of the A/D; or 2) if there is a label on top of the A/D, there will be a square with an "A" inside; or 3) if there is a time code and date printed on top of the A/D just under the "Harrison" logo, the A/D contains XH-7. A/D's containing XH-5 can still be used on R-12 vehicles. 4. Improved Cooling Performance There have been service bulletins issued in the past with information improving the cooling performance of existing R-12 systems. These bulletins can also be used to improve the performance of retrofitted vehicles in high ambient temperature climates. 5. PAG or V5 Oil Compatibility Contrary to information published to date outside of General Motors, mineral oil and PAG or V5 oil ARE chemically compatible. The mineral oil left in the system after reclaiming the R-12 can remain in the system with no harmful effects. However, the mineral oil will not mix with the R-134a, and so will not circulate and perform its lubricating function. Testing has shown that most of the mineral oil will eventually collect in the Page 3482 Install TPS onto replacement throttle body assembly. Refer to THROTTLE POSITION SENSOR (TPS). INSTALLATION: 1. Install new throttle body to fuel meter body gasket. 2. Install fuel meter body assembly on throttle body assembly. 3. Install fuel meter body to throttle body attaching screws that have been coated with locking compound. Tighten the attaching screw assemblies to 4.0 Nm (3.50 lb-in). 4. Install TBI unit onto intake manifold. Tighten mounting bolts to 16.0 Nm (12.0 lb-ft). Page 7552 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Locations Electronic Spark Control (ESC) Module Page 5083 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 6035 Wheel Bearing: Service and Repair REAR WHEEL BEARINGS AND/OR HUB Fig. 2 Axle Shaft Bearing Removal Fig. 3 Axle Shaft Bearing Installation Fig. 4 Axle Shaft Seal Installation 1. Remove axle shaft as described under AXLE SHAFT. 2. Remove axle seal by prying behind seal steel case with a pry bar. Use caution to avoid damaging axle housing. 3. Using a puller and slide hammer, remove axle bearing, Fig. 2. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer No. tool J-23765, or equivalent, until bearing is seated in housing, Fig. 3. 5. Lubricate seal lips with gear lubricant, then position seal on axle shaft seal installer tool No. J-23771 or equivalent, and install in axle housing, tapping into place until seal is flush with axle housing, Fig. 4. 6. Reinstall axle shaft. Page 5758 Suspension Strut / Shock Absorber: Service and Repair Rear Suspension Fig. 6 Shock Absorber Mounting 1. Raise vehicle and place jack stands under frame side rails. Position a jack under the rear axle housing and raise slightly to support axle assembly. 2. Disconnect shock absorber from upper mounting location, Fig. 6. 3. Disconnect shock absorber attaching nut from spring anchor plate. 4. Remove shock absorber. 5. Reverse procedure to install. Torque upper and lower mounting nuts to specifications. Page 5385 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 5461 Relay Box: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 748 Neutral Safety Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Service and Repair Crankcase Filter: Service and Repair Inspection The crankcase ventilation system should be checked every 30,000 miles and also during regular engine tune-ups. If the crankcase ventilation system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the crankcase ventilation valve or air cleaner is replaced. When a periodic inspection indicates the crankcase ventilation is not functioning properly, it should be serviced by replacement only. Spark Plug Gap, Torque and Type Spark Plug: Specifications Spark Plug Gap, Torque and Type Spark Plug Gap ................................................................................................................................... ...................................................... 1.14 mm (.045 ") Spark Plug Torque ............................................................................................................................... ...................................................... 15 N-m (11 lb.ft.) Spark Plug Type .................................................................................................................................. ............................................................. AC CR43TS NOTE Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Specifications Pressure Plate: Specifications Clutch Cover to Flywheel bolts ............................................................................................................ ................................................................... 30 ft. lbs. Page 2964 Oxygen Sensor: Specifications Sensor Voltage Range Sensor Voltage Range Sensor Voltage (Closed Loop) 0.1 to 1.0 V Page 8280 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 6478 Vacuum Reservoir HVAC: Service and Repair Engine Vacuum Line Routing NOTE: The vacuum tank is installed on the left front (driver's side) wheel fender in the engine compartment. REMOVE OR DISCONNECT 1. Vacuum hose (56). 2. Screws. 3. Tank (55). INSTALL OR CONNECT 1. Tank (55). 2. Screws. - Tighten screws to 3 Nm (27 in. lb.). 3. Vacuum hose (56). Page 7174 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 2808 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 7741 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Connector C1 ECM Connector C1 Page 5667 Fig. 7 Stub shaft pin disengage 8. Remove adjuster nut, then remove adjuster plug using spanner wrench tool J-7624 or equivalent, Fig. 4. 9. Disassemble adjuster plug as follows: a. Remove retaining ring, washer, seal and bearing. b. Remove bearing retainer by prying at raised area, then remove seal and needle bearing with adjuster plug bearing installer tool J-8524-2 and driver tool J-7079-2 or equivalents, Fig. 5. 10. Remove valve and worm shaft as an assembly with both races and bearing. Separate as follows: a. Remove worm shaft from valve body, Fig. 6. b. Remove races and bearing from worm shaft, them remove seal. 11. Remove stub shaft from valve body as follows: a. Hold assembly and lightly tap stub shaft against a bench until shaft cap is free from valve body, Fig. 7. b. Pull shaft assembly until shaft cap clears valve body by approximately 1/4 inch. c. Remove valve spool and seals. 12. Remove screws, clamp and ball guide from rack piston, then remove balls. 13. Remove connectors from housing. Assembly Fig. 8 Connector installation Page 2458 Fuel Pump Relay: Service and Repair Relay Center 2.5L,2.8L S REMOVE/DISCONNECT - Verify that ignition switch is in the "OFF" position. - Retainer, if installed. - Electrical connector. - Fuel pump relay by depressing bracket clip at rear of relay, or removing bolts from retaining bracket. INSTALL/DISCONNECT - Fuel pump relay. - Electrical connector. - Retainer. - Verify correct operation to confirm repair. Page 2031 Parts are currently available from GMSPO. Calibration Information for 1992 Model Year Vehicles with Sleeve Bearing Engines: Torque Specifications M/T - Clutch Pilot Bushing and Bearings Pilot Bearing: All Technical Service Bulletins M/T - Clutch Pilot Bushing and Bearings File In Section: 7 - Transmission Bulletin No.: 46-73-02 Date: October, 1994 INFORMATION Subject: Clutch Pilot Bushings and Bearings Models: 1988-95 Chevrolet and GMC Truck Light Duty Trucks with 4.3L, 5.0L, 5.7L, 6.2L, 6.5L, 7.4L Engines and Manual Transmission A worn or damaged clutch pilot bushing or bearing, located in the end of the crankshaft, can be the cause of various clutch and transmission concerns including: ^ Noise when the clutch pedal is depressed ^ Transmission noise ^ Clutch shudder on launch ^ Difficult shifting or excessive clash into reverse A worn clutch pilot bushing will not properly support the transmission input shaft. Without sufficient support, the front of the input shaft can move out of location resulting in transmission noise or clutch shudder on engagement. A damaged clutch pilot bushing or bearing may continue to turn the transmission input shaft when the clutch is released. This rotation can then cause difficult shifting or gear clash. Anytime a transmission or clutch is removed for repair, a new clutch pilot roller bearing should be installed. The end of the transmission input shaft that contacts the pilot roller bearing should also be inspected for damage. When installing the pilot roller bearing, the chamfer or lead-in to the I.D. should be installed facing the rear of the vehicle. This chamfer will help guide the input shaft into the roller bearing. This bearing is pre-lubed with a high temperature grease and does not require additional lubrication. The bearing listed below will fit all 1988-95 4.3L, 5.OL, 5.7L, 6.2L, 6.5L, and 7.4L light duty engines. Do not use a bronze clutch pilot bushing. Parts Information P/N Description Qty 14061685 Bearing, clutch Pilot 1 Parts are currently available from GMSPO. Page 5107 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Wheels (Steel) - Damage Due to Improper Mounting Wheels: All Technical Service Bulletins Wheels (Steel) - Damage Due to Improper Mounting Number: 92-232-3E Section: 3E Date: JUNE 1992 Corporate Bulletin No.: 233002 ASE No.: A4 Subject: AVOIDING DAMAGE TO STEEL WHEELS FROM IMPROPER WHEEL/TIRE CHANGING TECHNIQUES Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH STEEL WHEELS It is important to use proper procedures to prevent damage to either the tire mounting surface or the wheel mounting holes. Damage can result from the improper wheel attachment or tire mounting techniques on vehicles with steel wheels. 1. IMPROPER TIRE CHANGING TECHNIQUES: It takes about 70 seconds for the air to completely exhaust from a large tire. If the technician doesn't wait this amount of time after removing the valve core, the bead breaker on the tire change could put enough force on the tire to bend the wheel at the mounting surface. Such damage can result in vibration, shimmy, and under severe usage (i.e. police vehicle) lead to cracking. 2. OVER TORQUING OF THE WHEEL NUTS: The service specification for wheel nuts is listed in the Service Manuals. Some wheels have been observed with wheel nuts that were over torqued by as much as 50 percent. This may damage the wheel mounting holes and may also lead to cracks. I. PROPER TIRE CHANGING TECHNIQUES: Completely deflate the tire before attempting to break the tire bead loose. MOUNTING SURFACE CHECKING PROCEDURE Locations Electronic Spark Control (ESC) Module Page 5479 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Campaign - 02-313 Stop Delivery Notice Update Fuel Level Sensor: All Technical Service Bulletins Campaign - 02-313 Stop Delivery Notice Update ** ADMINISTRATIVE MESSAGE 01-277 CREATED ON 9/5/91 AT PAGE 1 OF 1 TO: ALL CHEVROLET DEALERS SUBJECT: STOP DELIVERY NOTICE 1992 S/T TRUCKS THIS IS WITH FURTHER REFERENCE TO THE 1992 S/T TRUCK STOP DELIVERY DCS ADMIN MESSAGE 01-258 DATED 8/22/91 SENT TO ALL CHEVROLET DEALERS. SELECT DEALERS WERE ADVISED IN DCS MESSAGE 02-313 DATED 9/5/91 OF PRODUCT CAMPAIGN 92C02 FUEL LEVER SENDER ARM/TANK INTERFERENCE. THIS DCS INCLUDED INVOLVED DEALER CODES AND INVOLVED VIN'S. ANY DEALER NOT RECEIVING DCS ADMIN MESSAGE 02-313 HAS NO INVOLVED VEHICLES ASSIGNED AND VIN'S WHICH FALL WITHIN THE ORIGINAL VIN RANGES LISTED BELOW ARE RELEASED FROM THE STOP DELIVERY. ASSEMBLY PLANT STARTING VIN ENDING VIN PONTIAC WEST N0100014 N0101228 MORAINE N2100052 N2101700 SHREVEPORT N8100014 N8101560 PLEASE COMMUNICATE THIS INFORMATION TO ALL DEALERSHIP MANAGEMENT IMMEDIATELY UPON RECEIPT. Page 6728 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Locations Timing Mark Engine - Miss, Hesitation, or Roughness Spark Plug Wire: Customer Interest Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Body - Vehicle Glass Distortion Information Front Door Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 1321 Relay Box: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 4862 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 7566 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 2955 Manifold Pressure/Vacuum Sensor: Description and Operation Map Sensor Circuit (GM Generic) Manifold Absolute Pressure (MAP) Sensor PURPOSE The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. As intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the control module to automatically adjust for different altitudes. The PCM uses information from the MAP sensor to calculate spark advance and fuel as follows: Low MAP output voltage (low pressure) results in more spark advance. - High MAP output voltage (high pressure) results in less spark advance. - Low MAP output voltage (low pressure) results in less fuel. - High MAP output voltage (high pressure) results in more fuel. OPERATION The control module supplies a 5 volt reference signal to the MAP sensor and the sensor provides a path to ground through its variable resistor. The control module by monitoring the sensor output voltage can determine the manifold pressure. A closed throttle on engine coastdown will produce a relatively low MAP output, while a wide open throttle will produce a high output. At higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum. At lower pressure output voltage will be about 1 to 2 volts at idle. A failure in the MAP sensor circuit should set Diagnostic Trouble Codes (DTC) 33 or 34 with PCM/ECM systems and DTC P0107 or P0108 with VCM systems. Page 6381 Page 7948 Oil Pressure Gage Is Inaccurate Locations Audio Alarm Module: Locations On Convenience Center Page 4636 Brake Bleeding: Fundamentals and Basics BENCH BLEEDING Why A master-cylinder will develop little or no pressure if air is trapped in cylinder bore. Normal brake bleeding will not remove air trapped within the master-cylinder. How Clamp the master-cylinder securely in a vice. It is usually best to clamp the side of the vice onto the flat surface that is used to secure the master-cylinder to the brake booster. There are two basic methods for bleeding master-cylinder, one utilizes stroking the master-cylinder to expel air from the cylinder bore while the other utilizes a large syringe to backflush fluid from the outlet ports to the reservoir. Stroking Fill the master-cylinder with clean brake fluid. - The brake line fittings on the master-cylinder should be capped or plugged. NOTE: Special "bench bleeding" plastic fittings are available which allow for recirculating the brake fluid back into the reservoir. - Using a dull object, slowly stroke the master-cylinder piston, air and brake fluid will be expelled from the brake line fittings. Prior to releasing the piston plug or cap the outlet ports. - Repeat this procedure 8-10 times or until no air is emitted from the outlet ports. - When finished, cap the outlet ports and install the master-cylinder. Syringe Fill the syringe (one especially designed for brake bleeding) with clean brake fluid. - Insert the end of the syringe into one of the outlet ports on the master-cylinder. - Slowly compress the syringe and back flush the brake fluid through the master-cylinder. - A combination of air and brake fluid will be emitted from the inlet port in the fluid reservoir. - Repeat this procedure until only brake fluid is emitted into the reservoir. Cap the outlet ports and install the master-cylinder. Page 2721 Compression Check: Testing and Inspection COMPRESSION CHECK - Disconnect the primary terminal from the ignition coil. - Remove all spark plugs. - Block the throttle plate wide open. - Make sure the battery is fully charged. Starting with the compression gauge at zero, crank the engine through four compression strokes (four "puffs"). - Make the compression check at each cylinder and record each reading. - If some cylinders have low compression, inject 15 ml (one table spoon, or 3 squirts from a pump type oil can) of engine oil into the combustion chamber through the spark plug hole. - Minimum compression recorded in any one cylinder should not be less than 70 percent of the highest cylinder, and no cylinder should read less than 690 kPa (100 psi). Normal Compression: Compression builds up quickly and evenly to specified compression on each cylinder. Piston Rings Leaking: Compression low on first stroke, tends to build up on following strokes, but does not reach normal. Improves considerably with addition of oil. Valves Leaking: Low on first stroke. Does not tend to build up on following strokes. Does not improve much with addition of oil. Head Gasket Leakage: If two adjacent cylinder have lower than normal compression, and injecting oil into cylinders does not increase the compression, the cause may be a head gasket leak between the cylinders. Page 6440 Vehicle Limited Warranty, dealers are instructed to proceed as follows: Important: On vehicles equipped with A/C systems NOT produced by GM (i.e., rear A/C systems in van conversions), consult the manufacturer of that A/C system for retrofit guidelines. ^ Offer the customer the option of repairing and recharging the system with R12, or retrofitting after repair and recharging with R-134a at no additional charge. ^ Provide the owner with, and review the information contained in, the "Converting Your Auto Air Conditioning System to Use the New Refrigerant" brochure. (Brochure, Form GM-0011, can be ordered free of charge from GM Fulfillment HQ, Phone 1-800-269-5100). ^ Record the customer's choice on the repair order and, as with all properly completed repair orders, ask the customer to sign on the appropriate line acknowledging the repairs requested. ^ Under no circumstances should the retrofit to R-134a be performed unless the customer has had the option explained prior to repair. Once the vehicle has been retrofitted to R-134a, a significant expenditure would be incurred to go back to R-12, in the event the customer has changed his/her mind. THIS OFFER APPLIES ONLY TO VEHICLES REQUIRING A/C REFRIGERANT SYSTEM REPAIRS UNDER THE TERMS OF THE NEW VEHICLE LIMITED WARRANTY. It is not a special policy, and any existing deductibles still apply. This is simply an option being offered to the customer during the warranty period at this time. GM reserves the right to terminate this offer at any time. If the R-12 refrigerant system does not require discharging for a warranty repair, but the customer requests a retrofit to R-134a, the retrofit WOULD BE PERFORMED AT THE CUSTOMER'S EXPENSE, EVEN DURING THE WARRANTY PERIOD. 2. Customer Paid Retrofitting Costs If the customer requests a retrofit to R-134a, for a specific vehicle whose retrofit parts and procedures have been released in this bulletin, the customer would be expected to pay the costs to retrofit under the following conditions: ^ The vehicle is no longer covered by the terms of the New Vehicle Limited Warranty. ^ The vehicle is covered by warranty, but the repair covered under the warranty does not require evacuating and recharging the refrigerant system. 3. Labor Time Information For Vehicles Repaired Under Warranty: Use existing labor operations for correcting the original condition. The quantity of R-134a used should be charged to the normal labor operation (not D4500), just as if it were R-12. Use D4500, 0.3 HR., to charge for parts and labor, for all of the following items: ^ Additional time for recovery of R-12 to meet SAE standards; ^ Install high and low side service port converter fittings; ^ Add PAG or V5 retrofit oil; ^ Complete label information and install. Add 0.2 hours to D4500 for installation of the HPCOS. Use T5321, 0.3 HR., for the Pontiac Bonneville hood seal installation. ANY PARTS OR LABOR TIME OTHER THAN THOSE LISTED ABOVE SHOULD BE CHARGED TO THE REGULAR LABOR OPERATION CORRESPONDING TO THE ORIGINAL CONDITION THAT 1S BEING REPAIRED. Page 5278 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 87 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 5588 Use applicable labor time guide for labor hours. Page 508 Door Switch: Locations RH Rear Door Jamb Switch In RH B-Pillar Page 3019 Upshift Indicator: Testing and Inspection Manual Transmission Shift Light Circuit Check Page 3660 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 6683 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 146 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Locations Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Oxygen Sensors - Silica Contamination Oxygen Sensor: Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Tailgate - Latch Rattle, Revised Striker & Latch Trunk / Liftgate Striker: Technical Service Bulletins Tailgate - Latch Rattle, Revised Striker & Latch Number: 92-153-10 Section: 10 Date: APRIL 1992 Corporate Bulletin No.: 161514 ASE No.: B1 Subject: END GATE LATCH RATTLE Model and Year: 1983-92 S/T TRUCKS Owners of some 1983-1992 S/T 2 and 4 door utility vehicles may comment that their end gate latch rattles. One possible cause of this condition is the end gate latch fork bolts contacting the striker assembly (metal-tometal) causing a rattle. To correct this condition, it is necessary to install a new striker assembly that has a urethane sleeve over the striker post. The urethane sleeve preventsmetal-to-metal contact and may eliminate the rattle. SERVICE PROCEDURE: Steering/Suspension - Wheel Alignment Specifications Alignment: Technical Service Bulletins Steering/Suspension - Wheel Alignment Specifications WARRANTY ADMINISTRATION Bulletin No.: 05-03-07-009C Date: December 09, 2010 Subject: Wheel Alignment Specifications, Requirements and Recommendations for GM Vehicles Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks Supercede: This bulletin is being extensively revised to provide technicians and warranty administrators with an all inclusive guide for wheel alignments. PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. Please discard Corporate Bulletin Number 05-03-07-009B (Section 03 - Suspension). Purpose The purpose of this bulletin is to provide retail, wholesale and fleet personnel with General Motors' warranty service requirements and recommendations for customer concerns related to wheel alignment. For your convenience, this bulletin updates and centralizes all of GM's Standard Wheel Alignment Service Procedures, Policy Guidelines and bulletins on wheel alignment warranty service. Important PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. The following five (5) key steps are a summary of this bulletin and are REQUIRED in completing a successful wheel alignment service. 1. Verify the vehicle is in an Original Equipment condition for curb weight, tires, wheels, suspension and steering configurations. Vehicles modified in any of these areas are not covered for wheel alignment warranty. 2. Review the customer concern relative to "Normal Operation" definitions. 3. Verify that vehicle is within the "Mileage Policy" range. 4. Document wheel alignment warranty claims appropriately for labor operations E2000 and E2020. The following information must be documented or attached to the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 5. Use the proper wheel alignment equipment (preferred with print-out capability), process and the appropriate calibration maintenance schedules. Important If it is determined that a wheel alignment is necessary under warranty, use the proper labor code for the repair. E2000 for Steering Wheel Angle and/or Front Toe set or E2020 for Wheel Alignment Check/Adjust includes Caster, Camber and Toe set (Wheel alignment labor time for other component repairs is to be charged to the component that causes a wheel alignment operation.). The following flowchart is to help summarize the information detailed in this bulletin and should be used whenever a wheel alignment is performed. Service and Repair Fuel Pressure Release: Service and Repair Fuel Supply System CMFI FUEL PRESSURE RELEASE PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure - Connect fuel pressure gauge to fuel pressure connection tap. Wrap a shop towel around fitting while connecting gauge to avoid spillage. - Install bleed hose into an approved container and open valve to bleed system pressure. Fuel connections are now safe for servicing. - Drain any fuel remaining in gauge into an approved container. Page 2390 Water Pump: Service and Repair Fig. 19 Water Pump Bolt Location 1. Drain cooling system. 2. Remove serpentine drive belt, then the upper fan shroud. 3. Remove fan, fan clutch assembly and water pump pulley, Fig. 19. 4. Remove hoses from pump. 5. Remove water pump attaching bolts, then pump. 6. Reverse procedure to install. Torque bolts to specification. Page 5647 Steering Gear: Description and Operation Saginaw Integral Power Steering Gear Fig. 1 Exploded view of power steering gear The power steering gear has a recirculating ball system which acts as a rolling thread between the worm shaft and the rack piston, Fig. 1. The worm shaft is supported by a thrust bearing preload and two conical thrust races at the lower end, and a bearing assembly in the adjuster plug at the upper end. The control valve in the steering gear directs the power steering fluid to either side of the rack piston. The rack piston converts the hydraulic pressure into a mechanical force. If the steering system loses hydraulic pressure, the vehicle can be controlled manually. When the worm shaft is turned right, the rack piston moves up in the gear while turning left moves the rack piston down in the gear. The rack piston teeth mesh with the pitman shaft sector. Turning the worm shaft turns the pitman shaft, which turns the wheels through the steering linkage. Page 4138 For vehicles repaired under warranty use: Page 4316 7. Rotate cage several revolutions to assure normal bearing contact. 8. Press flange or yoke against forward bearing and install washer and pinion shaft nut. 9. Place pinion and cage assembly over carrier studs, hold flange with suitable tool, and torque pinion shaft nut to 350 ft. lbs. 10. Check pinion bearing preload torque. If rotating torque is not within 5 to 15 pound inches, disassemble, adjust spacer, reassemble, and recheck preload torque. Use thinner spacer to increase or thicker spacer to decrease preload. 11. Hold flange with suitable tool and remove pinion shaft nut and flange. 12. Lubricate pinion shaft oil seal and cover outer edge of seal body with non-hardening sealing compound, then press seal against cover shoulder with suitable tool. 13. Install new gasket and bearing cover. 14. Press flange against forward bearing and install washer and pinion shaft nut, torquing nut to 350 ft. lbs. Page 7838 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 5477 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). A/C - Retrofitting R-12 Vehicles to R-134A Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Page 7574 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Locations Brake Vacuum Release Valve: Locations Cruise Control Components, Near Steering Column. Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes A/T - Torque Converter Replacement Information Torque Converter: All Technical Service Bulletins A/T - Torque Converter Replacement Information INFORMATION Bulletin No.: 01-07-30-010C Date: May 12, 2008 Subject: Automatic Transmission/Transaxle Torque Converter Replacement Models: 2009 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saturn Cars and Light Duty Trucks (Except VTi Equipped Vehicles (RPO M16 and M75) 2009 and Prior Saab 9-7X with ALL Automatic Transmissions and Transaxles Supercede: This bulletin is being revised to add the 2007-2009 model years. Please discard Corporate Bulletin Number 01-07-30-010B (Section 07 - Transmission/Transaxle). The purpose of this bulletin is to help technicians determine when a torque converter should be replaced. Below is a list of general guidelines to follow. The converter should NOT be replaced if the following apply: ^ DTC P0742 - TCC stuck on is set. This code is almost always the result of a controls condition (i.e. stuck TCC solenoid/valve). Experience has shown that this code rarely indicates a mechanical concern within the torque converter. ^ The fluid has an odor or is discolored but no evidence of metal contamination. ^ Fine metal particles (traces of metal flakes/gray color to fluid ) are found in the converter. This is not harmful to the torque converter. ^ The vehicle has been exposed to high mileage. ^ A small amount of wear appears on the hub where the oil pump drive gear mates to the converter (RWD only). A certain amount of such wear is normal for both the hub and oil pump gear. Neither the converter nor the front pump assembly should be replaced. The torque converter should be replaced under any of the following conditions: ^ The vehicle has TCC shudder and/or no TCC apply. First complete all electrical and hydraulic diagnosis and check for proper engine operation. The converter clutch may be damaged. Also the converter bushing and/or internal 0-ring may be damaged. ^ Evidence of damage to the oil pump assembly pump shaft turbine shaft drive sprocket support and bearing or metal chips/debris in the converter. ^ Metal chips/debris are found in the converter or when flushing the cooler and the cooler lines. ^ External leaks in the hub weld area lug weld or closure weld. ^ Converter pilot is broken damaged or fits poorly into the crankshaft. ^ The converter hub is scored or damaged. ^ The transmission oil is contaminated with engine coolant engine oil or water. ^ If excessive end play is found after measuring the converter for proper end play (refer to Service Manual). ^ If metal chips/debris are found in the fluid filter or on the magnet and no internal parts in the unit are worn or damaged. This indicates that the material came from the converter. ^ The converter has an unbalanced condition that results in a vibration that cannot be corrected by following Converter Vibration Procedures. ^ Blue converter or dark circular ring between lugs. This condition will also require a complete cleaning of the cooler and a check for adequate flow Page 6188 Bearing Staked In Place The stake metal should not contact the outer face of the bearing to prevent the possibility of distorting the outer race. Stake three (3) places 120° apart as shown in the illustration. Installing Pulley Rotor And Bearing Assembly 5. With the compressor mounted to the J 34992 holding fixture, position the rotor and bearing assembly on the front head. 6. Position the J 33017 pulley rotor and bearing installer and J 33023-A puller pilot directly over the inner race of the bearing. 7. Position puller crossbar J 8433-1 on the puller pilot J 33023-A and assemble the two J 34992-2 through bolts and washers through the puller bar slots and thread them into the J 34992 holding fixture. The thread of the through bolts should engage the full thickness of the holding fixture. 8. Tighten the center screw in the J 8433-1 puller crossbar to force the pulley rotor and bearing assembly onto the compressor front head. Should the J 33017 pulley rotor and bearing installer slip off direct in-line contact with the inner face of the bearing, loosen the J 8433-3 center forcing screw and realign the installer and pilot so that the J 33017 installer will properly clear the front head. 9. Install rotor and bearing assembly retainer ring, using snap ring pliers J 6083. 10. Reinstall clutch plate and hub assembly as described previously. Page 5739 Page 7659 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Locations Timing Connector Page 5169 Fuse Block: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Headlight Dimmer Switch Steering Column Page 6386 Adapter, High Side - 91172093 0-Rings: Compressor - Small (6) - 91172095 Large - 96068915 Receiver/dryer (2) - 96068488 Suction hose - 96068490 Discharge hose - 96068489 Suction hose - 91172091 Discharge hose - 91172085 1985-89 Spectrum and 1990-93 Storm (R) 1. Using the Service Manual, remove the following components in the order given: a. Condenser (Storm) or radiator grille (Spectrum) (to be reinstalled). b. Triple switch (Storm) or dual pressure switch (Spectrum) (to be reinstalled). c. Receiver/dryer. d. Evaporator to compressor (suction) pipe. e. Check valve from high side service valve (discard). f. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High side adapter fitting (see Step 3 of the retrofit procedure for detailed installation instructions). Low Side - Part of suction hose c. Evaporator to compressor (suction) pipe, and new 0-rings. d. Receiver/dryer and 0-rings. e. Triple switch or dual switch, and new 0-ring. f. Condenser or radiator grille. R-134a amount: 91 - 500 grams (1.10 lb) 92-93 - 600 grams (1.32 lb) PAG oil amount: 150 cc (4.50 oz) Parts Required: Receiver/dryer: 85-89 - 97104795 90-91 - 97104797 92-93 - 97104798 Adapter, High Side: Page 4047 through the cooler. ^ Converter bearing noise determined by noise from the bell housing area in Drive or Reverse at idle. The noise is gone in Neutral and Park. ^ If silicon from the viscous clutch is found in the lower pan (4T80-E ONLY). Disclaimer Page 4250 Fig. 2 Exploded View Of Eaton Locking Differential 1. Remove guide clips and clutch discs from gear keeping components in order. 2. Clean and inspect components, and replace as needed. If side gear shim is defective, it must be replaced with one of equal thickness. If side gear is replaced, and/or if side gear shim thickness cannot be determined, perform SIDE GEAR SHIM SELECTION procedure. 3. Install eared and splined clutch discs on side gear, starting with eared disc as shown in Fig. 2. If components are reused, they must be installed in original position. 4. Install selected shim on side gear. Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Page 704 EGR AND EVRV SOLENOID 4.3 L Page 6560 Antenna location is a major factor in these effects. b. The antenna should be a permanent-mount type, located in the center of the roof or center of the rear deck lid. If a magnet-mount antenna is used, care should be taken to mount the antenna in the same location as a permanent-mount type. If a disguise-mount antenna is used, great care should be taken to shield (using copper tape, etc.) any tuning network from vehicle electronics and wiring, or mount the tuning network in an area completely clear (6 inches or 15 cm away) of vehicle electronics and wiring. c. Standard metal mount antennas may be mounted on a vehicle with non-metallic body panels by two methods: 1. Mount the antenna near a metal frame section and bond the antenna mount to the frame with a short metal strap, which will provide the ground plane connection. 2. Some antenna manufacturers may offer "Ground Plane Kits" that consist of self adhesive metal foil that may be attached to the body panel to provide a ground plane connection. d. Glass Mount Antennas Glass mounted antennas should be kept as high as possible in the center of the rear window or windshield, between rear window defrost "grid lines", if present. Some vehicles use glass that contains a thin metallic layer for defrosting, or to control solar gain. GLASS MOUNT ANTENNAS WILL NOT FUNCTION WHEN MOUNTED ON THIS TYPE OF GLASS. 3. Antenna Cable Routing a. Always use high quality coax cable (95% shield coverage minimum), located away (at least 6 inches or 15 cm) from ECM's, PCM's and other electronic modules. b. Care should be taken to maintain as great a distance as possible between any vehicle wiring and coax cable. 4. Antenna Tuning It is important that the antenna be tuned properly and that reflected power be kept to less than 10% (VSWR less than 2:1) at all operating frequencies. Important: High VSWR has been shown to contribute/cause interference problems with vehicle systems. 5. Radio Wiring and Power Lead Connection Locations a. Methods to connect radio power on General Motors vehicles is dependent on the vehicle model (See Figure 1 - One Piece Transceiver Installation or Figure 2 - Trunk Mount Transceiver Installation as needed). Do not connect the negative power lead to any under-dash termination point. One of the following four methods is suggested: 1. Connect the positive and negative power leads directly to the battery terminals. GM approved methods of connecting auxiliary wiring include the adapter package illustrated in Figure 4 - Power Cable Battery Connections. Important: It is recommended that a fuse be placed in the transceiver negative power lead. This is to prevent possible transceiver damage in the event the battery to engine block ground lead is inadvertently disconnected. 2. Connect the positive lead to the auxiliary power terminal (usually identified by a red plastic cover in the underhood area). Connect the negative lead directly to the negative battery terminal. Important: See above important statement regarding fusing the negative power lead. 3. Connect the positive lead to the auxiliary power terminal (usually identified by a red plastic cover in the underhood area). Locations Brake Fluid Level Sensor/Switch: Locations At Brake Fluid Reservoir Page 2857 Quad Driver: Testing and Inspection Little or no quad driver testing was supplied by the manufacturer. The engine module decides when to turn each switch of the driver "ON". Even though some models will set codes, in the end, if you want to check the driver itself, you'll need: 1. To use a scantool to command the suspected driver switch to energize (ground) the circuit, while checking with a test light, 2. To operate the vehicle in a way that should cause the suspected portion of the driver to switch "ON". On the up side, since the early 90's, most driver load circuits utilized circuit breakers. This protected most drivers and engine models from burning up when the circuit was overloaded. Page 3109 Exhaust Gas Recircula- 3522442 tion Valve Base Gasket Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation: J6270 - Valve, EGR-Replace Labor Time: Use published labor operation time. ADD: Inspect and Repair Cowl (M/L Van ONLY)- 0.1 hour Page 425 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Page 2945 Rear Of Engine Paint - Identification/Repair of Colorcoat Delamination Paint: All Technical Service Bulletins Paint - Identification/Repair of Colorcoat Delamination BULLETIN NUMBER: 92-1O-134A SECTION: 10 Body NUMBER: 4 CORPORATE REFERENCE NUMBER: 231054R DATE: July 1993 SUBJECT: SERVICE PROCEDURES FOR IDENTIFICATION AND REPAIR OF PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER MODELS: 1988-92 TRUCKS THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 92-10-134 (CORP # 231054R), DATED OCTOBER 1992. IT IS BEING REVISED TO REMOVE THE COVER LETTER PORTION AND SUBJECT STATEMENT NOW INCLUDES NOTE FOR TRUCKS AND REVISES THE MONOCOAT MATERIAL ALLOWANCES ON "G", "S/T" AND SOME "R/V" MODELS. THE ALLOWANCE FOR "ADD FOR TWO-TONE" ON G AND S/T TRUCKS HAS BEEN CHANGED. ALL COPIES OF 92-10-134 SHOULD BE DISCARDED. The revisions are the result of changes to the MONOCOAT (ENAMEL) material allowance charts published in June, 1993. Six (6) of the "G" model revisions use Basecoat/Clearcoat material allowance codes. THESE ARE TO BE USED AS DOLLAR REFERENCES ONLY, AND ARE MARKED WITH A # INDICATOR. Continue to repair these vehicles with monocoat materials. DO NOT repair these vehicles with Basecoat/Clearcoat products. Use the latest (June, 1993) material allowance charts when submitting claims. SUBJECT: Service procedures for the repair of paint colorcoat delamination from elpo primer (repaint entire body above the body side moldings, except trucks as noted). APPLICATION: 1988-1992 LIGHT DUTY TRUCKS (C/K, R/V, S/T, M/L AND G) This bulletin cancels and supersedes service procedures and time allowances on all previous bulletins regarding paint DELAMINATION. Due to the use of new procedures, add times for optional equipment, and designating specific hardware items for removal, the published labor times will not be the same as previously published. CONDITION This bulletin is being issued to assure that the correct procedure is followed to repair a condition known as DELAMINATION. Some of the above listed passenger cars, light duty trucks, and vans may have DELAMINATION (peeling) of the paint color-coat from the ELPO primer depending upon variable factors including prolonged exposure to sunlight and humidity. Blues, Grays, Silvers and Black Metallics are the colors that have the highest potential for this condition. On rare occasions, other colors may be involved. Important DELAMINATION is different than other paint conditions and/or damage. A proper problem identification is necessary, and the service procedure that follows is specific to the proper repair of DELAMINATION and must be followed. The information in this bulletin covers Paint DELAMINATION of the colorcoat from the ELPO primer ONLY. It does not address any other paint conditions. Procedures for the repair of other paint conditions (stone chips, scratches, environmental damage, clearcoat peeling, runs, dirt, fading, etc.) will not effectively repair DELAMINATION and customer dissatisfaction will result. CAUSE This condition may occur on vehicles produced in plants where the paint process does not call for application of a primer surfacer. Under certain conditions, ultraviolet light can penetrate the colorcoat, sometimes causing a reaction and separation of portions of the colorcoat from the ELPO (electrocoat) primer. PROBLEM IDENTIFICATION: Page 7743 Cigarette Lighter: Electrical Diagrams Refer to LIGHTING SYSTEMS/INTERIOR LAMPS for Cigarette Lighter wiring circuit. Heater Core Replacement Heater Core: Service and Repair Heater Core Replacement Remove or Disconnect Page 1872 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 7365 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 4690 NOTE: A drum which is out of round will cause a pedal pulsation to be felt upon braking. - The measurement should also be repeated at various depths of the drum to check for a bellmouth condition. If the measurements differ by more than .010 inches the drum should be resurfaced. NOTE: 1 inch = 25.4mm, so if your micrometer measures in inches and the specified thickness on the disc is in millimeters, convert millimeters to inches by dividing the specified number of millimeters by 25.4. Example: Specification on disc is 17.8 mm. Dividing 17.8mm by 25.4mm/in = 17.8/25.4 = 0.70 inches. Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Page 7271 Cruise Control Servo: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Tires/Wheels - Tire Puncture Repair Procedures Tires: All Technical Service Bulletins Tires/Wheels - Tire Puncture Repair Procedures INFORMATION Bulletin No.: 04-03-10-001F Date: April 27, 2010 Subject: Tire Puncture Repair Procedures For All Cars and Light Duty Trucks Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-001E (Section 03 - Suspension). This bulletin covers puncture repair procedures for passenger car and light duty truck radial tires in the tread area only. The tire manufacturer must be contacted for its individual repair policy and whether or not the speed rating is retained after repair. Caution - Tire changing can be dangerous and should be done by trained professionals using proper tools and procedures. Always read and understand any manufacturer's warnings contained in their customers literature or molded into the tire sidewall. - Serious eye and ear injury may result from not wearing adequate eye and ear protection while repairing tires. - NEVER inflate beyond 275 kPa (40 pounds) pressure to seat beads. Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. - NEVER stand, lean or reach over the assembly during inflation. Repairable area on a radial tire. Important - NEVER repair tires worn to the tread indicators 1.59 mm (2/32") remaining depth). - NEVER repair tires with a tread puncture larger than 6.35 mm (1/4"). - NEVER substitute an inner tube for a permissible or non-permissible repair. - NEVER perform an outside-in tire repair (plug only, on the wheel). - Every tire must be removed from the wheel for proper inspection and repair. - Regardless of the type of repair used, the repair must seal the inner liner and fill the injury. - Consult with repair material supplier/manufacturer for repair unit application procedures and repair tools/repair material recommendations. Three basic steps for tire puncture repair: 1. Remove the tire from the wheel for inspection and repair. Page 8102 Rear Lamps Harness Page 4729 1. Begin by opening the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (figure 2). 2. Attach the valve pressure bleeding tool J39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (figure 3). Tighten tool J39177 only finger tight. NOTE: It is not necessary to attach bleeding tool J39177 to the combination valve when using the manual bleed procedure. 3. Bleed each wheel in the following sequence: - Right rear - Left rear - Right front - Left front NOTE: Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. NOTE: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 4. Slowly apply the brake pedal one time and hold. 5. Loosen the bleeder valve to purge the air from the wheel cylinder/caliper. 6. Tighten the bleeder valve and slowly release the pedal. 7. Wait 15 seconds. 8. Be sure to check the master cylinder fluid level after 4-5 strokes to avoid running dry. 9. Repeat steps 4 through 8, until all air is purged from the wheel cylinder/caliper. NOTE: It may be necessary to repeat this sequence as many as 15 to 20 times per wheel. 10. Fill the master cylinder to the proper level and replace lid. 11. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs.in.). 12. Remove the valve pressure bleeding tools J39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 13. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. IMPORTANT: DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 14. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. IMPORTANT: DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 15. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs.in.). 16. Fill the master cylinder to the proper level with brake fluid. 17. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. IMPORTANT: MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 18. Repeat the entire brake bleed procedure if necessary. Warranty Information LABOR OP. MODEL H0700 S/T H0700 M/L H0700 C/K H0700 G Use applicable labor time guide for labor hours. Page 6146 Removing Pulley Rotor & Bearing Assembly Retaining Ring 2. Remove rotor and bearing assembly retaining ring, using snap ring pliers J 6083. Installing Pulley Rotor/Bearing Puller Guide Page 2315 Heater Hose: Service and Repair Engine Heater Hose Routing (w/ Air Conditioning) The heater inlet hose is routed from the intake manifold to the inlet pipe of the heater core. The heater outlet hose is routed from the outlet pipe of the heater core to the inlet fitting of the coolant pump. Hoses are attached at each end with screw-type clamps. REMOVE OR DISCONNECT 1. Engine coolant. - Drain enough coolant into a clean container to lower the coolant level below the level of the lowest heater hose fitting. 2. Inlet and outlet hoses (72 and 70) at fittings. - Loosen the clamp screws enough to slide the clamps away from the fittings on the inlet and outlet hoses (72 and 70). - Remove the hose end by twisting and pulling. NOTICE: The heater core can be damaged if too much force Is applied on the core tubes During removal If the heater hose will not come off easily, cut off the hose forward of the heater core tube. Cut the hose remaining on the core tube lengthwise to remove it. 3. Hose Support clamps, brackets and/or retainers, as necessary. 4. Heater hose(s) (72 and 70) and clamps. INSTALL OR CONNECT 1. Healer hose(s) (72 and 70) and clamps. 2. Hose support clamps, brackets and/or retainers, if removed. 3. Inlet and outlet hoses (72 and 70) to fittings. Oil Pressure Gauge - Incorrect or Erratic Readings Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Incorrect or Erratic Readings Number: 93-57-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268304 ASE No.: A1, A8 Subject: INCORRECT OR ERRATIC OIL PRESSURE READINGS Model and Year: 1990-93 ALL LIGHT DUTY TRUCKS Owners of some 1990 through 1993 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. Service Procedure: Check for normal causes of high oil pressure gauge readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure below. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. connect the negative battery cable. Parts Information: Page 8312 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 1338 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 1220 Technical Service Bulletin # 631209 Date: 960501 A/C - R12 or R134a Service Recommendations File In Section: 1 - HVAC Bulletin No.: 63-12-09 Date: May, 1996 INFORMATION Subject: Service Issues for Vehicles with R12 or R134a Air Conditioning Systems Models: 1988-96 Passenger Cars and Trucks R12 Service Recommendations As you know, production of R12 refrigerant ceased on December 31, 1995. Although R12 will no longer be manufactured, there is a reserve supply of R12 available. This reserve, along with strict A/C repair service adherence to proper refrigerant recycling procedures, should assure continued availability to meet consumers' needs. R12 can and should continue to be used to service vehicles built with R12 A/C systems as long as it is available. If R12 is no longer available or affordable, a system retrofit utilizing R134a is recommended. R134a IS THE ONLY SUBSTITUTE REFRIGERANT RECOMMENDED BY GM FOR USE IN GM VEHICLE A/C SYSTEMS, AND THEN ONLY AFTER FOLLOWING THE PROPER RETROFIT PROCEDURES FOR THE SPECIFIC MODEL. All new vehicle manufacturers have chosen R134a for retrofit. One of the key reasons is to protect both the service industry and consumers from the high costs that would result from purchasing equipment necessary to service multiple refrigerants. This position also reduces the threat of recycled refrigerant contamination. GM currently offers a simple, low cost R12 to R134a retrofit on many of its late model, front wheel drive passenger cars. Dealers should discuss this capability with owners of these specific models, listed in Retrofit Corporate Bulletin # 43-12-07D, whenever a repair to the A/C refrigerant system is required. Early retrofit of these specific models will aid in prolonging availability of the R12 supply and provide dealer service technicians the opportunity to become more familiar with the proper procedures for performing a retrofit. Remember - R12 and R134a refrigerant are not interchangeable! They cannot be mixed together. In fact, despite the claims of some refrigerant manufacturers, no proposed R12 refrigerant substitute can be added to, mixed with or used to "top off" an R12 system. Under provisions of law covering the service of refrigerants, mixing dissimilar refrigerant products during service is prohibited. To Summarize GM R12 Service Policy 1. Service R12 vehicles with good quality new or recycled R12 as long as it is available. 2. Purchase R12 from a reliable supplier. GMSPO has a supply of high quality R12 available. Dealers are requested to use only R12 supplied by GMSPO for warranty repairs. This high quality refrigerant will insure system performance and avoid the possibility of introducing contaminated material into the customer's A/C system. 3. Carefully test recovered R12 using the PureGuard monitor. On recovery equipment not protected by the PureGuard, always test the recovery cylinder prior to recharging a vehicle A/C system. 4. Discuss the R12 to R134a retrofit option with owners of GM vehicles listed in Retrofit Corporate Bulletin # 43-12-07D. Provide owner with a copy of the pamphlet "Converting Your Auto Air Conditioning System to Use the New Refrigerant". 5. Become familiar with retrofit procedures and exercise care in the handling of dissimilar refrigerants to prevent contamination. R134A Service Recommendations When servicing a previously retrofitted vehicle, there is concern that if all of the R12 is not completely removed prior to the retrofit procedure, it could contaminate your R134a equipment and recovery tank when a subsequent A/C repair is performed. Although the number of retrofits being performed today is minimal, the volume will increase as R12 prices rise. GM Service Technology Group is in the process of field testing a new R134a refrigerant purity tester similar to the PureGuard R12 refrigerant tester you now use. This new tool will mount to your ACR4 R134a Recovery Recycle and Recharge cart and sample all R134a refrigerant prior to recovery. It is expected that testing of this tool will be completed this year. This new tool, the Pureguard 2, will also test vehicles and your recycle tank for air contamination, which is threatening A/C system performance. High levels of air have been found in the recovery tanks on a number of R12 and R134a recovery carts. Air contamination is caused by improper recovery Page 5789 1. Center the repair unit over the injury as a reference and outline an area larger than the unit so that buffing will not remove the crayon marks. 2. Remove the repair unit. 3. DO NOT overlap previous or multiple repair units. 4. Consult your repair material supplier for proper repair unit selection. Buffing 1. To prevent contamination and preserve the outline, buff within the marked area thoroughly and evenly with a low speed buffing tool using a fine wire brush or gritted rasp. 2. Buff to a smooth velvet surface (RMA #1 or #2 buffed texture). 3. Use caution not to gouge the inner liner or expose casing fabric. 4. Remove any buffing dust with a vacuum cleaner. 5. Consult your repair material supplier for a proper buffing tool. Cementing Apply chemical cement according to the repair material manufacturer's procedures. Repair Unit Application Page 8310 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 7131 - Customer induced cuts (knife cuts, cut by customer tools, etc.) - Paint stains (customer should have cleaned paint stains while paint was still wet) - Coffee stains and other removable dirt These should be cleaned as described in the Owner's Manual under Appearance Care. Also, refer to Corporate Bulletin Number 06-00-89-029A or later. - Evidence of chemicals used for cleaning, other than those specified in the Owner's Manual - Other chemical spills - Minor and normal leather wrinkles as a result of use - Other defects to the seat cover not detected during the pre-delivery inspection (PDI). Inform the customer that the above issues were not present when the vehicle was purchased and cannot be replaced under warranty. The covers, however, may be repaired or replaced at the customer's expense. The following conditions are not caused by the customer and should be covered by warranty: - Split seams Page 7350 Symbol Identification Page 8202 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 7438 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 7839 Use applicable labor time guide for labor hours. Page 979 For vehicles repaired under warranty for Noise use: Labor Operation: T7460 Labor Time: 0.2 hours Clean A/C pulley and inspect for proper alignment 0.2 hours Loosen and align P/S pump pulley (include R and R lower shroud) Note: T7460 is coded to base vehicle coverage in the warranty system. For vehicles repaired under warranty for replacing serpentine belt use: Labor Operation: J0667 Use applicable labor time guide for labor hours. Lighting - Headlamp Polycarbonate Lens Damage Prevention Headlamp Lens: Technical Service Bulletins Lighting - Headlamp Polycarbonate Lens Damage Prevention INFORMATION Bulletin No.: 02-08-42-001D Date: June 21, 2010 Subject: Headlamp Lens Overheating When Covered and Chemical Damage to Exterior Polycarbonate Headlamp Lenses Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and to revise the warning statements. Please discard Corporate Bulletin Number 02-08-42-001C (Section 08 - Body and Accessories). The bulletin is being issued to make dealers and customers aware of chemical damage that may be caused to exterior polycarbonate headlamp lenses. Most late model vehicles have these types of headlamp lenses. This material is used because of its temperature and high impact resistance. A variety of chemicals can cause crazing or cracking of the headlamp lens. Headlamp lenses are very sensitive. Care should be exercised to avoid contact with all exterior headlamp lenses when treating a vehicle with any type of chemical, such as those recommended for rail dust removal. Rubbing compound, grease tar and oil removers, tire cleaners, cleaner waxes and even car wash soaps in too high a concentration may also attribute to this condition. This could result in the need to replace the entire headlamp housing. Warning Use only lukewarm or cold water, a soft cloth and a car washing soap to clean exterior lamps and lenses. Also, crazing or deformations of the lens may occur if a shop mat or fender cover is draped over the fender and covers a portion or all of the headlamp assembly while the DRL or headlamps are on. This action restricts the amount of heat dissipated by the headlamps. Warning Care should be taken to not cover headlamps with shop mats or fender covers if the vehicle is being serviced with the headlamps or DRL illuminated. Covering an illuminated lamp can cause excessive heat build up and crazing/deformation of the lens may occur. The degradation of the lens can be unnoticeable at first and eventually become hairline cracks in the lens. In extreme cases, it could cause the lens to deform. This damage can also be caused by aftermarket shields that are often tinted in color. Once a heat buildup is generated by the headlamp, a degradation of the headlamp lens begins. This degradation of the lens can be unnoticeable at first and eventually manifest as spider cracks. In more extreme cases, it will begin to melt the lens of the headlamp. Notice Headlamps damaged by chemicals, improper cleaning, or overheating due to being covered are not covered under the new vehicle warranty. Disclaimer Specifications Refrigerant Oil: Specifications REFRIGERANT OIL TYPE - R-12 refrigerant oil, 525 viscosity. NOTE: If vehicle has been converted to R-134a use PAG (Polyalkaline Glycol) synthetic refrigerant oil (GM Part No. 12345923) or equivalent. Page 339 Figure 7 Figure 8 Figure 9 Figure 10 Fuel System - TOP TIER Detergent Gasoline (Canada) Fuel: All Technical Service Bulletins Fuel System - TOP TIER Detergent Gasoline (Canada) INFORMATION Bulletin No.: 05-06-04-022G Date: October 27, 2010 Subject: TOP TIER Detergent Gasoline Information and Available Brands (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - Canada ONLY Models: 2011 and Prior GM Passenger Cars and Trucks (Canada Only) Supercede: This bulletin is being revised to update the model years and include an additional gasoline brand as a TOP TIER source. Please discard Corporate Bulletin Number 05-06-04-022F (Section 06 - Engine/Propulsion System). In the U.S., refer to the latest version of Corporate Bulletin Number 04-06-04-047I. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by the Canadian General Standards Board (CGSB). Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. Intake valve: 16,093 km (10,000 mi) with TOP TIER Detergent Gasoline Intake valve: 16,093 km (10,000 mi) with Minimum Additive recommended by the CGSB Top Tier Fuel Availability Chevron was the first to offer TOP TIER Detergent Gasoline in Canada. Shell became the first national gasoline retailer to offer TOP TIER Detergent Gasoline across Canada. Petro-Canada began offering TOP TIER Detergent Gasoline nationally as of October 1, 2006. Sunoco began offering TOP TIER Detergent Gasoline in March of 2007. Esso began offering TOP TIER Detergent Gasoline in May of 2010. Page 5269 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 8489 Turn Signal Switch: Service and Repair Fig. 6 Compressing Lock Plate 1. Disconnect battery ground cable. 2. Remove steering wheel as outlined under STEERING WHEEL & HORN SOUNDER. 3. Using a screwdriver, pry cover from lock plate. 4. Using lock plate compressing tool No. J-23653, compress lock plate and pry retaining ring from groove on shaft, Fig. 6. Slowly release lock plate compressing tool, remove tool and lock plate from shaft end. 5. Slide canceling cam and upper bearing preload spring from end of shaft. 6. Remove turn signal (multi-function) lever. 7. Remove hazard warning knob retaining screw, button, spring and knob. 8. Remove pivot arm. 9. Remove switch retaining screws and pull switch up from column, guiding wire harness through column. 10. Reverse procedure to install. Instrument Panel and Gauges - Revised Doesn't Light Test Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel and Gauges Revised Doesn't Light Test File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-05 Date: January, 1997 SERVICE MANUAL UPDATE Subject: Section 83C - Instrument Panel and Gauges Models: 1992 Chevrolet and GMC S/T Models This bulletin revises the diagnostic procedure "Cluster Display Does Not Light" for the Electronic Digital instrument Cluster as found on Page 8C-3 in 1992 Chevrolet Trucks S-10 Models, Service Manual ST 369-92. ^ Delete or cross-out the existing PROBLEM: Cluster Display Does Not Light. ^ Replace it with the revised PROBLEM: Page 5460 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 7525 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 7442 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 5033 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 358 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Locations Steering Column Page 4970 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 1589 Wheel Fastener: Specifications Wheel Fastener Tightening Sequence Lug Nut Torque Patterns IMPORTANT Check all parts, including rims, lug studs, lug nuts, and mating surfaces of hubs and tire rims for rust, damage, or dirt. Clean mating surfaces with a wire brush to remove any foreign material. Replace any damaged parts as needed. Careless installation of tire/rim assemblies in a vehicle is a major cause of tire installation problems. Proper installation, including fastener torque, is essential to economical, safe and trouble free service. Use only the proper sizes and types of fasteners for safe and proper service. Tighten the fasteners a quarter turn at a time using the tightening sequence diagram as a guide. This is very important to prevent misalignment of the wheel. Continue tightening the fasteners in sequence until the fasteners are tightened to the proper torque (See WHEEL FASTENER TORQUE). CAUTION: Improper torque or tightening sequence can cause distortion, fatigue cracks, or alignment problems. After driving the vehicle for a short distance, recheck the wheel fastener torque. Parts will usually seat naturally, reducing the torque on the fasteners. Retorque all fasteners to the proper torque. Page 5390 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 5039 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 2068 Idle Speed: Adjustments NOTE: Before performing this check: - Verify no codes displayed. - Idle air control system has been checked. - Ignition timing is correct. CONTROLLED IDLE SPEED CHECK - Set parking brake and block drive wheels. - Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. - START engine and bring it to normal operating temperature. - Check for correct state of PARK/NEUTRAL switch on SCAN tool. - Check specifications chart for controlled idle speed and IAC valve pintle position (counts). - If within specifications, the idle speed is being correctly controlled by the control module. - If not within specifications, refer to DIAGNOSIS BY SYMPTOM. See: Powertrain Management/Fuel Delivery and Air Induction/Testing and Inspection MINIMUM IDLE AIR RATE CHECK Minimum Idle Air Rate is not adjustable on this engine. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2] Auto D 550 5-40 CL [1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop). Page 2662 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 648 Oxygen Sensor: Technical Service Bulletins Engine Controls - Heated Oxygen Sensor Diagnosis Group Ref.: Engine Fuel & Emission Bulletin No.: 366501 Date: November, 1993 INFORMATION SUBJECT: HEATED OXYGEN SENSOR DIAGNOSIS MODELS: 1992-93 CHEVROLET & GMC LIGHT DUTY TRUCKS WITH 4.3L (LB4/L35), 5.0L (L03) AND 5.7L (L05) ENGINES 1992-93 OLDSMOBILE BRAVADA Some heated oxygen sensors are being replaced in error due to low reference voltage. REFERENCING SERVICE MANUAL Before diagnosing any heated oxygen sensor, be sure to follow the appropriate service manual diagnostics. The fault tree selected is dependent upon which control module system is on the vehicle. DIAGNOSTIC INFORMATION The electronic control module (ECM) normally applies a reference voltage of approximately 450mv to the oxygen sensor. When the ignition is turned "on", the heating element inside the oxygen sensor will immediately start heating the sensor element. The oxygen sensor will become fully functional in 15 to 90 seconds. Because the engine is not running, the gases around the oxygen sensor in the exhaust stream will be mostly ambient air. The high amount of oxygen in the exhaust stream will be interpreted as a lean exhaust and the 450mv reference voltage from the ECM will be pulled low. The oxygen sensor voltage should drop from 450mv to less than 100mv within 90 seconds. Therefore, the oxygen sensor is performing normally. LOW REFERENCE VOLTAGE (This test must be completed within 10 seconds after key up.) If your Tech 1 initial reference voltage is low (less than 300mv), you may have a shorted oxygen sensor. Turn the ignition "off"; allow the sensor to cool for ten minutes and retest. If the voltage is still low, disconnect the oxygen sensor and see if your Tech I now indicates approximately 450mv reference voltage. If so, change the oxygen sensor. HIGH REFERENCE VOLTAGE If your Tech 1 initial reference voltage is high (greater than 600mv), you may have a sensor signal that is shorted to heater voltage. This may cause a code 45. Allow sensor to cool ten minutes and retest. If voltage still remains high, disconnect oxygen sensor. If reference voltage still remains high, you may have a short to voltage in the engine harness or an ECM problem. If you disconnect the oxygen sensor and reference voltage returns to approximately 450mv, replace the internally shorted oxygen sensor. Page 7316 Symbol Identification Page 672 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 4983 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 1838 Oil Pan: Service and Repair OIL PAN REPLACEMENT Remove or Disconnect - Drain the oil. 1. Engine from the vehicle. 2. Oil pan bolts, nuts, and reinforcements. 3. Oil pan. 4. Gasket. Clean - Sealing surfaces on the oil pan and engine block. Inspect - Oil pan gasket. Replace if necessary. Install or Connect Page 6303 Control Assembly: Service and Repair Control Assembly Replacement Page 507 Door Switch: Locations RH Front Door Jamb Switch In RH A-Pillar Page 2150 Valve Clearance: Specifications Valve Arrangement All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E Page 5224 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 A/C Refrigerant - Contamination Refrigerant: Technical Service Bulletins A/C Refrigerant - Contamination File In Section: 1 - HVAC Bulletin No.: 43-12-23 Date: September, 1994 Subject: Contaminated A/C Refrigerant Models: 1994 and Prior Passenger Cars and Trucks with R12 Air Conditioning Systems Government regulations limit the production of R12 refrigerant, commonly referred to as Freon, during 1994/1995 and restrict manufacture of new R12 material effective January 1, 1996. As R12 prices rise and supplies are depleted, it is anticipated non-approved substitute refrigerants and/or poor quality R12 material sold as new or reprocessed may become more prevalent. The Mobile Air Conditioning Society (MACS) recently expressed concern over reports of the sale of R12 refrigerant containing as high as 15% contamination by R22, a refrigerant commonly used in stationary home systems but unsuitable for use in mobile units. GM dealers should be careful to protect against contaminating their existing supplies of R12 or the A/C systems in customers' vehicles they service by dealing with reputable suppliers. All R12 refrigerant purchased for warranty repairs should be purchased through GM SPO to ensure GM quality standards are met. The use of non-approved R12 refrigerant substitutes, some of which contain flammable materials, has also been reported by MACS. These products are available to "do-it-yourselfers" who, in many cases, believe they are harmless replacements for the small cans of R12 used so commonly in the past. Once added to the A/C system, the vehicle can no longer be serviced using R12 recovery/recycling equipment without: - Risking permanent damage to recovery/recycling equipment - Contaminating the previously recovered R12 material in the recovery tank - Spreading the contamination when the recovered material is used to charge other vehicles or - Possible loss of the recovered material if the contaminated level is high enough to activate the air purge system Contaminated refrigerant also impacts customer satisfaction through poor vehicle A/C performance and loss of A/C system compressor/component durability. System or component failure resulting from the use of refrigerant which does not meet GM specification is not covered by the "New Vehicle Warranty". Unfortunately, there is no simple method to identify if a "do-it-yourselfer" or repair shop has added to or recharged a system with a non-approved refrigerant. The inability to protect against the spread of contaminated refrigerant threatens the recycling program and the industry's desire to maximize use of the remaining R12 supply. Beginning in 1993, General Motors STG, Harrison Division, Research Labs and Kent-Moore worked in conjunction with suppliers of various technologies to develop a tester to identify contaminated refrigerant in vehicle A/C systems before recovery. During development of the technology, several dealer service manager focus group studies were conducted to identify design features to best suit dealership needs. The discussions and surveys clearly indicated the desire for a dedicated instrument, permanently mounted to the refrigerant recovery cart to ensure ALL vehicles are automatically tested prior to recovering refrigerant. Testing ALL refrigerant for contamination prior to recovery is the ONLY means to ensure customer satisfaction, protect recovery equipment and avoid unintentional venting of refrigerant by your dealership. General Motors has evaluated all available technology for this project and only the J 39851 R12 "Pureguard" meets General Motors' specifications. The J 39851 R12 Pureguard Refrigerant Monitor has been classified as an essential tool and will be shipped by Kent-Moore to your dealership beginning in September of 1994. The essential price of the R12 "Pureguard" is $561 (for Canadian dealers the price is $800 Canadian). If your dealership has multiple R12 recovery equipment, additional units may be ordered from Kent-Moore for $561 at 1-800-345-2233. Features of the R12 "Pureguard" include: - Universally mounts to R12 Recovery Equipment - Automatically interrupts power to the Recovery Equipment when contaminated refrigerant is identified - Fully automatic design does not require technician action, training or interpretation - LCD displays Pureguard functions Upper Ball Joint: Testing and Inspection Upper Fig. 19 Checking Upper Ball Joint. 4 X 2 Models BRAVADA, TYPHOON & 4 X 2 MODELS Before checking ball joints, wheel bearings must be properly adjusted. 1. Raise vehicle and position floor stands under right and left lower control arms near each lower ball joint. 2. Position dial indicator against wheel rim, Fig. 19. 3. Shake wheel, Fig. 19, and read gauge. Horizontal deflection should not exceed .125 inch. 4. If reading exceeds .125 inch, or if ball stud has been disconnected from knuckle assembly and any looseness is detected or stud is loose, replace ball joint. Fig. 21 Checking Ball Joints. 4 X 4 Models 4X4 MODELS EXCEPT BRAVADA & TYPHOON Refer to Fig. 21 for ball joint inspection procedure on 4 x 4 vehicles. Page 6675 Tape Player: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Page 1218 Important: All of the following parts are NOT NEEDED for a normal retrofit. Follow the bulletin procedures to determine which parts you need! Individual vehicle kits are not necessary, since most of the parts are generic and only a few parts are needed for most vehicles. GEO Parts are listed in "Platform Details." Parts are currently available from GMSPO. D. Warranty Information 1. Vehicle Still Within the Original New Vehicle Limited Warranty Period When GM models for the years listed in the bulletin require repairs to the refrigerant system and the vehicles are still covered under the New Page 394 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module A/T - Click or Whine in Third or Fourth Gear Clutch: All Technical Service Bulletins A/T - Click or Whine in Third or Fourth Gear Number: 93-228-7A Section: 7A Date: JUNE 1993 Corporate Bulletin No.: 277121R ASE No.: A2 Subject: CLICK/WHINE IN THIRD/FOURTH GEAR Model and Year: 1988-93 CAPRICE, CAMARO AND CORVETTE 1988-93 C/K, RN, S/T, M AND G TRUCKS 1990-93 L VAN THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-157-7A, DATED APRIL 1992. THE 1993 MODEL YEAR HAS BEEN ADDED, AS WELL AS A NOTE IN THE CORRECTION SECTION. ALSO THE SERVICE PARTS INFORMATION HAS BEEN CHANGED. ALL COPIES OF 92-157-7A SHOULD BE DISCARDED. CONDITION: Some 1988-93 vehicles with HYDRA-MATIC 4L60 or 4L60-E transmissions built before November 19, 1992 (Julian Date 324) may exhibit a clicking or whining noise in third and fourth gear. A customer may also describe it as a ticking or rattle noise. CAUSE: The clicking noise is caused by transmission fluid passing over the friction plates of the low and reverse clutch. The fluid causes them to vibrate when the low and reverse clutch is not applied (third and fourth gear). CORRECTION: Install five new fiber plates in the low and reverse clutch. The new plates have a non-groove configuration. NOTE: All HYDRA-MATIC 4L60 and 4L60-E transmissions built on or after November 19,1992 (Julian Date 324) have been assembled with the new low and reverse clutch fiber plates. SERVICE PARTS INFORMATION: Parts are expected to be available on 6/07/93. Locations Timing Connector Page 5068 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 8201 Figure 7 Figure 8 Figure 9 Figure 10 Service and Repair Fuel Pressure Release: Service and Repair Fuel Supply System CMFI FUEL PRESSURE RELEASE PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure - Connect fuel pressure gauge to fuel pressure connection tap. Wrap a shop towel around fitting while connecting gauge to avoid spillage. - Install bleed hose into an approved container and open valve to bleed system pressure. Fuel connections are now safe for servicing. - Drain any fuel remaining in gauge into an approved container. Page 8567 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Body - Stain/Film On Windshield Glass Perimeter Windshield: All Technical Service Bulletins Body - Stain/Film On Windshield Glass Perimeter TECHNICAL Bulletin No.: 09-08-48-006 Date: September 18, 2009 Subject: Clear Stain or Film on Inside Perimeter of Windshield Glass (Clean/Polish Glass) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Condition Some customers may comment on a clear stain or film on the inside of the windshield glass. This condition appears along the outer edges of the glass along the top, bottom or A-pillar areas. Normal glass cleaning procedures will not remove the stain. Cause The assembly plant uses a clear sealer/primer on the outer edge of the windshield glass to improve adhesion to the urethane adhesive that bonds the windshield glass to the vehicle body. Excess sealer/primer may drip or flow onto the windshield and cause a stain. Once the sealer/primer dries, it may appear to have etched the glass. Correction Note A "white" type of toothpaste is recommended for this repair. Gel-type toothpaste may provide less satisfactory results. Use a small amount of toothpaste on a soft, cotton cloth to polish the stained area. It may be necessary to wrap the cloth around a paint stir stick or a similar tool to reach the lower corners of the windshield glass. After polishing the glass, clean the inside of the windshield glass with a clean, damp, cotton cloth and verify all of the stain is removed. Do not use any cleaners or solvents - use only clean warm water. Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use: Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Page 766 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 5112 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Specifications Clutch Master Cylinder: Specifications Master Cylinder Retaining Nuts ........................................................................................................... ............................................................... 10-15ft. lbs. Page 3352 Fuel Supply Line: Description and Operation The fuel feed and return pipes and hoses extend from the fuel pump and sender to the TBI unit. They are secured with clamps and are routed along the frame side member. The vapor pipe and hoses extend from fuel pump and sender unit to the Evaporative Emission (EVAP) control vapor canister. Specifications Input Shaft: Specifications Input Shaft Bearing Retainer Bolts (204) ............................................................................................. ..................................................................... 7 ft. lbs. Removal and Installation Clutch Slave Cylinder: Service and Repair Removal and Installation When servicing the clutch actuator with hydraulic line intact, disconnect the clutch master cylinder pushrod from the clutch pedal in order to prevent damage to the actuator should the pedal be depressed. 1. Raise and support vehicle, then remove actuator cylinder to clutch housing nuts and actuator assembly. 2. Drive out hydraulic line to actuator retaining pin using a 7/64 inch punch. 3. Use hydraulic clutch line separator tool No. J-36221 or equivalent to disconnect actuator cylinder hydraulic line coupling, then remove line from clips if necessary. 4. Reverse procedure to install, noting the following: a. Torque actuator cylinder nuts to 13 ft. lbs. Engine - Tick Or Rattle/Detonation Or Rattle Noise Intermediate Shaft: All Technical Service Bulletins Engine - Tick Or Rattle/Detonation Or Rattle Noise FILE IN SECTION: 6 - Engine BULLETIN NO.: 23-61-11 DATE: June, 1995 SUBJECT: CPI Engine Noise (Install New Gears/New MEM-CALs) MODELS: 1992 Chevrolet and GMC Truck S/T, M/L Models 1992 Oldsmobile Bravada with 4.3L CPI Engine (VIN W - RPO L35) This bulletin is being revised to update engine scrapping information. Previous divisional publication numbers were: Chevrolet 92-244B-6 GM of Canada 93-6A-121 GMC Truck 92-6A-153A Oldsmobile 92-T-168 CONDITION Some 1992 model year 4.3L CPI engines may exhibit one or both of the following noises: I. A tick or rattle noise at idle or low engine speeds up to 1300 RPM. The noise may occur hot or cold in Park/Neutral or in gear. II. A detonation or rattling type noise under acceleration at engine speeds between 2000 - 2500 RPM. It is usually most noticeable at the shift points under moderate acceleration with the transmission torque converter unlocked. Premium grade fuel does not affect the noise. III. If an engine has both noises (conditions "I" and "II"), follow condition "II" for cause and correction instructions and information. CAUSE I. The most probable cause for the idle tick or rattle (condition I) is due to zero or near zero lash between the balance shaft drive gears. Some gears may feel as if the lash is acceptable but there is most likely an area on one of the teeth which is not meshing properly with the other gear. II. The source of the detonation or rattling type noise under acceleration between 2000 - 2500 RPM (condition II) is the rear balance shaft needle bearing. With some engines, the rear needle bearing is excited by a combination of factors (i.e., engine case, combustion events, balance shaft gear lash, valve train torque reversals, cam chain play, needle bearing clearance, etc.). Important: If there is any question about the proper diagnosis of the noise, call Technical Assistance. The unnecessary customer inconvenience and/or replacement of parts must be avoided. It is important to note that neither noise is a reliability or dependability concern. The noises are a customer pleasability issue only. The life of the engine will not be shortened due to the above causes. CORRECTION I. The following steps should be followed to correct an idle tick noise (condition I). 1. Remove the accessory drive belt. 2. Start the engine and note the noise. If it is still present proceed to step "3"; if not, proceed with diagnosis of accessory drive per the service manual procedures. Important: Do not allow the engine to operate for an extended period of time with the accessory drive belt off. Remember the water pump and fan are not functioning. Overheat will eventually occur. 3. Order GMSPO B/S Gear Kit # 12513234 and W/P; front cover gaskets. Use the following steps to replace the balance shaft gears. Page 3086 Catalytic Converter: Testing and Inspection NOTE Proper diagnosis for a restricted exhaust system is essential before any components are replaced. The following procedure(s) may be used for diagnosis: Exhaust System Check CHECK AT A.I.R. PIPE - Remove the rubber hose at the exhaust manifold A.I.R. pipe check valve and remove check valve. - Connect a fuel pump pressure gauge to a hose and nipple from a Propane Enrichment Device. - Insert the nipple into the exhaust manifold A.I.R. pipe. CHECK AT 02 SENSOR - Carefully remove O2 sensor. - Install Exhaust Backpressure Tester in place of 02 sensor. - After completing the diagnosis described below, be sure to coat threads of 02 sensor with anti-seize compound prior to re-installation. DIAGNOSIS - With the engine idling at normal operating temperature, transaxle in park or neutral, observe the exhaust system backpressure reading on the gauge. The reading should not exceed .5 psi or 3.4 kPa. Increase engine speed to 3000 rpm and observe gauge. The reading should not exceed .75 psi or 5 kPa. - If the backpressure exceeds the given specifications, a restricted exhaust system is indicated. - Inspect the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure. - If there are no obvious reasons for the excessive backpressure, a restricted catalytic converter should be suspected, and replaced. WITH VACUUM GAUGE Engine at normal operating temperature: Connect a vacuum gauge to any convenient vacuum port on intake manifold. - Run engine at 1000 rpm and record vacuum reading. - Increase rpm slowly to 2500 rpm. Note vacuum reading at a steady 2500 rpm - If vacuum at 2500 rpm decreases more than 3" Hg, from reading at 1000 rpm, the exhaust system should be inspected for restrictions - Disconnect exhaust pipe from engine and repeat Step 2 & 3. If vacuum still drops more than 3" Hg, with exhaust disconnected, check for exhaust manifold restriction and valve timing. Page 2809 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. With A-6 Compressor Compressor Clutch Hub: Specifications With A-6 Compressor Clutch Plate Air Gap ....................................................................................................................................................... 0.56-1.34 mm (0.022-0.057 inch) Page 5093 Starter Solenoid: Specifications Hold-In Windings And Pull-In Windings Amperes Hold-In Windings And Pull-In Windings Amperes Hold-In Windings Pull-In Windings Starter Identification Number 10455016 13-19 A 23-30 A 10455017 13-19 A 23-30 A 10455018 13-19 A 23-30 A 10455024 10-20 A 50-65 A 10455025 10-20 A 50-65 A 10455048 10-20 A 50-65 A Locations LH I/P Harness Wiring Page 8122 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 8409 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Wheels/Tires - Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Page 7532 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Page 4772 Brake Hose/Line: Specifications Rear Brake Hose To Bracket Bolt 13 ft.lb Front Brake Hose Bolt 32 ft.lb Coolant Temperature Switch Engine Wiring, LH Side Hydro-Boost Hydraulic Brake Booster: Description and Operation Hydro-Boost Fig. 1 Cross-sectional View Of Bendix Hydro-Boost Unit The Hydro-Boost system, Fig. 1, provides an additional cylinder in the brake system. This cylinder contains no brake fluid. The Hydro-Boost cylinder is hydraulically operated, by pressurized fluid from the power steering pump, providing power assist to operate a dual master cylinder brake system. The booster is composed of two sections; the linkage section and the power section. The booster is designed so that if a total absence of power assist occurs, the brakes can be applied manually, but somewhat greater pressure on the brake pedal is required. Page 7620 Vehicle Speed Sensor/Transducer - Cruise Control: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 6322 12. Case sections (30 and 36). 13. Core (33). Install Or Connect 1. Core (33). - Add or replace Refrigerant Oil as necessary. 2. Case sections (30 and 36). 3. Screws (38). 4. Accumulator (6). 5. Blower assembly to the vehicle. 6. Screws (29) and nuts (37). Tighten Screws (29) to 3 Nm (27 in. lb.). - Nuts (37) to 2 Nm (18 in. lb.). 7. Compressor hose assembly (3) to accumulator. 8. Evaporator tube (5) to evaporator (10). Tighten Evaporator tube connection to 41 Nm (30 ft. lb.). - Compressor hose assembly to 41 Nm (30 ft. lb.). 9. Electrical connectors, as necessary. 10. Resistor (35). 11. Heater hoses to core. 12. Refill cooling system. 13. Refrigerant to the system. - Check the system for leaks. Page 6165 Compressor Clutch: Service and Repair With HR6-HE Compressor Clutch Plate and Hub Assembly Remove or Disconnect Clutch Plate And Hub Assembly Removal 1. Clamp the holding fixture J 33026 in a vise and attach compressor to holding fixture with thumb screws J 33026-1. 2. With center screw forcing tip in place to thrust against the end of the shaft, thread the Clutch Plate and Hub Assembly Installer-Remover J 33013-B into the hub. Hold the body of the remover with a wrench and turn the center screw into the remover body to remove the clutch plate and hub assembly. NOTICE: Do not drive or pound on the clutch hub or shaft. Internal damage to compressor may result. The forcing tip on J 33013-B remover-installer center screw must be flat or the end of the shaft/axial plate assembly will be damaged. 3. Remove the shaft key and retain for reassembly. Install or Connect Page 8537 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 8536 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Tires - Speed Rated Information Tires: All Technical Service Bulletins Tires - Speed Rated Information Group Ref.: 3 - Steering/Suspension Bulletin No.: 433502 Date: July, 1994 INFORMATION SUBJECT: SPEED RATED TIRES MODELS: 1995 AND PRIOR YEAR PASSENGER CARS AND LIGHT DUTY TRUCKS All original equipment passenger car and light duty truck tires used by General Motors have a speed rating symbol molded on their sidewall. This speed symbol, along with the tire's load index, make up the service description that follows the tire's size. The original equipment tire size, speed rating, and recommended inflation pressure are listed on the tire placard usually located on the driver's door edge. WHEN REPLACING TIRES, NEVER INSTALL A TIRE THAT IS A SMALLER SIZE OR LESSER SPEED RATING THAN THAT USED AS ORIGINAL EQUIPMENT. As in the past, it is recommended that replacement tires have a TPC (Tire Performance Criteria) number on the sidewall that is identical to that on the original tires. Common speed rating on tires used by General Motors are as follows: (see illustration) IMPORTANT: Most base all season tires and touring tires used by GM are S rated. Performance tires will usually have a higher speed rating. High performance tires are usually Z rated. Z rated tires carry the Z symbol within the tire size, rather than after the size in the service description. These speeds apply only at the tire's full pressure. An underinflated tire will not meet its speed rating capability. Page 6182 J 24092 Pulley Hub Adapter Set 1. Clutch plate and hub assembly (2). Removing The Pulley Retainer Ring 2. Pulley bearing retainer (2) with J 6435. 3. Pulley (6). Removing The Pulley And Bearing - Install J 9395 over the end of the compressor shaft (38). Important Use J 9395 puller pilot to prevent internal damage to the compressor when removing the pulley. Do not use the pulley directly against the end of the shaft. - Place J 8433 over J 9395 for the regular V-groove pulley. - Place J 24092 over J 9395 for the multi-groove pulley. - Turn the screw on J 8433 to remove the pulley (6). Important When using J 24092, the puller arms must extend around to the rear side of the pulley. Do not attempt to pull the pulley off by engaging the puller arms in a multi-groove pulley. Description and Operation Fuel Pump Relay: Description and Operation OPERATION When the ignition key is first turned to the "ON" position, the control module will energize the fuel pump relay as long as the engine is cranking or running, and the control module is receiving distributor reference pulses. If there are no reference pulses, the control module will shut "OFF" the fuel pump relay within two seconds. An inoperative fuel pump relay can result in extended crank times, particularily if the engine is cold. The oil pressure switch will turn "ON" the fuel pump, as soon as oil pressure reaches about 28 kPa (4 psi). Page 8469 Door Switch: Locations RH Rear Door Jamb Switch In RH B-Pillar Page 5503 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 8365 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 7733 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 6907 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Locations Switch: Locations Anti-Lock Brake Components. In Front Axle Applicable to: 1992 Blazer & Jimmy Page 6304 Temperature Control Cable REMOVE OR DISCONNECT 1. Screws (50). - Pull control assembly away from Instrument panel. 2. Cable (53) from control assembly (49). 3. Vacuum connections from control assembly (49). 4. Electrical connections from control assembly (49). Page 6185 Compressor Clutch Bearing: Service and Repair With V5 Compressor Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. Removing Pulley Rotor & Bearing Assembly Retaining Ring 2. Remove rotor and bearing assembly retaining ring, using snap ring pliers J 6083. Installing Pulley Rotor/Bearing Puller Guide Page 6737 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 6139 Removing The Pulley And Bearing Retainer Ring 4. Bearing (5) from the pulley (6). - Remove the retaining ring (3). Removing The Bearing From The Puller - Pulley (6) to J 21352-A. - Drive the bearing (5) from the pulley (6) with J 9398-A and J 8092. Install or Connect Tools Required: J 6435 External Snap Ring Pliers J 8092 Driver Handle J 9481-A Pulley Bearing and Pulley Installer Installing The Pulley Bearing 1. Bearing (5) to the pulley (6) with J 8092 and J 9481-A. 2. Retainer ring (4) to the pulley (6). Control Module Replacement Engine Control Module: Service and Repair Control Module Replacement Figure 1 CAUTION [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, Do NOT touch the connector pins or soldered components on the circuit boards. NOTE When replacing a production control module with a service controller, transfer the broadcast code and production control module part number to the controller label. DO NOT record information on the access cover. REMOVE/DISCONNECT - Negative battery terminal. - Passenger side kick panel. - Hush panel if equipped. - Mounting screw. - Control module from mounting bracket. - VSS buffer connector and rotate control module to ease removal. - Control module harness connectors. - Mounting brackets and modules if equipped. - Remove new control module from its packaging and check the service number to make sure it is the same as the defective control module. - PROM removal. Refer to PROM (MEM-CAL) replacement. NOTE Replacement control module is supplied without a PROM, so care should be used when removing it from the defective control module, because it will be reused in the new control module. INSTALL/CONNECT - Mounting brackets and modules if equipped. - Control module harness connectors. - VSS buffer connector and rotate control module to ease installation. - Control module into mounting bracket. - Mounting screw. - Hush panel if equipped. - Passenger side kick panel. Page 5465 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 3801 (1994-1997). Design 2 1-2 accumulator assemblies with a composite (plastic) piston and an ovate wire outer spring, started May 11, 1998 (Julian Date 131), use service package P/N 24214343 (1998-1999). Notice: Failure to follow the above instructions may result in transmission distress. Parts Information Parts are currently available from GMSPO. Page 7321 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 2022 Parts are currently available from GMSPO. Calibration Information for 1992 Model Year Vehicles with Sleeve Bearing Engines: Torque Specifications Instrument Panel and Gauges - Revised Doesn't Light Test Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel and Gauges Revised Doesn't Light Test File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-05 Date: January, 1997 SERVICE MANUAL UPDATE Subject: Section 83C - Instrument Panel and Gauges Models: 1992 Chevrolet and GMC S/T Models This bulletin revises the diagnostic procedure "Cluster Display Does Not Light" for the Electronic Digital instrument Cluster as found on Page 8C-3 in 1992 Chevrolet Trucks S-10 Models, Service Manual ST 369-92. ^ Delete or cross-out the existing PROBLEM: Cluster Display Does Not Light. ^ Replace it with the revised PROBLEM: Page 7504 Use applicable labor time guide for labor hours. Page 45 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 8174 Door Switch: Locations Door Jamb Switch, LH Front In LH A-Pillar Diagram Information and Instructions License Plate Lamp: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 1115 - Support the GM Oil Life System, thereby minimizing the replacement of engine oil, before its life has been depleted. - Reduce the duplication of requirements for a large number of internal GM engine oil specifications. International Lubricants Standardization and Approval Committee (ILSAC) GF-5 Standard In addition to GM dexos 1(TM), a new International Lubricants Standardization and Approval Committee (ILSAC) standard called GF-5, was introduced in October 2010. - There will be a corresponding API category, called: SN Resource Conserving. The current GF-4 standard was put in place in 2004 and will become obsolete in October 2011. Similar to dexos 1(TM), the GF-5 standard will use a new fuel economy test, Sequence VID, which demands a statistically significant increase in fuel economy versus the Sequence VIB test that was used for GF-4. - It is expected that all dexos 1(TM) approved oils will be capable of meeting the GF-5 standard. However, not all GF-5 engine oils will be capable of meeting the dexos 1(TM) specification. - Like dexos(TM), the new ILSAC GF-5 standard will call for more sophisticated additives. The API will begin licensing marketers during October 2010, to produce and distribute GF-5 certified products, which are expected to include SAE 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30 oils. Corporate Average Fuel Economy (CAFE) Requirements Effect on Fuel Economy Since CAFE standards were first introduced in 1974, the fuel economy of cars has more than doubled, while the fuel economy of light trucks has increased by more than 50 percent. Proposed CAFE standards call for a continuation of increased fuel economy in new cars and trucks. To meet these future requirements, all aspects of vehicle operation are being looked at more critically than ever before. New technology being introduced in GM vehicles designed to increase vehicle efficiency and fuel economy include direct injection, cam phasing, turbocharging and active fuel management (AFM). The demands of these new technologies on engine oil also are taken into consideration when determining new oil specifications. AFM for example can help to achieve improved fuel economy. However alternately deactivating and activating the cylinders by not allowing the intake and exhaust valves to open contributes to additional stress on the engine oil. Another industry trend for meeting tough fuel economy mandates has been a shift toward lower viscosity oils. dexos 1(TM) will eventually be offered in several viscosity grades in accordance with engine needs: SAE 0W-20, 5W-20, 0W-30 and 5W-30. Using the right viscosity grade oil is critical for proper engine performance. Always refer to the Maintenance section of a vehicle Owner Manual for the proper viscosity grade for the engine being serviced. GM Oil Life System in Conjunction With dexos (TM) Supports Extended Oil Change Intervals To help conserve oil while maintaining engine protection, many GM vehicles are equipped with the GM Oil Life System. This system can provide oil change intervals that exceed the traditional 3,000 mile (4,830 km) recommendation. The dexos (TM) specification, with its requirements for improved oil robustness, compliments the GM Oil Life System by supporting extended oil change intervals over the lifetime of a vehicle. If all GM customers with GM Oil Life System equipped vehicles would use the system as intended, GM estimates that more than 100 million gallons of oil could be saved annually. GM dexos 2(TM) Information Center Website Refer to the following General Motors website for dexos 2(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 2(TM) Engine Oil Trademark and Icons Page 8127 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 4171 Clutch Pedal Assembly: Service and Repair Hydraulic Clutch System 1. Disconnect battery ground cable, then remove lower filler panel(s) or steering column covers. Remove lower left side of air conditioning duct if necessary to gain clearance. 2. Remove clutch start switch, noting position for installation reference, then remove clutch master cylinder push rod from pedal. 3. Remove clutch pedal nut, bolt and braces, noting positions for installation reference, then the pedal and spring. When removing bolt, slide a similar long rod or screw into bracket to keep parts together and in order. 4. Reverse procedure to install. Torque clutch pedal nut to 26 ft. lbs. 5. Remove bushings and spacer, then the bumper, if worn or damaged. Page 4946 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 752 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 6757 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 8402 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 3576 Ignition Coil: Testing and Inspection Fig. 11 Testing remote ignition coil Note Make sure the ignition switch is "OFF". 1. Disconnect the distributor lead and wiring from the ignition coil. 2. Connect a suitable ohmmeter as shown in step 1. Use the high scale. The reading should be infinite. If not, replace coil. 3. Connect ohmmeter as shown in step 2. Use the low scale. The reading should be very low or zero. If not, replace coil. 4. Connect ohmmeter as shown in step 3. Use the high scale. The meter should not read infinite. If it does, replace coil. 5. Reconnect the distributor lead and wiring from the ignition coil. Page 5672 Fig. 3 Retaining ring & dust cover removal 1. Remove adjuster plug lock nut from adjuster plug, Fig. 2. 2. Remove adjuster plug, spring and rack bearing. 3. Remove retaining ring from valve bore of housing and dust cover from bottom, Fig. 3. 4. While holding stub shaft, remove hex lock nut from pinion and valve assembly. Stub shaft must be held to prevent damage to pinion teeth. 5. Use an arbor press on threaded end of pinion until it is possible to remove dust seal, shaft seal and bearing assembly. Do not hammer or pound on pinion and valve assembly. Do not remove pinion and valve assembly from housing. press only far enough to allow bearing and seal removal. 6. Reverse procedure to install, noting the following: a. Lubricate seals, stub shaft and dust seal area with multi-purpose grease. b. Lubricate rack bearing, adjuster spring and adjuster plug with lithium grease. c. With rack center in gear assembly, turn adjuster plug clockwise until it bottoms in gear assembly, then back off 50-70 degrees (approximately one flat). Check rotational torque on pinion. Maximum pinion preload torque is 16 inch lbs. Page 1674 27. Balance shaft rear bearing using J 38834 and J 26941. Important - The balance shaft and both bearings are serviced only as a complete package. - Use only the correct tools for bearing and shaft installation. - The front bearing must not be removed from the balance shaft. - The balance shaft drive and driven gears are serviced only as a set. The set includes the balance shaft driven gear bolt. Clean All traces of old gasket material from gasket sealing surfaces. Inspect Balance shaft drive and driven gears for nicks and burrs. Install Tools Required: J 23523-E Torsional Damper Puller and Installer. J 38834 Balance Shaft Bearing Service Kit. J 36996 Shaft Installer J 8092 Driver Handle J 35468 Crankshaft Seal Installer Page 8132 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 4577 Symbol Identification Page 6635 Rear Speaker Wiring (Except Extended Cab) Page 5889 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Locations Power Steering Pressure Switch Wiring Page 1337 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 6444 Refrigerant: Service Precautions WARNINGS: - Air conditioning systems contain Refrigerant-12. This is a special mixture which requires special handling procedures to avoid personal injury. - Always wear goggles and wrap a clean cloth around fittings, valves, and connections when performing work that involves opening the refrigerant system. - Always work in a well ventilated area and avoid breathing any refrigerant fumes. - Do not weld or steam clean on or near any vehicle-installed air conditioning lines or components. - If Refrigerant-12 should come in contact with any part of the body, flush the exposed area with water and immediately seek medical help. CAUTIONS: - All Refrigerant-12 drums are shipped with a heavy metal screw cap. The purpose of the cap is to protect the valve and safety plug from damage. It is good practice to replace the cap after each use of the drum. - If it is necessary to transport or carry any container of Refrigerant-12 in a vehicle, do not carry it in the passenger compartment. - See the manufacturer's guide-lines for storage, transportation and the maximum temperature to which the container can be exposed. - If the occasion ever arises to fill a small Refrigerant-12 drum from a large one, never fill the drum completely. Space should always be allowed above the liquid for expansion. Page 6183 Removing The Pulley And Bearing Retainer Ring 4. Bearing (5) from the pulley (6). - Remove the retaining ring (3). Removing The Bearing From The Puller - Pulley (6) to J 21352-A. - Drive the bearing (5) from the pulley (6) with J 9398-A and J 8092. Install or Connect Tools Required: J 6435 External Snap Ring Pliers J 8092 Driver Handle J 9481-A Pulley Bearing and Pulley Installer Installing The Pulley Bearing 1. Bearing (5) to the pulley (6) with J 8092 and J 9481-A. 2. Retainer ring (4) to the pulley (6). Campaign - 02-313 Stop Delivery Notice Update Fuel Level Sensor: All Technical Service Bulletins Campaign - 02-313 Stop Delivery Notice Update ** ADMINISTRATIVE MESSAGE 01-277 CREATED ON 9/5/91 AT PAGE 1 OF 1 TO: ALL CHEVROLET DEALERS SUBJECT: STOP DELIVERY NOTICE 1992 S/T TRUCKS THIS IS WITH FURTHER REFERENCE TO THE 1992 S/T TRUCK STOP DELIVERY DCS ADMIN MESSAGE 01-258 DATED 8/22/91 SENT TO ALL CHEVROLET DEALERS. SELECT DEALERS WERE ADVISED IN DCS MESSAGE 02-313 DATED 9/5/91 OF PRODUCT CAMPAIGN 92C02 FUEL LEVER SENDER ARM/TANK INTERFERENCE. THIS DCS INCLUDED INVOLVED DEALER CODES AND INVOLVED VIN'S. ANY DEALER NOT RECEIVING DCS ADMIN MESSAGE 02-313 HAS NO INVOLVED VEHICLES ASSIGNED AND VIN'S WHICH FALL WITHIN THE ORIGINAL VIN RANGES LISTED BELOW ARE RELEASED FROM THE STOP DELIVERY. ASSEMBLY PLANT STARTING VIN ENDING VIN PONTIAC WEST N0100014 N0101228 MORAINE N2100052 N2101700 SHREVEPORT N8100014 N8101560 PLEASE COMMUNICATE THIS INFORMATION TO ALL DEALERSHIP MANAGEMENT IMMEDIATELY UPON RECEIPT. Page 2821 Idle Speed/Throttle Actuator - Electronic: Service and Repair NOTE - If IAC valve has been in service: Do NOT push or pull on the IAC valve pintle. The force required to move the pintle may damage the threads on the worm drive. - Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. - On this TBI unit, the IAC valve is flange mounted, with a dual taper, 10 mm diameter pintle. If replacement is necessary, only an IAC valve identified with the correct part number (having the appropriate pintle shape and diameter) should be used. Flange Mounted IAC Valve REMOVE/DISCONNECT - Electrical connector from IAC valve. - Screw assemblies and IAC valve. - IAC valve o-ring and discard. CLEAN - Both original and replacement IAC valves have a special factory applied thread-locking compound applied to the screw threads. If the valve removed from throttle body is being reinstalled, DO NOT remove thread-locking that may remain on the threads. - Clean IAC valve seating surfaces on throttle body to assure proper seal of new O-ring and contact of IAC valve flange. Adjusting IAC Valve Pintle NOTES - If IAC valve was removed during service, its operation may be tested electrically with the IAC/ISC Motor Tester (J-37027 or BT-8256K) or equivalent. Before installing IAC valve, measure the distance between the tip of valve pintle and mounting surface. If the dimension is greater than 28.0 mm (1.10 inches), valve pintle must be retracted to prevent damage to valve. This may be done electrically using an IAC/ISC Motor Tester or manually by exerting firm pressure, as shown in the illustration, with a slight side to side movement on valve pintle to retract it. - No physical adjustment of IAC valve assembly is required after installation. The IAC valve pintle is reset by turning the ignition "ON" for ten seconds and then "OFF". The control module then resets the pintle to the correct position. Proper idle regulation should result. INSTALL/CONNECT - Lubricate new o-ring with transmission fluid and install on IAC valve. - IAC valve to throttle body. - IAC valve attaching screw assemblies that have been coated with appropriate thread locking compound. Tighten screw assemblies to 3.0 Nm (27.0 lb-in). - Electrical connector to IAC valve. - Reset IAC valve pintle position: a. Disconnect negative battery for at least ten seconds to clear control module memory. (Ensure ignition is "OFF".) b. Reconnect negative battery cable. c. "START" engine and allow engine to reach operating temperature. Check for proper idle operation. Page 1814 1. Mounting to crossmember nut(s) and washer(s). 2. Mounting to transmission bolts and washers. -Raise the rear of the engine only enough to permit removal of the mounting. 3. Mounting. Install or Connect 1. Mounting. -Lower the rear of the engine. 2. Mounting to transmission bolts and washers. NOTICE: When fasteners are removed, always reinstall them at the same location from which they were removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be used. Fasteners that are not reused and those requiring thread locking compound will be called out. The correct torque value must be used when installing fasteners that require it. If the above condition are not followed, parts or system damage could result. 3. Mounting to crossmember nut(s) and washer(s). -Tighten fasteners to specifications as shown in the image. Page 7258 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Page 4396 Universal Joint: Service and Repair Double Cardan Type Fig. 1 Production Type Universal Joints Which Use Nylon Injection Rings In Place Of Snap Rings Fig. 2 Service Type Universal Joints (Internal Snap Ring Type) Before disassembling any universal joint, examine the assembly carefully and note the position of the grease fitting (if used). Also, be sure to mark the yokes with relation to the propeller shaft so they may be reassembled in the same relative position. Failure to observe these precautions may produce rough vehicle operation which results in rapid wear and failure of parts, and place an unbalanced load on transmission, engine and rear axle. When universal joints are disassembled for lubrication or inspection, and the old parts are to be reinstalled, special care must be exercised to avoid damage to universal joint spider or cross and bearing cups. Some driveshafts use an injected nylon retainer to hold the bearing cups. When service is necessary, pressing the cups out will sheer the nylon retainer, Fig. 1. Replacement with the conventional steel snap ring type is then necessary, Fig. 2. Fig. 9 Double Cardan Universal Joint Exploded View The double cardan type joint, Fig. 9, incorporates two universal joints, a centering socket yoke, and center yoke at one end of the shaft. A single universal joint is used at the other end. Page 1654 Engine Broadcast Code Information (last three digits of the engine I.D. number located In front of the right cylinder head at deck height): WARRANTY INFORMATION Condition I - For vehicles repaired by changing balance shaft drive gears: Condition II - For vehicles repaired by installing a Goodwrench engine: Important: Applicable miscellaneous items, such as engine oil and engine coolant, should be added to the above part allowance amount and included in the Net Amount (DMN) column of the claim. PARTS INFORMATION Content: Cylinder and case, cylinder head assembly, crankshaft, crankshaft main and rod bearings, piston and connecting rod assembly, T Truck/L Van oil pan and screen assembly, camshaft, valve lifters, push rods, camshaft chain and sprockets, balance shaft, balance shaft drive gears, valve lifter retainer, front cover and pointer, valve rocker cover, oil fill cap, harmonic balancer. Additional Parts Required to Dress-Out the Goodwrench Engine: (Quantity: 1 each, except as noted) A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 6046 Accumulator HVAC: Service and Repair Evaporator And Blower Assembly Component View Accumulator Replacement Page 7822 Page 4788 Brake Master Cylinder: Description and Operation Master Cylinder The master cylinder is designed for a system using low drag calipers. In addition to the standard master cylinder functions, a quick take up feature is included on models with a vacuum booster. This provides a large volume of low pressure fluid to the wheels with the initial brake application. The large volume of fluid helps overcome the clearance created by the caliper pistons and rear brake shoes retracting. Page 6615 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: Customer Interest Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Page 59 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Diagram Information and Instructions Compact Disc Player (CD): Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 6026 Page 4684 Backing Plate: Service and Repair Backing Plate REMOVE 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove brake drum. See Brake Drum / Service and Repair. See: Brake Drum/Service and Repair 4. Remove brake shoes. See Brake Shoes / Service and Repair. See: Brake Shoe/Service and Repair 5. Disconnect hydraulic line at wheel cylinder. CAUTION: Do not pull metal line away from cylinder, as this may kink or bend line. Line will separate from cylinder when cylinder is moved away from brake backing plate. 6. Remove wheel cylinder-to-brake plate attaching screws, then the wheel cylinder. 7. Remove axle shaft. 8. Remove the four backing plate attaching bolts then remove the backing plate. INSTALL 1. Install backing plate and retaining bolts. 2. Install wheel cylinder. See Wheel Cylinder / Service and Repair. See: Wheel Cylinder/Service and Repair 3. Install brake shoes. See Brake Shoes / Service and Repair. See: Brake Shoe/Service and Repair 4. Install brake drum. See Brake Drum / Service and Repair. See: Brake Drum/Service and Repair 5. Install wheel and tire assembly. 6. Lower vehicle. Page 8611 Power Window Motor: Service and Repair Power Window Motor Replacement Tools Front Door Components NOTE: Images shown are for manual windows, power windows are similar. REMOVE OR DISCONNECT Page 6101 Blower Motor: Service and Repair Blower Case Replacement Air Distribution System Component View Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: Customer Interest Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 7621 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 7250 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Speedometer - Registers When Vehicle is Stationary Vehicle Speed Sensor: Customer Interest Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. P/S - Reduced Assist When Cold Power Steering Fluid: Customer Interest P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Page 6697 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 5379 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 2457 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Locations Distributor And Coil 4.3W Page 3646 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 1136 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Locations Timing Mark Page 7670 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 8303 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 318 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Removal Wheel Cylinder: Service and Repair Removal For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove drum. 4. Remove brake shoes. 5. Disconnect hydraulic line at wheel cylinder. CAUTION: Do not pull metal line away from cylinder, as this may kink or bend line. Line will separate from cylinder when cylinder is moved away from brake backing plate. 6. Remove wheel cylinder-to-brake plate attaching screws, then the wheel cylinder. Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: All Technical Service Bulletins Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Page 744 Symbol Identification Page 8669 Front Door Trim Panel Components Front Inner Panel Water Deflector Page 5513 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 4708 Hold-down Spring Tool Conventional pliers or needle nose locking pliers will work if a brake spring tool is not available. - Grasp the top the the spring with the plier, compress, and rotate. CAUTION: Excessive pressure can easily distort the top of the spring. Any distortion widens the slot which can cause the pin to pop out during normal operation. If the slot appears distorted or widened it must be replaced. Installation While holding the brake shoe against the backing-plate, insert the retaining pin from the rear of the backing-plate through the appropriate hole in the brake shoe webbing. Verify the shoe is resting squarely on the contact pads of the backing-plate. NOTE: A strip of duct tape placed across the backside of the pin and backing-plate will help keep the pin from inadvertently falling falling out and will free up a hand to help steady the shoe during the next step. - Place the hold-down spring and washers over the pin. - With the thumb of one hand hold the shoe steady while reaching around the backing-plate to hold the retaining pin steady. - Use your other hand to simultaneously compress and align the slot of the hold-down spring with the pin. - When the slot and pin are aligned, further compress the spring to clear the tip of the pin and then rotate the spring 90 degrees. - The slot and tip of the pin should now be opposing each other at a 90 degree angle. - Verify the tip of the retaining pin is locked into the indents on the surface of the hold-down spring. This will keep the retaining pin from twisting and inadvertently popping out. Locations Switch: Locations Anti-Lock Brake Components. In Front Axle Applicable to: 1992 Blazer & Jimmy Page 7503 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 6642 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 6442 procedures and short-cutting refrigerant recycling times. Use the following procedure for testing and correcting air contamination in your A/C service equipment. 1. Make certain that the ACR4 equipment has not been used for at least 12 hours. It is recommended that the equipment be left in an area where the temperature will remain constant overnight to allow the temperature of the refrigerant in the tank to stabilize. 2. Record the surrounding air temperature next to the ACR4 refrigerant tank. Important: A major assumption is that the ambient air temperature next to the tank represents the refrigerant temperature in the tank. Failure to take care in measuring the temperature could result in unnecessary work. 3. Close both liquid (blue) and vapor (red) valves on the ACR4 tank. 4. Disconnect low side (blue) service hose from the back of the ACR4. 5. Slowly disconnect the tank vapor hose (red) from the back of the ACR4 and connect it to the low side service port. 6. Open the vapor (red) valve on the tank and record the tank pressure on the low side gage. 7. Restore hoses to the original position. 8. Referring to the Table, find the ambient temperature measured in Step 2. Compare the pressure reading from Step 6 to the "maximum allowable pressure". If the pressure reading from Step 6 is less than the "maximum allowable pressure", no further action is necessary. Important: The closer the tank pressure is to the desired tank pressure, the better the A/C system will perform. 9. If the pressure reading from Step 6 exceeds the maximum allowable pressure from the Table, open both tank valves and operate the ACR4 through 4 or 5 evacuation cycles. This will activate the automatic air purge to lower the tank pressure. Important: Station should not be connected to vehicle. 10. Repeat the tank pressure checking procedure the next day to determine if the pressure has been reduced to acceptable levels. If the tank pressure has been reduced but is not acceptable, cycle with ACR4 through more evacuation cycles and recheck the next day. Continue process until acceptable pressure is obtained. If the tank pressure is not reduced through the evacuation cycling, then Kent-Moore should be contacted at 1-800-345-2233. Page 2364 Engine Sensor Locations. LH Front Of Engine Applicable to: Except 4.3L/V6-262 HP & 4.3L/V6-262 Turbo Engines Page 5693 Steering Wheel: Service and Repair 1. Disconnect battery ground cable. 2. Remove steering wheel trim pad retaining screws from underside of steering wheel spokes, then lift off trim pad and remove wiring connector, if equipped. 3. Remove snap ring and nut from steering shaft. 4. Remove steering wheel using steering wheel puller tool No. J-1859-03 or equivalent. 5. Reverse procedure to install. Electrical Specifications Throttle Position Sensor: Electrical Specifications The throttle position sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Locks - Key Code Security Rules and Information Key: Technical Service Bulletins Locks - Key Code Security Rules and Information INFORMATION Bulletin No.: 10-00-89-010 Date: May 27, 2010 Subject: Key Code Security Rules and Information on GM KeyCode Look-Up Application (Canada Only) Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saturn and Saab 2002 and Prior Isuzu Attention: This bulletin has been created to address potential issues and questions regarding KeyCode security. This bulletin should be read by all parties involved in KeyCode activity, including dealer operator, partner security coordinator, sales, service and parts departments. A copy of this bulletin should be printed and maintained in the parts department for use as a reference. Important U.S. dealers should refer to Corporate Bulletin Number 10-00-89-009. Where Are Key Codes Located? General Motors provides access to KeyCodes through three sources when a vehicle is delivered to a dealer. Vehicle KeyCodes are located on the original vehicle invoice to the dealership. There is a small white bar coded tag sent with most new vehicles that also has the key code printed on it. Dealerships should make a practice of comparing the tag's keycode numbers to the keycode listed on the invoice. Any discrepancy should be reported immediately to the GM of Canada Key Code Inquiry Desk. Remember to remove the key tag prior to showing vehicles to potential customers. The third source for Key codes is through the GM KeyCode Look-Up feature within the OEConnection D2DLink application. KeyCode Look-Up currently goes back 17 previous model years from the current model year. When a vehicle is received by the dealership, care should be taken to safeguard the original vehicle invoice and KeyCode tag provided with the vehicle. Potential customers should not have access to the invoice or this KeyCode tag prior to the sale being completed. After a sale has been completed, the KeyCode information belongs to the customer and General Motors. Tip Only the original invoice contains key code information, a re-printed invoice does not. GM KeyCode Look-Up Application for GM of Canada Dealers All dealers should review the General Motors of Canada KeyCode Look-Up Policies and Procedures (Service Policy & Procedures Manual Section 3.1.6 "Replacement of VIN plates & keys"). Please note that the KeyCode Access site is restricted. Only authorized users should be using this application. Please see your Parts Manager for site authorized users. KeyCode Look-Up currently goes back 17 years from current model year. Important notes about security: - Users may not access the system from multiple computers simultaneously. - Users may only request one KeyCode at a time. - KeyCode information will only be available on the screen for 2 minutes. - Each user is personally responsible for maintaining and protecting their password. - Never share your password with others. - User Id's are suspended after 6 consecutive failed attempts. - User Id's are disabled if not used for 90 days. - Processes must be in place for regular dealership reviews. - The Parts Manager (or assigned management) must have processes in place for employee termination or life change events. Upon termination individuals access must be turned off immediately and access should be re-evaluated upon any position changes within the dealership. - If you think your password or ID security has been breached, contact Dealer Systems Support at 1-800-265-0573. Page 5468 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 4842 Fig. 5 Brake Booster Lock Tab & Staking Positions 1. Lubricate inside diameter of diaphragm lip with a thin layer of silicone grease, then install diaphragm into the diaphragm support, Fig. 3. 2. Install diaphragm and diaphragm support onto power piston and pushrod assembly. 3. Install new diaphragm retainer. Ensure retainer is fully seated. 4. Install filter, reaction retainer, piston rod and reaction body retainer. 5. Apply silicone grease to the power piston bearing and install it into the rear housing, then install return spring. 6. Mount housings to holding fixture and turn fixture handle in a clockwise direction to lock the front and rear housings. 7. Stake housing in locations shown, Fig. 5. Do not stake a tab that has been staked previously. 8. Lubricate inside and outside edges of grommet and front housing seal, then install grommet and seal. 9. Install vacuum check valve, silencer and boot. 10. Ensure piston rod depth is within specifications using gauge tool No. J-37839 or equivalent. Tandem Diaphragm Type Disassembly Fig. 4 Brake Booster Holding Fixture Page 1342 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 7054 Page 5266 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 2524 Knock Sensor: Testing and Inspection Electronic Spark Control (ESC) Circuit Check Diagnosis By Symptom Audible Warning Device: Testing and Inspection Diagnosis By Symptom Fasten Belts Warning Alarm Does Not Operate Fasten Belts Warning Alarm Operates When Safety Belt Is Buckled Page 5397 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 1190 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Page 2868 Oxygen Sensor Location Page 7742 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 2887 Electronic Control Module A/T Control - DTC P0756 Diagnostic Tips Valve Body: Technical Service Bulletins A/T Control - DTC P0756 Diagnostic Tips INFORMATION Bulletin No.: 01-07-30-036H Date: January 29, 2009 Subject: Diagnostic Tips for Automatic Transmission DTC P0756, Second, Third, Fourth Gear Start Models: 2009 and Prior GM Passenger Cars and Light Duty Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with 4L60-E, 4L65-E or 4L70E Automatic Transmission (RPOs M30, M32 or M70) Supercede: This bulletin is being revised to add the 2009 model year and add details regarding spacer plates. Please discard Corporate Bulletin Number 01-07-30-036G (Section 07 - Transmission/Transaxle). Some dealership technicians may have difficulty diagnosing DTC P0756, 2-3 Shift Valve Performance on 4L60-E, 4L65-E or 4L70E automatic transmissions. As detailed in the Service Manual, when the PCM detects a 4-3-3-4 shift pattern, DTC P0756 will set. Some customers may also describe a condition of a second, third or fourth gear start that may have the same causes but has not set this DTC yet. Below are some tips when diagnosing this DTC: ^ This is a performance code. This means that a mechanical malfunction exists. ^ This code is not set by electrical issues such as a damaged wiring harness or poor electrical connections. Electrical problems would cause a DTC P0758, P0787 or P0788 to set. ^ The most likely cause is chips/debris plugging the filtered AFL oil at orifice # 29 on the top of the spacer plate (48). This is a very small hole and is easily plugged by a small amount of debris. It is important to remove the spacer plate and inspect orifice # 29 and the immediate area for the presence of chips/debris. Also, the transmission case passage directly above this orifice and the valve body passage directly below should be inspected and cleaned of any chips/debris. For 2003 and newer vehicles the spacer plate should be replaced. The service replacement spacer plate is a bonded style with gaskets and solenoid filter screens bonded to the spacer plate. These screens can help to prevent plugging of orifice # 29 caused by small debris or chips. ^ This code could be set if the 2-3 shift valve (368) were stuck or hung-up in its bore. Inspect the 2-3 shift valve (368) and the 2-3 shuttle valve (369) for free movement or damage and clean the valves, the bore and the valve body passages. ^ This code could be set by a 2-3 shift solenoid (367b) if it were cracked, broken or leaking. Refer to Shift Solenoid Leak Test in the appropriate Service Manual for the leak test procedure. Based on parts return findings, a damaged or leaking shift solenoid is the least likely cause of this condition. Simply replacing a shift solenoid will not correct this condition unless the solenoid has been found to be cracked, broken or leaking. It is important to also refer to the appropriate Service Manual or Service Information (SI) for further possible causes of this condition. Disclaimer Page 4761 reservoir fluid level to full only after installing new brake pads and/or shoes. A full reservoir is indicated on translucent, snap cover reservoirs by a fluid level even with the top level of the view window imprinted into the side of the reservoir. On screw top models in black or translucent plastic, the full level is just below the bottom of the filler neck. Parts Information Part Number Description 12377967 Brake Fluid Parts are currently available from GMSPO. Disclaimer Page 316 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Locations Power Steering Pressure Switch Wiring Page 759 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 3871 Page 6597 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 6708 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 8544 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 8417 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 7099 Page 8214 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 3577 Ignition Coil: Service and Repair Distributor And Coil 4.3L Engine REMOVE OR DISCONNECT - Coil to distributor lead at coil. NOTE Make sure ignition switch is "OFF". - Wiring connectors at side of the coil. - Nuts or screws holding coil bracket and coil to engine. - Coil bracket and coil. ^ Drill and punch out rivets holding coil to coil bracket. - Coil from coil bracket. INSTALL OR CONNECT - Coil to coil bracket with screws. - Coil and coil bracket to engine. Tighten screws to 10 N-m (89 lb. in.). - Wiring connectors to the coil. Assure connectors are fully seated and latched. - Distributor lead to coil. Assure lead is fully seated on coil tower. Front Suspension Suspension Strut / Shock Absorber: Service and Repair Front Suspension Fig. 14 Shock Absorber Replacement. 4 X 4 Models 4 X 2 MODELS 1. Raise and support vehicle. 2. Hold shock upper stem from turning with a wrench and remove nut, retainer and grommet. 3. Remove lower shock pivot bolts, then remove shock absorber from vehicle. 4. Reverse procedure to install. Torque upper attaching nut and lower attaching bolts to specification. 4 X 4 MODELS Refer to Fig. 14 for shock absorber replacement procedure on 4 x 4 vehicles. Windshield - Two-Part Urethane Adhesive For Installation Windshield: All Technical Service Bulletins Windshield - Two-Part Urethane Adhesive For Installation File In Section: 10 - Body Bulletin No.: 73-10-54 Date: May, 1997 INFORMATION Subject: Two-Part Urethane Adhesive For Windshield Installations Models: 1997 And Prior Passenger Cars and Trucks (Using Urethane Adhesive To Retain Windshields) General Motors passenger cars and trucks use urethane adhesive as a means to retain the windshield in the body opening. The urethane adhesive is used to bond the windshield in the opening, increasing vehicle structure. The current recommended urethane adhesive, GM P/N 12346284, is a one-part moisture cure product that requires a minimum curing period of 6 hours at room temperature before returning the vehicle to the customer. Increasing customer demands for faster service in recent years have resulted in quicker cure two-part urethane adhesives. Essex Beta Seal U216* (two-part urethane adhesive) meets the General Motors 3651M Specification (Performance Requirements for Stationary Glass Bonding Adhesive System Service) and can be used when the customer demands quicker repair of the vehicle than the current one-part materials can provide. Either of these products can be used when glass replacement is performed. The differences between these products are as follows: The CURRENT URETHANE ADHESIVE KIT, GM P/N 12346284, IS A ONE-PART ADHESIVE. It includes the necessary glass and pinchweld primers and is specified in Service Manuals for General Motors' vehicles. Since this is a "moisture cure" product, the curing time for this one-part material will vary with changes to either temperature or humidity. The REQUIRED TIME FOR THIS ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. ESSEX BETA SEAL U216 IS A TWO-PART ADHESIVE MATERIAL THAT PROVIDES FOR A ONE (1) TO ONE AND ONE HALF (11/2) HOUR CURE BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This product also requires primers on the glass and pinchweld surfaces. This product requires a special applicator for the mixing and dispensing of the adhesive. When using this (or any) product, make sure to follow the manufacturer's directions for application and drying times. Parts Information Parts are currently available from GMSPO. * We believe this source and their product to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such products which may be available from other sources. Page 7467 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 7409 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 6292 Owners of some 1986-92 S/T Trucks equipped with air conditioning may comment on loose or binding temperature control or HVAC mode selection levers. These conditions may be caused by broken housing bosses at the plate mounting screws on the A/C control (Figure 3). The result may be inability to actuate certain HVAC modes or obtain maximum heating or cooling. Previously it was necessary to replace the complete A/C control assembly to correct this condition. The control assembly included the valves, switches, bezel and lighting. The housing, P/N 16074394, is now available allowing this condition to be corrected when other parts of the control are operating properly. Partial disassembly of the A/C control is required. SERVICE PROCEDURE: 1. Remove the A/C control assembly from the instrument panel. Page 4944 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 7333 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7386 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 6834 Parts Information Parts required to complete this special coverage are to be obtained from General Motors Service and Parts Operations (GMSPO). Customer Notification General Motors will notify customers of this special coverage on their vehicles. Service Procedure Replacement of interior door handle assembly(s) Provide the customer with one or two interior front door handle assemblies. The customer is to self-install the assemblies or pay the dealer for the installation. Application of Lithium Grease Apply lithium based lubricant to the door handle springs. The lubricant should be applied so that it works into and between the spring coils, allowing the coils to move past each other freely. Claim Information Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: All Technical Service Bulletins Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Page 5474 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7222 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 2558 Throttle Position Sensor: Service and Repair Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 5659 Steering Gear: Adjustments Saginaw Recirculating Ball Gear Over-Center Preload Fig. 2 Steering gear adjustments Prior to adjusting the steering gear, all outside loads must be removed. 1. Turn steering wheel gently from one stop over to other. Turn wheel back exactly half-way to center position. 2. Turn over center adjuster screw, Fig. 2, clockwise to take out all lash between ball nut and pitman shaft sector teeth. 3. Tighten jam nut to specifications. 4. Check torque at steering wheel, taking highest reading as wheel is turned through center position. 5. If necessary, loosen jam nut and adjust the over-center adjuster screw to obtain proper torque of 16 inch lbs. Tighten jam nut and recheck reading through center of travel. 6. If maximum torque is exceeded, turn the over-center adjuster screw counterclockwise, then come up on adjustment by turning jam nut clockwise. 7. Install pitman arm onto shaft, lining up marks made during removal. Worm Bearing Preload Fig. 2 Steering gear adjustments Page 1319 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Locations Oil Pressure Switch (For Fuel Pump): Locations Rear Of Engine Oil Pressure Switch 4.3L Utility Page 6435 89-93 - Suction hose - 96068490 89-93 - Discharge hose - 96068489 Suction hose: 85-86 - 91172086 85-86 Dealer installed: 91172087 87-88 - 91172088 89-93 - w/turbo - 96069121 - w/o turbo - 91172089 Discharge hose: 85-86 - 91172082 85-86 Dealer installed: 91172083 87-88 - 91172084 89-93 - 96069024 1989-93 Tracker 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the Retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 550 grams (1.21 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer - 91172080 Adapter, Low Side - 91172092 Page 2717 Spark Plug: Description and Operation Spark Plug Identification Chart IDENTIFICATION Resistor-type, tapered-seat spark plugs are used on all engines. No gasket is used on these tapered seat plugs. Refer to image for an explanation of letter coding on spark plugs. A dot before the spark plug code or the letter "C" after the number in the code indicates the spark plug has a copper core. CONSTRUCTION AND OPERATION Normal or average service is assumed to be a mixture of idling, slow speed, and high speed operation with some of each making up the daily total driving. Occasional or intermittent high-speed driving is essential to good spark plug performance as it provides increased and sustained combustion heat that burns away any excess deposits or carbon or oxides that may have accumulated from frequent idling or continual stop and go or slow speed driving. Spark plugs are protected by an insulating boot made of special heat-resistant material which covers the spark plug terminal and extends over a portion of the plug insulator. These boots prevent flash-over with resultant missing of the engine, even though a film is allowed to accumulate on the exposed portion of the plug porcelains. DO NOT mistake corona discharge for flash-over or a shorted insulator. Corona is a steady blue light appearing around the insulator, just above the shell crimp. It is the visible evidence of a high-tension field, and has no effect on ignition performance. Usually it can be detected only in the darkness. This discharge may repel dust particles, leaving a clear ring on the insulator just above the shell. This ring is sometimes mistakenly regarded as evidence that combustion gases have blown out between the shell and the insulator. SPARK PLUG SELECTION Spark plus must operate within a certain temperature range if they are to provide the performance and service life expected of them. The spark plug selected for an engine is based on the normal service for which the engine is designed. The spark plug may not perform satisfactorily under other-than-normal operating conditions. For almost-exclusively city driving, a spark plug 1 step higher in heat range might deliver a longer service life than the spark plug recommended for normal operation. Conversely, a spark plug rated 1 step colder will perform better for heavy loads or continual high-speed driving. There are three rules to follow when selecting spark plugs for an engine in good condition: - Select a plug with a specific heat range. - Should spark plug overheating occur, select a spark plug that is one heat range lower than the specified range. - If fouling is a problem, select a spark plug that is one step higher that the specified range. Page 4860 Symbol Identification Page 5028 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 1529 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These A/C Recirculation Door - Water Leak Hood Hinge: Customer Interest A/C Recirculation Door - Water Leak File In Section: 1 - HVAC Bulletin No.: 56-12-04 Date: April, 1995 Subject: Water Leak at the A/C Recirculation Door (Install New Hood Hinge Seal) Models: 1983-93 Chevrolet and GMC Truck S/T Pickups 1983-94 Chevrolet and GMC Truck S/T Utilities 1991-94 Oldsmobile Bravada Built Prior to the Following VIN Breakpoints: Assembly Plant Division (Plant Code) VIN Breakpoint GMC Truck Pontiac West (0) R0525661 Chevrolet Pontiac West (0) R0168567 Oldsmobile Pontiac West (0) R0704953 GMC Truck Moraine (2) All Chevrolet Moraine (2) All Oldsmobile Moraine (2) All CONDITION Some owners may comment that they have a water leak at the kick panel vent when their A/C controls are in the MAX position and it is raining. CAUSE Water is entering the plenum and cowl area by way of the hood hinge. CORRECTION To correct this condition, remove the current hood hinge seal and replace with a redesigned hood hinge seal. The redesigned seal has foam flaps which restrict water entry. Service Procedure 1. Raise and support the hood. 2. Remove the cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. 3. Remove hood hinge bolts from hood (both sides). 4. Remove hood from vehicle. 5. Remove fender nut and bolt from hinge (both sides). 6. Remove hood hinge from vehicle (both sides). 7. Remove hood hinge seals and replace with redesigned hood hinge seals P/N's 15995797 (LH) and 15995798 (RH). Important: Be sure that hood hinge seals are properly seated and sealed or water leakage could recur. 8. Install hood hinges to vehicle. Important: Apply lubricant to the hood hinges around the hinge to fender bolts. 9. Install fender nuts and bolts to hood hinges. 10. Install hood hinges to hood bolts. Tighten the hinge to hood bolts to 25 Nm (18 lb.ft.). Page 2167 Coolant: Technical Service Bulletins Coolant - Information on Propylene Glycol Usage File In Section: 6 - Engine Bulletin No.: 43-62-01B Date: April, 1995 Subject: Propylene Glycol Engine Coolant Models: 1994 and Prior Passenger Cars and Trucks This bulletin is being revised to reflect most current information on propylene glycol engine coolant. Please discard Corporate Bulletin Number 4362O1A (Group Reference 6 - Engine). General Motors has been reviewing data supplied on the performance of propylene glycol engine coolant in GM vehicles. It is our conclusion that propylene glycol engine coolant will perform adequately under most vehicle operating conditions. As a result, propylene glycol engine coolant (meeting performance specification GM 1825M) may be used in GM vehicles and will not affect the warranty coverage. Prior to adding propylene glycol engine coolant to the cooling system, all the existing (ethylene glycol) coolant must be removed. This can be accomplished either by utilizing water-based coolant flushing equipment or "waterless quick change" equipment available in the GMDE program. As with any coolant change procedure, be sure to thoroughly purge the heater core and block as well as the radiator before attempting to convert the system to propylene glycol coolant. Freeze/Boil point levels are different for propylene glycol than for ethylene glycol engine coolant. To accurately determine freeze/boil protection level, it is imperative that coolants not be mixed. Removing all the used coolant as previously discussed resolves this concern. Freeze protection of propylene glycol cannot be determined using a standard hydrometer. Rather, a refractometer or test strip must be used. Propylene glycol engine coolants may be recycled in the same manner as conventional ethylene glycol coolant. No adverse effects will be encountered if these coolants are mixed prior to recycling, however, the ratio of propylene glycol coolant to ethylene glycol coolant should be kept low to minimize the effects on freeze point measurements. Specifications Clutch Slave Cylinder: Specifications Clutch Actuator Cylinder Nuts ............................................................................................................. ................................................................... 13 ft. lbs. Page 1091 Fluid - A/T: Fluid Type Specifications 4L60 & 4L60-E Transmission Fluid Type ............................................................................................................................................ ............................................................... Dexron IIE 4L80-E / -EHD Transmission Lubricant Type ..................................................................................................................................... ............................................................... Dexron II E Page 4510 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Interior Door Handle Spring - Early Breakage Front Door Interior Handle: All Technical Service Bulletins Interior Door Handle Spring - Early Breakage Group Ref.: Body Bulletin No.: 461601 Date: April, 1994 INFORMATION SUBJECT: INTERIOR DOOR HANDLE SPRING BREAKAGE MODELS: 1990-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1990-94 CHEVROLET AND GMC TRUCK S/T UTILITIES 1991-94 OLDSMOBILE BRAVADA Some vehicles may be found to have front side door interior door handles with broken springs. This condition tends to be associated with vehicles that experience high (frequent) usage of the door handle mechanism. To enhance spring durability, production vehicles are now receiving door handle assemblies with lithium grease added to the spring. The durability of replacement door handles obtained from GMSPO can be increased by adding lithium based lubricant to the door handle spring. The lubricant should be applied so that it works into and between the spring coils. This will allow the coils to move past each other freely, reducing spring breakage. SERVICE PARTS INFORMATION: P/N Description Qty Procure Locally Lithium Based As Needed Lubricant Page 3870 Page 1823 - Support the GM Oil Life System, thereby minimizing the replacement of engine oil, before its life has been depleted. - Reduce the duplication of requirements for a large number of internal GM engine oil specifications. International Lubricants Standardization and Approval Committee (ILSAC) GF-5 Standard In addition to GM dexos 1(TM), a new International Lubricants Standardization and Approval Committee (ILSAC) standard called GF-5, was introduced in October 2010. - There will be a corresponding API category, called: SN Resource Conserving. The current GF-4 standard was put in place in 2004 and will become obsolete in October 2011. Similar to dexos 1(TM), the GF-5 standard will use a new fuel economy test, Sequence VID, which demands a statistically significant increase in fuel economy versus the Sequence VIB test that was used for GF-4. - It is expected that all dexos 1(TM) approved oils will be capable of meeting the GF-5 standard. However, not all GF-5 engine oils will be capable of meeting the dexos 1(TM) specification. - Like dexos(TM), the new ILSAC GF-5 standard will call for more sophisticated additives. The API will begin licensing marketers during October 2010, to produce and distribute GF-5 certified products, which are expected to include SAE 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30 oils. Corporate Average Fuel Economy (CAFE) Requirements Effect on Fuel Economy Since CAFE standards were first introduced in 1974, the fuel economy of cars has more than doubled, while the fuel economy of light trucks has increased by more than 50 percent. Proposed CAFE standards call for a continuation of increased fuel economy in new cars and trucks. To meet these future requirements, all aspects of vehicle operation are being looked at more critically than ever before. New technology being introduced in GM vehicles designed to increase vehicle efficiency and fuel economy include direct injection, cam phasing, turbocharging and active fuel management (AFM). The demands of these new technologies on engine oil also are taken into consideration when determining new oil specifications. AFM for example can help to achieve improved fuel economy. However alternately deactivating and activating the cylinders by not allowing the intake and exhaust valves to open contributes to additional stress on the engine oil. Another industry trend for meeting tough fuel economy mandates has been a shift toward lower viscosity oils. dexos 1(TM) will eventually be offered in several viscosity grades in accordance with engine needs: SAE 0W-20, 5W-20, 0W-30 and 5W-30. Using the right viscosity grade oil is critical for proper engine performance. Always refer to the Maintenance section of a vehicle Owner Manual for the proper viscosity grade for the engine being serviced. GM Oil Life System in Conjunction With dexos (TM) Supports Extended Oil Change Intervals To help conserve oil while maintaining engine protection, many GM vehicles are equipped with the GM Oil Life System. This system can provide oil change intervals that exceed the traditional 3,000 mile (4,830 km) recommendation. The dexos (TM) specification, with its requirements for improved oil robustness, compliments the GM Oil Life System by supporting extended oil change intervals over the lifetime of a vehicle. If all GM customers with GM Oil Life System equipped vehicles would use the system as intended, GM estimates that more than 100 million gallons of oil could be saved annually. GM dexos 2(TM) Information Center Website Refer to the following General Motors website for dexos 2(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 2(TM) Engine Oil Trademark and Icons Page 343 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Interior - Seat Cover Wrinkle/Crease/Burn Info Seat Cover: Technical Service Bulletins Interior - Seat Cover Wrinkle/Crease/Burn Info INFORMATION Bulletin No.: 04-08-50-006D Date: September 09, 2010 Subject: Minor Wrinkles/Creases, Discoloration, Cigarette Burns and Customer Induced Cuts and Stains on Front and Rear Driver and Passenger Seats with Leather, Vinyl or Cloth Seat Covers Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2009 and Prior Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add a model year. Please discard Corporate Bulletin Number 04-08-50-006C (Section 08 - Body and Accessories). If a customer comes in to your dealership due to certain conditions of the seat covers (splits, wrinkles, loose stitching, etc.), you must examine the seat cover in order to determine the validity of the customer claim. Some components from the above listed vehicles have been returned to the Warranty Parts Center (WPC) and analysis of these parts showed "customer induced damage" or No Trouble Found (NTF). The dealer should pay particular attention to the following conditions: - Cigarette burns Page 4566 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 3888 Page 5571 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Page 1318 Symbol Identification Page 6321 Accumulator Replacement Evaporator And Blower Case Replacement Remove Or Disconnect 1. Discharge and recover refrigerant from the system. 2. Drain cooling system. 3. Heater hoses from core. 4. Resistor (35) with the wire attached. 5. Electrical connectors, as necessary. 6. Evaporator tube (5) from evaporator (10). 7. Compressor hose assembly (3) from the accumulator (6). 8. Screws (29) and nuts (37). 9. Blower assembly from the vehicle. 10. Accumulator (6). 11. Screws (38). Page 1584 Wheel Bearing: Service and Repair REAR WHEEL BEARINGS AND/OR HUB Fig. 2 Axle Shaft Bearing Removal Fig. 3 Axle Shaft Bearing Installation Fig. 4 Axle Shaft Seal Installation 1. Remove axle shaft as described under AXLE SHAFT. 2. Remove axle seal by prying behind seal steel case with a pry bar. Use caution to avoid damaging axle housing. 3. Using a puller and slide hammer, remove axle bearing, Fig. 2. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer No. tool J-23765, or equivalent, until bearing is seated in housing, Fig. 3. 5. Lubricate seal lips with gear lubricant, then position seal on axle shaft seal installer tool No. J-23771 or equivalent, and install in axle housing, tapping into place until seal is flush with axle housing, Fig. 4. 6. Reinstall axle shaft. Page 1772 This condition maybe attributed to belt interference between the water pump pulley and belt tensioner pulley (Figure 1) The belt tensioner pivots both directions from the center pivot axis which can result in the serpentine belt coming in contact with itself at the water pump pulley. To correct this condition, loosen the generator bracket bolts (3) and move the top of the bracket to its most outward position (Figure 1). This will move the tensioner pulley away from the water pump pulley increasing clearance, to eliminate contact. Tighten the generator bracket bolts after the bracket has been repositioned. NOTE: Some cleaning agents or mineral oils can attack the belt compound and should not be used in this location. This may be another contributor to premature wear. If a new serpentine belt is required for the chirping sound or premature wear. new accessory drive serpentine belts have been released to GMSPO. The new belts will supersede the existing part numbers. SERVICE PARTS INFORMATION: PART NO. DESCRIPTION QTY. 10210382 Belt-Fan w/o C60, C69 1 10210383 Belt-Fan w C60, C69 1 S/T and C/K An improved belt is available for use on 1990 through 1993 S/T and C/K trucks with L35, LB4, L03, or LO5 engines equipped with C60 (air conditioning) but without K19 (A.I.R.). The new belt is less prone to "chirping." If, after performing standard diagnostic procedures, a serpentine belt replacement is required, use P/N 10189265. NOTE: P/N 10189265 replaces P/N 10069211. Parts are currently available from GMSPO. WARRANTY INFORMATION: Page 5026 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 3149 EGR AND EVRV SOLENOID 4.3 L Page 8581 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 6692 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 859 Frame Angle Measurement (Express / Savana Only) ........ Page 8427 Parking Lamp: Component Tests and General Diagnostics Front Park And Side Marker Lamps Do Not Operate Rear Lamp Systems Do Not Operate Page 4390 Fig. 24 Lubrication Fittlng Adapter & Fitting Location Fig. 25 Lubrication Fitting Locations Lubrication of the constant velocity joints should not be overlooked during the regular service intervals recommended by the manufacturer. During lubrication, use only the type of lubricant recommended by the manufacturer. This lubricant is usually lithium type chassis grease. Lubrication fitting adapters and locations of the lubrication fittings are shown in Figs. 23, 24 and 25. Page 7957 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 7085 Customers should be urged to wash and dry their vehicles frequently and garage them, or at least cover them with a quality car cover when not in use. Vehicles in dealer inventories should be kept clean and dry. A vehicle that sits unattended, especially after the sun has dried any water on the body surface, is a target for acid rain damage. MATERIALS DESCRIBED IN THIS BULLETIN* WAX AND GREASE REMOVER - USE BELOW OR EQUIVALENT Dupont # 3919S, PPG # DX440, BASF # 900, SIKKENS # 6041 FINESSE POLISHES - USE BELOW OR EQUIVALENT Dupont # 1500S, 3000S; BASF # 563-808, 560-1502; PPG # DRX10; 3M PERFECT-IT * USE V.O.C. EQUIVALENTS IN STATES WITH V.O.C. RESTRICTIONS RAIL DUST REMOVER - USE BELOW OR EQUIVALENT Industrial Fallout Remover # 5029 Zep Corporation Atlanta, GA. Telephone # 404-352-1680 Stain Away # HBY 0160 Hornby Chemical Milwaukee, WI. Telephone # 414-462-2833 If the rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. PAINT GAGES - USE BELOW OR EQUIVALENT Elcometer Inc. 1893 Rochester Ind. Drive Rochester Hills, MI. 48309 (800) 521-0635 or (313) 650-0500 Zelcro, Ltd./Zormco 8520 Garfield Rd. Cleveland, OH 44125 (216) 441-6102 Delfesko Corp. 410 Cedar St. Ogdensburg, NY 13669 (800) 267-0607 or (613) 925-5987 Pro Motorcar Products Inc. 22025 US-19 North Clearwater, FL 34625 (800) 323-1090 (813) 726-9225 "We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources." Page 7227 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 1663 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 7429 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Oxygen Sensors - Silica Contamination Oxygen Sensor: Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Page 718 Throttle Position Sensor: Service and Repair Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 1988 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 6054 Air Door Actuator / Motor: Locations Panel Door Actuator Heater & A/C Components, Instrument Panel Behind Center Of I/P Page 5422 Symbol Identification Page 5167 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Page 5031 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 7171 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7542 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 6687 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 7216 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 749 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 2845 Manifold Pressure/Vacuum Sensor: Testing and Inspection Manifold Absolute Pressure Output Check Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures the changes in the intake manifold pressure which result from engine load (intake manifold vacuum) and rpm changes; and converts these into a voltage output. The control module sends a 5 volt reference voltage to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the control module knows the manifold pressure. At lower pressure output voltage will be about 1 to 2 volts. While at higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts.The MAP sensor is also used, under certain conditions, to measure barometric pressure, Aluminum Wheels - Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Driveline - Launch Shudder Pinion Flange: Customer Interest Driveline - Launch Shudder FILE IN SECTION: 4 - Drive Axle BULLETIN NO.: 56-41-02 DATE: July, 1995 SUBJECT: Driveline Launch Shudder (Install Newly Designed Propeller Shaft) MODELS: 1992-93 Chevrolet and GMC Truck S10803 Models (Pick-up, Regular Cab, and Long Bed) 1992-94 Chevrolet and GMC Truck S10653 Models (Pick-up, Extended cab, and Short bed) 1992-94 Chevrolet and GMC Truck T10653 Models (Pick-up, Extended cab, and Short bed) with 4.3L V-6 Engines (VINs W, Z - RPOs L35, LB4) and Automatic Transmission CONDITION Some owners of pick ups with 4.3L V-6 engines (RPOs L35, LB4), equipped with a two-piece rear propeller shaft and an automatic transmission, may experience a launch shudder condition. This condition may occur from 0-25 mph (0-40 kph) and is more noticeable during hard acceleration when the vehicle is heavily loaded, or when used as a tow vehicle. CAUSE This condition is caused by the driveline angle changes occurring during engine torque and vehicle payload. CORRECTION To repair this condition a newly designed rear propeller shaft and pinion flange is released for service to reduce driveline launch shudder during 0-25 mph (0-40 kph). SERVICE PROCEDURE Remove or Disconnect (Figures 1, 2, and 3) Tool Required: J 8614-01 Companion Flange Holder 1. Place the vehicle on a hoist that will allow free rotation of the rear wheels. 2. Remove both rear tire wheel and drum assemblies. 3. Remove and discard existing two piece rear propeller shaft assembly, retaining the straps and fasteners. 4. Measure the pre-load on the rear axle pinion flange using an inch pound torque wrench, the amount of torque required to turn the pinion (Figure M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot PROM - Programmable Read Only Memory: Customer Interest M/T - Neutral Gear Rattle, Replace Prom, Clutch & Pilot BULLETIN NUMBER: 92-7B-149A SECTION: 7B Manual Transmission NUMBER: 1 CORPORATE REFERENCE NUMBER: 2672O1R DATE: August 1993 SUBJECT: NEUTRAL GEAR RATTLE (REPLACE CLUTCH DISK, PROM AND PILOT BUSHING) MODELS: 1990-92 C/K AND 1990-92 S/T WITH 4.3L AND 5 SPEED MANUAL TRANSMISSION This bulletin cancels and replaces Truck Bulletin 92-7B-149 (corp. # 267201R) dated December 1992, and is being revised to add the 1992 model year S/T Trucks with 4.3L engines (RPO LB4) and to add the "Detonation and Neutral Gear Rattle Proms" section. CONDITION Some owners of 1990-92 C/K and 1990-92 S/T Trucks with 4.3L engines (RPO LB4) and 5-speed manual transmission (RPO's MG5, MY2) may comment that the transmission rattles when in neutral with their foot off the clutch pedal and the engine at idle. The customer may describe the rattle as loose bearings. CAUSE This rattle noise is created when the turning transmission gears contact against each other. The contact is created by the firing impulses of the engine which causes rapid acceleration and deceleration of the individual gears. CORRECTION This condition may be corrected by the installation of the following parts: - A revised clutch driven disc which features a live degree neutral stage. This neutral stage helps to smooth the rapid acceleration and deceleration of the individual transmission gears. - A revised PROM which raises engine idle speed to 650 RPM on C/K and 700 RPM on S/T. This increase in idle speed helps to smooth the engine firing pulses. - A clutch pilot bearing rather than a clutch pilot bushing. This bearing helps to isolate the transmission from the engine idle acceleration/deceleration. SERVICE PROCEDURE Important Incorrect engine idle can contribute to neutral gear rattle. Before installing the parts listed in this bulletin, refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 2, Driveability Symptoms "Rough, Unstable or Incorrect Idle Stalling" to verify there are no existing conditions contributing to a rough idle which may aggravate neutral gear rattle. Clutch Disc and Pilot Bearing Replacement: Refer to the appropriate year and model Service manual, Section 7C "Clutch Assembly and Pilot Bearing Replacement." Important C/K trucks require pressure plate P/N 15974649 which was first used in production mid-1991. 1990 and 1991 vehicles built prior to the following VIN breakpoints require installation of P/N 15974649 unless it has already been installed in a service repair: Ft. Wayne (Z) MZ516555 Oshawa (1) M1526826 Pontiac (E) ME51G465 PROM Replacement: Refer to the appropriate year Light Duty Truck Fuel and Emissions Service Manual, Section 3 "On-Vehicle Service, PROM". Cooling System, A/C - Aluminum Heater Cores/Radiators Radiator: Technical Service Bulletins Cooling System, A/C - Aluminum Heater Cores/Radiators INFORMATION Bulletin No.: 05-06-02-001A Date: July 16, 2008 Subject: Information On Aluminum Heater Core and/or Radiator Replacement Models: 2005 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2003-2005 HUMMER H2 Supercede: This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 05-06-02-001 (Section 06 - Engine/Propulsion System). Important: 2004-05 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX-COOL(R). Refer to the flushing procedure explained later in this bulletin. The following information should be utilized when servicing aluminum heater core and/or radiators on repeat visits. A replacement may be necessary because erosion, corrosion, or insufficient inhibitor levels may cause damage to the heater core, radiator or water pump. A coolant check should be performed whenever a heater core, radiator, or water pump is replaced. The following procedures/ inspections should be done to verify proper coolant effectiveness. Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if the radiator cap or surge tank cap is removed while the engine and radiator are still hot. Important: If the vehicle's coolant is low, drained out, or the customer has repeatedly added coolant or water to the system, then the system should be completely flushed using the procedure explained later in this bulletin. Technician Diagnosis ^ Verify coolant concentration. A 50% coolant/water solution ensures proper freeze and corrosion protection. Inhibitor levels cannot be easily measured in the field, but can be indirectly done by the measurement of coolant concentration. This must be done by using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale), or equivalent, coolant tester. The Refractometer uses a minimal amount of coolant that can be taken from the coolant recovery reservoir, radiator or the engine block. Inexpensive gravity float testers (floating balls) will not completely analyze the coolant concentration fully and should not be used. The concentration levels should be between 50% and 65% coolant concentrate. This mixture will have a freeze point protection of -34 degrees Fahrenheit (-37 degrees Celsius). If the concentration is below 50%, the cooling system must be flushed. ^ Inspect the coolant flow restrictor if the vehicle is equipped with one. Refer to Service Information (SI) and/or the appropriate Service Manual for component location and condition for operation. ^ Verify that no electrolysis is present in the cooling system. This electrolysis test can be performed before or after the system has been repaired. Use a digital voltmeter set to 12 volts. Attach one test lead to the negative battery post and insert the other test lead into the radiator coolant, making sure the lead does not touch the filler neck or core. Any voltage reading over 0.3 volts indicates that stray current is finding its way into the coolant. Electrolysis is often an intermittent condition that occurs when a device or accessory that is mounted to the radiator is energized. This type of current could be caused from a poorly grounded cooling fan or some other accessory and can be verified by watching the volt meter and turning on and off various accessories or engage the starter motor. Before using one of the following flush procedures, the coolant recovery reservoir must be removed, drained, cleaned and reinstalled before refilling the system. Notice: ^ Using coolant other than DEX‐COOL(R) may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50,000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX‐COOL(R) (silicate free) coolant in your vehicle. ^ If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost would not be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core and other parts. Page 2607 CMFI Intake Manifold Sensors/Valves Page 1393 ^ Always inspect and adjust the pressure when the tires are cold. ^ Vehicles that have different pressures for the front and the rear need to be adjusted after tire rotation. Improper tire inflation may result in any or all of the following conditions: ^ Premature tire wear ^ Harsh ride ^ Excessive road noise ^ Poor handling ^ Reduced fuel economy ^ Low Tire Pressure Monitor (TPM) Light ON ^ Low Tire Pressure Message on the Drivers Information Center (DIC) Disclaimer Page 4777 Brake Proportioning/Combination Valve: Adjustments Fig. 9 Height Sensing Proportioning Valve Fig. 10 Adjustment Gauge Installation The height sensing proportioning valve must be adjusted whenever the valve and/or linkage is disassembled or removed for service. In addition, adjustment should be checked if excessive front wheel lock-up is experienced with a lower than desired brake application rate when vehicle is at or near maximum GVWR. 1. Raise and support vehicle leaving wheels on, and allow axle to hang free (no load condition). 2. Remove lever retaining nut and disconnect lever from valve shaft, Fig. 9. 3. Rotate valve shaft to permit installation of correct adjustment gauge, Fig. 10, ensuring that D shaped hole of gauge is properly seated on valve shaft and that gauge tang engages mounting hole in valve. Adjustment gauges vary depending upon vehicle application. Correct gauge must be used to ensure proper operation of braking system. 4. Install lever on valve shaft by pressing plastic bushing and clip assembly over shaft serrations using C-clamp or suitable pliers. Do not press lever onto shaft using retaining nut, as adjustment of valve will be disturbed. 5. Install lever retaining nut and torque to 70-98 inch lbs. 6. Cut tang off adjustment gauge and allow valve to rotate freely. 7. Lower vehicle and test brakes. Page 3874 Page 863 Front Wheel Alignment Specifications Slip Yoke/U-Joint - Replacement and Servicing Universal Joint: Technical Service Bulletins Slip Yoke/U-Joint - Replacement and Servicing File In Section: 4 - Drive Axle Bulletin No.: 46-41-01 Date: September, 1994 INFORMATION Subject: Slip Yoke Replacement and U-Joint Servicing Models: 1995 and Prior Light Duty Trucks U-joints that are pressed out of the propeller shaft or slip yoke must not be re-used. When it is necessary to press out the u-joint to replace a slip yoke, a new u-joint must be installed. A new u-joint is necessary as the bearing cup seals and slingers are easily damaged. If these components are damaged, dirt and water can contaminate the bearing causing early bearing wear-out. Replacement of the rear u-joint is not required if the retaining straps holding the u-joint to the rear axle pinion flange are removed. Light duty trucks make use of three types of yokes: 1. Vented slip yoke. This yoke can be identified by a small hole in the center of the slip yoke welch plug. This yoke uses grease for internal lubrication. The internal splines of the yoke should be coated with a light covering of grease before installation to the output shaft. A small amount of grease may be forced from the vent hole during operation. No attempts should be made to plug the vent hole. 2. Non-vented slip yoke. This yoke has no vent hole and relies on transmission or transfer case fluid for internal lubrication. Grease should not be used on the yoke internal splines as it may contaminate the transmission or transfer case fluid. 3. Bolted or fixed yoke. This yoke does not slide so it needs no internal lubrication. The transmission/transfer case output shaft seal should be inspected for damage before installing the yoke. The seal lips should also be greased before yoke installation for longer seal life and better performance. Page 3776 Torque Converter Clutch Solenoid: Locations Torque Converter Clutch Solenoid (TCC) Inside automatic transmission attached to valve body. Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: Customer Interest Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Page 6096 1. Blower motor fan. 2. Blower motor (53). 3. Cooling tube. NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 4. Blower motor flange screws (87). - Tighten screws (87) to 2 Nm (18 in. lb.). 5. Electrical connector (77) to blower motor (53). - Check circuit operation. Page 4732 Brake Bleeding: Technical Service Bulletins Brakes - Revised 4WAL System Bleeding Procedure BULLETIN NUMBER: 93-5E-74 SECTION: 5E Antilock Brakes NUMBER: 3 CORPORATE REFERENCE NUMBER: 365003 DATE: May 1993 SUBJECT: REVISED 4WAL BRAKE SYSTEM BLEEDING PROCEDURE (INFORMATIONAL) MODELS: 1990-93 MIL, S/T AND 1992-93 C/K AND 1993 G MODELS WITH 4WAL THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 91-5E-23, CORPORATE NUMBER 065001R, DATED SEPTEMBER 1990 TO UPDATE THE BLEED PROCEDURE AND TO ADD MODELS SINCE EQUIPPED WITH 4WAL BRAKE SYSTEMS. ALL COPIES OF 91-5E-23 SHOULD BE DISCARDED. THIS BULLETIN ALSO UPDATES INFORMATION IN 1993 MIL SERVICE MANUAL X9330, 1993 S/T SERVICE MANUAL X9329, 1993 C/K SERVICE MANUAL X9331, 1993 G SERVICE MANUAL X9357, AND STG RWAL/4WAL 1988-1991 APPLICATIONS MANUAL 15005.05 (VERSIONS 2 TO 5). PLEASE PLACE A COPY OF THIS BULLETIN IN EACH MANUAL. THIS BULLETIN IS EQUIVALENT TO SERVICE MANUAL UPDATE (CORP. NO. 263003). This 4WAL brake system bleed procedure is the most efficient bleed procedure to date. The 4WAL Brake Pressure Modulator Valve (BPMV), formerly called Electro Hydraulic Control Unit (EHCU), should be bled after replacement or if air is suspected to be trapped inside the unit. There are two conventional methods to use when bleeding the 4WAL BPMV: (1.) Pressure Bleeding or (2.) Manual Bleeding. Important There are two internal bleed screws (brass colored), one on each side of the BPMV, that open internal channels. Open the internal bleed screws 1/4 to 1/2 turn before bleeding (Figure 2). New 4WAL BPMV's are shipped with the internal bleed screws open, so first close the internal bleed screws until snug, then open 1/4 to 1/2 turn. Note: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid Page 2626 Fuel Pressure Test Port: Service and Repair Fuel Pressure Connection CLEAN Area around fuel pressure connection with GM X-30A or equivalent. REMOVE OR DISCONNECT - Negative battery terminal. - Relieve fuel system pressure. - Fuel pressure connection and seal. Discard seal. INSTALL OR CONNECT - New seal on fuel pressure connection. - Fuel pressure connection in fuel rail. Tighten Fuel pressure connection assembly to 10.0 N-m (88 lb. in.). - Tighten fuel filler cap. - Negative battery terminal. INSPECT - Turn ignition switch to the "ON" position for two seconds, then turn to the "OFF" position for ten seconds. Again turn to the "ON" position, and check for fuel leaks. NOTE Any time the battery is disconnected, the programmed position of the IAC valve pintle is lost, and replaced with a default value. To return the IAC valve pintle to the correct position, perform the following procedure: - Disconnect negative battery for at least ten seconds to clear control module memory. (Ensure ignition is "OFF".) - Reconnect negative battery cable. - "START" engine and allow engine to reach operating temperature. Check for proper idle operation. Diagram Information and Instructions Map Light: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 4110 Figure 2 2. To verify that the spacer plate is peening evenly and the ball is sealing correctly, seat the check-ball on the spacer plate. Shine a beam of light on the opposite side and inspect for light between the spacer plate and check-ball (see Figure 2). No trace of light should be present. If light can be seen, a proper seal does not exist, and the spacer plate must be replaced. Service Manual Reference: Refer to the HYDRA-MATIC Automatic Transaxle/Transmission Diagnosis or Unit Repair section of your service manual for proper check-ball locations and functions. Locations A/C And Heater Wiring Locations Distributor And Coil 4.3W Page 5175 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 5663 2. Install exactly 1/2 the number of balls in each circuit, rocking worm shaft slightly to aid in installing balls. 3. Place about six balls in each return guide, using grease to hold balls in place. 4. Install return guides, clamp and screw. 5. Rotate worm through its complete travel several times to be sure balls are installed correctly and rotate freely. 6. Place upper bearing on worm shaft and slide worm shaft assembly into housing. 7. Place lower bearing in worm bearing adjuster and install bearing retainer. 8. Install adjuster assembly and locknut in housing. Tighten adjuster only enough to hold worm bearings in place. Final adjustment will be made later. 9. Turn worm shaft until center groove in ball nut lines up with center of pitman shaft bushing. 10. Install pitman shaft and lash adjuster with shim so that center tooth meshes with center groove in ball nut. 11. Install side cover with gasket on lash adjuster by turning adjuster counterclockwise. 12. Install side cover bolts and washers. 13. Turn lash adjuster so that teeth on shaft and ball nut engage but do not bind. 14. Install lash adjuster locknut loosely. 15. To protect pitman shaft seal from damage, cover shaft splines with masking tape. Slide new seal into place and seat it against shoulder in housing. 16. Install new worm shaft seal flush with surface of housing. 17. Fill gear housing with multi-purpose lubricant and adjust gear assembly as outlined previously. Page 5085 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 1158 Page 8176 Door Switch: Locations RH Front Door Jamb Switch In RH A-Pillar Body - TPO Fascia Cleaning Prior to Painting Rear Bumper Cover / Fascia: Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer P/S - Reduced Assist When Cold Power Steering Fluid: All Technical Service Bulletins P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Page 5495 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 4281 Fig. 9 Pinion depth gauge installation PINION DEPTH, ADJUST If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION, INSTALL 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. Page 8372 Side Marker Lamp: Electrical Diagrams Front Park And Marker Lamps HP Engine Positive Crankcase Ventilation Valve: Locations HP Engine Engine Compartment Components RH Front Top Of Engine Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 HP Engine Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Page 7561 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 2338 For vehicles repaired under warranty, use the table. Disclaimer Page 4718 Wheel Cylinder: Service and Repair Installation For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics 1. Wipe end of hydraulic line to remove any foreign matter, then place wheel cylinder in position. Enter tubing into cylinder and start threads on fitting. 2. Install wheel cylinder bolts and tighten to backing plate. 3. Tighten brake line. 4. Install brake shoes. 5. Install brake drum. 6. Install wheel and tire assembly. 7. Bleed the brake system. 8. Adjust parking brake. Page 6384 85-93 Suction hose - 94855765 85-92 Discharge hose - 94845943 1985-88 Sprint, 1989-93 Metro (M) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 500 grams (1.10 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-86 - 91172081 87-88 - 91172079 89-93 - 96068480 Adapter Fittings: Low Side - 91172092 85-88 - High Side - 91172094 89-93 - High Side - 52467941 0-Rings: Compressor - Small 0-rings (6 required) - 91172095 - Large 0-ring - 96068915 Receiver/Dryer (2) - 96068488 Page 4080 Torque Converter Clutch Solenoid: Locations Torque Converter Clutch Solenoid (TCC) Inside automatic transmission attached to valve body. Page 8210 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 5150 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Page 80 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 2226 Labor Operation: J3390 Use applicable labor time guide for labor hours. Page 5514 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 7877 Cluster Display Does Not Light. Page 632 Knock Sensor: Testing and Inspection Electronic Spark Control (ESC) Circuit Check Warner T-5 (77MM) 5 Speed Case: Specifications Warner T-5 (77MM) 5 Speed Shift Cover Retaining Bolts .................................................................................................................. .................................................................... 9 ft. lbs. Adapter Housing Bolts ...................................... ...................................................................................................................................................... 25 ft. lbs. Locations Oil Pressure Switch (For Fuel Pump): Locations Rear Of Engine Oil Pressure Switch 4.3L Utility Page 7587 Vacuum Vent Valve: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Temp Gage Indic. Hot W/ENG Cool Below Oper Temp and Ign In Run Temperature Gage Indicates Hot With Engine Coolant Below Operating Temperature And Ignition Switch In RUN Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Page 4883 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 8047 Page 959 Spark Plug: Description and Operation Spark Plug Identification Chart IDENTIFICATION Resistor-type, tapered-seat spark plugs are used on all engines. No gasket is used on these tapered seat plugs. Refer to image for an explanation of letter coding on spark plugs. A dot before the spark plug code or the letter "C" after the number in the code indicates the spark plug has a copper core. CONSTRUCTION AND OPERATION Normal or average service is assumed to be a mixture of idling, slow speed, and high speed operation with some of each making up the daily total driving. Occasional or intermittent high-speed driving is essential to good spark plug performance as it provides increased and sustained combustion heat that burns away any excess deposits or carbon or oxides that may have accumulated from frequent idling or continual stop and go or slow speed driving. Spark plugs are protected by an insulating boot made of special heat-resistant material which covers the spark plug terminal and extends over a portion of the plug insulator. These boots prevent flash-over with resultant missing of the engine, even though a film is allowed to accumulate on the exposed portion of the plug porcelains. DO NOT mistake corona discharge for flash-over or a shorted insulator. Corona is a steady blue light appearing around the insulator, just above the shell crimp. It is the visible evidence of a high-tension field, and has no effect on ignition performance. Usually it can be detected only in the darkness. This discharge may repel dust particles, leaving a clear ring on the insulator just above the shell. This ring is sometimes mistakenly regarded as evidence that combustion gases have blown out between the shell and the insulator. SPARK PLUG SELECTION Spark plus must operate within a certain temperature range if they are to provide the performance and service life expected of them. The spark plug selected for an engine is based on the normal service for which the engine is designed. The spark plug may not perform satisfactorily under other-than-normal operating conditions. For almost-exclusively city driving, a spark plug 1 step higher in heat range might deliver a longer service life than the spark plug recommended for normal operation. Conversely, a spark plug rated 1 step colder will perform better for heavy loads or continual high-speed driving. There are three rules to follow when selecting spark plugs for an engine in good condition: - Select a plug with a specific heat range. - Should spark plug overheating occur, select a spark plug that is one heat range lower than the specified range. - If fouling is a problem, select a spark plug that is one step higher that the specified range. Page 968 Valve Clearance: Specifications Valve Arrangement All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E Page 7261 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Page 5790 1. The tire must be in the relaxed position when the repair unit is installed (Do not spread the beads excessively). Two-Piece Plug and Repair Units 1. If applicable, install the repair unit so that the alignment is correct. 2. Center the repair unit over the injury and stitch down thoroughly with the stitching tool, working from the center out. 3. Being careful not to stretch the plug material, cut the plug flush with the outer tread. Combination Repair/Plug Units 1. Pull the plug through the injury until the repair just reaches the liner. Stitch down thoroughly. 2. Follow the repair material manufacturer's recommendations for further installation instructions. 2. Consult your repair material supplier for the proper stitching tool. Safety Cage Page 8568 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 2843 Engine Wiring, LH Side Page 7533 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Locations Switch: Locations Anti-Lock Brake Components. In Front Axle Applicable to: 1992 Blazer & Jimmy Steering/Suspension - Wheel Alignment Specifications Alignment: Technical Service Bulletins Steering/Suspension - Wheel Alignment Specifications WARRANTY ADMINISTRATION Bulletin No.: 05-03-07-009C Date: December 09, 2010 Subject: Wheel Alignment Specifications, Requirements and Recommendations for GM Vehicles Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks Supercede: This bulletin is being extensively revised to provide technicians and warranty administrators with an all inclusive guide for wheel alignments. PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. Please discard Corporate Bulletin Number 05-03-07-009B (Section 03 - Suspension). Purpose The purpose of this bulletin is to provide retail, wholesale and fleet personnel with General Motors' warranty service requirements and recommendations for customer concerns related to wheel alignment. For your convenience, this bulletin updates and centralizes all of GM's Standard Wheel Alignment Service Procedures, Policy Guidelines and bulletins on wheel alignment warranty service. Important PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. The following five (5) key steps are a summary of this bulletin and are REQUIRED in completing a successful wheel alignment service. 1. Verify the vehicle is in an Original Equipment condition for curb weight, tires, wheels, suspension and steering configurations. Vehicles modified in any of these areas are not covered for wheel alignment warranty. 2. Review the customer concern relative to "Normal Operation" definitions. 3. Verify that vehicle is within the "Mileage Policy" range. 4. Document wheel alignment warranty claims appropriately for labor operations E2000 and E2020. The following information must be documented or attached to the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 5. Use the proper wheel alignment equipment (preferred with print-out capability), process and the appropriate calibration maintenance schedules. Important If it is determined that a wheel alignment is necessary under warranty, use the proper labor code for the repair. E2000 for Steering Wheel Angle and/or Front Toe set or E2020 for Wheel Alignment Check/Adjust includes Caster, Camber and Toe set (Wheel alignment labor time for other component repairs is to be charged to the component that causes a wheel alignment operation.). The following flowchart is to help summarize the information detailed in this bulletin and should be used whenever a wheel alignment is performed. Coolant Temperature Sensor Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Sensor HP Engine RH Front Side Of Engine. Front Of Engine Applicable to: 4.3L/V6-262 HP Engine Page 6215 Details Of Stakes In Front Head For Clutch Coil - Stake size should be only one-half the area of the punch tip and be only approximately 0.28-0.35mm (0.010-0.015") deep. 6. Install rotor and bearing assembly and the clutch plate and hub assembly. Page 4458 Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Page 8805 Wiper Motor: Testing and Inspection Wiper Motor Bench Test Fig. 3 Permanent Magnet Type Windshield Wiper Motor W/Pulse Wipers WIPER MOTOR TEST There are two ways to test the wiper motor. The first way is to set up a power supply and resistance framework as shown in the Image. This set of voltages and resistances when applied to the different pins of the motor will cause the motor to run in its operating modes. The second way to test the motor is by using J34660-A. Windshield wiper tester J34660-A is set up to duplicate the parameters in the Image. By plugging the proper adapter into the motor, all of the modes of the wiper motor operation can be checked. After choosing one of the above systems, test the motor. If a problem with the motor is discovered, replace the circuit board with a known good board. If the motor does not operate properly, repair or replace the motor. Page 6508 Warranty Information The dealership will be reimbursed for the parts and labor, if applicable, through the submission of a regular warranty claim. All claims submitted must be supported by a signed customer work order. Purchase and installation of additional Hardware Packages is the responsibility of the customer. For Top Tether Hardware Packages installed in the United States, submit as a normal warranty claim using the labor operations and time allowances shown. Disclaimer Page 391 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 1773 For vehicles repaired under warranty for Noise use: Labor Operation: T7460 Labor Time: 0.2 hours Clean A/C pulley and inspect for proper alignment 0.2 hours Loosen and align P/S pump pulley (include R and R lower shroud) Note: T7460 is coded to base vehicle coverage in the warranty system. For vehicles repaired under warranty for replacing serpentine belt use: Labor Operation: J0667 Use applicable labor time guide for labor hours. Locations Air Intake Ducts 4.3W S/T Utility Page 8563 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 6839 Parts Information Parts required to complete this special coverage are to be obtained from General Motors Service and Parts Operations (GMSPO). Customer Notification General Motors will notify customers of this special coverage on their vehicles. Service Procedure Replacement of interior door handle assembly(s) Provide the customer with one or two interior front door handle assemblies. The customer is to self-install the assemblies or pay the dealer for the installation. Application of Lithium Grease Apply lithium based lubricant to the door handle springs. The lubricant should be applied so that it works into and between the spring coils, allowing the coils to move past each other freely. Claim Information Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Page 1149 C. Parts Information D. Warranty Information 1. Vehicle Still in Warranty 2. Customer Paid' Retrofitting Costs 3. Labor Time Information Notes on Retrofit Important: Before proceeding with any retrofit, make sure you have all component Parts required on hand to perform a proper and complete repair with Minimal downtime. R-12 Removal Prior to Retrofit To prepare a system for retrofitting, the R-12 must be recovered and the system must be completely evacuated. Evacuation is necessary to insure that small amounts of R-12 and air remaining in the system are removed. This will prevent cross contamination of the two refrigerants, which could lead to reduced A/C system reliability and performance. It is very important that the specified times for waiting after recovery and evacuation not be reduced. This time is required to sufficiently remove residual R-12 from the oil in the system. A considerable amount of testing has determined that the following procedure is required to achieve satisfactory results and conform to SAE J 1661: 1. Inspect Condition of Vehicle Install the gauge set on the high and low side ports. Use normal diagnostic procedures to find the cause of the vehicle's reported condition. One of three conditions will exist with the refrigerant system: a. System pressure correct, no leaks - proceed to Step 2 (Recovery). This would normally apply when: 1. The system must be recovered/recharged for a repair to a system other than the A/C system, or 2. Where the A/C system condition did not involve leaks, but requires recovery/recharge to replace a component. b. Compressor not operating, but some charge. Leak test to find the leak, complete Step 2 (Recovery), then correct the leak before proceeding with Step 3 (Conversion port installation). c. No charge in system - proceed with the Conversion port installation in Step 3. Use the ACR4 to evacuate for 5 minutes. If the leak can be heard, repair the leak. If the leak cannot be heard, charge with 1/2 pound of R-134a. Leak test with the J 39400 Leak Detector, recover the R-134a, repair any additional leaks found, and proceed with the evacuation in Step 5. 2. Recover the R-12 from the System Notice: THIS PROCEDURE IS DIFFERENT THAN THE NORMAL (NON-RETROFIT) RECOVERY PROCEDURE. R-12 will be recovered through the HIGH SIDE SERVICE PORT ONLY, WITH THE ENGINE RUNNING. Recovery through the low side will not effectively remove the R-12 from the accumulator, resulting in possible damage to the retrofitted system. Important: Vehicle must be above 50° F (10° C) to allow for complete recovery of the R-12. If it is not, either allow it to warm up in the shop overnight, or increase the evacuation time in Step 5.a to 30 minutes. a. Connect the recovery hose from the R-12 recovery cart (ACR3) to the middle port of the A/C gauge set. Open the oil drain valve on the ACR3 cart long enough to drain the oil. Failure to do so could cause excessive amounts of oil to build up in the separator, resulting in damage to the recovery cart compressor. b. Start the engine. Leave the hood up, and the windows open. On vehicles with manual A/C controls, set the A/C controls to normal A/C mode, high blower, and temperature control to full cold. On cars with automatic A/C controls, set the temperature to 75° F, "AUTO" mode, and manually select high blower. Page 5042 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Locations A/C And Heater Wiring Page 4947 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 8213 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Body - Vehicle Glass Distortion Information Front Corner Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 6764 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 5041 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 7722 Figure 7 Figure 8 Figure 9 Figure 10 Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Gauge: Customer Interest Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 6679 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 7367 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Rectangular Motor Wiper Motor: Testing and Inspection Rectangular Motor Diagnosis By Symptom Fig. 3 Connections to operate rectangular wiper motor independent of vehicle wiring On models with pulse wipers, check system operation with pulse control module removed. If problem is eliminated, pulse control is defective. Refer to Fig. 3, to check wiper motor independent of vehicle wiring. BLADES NO NOT RETURN TO FULL PARK POSITION 1. Loose wiper ground strap connection. 2. Defective wiper motor. HIGH SPEED TOO FAST 1. Defective wiper motor. MOTOR OPERATES AT LOW SPEED ONLY 1. Defective wiper switch. 2. Grounded wire between motor terminal 3 and wiper switch. 3. Defective wiper motor. MOTOR RUNS AT HIGH SPEED ONLY 1. Defective wiper switch. 2. Open circuit between motor terminal 3 and wiper switch. 3. Defective wiper motor. MOTOR WILL NOT SHUTOFF 1. Grounded wire between motor terminal 1 and wiper switch. 2. Defective motor park switch. 3. Defective wiper motor. WIPER INOPERATIVE OR INTERMITTENT 1. Blown fuse. 2. Open circuit in feed wire (No. 2 terminal on wiper motor). 3. Loose mounting of wiper switch. 4. Open circuit in wire to wiper switch (No. 1 terminal on wiper motor). 5. Defective wiper switch. 6. Poor solder connections at terminal board. 7. Defective wiper motor. Page 5097 Symbol Identification Specifications Shift Solenoid: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Page 7256 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 4389 Fig. 22 Relieving Binding Condition At Point C ASSEMBLY Ball Socket & Constant Velocity Joint During assembly, make sure that marks made during disassembly, Fig. 12, are aligned to maintain balance. 1. To install centering ball onto stud, use tool C-4365 or equivalent, and drive ball until it can be seen that ball has seated firmly against shoulder at base of stud. 2. To install cross assembly, install one bearing cup part way into one side of yoke and turn this yoke to the bottom. Insert cross into yoke so that the trunnion seats into bearing, Fig. 18. Install opposite bearing cup part way, Fig. 19. Make sure that both cross journals are started straight into both bearing cups. 3. Press bearing cups, while moving cross to ensure free movement of trunnions in bearing. If any binding is felt, stop pressing and check needle bearings to make sure that needle bearings have not been trapped under the ends of the cross journals. 4. As soon as one of the retaining ring grooves clears the inside of yoke, stop pressing and install retaining ring. 5. Continue to press until opposite retaining ring can be snapped into place. If difficulty is encountered, strike the yoke firmly in locations shown in Figs. 20, 21 and 22, to spring the yoke ears slightly. 6. Lubricate center ball and socket, and assemble other half universal joint, if disassembled. Lubrication Fig. 23 Lubrication Fitting Adapter Page 1165 Adapter, High Side - 91172093 0-Rings: Compressor - Small (6) - 91172095 Large - 96068915 Receiver/dryer (2) - 96068488 Suction hose - 96068490 Discharge hose - 96068489 Suction hose - 91172091 Discharge hose - 91172085 1985-89 Spectrum and 1990-93 Storm (R) 1. Using the Service Manual, remove the following components in the order given: a. Condenser (Storm) or radiator grille (Spectrum) (to be reinstalled). b. Triple switch (Storm) or dual pressure switch (Spectrum) (to be reinstalled). c. Receiver/dryer. d. Evaporator to compressor (suction) pipe. e. Check valve from high side service valve (discard). f. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High side adapter fitting (see Step 3 of the retrofit procedure for detailed installation instructions). Low Side - Part of suction hose c. Evaporator to compressor (suction) pipe, and new 0-rings. d. Receiver/dryer and 0-rings. e. Triple switch or dual switch, and new 0-ring. f. Condenser or radiator grille. R-134a amount: 91 - 500 grams (1.10 lb) 92-93 - 600 grams (1.32 lb) PAG oil amount: 150 cc (4.50 oz) Parts Required: Receiver/dryer: 85-89 - 97104795 90-91 - 97104797 92-93 - 97104798 Adapter, High Side: Page 8128 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 3014 Vehicle Speed Sensor: Service and Repair 1. Disconnect vehicle speed sensor electrical connector. 2. Remove sensor attaching bolt. 3. Using speed sensor remover and installer, tool No. J 38417, remove sensor, then O-ring seal. 4. Reverse procedure to install, coating the new O-ring seal with transmission fluid. Torque attaching bolt to 97 inch lbs. Page 1536 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Page 695 Speed Sensor And Backup Lamp Switch Wiring - Two-Wheel Drive Models Page 1164 89-93 - Suction hose - 96068490 89-93 - Discharge hose - 96068489 Suction hose: 85-86 - 91172086 85-86 Dealer installed: 91172087 87-88 - 91172088 89-93 - w/turbo - 96069121 - w/o turbo - 91172089 Discharge hose: 85-86 - 91172082 85-86 Dealer installed: 91172083 87-88 - 91172084 89-93 - 96069024 1989-93 Tracker 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the Retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 550 grams (1.21 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer - 91172080 Adapter, Low Side - 91172092 Page 5116 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 413 Symbol Identification Page 8292 Symbol Identification Page 7281 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 7343 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 42 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Page 848 Fig. 10 Windshield Wiper Switch Removal (Rear) REAR Refer to Fig. 10, for wiper switch replacement. 1. Disconnect battery ground cable. 2. Remove switch trim plate and screws from instrument panel. 3. Disconnect electrical connector, then remove switch. 4. Reverse procedure to install. Page 7520 Cruise Control Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 3130 Exhaust Pressure Regulator Vacuum Valve: Locations STD Engine Engine Compartment Components. RH Side Of Engine Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 Engine Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 8377 Side Marker Lamp: Description and Operation Roof Marker Lamps Voltage is applied through the TAIL LPS Fuse to the Light Switch at all times. With the Lamp Switch in PARK or HEAD, voltage is applied to the Park, Tail, Marker and License Lamps. Locations Timing Connector Tires - Correct Inflation Pressure Information Tires: All Technical Service Bulletins Tires - Correct Inflation Pressure Information INFORMATION Bulletin No.: 00-00-90-002J Date: January 28, 2009 Subject: Information on Proper Tire Pressure Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2009 and Prior HUMMER H2, H3, H3T 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years and clarify additional information. Please discard Corporate Bulletin Number 00-00-90-002I (Section 00 - General Information). Important: ^ Adjustment of tire pressure for a customer with a Low Tire Pressure Monitor (TPM) light on and no codes in the TPM system is NOT a warrantable repair. Claims to simply adjust the tire pressure will be rejected. ^ ALL tires (including the spare tire) MUST be set to the recommended inflation pressure stated on the vehicle's tire placard (on driver's door) during the PRE-DELIVERY INSPECTION (PDI). Recommended inflation pressure is not the pressure printed on tire sidewall. ^ Tires may be over-inflated from the assembly plant due to the mounting process. ^ Generally a 5.6°C (10°F) temperature change will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure change. ^ 2008-2009 HUMMER H2 Only - The H2 comes standard with Light Truck "D" Load Range tires with a recommended cold inflation pressure of 289 kPa (42 psi). These tires will alert the driver to a low pressure situation at roughly 262 kPa (38 psi) due to a requirement in FMVSS 138 which specifies a Minimum Activation Pressure for each tire type. This creates a relatively narrow window of "usable" pressure values and the warning will be more sensitive to outside temperature changes during the colder months. As with other cold temperature/tire pressure issues, there is nothing wrong with the system itself. If a vehicle is brought in with this concern, check for tire damage and set all tires to the Recommended Cold Inflation Pressure shown on the vehicle placard. Accurate tire pressures ensure the safe handling and appropriate ride characteristics of GM cars and trucks. It is critical that the tire pressure be adjusted to the specifications on the vehicle¡C■s tire placard during PDI. Ride, handling and road noise concerns may be caused by improperly adjusted tire pressure. The first step in the diagnosis of these concerns is to verify that the tires are inflated to the correct pressures. The recommended tire inflation pressure is listed on the vehicle¡C■s tire placard. The tire placard is located on the driver¡C■s side front or rear door edge, center pillar, or the rear compartment lid. Tip ^ Generally a 5.6°C (10°F) temperature increase will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure increase. ^ The definition of a "cold" tire is one that has been sitting for at least 3 hours, or driven no more than 1.6 km (1 mi). ^ On extremely cold days, if the vehicle has been indoors, it may be necessary to compensate for the low external temperature by adding additional air to the tire during PDI. ^ During cold weather, the Tire Pressure Monitor (TPM) indicator light (a yellow horseshoe with an exclamation point) may illuminate. If this indicator turns off after the tires warm up (reach operating temperature), the tire pressure should be reset to placard pressure at the cold temperature. ^ The TPM system will work correctly with nitrogen in tires. ^ The TPM system is compatible with the GM Vehicle Care Tire Sealant but may not be with other commercially available sealants. Important: ^ Do not use the tire pressure indicated on the tire itself as a guide. Glass/Body - Windshield Wiper Performance Wiper Blade: Technical Service Bulletins Glass/Body - Windshield Wiper Performance INFORMATION Bulletin No.: 06-08-43-003C Date: February 21, 2011 Subject: Windshield Wiper Performance, Cleaning Instructions and Maintenance Models: 2012 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2010 and Prior Isuzu Medium Duty Trucks 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2011 and 2012 model year. Please discard Corporate Bulletin Number 06-08-43-003B (Section 08 - Body and Accessories). Wiper Concerns Most concerns about windshield wiper performance are the result of dirty wiper blades, damaged wiper blades, or worn out blades that are continuing to be used beyond their useful life. Depending on environmental conditions, wiper blades can have dramatic differences in lifespan. Here are some tips and guidelines to maximize wiper performance to avoid damage to the blades, and to avoid unnecessary replacements. Many wiper blades are being replaced under warranty with reviews showing there is nothing wrong with the returned blades other than a build-up of dirt. Additionally, advise the customer to review the information in their Owner Manual. Inspection and Cleaning Scheduled Maintenance - Inspect your wipers rubber blades every 4-6 months or 12,000 km (7,500 mi) for wear, cracking or contamination. - Clean the windshield and the rubber wiper blades (using the procedure below) if the blades are not clearing the glass satisfactorily. If this does not correct the problem, then replace the rubber elements. Cleaning Procedure Important Avoid getting windshield washer fluid on your hands. Wear rubber gloves or avoid direct contact with washer fluid. Important Do not use gasoline, kerosene, or petroleum based products to clean wiper blades. - Clean the rubber blades using a lint free cloth or paper towel soaked with windshield washer fluid or a mild detergent. You should see significant amounts of dirt being removed on the cloth. - Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road grime, sap and a buildup of car wash/wax treatments may additionally cause wiper streaking. Tip For a larger scale buildup on the windshield, use a non-abrasive cleaner such as Bon-Ami* (www.faultless.com) cleanser with a wet sponge, being sure to use plenty of water to avoid scratching the glass. Flush the surface and body panels completely. Tip For day-to-day exterior glass cleaning and to maintain a streak free appearance, suggest Vehicle Care Glass Cleaner, P/N 88862560 (in Canada, 992727). This product is an easy to use foaming cleaner that quickly removes dirt and grime from glass surfaces. Tip Interior glass should be cleaned with plain, clean water to eliminate any film or haze on the window and help prevent fogging, a major customer dissatisfier. Refer to Corporate Bulletin Number 03-00-89-006D for more information. The New Vehicle Pre-Delivery Inspection form also recommends using plain water to clean interior glass. *"We believe this material to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or any such items which may be available from other sources. Removal Brake Caliper: Service and Repair Removal For additional information see Removal Notes. See: Fundamentals and Basics 1. Siphon enough brake fluid out of the master cylinder to bring fluid level to 1/3 full to avoid fluid overflow when the caliper piston is pushed back into its bore. 2. Raise vehicle and remove front wheels. Fig. 2 Compressing piston & shoes with C-clamp 3. Using a C-clamp, push piston back into its bore. Fig. 3 Caliper & Mounting Bolts 4. Remove two mounting bolts and lift caliper away from disc. Hang caliper from coil spring with wire. CAUTION: Do not allow caliper to hang from brake hose. Page 3521 Intake Manifold Tuning Valve: Testing and Inspection Intake Manifold Tuning Valve Circuit Diagnosis Page 1752 Cylinder Head, Valve Guides & Valve Seats Page 5346 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Page 1924 Intake Manifold: Service and Repair 1. Disconnect battery ground cable. 2. Drain engine coolant from radiator, then remove plastic cover. 3. Disconnect engine wiring harness from throttle position sensor, idle air control motor, MAP sensor and communicator valve. 4. Disconnect throttle and T.V. linkage from upper intake manifold. 5. Remove ignition coil, then disconnect PCV hose from rear of upper intake manifold. 6. Disconnect vacuum hoses at front and rear of upper intake manifold. 7. Remove upper intake manifold bolts and studs. Mark location of bolts and studs for assembly reference. 8. Remove upper intake manifold. 9. Remove distributor and distributor wiring. Mark relationship of distributor housing and rotor for installation reference. 10. Remove upper radiator hose from thermostat housing, then the heater hose at lower intake manifold. 11. Disconnect fuel supply and return lines at rear of lower intake manifold. 12. Remove brace from lower intake manifold to A/C Compressor brace. 13. Disconnect engine wiring harness from fuel injector, EGR valve and coolant temperature sensor. 14. Remove lower intake manifold bolts, then the manifold from the vehicle. Fig. 8 Lower Intake Manifold Tightening Sequence Fig. 9 Upper Intake Manifold Tightening Sequence 15. Reverse procedure to install, noting the following: a. Apply RTV to the front and rear sealing surfaces on the block. b. Apply a 3/16 inch bead of RTV to the front and rear of the block, extend bead 1/2 inch up each cylinder head to seal and retain gaskets. c. Apply sealer part No. 1052080 or equivalent to lower intake manifold bolts. d. Torque lower intake manifold bolts to 35 ft. lbs. using tightening sequence shown in Fig. 8. e. Torque upper intake manifold bolts to 124 inch lbs. using tightening sequence shown in Fig. 9. Page 7433 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Electrical - Information For Electrical Ground Repair Grounding Point: Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Page 4551 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 422 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 1282 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 7912 AC Delco Service Centers Page 4114 Update your 1992 Service Manual Section 7 Transmission with the three (3) pages which are 7A-15a-6, 7A-15b-50 and 7A-15b-56. Page 2727 Valve Clearance: Adjustments VALVE ADJUSTMENT The VIN W engine does NOT have adjustable valve lash. When servicing the valve train requires removing and re-installing the rocker arms, tighten the rocker arm nuts to 27 Nm (20 ft. lbs.). Page 4870 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 4990 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 2029 needle bearing of the balance shaft. 4. To eliminate the possibility of the rear needle bearing rattling, a production running change was made in early May 1992, to a different type bearing. The needle bearing was changed to a journal type sleeve bearing (much like a camshaft bearing). This type bearing requires pressure fed oil, therefore, an engine block casting change was made to allow an oil passage to be drilled from the vertical oil gallery coming from the oil filter to the rear balance shaft journal. 5. If the detonation type rattle noise is unacceptable to the customer, the engine must be replaced using an SPO Goodwrench engine assembly part number 12520408. Important: Dealers are to retain all parts replaced for inspection in accordance with GM Service Policy and Procedures section 1.7.4 - Disposition of Defective material. Important: Replaced engine blocks are NOT to be provided to engine rebuilders. They should be returned as per instructions shipped with the replacement engine. 6. MEM-CAL information: When replacing a 1992 needle bearing engine (only produced prior to the May 1992 VIN break-points) with a sleeve bearing engine, the MEM-CAL must be updated to the later 1992 version. See part number information below. These new MEM-CALs are required to change the ESC calibration for the sleeve bearing engine. Without the correct calibration MEM-CAL, the engine will detonate. 7. ESO (Electronic Spark Control) information: The sleeve bearing engine "sounds" different to the ESO system. To make the sleeve bearing engine operate properly the 1992 M and L van vehicles, the knock sensors and locations have been changed. The 1992 M/L motors require only one 3900 ohm knock sensor mounted in the transmission flange close to the distributor. Connect the knock sensor harness to the knock sensor in the transmission flange. The second knock sensor connector harness at the middle of the right cylinder head will not be used on the 1992 model year M and L vans with the sleeve bearing engines. To ensure the harness does not lie on the exhaust manifold and short out, tie the connector back onto the harness using a plastic tie strap. The S and T trucks will continue using both 8200 ohm knock sensors with the sleeve bearing engine. No modification to the existing harness is necessary. Sleeve Bearing Balance Shaft Knock Sensor Information VIN Breakpoints for Sleeve Bearing Engines Beginning with: Page 2208 Fan Blade: Service Precautions Do not operate engine until fan has first been inspected for cracks and/or separations. If a fan blade is found to be bent or damaged in any way, do not attempt to repair or reuse damaged part. Proper balance is essential in fan assembly operation. Balance cannot be assured once a fan assembly has been found to be bent or damaged and failure may occur during operation, creating an extremely dangerous condition. Always replace damaged fan assembly. Page 3721 PROM - Programmable Read Only Memory: Application and ID Additional PROM Information New ECM PROMs for GM vehicles may be released for service at any time. The information in this system is accurate to the best of the publisher's knowledge and the publication date of the disk. Before ordering a PROM, consult with a GM parts and service dealer to verify the latest part number information. Scanner PROM ID information for earlier-model vehicles (1980-83) is less complete than for later models. To accurately identify PROM's in earlier vehicles, it may be necessary to check the external PROM code marked on the PROM. General Motors has often recommended that dealership technicians check the PROM history of a vehicle and install the most recent PROM revision before performing other diagnostic operations. Each succeeding PROM revision for a specific vehicle includes all previous revisions. Therefore, whenever you consider changing a PROM, review the entire PROM history to see if any revision covered the current driveability problem. Installing the most recent PROM revision may be impractical however for an independent service facility, particularly if the latest PROM revision does not address the specific driveability problem of the vehicle. Page 2643 Disclaimer Page 1701 Crankshaft: Specifications Bearing Clearance Bearing Clearance Main Bearings Production Front 0.0008-0.0020 in Intermediate 0.0011-0.0023 in Rear 0.0017-0.0032 in Service Front 0.0010-0.0015 in Intermediate 0.0010-0.0025 in Rear 0.0025-0.0035 in Connecting Rod Bearings Production 0.0013-0.0035 in Service 0.0020-0.0030 in Thrust Bearing 0.002-0.007 in Page 348 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 7353 Cruise Control Vacuum Vent Solenoid: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Radio Telephone/Mobile Radio - Install/Troubleshooting Technical Service Bulletin # 83-96-05 Date: 980701 Radio Telephone/Mobile Radio - Install/Troubleshooting File In Section: 9 - Accessories Bulletin No.: 83-96-05 Date: July, 1998 Subject: Radio Telephone/Mobile Radio (Transceiver) Installation and Troubleshooting Guidelines Models: 1990-99 Passenger Cars and Trucks This bulletin cancels and supercedes bulletin 34-92-12. Please discard Corporate Bulletin Number 34-92-12 (Section 9 - Accessories). The following information is being provided to assist in the installation and troubleshooting of Radio Telephone/Mobile Radios. Certain radio telephones or land mobile radios (also known as Radio Transceivers), or the way in which they are installed, may adversely affect various vehicle operations such as engine performance, driver information, entertainment and electrical systems. Expenses incurred to protect the vehicle systems from any adverse effect of any such installation are NOT the responsibility of General Motors Corporation. The following are general guidelines for installing a radio transceiver in General Motors vehicles. These guidelines are intended to supplement, but not to be used in place of, detailed instructions which are the sole responsibility of the manufacturer of the involved radio transceiver. Although this document refers to passenger vehicles, the same general guidelines apply to trucks. Page 5388 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7108 panel Antenna Tail lamps Door edge guards Metal wheel opening moldings *Roof marker lamps "Luggage rack *West coast style mirrors "Stripes Emblems/decals if necessary Swing out windows/seals Tail gate handle bezel S/T TRUCKS Windshield molding Bumper filler panels, Ft./Rr. Wiper arms Antenna Wheel opening moldings Cowl vent grille Door edge guards Side view mirrors Tail lamps *Wind deflector Rear Window (Jimmy) *Luggage rack *Stripes Emblems/decals if necessary Swing out windows/seals *Spare tire carrier and latch-external mount (Jimmy) M/L VANS Windshield molding Wheel opening moldings Headlamp bezels Antenna Tail lamps Door edge guards *Luggage rack *Stripes Emblems/decals if necessary R/V TRUCKS Wiper arms Cowl vent grille Antenna Tail lamps Hood ornaments Wheel opening moldings Side view mirrors Grille and headlamp bezels Door edge guards Bumper filler panel, Frt./Rr. Front side marker lamps *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary G VANS Service and Repair Evaporative Canister Filter: Service and Repair NOTE: NOT ALL EVAPORATIVE EMISSION CONTROL CANISTERS HAVE A SERVICEABLE FILTER. At intervals recommended, usually every 24 months or 30,000 miles, the filter on an open bottom canister should be replaced, 1. Remove all hoses from the top of the canister and mark. Remove the canister. 2. Remove the filter element by squeezing it out from under the lip surface at bottom of canister and from under retainer bar, where used. 3. Squeeze the new element under retainer bar, where used, and position it evenly around the entire bottom of the canister. Tuck the edges under the lip of canister. 4. Reinstall the canister to its original position on the vehicle, following normal service procedures. 5. Reconnect the hoses to the top of the canister, according to the labeling on top of canister. Page 5985 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Locations Transmission Position Switch/Sensor: Locations Park/Neutral Position Switch Assembly The Park/Neutral Position Switch is located on the steering column towards the firewall on top of the steering column shaft housing. Locations EGR Valve Position Sensor: Locations Engine Wiring, LH Side Wheels/Tires - Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Page 947 Distributor: Description and Operation Distributor Reference Signal PURPOSE The distributor reference signal provides the control module with both engine RPM and crankshaft position information. This enables the control module to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the control module receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the control module will not operate the injector. Page 3941 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Body - Vehicle Glass Distortion Information Back Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 6375 thread locking compound, such as Loctite(R) 242, should be used on each bolt of the saddle clamp to prevent the threads from loosening. Some vehicles produced during the second half of the 1993 model year will already have a factory installed HPCOS. Check the back of the compressor for this switch. If present, the above switch will not have to be added. 5. Evacuate the System, and Recharge with PAG or V5 Retrofit Oil and R-134a Newly designed low profile quick connect couplers for the ACR4, J 39500-20A and J 39500-24A, have been released. These should be installed before proceeding with the evacuation. See Step 3, and Figure 3. a. Connect the R-134a cart (ACR4) to the system. Open the coupler valves on the hoses so that the pressures can be read on the gauges. On the cart, open the HIGH SIDE VALVE ONLY. DO NOT OPEN THE LOW SIDE VALVE! Program the cart for a 15 minute evacuation. Important: If the vehicle has been at outside temperatures of less than 50° F (10° C), or at high altitudes (above 3000 ft), use a 30 minute evacuation to insure complete removal of the R-12. If the vacuum pump will not start and a "H-P" reading is indicated on the ACR4 display, loosen the fitting at the high side line connection to the ACR4 to relieve pressure in the line. Tighten the fitting after pressure has been relieved. DO NOT USE THE RECOVERY MODE TO RELIEVE LINE PRESSURE. b. Start the evacuation. For a proper evacuation, the cart must pull down to 28-29 in. Hg. at sea level (reduce by 1 in. for each 1000 ft above sea level). Check the low side gauge for proper vacuum level, to make sure the new fittings are operating properly. While the evacuation is being done, the Retrofit label can be filled out and installed (see Step 6). Important: If the compressor was replaced at the same time as this retrofit, and the new compressor was shipped with the correct amount of PAG oil already in it, DO NOT add any additional oil to the system! Go to Step D. If an "oil-less" compressor was installed, add oil in Step C. A new retrofit oil for use with V5 compressor vehicles has been released. This oil will be used ONLY for retrofitted vehicles in which the original V5 compressor is retained. IT WILL NOT BE USED IF A COMPRESSOR IS REPLACED AT THE TIME OF THE RETROFIT. Failure to use this oil may significantly shorten the useful life of the compressor. Important: If the V5 Retrofit oil is not available from GMSPO, the compressor MUST BE REPLACED! To summarize the correct retrofit oil usage: ^ Compressor replaced during retrofit - NO OIL ADDED if new compressor shipped with oil - 8 oz. of PAG oil (9 oz of PAG oil with V5 compressor) added if compressor shipped without oil ("oil-less" design) Diagram Information and Instructions Cigarette Lighter: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 2965 Oxygen Sensor Location Front Wheel Speed Sensor Wheel Speed Sensor: Service and Repair Front Wheel Speed Sensor 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Disconnect brake caliper assembly and position aside. 3. On two wheel drive models, remove hub and rotor assembly. 4. On four wheel drive models, remove rotor, then hub and bearing assembly. 5. On all models, disconnect wheel sensor electrical connector. 5. Remove sensor wire form upper control arm clip. 6. Remove sensor and splash shield assembly attaching bolts, then remove sensor. 7. Reverse procedure to install. On two wheel drive models, torque sensor and splash shield assembly to steering knuckle attaching bolts to 11 ft. lbs. Page 8610 Tools Tool Required: J-21104 Trim Pad Remover. REMOVE OR DISCONNECT 1. Door pillar molding. 2. Armrest. 3. Power window switch. 4. Trim panel. Pry the fasteners from their seats using J-21104. INSTALL OR CONNECT 1. Trim panel to the door. 2. Armrest. 3. Power window switch. 4. Door pillar molding. Page 3262 Fuel: Specifications ALCOHOL FUEL TYPES Methyl Tertiary-Butyl Ether (MTBE) Fuel containing Methyl Tertiary-butyl Ether (MTBE) may be used, providing there is no more than 15% alcohol by volume. Ethanol Fuel containing ethanol (ethyl) or grain alcohol may be used, providing there is no more than 10% ethanol alcohol by volume. Methanol Fuel containing methanol (methyl) or wood alcohol may be used, providing there is no more than 5% methanol by volume. Use of fuel (gasohol) that contains more than 5% methanol can corrode metal fuel system components and damage plastic and rubber parts. GASOLINE Unleaded gasoline must be used with a minimum octane rating of 87. Specifications Oil Pan: Specifications Oil Pan Bolts 8.3 ft.lb Oil Pan Nuts 16.5 ft.lb Oil Pan Studs To Oil Seal Retainer Or Crankcase 1-2 ft.lb Cruise Control - Works Intermittently Cruise Control Switch: All Technical Service Bulletins Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Page 7237 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 3096 Evaporative Emission Control Canister: Locations STD Engine Engine Compartment Components. LH Front Of Engine Compartment Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 Engine Page 429 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 8455 Brake Light Switch: Service and Repair Fig. 2 Stop Light Switch Installation 1. Disconnect battery ground cable. 2. Disconnect wiring connector from brake light switch located on brake pedal bracket. 3. Pull switch from mounting bracket. 4. Depress brake pedal, then push new switch into clip until shoulder bottoms out, Fig. 2. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed .53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Page 7479 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 643 MAP Circuit (VCM) VCM Circuit Page 7209 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 6331 Expansion (Orifice) Tube Tool Required: - J 26549-D Orifice Tube Remover and Installer or Equivalent REMOVE OR DISCONNECT 1. Discharge and recover refrigerant from the system. 2. Evaporator tube (5) from evaporator (10). 3. O-ring (11). 4. Expansion (orifice) tube. using J 26549-D. NOTE: In the event that difficulty Is encountered during the removal of a restricted or plugged expansion (orifice) tube. the following procedure is recommended: A. Remove as much of any impacted residue as possible. B. Carefully apply heat with heat gun (hair drier, epoxy drier or equivalent) approximately 7 mm (1/4 inch) from dimples on inlet pipe. Do not overheat pipe. NOTE: If the system has a pressure switch near the expansion tube location, it should be removed prior to hasting the pipe to avoid damage to switch. C. While applying heat, use expansion tube removal tools J 26549-D or equivalent to grip the expansion (orifice) tube. Use a turning motion along with a push-pull motion to loosen the impacted expansion (orifice) tube and remove it. INSTALL OR CONNECT Tool Required: - J 26549-D Orifice Tube Remover and Installer or Equivalent 1. Expansion (orifice) tube, using J 2654-D. IMPORTANT: Install the "shorter screen end" first into the evaporator. 2. New O-ring (11). 3. Evaporator tube (5) to evaporator (10). - Tighten evaporator tube (5) to 17 Nm (13 ft. lb.). 4. Refrigerant to the system. - Check the system for leaks. Page 6709 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Page 1241 Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. Note: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 8. Open the bleeder valve at least 3/4 of a turn and allow the fluid to flow until no air is seen in the fluid. Tighten the bleeder valve. 9. Repeat step 7 and 8 at each wheel cylinder/caliper until all the air is purged. 10. Disconnect the bleeder tank hose from the bleeder adaptor and remove the bleeder adaptor. 11. Fill the master cylinder to the proper level and replace lid. 12. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs. in.). 13. Remove the valve pressure bleeding tools J 39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 14. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. Important DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 15. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. Important DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 16. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs. in.). 17. Remove the bleeder adaptor, if using the pressure bleed procedure (Figure 1), and fill the master cylinder to the proper level with brake fluid. 18. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. Important MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 19. Repeat the entire brake bleed procedure if necessary. Page 3838 If clutch debris is found, it is also very important to inspect the Pressure Control (PC) solenoid valve (377) fluid screens. Clean or replace the PC solenoid (377) as necessary. It is also important to flush and flow check the transmission oil cooler using J45096. Refer to SI Automatic Transmission Oil Cooler Flushing and Flow Test for the procedure. The notches above each sprag must point up as shown when assembled into the outer race. Bearing Assembly, Input Sun Gear Snap Ring, Overrun Clutch Hub Retaining Hub, Overrun Clutch Wear Plate, Sprag Assembly Retainer and Race Assembly, Sprag Forward Sprag Assembly Retainer Rings, Sprag Assembly Outer Race, Forward Clutch Washer, Thrust (Input Carrier to Race) The following information applies when this sprag is used in 1982-86 transmissions. The new design sprag can be used on models 1982 through 1986, by replacing the entire assembly (637 - 644). Individual components are NOT Page 2563 Transmission Position Switch/Sensor: Testing and Inspection Park Neutral Switch Circuit Diagnosis Page 21 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Page 4776 Brake Proportioning/Combination Valve: Description and Operation These vehicles use either a two function or three function combination valve. Some vehicles use a height sensitive proportioning valve in addition to the combination valve. The two function combination valve consists of a metering valve and a brake failure warning switch. The hydraulic brake lines are routed through this valve to the wheel cylinders or calipers. The metering portion of this valve assists in providing balanced front to rear braking by delaying full hydraulic fluid pressure to the front disc brakes until the rear drum brakes overcome return spring tension and the linings contact the drums. The brake failure warning switch portion of the valve activates the brake warning lamp when there is a loss of pressure in either the front or the rear braking system. The three function combination valve consists of a metering valve, a brake failure warning switch, and a proportioning valve. The metering valve and brake failure warning switch operate the same as those in the two function combination valve previously described. The proportioning section of the valve proportions outlet pressure to the rear brakes after a certain rear input pressure has been reached, preventing rear wheel lock-up. The height sensitive proportioning valve provides ideal brake balance according to weight at rear axle. This valve is mounted on the frame and responds to changes in vehicle trim height in relation to rear axle load. Mechanical linkage connects the valve to a bracket attached to the rear axle. Page 4464 Park/Neutral Switch Circuit Description: The Park/Neutral (P/N) switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: - Idle Air Control (IAC) - Vehicle Speed Sensor (VSS) Diagnostics Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicated drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 2048 3. Balance shaft bearing retainer and bolts. Tighten Bolts to 14 Nm (120 in. lbs.). 4. Balance shaft driven gear and bolt. Tighten Bolt to 20 Nm (15 ft. lbs.) plus an additional 35 degrees. 5. Lifter retainer. - Rotate the balance shaft by hand to make sure there is clearance between the balance shaft and the lifter retainer. Replace the lifter retainer if necessary. 6. Turn the camshaft so, with the balance shaft drive gear temporarily installed, its timing mark is straight up. 7. With the balance shaft drive gear removed, turn the balance shaft so the timing mark on the driven gear points straight down. 8. Balance shaft drive gear onto the camshaft. Important - Be sure that the timing marks on the balance shaft drive gear and the driven gear line up dot to dot. 9. Balance shaft drive gear retaining stud. Tighten Stud to 16 Nm (12 ft. lbs.). 10. Intake manifold, as outlined in this section. 11. Camshaft sprocket and timing chain. Important: Line up the timing marks on the camshaft sprocket and crankshaft sprocket dot to dot (figure 41). When these marks are lined up dot to dot, the number four cylinder is at top dead center of its compression stroke. The distributor rotor will need to be positioned facing the number four terminal on the distributor cap when installed. 12. Camshaft sprocket bolts and nut. Tighten Bolts and nut to 28 Nm (21 ft. lbs.). 13. Distributor. 14. Distributor wiring. 15. Front cover and front cover bolts. Page 6973 Important: If the original pre-load torque value was < (less than) 3 lb.in., then reset torque specifications to 3-5 lb.in. Important: If the pinion seal and collapsible spacer are replaced, then refer to the appropriate Unit Repair Manual of pinion re-load specifications. 4. Install the "Dual Double Cardon" two piece propeller shaft and attaching bolts and nuts. 5. Apply a coating of GM P/N 12345382 Thread Lock or Loctite(R) # 242 or equivalent to the mounting bolt threads to flange. Tighten Tighten bolts to 50 Nm (37 lb.ft.). 6. Install the rear axle brake drum and wheel assemblies. 7. Add lubricant to the rear axle as necessary. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty. Page 6913 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 8225 Hazard Flashers With Digital Cluster Page 7718 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 3400 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Gauge: Customer Interest Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 63 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 2081 Disclaimer Testing and Inspection Temperature Warning Lamp/Indicator: Testing and Inspection A bi-metal temperature switch located in the cylinder head controls the operation of a temperature indicator light. If the engine cooling system is not functioning properly and/or coolant temperature exceeds a predetermined value, the warning light will illuminate. If the light is not lit when the engine is being cranked, check for a burned out bulb, an open in the light circuit, or a defective ignition switch. If the light is lit when the engine is running, check the wiring between light and switch for a ground, defective temperature switch, or overheated cooling system. As a test circuit to check whether the bulb is functioning properly, connect a wire from the ground terminal of the ignition switch to the temperature indicator light circuit. When the ignition is in the START (engine cranking) position, the ground terminal is grounded inside the switch and the bulb will be lit. When the engine is started and the ignition switch is in the ON position, the test circuit is opened and the bulb is then controlled by the temperature switch. Page 8108 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 2546 Oxygen Sensor: Service and Repair NOTE The Heated Oxygen Sensor (HO2S) uses a permanently attached pigtail and connector. This pigtail should not be removed from the Heated Oxygen Sensor (HO2S). Damage or removal of the pigtail or connector could affect proper operation of the oxygen sensor. Take care when handling the Heated Oxygen Sensor (HO2S). The in-line electrical connector and louvered end must be kept free of grease, dirt, or other contaminants. Also, avoid using cleaning solvents of any type. Do not drop or roughly handle the heated oxygen sensor. If the heated oxygen sensor pigtail wiring, connector or terminal is damaged, the entire oxygen sensor assembly must be replaced. Do not attempt to repair the wiring, connector or terminals. In order for the sensor to function properly, it must have provided to it a clean air reference. This clean air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors or terminals could result in the obstruction of the air reference and degraded oxygen sensor performance. CAUTION The following guidelines should be used when servicing the heated oxygen sensor: ^ Do not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor causing poor performance. Also, the sensor pigtail and harness wires must not be damaged in such a way that the wires inside are exposed. This could provide a path for foreign materials to enter the sensor and cause performance problems. ^ Neither the sensor or vehicle lead wires should be bent sharply or kinked. Sharp bends, kinks, etc., could block the reference air path through the lead wire. ^ Do not remove or defeat the oxygen sensor ground wire (where applicable). Vehicles that utilize the ground wired sensor may rely on this ground as the only ground contact to the sensor. Removal of the ground wire will also cause poor engine performance. ^ The Heated Oxygen Sensor (HO2S) may be difficult to remove, when engine temperature is below 48°C (120°F). Excessive force may damage threads in exhaust manifold or exhaust pipe. NOTE The engine harness may be repaired using Packard's Crimp and Splice Seals Terminal Repair Kit J 38125-A. Under no circumstances should repairs be soldered since this could result in the air reference being obstructed. Remove or Disconnect 1. Negative battery cable. 2. Electrical connector releasing locking tab. 3. Carefully back out oxygen sensor. Install or Connect NOTE A special anti-seize compound is used on the Heated Oxygen Sensor (HO2S) threads. The compound consists of liquid graphite and glass beads. The graphite will tend to burn away, but the glass beads will remain, making the sensor easier to remove. New, or service replacement sensors will already have the compound applied to the threads. If a sensor is removed from an engine, and if for any reason it is to be reinstalled, the threads must have anti-seize compound applied before reinstallation. 1. Coat threads of heated oxygen sensor with anti-seize compound (GM PIN 5613695 or equivalent), if necessary. 2. Sensor, and torque to 41 Nm (30 ib. ft.). 3. Electrical connector. 4. Negative battery cable. Recall 99V193000: ABS 4WD Switch Defective 4WD Switch: Recalls Recall 99V193000: ABS 4WD Switch Defective Description: Certain 4-wheel drive pickup trucks and sport utility vehicles equipped with ABS (antilock braking system) manufactured from September 1989 through August 1996. Under certain driving conditions the switch which signals the ABS system whether the vehicle is in 2-wheel or 4-wheel drive can malfunction causing increased stopping distances during ABS stops while in the two-wheel drive mode. If this occurred at a time when minimum stopping distance was required, a vehicle crash could occur without prior warning. Dealers will replace or repair the 4-wheel/2-wheel drive switch. The first phase of owner notification letters began May 31, 2000, with the last mailing completed by October 2000. Owners can contact Chevrolet at 1-800-222-1020 or GMC at 1-800-462-8782. Also contact the National Highway Traffic Safety Administration's Auto Safety Hotline at 1-888-DASH-2-DOT (1-888-327-4236). Page 4967 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Locations Engine Coolant Temperature (ECT) W Crankshaft Balancer - Removal/Installation Tool Harmonic Balancer - Crankshaft Pulley: Technical Service Bulletins Crankshaft Balancer Removal/Installation Tool File In Section: 6 - Engine Bulletin No.: 57-61-38 Date: January, 1996 SERVICE MANUAL UPDATE Subject: Section 6A - Engine Mechanical - Crankshaft Balancer Remover/Installer Tool Incorrectly Referenced Models: 1990-96 Chevrolet and GMC Truck S/T; M/L, C/K, P, G Models 1991-94 Oldsmobile Bravada 1996 Oldsmobile Bravada The crankshaft balancer remover/installer tool J 39046 listed in some 1990-96 service information sections 6A2, 6A3, 6A4, 6A5, 6A6, 6A7, 6A2B, 6A3B, 6A4B, 6A5B, and 6A6B is incorrectly referenced. The correct tool number for the truck models listed above is J 23523-F or equivalent. Page 6388 accumulator. The system will operate properly as long as refrigerant charge amounts are strictly adhered to. 6. Refrigerant Charge Level The retrofit R-134a charge level is more critical than with R-12 systems. Overcharging may push the mineral oil out of the AID, and cause it to circulate as a liquid. This is more likely to result in compressor damage. Undercharging may lead to loss of performance. It is very important to clear the hoses during the charging operation, to insure that all the refrigerant is delivered to the vehicle A/C system. This is covered in Step 6D of the Retrofit Procedure. C. Parts Information Page 8364 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 6954 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Page 5299 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 5423 Symbol Identification Recall 96V195000: Steering Shaft Loosening Steering Shaft: Recalls Recall 96V195000: Steering Shaft Loosening The intermediate steering shaft loosens at the steering shaft to steering gear coupling. With this looseness, the yoke pinch bolt can wear on the splines of the shaft until there is no longer an interference between the splines and the bolt. This condition can cause body to chassis movement allowing the steering shaft to separate from the steering gear which can result in a loss of steering control. Dealers will retorque the upper and lower bolts to correct specifications. Vehicle Description: Postal vehicles only. Owner Notification: Owner notification is expected to begin during late October 1996. NOTE: Owners who take their vehicles to an authorized dealer on an agreed upon service date and do not receive the free remedy within a reasonable time should contact Chevrolet at 1-800-222-1020. Also contact the National Highway Traffic Safety Administrations Auto Safety Hotline at 1-800-424-9393. 1987 CHEVROLET TRUCK S10 1988 CHEVROLET TRUCK S10 1989 CHEVROLET TRUCK S10 1990 CHEVROLET TRUCK S10 1991 CHEVROLET TRUCK S10 1992 CHEVROLET TRUCK S10 1993 CHEVROLET TRUCK S10 1994 CHEVROLET TRUCK S10 1995 CHEVROLET TRUCK S10 Page 4584 Figure 7 Figure 8 Figure 9 Figure 10 Page 7312 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Tires - Slipping on Rim Tires: Customer Interest Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Symptom Related Diagnostic Procedures Steering Gear: Symptom Related Diagnostic Procedures Fig. 1 Troubleshooting power steering system Page 7400 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 761 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 179 ECM Connector C2 Page 2128 2.8L - Engine Distributor Components DELCO REMY DISTRIBUTORS Distributors with separate coils are used on light duty truck engines. The ignition coil connects to the distributor cap through a high tension wire. The distributor uses an internal magnetic pickup assembly that consists of a permanent magnet, pole piece with internal teeth, and pickup coil. When the rotating teeth of the timer core line up with the teeth of the pole piece, voltage is induced in the pickup coil. This voltage signals the ignition control module to trigger the primary ignition circuit. Current flow in the primary circuit is interrupted and a high voltage of up to 35,000 volts is induced in the ignition coil secondary winding. This high voltage is directed through the secondary ignition circuit to fire the spark plugs. The distributor used on the 2.8L engine uses a capacitor for radio noise suppression that is integral with the terminal block. IDENTIFICATION The part number (seven digits) is located on a label on the distributor cap. IGNITION CONTROL MODULE The ignition control module is a solid state unit containing many complete circuits. The circuits control spark triggering, switching, current limiting, dwell control, and distributor pickup. The vehicle's computer sends signals to the module to control dwell and spark timing. The module may have seven or eight terminals, depending on the ignition system. POLE PIECE AND COIL ASSEMBLY The pole piece and plate assembly (often referred to as the pickup coil assembly) located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. CAPACITOR The capacitor in the distributor is for radio noise suppression. Page 2554 Throttle Position Sensor: Mechanical Specifications Throttle Position Sensor 18 in.lb Page 7389 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 6353 Hose/Line HVAC: Vehicle Damage Warnings Handling of Refrigerant Lines and Fittings Pipe And Hose Connections Torque All metal tubing lines should be free of dents or kinks to prevent loss of system capacity due to line restriction. - The flexible hose lines should never be bent to a radius of less than four (4) times the diameter of the hose. - The flexible hose lines should never be allowed to come within a distance of 63.5 mm (2-1/2 inches) of the exhaust manifold. - Flexible hose lines should be inspected regularly for leaks or brittleness and replaced with new lines if deterioration or leaking is found. - When disconnecting any fitting in the refrigerant System, the system must be discharged of all Refrigerant-12. However, proceed very cautiously, regardless of the gage readings. Open very slowly, keeping your face and hands away so that no injury can occur. If pressure is noticed when a fitting is loosened, allow it to bleed off very slowly. - If any refrigerant line is opened to the atmosphere, it should be immediately capped to prevent the entrance of moisture and dirt, which can cause internal compressor wear or plugged lines, in the condenser and evaporator core and expansion (orifice) tubes or compressor inlet screens. - The use of the proper wrenches when making connections on O-ring fittings, is important. The use of improper wrenches may damage the connection. The opposing fitting should always be backed up with a wrench to prevent distortion of connecting lines or components. When connecting the flexible hose connections, it is important that the swaged fitting and the flare nut. as well as the coupling to which it is attached, be held at the same time using three different wrenches to prevent turning the fitting and damaging the seat. - The O-rings and seats must be in perfect condition. The slightest burr or piece or piece of dirt may cause a leak. When replacing the O-ring, first dip it in clean 525 viscosity refrigeration oil. - Tighten tubing connections to the specified torque, refer to accompanying figure. Maintaining Chemical Stability The life and efficient operation of the air conditioning system depends on the chemical stability of the refrigeration system. When foreign materials, such as dirt, air or moisture, contaminate the refrigeration system, they change the stability of the R-12 and 525 viscosity compressor oil. They will also affect the pressure-temperature relationship and reduce efficiency, and could cause internal corrosion and abnormal wear of moving parts. The following general practices should be followed to insure chemical stability in the system: 1. Whenever it becomes necessary to disconnect a hose connection, wipe away any dirt or oil at and near the connection to eliminate the possibility of dirt entering the system. Both sides of the connection should be capped, plugged or taped as soon as possible to prevent the entrance of dirt and moisture. (It must be remembered that all air contains moisture. Air that enters any part of the refrigeration system will carry moisture with it and the exposed surfaces will collect the moisture quickly.) 2. Keep tools clean and dry. This includes the Manifold Gage Set and all replacement parts. 3. When adding 525 viscosity refrigerant oil, the container/transfer tube through which the oil will flow should be exceptionally clean and dry due to the fact that refrigerant oil should be as moisture-free as possible. 4. When it is necessary to "open" an A/C system, have everything needed ready so that as little time as possible will be required to perform the operation. Do not leave the A/C system open any longer than necessary. Page 6251 Compressor Shaft Seal - Seals should not be re-used. Always use a new specification service seal kit. Be sure that the seal to be installed is not scratched or damaged in any way. Make sure that the seal is free of lint and dirt that could damage the seal surface or prevent sealing. Install or Connect 1. Dip the new seal O-ring in clean 525 viscosity refrigerant oil and assemble onto O-ring installer J 33011. 2. Insert the O-ring installer J 33011 into the compressor neck until the installer "bottoms." Lower the moveable slide of the O-ring installer to release the O-ring into the seal O-ring lower groove. (The compressor neck top groove is for the shaft seal retainer ring.) Rotate the installer to seat the O-ring and remove the installer. Lip Seal Installed On Seal Protector 3. Attach the seal to the seal remover and installer J 23128-A and dip the seal in clean 525 viscosity refrigerant oil to coat the seal. Install seal protector J 34614 in the seal, place over shaft and push seal in place with a rotary motion. 4. Install the new seal retainer ring with its flat side against the seal, using snap-ring pliers J 5403. Use the sleeve from O-ring installer J 33011 to press in on the seal retainer ring so that it snaps into its groove. 5. To leak test, install compressor leak test fixture J 9625-A on rear head of compressor and connect gage charging lines using J 38100-C Refrigerant Recovery System. Pressurize suction and high-side of compressor with Refrigerant 12 vapor to drum pressure. Temporarily install the shaft nut and, with the compressor in horizontal position. rotate the compressor shaft in normal direction of rotation several turns by hand. Leak test the seal area and correct any leak found. Recover refrigerant. Remove shaft nut. 6. Remove any excess oil resulting from installing the new seal parts from the shaft and inside the compressor neck. 7. Install the clutch plate and hub assembly as described in minor repair procedures. 8. Reinstall the compressor, belt and tighten bracket. 9. Evacuate and charge the refrigerant system. Locations Engine Wiring, LH Side Page 3266 Fuel Filler Cap: Description and Operation The fuel tank filler neck is equipped with a screw-type cap. The threaded part of the cap requires several turns counterclockwise to remove. The long threaded area was designed to allow any remaining fuel tank pressure to escape, while the cap was being removed. A built-in torque-limiting device prevents overtightening. To install, turn the cap clockwise until a clicking noise is heard. This signals that the correct torque has been reached and the cap is fully seated. Page 5424 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 140 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 5290 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Page 5438 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 1633 Rocker Arm Assembly: Service and Repair Rocker Arms & Pushrods Replace 1. Disconnect battery ground cable. 2. Remove air cleaner assembly, then the emission relays and bracket. 3. Remove wiring harnesses and spark plug wires from clips and position aside. 4. Disconnect dipstick tube from cylinder head and position tube aside. 5. Remove rocker arm cover. 6. Remove rocker arm nut, then rocker arm and ball. 7. Remove pushrod. 8. Reverse procedure to install. Adjust valves as described under ADJUSTMENT PROCEDURES/VALVES. Page 7637 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 7996 Turn And Hazard Lamp Flashers Page 5222 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 6040 Wheel Fastener: Specifications Wheel Fastener Tightening Sequence Lug Nut Torque Patterns IMPORTANT Check all parts, including rims, lug studs, lug nuts, and mating surfaces of hubs and tire rims for rust, damage, or dirt. Clean mating surfaces with a wire brush to remove any foreign material. Replace any damaged parts as needed. Careless installation of tire/rim assemblies in a vehicle is a major cause of tire installation problems. Proper installation, including fastener torque, is essential to economical, safe and trouble free service. Use only the proper sizes and types of fasteners for safe and proper service. Tighten the fasteners a quarter turn at a time using the tightening sequence diagram as a guide. This is very important to prevent misalignment of the wheel. Continue tightening the fasteners in sequence until the fasteners are tightened to the proper torque (See WHEEL FASTENER TORQUE). CAUTION: Improper torque or tightening sequence can cause distortion, fatigue cracks, or alignment problems. After driving the vehicle for a short distance, recheck the wheel fastener torque. Parts will usually seat naturally, reducing the torque on the fasteners. Retorque all fasteners to the proper torque. Page 6686 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 8261 License Plate Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 7376 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 3569 Spark Plug Wire: Description and Operation CONSTRUCTION The spark plug/coil secondary wiring is a carbon impregnated cord conductor encased in a rubber jacket. The 7-mm wire used on the 2.5L and 2.8L engines and the 8-mm wire used on the 3.1L, 4.3L, 5.0L, 5.7L and 7.4L has an outer layer of silicone. The silicone jacket withstands very high temperature and also provides an excellent insulator for the higher voltage of the electronic ignition system. The silicone spark plug boots form a tight seal on the plugs and distributor cap. CAUTION - Care should be exercised when connecting a timing light or other pick-up equipment. - Do not force anything between the boot and wiring. - Do not pierce the secondary wire insulation. - Use only equipment with an inductive pickup to check for spark plug firing. - Do NOT pull on the wire to remove. The boot should be twisted 1/2 turn before removing. Pull on the boot, or use a tool designed for this purpose. Page 7430 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 1150 Make sure the vehicle compressor is engaged. Turn the cart on and start the recovery cycle. OPEN ONLY THE HIGH SIDE VALVE ON THE GAUGE SET. The vehicle system should eventually shut the compressor off. If the low side pressure drops below 15 psi, and the compressor does not turn off, turn it off now (go to "VENT" or "ECON" mode), but leave the engine running and the blower on "high". c. After the recovery cart shuts off the first time, wait 5 minutes. If the pressure on either the high or the low side rises above 0 psi, restart the recovery process. After the second shutoff, wait 2 minutes. If the pressure again rises above 0 psi, restart, and after shutoff, again wait 2 minutes. The process can be stopped when the pressure does not rise above 0 psi after 2 minutes. The engine can be shut off at this time. d. Remove the R-12 reclaim hose and the gauge set from the vehicle. Any repairs needed should be done at this time. If any components other than the compressor are replaced, they should be installed dry, and no extra oil should be added. 3. Install the Service Port Conversion Fittings Important: For GEO vehicles, skip to Step 4. Fitting installation is covered in that step. For vehicles that require a HPCOS, see Step 4. Some of these vehicles use a specific combination fitting to mount the HPCOS, which includes the high side service port fitting and the HPCOS port. The low side fitting is installed as detailed below. See "Platform Details" for further information. Important: A new tool kit, P/N J 39500-250, has been released. This kit contains the following items: ^ J 39500-71 Oil Injection Bottle Conversion Kit (includes 3 12 oz bottles, an extender tube, caps, and fittings) ^ J 39500-275 Tool kit, including the following: (See Figure 2) - J 34611-A Double ended valve core remover - J 25498-A High side adapter fitting - J 38702 Deep valve core adapter fitting Page 771 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. A/T - No Movement in Drive or 3rd Gear Clutch: Customer Interest A/T - No Movement in Drive or 3rd Gear TECHNICAL Bulletin No.: 08-07-30-027 Date: June 04, 2008 Subject: No Movement When Transmission is Shifted to Drive or Third - Normal Operation When Shifted to Second, First or Reverse (Replace Forward Sprag Assembly) Models: 1982 - 2005 GM Passenger Cars and Light Duty Trucks 2006 - 2007 Buick Rainier 2006 Cadillac Escalade, Escalade ESV, Escalade EXT 2006 Chevrolet SSR 2006 - 2008 Chevrolet Avalanche, Colorado, Express, Silverado Classic, Silverado, Suburban, Tahoe, TrailBlazer 2006 GMC Yukon Denali, Yukon Denali XL 2006 - 2008 GMC Canyon, Envoy, Savana, Sierra Classic, Sierra, Yukon, Yukon XL 2006 Pontiac GTO 2006 - 2007 HUMMER H2 2006 - 2008 HUMMER H3 2006 - 2008 Saab 9-7X with 4L60, 4L60E, 4L65E or 4L70E Automatic Transmission (RPOs MD8, M30, M32, M33 or M70) Condition Some customers may comment that the vehicle has no movement when the transmission is shifted to DRIVE or THIRD position, but there is normal operation when it is shifted to SECOND, FIRST or REVERSE position. Cause This condition may be caused by a damaged forward sprag assembly (642). Correction When inspecting the sprag, it is important to test the sprag for proper operation by holding the outer race (644) with one hand while rotating the input sun gear (640) with the other hand. The sun gear should rotate only in the counterclockwise direction with the input sun gear facing upward. If the sprag rotates in both directions or will not rotate in either direction, the sprag elements should be inspected by removing one of the sprag assembly retaining rings (643). Refer to SI Unit Repair section for forward clutch sprag disassembly procedures. If the sprag is found to be damaged, make repairs to the transmission as necessary. A new forward roller clutch sprag assembly is now available from GMSPO. Page 7461 Figure 7 Figure 8 Figure 9 Figure 10 Page 5105 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Locations Fuel Filler Neck Page 2543 Oxygen Sensor: Description and Operation Exhaust Oxygen Sensor (02) PURPOSE The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315°C (600°F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Oxygen Sensor Output Voltage vs. Air/Fuel Ratio The difference in oxygen concentration in the narrow range of optimum air/fuel ratio causes a large voltage change that is easily measured. OPERATION A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. Page 8546 Junction Block Wiring Engine - High Oil Pressure Reading at Start-Up Oil Pressure Gauge: Customer Interest Engine - High Oil Pressure Reading at Start-Up Number: 93-60-6A Section: 6A Date: NOV. 1992 Corporate Bulletin No.: 268306 ASE No.: A1, A8 Subject: HIGH OIL PRESSURE READING AT START-UP Model and Year: 1992-93 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L, AND 5.7L ENGINES Some 1992 and 1993 Chevrolet Light Duty Trucks with oil pressure gauges built after 6/15/92 may exhibit high oil pressure readings at start up, especially when cold. Engines produced after 6/15/92 were built with an enhanced oil pump capable of producing approximately 10 psi more pressure than the previous pump. This may cause the gauge to temporarily read as high as 60 psi during start up. The length of time the oil pressure stays high will depend on oil viscosity, engine temperature, and ambient temperature. This condition will not cause any ill effects on the engine or gauge and unless there are other symptoms to indicate an oil pressure or gauge problem such as very low pressure after warm up, rapid fluctuation, engine noise etc. no repairs should be attempted. Replacing the oil pump or gauge system parts will not be effective. Build date of the engine can be verified by the engine code. The location of this code is illustrated in section OA of the appropriate service manual. The engine code is 8 positions long with an alpha plant designator in the first position, followed in the next four positions by the month and day; for example T0615xxx would indicate that this engine was built in Tonawanda on June 15th and, therefore, has the enhanced oil pump. The plant code is insignificant because all 4.3L, 5.0L, and 5.7L plants began using the enhanced oil pump on the same day. Locations Engine Wiring, LH Side Page 6750 Figure 7 Figure 8 Figure 9 Figure 10 Page 3728 PROM - Programmable Read Only Memory: Application and ID Reading Technical Service Bulletins Always read any Technical Service Bulletins (TSB's) referenced before replacing a PROM. Service bulletins list parts that must be installed when a PROM is changed, and provide information on trouble codes, troubleshooting and driveability problems for which the PROM was released. To find applicable TSB's: Complete TSB Listing 1. Hold down right mouse button and select "Vehicle" in the "Pull Right Menu". 2. Select the TSB ICON. 3. Select "All Technical Service Bulletins by Number, Date, and Title". 4. Select "Sort by Number", "Sort by Date", or "Sort by Title". 5. Scroll up or down to find the desired TSB. PROM TSB Listing Only 1. Hold down right mouse button and select "Technical Service Bulletins" in the "Pull Right Menu". 2. Select "All Technical Service Bulletins for PROM - Programmable Read Only Memory". 3. Select "Sort by Number", "Sort by Date", or "Sort by Title". 4. Scroll up or down to find the desired TSB. Page 2151 Valve Clearance: Adjustments VALVE ADJUSTMENT The VIN W engine does NOT have adjustable valve lash. When servicing the valve train requires removing and re-installing the rocker arms, tighten the rocker arm nuts to 27 Nm (20 ft. lbs.). Locations CMFI Intake Manifold Sensors/Valves Page 5376 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 6371 Make sure the vehicle compressor is engaged. Turn the cart on and start the recovery cycle. OPEN ONLY THE HIGH SIDE VALVE ON THE GAUGE SET. The vehicle system should eventually shut the compressor off. If the low side pressure drops below 15 psi, and the compressor does not turn off, turn it off now (go to "VENT" or "ECON" mode), but leave the engine running and the blower on "high". c. After the recovery cart shuts off the first time, wait 5 minutes. If the pressure on either the high or the low side rises above 0 psi, restart the recovery process. After the second shutoff, wait 2 minutes. If the pressure again rises above 0 psi, restart, and after shutoff, again wait 2 minutes. The process can be stopped when the pressure does not rise above 0 psi after 2 minutes. The engine can be shut off at this time. d. Remove the R-12 reclaim hose and the gauge set from the vehicle. Any repairs needed should be done at this time. If any components other than the compressor are replaced, they should be installed dry, and no extra oil should be added. 3. Install the Service Port Conversion Fittings Important: For GEO vehicles, skip to Step 4. Fitting installation is covered in that step. For vehicles that require a HPCOS, see Step 4. Some of these vehicles use a specific combination fitting to mount the HPCOS, which includes the high side service port fitting and the HPCOS port. The low side fitting is installed as detailed below. See "Platform Details" for further information. Important: A new tool kit, P/N J 39500-250, has been released. This kit contains the following items: ^ J 39500-71 Oil Injection Bottle Conversion Kit (includes 3 12 oz bottles, an extender tube, caps, and fittings) ^ J 39500-275 Tool kit, including the following: (See Figure 2) - J 34611-A Double ended valve core remover - J 25498-A High side adapter fitting - J 38702 Deep valve core adapter fitting Page 6559 b. Locate the transceiver for remote radios on the driver's side of trunk as near to the vehicle body side as possible (See Figure 2 - Trunk Mount Transceiver Installation). Caution: To avoid possible serious injury, do not mount any transceivers, microphones, speakers, or any other item In the deployment path of a Supplemental Inflatable Restraint (SIR) or "Air Bag". 2. Antenna Installation a. Each vehicle model reacts to radio frequency energy differently. It is suggested that a magnetic-mount antenna be used to check the proposed antenna location for unwanted effects on the vehicle. Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 4878 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 1777 Drive Belt: Service and Repair Fig. 20 Serpentine Drive Belt Routing 1. Remove belt tensioner pulley retaining bolt. 2. Remove belt tensioner pulley. then the belt. 3. Reverse procedure to install, refer to Fig. 20 for belt routing. Page 5130 Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode wire ends to protect the diode from excess heat. Follow the manufacturers instructions for the solderin equipment you are using. 5. Install terminal(s) into the connector body if previously removed in step number 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion completely cover all exposed wire and diode attachment points. NOTE: A universal diode with a 3 amp, 400 PIV (Peak Inverse Voltage) rating can be used in all of the previously mentioned applications. The following 1993 Service Manuals will need to be updated with the correct part numbers and rating changes. Carline Page All J, L, W, and UO 8A-5-12 Heat sink, part number 276-1567, can be obtained from Radio Shack. We believe the diodes and heat sink listed in this article as well as their manufacturer to be reliable. There may be additional manufacturers or equivalent products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. Page 5702 Ball Joint: Testing and Inspection Lower Fig. 20 Lower Ball Joint Wear Indicator. 4 X 2 Models BRAVADA, TYPHOON & 4X2 MODELS The lower ball joint has a visual wear indicator, Fig. 20. To check, vehicle weight must rest on wheels to properly load ball joints. Fig. 21 Checking Ball Joints. 4 X 4 Models 4X4 MODELS EXCEPT BRAVADA & TYPHOON Refer to Fig. 21 for ball joint inspection procedure on 4 x 4 vehicles. Specifications Manifold Pressure/Vacuum Sensor: Specifications Voltage 3.6 to 5.2 V at 1000 to 2000 ft 3.5 to 5.1 V at 2000 to 3000 ft 3.3 to 5.0 V at 3000 to 4000 ft 3.2 to 4.8 V at 4000 to 5000 ft 3.0 to 4.6 V at 5000 to 6000 ft 2.9 to 4.5 V at 6000 to 7000 ft 2.8 to 4.3 V at 7000 to 8000 ft 2.6 to 4.2 V at 8000 to 9000 ft 2.5 to 4.0 V at 9000 to 10000 ft Page 6561 Connect the negative lead to the battery body connection point (usually identified by a short # 10 AWG or larger wire running from the negative battery terminal to the body of the vehicle). Important: See above important statement regarding fusing the negative power lead. 4. Connect the positive and negative leads to the Special Equipment Option (SEO) wiring provided for this purpose (if vehicle has this option). b. For One Piece Transceivers (See Figure 1 - One Piece Transceiver Installation) When ignition switch control is desired, and no SEO wiring exists, a 12 volt power contactor must be installed in the transceiver positive power lead (See Figure 3 - Power Contactor Wiring). The contactor (supplied by the installer) should be located near a proper 12 volt feed source. One lead of the contactor coil should be connected through an appropriate in-line fuse to an available accessory circuit or ignition circuit not Page 2432 Engine Control Module: Description and Operation Powertrain Control Module (PCM) PURPOSE The Control Module is the control center of the fuel injection system. It constantly looks at the information from various sensors (inputs) and controls the systems (outputs) that affect vehicle performance. The control module also performs the diagnostic control moduletion of the system. It can recognize operational problems, alert the driver through the Malfunction Indicator Lamp (MIL) "Service Engine Soon" light on the instrument panel and store a Diagnostic Trouble Code(s) (DTC) in the control module memory. The DTC identifies the problem areas to aid the technician in performing repairs. OPERATION The control module is an electronic computer designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The control module can control these devices through the use of Quad Driver Modules (QDM). When the control module is commanding a device or a component "ON," the voltage potential of the output is "LOW" or near zero volts. When the control module is commanding a device or component "OFF," the voltage potential of the circuit will be "HIGH," or near 12 volts. The primary function of the QDM is to supply the ground for the component being controlled. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The control module has two parts for service: - Controller which is the control module without the PROM (MEM-CAL). - PROM (Programmable Read Only Memory) which is a separate memory calibrator unit Learning Ability The control module has a "learning" ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected, to clear diagnostic trouble codes or for other repairs. the "learning" process resets and begins again. A change may be noted in the vehicle's performance. To "teach" the vehicle, ensure the engine is at operating temperature. The vehicle should be driven at part throttle, with moderate acceleration and idle conditions until normal performance returns. NOTE The control module must be maintained at a temperature below 85°C (185°F) at all times. This is most essential if the vehicle is put through a baking process. The control module will become inoperative if it's temperature exceeds 85°C (185°F). It is recommended that temporary insulation be placed around the control module during the time the vehicle is in a paint oven or other high temperature processes. Electrical - Information For Electrical Ground Repair Grounding Point: Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Page 3905 All 2006 and future model transmissions that use DEXRON(R)-VI are to be serviced ONLY with DEXRON(R)-VI fluid. DEXRON(R)-VI is an improvement over DEXRON(R)-III in the following areas: * These ATF change intervals remain the same as DEXRON(R)-III for the time being. 2006-2008 Transmission Fill and Cooler Flushing Some new applications of the 6L80 six speed transmission will require the use of the J 45096 Flushing and Flow Tester to accomplish transmission fluid fill. The clean oil reservoir of the machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI. Parts Information Disclaimer Page 5182 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Hydraulic System Bleeding Brake Bleeding: Service and Repair Hydraulic System Bleeding Manual Bleeding 1. If vehicle is equipped with power brakes, remove vacuum reserve by applying brakes several times with engine off. 2. Fill master cylinder reservoirs with suitable brake fluid. Be sure to always keep master cylinder reservoirs at least half full during entire bleeding procedure. 3. If master cylinder is suspected to have air in the bore, it must be bled first, as follows: a. Disconnect forward brake pipe connection at master cylinder. b. Allow brake fluid to fill master cylinder bore until it begins to flow from forward pipe connector port. c. Connect and tighten forward brake pipe at master cylinder. d. Depress brake pedal slowly one time and hold, then loosen forward brake pipe connection at master cylinder to purge air from bore. Tighten connection, then release brake pedal slowly. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged from bore. e. Bleed rear bore of master cylinder as front bore was bled. 4. Bleed right rear brake as follows: a. Depress brake pedal slowly one time and hold. b. Loosen bleeder valve to purge air from brake, then tighten bleeder valve and slowly release pedal. c. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged. 5. Bleed left rear, right front, and left front brakes, in that order, using same method as for right rear brake. 6. Check brake operation and ensure pedal is firm. Also check master cylinder fluid level and add fluid as necessary. 7. Turn off brake warning light by applying moderate pressure to brake pedal several times. 8. Road test vehicle. Fig. 1 Installing Pressure Bleeder Adapter Pressure Bleeding 1. Loosen, then slightly retighten bleeder valves at all four wheels. Repair any broken, stripped or frozen valves at this time. 2. Using a diaphragm type pressure bleeder, install suitable bleeder adapter to master cylinder, Fig. 1. 3. Charge bleeder ball to 20-25 psi, then depress and hold valve stem on combination valve. 4. Connect pressure bleeder line to adapter. 5. Open line valve on pressure bleeder, then depress bleed-off valve on adapter until a small amount of brake fluid is released. 6. Raise and support vehicle. 7. Bleed right rear, left rear, right front and left front brakes, in that order. 8. Place transparent tube over bleeder valve, then allow tube to hang down into transparent container. Ensure end of tube is submerged in clean brake fluid. 9. Open bleeder valve 1/2 to 3/4 turn and allow fluid to flow into container until all air is purged from line. Flushing Hydraulic System If brake fluid is old, rusty or contaminated, or whenever new parts are installed in the hydraulic system, the system must be flushed. Bleed brakes, allowing at least one quart of clean brake fluid to pass through system. Any rubber parts in hydraulic system which were exposed to contaminated fluid must be replaced. Page 7101 panel(s) that can be used as a starting/ stopping point when making a repair. Clearcoat: A clear topcoat required to cover a color basecoat. DELAMINATION: Loss of adhesion between one coat of paint to succeeding coats or coatings. Ultraviolet DELAMINATION is between the E coat (ELPO) and color topcoat(s). ELPO: (Electrocoating or "E" coat): The process by which electrically charged primer is plated on conductive surfaces of an opposite charge. This process provides outstanding corrosion resistance. Guidecoat: A light coat (almost overspray) of color applied over primer surfacer prior to wetsanding to highlight any low spots. Insert Color: The secondary two-tone color between the break line and body side molding. Monocoat: A color topcoat that does not require a clearcoat. Primer: The coating applied to a properly prepared substrate (bare metal) to give adhesion, corrosion and chemical resistance. Primer Sealer: An undercoat that provides maximum adhesion. color coating and corrosion protection. Primer Surfacer: An undercoat used to fill imperfections, with primer qualities, that must be sanded. Refinish: The act of replacing a painted surface, usually undercoat and topcoat. Scuff Sand: A method of sanding a painted surface using a fine grit sandpaper to promote paint adhesion. Topcoat: A finish material over an undercoat material. Ultraviolet Light: The portion of the spectrum of light which can cause fading of paint. It is located below the visible part of the spectrum. V.O.C.: "Volatile Organic Compound" or "Volatile Organic Content" relates to certain emission requirements in specific areas of the country. Technical Service Bulletin # 923310 Date: 911101 Paint - Acid Rain Damage to Base Coat/Clear Coat Page 545 Stoplamp Switch Installation Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Tires - Slipping on Rim Tires: All Technical Service Bulletins Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Page 3520 LH Front Side Of Engine PURPOSE The tuning valve (rotary solenoid device) is electrically controlled by the ECM based on RPM and TP signal inputs, for accurate switching capability at optimum switching points to enable either a "split" or "single" plenum condition OPERATION During the low and high end of the RPM range, the ECM de-energize 5 the valve and creates a "split" plenum condition that provides for peak torque along with increased peak horsepower. During the mid RPM range, the ECM energizes the valve, thus creating a "single" tuning plenum condition that provides for mid RPM range peak torque. CONSTRUCTION The Intake Manifold Tuning assembly consists of: - ECM - Intake Manifold Tuning Valve Relay - Intake Manifold Tuning Valve Solenoid (Assembly) - Upper and Lower Intake Manifolds Page 6425 thread locking compound, such as Loctite(R) 242, should be used on each bolt of the saddle clamp to prevent the threads from loosening. Some vehicles produced during the second half of the 1993 model year will already have a factory installed HPCOS. Check the back of the compressor for this switch. If present, the above switch will not have to be added. 5. Evacuate the System, and Recharge with PAG or V5 Retrofit Oil and R-134a Newly designed low profile quick connect couplers for the ACR4, J 39500-20A and J 39500-24A, have been released. These should be installed before proceeding with the evacuation. See Step 3, and Figure 3. a. Connect the R-134a cart (ACR4) to the system. Open the coupler valves on the hoses so that the pressures can be read on the gauges. On the cart, open the HIGH SIDE VALVE ONLY. DO NOT OPEN THE LOW SIDE VALVE! Program the cart for a 15 minute evacuation. Important: If the vehicle has been at outside temperatures of less than 50° F (10° C), or at high altitudes (above 3000 ft), use a 30 minute evacuation to insure complete removal of the R-12. If the vacuum pump will not start and a "H-P" reading is indicated on the ACR4 display, loosen the fitting at the high side line connection to the ACR4 to relieve pressure in the line. Tighten the fitting after pressure has been relieved. DO NOT USE THE RECOVERY MODE TO RELIEVE LINE PRESSURE. b. Start the evacuation. For a proper evacuation, the cart must pull down to 28-29 in. Hg. at sea level (reduce by 1 in. for each 1000 ft above sea level). Check the low side gauge for proper vacuum level, to make sure the new fittings are operating properly. While the evacuation is being done, the Retrofit label can be filled out and installed (see Step 6). Important: If the compressor was replaced at the same time as this retrofit, and the new compressor was shipped with the correct amount of PAG oil already in it, DO NOT add any additional oil to the system! Go to Step D. If an "oil-less" compressor was installed, add oil in Step C. A new retrofit oil for use with V5 compressor vehicles has been released. This oil will be used ONLY for retrofitted vehicles in which the original V5 compressor is retained. IT WILL NOT BE USED IF A COMPRESSOR IS REPLACED AT THE TIME OF THE RETROFIT. Failure to use this oil may significantly shorten the useful life of the compressor. Important: If the V5 Retrofit oil is not available from GMSPO, the compressor MUST BE REPLACED! To summarize the correct retrofit oil usage: ^ Compressor replaced during retrofit - NO OIL ADDED if new compressor shipped with oil - 8 oz. of PAG oil (9 oz of PAG oil with V5 compressor) added if compressor shipped without oil ("oil-less" design) Left Side Knock Sensor Engine Wiring, LH Side Page 8619 Rear Door Power Window Page 7325 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 5062 Symbol Identification Page 6283 Owners of some 1986-92 S/T Trucks equipped with air conditioning may comment on loose or binding temperature control or HVAC mode selection levers. These conditions may be caused by broken housing bosses at the plate mounting screws on the A/C control (Figure 3). The result may be inability to actuate certain HVAC modes or obtain maximum heating or cooling. Previously it was necessary to replace the complete A/C control assembly to correct this condition. The control assembly included the valves, switches, bezel and lighting. The housing, P/N 16074394, is now available allowing this condition to be corrected when other parts of the control are operating properly. Partial disassembly of the A/C control is required. SERVICE PROCEDURE: 1. Remove the A/C control assembly from the instrument panel. Page 5742 Remove or Disconnect (Figures 1, 2, 3, 5, 6, and 7): Tool Required: J23028-O1 Coil Spring Remover and Installer Raise the vehicle on a hoist so that the control arms hang free. 1. Remove the shock absorber bolts (38) from the shock absorber pivot (39) (Figure 2). a. Push the shock absorber up through the lower control arm (40) and into the spring (37) (Figure 2). b. Cradle the inner control arm bushings using J 23028-01 (Coil Spring Remover and Installer) secured to the end of a suitable jack (Figure 5). 2. Disconnect the stabilizer shaft (53) from the lower control arm (Figure 3). a. Raise the jack to remove the tension on the lower control arm pivot bolts (72 and 77) (Figure 1). b. Secure the lower control arm (40) with a chain around the spring (37) and through the control arm (Figure 1). 3. Remove the lower control arm pivots bolts (72 and 77) and nuts (71 and 78) from the lower control arm (40) (Figure 1). IMPORTANT: Do not force the lower control arm (40) and ball joint (69) in order to remove the coil spring (Figure 1). 4. Remove the coil spring (37) and the insulator (73) from the coil spring (Figure 1). - Position the coil spring (37) properly for easy removal. Page 6115 Blower Motor Resistor: Service and Repair Without A/C Wiring Harness Installation Blower Motor Case Assembly REMOVE OR DISCONNECT 1. Electrical connection (78) from resistor (80). 2. Screws (79). 3. Resistor (80) from blower case (49). INSTALL OR CONNECT 1. Resistor (80) to blower case (49). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 2. Screws (79). - Tighten screws (79) to 2 Nm (18 in. lb.). Diagram Information and Instructions Side Marker Lamp: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Recall 99V193000: ABS 4WD Switch Defective 4WD Switch: Recalls Recall 99V193000: ABS 4WD Switch Defective Description: Certain 4-wheel drive pickup trucks and sport utility vehicles equipped with ABS (antilock braking system) manufactured from September 1989 through August 1996. Under certain driving conditions the switch which signals the ABS system whether the vehicle is in 2-wheel or 4-wheel drive can malfunction causing increased stopping distances during ABS stops while in the two-wheel drive mode. If this occurred at a time when minimum stopping distance was required, a vehicle crash could occur without prior warning. Dealers will replace or repair the 4-wheel/2-wheel drive switch. The first phase of owner notification letters began May 31, 2000, with the last mailing completed by October 2000. Owners can contact Chevrolet at 1-800-222-1020 or GMC at 1-800-462-8782. Also contact the National Highway Traffic Safety Administration's Auto Safety Hotline at 1-888-DASH-2-DOT (1-888-327-4236). Page 4581 Antilock Brake Module: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Locations A/C And Heater Wiring Page 3906 Fluid - A/T: Technical Service Bulletins A/T - Water Or Coolant Contamination Information INFORMATION Bulletin No.: 08-07-30-035B Date: November 01, 2010 Subject: Information on Water or Ethylene Glycol in Transmission Fluid Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks with Automatic Transmission Supercede: This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 08-07-30-035A (Section 07 - Transmission/Transaxle). Water or ethylene glycol in automatic transmission fluid (ATF) is harmful to internal transmission components and will have a negative effect on reliability and durability of these parts. Water or ethylene glycol in ATF will also change the friction of the clutches, frequently resulting in shudder during engagement or gear changes, especially during torque converter clutch engagement. Indications of water in the ATF may include: - ATF blowing out of the transmission vent tube. - ATF may appear cloudy or, in cases of extreme contamination, have the appearance of a strawberry milkshake. - Visible water in the oil pan. - A milky white substance inside the pan area. - Spacer plate gaskets that appear to be glued to the valve body face or case. - Spacer plate gaskets that appear to be swollen or wrinkled in areas where they are not compressed. - Rust on internal transmission iron/steel components. If water in the ATF has been found and the source of the water entry has not been identified, or if a leaking in-radiator transmission oil cooler is suspected (with no evidence of cross-contamination in the coolant recovery reservoir), a simple and quick test kit is available that detects the presence of ethylene glycol in ATF. The "Gly-Tek" test kit, available from the Nelco Company, should be obtained and the ATF tested to make an accurate decision on the need for radiator replacement. This can help to prevent customer comebacks if the in-radiator transmission oil cooler is leaking and reduce repair expenses by avoiding radiator replacement if the cooler is not leaking. These test kits can be obtained from: Nelco Company Test kits can be ordered by phone or through the website listed above. Orders are shipped standard delivery time but can be shipped on a next day delivery basis for an extra charge. One test kit will complete 10 individual fluid sample tests. For vehicles repaired under warranty, the cost of the complete test kit plus shipping charges should be divided by 10 and submitted on the warranty claim as a net item. The transmission should be repaired or replaced based on the normal cost comparison procedure. Important If water or coolant is found in the transmission, the following components MUST be replaced. - Replace all of the rubber-type seals. - Replace all of the composition-faced clutch plates and/or bands. - Replace all of the nylon parts. - Replace the torque converter. - Thoroughly clean and rebuild the transmission, using new gaskets and oil filter. Important The following steps must be completed when repairing or replacing. Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052F- Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow. - Thoroughly inspect the engine cooling system and hoses and clean/repair as necessary. Page 1999 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 2281 Coolant Temperature Sensor/Switch (For Computer): Description and Operation ECT Circuit (Typical) Engine Coolant Temperature Sensor PURPOSE Engine Coolant Temperature (ECT) Sensor is used to control: Exhaust Gas Recirculation (EGR) - Fuel delivery - Idle Air Control (IAC) - Ignition Control (IC) - Torque Converter Clutch (TCC) OPERATION The ECT sensor is a thermistor that is located in the engine coolant flow. Low coolant temperature sensor produces a high resistance (100,000 ohms at -40°C/-40°F). High coolant temperature, produces a low resistance (70 ohms at 130°C/266°F). The control module sends a 5.0 volt signal to the ECT through a resistor in the control module and measures the voltage. The voltage will be high when the engine is cold and low when the engine is hot. Engine coolant temperature affects most systems controlled by the control module. The control module uses information from the ECT to calculate spark advance as follows: Cold engine results in more spark advance. - Hot engine results in less spark advance. Page 3116 Electrical Connectors - Side View Page 3942 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 5252 Symbol Identification Page 3738 PROM - Programmable Read Only Memory: Application and ID Footnotes 151 Thru 200 [151] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [152] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [153] Driveability improvement and eliminate FALSE "Service Engine Soon" lights. FOR 2WD USE 16120099 (SCAN I.D. = 9941). FOR 4WD USE 16120109 (SCAN I.D. = 9901). [154] Driveability improvement and eliminate FALSE "Service Engine Soon" lights. FOR 2.73 (GU2) AXLE USE 16120077 (SCAN I.D. = 9891). FOR 3.08 (GU4) AXLE USE 16120082 (SCAN I.D. = 9901). FOR 3.42 (GU6) AND 3.73 (GT4) AXLES USE 16120086 (SCAN I.D. = 9911). [155] Driveability improvement and eliminate FALSE "Service Engine Soon" lights. FOR 2WD USE 16120042 (SCAN I.D. = 9991). FOR 4WD USE 16120129 (SCAN I.D. = 0011). [156] Prom calibration. FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228486 AAND 1050. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062797 AAND 2798. [157] FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228487 AANF 1052. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062801 AANF 2802. [158] Spark knock only. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [159] Spark knock only. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [160] Detonation. USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [161] USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [162] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [163] USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [164] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [165] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [166] Hard start when hot and detonation. USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [167] Hard start when hot and detonation. USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [168] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [169] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [170] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. Page 5595 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 5183 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 4930 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Locations Air Intake Ducts 4.3W S/T Utility Heater Core Replacement Heater Core: Service and Repair Heater Core Replacement Remove or Disconnect Page 3085 PURPOSE The catalytic converter is an emission control device added to the exhaust system to effectively reduce the levels of carbon monoxide, hydrocarbons, and in some cases oxides of nitrogen, entering the atmosphere. The converter serves two purposes: it permits a faster chemical reaction to take place and although it enters into the chemical reaction, it remains unchanged, ready to repeat the process. CONSTRUCTION AND OPERATION General Motors uses four different converter designs in conjunction with two types of catalysts. The four converter designs, are: single bed monolith, dual bed monolith, single bed pellet and dual bed pellet. The two types of catalysts used are an oxidation catalyst and a three-way (reduction) catalyst. The oxidation catalyst is coated with material containing platinum and palladium which lowers levels of carbon monoxide and hydrocarbons. The three-way (reduction) catalyst is coated with platinum and rhodium which lowers levels of oxides of nitrogen (NOx), as well as carbon monoxide and hydrocarbons. All dual bed converters, whether monolith or pellet type, contain both oxidation and three-way catalysts. Due to its high operating temperatures, the catalytic converter usually requires the use of heat shields. Heat shields are necessary to protect chassis components, passenger compartment and other areas from heat related damage. A fill pipe restrictor is used on catalytic converter equipped vehicles, to prevent the larger service station pump nozzle, used for leaded fuels, being inserted into the filler tube. Since the use of leaded fuels contaminates the catalysts, rendering them ineffective, the use of unleaded fuels is mandatory in catalytic converter equipped vehicles. Door Side Glass, Front - Binding/Track Disengagement Window Frame: Customer Interest Door Side Glass, Front - Binding/Track Disengagement Number: 93-89-10 Section: 10 Date: JAN. 1993 Corporate Bulletin No.: 261614 ASE No.: B1 Subject: FRONT DOOR SIDE GLASS BINDING/TRACK DISENGAGEMENT Model and Year: 1982-93 S/T TRUCKS Owners of some 1982-1993 S/T vehicles may comment about the side front door glass binding during operation or the glass disengaging from the window track. These conditions may occur if the glass binds against the run assembly weatherstrip, and/or the plastic window guide separates from the glass due to improper seating during installation and/or breaks. To correct, it is necessary to replace the following items: - The side door glass with glass that has the lower rear corner rounded off. The new glass reduces binding between the glass and run assembly weatherstrip during window operation. - The run assembly weatherstrip with a weatherstrip that has additional flocking (Figure 1, Section A-A). The additional flocking helps eliminate friction between the glass and channel providing smoother window operation. Page 6694 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 975 2. Remove the serpentine belt from the accessory drive system. 3. Install the tool onto the power steering pulley. Position the legs of the tool into the outer grooves of the pulley, farthest from the front of the engine. 4. Install the retaining cord around the pulley and to the legs of the tool. 5. Put on the laser safety glasses provided with the tool. 6. Depress the switch on the rear of the tool to activate the light beam. 7. Rotate the power steering pulley as required to project the light beam onto the crankshaft balancer pulley grooves. 8. Inspect for proper power steering pulley alignment. - If the laser beam projects onto the second rib or raised area (1), the pulleys are aligned properly. - If the laser beam projects more than one-quarter rib 0.9 mm (0.035 in) mis-alignment, adjust the position of the power steering pulley as required. - Refer to SI for Power Steering Pulley Removal and Installation procedures. 9. Install the serpentine belt to the accessory drive system in the original orientation. 10. Operate the vehicle and verify that the belt noise concern is no longer present. Tool Information Please visit the GM service tool website for pricing information or to place your order for this tool. Capacity Specifications Engine Oil: Capacity Specifications Engine Oil without Filter ....................................................................................................................... ............................................... 4.0 quarts (3.8 liters) NOTE: All capacities are approximate. When adding, be sure to fill to the approximate level. Recheck fluid level after filling Glass/Body - Windshield Wiper Performance Windshield: All Technical Service Bulletins Glass/Body - Windshield Wiper Performance INFORMATION Bulletin No.: 06-08-43-003C Date: February 21, 2011 Subject: Windshield Wiper Performance, Cleaning Instructions and Maintenance Models: 2012 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2010 and Prior Isuzu Medium Duty Trucks 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2011 and 2012 model year. Please discard Corporate Bulletin Number 06-08-43-003B (Section 08 - Body and Accessories). Wiper Concerns Most concerns about windshield wiper performance are the result of dirty wiper blades, damaged wiper blades, or worn out blades that are continuing to be used beyond their useful life. Depending on environmental conditions, wiper blades can have dramatic differences in lifespan. Here are some tips and guidelines to maximize wiper performance to avoid damage to the blades, and to avoid unnecessary replacements. Many wiper blades are being replaced under warranty with reviews showing there is nothing wrong with the returned blades other than a build-up of dirt. Additionally, advise the customer to review the information in their Owner Manual. Inspection and Cleaning Scheduled Maintenance - Inspect your wipers rubber blades every 4-6 months or 12,000 km (7,500 mi) for wear, cracking or contamination. - Clean the windshield and the rubber wiper blades (using the procedure below) if the blades are not clearing the glass satisfactorily. If this does not correct the problem, then replace the rubber elements. Cleaning Procedure Important Avoid getting windshield washer fluid on your hands. Wear rubber gloves or avoid direct contact with washer fluid. Important Do not use gasoline, kerosene, or petroleum based products to clean wiper blades. - Clean the rubber blades using a lint free cloth or paper towel soaked with windshield washer fluid or a mild detergent. You should see significant amounts of dirt being removed on the cloth. - Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road grime, sap and a buildup of car wash/wax treatments may additionally cause wiper streaking. Tip For a larger scale buildup on the windshield, use a non-abrasive cleaner such as Bon-Ami* (www.faultless.com) cleanser with a wet sponge, being sure to use plenty of water to avoid scratching the glass. Flush the surface and body panels completely. Tip For day-to-day exterior glass cleaning and to maintain a streak free appearance, suggest Vehicle Care Glass Cleaner, P/N 88862560 (in Canada, 992727). This product is an easy to use foaming cleaner that quickly removes dirt and grime from glass surfaces. Tip Interior glass should be cleaned with plain, clean water to eliminate any film or haze on the window and help prevent fogging, a major customer dissatisfier. Refer to Corporate Bulletin Number 03-00-89-006D for more information. The New Vehicle Pre-Delivery Inspection form also recommends using plain water to clean interior glass. *"We believe this material to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or any such items which may be available from other sources. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: Customer Interest Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 6136 Installing The Drive Plate - Install J 9401-A on the threaded end of the shaft. - Back off J 9401-A body to allow the center screw to be threaded against the end of the compressor shaft (39). - Hold the center screw with a wrench and tighten the hex portion of J 9401-A body while pressing the hub onto the shaft (39). After tightening the body several turns, remove J 9401-A and check that the shaft key (36) is properly in place in the keyway. - Air gap between contact surfaces of the clutch plate and hub assembly (2) and the pulley (6) should be 0.56-1.34 mm (0.022-0.057 inch). - Remove J 9401-A. Inspect - Position of the shaft (39) (even with or slightly above the clutch hub). 3. Shaft nut (1). - Use J 25030-A to hold the clutch plate and hub assembly (2). Tighten Shaft nut (1) to 27 N.m (20 ft.lbs.) with J 9399-A. - Hand spin the pulley (6) to check for free rotation. Clutch Rotor and Bearing Assembly Service and Repair Crankshaft Main Bearing Seal: Service and Repair Fig. 17 Installing Rear Main Oil Seal 1. Remove transmission. 2. Remove clutch and flywheel, if equipped. 3. Remove rear crankshaft oil seal by placing screwdriver in notches provided and pry the seal out. 4. After cleaning groove, apply a thin even coat of adhesive, part No. 1052621, Loctite 414 over entire surface of seal groove. 5. Within one minute install seal using seal installer J-35621 or equivalent, Fig. 17. 6. Reverse steps 1 and 2 to complete installation. Page 5251 Symbol Identification Page 353 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 4393 Fig. 6 Installing Bearing Cups Into Driveshaft Yoke Assembly 1. If old parts are to be reassembled, pack bearing cups with universal joint grease. Do not fill cups completely or use excessive amounts as over-lubrication may damage seals during reassembly. Use new seals if available. 2. If new parts are being installed, check new bearings for adequate grease before assembling. 3. With the pusher (smaller) socket, press one bearing cup part way into driveshaft. Position spider into the partially installed cup. Place second bearing cup into driveshaft. Fasten driveshaft in vise so that cups are in contact with faces of vise jaws, Fig. 6. Some spiders are provided with locating lugs which must face toward driveshaft when installed. 4. Press bearing cups all the way into position and install snap rings or retainer plates. 5. Install bearing cups in yoke in same manner. When installation is completed, check U-joint for binding or roughness. If free movement is impeded, correct the condition before installation in vehicle. Without Joint Replacement Fig. 1 Production Type Universal Joints Which Use Nylon Injection Rings In Place Of Snap Rings Fig. 2 Service Type Universal Joints (Internal Snap Ring Type) Page 3740 DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [189] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [190] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [191] Information on PROM calibrations. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [192] Information on PROM calibrations. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [193] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [194] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [195] FOR USE WITH MODEL C1 TRUCKS - USE 16121162 (SCAN I.D. = 3511). FOR USE WITH MODEL C2, K, K2, AND K1000 TRUCKS USE 16121166 (SCAN I.D. = 3521). [196] Engine surge. ALSO REQUIRES INSTALLATION OF NEW EGR VALVE PACKAGE P/N 17112238 (CONTAINS EGR VALVE P/N 17090078 AND A GASKET). [197] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [198] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [199] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [200] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. Page 4108 When the converter clutch valve train has been eliminated, there will be a sleeve and plug installed as illustrated. Page 2269 Fan Clutch: Component Tests and General Diagnostics Bi-Metallic Coiled Spring Removal Do not operate the engine until the fan has been first checked for possible cracks and separations. Run the engine at a fast idle speed (1000 RPM) until normal operating temperature is reached. Regardless of temperatures, the unit must be operated for at least five minutes immediately before being tested. Stop the engine, then using a glove or a cloth to protect the hand, immediately check the effort required to turn the fan. If considerable effort is required, it can be assumed that the coupling is operating satisfactorily. If very little effort is required to turn the fan, it is an indication that the coupling is not operating properly and should be replaced. The clutch fan may be tested while the vehicle is being driven. To check, disconnect the bimetal spring, Fig. 3, and rotate 90° counterclockwise. This disables the temperature-controlled, free-wheeling feature and the clutch performs like a conventional fan. If this cures the overheating condition, replace the clutch fan. Page 8126 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 7243 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 6966 Important: If the original pre-load torque value was < (less than) 3 lb.in., then reset torque specifications to 3-5 lb.in. Important: If the pinion seal and collapsible spacer are replaced, then refer to the appropriate Unit Repair Manual of pinion re-load specifications. 4. Install the "Dual Double Cardon" two piece propeller shaft and attaching bolts and nuts. 5. Apply a coating of GM P/N 12345382 Thread Lock or Loctite(R) # 242 or equivalent to the mounting bolt threads to flange. Tighten Tighten bolts to 50 Nm (37 lb.ft.). 6. Install the rear axle brake drum and wheel assemblies. 7. Add lubricant to the rear axle as necessary. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty. Page 3143 Positive Crankcase Ventilation Valve: Locations STD Engine Engine Compartment Components. RH Front Top Of Engine Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 Engine Page 4931 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 4317 Pinion Gear: Adjustments Corporate and Eaton 7 1/2 - 8 7/8 Inch Ring Gear Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly J-23597-01 for models with 7-1/2 inch ring gear, J-21777-01 Page 55 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Locations Brake Fluid Level Sensor/Switch: Locations At Brake Fluid Reservoir Specifications Manifold Pressure/Vacuum Sensor: Specifications Voltage 3.6 to 5.2 V at 1000 to 2000 ft 3.5 to 5.1 V at 2000 to 3000 ft 3.3 to 5.0 V at 3000 to 4000 ft 3.2 to 4.8 V at 4000 to 5000 ft 3.0 to 4.6 V at 5000 to 6000 ft 2.9 to 4.5 V at 6000 to 7000 ft 2.8 to 4.3 V at 7000 to 8000 ft 2.6 to 4.2 V at 8000 to 9000 ft 2.5 to 4.0 V at 9000 to 10000 ft Page 847 Wiper Switch: Service and Repair Fig. 8 Windshield Wiper Switch Removal (Front). Except Tilt Column Fig. 9 Windshield Wiper Switch Removal (Front). Tilt Column FRONT 1. Remove turn signal switch. Refer to Vehicle Lighting/Turn Signals/Turn Signal Switch/Service and Repair procedure. 2. Refer to Figs. 8 and 9 for wiper switch replacement. Page 4676 Do not re-install the spindle nut and attempt to slide-hammer the grease seal from the hub. WHEEL BEARING REPACKING - The hub and spindle should be thoroughly cleaned of all old grease. - The bearings should be cleaned in solvent and allowed to dry completely. WARNING: Do not spin dry the bearings with compressed air, this practice can rapidly damage bearings. - If possible use a commercial wheel bearing packer, otherwise repack the bearings by hand. Hand Repacking Place a quantity of high-temperature, multi purpose wheel bearing grease in the palm of your hand. - Cup the bottom of the bearing cage (the wider end) into the palm of your hand forcing grease up through the cage. Repeat the procedure until the new grease is pushed out of the top of the cage. - Repeat this around the entire circumference of the bearing. - Apply a coating of new wheel bearing grease to the spindle and the inside of the hub. NOTE: The hub should not be completely packed with new grease. As the brakes are applied the hub will heat up and the grease will expand. If an excessive amount of grease is prepacked into the hub, upon heating it will force its way past the grease seals and contaminate the brake system. - Also apply a thin coating of grease to the inside lip of the new grease seals. NOTE: The side of the grease seal from which the spring is visible should point towards the bearing. Page 1727 Valve Clearance: Specifications Valve Arrangement All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E Page 8668 Front Door Trim Panel Page 7185 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 4185 For vehicles repaired under warranty use: Page 5165 Symbol Identification Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Diagram Information and Instructions Fuse Block: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Brake Light Switch Brake Light Switch: Locations Brake Light Switch Cruise Control I/P Wiring Page 3327 Fuel Return Line: Service and Repair Fuel Tank/Lines Cleaning WARNING: This procedure will NOT remove all fuel vapors. DO NOT attempt any repair on the fuel tank or filler neck where heat or flame is required, as an explosion resulting in personal injury could occur. NOTE: If the fuel is contaminated, or if there is foreign material in the tank, the tank can usually be cleaned. If the tank is rusted internally, it should be replaced. PROCEDURE: 1. Disconnect the negative battery cable. 2. Disconnect the engine harness at the DIS coil module. 3. Place a dry chemical (Class B) fire extinguisher near the work area. 4. Relieve the fuel system pressure, refer to FUEL SYSTEM PRESSURE RELIEF. 5. Drain the fuel tank, refer to FUEL TANK DRAINING. 6. Remove the fuel tank, refer to FUEL TANK REMOVAL AND FUEL LEVEL SENDING UNIT. 7. Remove the external fuel filter and inspect for contamination. If the filter is plugged, replace it. 8. Move the tank away from heat, flame or other source of ignition. Remove the fuel level sending unit and inspect the condition of the strainer. If the strainer is contaminated, install a new strainer when reassembled. 9. Complete draining the tank by rocking it and allowing the fuel to run out of the fuel pump/level sending unit tank opening. 10. Purge the fuel tank, refer to FUEL TANK PURGING. 11. Disconnect the fuel feed pipe at the in-line filter and use air pressure to clean the fuel line. Apply air pressure in the opposite direction the fuel normally flows through the line. Disconnect the return line and apply air pressure to clean. 12. Use low air pressure to clean pipes on the fuel level sender unit assembly. 13. Install a new filter strainer on the fuel level sending unit, if required. 14. Install the fuel level sending unit with a new O-ring gasket into the tank and install the fuel tank. Connect the fuel level sender harness to the body harness. The fuel level lender harness must be routed below the sender unit fuel pipes. Connect all fuel lines except the feed line at the engine. Install the fuel filter. NOTE: Care should be taken not to fold over or twist the strainer when installing the fuel level sending unit as this will restrict the flow. Also, assure that the strainer does not block the float arm full travel. 15. Connect a hose to the fuel feed line at the engine, and insert the other end of the hose into an empty one gallon fuel can. 16. Connect the battery cable. 17. Put 2.3 liters (six gallons) of clean fuel into the fuel tank and apply 12 volts to terminal "G" of the ALDL to operate the fuel pump. Pump two quarts of fuel into the can. This will purge the fuel pump and the fuel lines. 18. Remove the hose and reconnect the fuel line to the engine. Connect the engine harness connector to the DIS ignition module. 19. START the engine. 20. Check all connections for leaks. Tighten all hose clamps. Locations Power Window And Door Lock Body Wiring W/Outside Power Mirrors Page 1127 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Page 5745 Suspension Spring ( Coil / Leaf ): Specifications Leaf Spring U-Bolt Nuts 85 ft.lb Shackle To Frame Bolt 92 ft.lb Shackle To Front Bracket Bolt 92 ft.lb Shackle To Spring Bolt 92 ft.lb Page 5605 Power Steering Pump: Description and Operation Less Integral Reservoir The hydraulic pump is a non-submerged vane-type design. The housing and internal parts are separate from the reservoir and are not submerged in fluid. There are two bore openings at the rear of the pump housing. The larger opening contains the cam ring, pressure plate, thrust plate, rotor and vane assembly, and end plate. The smaller opening contains the pressure line union, flow control valve and spring. the pressure relief valve inside the flow control valve limits pump pressure. Page 4600 Fig. 8 Crimping the Splice Clip Fig. 9 Completing the Crimp Select the proper clip to secure the splice. To determine the proper clip size for the wire being spliced, follow the directions included in the J 38125-A Terminal Repair Kit. Select the correct anvil on the crimper. On most crimpers your choice is limited to either a small or large anvil. Overlap the stripped wire ends and hold them between your thumb and forefinger as shown in Fig. 7. Then, center the splice clip under the stripped wires and hold it in place. ^ Open the crimping tool to its full width and rest one handle on a firm flat surface. ^ Center the back of the splice clip on the proper anvil and close the crimping tool to the point where the former touches the wings of the clip. ^ Make sure that the clip and wires are still in the correct position. Then, apply steady pressure until the crimping tool closes, Fig. 8. ^ Before crimping the ends of the clip, be sure that: ^ The wires extend beyond the clip in each direction. ^ No strands of wire are cut loose, and ^ No insulation is caught under the clip. Crimp the splice again, once on each end. Do not let the crimping tool extend beyond the edge of the clip or you may damage or nick the wires, Fig. 9. Step 5: Solder Apply 60/40 rosin core solder to the opening in the back of the clip, Fig. 10. Follow the manufacturer's instruction for the solder equipment you Page 427 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 5484 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Locations RH Door Harness (LH Typical) Page 5038 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 8776 Wiper Switch: Service and Repair Fig. 8 Windshield Wiper Switch Removal (Front). Except Tilt Column Fig. 9 Windshield Wiper Switch Removal (Front). Tilt Column FRONT 1. Remove turn signal switch. Refer to Vehicle Lighting/Turn Signals/Turn Signal Switch/Service and Repair procedure. 2. Refer to Figs. 8 and 9 for wiper switch replacement. Page 187 ECM QDR Check Procedure Page 970 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Page 3934 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 6765 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Locations Malfunction Indicator Lamp: Locations Instrument cluster. Description and Operation Overvoltage Protection Relay: Description and Operation PURPOSE Inform the control module that there is a basic generator over voltage problem. OPERATION PCM/ECM If voltage is greater than 19.5 volts for 2 seconds at PCM terminal "E16" (ECM is "C16"), the control module sets Diagnostic Trouble Code 53, the automatic transmission pressure control solenoid is turned "OFF", the automatic transmission shifts immediately to third gear, and TCC operation is inhibited. (the setting of additional DTC's may result.) VCM If voltage is greater than 17.1 volts at VCM terminal "GR2" sets Diagnostic Fault Code P1632. For 2 seconds after the fault is detected, the VCM will disengage its outputs. This may result in additional DTC's being set. Page 97 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 6922 Trailer Wiring Page 4075 Torque Converter Clutch: Symptom Related Diagnostic Procedures Converter Shudder 1. Converter clutch pressure plate damaged. 2. Check ball on end of turbine shaft damaged. 3. Sticking converter clutch shift valve in valve body. 4. Sticking converter clutch apply valve in valve body. 5. Restricted converter clutch apply passage. 6. Low oil or oil pressure. 7. Engine not tuned properly. No Torque Converter Clutch Apply 1. 12 volts not being supplied to the transmission. 2. Defective transmission outside electrical connector. 3. Defective inside electrical connectors, wiring harness, solenoid. 4. Defective electrical ground inside transmission. 5. Defective pressure switch or improper connection. 6. Solenoid not grounded. 7. Valve body converter clutch shift or throttle valve sticking. 8. Valve body casting or spacer plate in converter clutch valve area are improperly positioned or damaged. 9. Converter clutch apply valve, stuck or installed backwards. 10. Pump assembly signal oil orifice, restricted or missing. 11. Pump assembly O-ring on solenoid damaged or missing. 12. Pump to case gasket, damaged or improperly positioned. 13. Pump assembly cup plug missing from apply passage. 14. Pump assembly orifice plug missing from the cooler input passage. 15. High or uneven bolt torque on cover to body. 16. Converter clutch stop valve or retainer ring not installed properly. No Torque Converter Clutch Release 1. Converter clutch apply valve stuck in the open position. 2. O-ring or check ball in the end of the turbine shaft damaged. 3. Internal converter damage. Page 2816 CMFI Intake Manifold Sensors/Valves Page 5322 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 7292 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 8380 Side Marker Lamp: Component Tests and General Diagnostics Front Park And Side Marker Lamps Do Not Operate Rear Lamp Systems Do Not Operate Page 3097 Evaporative Emission Control Canister: Service and Repair Removal - Remove hoses from canister. Mark hoses for installation of new canister. - Remove screw from bracket and canister. Installation - Install new canister and secure to bracket with screw. - Connect hoses to canister making sure hoses are connected to the correct ports. - Check operation of new canister. Page 5979 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Page 3310 Fuel Pressure Test Port: Service and Repair Fuel Pressure Connection CLEAN Area around fuel pressure connection with GM X-30A or equivalent. REMOVE OR DISCONNECT - Negative battery terminal. - Relieve fuel system pressure. - Fuel pressure connection and seal. Discard seal. INSTALL OR CONNECT - New seal on fuel pressure connection. - Fuel pressure connection in fuel rail. Tighten Fuel pressure connection assembly to 10.0 N-m (88 lb. in.). - Tighten fuel filler cap. - Negative battery terminal. INSPECT - Turn ignition switch to the "ON" position for two seconds, then turn to the "OFF" position for ten seconds. Again turn to the "ON" position, and check for fuel leaks. NOTE Any time the battery is disconnected, the programmed position of the IAC valve pintle is lost, and replaced with a default value. To return the IAC valve pintle to the correct position, perform the following procedure: - Disconnect negative battery for at least ten seconds to clear control module memory. (Ensure ignition is "OFF".) - Reconnect negative battery cable. - "START" engine and allow engine to reach operating temperature. Check for proper idle operation. Page 2166 Coolant: Technical Service Bulletins Warranty - Recycled Engine Coolant Policy Group Ref.: Warranty Administration Bulletin No.: 310504 Date: February, 1994 WARRANTY ADMINISTRATION SUBJECT: RECYCLED ENGINE COOLANT POLICY MODELS: 1994 AND PRIOR PASSENGER CARS AND TRUCKS ATTENTION: WARRANTY CLAIMS ADMINISTRATOR AND SERVICE MANAGER General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. For detailed information on GM approved engine coolant recycling equipment guidelines refer to the following bulletins: Cadillac 93-1-18, GMC Truck 93-6B-34, Chevrolet 93-73-6B, Pontiac 93-6-18, Oldsmobile 1-93-43, Buick 93-6B-1 (Corporate Number 236203). Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial to assure that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words, if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Engine - Valvetrain/Lifter Noise Lifter / Lash Adjuster: All Technical Service Bulletins Engine - Valvetrain/Lifter Noise Group Ref.: Engine Bulletin No.: 376006 Date: December, 1993 SUBJECT: VALVETRAIN/LIFTER NOISE (ADJUST LASH/INSTALL ADJUSTABLE LASH) MODELS: 1992-93 C/K AND S/T TRUCKS; M/L AND G VANS WITH LB4 4.3L V6 TBI (VIN Z) OR L35 4.3L V6 CPI (VIN W) ENGINE THIS BULLETIN CANCELS AND SUPERSEDES CORPORATE BULLETIN 376107. PLEASE DISCARD PREVIOUS DIVISIONAL PUBLICATIONS: (see illustration) CONDITION: Some owners may report a tick, click, or clatter noise occurring on start up, with the engine hot and/or cold. This valvetrain/lifter noise may last up to one minute. CORRECTION: Page 2438 ECM QDR Check Procedure Page 1922 Intake Manifold: Technical Service Bulletins Engine - Revised Upper Intake Manifold Torque Specs Number: 92-313-6E Section: 6E Date: OCT. 1992 Corporate Bulletin No.: 266501 ASE No: A1, A8 Subject: UPPER INTAKE MANIFOLD FASTENER TORQUE SPECIFICATIONS Model and Year: 1992 S/T AND M/L TRUCKS WITH 4.3L ENGINE SERVICE UPDATE The following represents new and/or revised information for Section 4 at the rear of ST 369-92 (S/T) or ST 372-92 (ASTRO VAN) Service Manuals. This information replaces the torque specification (upper intake manifold bolts and studs) found under UPPER INTAKE INSTALLATION on pages 4-79 and 4-80 in ST 369-92 (S/T) and ST 372-92 (ASTRO VAN) Service Manuals. The torque specification for the 4.3L (VIN W - RPO L35) engine upper intake manifold bolts and studs is 10 N-m (88 lbs.in.). Page 4877 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Specifications Exhaust Manifold: Specifications Exhaust Manifold Bolts Center Two Bolts 36 ft.lb All others 28 ft.lb Page 4361 6. Reverse foregoing procedure to install the axle shaft. Axle Assembly REAR AXLE ASSEMBLY 1. Raise and support vehicle. Using a jack, support rear axle assembly. 2. Drain fluid from axle assembly. 3. Mark driveshaft to flange, then disconnect driveshaft and tie driveshaft to side rail or crossmember. 4. Tape bearing cups to prevent loss of the rollers. 5. Remove wheel and brake drum or hub and drum assembly. 6. Disconnect parking brake cable from lever and brake flange plate. 7. Disconnect and cap hydraulic brake lines from connectors. 8. Remove shock absorbers from axle brackets. 9. Disconnect vent line from vent fitting. 10. Remove height sensing and brake proportional valve brackets. 11. Remove nuts and washers from U-bolts. 12. Carefully remove U-bolts, spring plates and spacers from axle assembly. 13. Lower axle assembly from vehicle. 14. Reverse procedure to install. Axle Housing REAR AXLE HOUSING Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and place jackstands under frame side rails. Support axle housing with a suitable jack. 2. Drain lubricant from axle housing and remove propeller shaft. 3. Remove wheel and brake drum. 4. Disconnect parking brake cable from lever and at brake flange plate. 5. Disconnect hydraulic brake lines from connector and lower shock mounting from axle brackets. 6. Remove vent hose from axle vent fitting if equipped. 7. Disconnect height-sensing and brake proportioning valve linkage if equipped. 8. Support assembly with a hydraulic jack and remove rear stabilizer bar. 9. Remove U-bolts, spring plates and spacers from axle assembly. 10. Lower jack and axle assembly. 11. Reverse procedure to install. Axle Shaft, Oil Seal & Bearing REAR AXLE SHAFT, OIL SEAL AND BEARING Fig. 1 Position Case For Clearance Fig. 2 Axle Shaft & Housing Components. Chevrolet Semi-Floating Axle Page 2050 - Charge NC system. Page 8111 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Testing and Inspection Parking Brake Cable: Testing and Inspection Inspect parking brake cable end for kinks, fraying and elongation, and replace as necessary. Use a small hose clamp to compress clamp where it enters backing plate to remove. Page 7439 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. A/T - No Transmission Downshift/80-85% Throttle Throttle Cable/Linkage: Technical Service Bulletins A/T - No Transmission Downshift/80-85% Throttle Number: 92-84A-7A Section: 7A & 6C Date: MARCH 1992 Corporate Bulletin No.: 167106R ASE No.: A1, A2, A8 Subject: NO TRANSMISSION DOWNSHIFT AND/OR 80-85% THROTTLE Model and Year: 1991-92 S/T TRUCKS WITH 4.3L ENGINE AND AUTOMATIC TRANSMISSION THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-84-7A DATED FEBRUARY, 1992. THE VIN BREAKPOINTS HAVE BEEN REVISED. ALL COPIES OF 92-84-7A SHOULD BE DISCARDED. Owners of some 1991 and 1992 S/T vehicles equipped with an automatc transmission and a 4.3L (LB4) engine may comment that their vehicle exhibits some of the following symptoms: - Poor performance - Lack of power - Sluggishness - No downshift IMPORTANT: THE SYMPTOMS FEEL LIKE TRANSMISSION FAILURE (LACK OF RESPONSE) BUT TRANSMISSION REPLACEMENT IS NOT NECESSARY. These symptoms may be due to the accelerator cable being too long and/or the accelerator pedal having incorrect geometry. When one or both of these conditions are present, full throttle is not achieved. To correct this condition, replacement of accelerator pedal and/or cable with revised units is necessary for the 4.3L (LB4) engine. VEHICLES INVOLVED Involved are certain S/T vehicles with 4.3L (LB4) engines and automatic transmissions built before the following VIN Breakpoints: FOR THE ACCELERATOR CABLE MODEL YEAR PLANT FROM TO 1991-92 Pontiac SOP 91 1GNCS18Z7N0110865 1991-92 Shreveport SOP 91 1GCCS19ZXN8127815 1991-92 Moraine SOP 91 1GCCS19Z7N2122624 FOR THE PEDAL/LEVER ASSEMBLY MODEL YEAR PLANT FROM TO 1991-92 Pontiac SOP 91 1GNCS18Z4NO119040 1991-92 Shreveport SOP 91 1GCCS14Z0N8144551 1991-92 Moraine SOP 91 IGNDT13Z0N2121994 SERVICE PROCEDURE: 1. Before replacing the accelerator cable and/or pedal assembly, connect TECH 1 or similar testing device to get a throttle position sensor (TPS) Page 5243 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Locations Daytime Running Lamps, I/P Wiring Page 4798 Brake Master Cylinder: Fundamentals and Basics Parts Reminder List RECOMMENDED PARTS Basic Service, Replacement New or rebuilt master-cylinder - Fresh/New brake fluid If Overhaul is Required Master cylinder overhaul kit - Brake assembly lubricant Optional Aerosol brake cleaner. New or Rebuilt Master Cylinder Always closely compare the new master-cylinder with the old master-cylinder. Minor variations in the size and depth of the primary piston can result in significant reductions in braking performance. Examine the end of the master-cylinder where the pushrod contacts the piston. The depth and diameters of the pistons should match. Brake Fluid Proper bench bleeding the master-cylinder and flushing the brake system will require a minimum of 16 oz of brake fluid. - Never Mix DOT 3 (light amber in color) with DOT 5 (purple in color). There have been reports of damage to brake system seals when DOT 3 and DOT 5 fluids are mixed - Always store brake fluid in a sealed container. When left open brake fluid will absorb moisture from the air. This reduces the boiling point of the brake fluid and could lead to a soft pedal or brake system failure during prolonged or emergency braking. - Never add automatic transmission fluid, engine oil, or power steering fluid to the master-cylinder. Petroleum based fluids will cause the rubber seals and gaskets in the brake system to swell and leak. Master Cylinder Overhaul Kit Overhaul kits will often come with a variety cup and seal sizes. Closely match the old cups and seals with the new ones. Brake Assembly Lubricant Assembly lubricant can greatly simply the master-cylinder overhaul process and prolong the life of the new seals. - Clean brake fluid can be used to lubricate the master-cylinder bore during assembly but assembly lube is much slicker and prevents any sticking or binding and possible damage to the new cups and seals. Aerosol Brake Cleaner - Commercially produced aerosol brake cleaners are designed to effectively clean brake systems while not leaving an oily residue. - Do not use carburetor cleaner or solvent based products to clean brake system components. These products will leave a residue which could contaminate the brake fluid or cause a reduction in braking performance. Page 755 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: All Technical Service Bulletins Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 2842 Manifold Pressure/Vacuum Sensor: Locations CMFI Intake Manifold Sensors/Valves Page 5244 Relay Box: Electrical Diagrams Convenience Center (without Digital Cluster) Page 7522 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7212 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 6208 Installing Clutch Coil Assembly 3. Center the J 8433-1 puller crossbar in the countersunk center hole of the J 33024 clutch coil installer. Install the J 34992-2 through bolts and washers through the crossbar slots and thread them, into the holding fixture J 34992 to full fixture thickness. 4. Turn the center forcing screw of the J 8433-1 puller crossbar to force the clutch coil onto the front head. Be sure clutch coil and J 33024 installer stay "in-line" during installation. Staking Clutch Coil To Front Head 5. When coil is fully seated on the front head, use a 1/8" diameter drift punch and stake the front head at three (3) places 120° apart. to ensure clutch coil remaining in position. Page 4748 Brake Caliper: Service and Repair Rebuild Caliper Assembly DISASSEMBLY 1. Remove caliper. 2. Disconnect hose from steel line, remove U-shaped retainer and withdraw hose from frame support bracket. 3. After cleaning outside of caliper, remove brake hose and discard copper gasket. 4. Drain brake fluid from caliper. Removing Piston 5. Pad caliper interior with clean shop towels and use compressed air to remove piston. Use just enough air pressure to ease piston out of bore. Do not blow piston out of bore. WARNING: Do not place fingers in front of piston in an attempt to catch or protect it when applying compressed air. This could result in serious injury. Page 8143 LH I/P Harness Wiring Page 7384 Symbol Identification Page 653 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION - Connectors and wires - Housing and insulator for cracks/damage - Sensor tip for silicone contamination (white powdery coating) CAUTION Do NOT perform the following test for more than 2 minutes, as this may cause damage to the catalytic converter. PERFORMANCE TEST Checks working range and response (speed). Warm engine - Install DVOM between sensor and ground (2 volt D.C. range) - "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). - Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. - Drive system lean: Create a vacuum leak from a source that is not an control module input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE After each test the O2 sensor should return to normal operating range within two to three seconds. - O2 Sensor should be replaced for failure to pass any of the tests above. NOTE A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. - Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. HEATING ELEMENT (H20S only) - Turn ignition "OFF". Disconnect electrical connector. - Connect test light between harness terminals "A" and "B". - Turn ignition "ON". Test light should be "ON". If test light is "OFF", connect test light to harness terminal "A" to ground. Light should be "ON" ensuring power circuit is operating correctly. - Turn ignition "OFF". - Using an ohmmeter, measure resistance between terminals A and B. Resistance @ Specified Temperature 3.5 ohms @ 20°C (68°F) 14 ohms @ 350°C (662°F) Page 5613 6. Remove attaching bolt from hose bracket. Allow fluid to drain into a suitable container, Fig. 23. 7. Disconnect return and pressure hoses from power steering pump, then cap hoses. 8. Remove attaching bolts from rear bracket at alternator. 9. Lower vehicle. 10. Remove pump and attaching nuts from rear bracket. 11. Reverse procedure to install. Disassembly Fig. 2 Exploded view of power steering pump Refer to Fig. 2, when servicing pump. Before disassembly of pump, remove filler cap and drain fluid. If broken components or foreign materials are found during disassembly, hydraulic system should be disassembled, inspected, cleaned and flushed before servicing is complete. 1. Clean exterior of pump with solvent and crocus cloth. 2. Remove bolt and fitting from rear of pump reservoir, then the reservoir and seals. 3. Remove end plate retaining ring using a screwdriver and punch. 4. Remove end plate and pressure plate spring, then the O-ring, control valve and control valve spring by inverting housing. 5. Tap lightly on driveshaft with a rubber mallet to remove pressure plate. 6. Pull out pump ring and vanes, then remove shaft retaining ring, pump rotor and thrust plate. 7. Remove driveshaft key from slot in shaft, then with end of shaft pointed downward, press down until shaft is free. 8. Remove seals, dowel pins and O-rings. Inspection 1. Clean all parts with solvent and blow dry. 2. Check vane tips for scoring or wear. Vanes must fit snugly but slide freely in slots of rotor. Examine rotor slots for burrs and excessive wear at thrust faces. 3. Check inner surface of pump ring for scoring or wear and thrust plate and pressure plate for wear on plate surfaces. 4. If heavy wear is evident in any of above components, replace entire rotating group. 5. Inspect seal for leakage, cracking or swelling, if evident replace seal. 6. Check driveshaft for excessive burning or scoring. 7. Control valve must move smoothly in the valve bore. Assembly 1. Lubricate O-rings, pump ring, rotor and vanes with power steering fluid. 2. Install O-rings and dowel pins on pump housing. 3. Using a seal installation tool, insert seal into front of housing. 4. Install driveshaft and thrust plate. Ensure counterbore faces driveshaft end of housing and install rotor. 5. Insert vanes into rotor, ensuring rounded edge faces away from rotor. 6. Install shaft retaining ring, pump ring and pressure plate. 7. Insert control valve spring, then install control valve and O-ring. 8. Install pressure plate spring and end plate, then secure with end plate retaining ring. 9. Connect seal and reservoir, then install bolt and fitting. System Bleeding Locations Oil Pressure Switch (For Fuel Pump): Locations Rear Of Engine Oil Pressure Switch 4.3L Utility Page 162 Relay Box: Electrical Diagrams Convenience Center (without Digital Cluster) Cruise Control - Works Intermittently Cruise Control Switch: All Technical Service Bulletins Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Page 8350 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 6099 Push-On Fan-Removal Procedure REMOVE OR DISCONNECT 1. Blower motor and fan assembly. 2. Using a hot knife, cut a slot in cage motor shaft sleeve in three places. Starting 12.7 mm (1/2 inch) from base of shaft, start cut from fan dome and continue to cut through the plastic material to the end of the shaft so that the fan splits from the shaft. 3. Fan cage from blower motor shaft by pulling straight out. Alternative Removal Methods 1. Using small wheel puller: - Remove tip of fan at end of motor shaft using soldering iron or cutting pliers. - Draw fan from motor shaft using a small puller. Hook legs of puller between fan lower rib and motor mounting plate. Thread center post of puller against the end of the motor shaft exposed in the above step. 2. Using drill press or arbor press: - Remove tip of fan at end of motor shaft using soldering iron or cutting pliers. - Support fan with blocks, angle iron, etc. while allowing the motor to be suspended (see accompanying figure). - Place steady pressure on tip of motor shaft, with a drill press or small arbor press and pin arrangement. Motor should fall freely from the fan after moving motor shaft about 12.7 mm (1/2 inch). NOTICE: Do not use force on motor to remove or install fan. Do not apply force to motor housing to seat fan on motor, or force motor/shaft bearing damage could result. Do not apply pressure to fan rim. Be sure correct replacement part is used. Oil Pressure Gauge - Readings are Incorrect or Erratic Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Readings are Incorrect or Erratic BULLETIN NUMBER: 93-8C-28 SECTION: 8C NUMBER: 2 CORPORATE REFERENCE NUMBER: 268304 DATE: November 1992 SUBJECT: INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW OIL PRESSURE SENSOR) MODELS: 1990-93 ALL LIGHT DUTY MODELS Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative. The internal resistance wire in the oil pressure sensor may not be properly supported, resulting in an intermittent open condition. SERVICE PROCEDURE Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the oil pressure sensor following the procedure. 1. Disconnect the negative battery cable. 2. Remove the wiring harness connector from the oil pressure sensor. 3. Remove the oil pressure sensor. 4. Install the new oil pressure sensor. 5. Connect the wiring harness connector to the oil pressure sensor. 6. Connect the negative battery cable. PARTS INFORMATION Page 4966 Symbol Identification Page 1054 Hose/Line HVAC: Vehicle Damage Warnings Handling of Refrigerant Lines and Fittings Pipe And Hose Connections Torque All metal tubing lines should be free of dents or kinks to prevent loss of system capacity due to line restriction. - The flexible hose lines should never be bent to a radius of less than four (4) times the diameter of the hose. - The flexible hose lines should never be allowed to come within a distance of 63.5 mm (2-1/2 inches) of the exhaust manifold. - Flexible hose lines should be inspected regularly for leaks or brittleness and replaced with new lines if deterioration or leaking is found. - When disconnecting any fitting in the refrigerant System, the system must be discharged of all Refrigerant-12. However, proceed very cautiously, regardless of the gage readings. Open very slowly, keeping your face and hands away so that no injury can occur. If pressure is noticed when a fitting is loosened, allow it to bleed off very slowly. - If any refrigerant line is opened to the atmosphere, it should be immediately capped to prevent the entrance of moisture and dirt, which can cause internal compressor wear or plugged lines, in the condenser and evaporator core and expansion (orifice) tubes or compressor inlet screens. - The use of the proper wrenches when making connections on O-ring fittings, is important. The use of improper wrenches may damage the connection. The opposing fitting should always be backed up with a wrench to prevent distortion of connecting lines or components. When connecting the flexible hose connections, it is important that the swaged fitting and the flare nut. as well as the coupling to which it is attached, be held at the same time using three different wrenches to prevent turning the fitting and damaging the seat. - The O-rings and seats must be in perfect condition. The slightest burr or piece or piece of dirt may cause a leak. When replacing the O-ring, first dip it in clean 525 viscosity refrigeration oil. - Tighten tubing connections to the specified torque, refer to accompanying figure. Maintaining Chemical Stability The life and efficient operation of the air conditioning system depends on the chemical stability of the refrigeration system. When foreign materials, such as dirt, air or moisture, contaminate the refrigeration system, they change the stability of the R-12 and 525 viscosity compressor oil. They will also affect the pressure-temperature relationship and reduce efficiency, and could cause internal corrosion and abnormal wear of moving parts. The following general practices should be followed to insure chemical stability in the system: 1. Whenever it becomes necessary to disconnect a hose connection, wipe away any dirt or oil at and near the connection to eliminate the possibility of dirt entering the system. Both sides of the connection should be capped, plugged or taped as soon as possible to prevent the entrance of dirt and moisture. (It must be remembered that all air contains moisture. Air that enters any part of the refrigeration system will carry moisture with it and the exposed surfaces will collect the moisture quickly.) 2. Keep tools clean and dry. This includes the Manifold Gage Set and all replacement parts. 3. When adding 525 viscosity refrigerant oil, the container/transfer tube through which the oil will flow should be exceptionally clean and dry due to the fact that refrigerant oil should be as moisture-free as possible. 4. When it is necessary to "open" an A/C system, have everything needed ready so that as little time as possible will be required to perform the operation. Do not leave the A/C system open any longer than necessary. Page 1531 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Page 417 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 1629 Rocker Arm Assembly: Specifications Rocker Arm Stud Torque ROCKER ARM STUD TORQUE ^ Rocker Arm Stud to Cylinder Head ................................................................................................................................................ 47 Nm (35 lb. ft.). Page 144 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 3594 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Locations LH I/P Harness Wiring Page 4557 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point. Page 7104 Vehicles in dealer inventories should be kept clean and dry. A vehicle that sits unattended, especially after the sun has dried any water on the body surface, is a target for acid rain damage. MATERIALS DESCRIBED IN THIS BULLETIN* WAX AND GREASE REMOVER - USE BELOW OR EQUIVALENT Dupont # 3919S, PPG # DX440, BASF # 900, SIKKENS # 6041 FINESSE POLISHES - USE BELOW OR EQUIVALENT Dupont # 1500S, 3000S; BASF # 563-808, 560-1502; PPG # DRX10; 3M PERFECT-IT * USE V.O.C. EQUIVALENTS IN STATES WITH V.O.C. RESTRICTIONS RAIL DUST REMOVER - USE BELOW OR EQUIVALENT Industrial Fallout Remover # 5029 Zep Corporation Atlanta, GA. Telephone # 404-352-1680 Stain Away # HBY 0160 Hornby Chemical Milwaukee, WI. Telephone # 414-462-2833 If the rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. PAINT GAGES - USE BELOW OR EQUIVALENT Elcometer Inc. 1893 Rochester Ind. Drive Rochester Hills, MI. 48309 (800) 521-0635 or (313) 650-0500 Zelcro, Ltd./Zormco 8520 Garfield Rd. Cleveland, OH 44125 (216) 441-6102 Delfesko Corp. 410 Cedar St. Ogdensburg, NY 13669 (800) 267-0607 or (613) 925-5987 Pro Motorcar Products Inc. 22025 US-19 North Clearwater, FL 34625 (800) 323-1090 (813) 726-9225 "We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources." Technical Service Bulletin # 231054R Date: 930701 Paint - Identification/Repair of Colorcoat Delamination BULLETIN NUMBER: 92-1O-134A SECTION: 10 Body NUMBER: 4 CORPORATE REFERENCE NUMBER: 231054R Page 6671 Symbol Identification Description and Operation Driver Information Center (DIC): Description and Operation DIGITAL I/P The Digital Electronic Instrument Panel contains vacuum fluorescent displays for the Speedometer, Fuel Gage, Oil Pressure Gage, Temperature Gage and Voltmeter. The Turn Lamps, Safety Belt Lamp, SERVICE ENGINE SOON Lamp, BRAKE Lamp, Headlamp High Beam Indicator and SHIFT Lamp (manual transmission) use standard bulbs and operate the same as the Base and Gage Clusters. Battery voltage to the Cluster is supplied by the ORN (40) wire. This circuit voltage is used for the memory to maintain the total and trip mileages for the odometers. Ignition voltage to the Cluster is supplied by the PNK/WHT (39) wire. This circuit supplies voltage to the vacuum fluorescent displays and the BRAKE and SERVICE ENGINE SOON indicators and the Voltmeter. The other circuits to the Cluster provide the various signals necessary to operate the displays and indicators. When the Ignition Switch is turned to RUN, all of the segments of the vacuum fluorescent displays are displayed for about two seconds. The displays then indicate current levels. The vacuum fluorescent displays can be switched between English and Metric by the E/M switch. When the E/M switch is open, the displays are in English. When the E/M switch is closed, the displays are in Metric. CLUSTER DIMMING When the Ignition Switch is in RUN, the displays are at full brightness. When the Light Switch is in PARK or HEAD, the Cluster senses that the lights are on through the BRN (9) wire. This allows the display brightness to be controlled by the Panel and Interior Lamp Switch through the GRA (9) wire. SPEEDOMETER/ODOMETER/TRIP ODOMETER These displays receive a signal from the Vehicle Speed Sensor Buffer (DRAC) through the LT BLU/BLK (824) wire. The Vehicle Speed Sensor Buffer (DRAC) converts the speed signal from the Vehicle Speed Sensor to 4000 pulses per mile. A different Vehicle Speed Sensor Buffer (DRAC) is used for each axle ratio to convert the signal. The Speedometer indicates vehicle speed in miles per hour or kilometers per hour depending on the E/M Switch position. Speeds below 1.4 mph may be displayed as "0." The odometer/trip odometer display is mounted on a separate board attached to the main display board. The odometer displays the total vehicle mileage up to 999,999 miles in the English mode. If the mileage exceeds this, the display flashes ERROR. In Metric mode, the display will flash ERROR when it exceeds 999,999 kilometers. The English display will show the normal display. The display can be switched from total odometer to trip odometer by pushing the trip switch. When the TRIP Switch is open, the total mileage is displayed. When the TRIP Switch is closed, the trip mileage is displayed. The Trip Odometer can be reset to 0 by pushing the RESET Switch. The display must be in the TRIP mode to be reset. The accumulated mileage of the two displays is gored in a nonvolatile memory chip to prevent losing this data if the battery or cluster is disconnected. If the Cluster is replaced, the Odometer Display can be transferred to the new cluster. FUEL GAGE DISPLAY The Fuel Gage Display shows the fuel level in the tank. This signal is supplied to the Cluster through the PNK (3O) wire. With low fuel level in the tank, the sender resistance is low. With high fuel level in the tank, the sender resistance is high. If the fuel level in the fuel tank drops below approximately 11 liters (3 gallons) in a 75-liter (20-gallon) tank, a box around the Fuel Gage ISO Symbol flashes to indicate low fuel level. OIL PRESSURE GAGE DISPLAY The Oil Pressure Gage Display shows the engine operating oil pressure. This signal is supplied to the Cluster through the TAN (31) wire. With low oil pressure, the sender resistance is low. With high oil pressure, the sender resistance is high. If engine oil pressure drops below 69 kPa (10 psi), a box around the Oil Pressure Gage ISO Symbol flashes to indicate low oil pressure. COOLANT TEMPERATURE GAGE DISPLAY The Coolant Temperature Gage Display shows the engine coolant temperature. This signal is sent to the cluster through the DK GRN (35) wire. With Page 6168 Installing - Removing Pulley Rotor & Bearing Assembly Retainer Ring 2. Remove rotor and bearing assembly retaining ring, using snap ring pliers J 6083. Installing Pulley Rotor/Bearing Puller Guide Removal Brake Shoe: Service and Repair Removal For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Exploded View 1. Raise and support vehicle, then remove tire and wheel assembly. 2. Remove brake drum. If brake lining is dragging on brake drum, back off brake adjustment by rotating adjustment screw. If brake drum is rusted or corroded to axle flange and cannot be removed, lightly tap axle flange to drum mounting surface with a suitable hammer. 3. Using brake spring pliers or equivalent, unhook primary and secondary return springs. Observe location of brake parts being removed to aid during installation. NOTE: For additional information see Brake Spring Removal and Installation Notes. See: Fundamentals and Basics 4. Remove brake hold-down springs with suitable tool. 5. Lift actuating lever, then unhook actuator link from anchor pin and remove. 6. Remove actuating lever and return spring. 7. Spread shoes apart and remove parking brake strut and spring. 8. Disconnect parking brake cable from lever, then remove brake shoes from backing plate. 9. Separate brake shoes by removing adjusting screw and spring, then unhook parking brake lever from shoe assembly. 10. Clean dirt from brake drum, backing plate and all other components. WARNING: Do not use compressed air or dry brush to clean brake parts. Many brake parts contain asbestos fibers which, if inhaled, can cause serious injury. Clean brake parts with a water soaked rag or a suitable vacuum cleaner to minimize airborne dust. Page 506 Door Switch: Locations Door Jamb Switch, LH Rear In LH B-Pillar Page 5877 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Page 5216 Symbol Identification Spark Plug Gap, Torque and Type Spark Plug: Specifications Spark Plug Gap, Torque and Type Spark Plug Gap ................................................................................................................................... ...................................................... 1.14 mm (.045 ") Spark Plug Torque ............................................................................................................................... ...................................................... 15 N-m (11 lb.ft.) Spark Plug Type .................................................................................................................................. ............................................................. AC CR43TS NOTE Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Page 5084 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 5241 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 2533 Manifold Pressure/Vacuum Sensor: Testing and Inspection Manifold Absolute Pressure Output Check Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures the changes in the intake manifold pressure which result from engine load (intake manifold vacuum) and rpm changes; and converts these into a voltage output. The control module sends a 5 volt reference voltage to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the control module knows the manifold pressure. At lower pressure output voltage will be about 1 to 2 volts. While at higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts.The MAP sensor is also used, under certain conditions, to measure barometric pressure, Page 1209 Page 5876 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These Page 424 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 1791 5. Replace the previous transmission mount with the revised mount (P/N 22145724 - for two wheel drive only) as shown in Figure 4. Some residual vibrations may be normal. Compare with a vehicle of same model, year, engine/transmission combination, etc. to get a feel for what is normal. SERVICE PARTS INFORMATION Parts are expected to be available from GMSPO on 8/2/93. WARRANTY INFORMATION Page 309 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 3549 Distributor: Service and Repair Distributor Shaft, Pole Piece & Pickup Coil Typical Distributor Components REMOVE/DISCONNECT 1. With distributor removed, disconnect wires at module terminals 2. Roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. INSTALL/CONNECT 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Page 1328 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Testing and Inspection Voltmeter Is Inaccurate Page 7740 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Bleeding Electronic Hydraulic Control Unit (EHCU) Module Hydraulic Assembly: Service and Repair Bleeding Electronic Hydraulic Control Unit (EHCU) Module Fig. 59 EHCU/BPMV Module Bleeding The EHCU Module should be bled after replacement or if trapped air is in the unit. If bleeding is required the module must be bled thoroughly before the wheel cylinders and calipers. There are two bleeders on top of the unit that appear to be normal bleeders, Fig. 59. These are modulator bleeders and must remain closed when the unit is not pressurized. The internal bleeders are on either side of EHCU module. The valves are used to open the internal passages within the EHCU module. Both bleed valves must be rotated 1/4 to 1/2 a turn counterclockwise before beginning the bleed process. The valve on the lefthand side is used for the rear brakes and the valve on the righthand side is used for the front brakes. The ignition switch must be in the ``Off'' position or false trouble codes may be stored. 1. Install combination valve depressor tool No. J 35836 or equivalent to LH high pressure accumulator bleed stem of EHCU module. 2. Install combination valve depressor tool No. J 35836 or equivalent to RH high pressure accumulator bleed stem of EHCU module. 3. Install combination valve depressor tool No. J 35836 or equivalent to rear combination valve. 4. Ensure master cylinder fluid level, fill if required. 5. Bleed EHCU module as follows: a. Slowly depress brake pedal one time and hold. b. Open left modulator bleeder, until fluid flows clearly or pedal is depressed, the close left bleeder. c. Slowly release brake pedal. d. Wait 15 seconds, then repeat a through d until all air is bled from EHCU module. e. Close LH internal bleed valve. Torque bleed valve to 60 inch lbs. f. Repeat steps b through e for RH bleed procedure. g. Remove three tool Nos. J 35856 or equivalents. 6. Ensure master cylinder fluid level, fill if required. 7. Bleed wheel cylinder and calipers. 8. Turn ignition key to ``On'' position, then perform 3 function test with TECH1 scanner. 9. Check brake pedal feel and braking performance, repeat procedure if required. Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: All Technical Service Bulletins Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 433 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 7395 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Diagram Information and Instructions Cruise Controller: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 6599 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 8468 Door Switch: Locations RH Front Door Jamb Switch In RH A-Pillar Page 5755 Suspension Strut / Shock Absorber: Specifications Shock Absorber Lower Mount 50 ft.lb Shock Absorber Upper Mount 15 ft.lb Page 4871 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7093 Paint: By Symptom Technical Service Bulletin # 231054R Date: 930701 Paint - Identification/Repair of Colorcoat Delamination BULLETIN NUMBER: 92-1O-134A SECTION: 10 Body NUMBER: 4 CORPORATE REFERENCE NUMBER: 231054R DATE: July 1993 SUBJECT: SERVICE PROCEDURES FOR IDENTIFICATION AND REPAIR OF PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER MODELS: 1988-92 TRUCKS THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 92-10-134 (CORP # 231054R), DATED OCTOBER 1992. IT IS BEING REVISED TO REMOVE THE COVER LETTER PORTION AND SUBJECT STATEMENT NOW INCLUDES NOTE FOR TRUCKS AND REVISES THE MONOCOAT MATERIAL ALLOWANCES ON "G", "S/T" AND SOME "R/V" MODELS. THE ALLOWANCE FOR "ADD FOR TWO-TONE" ON G AND S/T TRUCKS HAS BEEN CHANGED. ALL COPIES OF 92-10-134 SHOULD BE DISCARDED. The revisions are the result of changes to the MONOCOAT (ENAMEL) material allowance charts published in June, 1993. Six (6) of the "G" model revisions use Basecoat/Clearcoat material allowance codes. THESE ARE TO BE USED AS DOLLAR REFERENCES ONLY, AND ARE MARKED WITH A # INDICATOR. Continue to repair these vehicles with monocoat materials. DO NOT repair these vehicles with Basecoat/Clearcoat products. Use the latest (June, 1993) material allowance charts when submitting claims. SUBJECT: Service procedures for the repair of paint colorcoat delamination from elpo primer (repaint entire body above the body side moldings, except trucks as noted). APPLICATION: 1988-1992 LIGHT DUTY TRUCKS (C/K, R/V, S/T, M/L AND G) This bulletin cancels and supersedes service procedures and time allowances on all previous bulletins regarding paint DELAMINATION. Due to the use of new procedures, add times for optional equipment, and designating specific hardware items for removal, the published labor times will not be the same as previously published. CONDITION This bulletin is being issued to assure that the correct procedure is followed to repair a condition known as DELAMINATION. Some of the above listed passenger cars, light duty trucks, and vans may have DELAMINATION (peeling) of the paint color-coat from the ELPO primer depending upon variable factors including prolonged exposure to sunlight and humidity. Blues, Grays, Silvers and Black Metallics are the colors that have the highest potential for this condition. On rare occasions, other colors may be involved. Important DELAMINATION is different than other paint conditions and/or damage. A proper problem identification is necessary, and the service procedure that follows is specific to the proper repair of DELAMINATION and must be followed. The information in this bulletin covers Paint DELAMINATION of the colorcoat from the ELPO primer ONLY. It does not address any other paint conditions. Procedures for the repair of other paint conditions (stone chips, scratches, environmental damage, clearcoat peeling, runs, dirt, fading, etc.) will not effectively repair DELAMINATION and customer dissatisfaction will result. CAUSE This condition may occur on vehicles produced in plants where the paint process does not call for application of a primer surfacer. Under certain conditions, ultraviolet light can penetrate the colorcoat, sometimes causing a reaction and separation of portions of the colorcoat from the ELPO Page 7696 Audible Warning Device: Description and Operation Lamps-On Warning Buzzer When the Light Switch is in HEAD or PARK and the Panel Dimmer Switch is not at the dimmest setting, voltage is supplied through the INST LPS Fuse to the Audio Alarm Module through the GRA (8) wire. With the Panel Dimmer Switch at its dimmest setting, the current to the Audio Alarm module may not be enough to be sensed by the module. When the Ignition Switch is turned to RUN or START, voltage is supplied through the IGN/GAU Fuse and the Fuse Block SHUNT to the Module through the PNK/BLK (39) wire. These two voltages are sensed and the alarm is not sounded. When the Ignition Switch is turned to LOCK OFF or ACC, the IGN/GAU Fuse loses voltage. The Audio Alarm Module senses the change. If voltage is still available from the INST LPS Fuse, voltage from the STOP-HAZ Fuse is supplied to sound the alarm through the ORN (140) wire. The alarm can be turned off by turning the Light Switch off. The Module no longer senses voltage from the Light Switch, so the alarm does not sound. Page 6097 Blower Motor: Service and Repair Blower Motor Fan Replacement With A/C Push On Fan-Removal Procedure REMOVE OR DISCONNECT 1. Blower motor and fan assembly. 2. Using a hot knife, cut a slot in cage motor shaft sleeve in three places. Starting 12.7 mm (1/2-inch) from base of shaft, start cut from fan dome and continue to cut through the plastic material to the end of the shaft so that the fan splits from the shaft. 3. Fan cage from blower motor shaft by pulling straight out. Alternative Removal Methods 1. Using small wheel puller: - Remove tip of fan at end of motor shaft using soldering iron or cutting pliers. - Draw fan from motor shaft using a small puller. Hook legs of puller between fan lower rib and motor mounting plate. Thread center post of puller against the end of the motor shaft exposed in the above step. 2. Using drill press or arbor press: - Remove tip of fan at end of motor shaft using soldering iron or cutting pliers. - Support fan with blocks, angle iron, etc. while allowing the motor to be suspended (see accompanying figure). - Place steady pressure on tip of motor shaft, with a drill press or small arbor press and pin arrangement. Motor should fall freely from the fan after moving motor shaft about 12.7 mm (1/2-inch). NOTICE: Do not use force on motor to remove or install fan. Do not apply force to motor housing to seat fan on motor, or force motor/shaft bearing damage could result. Do not apply pressure to fan rim. Be sure correct replacement pen is used. Page 4693 Brake Drum: Service and Repair Installation Rear Drum Assembly Fig. 7 Measuring Brake Drum Inside Diameter Fig. 8 Adjusting Brake Shoes To Brake Drum Inside Diameter 1. If brake shoes have been replaced or the adjusting screw has been moved the shoes should be adjusted. To do this use a suitable brake drum to shoe gauge, measure brake drum inside diameter. Adjust brake shoes to dimension obtained on outside portion of gauge. 2. Install the brake drum. 3. Install the tire and wheel assembly 4. Lower vehicle. NOTE: For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Page 8363 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 5089 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Locations Dome Lamp Relay: Locations Part Of Rear Dome Lamp Assembly Locations License Lamps With Step Bumper Page 396 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 1076 Coolant: Technical Service Bulletins Coolant - Information on Propylene Glycol Usage File In Section: 6 - Engine Bulletin No.: 43-62-01B Date: April, 1995 Subject: Propylene Glycol Engine Coolant Models: 1994 and Prior Passenger Cars and Trucks This bulletin is being revised to reflect most current information on propylene glycol engine coolant. Please discard Corporate Bulletin Number 4362O1A (Group Reference 6 - Engine). General Motors has been reviewing data supplied on the performance of propylene glycol engine coolant in GM vehicles. It is our conclusion that propylene glycol engine coolant will perform adequately under most vehicle operating conditions. As a result, propylene glycol engine coolant (meeting performance specification GM 1825M) may be used in GM vehicles and will not affect the warranty coverage. Prior to adding propylene glycol engine coolant to the cooling system, all the existing (ethylene glycol) coolant must be removed. This can be accomplished either by utilizing water-based coolant flushing equipment or "waterless quick change" equipment available in the GMDE program. As with any coolant change procedure, be sure to thoroughly purge the heater core and block as well as the radiator before attempting to convert the system to propylene glycol coolant. Freeze/Boil point levels are different for propylene glycol than for ethylene glycol engine coolant. To accurately determine freeze/boil protection level, it is imperative that coolants not be mixed. Removing all the used coolant as previously discussed resolves this concern. Freeze protection of propylene glycol cannot be determined using a standard hydrometer. Rather, a refractometer or test strip must be used. Propylene glycol engine coolants may be recycled in the same manner as conventional ethylene glycol coolant. No adverse effects will be encountered if these coolants are mixed prior to recycling, however, the ratio of propylene glycol coolant to ethylene glycol coolant should be kept low to minimize the effects on freeze point measurements. Page 4588 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 5307 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 654 Oxygen Sensor: Service and Repair NOTE The Heated Oxygen Sensor (HO2S) uses a permanently attached pigtail and connector. This pigtail should not be removed from the Heated Oxygen Sensor (HO2S). Damage or removal of the pigtail or connector could affect proper operation of the oxygen sensor. Take care when handling the Heated Oxygen Sensor (HO2S). The in-line electrical connector and louvered end must be kept free of grease, dirt, or other contaminants. Also, avoid using cleaning solvents of any type. Do not drop or roughly handle the heated oxygen sensor. If the heated oxygen sensor pigtail wiring, connector or terminal is damaged, the entire oxygen sensor assembly must be replaced. Do not attempt to repair the wiring, connector or terminals. In order for the sensor to function properly, it must have provided to it a clean air reference. This clean air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors or terminals could result in the obstruction of the air reference and degraded oxygen sensor performance. CAUTION The following guidelines should be used when servicing the heated oxygen sensor: ^ Do not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor causing poor performance. Also, the sensor pigtail and harness wires must not be damaged in such a way that the wires inside are exposed. This could provide a path for foreign materials to enter the sensor and cause performance problems. ^ Neither the sensor or vehicle lead wires should be bent sharply or kinked. Sharp bends, kinks, etc., could block the reference air path through the lead wire. ^ Do not remove or defeat the oxygen sensor ground wire (where applicable). Vehicles that utilize the ground wired sensor may rely on this ground as the only ground contact to the sensor. Removal of the ground wire will also cause poor engine performance. ^ The Heated Oxygen Sensor (HO2S) may be difficult to remove, when engine temperature is below 48°C (120°F). Excessive force may damage threads in exhaust manifold or exhaust pipe. NOTE The engine harness may be repaired using Packard's Crimp and Splice Seals Terminal Repair Kit J 38125-A. Under no circumstances should repairs be soldered since this could result in the air reference being obstructed. Remove or Disconnect 1. Negative battery cable. 2. Electrical connector releasing locking tab. 3. Carefully back out oxygen sensor. Install or Connect NOTE A special anti-seize compound is used on the Heated Oxygen Sensor (HO2S) threads. The compound consists of liquid graphite and glass beads. The graphite will tend to burn away, but the glass beads will remain, making the sensor easier to remove. New, or service replacement sensors will already have the compound applied to the threads. If a sensor is removed from an engine, and if for any reason it is to be reinstalled, the threads must have anti-seize compound applied before reinstallation. 1. Coat threads of heated oxygen sensor with anti-seize compound (GM PIN 5613695 or equivalent), if necessary. 2. Sensor, and torque to 41 Nm (30 ib. ft.). 3. Electrical connector. 4. Negative battery cable. Page 4237 b. Rotate drive pinion one revolution and check gear tooth contact pattern as shown on Fig. 4. Add or remove shims as required. c. After backlash and tooth pattern operation has been completed, remove shim packs using caution not to mix them. d. Select new shims for each side .004 inch thicker than those removed, then install each shim on its proper side. This additional thickness will ensure proper bearing preload. e. Check total rotational torque. Total torque with differential case preloaded and pinion installed should be 16---29 inch lbs. if new bearings are installed or 10---16 inch lbs. if original bearings are installed. f. If total rotational torque is not as specified, repeat steps 4 through 10. 11. If drive pinion was removed, remove differential case and shims, then proceed to ``Drive Pinion & Bearing Shim Adjustment'' procedure. Page 1695 Crankshaft Main Bearing: Service and Repair Main bearings are available in standard size and undersizes of .001, .002, .009, .010 and .020 inch. Connecting rod bearings are available in standard size and .001 and .002 inch undersize for use with new and used standard size crankshafts and .010 and .020 inch undersize for use with reconditioned crankshafts. Page 6609 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Locations Turn And Hazard Lamp Flashers Page 3073 Vehicle Speed Sensor Signal Buffer: Symptom Related Diagnostic Procedures Cruise Control Does Not Operate Properly Seat Belt - Operations/Features and Location Seat Belt: Technical Service Bulletins Seat Belt - Operations/Features and Location FILE IN SECTION: 10 - Body BULLETIN NO.: 56-16-01 DATE: April, 1995 SUBJECT:Seat Belt Operation, Features and Location MODELS: 1988-95 Chevrolet and GMC Truck C/K Pickups 1983-95 Chevrolet and GMC Truck S/T Models The following passenger seat belts operate differently from the comparable driver's seat belt. 1. Right front passenger seat belts (Figure 1, Position 1) on: 1988-95 C/K Pickups 1992-95 C/K Crew Cabs 1983-95 S/T Pickups and Utilities 2. Left and right rear second seat outboard belts (Figure 1, Position 2) on: 1992-95 C/K Crew Cabs 1995 S/T Utilities The reason for the difference is to allow a child restraint (child seat) to be used in these passenger positions. Child restraints require the lap portion of the seat belt to firmly tighten around the restraint. To accommodate this requirement, belts in the aforementioned positions are equipped with a ratcheting feature activated by pulling the lap belt all the way out. Once the belt has been pulled all the way out, it becomes a one way mechanism that will retract until it contacts a solid object like a child restraint or person, but will not extend again until it has been fully retracted all the way back to the stop button attached to the belt. This feature is often referred to as a child hold out mechanism. If a passenger finds that the belt becomes tight and uncomfortable while riding, it may indicate that the belt was pulled all the way out during the buckling process, thus activating the racheting feature. This condition can be avoided by taking care not to pull the belt to its very end when buckling up. Locations Engine Wiring, LH Side Page 3759 PROM - Programmable Read Only Memory: Testing and Inspection Some control modules may have problems due to cracked solder joints on the circuit board. These internal control module problems can cause the following symptoms: ^ Failure to start or vehicle is stalling. ^ The "CHECK ENGINE" "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR" light will flash or light up, but no trouble codes will be present. ^ Vehicle instrument panel displays may be inoperative. ^ The control module may or may not communicate with the scanner. ^ Other intermittent driveability problems. Incorrect PROM or MEMCAL removal and replacement can create solder joint problems or aggravate an existing condition. See PROM or MEMCAL INSTALLATION for proper procedures. If a solder joint problem results in a "hard" failure, normal test procedures will usually pinpoint a faulty control module. Many symptoms caused by poor solder joints in the control module result in intermittent problems, but they may be hard to duplicate during troubleshooting. Control modules with solder joint problems are sensitive to heat and vibration. You can check for these internal control module problems in either, or both, of the following ways: ^ Remove the control module from its mounting bracket and extend it on the harness so that you can expose it to the vehicle heater ducts. Alternatively, use the flexible duct to route air from the heater to the control module location. Then run the engine and operate the heater at the "MAX HEAT" position. This exposes the control module to approximately 140°F. ^ With the engine running, tap on the control module several times with your hand or finger tips to simulate vehicle vibration. If the engine stumbles or stalls, the "CHECK ENGINE" "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR" light flashes, or any of the previous symptoms occur, the control module may have bad solder joints on the circuit board. Inline Fuse, Trailer Towing Harness Fuse: Locations Inline Fuse, Trailer Towing Harness Center Of Dash Panel, In Engine Compartment Page 5036 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Saginaw Rack & Pinion Gear Steering Gear: Description and Operation Saginaw Rack & Pinion Gear Fig. 1 Exploded view of rack & pinion gear The power rack and pinion steering system, Fig. 1, has a rotary control valve which directs hydraulic fluid coming from the pump to one or the other side of the rack piston. The piston is attached to the rack. The piston converts hydraulic pressure to a linear force which moves the rack left or right. The force is then transmitted through the inner and outer tie rods to the steering knuckles, which turn the wheels. If hydraulic assist is not available, manual control is maintained, however more steering effort is required. The movement of the steering wheel is transferred to the pinion. The movement of the pinion is transferred through the pinion teeth, which mesh with teeth on the rack, causing the rack to move. Coolant Temperature Switch Engine Wiring, LH Side Page 4021 Throttle Valve Cable/Linkage: Adjustments TV Cable Fig. 4 Typical TV Cable Adjuster Fig. 5 TV Cable Adjustment. Models W/V6 And V8 Gasoline Engines Except Astro, Safari & S/T-10/15 Page 699 Vehicle Speed Sensor: Service and Repair 1. Disconnect vehicle speed sensor electrical connector. 2. Remove sensor attaching bolt. 3. Using speed sensor remover and installer, tool No. J 38417, remove sensor, then O-ring seal. 4. Reverse procedure to install, coating the new O-ring seal with transmission fluid. Torque attaching bolt to 97 inch lbs. Page 6330 Expansion Block/Orifice Tube: Service and Repair Fitting And Hose Installation Evaporator And Blower Assembly Component View Removal & Installation Distributor: Service and Repair Removal & Installation Distributor And Coil 4.3L Engine REMOVE/DISCONNECT NOTE Verify ignition switch is "OFF". 1. Wiring harness connectors at side of distributor. 2. Coil wire and sparkplug wires on either left or right side of distributor. 3. Distributor cap by two screws and set to side: - Bring engine to TDC on the compression stroke for #1 cylinder and align timing marks to 0~ . Scribe a mark on distributor housing in line with rotor. - Scribe a mark on engine in line with rotor. Note position of distributor housing in relation to engine. 4. Remove distributor bolt hold-down clamp, raise distributor noting rotor rotation, then remove distributor and gasket (if applicable). Do not rotate crankshaft with distributor removed from engine. INSTALL/CONNECT NOTE To ensure correct timing of distributor it must be installed with rotor correctly positioned as noted in Step 3 of the removal procedure. Line up rotor, mark on distributor housing, and mark on engine. If distributor shaft won't drop into engine, insert a screwdriver into cavity for distributor and turn oil pump driveshaft. 1. Distributor and gasket (if applicable). 2. Hold-down clamp and tighten bolt to 34 Nm (25 lb. ft.). 3. Distributor cap. 4. Wiring harness connectors at side of distributor. 5. Sparkplug wires and coil wires. 6. Check engine timing. Tires - Manufacturers' Assistance Tires: All Technical Service Bulletins Tires - Manufacturers' Assistance Group Ref.: Steering/ Suspension Bulletin No.: 323501 Date: December, 1993 INFORMATION SUBJECT: TIRE MANUFACTURERS' CONTACTS FOR ASSISTANCE MODELS: 1991-94 PASSENGER CARS AND TRUCKS General Tire has established a "Tire Fix" Department to assist you with anything from a tire adjustment to the location of the nearest General Tire dealer. "Tire Fix" representatives are available Monday through Friday from 8:00 A.M. to 6:00 P.M. Eastern Time at 1-800-847-3349. A General Tire Brochure is provided for review with all appropriate dealer personnel. A single contact point at General Tire can assist you with most aspects of their product to satisfy your customers' needs. Other tire manufacturers can be contacted for assistance at the Toll Free Numbers listed in illustration: Please retain this information for future reference. Page 5034 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 3010 Speed Sensor And Backup Lamp Switch Wiring - Two-Wheel Drive Models Page 4826 Fig. 6 Spool Valve, Power Piston/Accumulator & Seal, Assembly & Disassembly Refer to Figs. 5 and 6 for disassembly and assembly of Hydro-Boost II unit. or accumulator service, refer to HYRO-BOOST ACCUMULATOR. CLEANING/INSPECTION Keep all disassembled parts clean until assembly. Lubricate all seals and metal friction points with power steering fluid. When unit is disassembled, all seals and tube inserts should be replaced. These parts are available in replacement kits. If any accumulator valve components are damaged or lost, replace all valve components. 1. Inspect spool valve and spool valve bore for corrosion, nicks, scoring or other damage. Discoloration of the spool or bore, particularly in the groove areas, is not harmful and replacement is not necessary. 2. If spool valve or bore has nicks or scoring that can be felt with a fingernail, the entire booster should be replaced as an assembly. The clearance between the spool valve and the spool valve bore is important. Because of this clearance, the spool valve and the housing make up a selective assembly. The spool valve is selected to match the spool valve bore. 3. Inspect piston for scratches and nicks. If scratches on the outside surface can be felt with a fingernail, replace piston. Page 7370 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 6233 1. Install the shaft key into the hub key groove (Fig. 7). Allow the key to project approximately 4.8mm (3/16") out of the keyway. The shaft key is curved slightly to provide an interference fit in the shaft key groove of the hub. 2. Be sure the frictional surface of the clutch plate and the clutch rotor are clean before installing the Clutch Plate and Hub assembly. 3. Align the shaft key with the shaft keyway and place the Clutch Plate and Hub assembly Onto the compressor shaft. NOTICE: To avoid internal damage to the compressor, do not drive or pound on the clutch hub or shaft. 4. Install the Clutch Plate and Hub Installer J 9401-B as illustrated in Figure 8. 5. Hold the hex portion of the Installer Body J 9401-B with a wrench and tighten the center screw to press the hub onto the shaft until there is a 0.5-7.6mm (0.20-0.30") air gap between the frictional surfaces of the clutch plate and clutch rotor. 6. Install a new shaft nut with the small diameter boss of the nut against the crankshaft shoulder, using Thin Wall Socket J 9399-A. Hold the Clutch Plate and Hub assembly with Clutch Hub Holding Tool J 33027-A, and tighten to 14 N.m (10 lb.ft.) torque, using a 0-60 N.m (0-25 lb.ft.) torque wrench. 7. If operation is performed with compressor on vehicle, connect drive belt, tighten mounting brackets and adjust belt tension. Spark Plug Gap, Torque and Type Spark Plug: Specifications Spark Plug Gap, Torque and Type Spark Plug Gap ................................................................................................................................... ...................................................... 1.14 mm (.045 ") Spark Plug Torque ............................................................................................................................... ...................................................... 15 N-m (11 lb.ft.) Spark Plug Type .................................................................................................................................. ............................................................. AC CR43TS NOTE Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Page 7608 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 1673 21. Timing chain, camshaft sprocket, and balance shaft drive gear. 22. Balance shaft driven gear. 23. Balance shaft retainer. 24. Intake manifold, as outlined in this section. 25. Lifter retainer. 26. Balance shaft and front bearing using a soft faced hammer. Page 1578 II. OVER TORQUING OF WHEEL NUTS: 1. A TORQUE WRENCH MUST BE USED to insure that the wheel nuts are tightened to specification. This should be done in two steps using the star pattern. First, snug the nuts down by hand. Then, using the star pattern and a torque wrench, tighten the wheel nuts to about half the final torque. Finally, tighten the wheel nuts to specification using the star pattern and a torque wrench. 2. NEVER use lubricants or penetrating fluids on wheel studs, nuts, or mounting surfaces, as this can raise the actual torque on the nut without a corresponding torque reading on the wrench. Wheel nuts, studs, and mounting surfaces must be clean and dry. Page 6245 Clean The inside of the compressor around the shaft (38). Prevent dust and dirt from entering compressor. 2. Sleeve retainer (10). 3. Absorbent felt sleeve (11). Removing/Installing The Shaft Seal Seat Retaining Ring 4. Shaft seal seat retaining ring (12) with J 5403. Removing/Installing The Shaft Seal Seat And O-Ring 5. Shaft seal seat (13). - Engage J 23128-A into the recessed portion of the seat by turning to the right (clockwise). - Lift the seat (13) from the compressor with a rotary motion. Page 5441 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 6439 Important: All of the following parts are NOT NEEDED for a normal retrofit. Follow the bulletin procedures to determine which parts you need! Individual vehicle kits are not necessary, since most of the parts are generic and only a few parts are needed for most vehicles. GEO Parts are listed in "Platform Details." Parts are currently available from GMSPO. D. Warranty Information 1. Vehicle Still Within the Original New Vehicle Limited Warranty Period When GM models for the years listed in the bulletin require repairs to the refrigerant system and the vehicles are still covered under the New Body - Maintaining Exterior Weatherstrip Appearance Weatherstrip: Technical Service Bulletins Body - Maintaining Exterior Weatherstrip Appearance INFORMATION Bulletin No.: 99-08-64-016C Date: July 29, 2009 Subject: Information on Maintaining Exterior Weatherstrip Appearance Models: 2010 and Prior Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and update the parts and procedure information. Please discard Corporate Bulletin Number 99-08-64-016B (Section 08 - Body and Accessories). Exterior weatherstrips are exposed to a variety of environmental elements, including UV rays, acid rain, insect and bird residue and atmospheric fallout. All of these may effect the appearance of the weatherstrips; however, they do not effect the functionality of the weatherstrip. Weatherstrips that are discolored should not be replaced under the normal GM New Vehicle Warranty. Weatherstrip Maintenance Instructions Silicone grease on weatherstrips will make them last longer, seal better, and not stick or squeak. Clean the weatherstrips with a mild soap and water solution. Apply silicone grease with a clean cloth. During very cold, damp weather, frequent application may be required. Refer to the information below for the recommended maintenance products. Weatherstrips that are not maintained may crack and weather due to environmental elements. Parts Information Weatherstrip Conditioning Weatherstrip Lubricant (GM P/N 3634770 [in Canada, P/N 10953518]) or Dielectric Silicone Grease (GM P/N 12345579 [in Canada, P/N 992887]). Disclaimer Page 5279 Relay Box: Electrical Diagrams Convenience Center (without Digital Cluster) Page 5032 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 7004 Important: Before using the tester and the diagnostic chart, the following two steps must be performed. 1. Verify that the keyless entry transmitter is the correct model for the vehicle remote system. An incorrect model transmitter may pass this test, but may not activate the vehicle remote system. The correct transmitter can usually be identified by part number. 2. Ensure that the transmitter is synchronized with the vehicle (if applicable). Refer to Transmitter Synchronization in the appropriate Service Manual. Page 6998 Disclaimer Page 1907 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. With A-6 Compressor Compressor Clutch Hub: Service and Repair With A-6 Compressor Remove or Disconnect Tools Required: J 9396 Compressor Holding Fixture J 9399-A Compressor Shaft Nut Socket J 9401-B Hub Drive Plate Remove J 25030-A Clutch Hub Holding Tool - Clamp J 9396 in a vise. Page 5228 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 7536 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Page 6252 Compressor Shaft Seal: Service and Repair With HR100T/HR110T Compressor Shaft Seal Design The shaft seal is a lip seal, one piece design. Seal Leak Detection A shaft seal should not be changed because of an oil-line on the hood insulator. Only change a shaft seal when a leak is detected by evidence of oil sprayed in large amounts and then only after actual refrigerant leakage is found by using an approved leak Detector such as 3 29547 or equivalent. On-Vehicle Remove or Disconnect 1. Recover Refrigerant. 2. Loosen and reposition compressor in mounting brackets, if necessary. 3. Remove Clutch Plate and Hub assembly from compressor. 4. Remove the shaft seal seat retainer ring, using Snap Ring Pliers J 5403. 5. Thoroughly clean inside of compressor neck area and O-ring groove surrounding the shaft, the exposed portion of the seal seat and the shaft itself. Any dirt or foreign material getting into compressor may cause damage. 6. Remove Lip Seal: Page 8275 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 2837 Malfunction Indicator Lamp: Description and Operation PURPOSE The Malfunction Indicator Lamp (MIL), "Service Engine Soon" light has the following purposes: Inform the driver that a problem has occurred, and that the vehicle should be taken for service as soon as reasonably possible. - Displays Diagnostic Trouble Codes (DTC) stored by the ECM helping the technician diagnose system faults. - Indicates "Open Loop" or "Closed Loop" operation. OPERATION The MIL will come "ON" with the key "ON" and the engine not running. When the engine is started, the light will turn "OFF.". This is a bulb and system check. If the light remains "ON," the self-diagnostic system has detected a problem. If the problem goes away, the light will go out in most cases after 10 seconds, but a DTC will remain stored in the ECM. Page 6428 Page 3490 Throttle Cable/Linkage: Locations Accelerator Pedal Assembly PEDAL ASSEMBLY Accelerator Cable CMFI LINKAGE Page 1280 Symbol Identification Page 6135 Install or Connect Tools Required: J 9399-A Compressor Shaft Nut Socket J 9401-A Hub and Drive Plate Assembly Installer J 25030-A Clutch Hub Holding Tool 1. Shaft key (36). Aligning The Drive Plate Key - Allow the shaft key (36) to extend 4.5 mm (3/16-inch) out of the bottom of the hub keyway. - The shaft key (36) is curved to give an interference fit in the groove. Important - Do not drive or pound or the clutch hub or the shaft (39). Internal damage to the compressor may result. 2. Clutch plate and hub assembly (2). - Install the clutch plate and hub assembly (2) over the compressor shaft lining up the key slot on the hub with the keyway slot in the shaft. Page 8707 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Locations Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Page 3061 Chart 6 Vehicle Speed Sensor Test Page 8199 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 6836 Page 7693 Audio Alarms Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Page 4347 Axle Shaft Assembly: Description and Operation Rockwell Full Floating Rockwell axle w/12 inch ring gear This axle, Fig. 13, employs a heavy duty hypoid drive pinion and ring gear. The differential and gear assembly is mounted on tapered roller bearings. The straddle mounted pinion has two tapered roller bearings in front of the pinion teeth which take the forward and reverse thrust, while a third bearing behind the pinion teeth carries the radial load. Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Page 7496 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 5109 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 388 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Coolant Temperature Switch Engine Wiring, LH Side Page 6847 Front Door Trim Panel Components Tools Page 7616 Symbol Identification Page 7244 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 4941 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 5838 ^ Always inspect and adjust the pressure when the tires are cold. ^ Vehicles that have different pressures for the front and the rear need to be adjusted after tire rotation. Improper tire inflation may result in any or all of the following conditions: ^ Premature tire wear ^ Harsh ride ^ Excessive road noise ^ Poor handling ^ Reduced fuel economy ^ Low Tire Pressure Monitor (TPM) Light ON ^ Low Tire Pressure Message on the Drivers Information Center (DIC) Disclaimer Page 4824 CLEANING/INSPECTION Fig. 4 Spool valve inspection 1. Clean all parts in a suitable solvent being careful to avoid losing small parts. 2. Inspect valve spool and valve spool bore in booster housing for corrosion, nicks, scoring or other damage. Discoloration of the spool or bore, particularly in the grooves, is not harmful. 3. If the valve spool or the spool bore has nicks or scoring that can be felt with a fingernail, particularly on the hands, the spool and housing should be replaced as an assembly, Fig. 4. The clearance between the valve spool and the spool bore of the housing is important. Because of this, the spool and housing make are made as a selective assembly and therefore can only be replaced as an assembly. 4. Inspect the input rod and piston assembly for corrosion, nicks, scoring or excessive wear. If the piston is damaged, the input rod and piston assembly should be replaced. 5. Inspect piston bore in booster housing for corrosion, nicks, scoring or other damage. If the bore is damaged, the valve spool and housing should be replaced as an assembly. ASSEMBLY Lubricate all the seals and metal friction points with power steering fluid. 1. Install return line seal, then the fitting Fig. 3. 2. Install accumulator valve and spool valve into housing. 3. Install seal on piston assembly using seal protector tool No. J-25083 or equivalent. 4. Install seal onto the housing, then install cover and bolts. Torque housing bolts to 22 ft. lbs. 5. Install bracket and nut, then torque to 110 ft. lbs. 6. Install boot, output pushrod, baffle, piston return spring, and retainer using seal protector tool No. 2455l or equivalent. 7. Install retainer, spring, O-ring, and plug, using accumulator compressor tool No. J-26889 or equivalent, and C-clamp. 8. Depress the accumulator, then install the retainer and remove C-clamp. 9. Jam nut from the repair kit onto pedal rod, and install eyelet onto pedal rod. 10. Adjust eyelet to required length. Hydro-Boost II Assembly DISASSEMBLY/ASSEMBLY Page 6220 Compressor Clutch Hub: Specifications With HR6-HE Compressor Clutch Plate & Rotor .............................................................................................................................................................. 0.50-0.76mm (0.020-0.030") Page 4591 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 7322 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7622 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 3659 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Diagram Information and Instructions Antilock Brake Module: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 8454 Brake Light Switch: Adjustments Fig. 2 Stop Light Switch Installation 1. Disconnect battery ground cable. 2. Disconnect wiring connector from brake light switch located on brake pedal bracket. 3. Pull switch from mounting bracket. 4. Depress brake pedal, then push new switch into clip until shoulder bottoms out, Fig. 2. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed .53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Page 5572 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Level Sending Unit: All Technical Service Bulletins Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 2968 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION - Connectors and wires - Housing and insulator for cracks/damage - Sensor tip for silicone contamination (white powdery coating) CAUTION Do NOT perform the following test for more than 2 minutes, as this may cause damage to the catalytic converter. PERFORMANCE TEST Checks working range and response (speed). Warm engine - Install DVOM between sensor and ground (2 volt D.C. range) - "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). - Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. - Drive system lean: Create a vacuum leak from a source that is not an control module input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE After each test the O2 sensor should return to normal operating range within two to three seconds. - O2 Sensor should be replaced for failure to pass any of the tests above. NOTE A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. - Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. HEATING ELEMENT (H20S only) - Turn ignition "OFF". Disconnect electrical connector. - Connect test light between harness terminals "A" and "B". - Turn ignition "ON". Test light should be "ON". If test light is "OFF", connect test light to harness terminal "A" to ground. Light should be "ON" ensuring power circuit is operating correctly. - Turn ignition "OFF". - Using an ohmmeter, measure resistance between terminals A and B. Resistance @ Specified Temperature 3.5 ohms @ 20°C (68°F) 14 ohms @ 350°C (662°F) Front Caster and Camber Adjustment Alignment: Service and Repair Front Caster and Camber Adjustment Fig. 1 Caster & Camber Adjustment. 4 X 2 Models Before checking or adjusting caster and camber angles, jounce vehicle at least 3 times to prevent false geometric readings. 4 X 2 MODELS Caster and camber adjustments are made by shims inserted between upper control arm shaft and frame bracket, Fig. 1. Add, subtract, or transfer shims to change readings as noted below. To adjust caster and/or camber, loosen upper control arm shaft to frame nuts, then add or subtract shims as necessary and torque upper control arm shaft to frame nuts to specification. Caster Transfer shims from front to rear, or rear to front. The transfer of one shim from rear to front bolt will decrease positive caster. Camber Change shims at both front and rear of shaft. Adding an equal amount of shims at both front and rear locations will decrease positive camber. After adjustment, the shim pack should have at least two threads of bolt exposed beyond the nut. The difference between front and rear shim packs must not exceed 0.40 inches. 4 X 4 MODELS Caster and camber adjustments are made by cam mounted upper control arm attaching bolts. To adjust caster and/or camber, loosen upper control arm to frame attaching bolt nut, then rotate cam by turning bolt head. Caster To increase positive caster, move front cam lobe inward and rear cam lobe outward. Camber To increase positive camber, move both front and rear cam lobes inward. When proper alignment settings are established, torque upper control arm to frame attaching bolt nut to specification. Page 7183 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 3412 For vehicles repaired under warranty use: Page 3317 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Page 8002 Door Switch: Locations Door Jamb Switch, LH Rear In LH B-Pillar Page 5471 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 2817 Idle Speed/Throttle Actuator - Electronic: Description and Operation Idle Air Control (IAC) System IAC Valve IAC System PURPOSE To control engine idle speed and prevent stalling due to changes in engine load. OPERATION All engine idle speeds are controlled by the control module through the Idle Air Control (IAC) valve mounted on the throttle body. The control module sends voltage pulses to the IAC motor windings causing the IAC motor shaft and pintle to move "IN" or "OUT" a given distance (number of steps) for each pulse (called counts). Inward movement of the pintle = Decreased RPM =Lower Counts. Outward movement of the pintle = Increased RPM = Higher Counts. This movement controls airflow around the throttle plate, which in turn, controls engine idle speed, either cold or hot. IAC valve pintle position counts can be seen using a Tech 1 scan tool. Zero (0) counts correspond to a fully closed passage, while 140 counts or more (depending on the application) corresponds to full flow. - Actual or "controlled" idle speed is obtained by the control module positioning the IAC valve pintle. Resulting idle speed is generated from the total Page 4550 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 5448 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 8025 Fuel Gauge Sender: Testing and Inspection Diagnostic Circuit Check Odometer/Speedometer - ACDelco Service Center Locations Speedometer Head: All Technical Service Bulletins Odometer/Speedometer - ACDelco Service Center Locations File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-04A Date: September, 1996 INFORMATION Subject: AC Delco Service Center Locations for Odometer/Speedometer Service Models: 1997 and Prior Passenger Cars and Trucks (excluding Cadillac) This bulletin is being revised to provide the necessary contact information only. Please discard Corporate Bulletin Number 66-83-04 (Section 8 - Chassis/Body Electrical) General Motors provides service for sophisticated electronic products through the authorized AC Delco Service Center Program. This program is designed to provide GM vehicle owners with the highest quality and most technically up-to-date product available. Repair products from unauthorized service outlets are not acceptable as warranty replacements. Currently, there are 25 authorized AC Delco Service Centers who exchange and remanufacture odometer/speedometers (list included). Only these Centers should be contacted for service. Important: W series and 1997 T series Medium Duty truck odometer/speedometers must be ordered directly from GMSPO. The following steps should be taken when utilizing the AC Delco Service Centers: Dealers should contact their local AC Delco Service Center (list included). Any listed facility may be used. The following information must be provided: Part number VIN, Mileage, Vehicle Year, Make and Model Dealer Name and Address Delivery Date of Vehicle Name of the person requesting exchange or service Phone number Repair Order Number P.O. number (if non - warranty) Vehicle Ride (Trim) Height Specifications Alignment: Specifications Vehicle Ride (Trim) Height Specifications Fig. 3 Vehicle Riding Height Measurement Locations & Specifications. 4 X 2 Models 4 X 2 MODELS Refer to Fig. 3, for ride height measurements and specifications. Fig. 4 Vehicle Riding Height Measurement Locations & Specifications. 4 X 4 Models 4 X 4 MODELS Refer to Fig. 4, for ride height measurements and specifications. Page 6004 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Page 5478 CAUTION: Fusible links cut longer than 225 mm (approx 9 in.) will not provide sufficient overload protection. Fig. 4 Single Wire Feed Fusible Link Fig. 5 Double Wire Feed Fusible Link To replace a damaged fusible link, Fig. 4, cut it off beyond the splice. Replace with a repair link. When connecting the repair link, strip wire and use staking-type pliers to crimp the splice securely in two places. For more details on splicing procedures, see Diagnostic Aids/Connector and Wire Repair. Use Crimp and Seal splices whenever possible. To replace a damaged fusible link which feeds two harness wires, cut them both off beyond the splice. Use two repair links, one spliced to each harness wire, Fig. 5. Typical Electrical Repair TYPICAL ELECTRICAL REPAIR An open circuit is an incomplete circuit. Power cannot reach the load or reach ground. If a circuit is open, active components do not energize. A short circuit is an unwanted connection between one part of the circuit and either ground or another part of the circuit. A short circuit causes a fuse to blow or a circuit breaker to open. SHORT CIRCUITS CAUSED BY DAMAGED WIRE INSULATION ^ Locate the damaged wire. ^ Find and correct the cause of the wire insulation damage. ^ For minor damage, tape over the wire. If damage is more extensive, replace the faulty segment of the wire. Splicing Copper Wire Using Splice Clips The Splice Clip (included in the GM J 38125-A Terminal Repair Kit) is a general purpose wire repair device. It may not be acceptable for applications having special requirements such as moisture sealing. Page 2225 IMPORTANT: To maintain a balanced fan assembly, align the yellow paint mark on the fan clutch with the yellow paint mark on the water pump hub. SERVICE PARTS INFORMATION Part Number Description 15672779 Fan Clutch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Page 2342 5. Transmission fluid cooler pipes. 6. Engine oil cooler pipes. 7. Radiator. Install or Connect 1. Radiator. 2. Engine oil cooler line fittings. Tighten Fittings to 35 N.m (25 ft. lbs.). Locations Oil Pressure Switch (For Fuel Pump): Locations Rear Of Engine Oil Pressure Switch 4.3L Utility Page 437 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 3060 - Cruise control - ANTILOCK brake system. CONSTRUCTION The VSS is made up of: Permanent Magnet (PM) generator (coil), which is mounted on the transmission. - Rotor (tooth), which is mounted on the output shaft in the transmission. - VSS Buffer, which is mounted to the control module bracket. OPERATION The VSS is a Permanent Magnet (PM) generator that produces a pulsing Alternating Current (AC) voltage as each rotor tooth nears the coil. As the vehicle speed increases, the number of AC voltage pulses increase. The VSS buffer processes inputs from the VSS and outputs signal to the speedometer control module and cruise module. The VSS buffer takes the voltage pulses from the VSS and uses them to open and close four solid state output switches to ground at a rate proportional to vehicle speed. The VSS buffer is matched to the vehicle based on final drive ratio and tire size. Page 1799 - Adjust converter to center the mounting pins in the insulators. This equalizes the hanger load at the insulators (Figure 2). - Move U-bolt back to original position and tighten. 3. Settle the powertrain by shifting from DRIVE to REVERSE with automatic transmission or 1ST to REVERSE with manual transmission, at least three times with engine at idle. Then turn engine off. 4. Tighten all fasteners with the powertrain in a relaxed position (vehicle in neutral). Torque to specifications in Service Manual X-9129. Note: Be sure that the catalytic converter hanger and hanger pins are centered in the insulators, the pins should have 6.0-16.0 mm (1/4 in. - 5/8 in.) clearance as shown in Figure 2. Page 4836 Vacuum Brake Booster: Description and Operation Tandem Diaphragm Type Fig. 6 Exploded View Of Delco-Moraine Tandem Power Brake Unit Fig. 7 Exploded View Of Delco-Moraine Tandem Diaphragm Power Piston Assembly These units, Figs. 6 and 7, have a vacuum power chamber that consists of a front and rear shell, a housing divider, front and rear diaphragm and plate assemblies, an hydraulic pushrod and a diaphragm return spring. The unit operates in much the same manner as the Single Diaphragm unit described above. The diaphragm and plate assemblies use the pressure differential created by engine intake manifold vacuum and atmospheric pressure to assist the hydraulic pushrod. Locations Power Steering Pressure Switch Wiring Page 6424 Use the octagon sockets on the straight fittings (J 39037 high side, and J 41256 low side). Torque the new fitting until it seats. The fitting should seat fully BEFORE reaching 11 N.m (8 lb ft). If 11 N.m (8 lb ft) of torque is reached and the fitting has not seated, it is probable that the threads have been damaged. In this case, remove the fitting and use the thread restorer listed above. Reinstall the fitting, adding one drop of a thread locking compound such as Loctite(R) 242. The fittings (except the two-piece) have a thread locking compound applied to the threads. This compound will set up enough to restrict removal of the fitting in about 15 minutes. The fittings can now be used to evacuate the system (see Step 5). An additional type of conversion port fitting has been developed. This fitting is called a saddle clamp valve (see Figure 5). It can be clamped directly on a metal refrigerant line, and will be used if the existing fitting is damaged or is inaccessible. A drop of a thread locking compound, such as Loctite(R) 242, should be used on each bolt to prevent the threads from loosening. The R134a saddle clamp valve part numbers are: If an existing R-12 service port is not used, it must be rendered inoperative. Place several drops of a thread locking compound, such as Loctite(R) 243, in the valve core, and onto the cap threads. Secure the cap and let it set for 15 minutes. 4. Install Any Additional Parts Needed See "Platform Details" after Step 6. If a vehicle is listed as a "Basic Retrofit", no additional parts are required (except for compressors, see the Compressor Replacement Chart at the beginning of Platform Details). If no parts are required, PROCEED TO STEP 5. Compressors Compressors do not need to be replaced as part of a normal retrofit, unless indicated in the Compressor Replacement Chart. An R-12 compressor that is operating properly can, in most cases, be left in the vehicle when it is retrofitted to R134a. However, if a compressor failure is the reason the vehicle is in for service, and the vehicle will be retrofitted, OR if a vehicle has already been retrofitted with R-134a and the compressor fails at some time in the future, new compressors for use with R-134a are available. See the GMSPO Parts Catalog for specific part numbers. DO NOT use a replacement R-12 compressor for any vehicle retrofitted to R-134a (unless it is the new "oil-less" design). See "Compressor Availability" at the end of the Compressor Replacement Chart. Accumulator /Dryer If the vehicle is more than 5 years old, the Accumulator/Dryer (A/D) should be replaced to ensure that moisture is removed from the system. See the instructions for proper A/D identification in General Information. High Pressure Cut-Off Switch (HPCOS) Most trucks, and some 1984-93 B and D cars, require that a HPCOS be added to protect the refrigerant system during long idles at high temperature. The HPCOS kit (P/N 15981985) contains the switch, wire harness, heat sealing splice connectors, switch "0" ring, and installation instructions. A saddle clamp adapter (P/N 15985307), or a special dual fitting, is mounted to the high pressure line, and provides the port to mount the switch. A drop of a Page 6137 Remove or Disconnect Tools Required: J 6435 External Snap Ring Pliers J 8092 Driver Handle J 8433 Heavy Duty Pulley Puller J 9395 Pulley Puller Adapter J 9398-A Pulley Bearing Remover J 9481-A Pulley Bearing and Pulley Installer J 24092 Pulley Hub Adapter Set 1. Clutch plate and hub assembly (2). Page 8418 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 4868 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 8629 PARTS INFORMATION: Pads are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Op. C-0152-RH C-0153-LH Use applicable labor time guide for labor hours. Page 272 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature (ECT) Sensor Engine Coolant Temperature (ECT) W Engine Wiring, RH Side Page 5446 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 298 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 1323 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 518 3. Using the template provided, check the float arm angle (Figures 2 and 3). If the angle does not match the template, grasp the fuel sender with pliers and bend the float arm until it matches the template (angle equals 87 degrees). DAMAGE TO THE GAUGE READOUT WILL OCCUR IF THE SENDER IS NOT HELD PROPERLY DURING THE BENDING PROCEDURE. 4. Install the fuel sender assembly as outlined in the "FUEL PUMP Install" section in the 1992 Light Duty Truck Service Manual. Important: THE FUEL SENDER SEAL RING MUST BE REPLACED (P/N 3893116). 5. Install the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Truck Service Manual. Important: TIGHTEN THE UPPER TANK STRAPS LAST, TORQUE TO 5.5-8.0 N-m 4.0-6.0 lbs.ft. SERVICE PARTS INFORMATION Part Number Description Qty. 3893116 Fuel Sender Seal Ring 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L1225 Page 3474 Throttle Position Sensor: Adjustments N/A: TPS is not adjustable on this engine. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Tires - Slipping on Rim Tires: Customer Interest Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. A/T - Early Converter Clutch Engagement PROM - Programmable Read Only Memory: All Technical Service Bulletins A/T - Early Converter Clutch Engagement Number: 92-75-7A Section: 7A Date: JAN. 1992 Corporate Bulletin No.: 137107 ASE No.: A2 Subject: EARLY TRANSMISSION CONVERTER CLUTCH APPLY Model and Year: 1992 S/T TRUCKS WITH 4.3L ENGINE AND 4L60 AUTOMATIC TRANSMISSION Condition: Some owners of 1992 S/T trucks with 4.3L (LB4) engines and automatic transmissions may comment on early transmission converter clutch (TCC) engagement, TCC engagement just after the 2-3 upshift, or lack of power. Cause: The torque converter clutch is applied at low speeds during some driving conditions. Correction: To correct this condition install a new calibration PROM which raises the TCC apply speed. This calibration will increase the TCC apply speed on a 1992 vehicle to be similar to a 1991 vehicle. (See below) Part PROM Scanner Number Application Broadcast I.D. 16175285 Federal BARL 5551 16175286 California BARM 5561 Parts are expected to be available on January 27, 1992. In case of limited inventory, parts will be placed on 400 Control to waive VIP surcharges. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation at dealer's expense and all other order types will be placed on backorder until the 400 control is removed. Labor Operation Number: T0500 Labor Time: 0.8 Hour Page 1040 Oil Filter: Technical Service Bulletins Engine - Cold Knock Number: 93-155A-6A Section: 6A Date: AUGUST 1993 Corporate Bulletin No.: 376105R ASE No.: A1, A8 Subject: COLD ENGINE KNOCK Model and Year: 1991-93 C/K, R/V, M/L, S/T, G TRUCKS WITH 4.3L, 5.7L AND 7.4L ENGINES THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 93-155-6A DATED MARCH 1993. THE CORRECTION SECTION HAS BEEN CHANGED COMPLETELY. COPIES OF 93-155-6A SHOULD BE DISCARDED. CONDITION: Some late model LB4 (VIN Z 4.3L V6), L05 (VIN K 5.7L V8), and L19 (VIN N 7.4L V8) truck engines have been reported to exhibit "cold knock" on start up. "Cold knock" usually occurs after the vehicle has been completely warmed, then parked for 8 or more hours in ambient temperatures of 35 degrees Fahrenheit or less. "Cold knock" can be separated into three distinct categories. A. Short Duration - Harsh deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. B. Valve Train - Light clatter, tick or click that may last up to 1 minute. C. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. CORRECTION - CATEGORY A: Short Duration Knock For 1992 LB4 4.3L VIN Z ONLY: Install PF52 oil filter. Install a revised PROM that reduces the engine spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROM will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROMs contain the previously released calibration update for torque converter clutch (TCC) lock-up (see Dealer Service Bulletin No. 92-75-7A) if the vehicle has an automatic transmission or neutral gear rattle if the vehicle has a manual transmission (see Dealer Service Bulletin No. 92-187A-7B). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Dealer Service Bulletin No. 92-285B-6E for more information on detonation. NOTE: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. SPO will be temporarily stocking four (4) PROMs for each light duty 1992 model year LB4 application. Base Detonation Fix Cold Knock Fix Combination Cold Knock and Detonation Fix The detonation fix (detonation fix only) PROMs will not be restocked by SPO when the current supply is exhausted. If a detonation fix PROM is required after the existing stock is exhausted, the combination cold knock and detonation PROM is to be used. Special Parts Assistance Center will have information available on each PROM. Select the PROM from the table. Old broadcast code (OLDB/C Code) information has been supplied to help determine if a detonation fix PROM has been installed previously. If the Old B/C Code can be found in the first table, a detonation fix has not been installed. If the broadcast code cannot be found in the tables, call the appropriate marketing division technical assistance group. PROMs are expected to be available from GMSPO August 30, 1993. Component Locations Power Window Switch: Component Locations Rear Window Release Solenoid In Center Of Endgate 2 Door Rear Window Release Components. Below Cigar Lighter Applicable to: 2Door Blazer & Jimmy 4 Door Page 2866 Oxygen Sensor: Technical Service Bulletins Engine Controls - Heated Oxygen Sensor Diagnosis Group Ref.: Engine Fuel & Emission Bulletin No.: 366501 Date: November, 1993 INFORMATION SUBJECT: HEATED OXYGEN SENSOR DIAGNOSIS MODELS: 1992-93 CHEVROLET & GMC LIGHT DUTY TRUCKS WITH 4.3L (LB4/L35), 5.0L (L03) AND 5.7L (L05) ENGINES 1992-93 OLDSMOBILE BRAVADA Some heated oxygen sensors are being replaced in error due to low reference voltage. REFERENCING SERVICE MANUAL Before diagnosing any heated oxygen sensor, be sure to follow the appropriate service manual diagnostics. The fault tree selected is dependent upon which control module system is on the vehicle. DIAGNOSTIC INFORMATION The electronic control module (ECM) normally applies a reference voltage of approximately 450mv to the oxygen sensor. When the ignition is turned "on", the heating element inside the oxygen sensor will immediately start heating the sensor element. The oxygen sensor will become fully functional in 15 to 90 seconds. Because the engine is not running, the gases around the oxygen sensor in the exhaust stream will be mostly ambient air. The high amount of oxygen in the exhaust stream will be interpreted as a lean exhaust and the 450mv reference voltage from the ECM will be pulled low. The oxygen sensor voltage should drop from 450mv to less than 100mv within 90 seconds. Therefore, the oxygen sensor is performing normally. LOW REFERENCE VOLTAGE (This test must be completed within 10 seconds after key up.) If your Tech 1 initial reference voltage is low (less than 300mv), you may have a shorted oxygen sensor. Turn the ignition "off"; allow the sensor to cool for ten minutes and retest. If the voltage is still low, disconnect the oxygen sensor and see if your Tech I now indicates approximately 450mv reference voltage. If so, change the oxygen sensor. HIGH REFERENCE VOLTAGE If your Tech 1 initial reference voltage is high (greater than 600mv), you may have a sensor signal that is shorted to heater voltage. This may cause a code 45. Allow sensor to cool ten minutes and retest. If voltage still remains high, disconnect oxygen sensor. If reference voltage still remains high, you may have a short to voltage in the engine harness or an ECM problem. If you disconnect the oxygen sensor and reference voltage returns to approximately 450mv, replace the internally shorted oxygen sensor. Locations Fuel Filler Neck Page 22 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Page 4606 Fig. 8 Four Wheel Anti-lock Brake Wiring Circuit. 1992 4WD S/T Page 6436 Adapter, High Side - 91172093 0-Rings: Compressor - Small (6) - 91172095 Large - 96068915 Receiver/dryer (2) - 96068488 Suction hose - 96068490 Discharge hose - 96068489 Suction hose - 91172091 Discharge hose - 91172085 1985-89 Spectrum and 1990-93 Storm (R) 1. Using the Service Manual, remove the following components in the order given: a. Condenser (Storm) or radiator grille (Spectrum) (to be reinstalled). b. Triple switch (Storm) or dual pressure switch (Spectrum) (to be reinstalled). c. Receiver/dryer. d. Evaporator to compressor (suction) pipe. e. Check valve from high side service valve (discard). f. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High side adapter fitting (see Step 3 of the retrofit procedure for detailed installation instructions). Low Side - Part of suction hose c. Evaporator to compressor (suction) pipe, and new 0-rings. d. Receiver/dryer and 0-rings. e. Triple switch or dual switch, and new 0-ring. f. Condenser or radiator grille. R-134a amount: 91 - 500 grams (1.10 lb) 92-93 - 600 grams (1.32 lb) PAG oil amount: 150 cc (4.50 oz) Parts Required: Receiver/dryer: 85-89 - 97104795 90-91 - 97104797 92-93 - 97104798 Adapter, High Side: Page 4861 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 7540 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 3568 Spark Plug Wire Routing 4.3W Description and Operation Fuel Pump Relay: Description and Operation OPERATION When the ignition key is first turned to the "ON" position, the control module will energize the fuel pump relay as long as the engine is cranking or running, and the control module is receiving distributor reference pulses. If there are no reference pulses, the control module will shut "OFF" the fuel pump relay within two seconds. An inoperative fuel pump relay can result in extended crank times, particularily if the engine is cold. The oil pressure switch will turn "ON" the fuel pump, as soon as oil pressure reaches about 28 kPa (4 psi). Page 8137 Brake Lamp: Testing and Inspection Troubleshooting Hints 1. The rear lamp systems (taillamps and license plate lamps) all receive voltage from same wire circuit BRN (9) and share same ground G451. If only one system is not working, locate and repair an open in wiring and/or bulbs that pertain to that system. 2. Check condition of STOP-HAZ/TAIL LPS Fuse. If fuse is blown, locate and repair source of overload. Replace fuse. CPI - Fuel Leak May Cause Driveability Problems Fuel Supply Line: Customer Interest CPI - Fuel Leak May Cause Driveability Problems Number: 93-99-6C Section: 6C Date: FEB. 1993 Corporate Bulletin No.: 266306 ASE No.: A1, A8 Subject: CENTER PORT FUEL INJECTION (CPI) LINE CLIPS INFORMATION Model and Year: 1992-93 S/T AND M/L TRUCKS WITH 4.3L ENGINE (RPO 135) Improper installation of the fuel line clips which hold the fuel inlet and outlet tubes to the Central Port Fuel Injection (CPI) unit may result in an internal CPI fuel leak. A fuel leak may cause driveability problems or in extreme cases, hydrolock. Proper Removal and Installation of Fuel Line Clips Removal: Using needle nose pliers, firmly grasp the fuel fitting clip as shown in Figure 1 and pull the clip straight back from the fuel meter body. It may be necessary to lift the opposite side of the clip with a screwdriver. Discard the clip. Installation: Always use a new clip and O-rings (P/N 17112702). Using your fingers as shown in Figure 2, slide the clip over the fuel meter body making sure that the clip properly engages the slots in the fuel inlet and outlet tubes and that the clip is properly positioned over the fuel meter body on both the top and bottom sides. The clip will be properly positioned when the flanges on the fuel meter body protrude from the clip and the clip snaps in place. IMPORTANT: Do not install the clip from the bottom-up position, the clip will not properly retain the fuel lines. Install the clip from the top-down position as shown in Figure 2. Secondly, it is important to note that the fuel lines MUST be in the correct inlet/outlet openings (The lines will fit either opening). Lastly, the fuel lines MUST be correctly seated into the TBI body to allow for proper installation of the clips. Parts Information: Part Number - 17112702 Description - Seal Kit Parts are currently available from GMSPO. Page 6818 For vehicles repaired under the terms of this special coverage, submit a claim with the information shown. Customer Reimbursement All customer requests for reimbursement for previous repairs for the special coverage condition will be handled by the Customer Assistance Center, not by dealers. Disclaimer Page 7070 91 Dk. Argent 6270 C9124 45880 45880 34781 22223 GM-22223 94 Blue Red Metallic B/C 9088 B9018 42481 42481 4240 20051 GM-9088 96 Ultra Silver Metallic B/C 8867 B8795 36457 36547 4023 18112 GM-8867 97 Dk. Grey Metallic B/C 9658 B9127 44153 44153 4313 21024 GM-9658 B/C Basecoat/Clearcoat *M/L Van Only 1992 TRUCK INTERIOR COLORS Page 6592 Compact Disc Player (CD): Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 664 Throttle Position Sensor: Description and Operation TP Sensor Throttle Position Sensor (TPS) PURPOSE The Throttle Position Sensor (TPS) is a non-adjustable potentiometer that senses throttle angle and relays the information to the control module. This input to the control module is used to control the fuel system and most of the control module outputs. CONSTRUCTION The TPS has internally three circuits. One to ground, the other from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage . As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). OPERATION As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation movement to the TP sensor. A potentiometer (variable resistor) within the Throttle Position (TP) sensor assembly changes its resistance in proportion to throttle movement. If the TP sensor senses a Wide Open Throttle (WOT) a voltage signal indicating this condition is sent to the control module. The control module then increases the injector base pulse width, permitting increased fuel flow. LOCATION The non-adjustable Throttle Position (TP) sensor, is mounted on the side of the throttle body opposite the throttle lever assembly. Cooling - Cold Start Fan Noise Fan Clutch: All Technical Service Bulletins Cooling - Cold Start Fan Noise BULLETIN NUMBER: 92-66-56A SECTION: 6B Engine Cooling NUMBER: 2 CORPORATE REFERENCE NUMBER: 1662O3R DATE: May 1993 SUBJECT: COLD START FAN NOISE (INSTALL REVISED "QUICK DUMP" FAN CLUTCH) MODELS: 1987-92 M-VANS WITH 4.3L ENGINE 1990-92 L-VANS WITH 4.3L ENGINE 1988-92 S/T TRUCKS WITH 4.3L ENGINE THIS BULLETIN CANCELS AND REPLACES GMC TRUCK BULLETIN 92-6B-56. IT IS BEING REVISED TO INCLUDE M/L VANS, AND TO SERVICE PARTS INFORMATION AND RPO DEFINITIONS. ALL COPIES OF 92-6B-56 SHOULD BE DISCARDED. CONDITION Some owners of 1987-92 M-vans, 1990-92 L-vans, and 1988-92 S/T vehicles with a 4.3L engine (RPO LB4, LU2, or L35) and air conditioning (RPO C60) may experience higher than normal fan noise upon cold start up (usually fan noise extended beyond 90 seconds after start up). CAUSE This condition may be due to an extended engagement of the fan clutch. CORRECTION The condition may be corrected by installing a revised fan clutch which reduces the fan clutch engagement cycle. Vehicles built after the following VIN breakpoints have the new fan clutch installed in production: Plant VIN Moraine N2514836 Shreveport N8512403 Pontiac West N0508347 Baltimore NB534465 SERVICE PROCEDURE Refer to section 6B1 "FAN CLUTCH REPLACEMENT" in the appropriate Service Manual for removal and installation of the fan clutch. Electrical Specifications Throttle Position Sensor: Electrical Specifications The throttle position sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Page 5371 Symbol Identification Recall 96V195000: Steering Shaft Loosening Steering Shaft: All Technical Service Bulletins Recall 96V195000: Steering Shaft Loosening The intermediate steering shaft loosens at the steering shaft to steering gear coupling. With this looseness, the yoke pinch bolt can wear on the splines of the shaft until there is no longer an interference between the splines and the bolt. This condition can cause body to chassis movement allowing the steering shaft to separate from the steering gear which can result in a loss of steering control. Dealers will retorque the upper and lower bolts to correct specifications. Vehicle Description: Postal vehicles only. Owner Notification: Owner notification is expected to begin during late October 1996. NOTE: Owners who take their vehicles to an authorized dealer on an agreed upon service date and do not receive the free remedy within a reasonable time should contact Chevrolet at 1-800-222-1020. Also contact the National Highway Traffic Safety Administrations Auto Safety Hotline at 1-800-424-9393. 1987 CHEVROLET TRUCK S10 1988 CHEVROLET TRUCK S10 1989 CHEVROLET TRUCK S10 1990 CHEVROLET TRUCK S10 1991 CHEVROLET TRUCK S10 1992 CHEVROLET TRUCK S10 1993 CHEVROLET TRUCK S10 1994 CHEVROLET TRUCK S10 1995 CHEVROLET TRUCK S10 Steering - System Bleed Procedures Power Steering Pump: Technical Service Bulletins Steering - System Bleed Procedures Group Ref.: Steering/Suspension Bulletin No.: 383001 Date: December, 1993 INFORMATION SUBJECT: ILLUSTRATED STEERING SYSTEM BLEED PROCEDURE MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS THIS BULLETIN IS BEING REVISED TO ADD THE 1994 MODEL YEAR AND CHANGE THE ARTWORK. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: BUICK 93-3-5 3/02/93 CADILLAC T-93-76 5/12/93 CHEVROLET 93-146-3B 3/29/93 GM OF CANADA 93-3-102 5/05/93 OLDSMOBILE 2-93-59 (S.G.) 5/14/93 The steering system in 1994 and prior model year cars and light duty trucks should be bled after any of the following: - A power steering component is replaced. - A fluid line is disconnected. - A customer comments on steering system noise. Bleeding air from the steering system should be done in order to prevent pump damage, ensure proper operation, and to eliminate steering system noise. Page 5073 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 4587 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 8220 Fig. 14 Seal Splice Sequence Step 4: Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Using a crimp tool, Fig. 13, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. The sleeve has a stop in the middle of the barrel to prevent the wire from going further, Fig. 14. Close the hand crimper handles slightly to hold the splice sleeve firmly in the proper nest. Step 5: Insert Wires into Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimper tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure is applied to the splice sleeve. Repeat steps 4 and 5 for opposite end of the splice. Step 6: Shrink the Insulation around the Splice Using the Ultratorch J 38125-5 (follow instructions that accompany Ultratorch), apply heat where the barrel is crimped. Gradually move the heat barrel to the open end of the tubing, shrinking the tubing completely as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking is achieved, Fig. 14. Splicing Twisted/Shielded Cable Fig. 15 Twisted/Shielded Cable Twisted/shielded cable is sometimes used to protect wiring from electrical noise (stray signals). For example, two-conductor cable of this construction is used between the ECM and the distributor. See Fig. 15 for a breakdown of twisted/shielded cable construction. Step 1: Remove Outer Jacket Remove the outer jacket and discard it. Be careful to avoid cutting into the drain wire or the mylar tape. Step 2: Unwrap the Tape Unwrap the aluminum/mylar tape, but do not remove it. The tape will be used to rewrap the twisted conductors after the splices have been made. Step 3: Prepare the Splice Page 500 Turn And Hazard Lamp Flashers Page 4213 Disclaimer Master Cylinder Installation Brake Master Cylinder: Service and Repair Master Cylinder Installation Master Cylinder 1. Bench bleed master cylinder. 2. Install master cylinder, combination valve bracket and mounting bolts. 3. Connect brake lines to master cylinder. 4. Connect all wire connectors to master cylinder (if equipped). 5. On models with manual brakes, connect master cylinder push rod to brake pedal. 6. On all models, Bleed brakes. For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Page 8527 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 1307 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Locations Timing Mark Steering - Column Popping Noise Steering Column Bearing: All Technical Service Bulletins Steering - Column Popping Noise Group Ref.: Steering/Suspension Bulletin No.: 333210A Date: December, 1993 SUBJECT: STEERING COLUMN POPPING NOISE (REPLACE UPPER BEARING INNER RACE SEAT) MODELS: 1992-93 PASSENGER CARS EXCEPT CHEVROLET CAVALIER, GEO AND PONTIAC LEMANS 1992-93 LIGHT DUTY TRUCKS EXCEPT GEO TRACKER This bulletin is being re-published to add the labor time for Labor Operation Number E7310. Vehicles affected have TILT steering columns (round style) with the exception of the "W" series (square style). CONDITION: Some owners of vehicles with integral TILT steering columns may hear a pop noise when turning. The noise occurs specifically when the driver is making normal steering turns in either direction and generally when the steering wheel is returning to center. CAUSE: The upper bearing inner race seat under certain conditions may cause a pop noise. The part may have a burr on the inside skirt. CORRECTION: To verify that the upper bearing inner race seat is the cause of the pop noise in the steering column, use the following method: 1. Engage the park brake and start the engine. 2. Point the wheels of the vehicle straight ahead. 3. While listening for a pop noise, rotate the steering wheel in either direction to the wheel stop. Slowly return the wheel back to center. If the noise is not heard, drive the vehicle at a slow speed listening for the noise to occur. Important: When the steering column is warm, the pop noise will be more audible. 4. If a pop noise is heard, replace the upper bearing inner race seat with P/N 7815184. Return the steering wheel back to center with the wheels of the vehicle pointed straight ahead. Turn the ignition lock cylinder to "LOCK" position and then begin the repair. Refer to Section 3F5A/3F5B in the Service Manual to replace the upper bearing inner race seat. Parts are currently available from GMSPO. Labor Operation Number: E7310 Labor Time: 0.6 hrs. For GMC Truck ONLY, use: T7681 Labor Time: 0.4 hrs. (With SIR add .2 hrs.) Page 2610 Throttle Position Sensor: Service and Repair Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 6143 Compressor Clutch: Service and Repair With V5 Compressor Clutch Plate and Hub Assembly Remove or Disconnect Removing Shaft Nut 1. Clamp the holding mixture J 34992 a vise and attach compressor to holding fixture with thumb screws J 34992-1. 2. Keep the clutch hub and drive plate assembly from turning by using the clutch hub holding tool J 33027-A. Remove the shaft nut using shaft nut socket J 33022. Page 3700 1992 LB4 VIN Z For vehicles with "cold knock" only. For vehicles with "cold knock" having previously installed detonation field fix PROM - OR For vehicles with "cold knock" and detonation For 1991-93 model year L05 and L19, 1991 and 1993 LB4 engines, two actions have been found to show a high probability of success incuring short duration cold knock (Category A). General Motors suggests performing the following steps. NOTE: These steps are only applicable to short duration cold knock, and will not eliminate a knock occurring under load. Neither will these actions eliminate a knock lasting more than 10 seconds, nor a knock occurring in a hot or warm engine. Step 1: Install a check valve oil filter Original Filter Install PF35 AC PF1218 PF51 AC PF52 Step 2: Change the oil; use a synthetic oil meeting the API Service SG or SG/CE standard. NOTE: This action is only required once; conventional (non-synthetic) API Service SG or SG/CE oil may be reinstalled at the next oil change. If an LB4 (VIN Z 4.3L V6) or an L05 (VIN K 5.7L V8) continues to exhibit short duration cold knock after performing steps one and two and A/T - Harsh 1-2 Upshift, May Require Cold Soak Accumulator: All Technical Service Bulletins A/T - Harsh 1-2 Upshift, May Require Cold Soak Number: 92-318-7A Section: 7A Date: NOV. 1992 Corporate Bulletin No.: 277135R ASE No.: A2 Subject: HARSH 1-2 UPSHIFT Model and Year: 1992 CAPRICE, CAMARO AND CORVETTE 1992 C/K, G, L/M, S/T TRUCKS TRANSMISSION APPLICATIONS: 1992 HYDRA-MATIC 4L60 TRANSMISSION MODELS: 2AAM, 2ACM, 2ADM, 2AKM, 2BAM, 2BBM, 2BCM, 2BHM, 2BRM, 2BWM, 2CAM, 2CBM, 2CCM, 2CFM, 2CHM, 2CJM, 2CPM, 2FTM, 2FUM, 2FZM, 2HBM, 2HDM, 2HLM, 2KHM, 2KJM, 2KMM, 2LHM, 2MDM, 2MJM, 2MSM, 2SHM, 2TAM, 2TBM, 2TLM, 2TWM, 2WAM, 2WBM, 2WCM, 2YAM, 2YCM SUBJECT: Harsh 1-2 Upshift; Install Service Package VEHICLE APPLICATIONS: B, F, Y Cars C/K, S/T Trucks G, L, M Vans CONDITION (Figure 1): Some vehicles equipped with a 1992 HYDRA-MATIC 4L60 transmission built between Julian Date 061 (March 1, 1992) and Julian Date 171 (June 19, 1992) may experience a harsh 1-2 upshift. NOTE: Once the transmission is brought to operating temperature, the condition may not be able to be reproduced until a "cold soak" (overnight) is performed. CAUSE: The above condition may be caused due to a tapered 1-2 accumulator sleeve. The tapered bore may cause the 1-2 accumulator valve to stick in the bottom of the bore. Locations CMFI Assembly Parts Identification Page 7563 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Locations CMFI Assembly Parts Identification Page 4649 Caliper Knuckle Clearances 5. Measure the clearance between the caliper and the steering knuckle. The clearance at each end of the caliper should be measured individually and added together. this total should be between 0.26-0.60 mm (0.010-0.024 inch). 6. If brake hose was removed, reconnect it and bleed the brakes. 7. Install wheels and tires, lower vehicle and add brake fluid to master cylinder to bring level to 1/4 inch from top. WARNING: Before moving vehicle, pump brake pedal several times to be sure it is firm. Do not move vehicle until a firm pedal is obtained. Page 6157 Reassemble the Rotor and Bearing assembly to the front head of the compressor using Rotor & Bearing Installer J 26271-A. With Installer assembled to the Universal Handle 329886, as shown in Figure 23, force will be applied to the inner race of the bearing and the face of the rotor when installing the assembly onto the front head of the compressor. 5. Install rotor and bearing assembly retainer ring, using Snap Ring Pliers J 6083 (Fig. 9). 6. Apply sealer GM 12345382 (Loctite 242 or equivalent to threads of pulley rim mounting screws. Install screws but do not torque the screws. 7. Rotate the pulley rim and rotor to insure that pulley rim is rotating "in-line". If pulley rim is distorted (does not rotate in-line), adjust or replace pulley rim. 8. Tighten pulley rim mounting screws to 11 N.m (100 in.lbs.) torque and lock screw heads in place by bending screw head washer similar to original crimp. 9. Reinstall Clutch Plate and Hub assembly. 6 Pole Clutch 6 POLE CLUTCH Remove or Disconnect 1. Remove the clutch plate and hub assembly as described previously. Page 2940 Intake Air Temperature Sensor: Description and Operation Intake Air Temperature Sensor PURPOSE The Intake Air Temperature (IAT) sensor is a thermistor and converts the resistance of the sensor to degrees. IAT is used by the control module to adjust fuel delivery and spark timing according to oncoming air density. OPERATION The control module applies a voltage (4-6 volts) signal to the IAT sensor through a resistor within the PCM and measures the voltage. By measuring the voltage, the PCM can determine IAT. Low intake air temperature produces high resistance (100,000 ohms at -40°C/-40°F) and high voltage. High intake air temperature produces a low resistance (70 ohms at 130°C/266°F) and low voltage. Locations Electronic Spark Control (ESC) Module Page 2985 Transmission Position Switch/Sensor: Description and Operation Park/Neutral Switch NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control operation, and transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected. Description and Operation A/C Signal: Description and Operation A/C "ON" Signal NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE: This signal indicates that the A/C control switch is turned "ON" and the pressure switch is closed. The control module uses this signal to adjust the idle speed for improved idle and engine performance. Page 5430 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 5337 Daytime Running Lamps, I/P Wiring Page 7219 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Driveline - Launch Shudder Pinion Flange: All Technical Service Bulletins Driveline - Launch Shudder FILE IN SECTION: 4 - Drive Axle BULLETIN NO.: 56-41-02 DATE: July, 1995 SUBJECT: Driveline Launch Shudder (Install Newly Designed Propeller Shaft) MODELS: 1992-93 Chevrolet and GMC Truck S10803 Models (Pick-up, Regular Cab, and Long Bed) 1992-94 Chevrolet and GMC Truck S10653 Models (Pick-up, Extended cab, and Short bed) 1992-94 Chevrolet and GMC Truck T10653 Models (Pick-up, Extended cab, and Short bed) with 4.3L V-6 Engines (VINs W, Z - RPOs L35, LB4) and Automatic Transmission CONDITION Some owners of pick ups with 4.3L V-6 engines (RPOs L35, LB4), equipped with a two-piece rear propeller shaft and an automatic transmission, may experience a launch shudder condition. This condition may occur from 0-25 mph (0-40 kph) and is more noticeable during hard acceleration when the vehicle is heavily loaded, or when used as a tow vehicle. CAUSE This condition is caused by the driveline angle changes occurring during engine torque and vehicle payload. CORRECTION To repair this condition a newly designed rear propeller shaft and pinion flange is released for service to reduce driveline launch shudder during 0-25 mph (0-40 kph). SERVICE PROCEDURE Remove or Disconnect (Figures 1, 2, and 3) Tool Required: J 8614-01 Companion Flange Holder 1. Place the vehicle on a hoist that will allow free rotation of the rear wheels. 2. Remove both rear tire wheel and drum assemblies. 3. Remove and discard existing two piece rear propeller shaft assembly, retaining the straps and fasteners. 4. Measure the pre-load on the rear axle pinion flange using an inch pound torque wrench, the amount of torque required to turn the pinion (Figure Page 3248 Disclaimer Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Fuel Gauge Sender: All Technical Service Bulletins Instruments - Fuel Tank is Empty, Gauge Reads 1/8 Number: 92-81B-8C Section: 8C Date: MAY 1992 Corporate Bulletin No.: 166305R ASE No.: A6 Subject: FUEL GAUGE READS APPROXIMATELY 1/8 TANK WHEN EMPTY Model and Year: 1990-92 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-81A-8C, DATED APRIL 1992. AN ADDITIONAL PAGE OF ART HAS BEEN ADDED. ALL COPIES OF 92-81A-6F SHOULD BE DISCARDED. Some owners of 1990-92 S/T Utilities may experience inaccurate fuel gauge readings. If this condition is encountered, the fuel gauge will read 1/8 of a tank on the gauge when the tank is empty. This is due to the fuel sender float contacting the bottom of the fuel tank. The condition can be corrected by bending the fuel sender's float arm. The float arm must be bent so that the float arm angle is approximately 87 degrees. Figure 1 demonstrates the fuel sender before and after the bending procedure. When correctly bent, the float arm angle will match the template included in this bulletin. SERVICE PROCEDURE: Important: Before servicing the fuel sender, proper diagnosis of the fuel gauge must be performed according to "DIAGNOSIS OF THE FUEL GAGE" Section 8C-7 in the 1992 Light Duty Truck Service Manual. 1. Remove the fuel tank as outlined in the "FUEL TANK Replacement" section, in the 1992 Light Duty Service Manual. 2. Remove the fuel sender assembly as outlined in the "FUEL PUMP Removal" section, in the 1992 Light Duty Truck Service Manual. Page 1948 New Oil Pressure Sensor Part Numbers for the 1990-93 models Parts are currently available from GMSPO WARRANTY INFORMATION For vehicles repaired under warranty use labor operation N2220. Page 8415 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Page 4184 SERVICE PARTS INFORMATION WARRANTY INFORMATION Page 4752 Caliper Knuckle Clearances 5. Measure the clearance between the caliper and the steering knuckle. The clearance at each end of the caliper should be measured individually and added together. this total should be between 0.26-0.60 mm (0.010-0.024 inch). 6. If brake hose was removed, reconnect it and bleed the brakes. 7. Install wheels and tires, lower vehicle and add brake fluid to master cylinder to bring level to 1/4 inch from top. WARNING: Before moving vehicle, pump brake pedal several times to be sure it is firm. Do not move vehicle until a firm pedal is obtained. Locations Horn Relay Installation Locations Distributor And Coil 4.3W Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Page 2476 Ignition Control Module: Service and Repair Typical Distributor Components REMOVE OR DISCONNECT NOTE It is not necessary to remove ignition distributor assembly from engine. - Distributor cap and rotor. - Connectors from module. - Two module attaching screws. - Lift module from housing and remove. INSTALL OR CONNECT NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. - Module onto housing. - Module attaching screws. Tighten to 2 Nm (18 lb.in.) - Connectors to module. - Rotor and cap. Page 8564 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 2182 Engine Compartment Components Front Of Engine Applicable to: 1992 Blazer, Jimmy, S10 & Sonoma w/4.3L/V6-262 HP Engine STD Engine Page 6406 - Meets GM contamination sensitivity requirements - Self calibrating - Micro-processor controlled - Audio alarm alerts technician Other Refrigerant Identifiers are being advertised which may be available this A/C season. However, ONLY the Kent-Moore J 39851 R12 "Pureguard" meets General Motors' current specifications which ensure recovered refrigerant is compatible with General Motors vehicles and General Motors approved recovery systems. An R134a Pureguard Refrigerant Identifier is currently under development and is anticipated to be available in early 1995. The contamination of R134a refrigerant is not expected to be a concern until the program to retrofit R12 vehicles to R134a becomes more widely used. Future bulletins will be issued to address the recovery and disposal of contaminated refrigerant. Page 8107 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT With A-6 Compressor Compressor Shaft Seal: Service and Repair With A-6 Compressor Remove or Disconnect Tools Required: J 5403 External Snap Ring Pliers J 9392-01 Shaft Seal Remover and Installer J 9553-01 O-Ring Remover J 22974-A Compressor Shaft Oil Seal Protector J 23128-A Compressor Shaft Seal Seat Remover and Installer 1. Clutch plate and hub assembly (2). Page 1466 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Page 1373 Light Duty truck tire rotation recommendations are pictured on the following page. Rotation Guidelines for Tires used on Light Duty Trucks: Tires used on Pickups, Vans and Utility vehicles should be rotated at the first 6,000 miles for Schedule 1 or 7,500 miles for Schedule 2 and then every 15,000 miles thereafter. NOTE: Earlier rotation may be required should irregular wear pafterns develop due to harsh service use - the following rotation patterns are recommended for the various vehicle types and tire combinations. Page 4328 Coat components with specified lubricant during assembly. If components are reused, they should be installed in original position. 1. Press rear bearing onto pinion using suitable spacers. 2. Install front and rear bearing races in housing, using suitable drivers to ensure that races are properly seated. 3. Install straddle bearing in axle housing using straddle bearing installer tool No. J-23322 or equivalent to ensure that bearing is properly seated. 4. Insert pinion through housing, install new collapsible spacer and front bearing over pinion shaft, support pinion and press front bearing onto shaft. 5. Lubricate lips of new seal with grease and install seal using suitable driver to seat seal against shoulder of housing. 6. Install driveshaft companion flange, washer and new pinion nut. 7. Clamp housing in vise, hold flange with suitable tool and torque pinion nut just until all endplay is removed. 8. Check pinion bearing preload (rotating torque) using suitable torque wrench. 9. Continue tightening pinion nut in small increments until specified preload is obtained, checking preload after each adjustment. Exceeding specified preload will collapse spacer too far to be reused. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce bearing preload. A/T - Revised 3-4 Clutch Clutch: All Technical Service Bulletins A/T - Revised 3-4 Clutch Number: 93-143-7A Section: 7A Date: MARCH 1993 Corporate Bulletin No.: 377117 ASE No.: A2 Subject: TRANSMISSION UNIT REPAIR UPDATE 3-4 CLUTCH Model and Year: 1987-93 CAPRICE, CAMARO AND CORVETTE 1987-93 G AND M VAN 1987-93 C/K, R/V AND S/T TRUCKS 1990-93 L VAN WITH 4L60 AND 4L60-E AUTOMATIC TRANSMISSION SERVICE UPDATE BULLETIN COVERS: New Product Information for 1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. This information has been updated since publication of the 1993 Service Manual and should be noted accordingly. Be certain to familiarize yourself with these updates to properly repair the 1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. DATE OF PRODUCTION CHANGE: On January 05, 1993 (Julian Date 005) HYDRA-MATIC 4L60 and 4L60-E transmissions were built with an improved design 3-4 clutch. The improved design consisted of combining the 3rd and 4th clutch ring retainer plate (III. 652), the 3rd and 4th clutch apply (stepped) plate (III. 653) and the 3rd and 4th clutch (steel) plate (III. 654C) into one 3rd and 4th clutch apply plate (III. 653) Figure 1. The 3rd and 4th clutch steel plates are also thicker and the backing plate selection has changed as noted in Figure 2. Locations LH I/P Harness Wiring Page 20 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Page 6387 85-89 - 97104794 90-93 - 97104793 Adapter, Low Side: Part of Hose Asm. 0-rings: Receiver/dryer 85-91 - 94154048 92-93 - 94461700 Switch/pipe - 94461902 Suction hose: 85-86: 1.5L - 97104799; 1.6L - 97104800 90-93: 1.6L - 97104801; 1.8L - 97104803 B. General Information Several items affecting the performance and durability of the system should be considered: 1. Performance When performed properly, the retrofit from R-12 to R-134a will have minimal effect on the system's performance in most climatic conditions found in the United States and Canada. 2. Leakage Experience has shown that most leakage in an A/C system is due to leaks at the joints, or through a small leak in a hose, usually at the coupling. The R-134a molecules are smaller than R-12, and a small leak may result in a faster loss of refrigerant with R-134a. Because of this, it is very important to leak check all vehicles using the J 39400 leak detector, BEFORE the retrofit is performed, and repair any leaks found. "0" rings and hoses used in most GM vehicles are compatible with R-134a and do not need replacement during a retrofit. "0" rings or hoses installed in previous repairs may have been of non-compatible materials if GM parts were not used and will be more likely to deteriorate and leak than the original equipment materials. All "0" rings and hoses available through GMSP0 are compatible with R-134a. Remember that the normal policy is to replace the "0" rings whenever a joint is opened for any reason. 3. Desiccant You may have heard that the currently used desiccant in the accumulator is not compatible with R-134a. Extensive testing has shown that it is, in fact, suitable for use with R-134a, once it has been in service in an R-12 system. The accumulator in these models will not have to be changed during the retrofit procedure, unless the vehicle is more than 5 years old. Vehicles more than 5 years old should have the A/D replaced to add new desiccant for proper system drying. In the event that an accumulator/dryer (A/D) needs to be replaced on a retrofitted system in the future, only A/D's with XH-7 desiccant should be used. The service parts for the 1993 vehicles contain only XH-7 desiccant. The parts for the 1992 and older vehicles may contain either XH-5 or XH-7. Parts containing XH-7 can be identified (see Figure 1) by 1) an "A" printed on the top of the A/D; or 2) if there is a label on top of the A/D, there will be a square with an "A" inside; or 3) if there is a time code and date printed on top of the A/D just under the "Harrison" logo, the A/D contains XH-7. A/D's containing XH-5 can still be used on R-12 vehicles. 4. Improved Cooling Performance There have been service bulletins issued in the past with information improving the cooling performance of existing R-12 systems. These bulletins can also be used to improve the performance of retrofitted vehicles in high ambient temperature climates. 5. PAG or V5 Oil Compatibility Contrary to information published to date outside of General Motors, mineral oil and PAG or V5 oil ARE chemically compatible. The mineral oil left in the system after reclaiming the R-12 can remain in the system with no harmful effects. However, the mineral oil will not mix with the R-134a, and so will not circulate and perform its lubricating function. Testing has shown that most of the mineral oil will eventually collect in the Service and Repair Hydraulic Fluid Accumulator: Service and Repair Fig. 2 Removing Accumulator Do not attempt to repair or apply heat to the accumulator. Before discarding an inoperative accumulator, drill a 1/16 inch diameter hole through the end of the accumulator pan. Do not drill through the piston end. Always wear safety glasses when performing service on the accumulator. 1. Push pedal rod several times to ensure accumulator is depleted. 2. Secure brake booster mounting bracket in a vise with pedal rod facing downward. 3. Place accumulator compressor tool No. J-26889 or equivalent, over master cylinder stud and install retaining nut. 4. Using a C-clamp, depress accumulator can, then insert a punch into hole in housing to unseat retaining ring, Fig. 2. Remove ring from housing using a small screwdriver. If accumulator cannot easily be depressed approximately .10 inch, the accumulator is still charged. This indicates an internal problem with the accumulator valves and the brake booster must be disassembled. 5. Slowly back off C-clamp until tension is relieved, then remove C-clamp, retaining cap and accumulator. 6. Reverse procedure to assemble. Lubricate accumulator can seal with power steering fluid. Ensure accumulator can retaining ring is completely seated in housing groove. Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Page 4195 SERVICE PARTS INFORMATION WARRANTY INFORMATION Page 6644 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 7338 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 5436 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 3084 Catalytic Converter: Description and Operation CAUTION Prolonged operation with a misfiring or flooded engine may cause the converter to overheat. This could cause damage either to the catalyst itself or the operating vehicle and possible personal injury. NOTE When jacking or lifting vehicle from frame side rails, be certain lift pads DO NOT contact catalytic converter or damage to converter may result. Catalytic Converters Page 4569 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. New Windshield/Glass Urethane Adhesive Caulking Kit Windshield: All Technical Service Bulletins New Windshield/Glass Urethane Adhesive Caulking Kit File In Section: 10 - Body Bulletin No.: 83-15-16 Date: October, 1998 INFORMATION Subject: New Windshield and Stationary Glass Urethane Adhesive Caulking Kit Models: 1990-99 All Passenger Cars and Trucks As a result of a change from standard viscosity urethane to high-viscosity urethane, a new Urethane Adhesive Caulking Kit, P/N 12346392, is now available from GMSPO. This kit contains the "High Viscosity" Urethane Adhesive for thicker and more consistent bead size applications. When applied properly, this new high viscosity urethane in many instances will eliminate the need for depth setting blocks or the damming material to control squeeze out. The following is the contents of the new kit: Like the standard viscosity urethane contained in kit (P/N 12346284) that it replaces, it is a one-part, moisture cure product with curing times that vary as a result of changes in either temperature or humidity. THE REQUIRED TIME FOR THIS NEW ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer, IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. Alternate equivalent materials for this kit may be available from a local glass repair shop under the following product numbers: Other manufacturers of Urethane Adhesive that have documented their ability to meet or exceed General Motors specification # 3651M (Performance Requirements for Stationary Glass Bonding Adhesive System Service) are also considered to be equivalent to GM Kit (P/N 12346392). In previously published Corporate Bulletin Number 73-10-54, increasing customer demands for faster service have resulted in quicker two-part urethane adhesives to be made available. Essex Beta Seal U216* (two-part urethane adhesive) also meets the General Motors 3651M Specification and can be Diagram Information and Instructions Underhood Lamp: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 2891 Engine Control Module: Description and Operation Powertrain Control Module (PCM) PURPOSE The Control Module is the control center of the fuel injection system. It constantly looks at the information from various sensors (inputs) and controls the systems (outputs) that affect vehicle performance. The control module also performs the diagnostic control moduletion of the system. It can recognize operational problems, alert the driver through the Malfunction Indicator Lamp (MIL) "Service Engine Soon" light on the instrument panel and store a Diagnostic Trouble Code(s) (DTC) in the control module memory. The DTC identifies the problem areas to aid the technician in performing repairs. OPERATION The control module is an electronic computer designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The control module can control these devices through the use of Quad Driver Modules (QDM). When the control module is commanding a device or a component "ON," the voltage potential of the output is "LOW" or near zero volts. When the control module is commanding a device or component "OFF," the voltage potential of the circuit will be "HIGH," or near 12 volts. The primary function of the QDM is to supply the ground for the component being controlled. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The control module has two parts for service: - Controller which is the control module without the PROM (MEM-CAL). - PROM (Programmable Read Only Memory) which is a separate memory calibrator unit Learning Ability The control module has a "learning" ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected, to clear diagnostic trouble codes or for other repairs. the "learning" process resets and begins again. A change may be noted in the vehicle's performance. To "teach" the vehicle, ensure the engine is at operating temperature. The vehicle should be driven at part throttle, with moderate acceleration and idle conditions until normal performance returns. NOTE The control module must be maintained at a temperature below 85°C (185°F) at all times. This is most essential if the vehicle is put through a baking process. The control module will become inoperative if it's temperature exceeds 85°C (185°F). It is recommended that temporary insulation be placed around the control module during the time the vehicle is in a paint oven or other high temperature processes. Page 7551 Symbol Identification Page 717 Throttle Position Sensor: Adjustments N/A: TPS is not adjustable on this engine. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Page 2129 Distributor: Description and Operation Distributor Reference Signal PURPOSE The distributor reference signal provides the control module with both engine RPM and crankshaft position information. This enables the control module to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the control module receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the control module will not operate the injector. Page 1417 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 5024 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 4624 5. Attach the valve pressure bleeding tools J39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (figure 3) and to the combination valve (figure 4). Tighten tool J39177 only finger tight. 6. Open the pressure bleeder tank valve. 7. Bleed each wheel in the following sequence: - Right rear - Left rear - Right front - Left front NOTE: Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. NOTE: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 8. Open the bleeder valve at least 3/4 of a turn and allow the fluid to flow until no air is seen in the fluid. Tighten the bleeder valve. 9. Repeat step 7 and 8 at each wheel cylinder/caliper until all the air is purged. 10. Disconnect the bleeder tank hose from the bleeder adaptor and remove the bleeder adaptor. 11. Fill the master cylinder to the proper level and replace lid. 12. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs.in.). 13. Remove the valve pressure bleeding tools J39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 14. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. IMPORTANT: DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 15. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. IMPORTANT: DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 16. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs.in.). 17. Remove the bleeder adaptor, if using the pressure bleed procedure (figure 1), and fill the master cylinder to the proper level with brake fluid. 18. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. IMPORTANT: MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 19. Repeat the entire brake bleed procedure if necessary. Manual Bleed Procedure When a pressure bleeder is not available, use the (two person) manual bleed procedure. One person will push on the brake pedal while the other person will open and close the bleed valves. IMPORTANT: You can expect to use two quarts of brake fluid to thoroughly bleed the system. Page 8557 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 3522 Intake Manifold Tuning Valve Circuit Circuit Description: The tuning valve is activated through a relay, by the ECM, during periods of acceleration where engine rpm is over 3000 and throttle position is over 34%. The tuning valve relay is powered by CKT 439 and turned "ON" and "OFF" when the ECM grounds CKT 1387. When the relay is activated, it applies voltage from CKT 39 to CKT 1015, thus, opening the tuning valve. Test Description: Number(s) below refer to circled number(s) on the diagnostic chart. 1. This step determines if the system is functioning at the present time. 2. By cycling the tuning ON" and "OFF" will determine if the tuning valve relay is operating. 3. This will determine if the tuning valve relay has ignition voltage on CKT 39. 4. This will determine if the tuning valve relay has ignition voltage on CKT 439. 5. This step will determine if the relay related wiring to valve or the tuning valve is at fault. 6. This step will determine if the ECM, tuning valve relay or related wiring is at fault. Diagnostic Aids: TPS - An intermittent TPS output will cause the ECM to receive a false input. Page 8530 3. Using an equivalent male terminal from the Terminal Repair Kit, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a DVM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Intermittents and Poor Connections DESCRIPTI0N Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure. ^ The Connector Test Adapter Kit (GM J 35616-A or equivalent) must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to Checking Terminal Contact for specifics. ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined under the Connector and Wire Repair. Troubleshooting Tests PROBING After probing, when reconnecting connectors or replacing terminals, always be sure to reinstall Connector Position Assurance (CPA) and Terminal Position Assurance (TPA). Frontprobe When frontprobing of connectors is required, always use a mating terminal adapter (GM Connector Test Adapter Kit J 35616 or equivalent). The use of proper adaptors will ensure that proper terminal contact integrity is maintained. Backprobe Only backprobe connector terminals when specifically called for in diagnostic procedures. Since backprobing can be a source of damage to connector terminals, extra care must be taken to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large a test probe. After backprobing any connector, always check for terminal damage. If terminal damage is suspected, check for proper terminal contact, see CHECKING TERMINAL CONTACT. Page 3867 Page 3426 Rear Lamp Side Member Wiring Page 1010 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Diagram Information and Instructions Vehicle Speed Sensor/Transducer - Cruise Control: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Page 5256 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 7801 Fuel Gage Is Inaccurate Oil Pressure Gage Indicates High Pressure At All Times Oil Pressure Gage Indicates Low Pressure When Oil Pressure Is Good Oil Pressure Gage Is Inaccurate Temperature Gage Is Inaccurate Page 6263 7. Clutch spacer shims (3). 8. Use the originals if possible to give the same gap. 9. New felt ring. - If the clutch was not disassembled, reinstall the clutch front plate. Page 1721 Harmonic Balancer - Crankshaft Pulley: Specifications Torsional Damper Bolt 70 ft.lb Page 5069 Figure 7 Figure 8 Figure 9 Figure 10 Notes, Warnings, and Hints Brake Master Cylinder: Fundamentals and Basics Notes, Warnings, and Hints REMOVAL WARNING: DOT 3 or DOT 4 brake fluid is very corrosive to your vehicles finish. Removing master cylinders can be a messy process. To prevent or minimize any possible damage perform the following: Siphon all brake fluid from the master-cylinder reservoir prior to removal. - Use a fender cover to protect the vehicles finish. - Use a drip pan to catch all fluid that leaks from the master-cylinder during removal. - Any brake fluid which contacts the vehicles finish should be washed off immediately. - Any brake fluid which drips onto electrical connections should be immediately removed (aerosol brake cleaner works well for this). After the brake lines have been disconnected from the master-cylinder place vacuum caps over ends of the lines to prevent further leakage or contamination. Once the master-cylinder has been removed place it in a drip pan. Although the reservoir is empty, brake fluid trapped within the cylinder bore will continue to slowly leak out. OVERHAUL WARNING: Never hone aluminum cylinders, if deposits cannot be removed with crocus cloth the cylinder should be replaced. Check the cylinder bore for excessive clearance. With the piston installed you should not be able to install a 0.006 inch feeler gauge between piston and cylinder. If the clearance is greater than 0.006 inches the cylinder should be replaced. When installing the piston and seals into the cylinder always use clean brake fluid or assembly lubricant to lubricate the components. INSTALLATION Prior to installation the master-cylinder should be bench bled (this can be done on the vehicle but it is much easier on a workbench. NOTE: Normal brake bleeding procedures will not remove air which is trapped in the cylinder bore area of a master-cylinder. Attach the brake line fittings prior to snugging down the master-cylinder retaining bolts. The fittings are much easier to start turning when the master-cylinder is still loose. WARNING: Remember to tighten the retaining bolts after the brake lines are installed and tightened. When snugging down the retaining bolts, alternately tighten them in small increments. This prevents the master-cylinder or push rod from becoming cocked. Upon installing the master-cylinder the entire brake system (front and rear) will need to be bled. Air enters the brake system as soon as the brake lines are removed. It only requires a very small amount of air in the system to create a soft brake pedal. WARNING: Never test drive a vehicle after a master-cylinder replacement until a firm brake pedal with a 75% reserve is established. Page 305 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Locations EGR Valve Position Sensor: Locations Engine Wiring, LH Side Page 1801 For vehicles repaired under warranty, use: Page 7465 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 3434 Idle Speed/Throttle Actuator - Electronic: Testing and Inspection Idle Air Control (IAC) System Check Page 5373 Symbol Identification Wire Color Code Identification Black: BLK Blue: BLU Brown: BRN Gray: GR Green: GRN Natural: NAT Page 727 Electronic Spark Control (ESC) Circuit Circuit Description: The Code 43 circuit consists of two knock sensors with one wire that goes directly to the ECM. There are two Code 43 checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 4.4 volts. If voltage is either too high or too low for 2 or more seconds, Code 43 will set. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3800 rpm, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, Code 43 will set. Diagnostic Aids: The ECM applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the ECM, is able to read this signal as knock and incrementally retard spark. If the ESC system checks OK, but detonation is the complaint, See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Page 5410 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Locations Engine Wiring, LH Side Page 1670 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Lighting - Exterior Lamp Condensation and Replacement Tail Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Page 5901 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Body - Stain/Film On Windshield Glass Perimeter Windshield: Customer Interest Body - Stain/Film On Windshield Glass Perimeter TECHNICAL Bulletin No.: 09-08-48-006 Date: September 18, 2009 Subject: Clear Stain or Film on Inside Perimeter of Windshield Glass (Clean/Polish Glass) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Condition Some customers may comment on a clear stain or film on the inside of the windshield glass. This condition appears along the outer edges of the glass along the top, bottom or A-pillar areas. Normal glass cleaning procedures will not remove the stain. Cause The assembly plant uses a clear sealer/primer on the outer edge of the windshield glass to improve adhesion to the urethane adhesive that bonds the windshield glass to the vehicle body. Excess sealer/primer may drip or flow onto the windshield and cause a stain. Once the sealer/primer dries, it may appear to have etched the glass. Correction Note A "white" type of toothpaste is recommended for this repair. Gel-type toothpaste may provide less satisfactory results. Use a small amount of toothpaste on a soft, cotton cloth to polish the stained area. It may be necessary to wrap the cloth around a paint stir stick or a similar tool to reach the lower corners of the windshield glass. After polishing the glass, clean the inside of the windshield glass with a clean, damp, cotton cloth and verify all of the stain is removed. Do not use any cleaners or solvents - use only clean warm water. Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use: Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Page 7777 Fig. 25 Radio Receiver Removal & Installation Fig. 26 Speaker Removal & Installation 1. Disconnect battery ground cable. 2. Remove lamp switch trim plate attaching screws, then pull lamp switch rearward and disconnect wiring harness, Fig. 23. 3. Remove A/C and heater control assembly attaching screws, then pull control assembly rearward and disconnect electrical connector. 4. Remove filler panel attaching screws and filler panel, Fig. 24. 5. Remove instrument cluster housing attaching nuts and cluster housing. 6. Remove instrument cluster attaching nuts, then pull cluster rearward and disconnect electrical connector and speedometer cable. 7. Disconnect transmission control cable from steering column, then remove steering column attaching bolts and lower steering column. Page 4971 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7373 are using. Step 6: Tape the Splice Fig. 11 Proper First Taping Fig. 12 Proper Second Taping Center and roll the splicing tape. The tape should cover the entire splice. Roll on enough tape to duplicate the thickness of the insulation on the existing wires. Do not flag the tape. Flagged tape may not provide enough insulation, and the nagged ends will tangle with the other wires in the harness, Fig. 11. If the wire does not belong in a conduit or other harness covering, tape the wire again. Use a winding motion to cover the first piece of tape, Fig. 12. Splicing Copper Wire Using Crimp and Seal Splice Sleeves DESCRIPTION Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one to one splice. They are to be used where there are special requirements such as moisture scaling. (Crimp and Seal splice sleeves are included in the GM J 38125-A Terminal Repair Kit.) Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The Crimp and Seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one to one splice. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1.5 in.) away from other splices, harness branches or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. Locations Backup Lamp Switch: Locations Rear Engine Components. LH Side Of Transmission Applicable to: 1991-92 4.3L/V6-262 Engine, Except Bravada & Automatic Transmission Page 3806 CORRECTION (Figure 2): To improve the 1-2 shift, install the service package listed in this bulletin. A 1-2 accumulator valve and 1-2 accumulator valve sleeve (which, normally, is not serviceable) is included in the package. SERVICE PARTS INFORMATION: Package Number Transmission Models 8687992 2AAM, 2ACM, 2BAM, 2BBM, 2BCM, 2BHM, 2BRM, 2BWM, 2CAM, 2CBM, 2CCM, 2CFM, 2CHM, 2CJM, 2FTM, 2FUM, 2HBM, 2HLM, 2KHM, 2KJM, 2KMM, 2LHM, 2MJM, 2SHM, 2TLM, 2TWM, 2WAM, 2WBM, 2WCM 8688900 2ADM, 2AKM, 2CPM, 2FZM, 2HDM, 2MDM, 2MSM, 2TAM, 2TBM, 2YAM, 2YCM WARRANTY INFORMATION: Labor Operation Number: T7601 (Valve Body, R&R;). Labor Time: C/K, G, L/M, S/T Trucks 1.8 hrs. Labor Time: Caprice 1.7 hrs. Camaro 1.4 hrs. Corvette 1.3 hrs. Corvette with folding top add 0.6 hrs. SERVICE MANUAL REFERENCE: Refer to the HYDRA-MATIC 4L60 Unit Repair Section of the appropriate service manual for repair information. Page 5023 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 374 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 750 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 3647 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Locations RH I/P Harness Wiring Lighting - Exterior Lamp Condensation and Replacement Brake Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Page 1601 Camshaft: Specifications Camshaft Sprocket Bolts 21 ft.lb Camshaft Thrust Plate Screws 8.75 ft.lb Page 7135 Disclaimer A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 6154 2. Remove Rotor and Bearing assembly retaining ring, using Snap Ring Pliers J 6083 (Fig. 9). Mark the location of the clutch coil terminals. If only the Clutch Rotor and/or Rotor Bearing are to be replaced, bend the screw head washer away from the pulley rim and remove the six (6) mounting screws before proceeding with Step 3. Discard the mounting screws. 3. Install Rotor and Bearing Puller J 25031 down into the rotor until the Puller arms engage the recessed edge of the rotor hub. Hold the Puller and arms in place and tighten the Puller screw against the Puller Guide to remove the Clutch Rotor and Bearing assembly (Fig. 10), being careful not to drop the Puller Guide. 4. If the pulley rim mounting screws were removed in Step 2, only the Clutch Rotor and Bearing assembly will be removed for replacement. The Clutch Coil and Housing assembly is pressed onto the Front Head of the compressor with a press fit and will not be removed unless the pulley rim mounting screws are left securely in place and the pulley rim pulls the Coil and Housing assembly off with the total Clutch Rotor and Pulley Rim Assembly. Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Paint - Codes & Cross References Paint: All Technical Service Bulletins Paint - Codes & Cross References GMC NUMBER: 92-10-05 GROUP: 10 Body Section DATE: August, 1991 CORPORATE NUMBER: 161702R SUBJECT: 1992 PAINT CODES, ASSEMBLY PLANT IDENTIFICATION AND PAINT SUPPLIERS MODELS: ALL 1992 TRUCKS 1992 ASSEMBLY PLANT PAINT IDENTIFICATION Attached is a current listing of the various assembly plants and their paint suppliers. It should be noted, however, that paint suppliers are subject to change at any given time. Paint Type Assembly Plant Plant Paint (Trucks) Code Supplier Basecoat/Clear- Baltimore, MD B PPG coat Enamel (M/L) High Solids Janesville, WI J Dupont Enamel (MD) High Solids Lordstown, OH 7 BASF Enamel (G) High Solids Moraine, OH 2 Dupont Enamel (S/T) Basecoat/Clear- Oshawa Truck 1 ICI coat Waterborne Plant (C/K) High Solids Pontiac-West, 0 BASF Enamel MI (S/T) Basecoat/Clear- Pontiac-East, MI E Dupont coat Enamel (C/K) Medium Solids Scarborough, 4 ICI Enamel Ontario (G) High Solids Shreveport, LA 8 BASF Enamel (S/T) Basecoat/Clear- Ft. Wayne, IN Z Dupont coat Enamel (C/K) Basecoat/Clear- Janesville, WI J PPG coat Enamel (C/K-Suburban, Yukon, Sierra Crew Cab) The following is a list of paint code numbers from various suppliers for the 1992 model year. These colors can be obtained locally. BASF refinished paints are available in: A - Alphacryl(R) D - Diamont 88(R) SO - Diamont Solo(R) 21 - Glasurit-21(R) 54 - Glasurit-54(R) S - Limco Select(R) L - Limco Supreme Gold(R) Page 6171 Bearing Staked In Place Noisy bearing operation and reduced bearing life may result if outer bearing race is deformed while staking, The stake metal should not contact the outer race of the bearing. Stake three places 120 degrees apart. Installing Pulley Rotor And Bearing Assembly 5. With the compressor mounted to the J 33026 holding fixture, position the rotor and bearing assembly on the front head. 6. Position the J 33017 pulley, rotor and bearing installer and J 33023-A puller pilot directly over the inner race of the bearing. 7. Position puller crossbar J 8433-1 on the puller pilot J 33023-A and assemble the two J 33026-2 through bolts and washers through the puller bar slots and thread them into the J 33026 holding fixture. The thread of the through bolts should engage the full thickness of the holding fixture. 8. Tighten the center screw in the J 8433-1 puller crossbar to force the pulley rotor and bearing assembly onto the compressor front head. Should the J 33017 pulley rotor and bearing installer slip off direct in-line contact with the inner race of the bearing, loosen the J 8433-1 center forcing screw and realign the installer and pilot so that the J 33017 installer will properly clear the front head. 9. Install rotor and bearing assembly retainer ring, using snap ring pliers J 6083. 10. Reinstall clutch plate and hub assembly. Clutch Coil Remove or Disconnect 1. Perform Steps 1 through 4 of "Clutch Rotor and/or Bearings" removal procedure. Mark clutch coil terminal location on compressor front head. Page 6320 Evaporator Core: Service and Repair EVAPORATOR CORE REPLACEMENT Evaporator Tube Replacement Evaporator And Blower Assembly Component View Locations Turn And Hazard Lamp Flashers MUNCIE 5LM60 (HM-290) 4 & 5 Speed Extension Housing: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Rear Housing Bolts .............................................................................................................................. ................................................................... 17 ft. lbs. Page 304 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 2530 Manifold Pressure/Vacuum Sensor: Locations CMFI Intake Manifold Sensors/Valves Page 3505 Throttle Position Sensor: Service and Repair Throttle Position (TP) Sensor REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 5646 Steering Gear: Description and Operation Nippon Seiko Recirculating Ball Gear Manual Steering Fig. 1 Cross Sectional View Of Nippon Seiko Steering Gear The pitman arm is rigidly connected to the outer end of the sector gear shaft. Between the ball nut and the worm, Fig. 1, is a row of steel balls, which serves two purposes: to provide rolling contact between the ball nut and worm shaft and to keep the ball nut engaged with the worm as if the two were threaded together. With the nut prevented from turning, the rotation of the worm causes the nut to move up or down the shaft. The worm shaft is an extension of the steering shaft. As the steering wheel is turned, the steel balls roll along in the groove and the nut moves up or down. The steel ball that has reached the end of the groove in the nut enters the return guide. The guide sends the ball back to the other end of the same groove and the row of balls recirculates. The nut then turns the sector gear which turns the pitman arm. This steering gear is a precision machined unit, calling for special tools for internal repair. The unit should be replaced instead of being repaired. Page 3125 EGR AND EVRV SOLENOID 4.3 L Page 7837 4L60 & 4L60-E Transmission Transmission Speed Sensor: Specifications 4L60 & 4L60-E Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Page 3868 Locations Fog Lamp Switch And Relay Wiring Page 6083 Heater Wiring - Without A/C Page 6389 Important: All of the following parts are NOT NEEDED for a normal retrofit. Follow the bulletin procedures to determine which parts you need! Individual vehicle kits are not necessary, since most of the parts are generic and only a few parts are needed for most vehicles. GEO Parts are listed in "Platform Details." Parts are currently available from GMSPO. D. Warranty Information 1. Vehicle Still Within the Original New Vehicle Limited Warranty Period When GM models for the years listed in the bulletin require repairs to the refrigerant system and the vehicles are still covered under the New Page 8309 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 8307 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 8523 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 46 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 1292 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 4712 Brake Shoe: Fundamentals and Basics Notes, Warnings, and Hints PRIOR TO REMOVING THE SHOES - Clean the shoes, hardware, and backing-plate thoroughly for the following reasons. Initially the springs will appear black (from brake dust). The springs are actually color coded and it is very important to reinstall the springs in the correct location. - The shoes and hardware will need to be cleaned to determine if an overheating condition has occurred (discolored bluish-purple). - Inhaling brake dust is VERY HAZARDOUS TO YOUR HEALTH. WARNING: Do not use compressed air to clean the brake assembly. - Verify the Leading and Trailing shoes are installed in the correct relationship. - Verify the new brake components exactly match the old ones. DURING REMOVAL - If there is any possibility that the shoes may reused, remove any drip pans that may be under the brake assembly and handle the shoes carefully when removing. NOTE: WORK ON ONE SIDE AT A TIME (unless you are very familiar with the system). The other side may then be used as a model for reassembling. INSTALLATION - Clean and lubricate the backing-plate contact pads with a high temperature silicone lubricant. Page 5314 Disclaimer Page 2305 Flushing Procedures using DEX-COOL(R) Important: The following procedure recommends refilling the system with DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. This coolant is orange in color and has a service interval of 5 years or 240,000 km (150,000 mi). However, when used on vehicles built prior to the introduction of DEX-COOL(R), maintenance intervals will remain the same as specified in the Owner's Manual. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling system flush and fill machine is not available, drain the coolant and dispose of properly following the draining procedures in the appropriate Service Manual. Refill the system using clear, drinkable water and run the vehicle until the thermostat opens. Repeat and run the vehicle three (3) times to totally remove the old coolant or until the drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with DEX‐COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. Then slowly add clear, drinkable water (preferably distilled) to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and reverify the coolant level. If necessary, add clean water to restore the coolant to the appropriate level. Once the system is refilled, reverify the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. The concentration levels should be between 50% and 65%. Flushing Procedures using Conventional Silicated (Green Colored) Coolant Important: 2004-2005 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX‐COOL(R). The Aveo and Wave are filled with conventional, silicated engine coolant that is blue in color. Silicated coolants are typically green in color and are required to be drained, flushed and refilled every 30,000 miles (48,000 km). The Aveo and Wave are to be serviced with conventional, silicated coolant. Use P/N 12378560 (1 gal) (in Canada, use P/N 88862159 (1 L). Refer to the Owner's Manual or Service Information (SI) for further information on OEM coolant. Important: Do not mix the OEM orange colored DEX-COOL(R) coolant with green colored coolant when adding coolant to the system or when servicing the vehicle's cooling system. Mixing the orange and green colored coolants will produce a brown coolant which may be a customer dissatisfier and will not extend the service interval to that of DEX-COOL(R). Conventional silicated coolants offered by GM Service and Parts Operations are green in color. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling systems flush and fill machine is not available, drain coolant and dispose of properly following the draining procedures in appropriate Service Manual. Refill the system using clear, drinkable water and run vehicle until thermostat opens. Repeat and run vehicle three (3) times to totally remove old coolant or until drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with a good quality ethylene glycol base engine coolant, P/N 12378560, 1 gal (in Canada, use P/N 88862159 1 L), conforming to GM specification 1825M, or recycled coolant conforming to GM specification 1825M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% good quality ethylene glycol base (green colored) engine coolant, P/N 12378560 1 gal., (in Canada, use P/N 88862159 1 L) conforming to GM specification 1825M. Then slowly add clear, drinkable water (preferably distilled) to system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and recheck coolant level. If necessary, add clean water to restore coolant to the appropriate level. Once the system is refilled, recheck the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. Concentration levels should be between 50% and 65%. Parts Information Warranty Information Page 7468 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 4886 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 6930 The GM Vehicle Care Odor Eliminator product is an effective odor elimination product when used properly. It must come into direct contact with the odor source. It should be used in conjunction with diagnostic procedures to first eliminate the root cause of the odor. Some procedures for use after odor root cause correction are: STEP TWO: ^ Use the trigger spray head. ^ Put a drop of dish soap the size of a quarter in the bottom of a bottle. ^ Add 8 oz. of GM Vehicle Care Odor Eliminator (1 cup) to the dish soap and top off the bottle with tap water. ^ This formula should be used on hard surfaces (dash, interior plastic molding, and floor pan) STEP THREE: The third step to neutralizing the vehicle is a light to medium treatment of all carpeting and upholstered seats with the GM Vehicle Care Odor Eliminator formula and a wide fan spray setting (at full strength) (i.e.: carpeting on the driver's side requires 4-5 triggers pulls for coverage). The headliner and trunk should be sprayed next. Lightly brushing the formula into the carpeting and upholstery is a recommended step for deep odor problems. The dash and all hard surfaces should be sprayed with dish soap/water mixture. Let stand for 1-2 minutes then wipe off the surface. STEP FOUR: (vehicle ventilation system treatment) The ventilation system is generally the last step in the treatment of the vehicle. a. Spray the GM Vehicle Care Odor Eliminator formula into all dash vents. (1-2 trigger pulls per vent). b. Start the vehicle and turn the vehicle fan on high cool (not A/C setting). c. Spray the formula (10 trigger pulls) into the outside fresh air intake vent (cowl at base of windshield) d. Enter the vehicle after 1 minute and wipe off the excess formula spurting out of the dash vents. e. Smell the air coming from the dash vents. If odors are still present, spray another 5 triggers into the cowl, wait another minute and smell the results. Once you have obtained a fresh, clean smell coming from the vents, turn the system to the A/C re-circulation setting. Roll up the windows, spray 3-5 pumps into the right lower IP area and let the vehicle run with the fan set on high for 5-7 minutes. Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. Additional Suggestions to Increase Customer Satisfaction Here are some additional ideas to benefit your dealership and to generate greater customer enthusiasm for this product. ^ Keep this product on-hand for both the Service Department and the Used Car lot. Add value to your used car trades; treat loaner and demo cars during service and at final sale to eliminate smoke, pet, and other common odors offensive to customers. Make deodorizing a vehicle part of your normal vehicle detailing service. ^ Consider including GM Vehicle Care Odor Eliminator as a give-away item with new vehicle purchases. Many dealers give away as "gifts" various cleaning supplies at time of delivery. GM Odor Eliminator is one of a few products GM offers that has as many uses in the home as in the vehicle. Customers may find this product can be used for a host of recreational activities associated with their new vehicle, such as deodorizing a boat they tow, or a camper. ^ GM Odor Eliminator and many of the GM Vehicle Care products offer you the chance to increase dealership traffic as these superior quality products cannot be purchased in stores. Many Dealerships have product displays at the parts counter. Consider additional displays in the Customer Service Lounge, the Showroom and at the Service Desk or Cashier Window. Many customers who purchase vehicles and receive regular maintenance at your dealership may never visit the parts counter, and subsequently are not exposed to the variety and value that these products offer. Parts Information Page 7354 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Page 8413 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 7192 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Page 1197 Technical Service Bulletin # 431207E Date: 970101 A/C - Retrofitting R-12 to R-134a File In Section: 1 - HVAC Bulletin No.: 43-12-07E Date: January, 1997 INFORMATION Subject: Guidelines for Retrofitting R-12 Vehicles to R-134a Models: 1984-94 Passenger Cars and Trucks (See List Below) This bulletin is being revised with the following changes: 1. Addition of all remaining GM vehicles, as listed. 2. Format rearranged for easier use. Please discard Corporate Bulletin Number 43-12-07D (Section 1 - HVAC). Car/Truck Platform Coverage Starts: 1984 - A, B, D, E, F, J, K, P, Y Carlines 1985 - C, M, N, R, S Carlines 1986 - H Carline 1987 - L, V (Allante) Car lines; M/L, G, R/V, S/T, P Truck lines 1988 - T (LeMans), E (Reatta), W Car lines; C/k, MED. Duty Truck lines 1989 - Tracker 1990 - U Van Vehicles Not Covered: T (Chevette and T1000), G RWD, C RWD, and X Car If a vehicle is not covered in the list above, GM's recommendation is that the vehicle continue to be serviced with R-12. This bulletin outlines the detailed retrofit procedures, as well as providing background information on many components and procedures. It is important to follow the bulletin, since each car and truck line has unique parts and procedures. However, the basic procedure is simple, and will become easier as you complete more retrofits. Page 4154 Clutch Slave Cylinder: Service and Repair Secondary (Slave) Cylinder Fig. 3 Clutch Slave Cylinder REMOVAL 1. Raise and support vehicle. 2. Disconnect hydraulic line from slave cylinder, Fig. 3. 3. Remove slave cylinder retaining nuts, then the slave cylinder. INSTALLATION 1. Connect hydraulic line to slave cylinder, Fig. 3. 2. Bleed system. 3. Position slave cylinder on bellhousing, then install retaining nuts and torque to 10-15 ft. lbs. Page 6929 Carpet: Technical Service Bulletins Interior - Elimination Of Unwanted Odors INFORMATION Bulletin No.: 00-00-89-027E Date: September 29, 2008 Subject: Eliminating Unwanted Odors in Vehicles Models: 2009 and Prior GM Passenger Cars and Trucks (including Saturn) 2009 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and refine the instructions. Please discard Corporate Bulletin Number 00-00-89-027D (Section 00 - General Information). Vehicle Odor Elimination General Motors offers a product that may control or eliminate odors in the interior and luggage compartment areas of GM vehicles. GM Vehicle Care Odor Eliminator is a non-toxic, biodegradable odor remover. This odorless product has been shown to greatly reduce or remove objectionable smells of mold and mildew resulting from vehicle water leaks (as well as customer created odors, i.e. smoke). You may use GM Vehicle Care Odor Eliminator on fabrics, vinyl, leather, carpet and sound deadening materials. It may also be induced into HVAC modules and instrument panel ducts (for the control of non-bacterial related odors). Important: This product leaves no residual scent and should not be sold as or considered an air freshener. Product action may result in the permanent elimination of an odor and may be preferable to customers with allergies who are sensitive to perfumes. How to Use This Product GM Vehicle Care Odor Eliminator may be sprayed on in a ready-to-use formula or used in steam cleaners as an additive with carpet shampoo. This water-based, odorless product is safe for all vehicle interiors. Do not wet or soak any interior surface that plain water would cause to deteriorate, as this product will have the same effect. Also avoid letting this product come into contact with vinegar or any acidic substance. Acid-based products will hamper the effectiveness of, or render GM Vehicle Care Odor Eliminator inert. Note: Complete eight page treatment sheets are enclosed within each case of GM Vehicle Care Odor Eliminator. These treatment instructions range from simple vehicle odor elimination to full step by step procedures for odor removal from water leaks. If lost, contact 800-977-4145 to get a replacement set faxed or e-mailed to your dealership. Instructions and cautions are printed on the bottle, but additional help is available. If you encounter a difficult to eliminate or reoccurring odor, you may call 1-800-955-8591 (in Canada, 1-800-977-4145) to obtain additional information and usage suggestions. Important: This product may effectively remove odors when directly contacting the odor source. It should be used in conjunction with diagnostic procedures (in cases such as a water leak) to first eliminate the root cause of the odor, and then the residual odor to permanently correct the vehicle condition. Vehicle Waterleak Odor Elimination STEP ONE: Confirm that all water leaks have been repaired. Determine what areas of the vehicle were water soaked or wet. Components with visible mold/mildew staining should be replaced. Isolate the odor source inside the vehicle. Often an odor can be isolated to an area or component of the vehicle interior by careful evaluation. Odor evaluation may need to be performed by multiple persons. Another method of isolating an odor source is to remove and segregate interior trim and components. Plastic sheeting or drop cloths can be used to confine seats, headliners, etc. to assist in evaluation and diagnoses. If appropriate the vehicle and interior trim should be evaluated separately to determine if the odor stays with the vehicle or the interior components. Odors that stay with the vehicle may be isolated to insulating and sound deadening materials (i.e. water leak at the windshield or standing water in the front foot well area caused mold/mildew to form on the bulkhead or kick panel sound deadening pads. If the interior is removed the floor pan and primed/painted surfaces should be treated with bleach/soap solution, rinsed with clean water and dried. Interior surfaces should then be treated with GM Vehicle Care Odor Eliminator product before reinstalling carpet or reassembling. Page 2522 Rear Of Engine Description and Operation Overvoltage Protection Relay: Description and Operation PURPOSE Inform the control module that there is a basic generator over voltage problem. OPERATION PCM/ECM If voltage is greater than 19.5 volts for 2 seconds at PCM terminal "E16" (ECM is "C16"), the control module sets Diagnostic Trouble Code 53, the automatic transmission pressure control solenoid is turned "OFF", the automatic transmission shifts immediately to third gear, and TCC operation is inhibited. (the setting of additional DTC's may result.) VCM If voltage is greater than 17.1 volts at VCM terminal "GR2" sets Diagnostic Fault Code P1632. For 2 seconds after the fault is detected, the VCM will disengage its outputs. This may result in additional DTC's being set. Page 7603 Maxifuses in future vehicles. FUSIBLE LINKS Fig. 3 Good and Damaged Fusible Links Fig. 6 Wire Size Conversion Table In addition to circuit breakers and fuses, some circuits use fusible links to protect the wiring. Like fuses, fusible links are "one-time" protection devices that will melt and create an open circuit, Fig. 3. Not all fusible link open circuits can be detected by observation. Always inspect that there is battery voltage past the fusible link to verify continuity. Fusible links are used instead of a fuse in wiring circuits that are not normally fused, such as the ignition circuit. For AWG sizes, each fusible link is four wire gage sizes smaller than the wire it is designed to protect. For example: to protect a 10 gage wire use a 14 gage link or for metric, to protect a 5 sq.mm wire use a 2 sq.mm link, Fig. 6. Links are marked on the insulation with wire gage size because the heavy insulation makes the link appear to be a heavier gage than it actually is. The same wire size fusible link must be used when replacing a blown fusible link. Fusible links are available with three types of insulation: Hypalon(r), Silicone/GXL (SIL/GXL) and Expanded Duty. All future vehicles that use fusible links will utilize the Expanded Duty type of fusible link. When servicing fusible links, all fusible links can be replaced with the Expanded Duty type. SIL/GXI fusible links can be used to replace either SIL/GXI or Hypalon(r) fusible links. Hypalon(r) fusible links can only be used to replace Hypalon(r) fusible links. Determining characteristics of the types of fusible links: Hypalon(r) (limited use): only available in 0.35 sq.mm or smaller and its insulation is one color all the way through. - SIL/GXL (widely used): available in all sizes and has a white inner core under the outer color of insulation. - Expanded Duty: available in all sizes, has an insulation that is one color all the way through and has three dots following the writing on the insulation. Service fusible links are available in many lengths. Choose the shortest length that is suitable. If the fusible link is to be cut from a spool, it should be cut 150-225 mm (approx 6-9 in.) long. NEVER make a fusible link longer than 225 mm (approx 9 in.). Speedometer - Registers When Vehicle is Stationary Vehicle Speed Sensor: All Technical Service Bulletins Speedometer - Registers When Vehicle is Stationary Number: 93-50-8C Section: 8C Date: NOV. 1992 Corporate Bulletin No.: 268305R ASE No.: A6 Subject: SPEEDOMETER REGISTERS WHEN VEHICLE IS STATIONARY Model and Year: 1988-93 C/K AND 1989-93 S/T TRUCKS Some 1988-93 C/K, and 1989-93 S/T vehicles will register a speed, often as high as 12 MPH, when engine speed is increased with the vehicle stationary and the transmission in neutral. This condition is due to the sensitivity of the vehicle speed sensor and is not an indication of a malfunction. When the engine is "reved up" normal engine vibration is transmitted through the transmission, causing the reluctor wheel used for speed sensing to also vibrate. Although the vibration is minute the sensitivity of the speed sensor is such that a speed signal is induced. As previously stated, the vibration is normal and the level of sensitivity of the speed sensor must be maintained to accurately support vehicle systems such as cruise control and antilock brakes that require vehicle speed input. When the vehicle is moving, the spinning reluctor wheel overshadows any vibration that may be present and an accurate speed reading is maintained. Since the condition is normal, no attempt to eliminate it should be made. Replacing parts will not be effective. Page 3593 Electronic Spark Control (ESC) Circuit Circuit Description: The Code 43 circuit consists of two knock sensors with one wire that goes directly to the ECM. There are two Code 43 checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 4.4 volts. If voltage is either too high or too low for 2 or more seconds, Code 43 will set. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3800 rpm, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, Code 43 will set. Diagnostic Aids: The ECM applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the ECM, is able to read this signal as knock and incrementally retard spark. If the ESC system checks OK, but detonation is the complaint, See: Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Page 2239 SERVICE PARTS INFORMATION RPO DEFINITIONS: C60 - AIR CONDITIONER, FRONT, MANUAL CONTROLS C41 - HEATER, OUTSIDE AIR W/FAN AND DEFROSTER C42 - HEATER, DELUXE GU2 - AXLE REAR 2.73 RATIO GU4 - AXLE REAR 3.08 RATIO GU5 - AXLE REAR 3.23 RATIO GU6 - AXLE REAR 3.42 RATIO GT4 - AXLE REAR 3.73 RATIO K01 - FAN CLUTCH DRIVE L84 - ENGINE, 4.3L, (4.3Z) V6 LU2 - ENGINE, 4.3B, (4.3B) V6 HI-OUTPUT TBI L35 - ENGINE, 4.3L, (4.3W) CENTRAL PORT INJECTION V6 90 DEG WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Op: J3390 Labor Time: See Applicable Labor Time Guide Page 5058 Starter Solenoid: Specifications Hold-In Windings And Pull-In Windings Amperes Hold-In Windings And Pull-In Windings Amperes Hold-In Windings Pull-In Windings Starter Identification Number 10455016 13-19 A 23-30 A 10455017 13-19 A 23-30 A 10455018 13-19 A 23-30 A 10455024 10-20 A 50-65 A 10455025 10-20 A 50-65 A 10455048 10-20 A 50-65 A Page 4594 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 4865 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Electrical Specifications Throttle Position Sensor: Electrical Specifications The throttle position sensor is not adjustable on this engine but should read below 1.25 volts at closed throttle and about 4.5 volts at wide open throttle. Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Page 1831 Oil Filter: Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Page 1271 Fuse And Circuit Breaker Identification Page 6048 3. Electrical connections, as necessary. 4. New O-rings. 5. Compressor hose assembly (3) to accumulator (6). 6. Evaporator (10) to accumulator (6). Tighten - Evaporator connection to 41 Nm (30 ft. lb.). - Compressor hose connection to 41 Nm (30 ft. lb.). 7. Refrigerant to the system. - Check the system for leaks. Brake Fluid - Level & Filling Recommendations Brake Fluid: Technical Service Bulletins Brake Fluid - Level & Filling Recommendations File In Section: 05 - Brakes Bulletin No.: 00-05-22-004 Date: May, 2000 INFORMATION Subject: Brake Fluid Level and Filling Recommendations Models: 2001 and Prior Passenger Cars and Trucks Many dealers and after-market repair shops advertise multi-point fluid "top-ups" in conjunction with oil changes or regular maintenance packages. These offers often include adding brake fluid to the master cylinder reservoir. There are only two reasons why the brake fluid level in the brake reservoir might go down. The first is that the brake fluid level goes down an acceptable level during normal brake lining wear. When the linings are replaced, the fluid will return to it's original level. The second possible reason for a low fluid level is that fluid is leaking out of the brake system. If fluid is leaking, the brake system requires repair and adding additional fluid will not correct the leak. If the system was properly filled during delivery of the vehicle, no additional fluid should be required under most circumstances between brake pad and/or shoe replacements. This information can be reinforced with the customer by referring them to the Brake Fluid section of their vehicle's Owner's Manual. Guidelines GM vehicles have incorporated a variety of brake fluid reservoir styles. The following guidelines are restricted to the plastic bodied fluid reservoirs and do not affect the original service recommendations for the older style metal bodied units. You may encounter both black plastic and translucent style reservoirs. You may have reservoirs with: ^ A MAX fill mark only ^ A MIN fill mark only ^ Both MAX and MIN marks The translucent style reservoirs do not have to have the covers removed in order to view the fluid level. It is a good practice not to remove the reservoir cover unless necessary to reduce the possibility of contaminating the system. Use the following guidelines to assist in determining the proper fluid level. Important: When adding brake fluid, use Delco Supreme II(R) Brake Fluid, GM P/N 12377967 or equivalent brand bearing the DOT-3 rating only. Important: At no time should the fluid level be allowed to remain in an overfilled condition. Overfilling the brake reservoir may put unnecessary stress on the seals and cover of the reservoir. Use the following guidelines to properly maintain the fluid level. If the reservoir is overfilled, siphon out the additional fluid to comply with the guidelines below. Important: If under any circumstance the brake fluid level is extremely low in the reservoir or the BRAKE warning indicator is illuminated, the brake system should be checked for leaks and the system repaired in addition to bringing the fluid level up to the recommended guidelines outlined below. A leaking brake system will have reduced braking performance and will eventually not work at all. Important: Some vehicles have reservoirs that are very sensitive to brake fluid levels and may cause the BRAKE indicator to flicker on turns as the fluid approaches the minimum required level. If you encounter a vehicle with this concern, increase the fluid level staying within the guidelines outlined below. ^ If the reservoir has a MAX level indicator, the reservoir should be returned to the MAX marking only at the time new brake pads and/or shoes are installed. If the reservoir fluid level is at the half-way point or above do not attempt to add additional brake fluid during routine fluid checks. ^ If the reservoir has both MAX and MIN indicators, the fluid level should be maintained above the MIN indicator during routine fluid checks and returned to the MAX indication only after new brake pads and/or shoes are installed. ^ For reservoirs with only a MIN indication, the fluid level should be maintained above the MIN indicator during routine fluid checks. Return the Page 4631 The pressure bleeding equipment must be of the diaphragm type. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. Important You can expect to use two quarts of brake fluid to thoroughly bleed the system. 1. Begin by attaching the pressure bleeder adaptor J 29567 to the master cylinder (Figure 1). 2. Fill the pressure bleeder tank J 29532 at least 2/3 full with Delco Supreme No. 11 Hydraulic 8rake Fluid (GM P/N 1052535) or an equivalent DOT 3 motor vehicle brake fluid. The bleeder tank must be bled each time brake fluid is added. 3. Charge the bleeder tank to 140-170 kPa (20-25 psi) and connect the hose from the bleeder tank to the bleeder adaptor. 4. Open the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (Figure 2). 5. Attach the valve pressure bleeding tools J 39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (Figure 3) and to the combination valve (Figure 4). Tighten tool J 39177 only finger tight. 6. Open the pressure bleeder tank valve. 7. Bleed each wheel in the following sequence: ^ Right rear ^ Left rear ^ Right front ^ Left front Note: Page 6752 Figure 15 Figure 16 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). 4. Make repair. When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 3/16" (5 mm) of insulation from wire. Figure 17 e. Crimp a new terminal to the wire (Figure 17). f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal, see Figure 17). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. Figure 18 Page 4288 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure that pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. When endplay is reduced to zero, check pinion bearing preload by rotating pinion with suitable torque wrench. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Page 8191 LH Side Of Instrument Panel. On Convenience Center Applicable to: Except Bravada Page 6664 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool 4L60 & 4L60-E Transmission Transmission Speed Sensor: Specifications 4L60 & 4L60-E Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Page 7211 Figure 19 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Basic Troubleshooting Guide TROUBLESHOOTING GUIDELINES Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic theory of electricity and know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire. You should be able to read and understand a wiring diagram. The following four-step troubleshooting procedure is recommended: Step 1: Check the problem Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have narrowed down the possible causes. Step 2: Read the electrical schematic Study the schematic. Read the Circuit Description text if you do not understand how the circuit should work. Check circuits that share wiring with the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details pages.) Try to operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty. Step 3: Find the fault and repair ^ Narrow down the possible causes. ^ Use the Troubleshooting Hints. ^ Make the necessary measurements or checks as given in the System Diagnosis. ^ Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are OK, the most probable cause is component failure. Step 4: Test the repair Repeat the System Check to verify the fault has been corrected and that no other faults were induced during the repair. EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work. Step 1: Perform a system check on the headlight circuit. You may discover that both LO beams operate. In "HI," you may notice that the HI Beam Indicator comes on, but neither HI beam operates. Page 7294 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Connecting Rod/Bearing Dimensions Connecting Rod: Specifications Vin W, Rod Dimensions Vin W, Rod Dimensions Pin Clearance 0.0013-0.0019 in Note: Interference Fit Side Clearance 0.006-0.014 in Door Side Glass, Front - Binding/Track Disengagement Window Frame: All Technical Service Bulletins Door Side Glass, Front - Binding/Track Disengagement Number: 93-89-10 Section: 10 Date: JAN. 1993 Corporate Bulletin No.: 261614 ASE No.: B1 Subject: FRONT DOOR SIDE GLASS BINDING/TRACK DISENGAGEMENT Model and Year: 1982-93 S/T TRUCKS Owners of some 1982-1993 S/T vehicles may comment about the side front door glass binding during operation or the glass disengaging from the window track. These conditions may occur if the glass binds against the run assembly weatherstrip, and/or the plastic window guide separates from the glass due to improper seating during installation and/or breaks. To correct, it is necessary to replace the following items: - The side door glass with glass that has the lower rear corner rounded off. The new glass reduces binding between the glass and run assembly weatherstrip during window operation. - The run assembly weatherstrip with a weatherstrip that has additional flocking (Figure 1, Section A-A). The additional flocking helps eliminate friction between the glass and channel providing smoother window operation. A/C - Use of Alternate Refrigerants In CFC 12 Refrigerant: Technical Service Bulletins A/C - Use of Alternate Refrigerants In CFC 12 Number: 92-250-1A Section: 0A Date: AUGUST 1992 Corporate Bulletin No.: 231205 ASE No.: A7 Subject: USE OF ALTERNATE REFRIGERANTS IN CFC 12 REFRIGERANT MOBILE AIR CONDITIONERS Model and Year: GALL MODEL YEARS - ALL PASSENGER CARS AND TRUCKS INCLUDING GEO A number of inquiries have been received concerning the use of "alternate refrigerants" as a replacement for R-12 refrigerant in General Motors air conditioning systems. Regardless of any advertised claims, there are currently no substitutes for refrigerant R-12 approved by General Motors. At the present time, only new or recycled R-12 is approved for use in General Motors R-12 air conditioning systems. Based on studies performed to date, the use of "alternate refrigerants" in General Motors R-12 air conditioning systems may result in higher system pressures, higher leak rates or incompatibility with drying and sealing materials. System performance and reliability may also be affected. Service equipment manufacturers have indicated that cross-contaminating R-12 recovery/recycling equipment with "alternate refrigerants" may damage the equipment. General Motors supports the Society of Automotive Engineers recommended service procedures for recovery and recycling of R-12. The use of known "alternate refrigerants" without proper service practices for identifying vehicle systems containing these "alternate refrigerants" and dedicated recovery equipment to service those vehicles will contaminate the recycled supply of R-12 refrigerant. Contamination of the recycled R-12 refrigerant makes the refrigerant unusable for recharging air conditioning systems and could jeopardize the recycling program. At the present time, General Motors has not approved any "alternate refrigerant" for R-12 in R-12 air conditioning systems. Therefore, R-12 systems should continue to be serviced with new or recycled R-12 only. Page 1901 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 697 - Cruise control - ANTILOCK brake system. CONSTRUCTION The VSS is made up of: Permanent Magnet (PM) generator (coil), which is mounted on the transmission. - Rotor (tooth), which is mounted on the output shaft in the transmission. - VSS Buffer, which is mounted to the control module bracket. OPERATION The VSS is a Permanent Magnet (PM) generator that produces a pulsing Alternating Current (AC) voltage as each rotor tooth nears the coil. As the vehicle speed increases, the number of AC voltage pulses increase. The VSS buffer processes inputs from the VSS and outputs signal to the speedometer control module and cruise module. The VSS buffer takes the voltage pulses from the VSS and uses them to open and close four solid state output switches to ground at a rate proportional to vehicle speed. The VSS buffer is matched to the vehicle based on final drive ratio and tire size. Page 8397 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 8672 Front Inner Panel Water Deflector NOTE: Waterproof deflectors are used to seal the door inner panel, and to prevent water from entering into the body. The deflector is secured by a strip of adhesive between the deflector and the door, as well as waterproof sealing tape. REMOVE OR DISCONNECT 1. Door trim panel. 2. Plastic fasteners (when used). 3. Armrest bracket. 4. Water deflector. ^ Pull the waterproof sealing tape from the deflector. ^ Break the bond between the sealer and the door with a flat-bladed tool. INSTALL OR CONNECT 1. Water deflector strip caulking as a sealant between the deflector and the door, If needed. 2. Plastic fasteners (when used). 3. Waterproof tape. 4. Armrest bracket. 5. Door trim panel. Door Trim Panel Replacement Page 3120 EGR Valve: Service and Repair EGR Valve Cleaning WARNING: Appropriate eye protection should be worn when cleaning the EGR system to prevent injury to eyes. CAUTION: DO NOT wash the EGR valve in solvents or degreaser as permanent damage to the valve diaphragm may result. Also, sand blasting of the valve is not recommended since this can affect the operation of the valve. 1. With a wire wheel, buff the exhaust deposits from the mounting surface and around the valve. 2. Look for exhaust deposits in the valve outlet. Remove deposit build up with a screwdriver. 3. Clean the mounting surfaces of the intake manifold and valve assembly. 4. Install valve assembly using new gasket. Restraints - Driver/Passenger Seat Head Rest Information Head Restraint System: Technical Service Bulletins Restraints - Driver/Passenger Seat Head Rest Information INFORMATION Bulletin No.: 10-08-50-003A Date: March 24, 2011 Subject: Information on Driver or Passenger Seat Head Restraint Concerns with Comfort, Custom Upholstery or Other Comfort Enhancing Devices Models: 2012 and Prior GM Passenger Cars and Trucks Equipped with Adjustable Head Restraints Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 10-08-50-003 (Section 08 - Body and Accessories). Important ON A GM VEHICLE EQUIPPED WITH ADJUSTABLE HEAD RESTRAINTS, USE THE HEAD RESTRAINT COVERS, FOAM AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER OR REPOSITION THE HEAD RESTRAINT SYSTEM. ANY ALTERATIONS TO HEAD RESTRAINTS DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER DESIGN ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. You may have a customer with a concern that the head restraint is uncomfortable or sits too far forward. The front driver and passenger seats are equipped with head restraints that have been designed to help minimize injuries while still providing comfort to the occupants. Each GM vehicle has its own specifically designed head restraint. The head restraints should only be used in the vehicle for which they were designed. The head restraint will not operate to its design intent if the original foam is replaced (1) by non-GM foam or head restraint, (2) by GM foam or head restraint designed for a different vehicle, (3) by GM foam or head restraint that has been altered by a trim shop or (4) if any object, such as an aftermarket comfort enhancing pad or device, is installed. Never modify the design of the head restraint or remove the head restraint from the vehicle as this may interfere with the operation of the seating and restraint systems and may prevent proper positioning of the passenger within the vehicle. Disclaimer Page 2439 ECM QDR Check Procedure Page 7223 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 1655 Parts are currently available from GMSPO. Calibration Information for 1992 Model Year Vehicles with Sleeve Bearing Engines: Torque Specifications Page 5429 Figure 7 Figure 8 Figure 9 Figure 10 Initial Inspection and Diagnostic Overview Engine Control Module: Initial Inspection and Diagnostic Overview Diagnostic Circuit Check Specifications Intake Air Temperature Sensor: Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Page 280 Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Switch HP Engine LH Front Side Of Engine Front Of Intake Manifold Applicable to: 1992 4.3L/V6-262 HP Engine STD Engine Locations Horn Relay Installation Page 5980 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Page 2606 Throttle Position Sensor: Mechanical Specifications Throttle Position Sensor 18 in.lb Page 1888 ^ New Oil Pressure Sensor Part Numbers for the 1990-1993 models are: Parts are currently available from GMSPO Warranty Information: For vehicles repaired under warranty use labor operation N2220. Locations Forward Lights Harness, LH Side (W/Rear Wheel Antilock Brakes) Engine - Noise/Damage Oil Filter Application Importance Oil Filter: Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Left Side Knock Sensor Engine Wiring, LH Side Locations Daytime Running Lamps, I/P Wiring Page 375 Cruise Control Switch: Locations Cruise Control Components, Near Steering Column. Part Of Multi-Function Lever Fuse Panel & Flasher Locations Hazard Warning Flasher: Locations Fuse Panel & Flasher Locations The fuse block is located at the far left side of the dash panel. The hazard and turn signal flashers are located under the left side of the dash panel on the convenience center. Page 3755 PROM - Programmable Read Only Memory: Description and Operation EEPROM CAUTION: The EEPROM is soldered to the COMPUTER and cannot be serviced separately. Reprogramming of EEPROM information is necessary when replacing a COMPUTER, or when changing the engine and/or transaxle calibrations. Failure to do this will cause the vehicle to have a no start or poor running condition. It is essential that a replacement COMPUTER be reprogrammed with the correct VIN, option content, tire size, and calibration information. Reprogramming of the EEPROM is only possible with the Service Stall System (SSS) hardware available at authorized dealer locations. Check with a dealer before performing COMPUTER replacement or EEPROM reprogramming. DESCRIPTION: The term EEPROM is defined as Electronically Erasable Programmable Read Only Memory (EEPROM) in the COMPUTER. The EEPROM stores vehicle information such as engine and transaxle calibrations, vehicle identification number, programmable vehicle option content and MALF history. Vehicle information stored on the EEPROM has a major effect on how the vehicle will operate. Locations Cargo Lamp Switch: Locations LH Side Of Instrument Panel. On LH Side Of Steering Column Applicable to: Except Bravada A/C - Retrofitting R-12 Vehicles to R-134A Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Diagram Information and Instructions Clutch Switch: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. SIR - Operating Vehicle with Warning Light On Malfunction Lamp / Indicator: Customer Interest SIR - Operating Vehicle with Warning Light On File In Section: 8 - Chassis/Body Electrical Bulletin No.: 83-81-34 Date: March, 1999 INFORMATION Subject: Operating Vehicle with Supplemental Inflatable Restraint (SIR) Warning Light Illuminated Models: 1999 and Prior Passenger Cars and Light Duty Trucks with SDM Controlled Air Bag System The AIR BAG warning light is the key to driver notification of Supplemental Inflatable Restraint (SIR) system malfunctions. When the warning light remains illuminated or continues to flash, one or more of the following conditions may occur if vehicle operation is continued. ^ Non-deployment of the air bags in the event of a crash. ^ Deployment of the air bags without a crash. ^ Deployment of the air bags in crashes less severe than intended. If an AIR BAG warning light is illuminated or flashing, you should advise the customer of these possibilities and that the vehicle should be serviced right away. Page 7357 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Locations Cruise Controller: Locations Cruise Control Components, Near Steering Column. Under LH Side Of I/P Page 3159 Fuel Pressure Test Port: Service and Repair Fuel Pressure Connection CLEAN Area around fuel pressure connection with GM X-30A or equivalent. REMOVE OR DISCONNECT - Negative battery terminal. - Relieve fuel system pressure. - Fuel pressure connection and seal. Discard seal. INSTALL OR CONNECT - New seal on fuel pressure connection. - Fuel pressure connection in fuel rail. Tighten Fuel pressure connection assembly to 10.0 N-m (88 lb. in.). - Tighten fuel filler cap. - Negative battery terminal. INSPECT - Turn ignition switch to the "ON" position for two seconds, then turn to the "OFF" position for ten seconds. Again turn to the "ON" position, and check for fuel leaks. NOTE Any time the battery is disconnected, the programmed position of the IAC valve pintle is lost, and replaced with a default value. To return the IAC valve pintle to the correct position, perform the following procedure: - Disconnect negative battery for at least ten seconds to clear control module memory. (Ensure ignition is "OFF".) - Reconnect negative battery cable. - "START" engine and allow engine to reach operating temperature. Check for proper idle operation. Page 39 Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Page 1152 Select and install the proper R-134a fittings (shown in Figure 4) from the chart below, based on how the ACR4 couplers will attach. Also, remember to check for proper hood clearance with the conversion fittings. Try the straight fittings first. The two-piece high side fitting is used when the existing fitting is screwed into the pipe fitting (some 1992, and nearly all 1993 models, use these fittings). Use the 90° elbow if the straight fitting does not allow the ACR4 couplers to connect. Fitting Type High Side Low Side Straight 52467941 52467943 Straight Two-piece 52467324 N/A 90° Elbow 52469054 52469055 The fittings should be installed as follows: a. Remove the caps from the R-12 fittings. Remove any dirt or grease from the port threads using the thread cleaning wire brush, J 41265. Inspect the fittings for thread damage. If any damage is found, use the port thread restorer (J 41266 low side, J 41267 high side) to repair the thread. For the two-piece fitting, remove the existing R-12 fitting and discard it. Use tool J 38704A (previously released, not part of the above kit) to remove the fitting. Make sure to hold the line securely to prevent damage when removing the existing fitting. If the fitting cannot be removed easily, use the saddle clamp valve listed below and seal the R-12 port and cap permanently. b. Install the selected fitting onto the existing R-12 fitting. Leave the valve core in the straight fittings, and remove the valve core when using the 90° fittings. If the valve cores need to be removed at a later time, they can be removed with the straight conversion fittings in place. On the low side straight fitting, use the J 34611-A tool to remove the core pin in the conversion fitting, then remove the core valve from the original R-12 fitting. Always recover the charge before valve core removal. Page 4936 Figure 11 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 12 Figure 13 Figure 14 Page 2946 Knock Sensor: Description and Operation Electronic Spark Control Circuit Knock Sensor (KS) Sensor PURPOSE Varying octane levels in today's gasoline can cause detonation (also known as spark knock) in an engine. The Knock Sensor (KS) system has various knock sensors that are used on all engines except the 2.5L. The KS system reduces spark knock (detonation) in the engine. This allows the engine to have a maximum spark advance for improved driveablity and fuel economy. CONSTRUCTION This KS system has three main components: - KS Module. - Knock sensor - ECM OPERATION The knock sensor detects abnormal vibration (spark knocking) in the engine. The knock sensor is mounted in the engine block near the cylinders. The KS module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the Ignition Control (IC) to reduce spark knocking. The KS module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the knock sensor. This allows the ECM to maintain maximum timing advance under various engine load conditions. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards IC to reduce spark knock. Clutch Pedal Switch Clutch Switch: Locations Clutch Pedal Switch Brake Pedal Switches. On Clutch Pedal Support Page 77 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 8198 Hazard Warning Flasher: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Figure 21 Figure 22 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. Page 1234 1. Begin by opening the internal bleed screws 1/4 to 1/2 turn, on each side of the BPMV (figure 2). 2. Attach the valve pressure bleeding tool J39177 to the left and right high pressure accumulator bleed valve stems of the BPMV (figure 3). Tighten tool J39177 only finger tight. NOTE: It is not necessary to attach bleeding tool J39177 to the combination valve when using the manual bleed procedure. 3. Bleed each wheel in the following sequence: - Right rear - Left rear - Right front - Left front NOTE: Rear wheel bleeder valves are 5/16 in. (8 mm) and front wheel bleeder valves are 10 mm. NOTE: A clear plastic hose can be attached to the bleeder valve and immersed into a container partially filled with clean brake fluid. 4. Slowly apply the brake pedal one time and hold. 5. Loosen the bleeder valve to purge the air from the wheel cylinder/caliper. 6. Tighten the bleeder valve and slowly release the pedal. 7. Wait 15 seconds. 8. Be sure to check the master cylinder fluid level after 4-5 strokes to avoid running dry. 9. Repeat steps 4 through 8, until all air is purged from the wheel cylinder/caliper. NOTE: It may be necessary to repeat this sequence as many as 15 to 20 times per wheel. 10. Fill the master cylinder to the proper level and replace lid. 11. CLOSE and tighten the two BPMV internal bleed screws (Figure 2) to 7 N-m (60 lbs.in.). 12. Remove the valve pressure bleeding tools J39177 from the BPMV high pressure accumulator bleed valve stems and the combination valve. 13. With the ignition switch "ON" and the engine off, bleed the pump and pressure (lower) portion of the BPMV by performing six ABS function tests with the Tech-1. IMPORTANT: DURING THE TECH-1 FUNCTION TESTS, THE BRAKE PEDAL MUST BE FIRMLY DEPRESSED. THIS WILL PUSH ANY AIR FROM THE CONTROL AREA OF THE BPMV INTO THE BRAKE SYSTEM. 14. Finally, rebleed the four wheel cylinder/calipers again, to purge any remaining air put into the system during the function tests. Use either the pressure bleed or manual bleed for this step. IMPORTANT: DO NOT OPEN THE BPMV INTERNAL BLEED SCREWS OR DEPRESS THE HIGH PRESSURE ACCUMULATOR BLEED VALVES WHEN REBLEEDING AFTER THE FUNCTION TESTS. 15. Tighten all four wheel cylinder/caliper bleeder valves to 7 N-m (60 lbs.in.). 16. Fill the master cylinder to the proper level with brake fluid. 17. Apply firm pressure to the brake pedal and evaluate the brake pedal feel. IMPORTANT: MAKE SURE YOU HAVE A GOOD, HARD BRAKE PEDAL BEFORE ATTEMPTING TO MOVE THE VEHICLE. 18. Repeat the entire brake bleed procedure if necessary. Warranty Information LABOR OP. MODEL H0700 S/T H0700 M/L H0700 C/K H0700 G Use applicable labor time guide for labor hours. Page 1967 Oil Pressure Gage Is Inaccurate Page 3908 Fluid - A/T: Technical Service Bulletins A/T - DEXRON III Fluid Introduction File In Section: 0 - General Information Bulletin No.: 57-02-01 Date: March, 1995 SERVICE MANUAL UPDATE Subject: Section 0 - General Information - DEXRON(R)-III Transmission Fluid Introduction Models: 1995 and Prior Passenger Cars and Trucks General Motors has phased in a new automatic transmission fluid, DEXRON(R)-III, that does not need replacing under normal service. DEXRON(R)-III is designed to help the transmission deliver the best possible performance under all conditions. Refer to Figure 1. The improvements in DEXRON(R)-III include better friction stability, more high temperature oxidation stability and better material compatibility. DEXRON(R)-III has the same low temperature fluidity as DEXRON(R)-IIE, for better transmission performance in cold weather. DEXRON(R)-IIE and DEXRON(R)-III are fully compatible. DEXRON(R)-III is fully compatible with any General Motors passenger vehicle or light truck with automatic transmission and built since 1949. Dealers should require their supplier to include the DEXRON(R)-III license number on all automatic transmission fluid invoices. Starting February 1, 1994 DEXRON(R)-III was phased into all North American assembly plants. DEXRON(R)-III fluid is available from GMSPO (see fluid numbers below): U.S. 1 Quart 12346143 Page 6248 - To check the position of the axial plate on the shaft, remove the clutch driven plate and measure the distance between the front head extension and the flat shoulder on the shaft with a wire gage. The clearance should be 0.66-1.9 mm (0.026-0.075-inch). - If the shaft has been pushed back in the axial plate (measurement greater than 1.9 mm (0.075-inch), disassemble the compressor and replace the shaft and axial plate assembly, thrust races and thrust bearings. - If there is too much or not enough air gap between the drive and driven plates, check for shaft dislocation. It will not be possible to service the compressor if the carbon seat is not seating against the seal seat. 9. Shaft nut (1) with J 9399-A. - Place the compressor in a horizontal position with the oil sump down. - Rotate the compressor shaft by hand. - Replace shaft nut (1) with a new one. Page 709 Oil Pressure Switch (For Fuel Pump): Service and Repair Oil Pressure Switch REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Page 8106 Symbol Identification Page 7634 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Page 7882 Page 5035 (ECM), should be tested only with a 10-megaohm or higher impedance digital multimeter. When measuring resistance with a digital multimeter, the vehicle Battery should be disconnected. This will prevent incorrect readings. Digital meters apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading. Diodes and solid state components in a circuit can cause an ohmmeter to give a false reading. To find out if a component is affecting a measurement, take a reading once, reverse the leads and take a second reading. If the readings differ, the solid state component is affecting the measurement. FUSED JUMPER WIRE A fused jumper is available with small clamp connectors providing adaptation to most connectors without damage. This fused jumper wire is supplied with a 20 amp fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being tested. CAUTION: A fused jumper may not protect solid state components from being damaged. SHORT FINDER Short Finders are available to locate hidden shorts to ground. The short finder creates a pulsing magnetic field in the shorted circuit and shows you the location of the short through body trim or sheet metal. FUSE TESTER A simple tester can detect a blown fuse. To check a fuse, the tester is applied directly to the fuse in the Fuse Block. Two probes contact the fuse, either into the slots of a flat fuse or to the metal ends of a glass fuse. With power on, a red LED in the tester lights if the fuse is open. The handle of the tester is a tool for removing either type of fuse. Handling and Measuring Procedures Fig. 1 ESD Symbol Fig. 2 Typical Schematic W/ESD Symbol ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES All ESD sensitive components are Solid State and the following information applies to them. The ESD symbol, Fig. 1, is used on schematics to indicate which components are ESD sensitive, Fig. 2. When handling any electronic part, the service technician should follow the guidelines below to reduce any possible electrostatic charge build-up on the service technician's body and the electronic part in the dealership. If it is not known whether or not a component is ESD sensitive, assume that it is. HANDLING PROCEDURES 1. Always touch a known good ground before handling the part. This should be repeated while handling the part and more frequently after sliding across the seat, sitting down from a standing position or walking the distance. 2. Avoid touching electrical terminals of the part, unless so instructed by a written diagnostic procedure. 3. When using a voltmeter be sure to connect the ground lead first. 4. Do not open package until it is time to install the part. 5. Before removing the part from its package, ground the package to a known good ground on the vehicle. MEASURING PROCEDURES The circuits shown within the boxes are greatly simplified. Do not troubleshoot by measuring resistance at any terminal of these devices unless so instructed by a written diagnostic procedure. Due to the simplification of the schematics, resistance measurements could be misleading, or could lead to electrostatic discharge. Page 7863 Page 1383 Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. Final Inspection 1. After remounting and inflating the tire, check both beads, the repair and the valve with a water and soap solution in order to detect leaks. 2. If the tire continues to lose air, the tire must be demounted and reinspected. 3. Balance the tire and wheel assembly. Refer to Tire and Wheel Assembly Balancing - OFF Vehicle. For additional tire puncture repair information, contact: Rubber Manufacturers Association (RMA) Disclaimer Warranty - Rail Dust Removal & Chemical Spotting Labor Paint: All Technical Service Bulletins Warranty - Rail Dust Removal & Chemical Spotting Labor File In Section: Warranty Administration Bulletin No.: 72-05-11 Date: December, 1997 WARRANTY ADMINISTRATION Subject: Clarification of Rail Dust Removal (A5575-A5580) and Chemical Spotting (A5541-A5544) Labor Operations Models: All Past and Future Passenger Cars and Light Duty Trucks The purpose of this Warranty Administration Bulletin is to clarify the usage, limits and guidelines for the proper use of the above subject labor operations. The above subject labor operations were introduced to correct paint imperfections caused by fallout that occurred either during shipment to the dealer or within the first 12 months or 12,000 miles (20,000 kms) of vehicle ownership. GM vehicle owners are informed that although no defect in the factory applied paint causes this, GM will repair, at no charge to the owner, the surfaces of new vehicles damaged by fallout condition within 12 months or 12,000 miles (20,000 kms) whichever occurs first. Effective with repair orders dated on or after December 1, 1997, labor operations A5575-A5580 Rail Dust Removal and A5541 through A5544 Chemical Spotting will be limited to within the first 12 months or 12,000 miles of the Base Vehicle Warranty (20,000 kms) whichever occurs first. Page 2655 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 315 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Page 4332 D. Measure, using an inch-pound torque wrench, the amount of torque required to turn the pinion. Record this measurement for reassemble. This will give combined pinion bearing, seal, carrier bearing, axle bearing, and seal preload. 3. Pinion flange nut and washer. - Use J 8614-01 to hold the pinion flange. 4. Pinion flange. - Have a suitable container in place to catch lubricant. 5. Oil seal using a seal removal tool. - Do not damage the carrier. Inspect 1. Seal surface of the pinion flange for tool marks, nicks, or damage such as a groove worn by the seal. Replace the flange if necessary. 2. Carrier bore for burrs that might cause leaks around the outside of the seal. INSTALL OR CONNECT - Tools Required: J 8614-01 Companion Flange Holder - J 23911 Pinion Oil Seal Installer 1. New seal using J 23911. 2. Seal lubricant to the outside of the pinion flange and the sealing lip of the new seal. 3. Pinion flange. Important: Do not attempt to hammer the pinion flange onto the pinion stem. 4. Washer and nut. - Tighten: A. The nut on the pinion stem as close to the original marks as possible without going past the mark. Use the reference mark and the thread count as reference. B. The nut a little at a time and turn the pinion flange several times after each tightening to set the rollers. Measure - Using an inch-pound torque wrench, the torque required to rotate the pinion. Compare this with the required rotating torque recorded earlier. Continue tightening and measuring a little at a time until the same preload is achieved. Important: If the original preload torque value was less than 3 inch lbs. then reset the torque specification to 3-5 inch lbs. - Align the propeller shaft with the alignment marks made previously. Page 3849 If clutch debris is found, it is also very important to inspect the Pressure Control (PC) solenoid valve (377) fluid screens. Clean or replace the PC solenoid (377) as necessary. It is also important to flush and flow check the transmission oil cooler using J45096. Refer to SI Automatic Transmission Oil Cooler Flushing and Flow Test for the procedure. The notches above each sprag must point up as shown when assembled into the outer race. Bearing Assembly, Input Sun Gear Snap Ring, Overrun Clutch Hub Retaining Hub, Overrun Clutch Wear Plate, Sprag Assembly Retainer and Race Assembly, Sprag Forward Sprag Assembly Retainer Rings, Sprag Assembly Outer Race, Forward Clutch Washer, Thrust (Input Carrier to Race) The following information applies when this sprag is used in 1982-86 transmissions. The new design sprag can be used on models 1982 through 1986, by replacing the entire assembly (637 - 644). Individual components are NOT Page 7470 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Page 6657 Circuit Protection Devices DESCRIPTION: The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a current requirement that is higher than normal. This overload could be caused by a short circuit or system malfunction. The short circuit could be the result of a pinched or cut wire or an internal device short circuit, such as an electronic module failure. The circuit protection device is only applied to protect the wiring assembly, and not the electrical load at the end of the assembly. For example, if an electronic component short circuits, the circuit protection device will assure a minimal amount of damage to the wiring assembly. However, it will not necessarily prevent damage to the component. CIRCUIT PROTECTION DEVICES There are three basic types of circuit protection devices: Circuit Breaker, Fuse and Fusible Link. CIRCUIT BREAKERS A circuit breaker is a protective device designed to open the circuit when a current load is in excess of rated breaker capacity. If there is a short or other type of overload condition in the circuit, the excessive current will open the circuit between the circuit breaker terminals. There are two basic types of circuit breakers used in GM vehicles: cycling and non-cycling. CYCLING CIRCUIT BREAKER The cycling breaker will open due to heat generated when excessive current passes through it for a period of time. Once the circuit breaker cools, it will close again after a few seconds. If the cause of the high current is still present it will open again. It will continue to cycle open and closed until the condition causing the high current is removed. NON-CYCLING CIRCUIT BREAKER There are two types of non-cycling circuit breakers. One type is mechanical and is nearly the same as a cycling breaker. The difference is a small heater wire within the non-cycling circuit breaker. This wire provides enough heat to keep the bimetallic element open until the current source is removed. The other type is solid state, known as an Electronic Circuit Breaker (ECB). This device has a Positive Temperature Coefficient. It increases its resistance greatly when excessive current passes through it. The excessive current heats the ECB. As it heats, its resistance increases, therefore having a Positive Temperature Coefficient. Eventually the resistance gets so high that the circuit is effectively open. The ECB will not reset until the circuit is opened, removing voltage from its terminals. Once voltage is removed, the circuit breaker will re-close within a second or two. FUSES Fig. 1 Fuse Devices Shift Rod Swivel Attaching Nuts Shift Linkage: Specifications Shift Rod Swivel Attaching Nuts Shift Rod Swivel Attaching Nut ............................................................................................................ ................................................................. 18 Ft.Lbs. Page 3850 interchangeable. Important: The wear plate (640) and input thrust washer (660) are not required with the new sprag. Use of the thrust washer and wear plate with the new sprag assembly will cause a misbuild (correct end play cannot be obtained). Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Page 5372 Symbol Identification Page 8273 Testing for Short with Self-Powered Test Light or Ohmmeter With a Self-Powered Test Light or Ohmmeter 1. Remove the blown fuse and disconnect the Battery and load. 2. Connect one lead of a self-powered test light or ohmmeter to the fuse terminal on the load side. 3. Connect the other lead to a known good ground. 4. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the self-powered test light or ohmmeter. 5. When the self-powered test light glows, or the ohmmeter registers, there is a short to ground in the wiring near that point. Fuses Powering Several Loads 1. Find the schematic under FUSE BLOCK DETAILS for the fuse that has blown. 2. Open the first connector or switch leading from the fuse to each load. 3. Replace the fuse. ^ If the fuse blows, the short is in the wiring leading to the first connector or switch. Use a test light or meter as described previously. ^ If fuse does not blow, refer to next step. 4. Close each connector or switch until the fuse blows in order to find which circuit the short is in. Connect test lamp or meter at the connector to the suspect circuit (disconnected) rather than at the fuse terminals. Troubleshooting Tools TEST LIGHT/VOLTMETER Use a test light to check for voltage. A Test Light is made up of a 12 volt light bulb, with a pair of leads attached. After grounding one lead, touch the other lead to various points along the circuit where voltage should be present. When the bulb goes on, there is voltage at the point being tested. A voltmeter can be used instead of a test light. While a test light shows whether or not voltage is present, a voltmeter indicates how much voltage is present. An increasing number of circuits include solid state control modules. One example is the Electronic Control Module (ECM). Voltages in these circuits should be tested only with a 10-megaohm or higher impedance digital voltmeter or multimeter. Unless directed to within the diagnostics, never use a test light on circuits that contain soled state components, since damage to these components may result. When testing for voltage or continuity at the connection, it is not necessary to separate the two halves of the connector. Unless testing a Weather Pack(R) connector, always probe the connector from the back. Always check both sides of the connector. An accumulation of dirt and corrosion between contact surfaces is sometimes a cause of electrical problems. CONNECTOR TEST ADAPTERS A GM connector Adapter Kit (J 35616) is available for making tests and measurements at separated connectors. This kit contains an assortment of probes which mate with many of the types of terminals you will see. Avoid using paper clips and other substitutes since they can damage terminals and cause incorrect measurements. SELF-POWERED TEST LIGHT A self-powered test light can be used to check for continuity. This tool is made up of a light bulb, Battery and two leads. If the leads are touched together, the bulb will go on. A self-powered test light is used only on an unpowered circuit. First remove the fuse which feeds the circuit you're working on. Select two specific points along the circuit through which there should be continuity. Connect one lead of the self-powered test light to each point. If there is continuity, the test light circuit will be completed and the bulb will go on. Never use a self-powered test light on circuits that contain solid state components, since damage to these components may result. OHMMETER An ohmmeter can be used instead of a self-powered test light. The ohmmeter shows how much resistance there is between two points along a circuit. Low resistance means good continuity. Circuits which include any solid state control modules, such as the Electronic Control Module Locations Timing Mark Recall 93V008000: Engine Cooling Fan Blade Breaks Fan Blade: All Technical Service Bulletins Recall 93V008000: Engine Cooling Fan Blade Breaks The engine cooling fan blades break as a result of fatigue and/or vehicle induced stress. If the blade breakage occurs while the hood is open, a person working under the hood or in the vicinity of the vehicle could be struck and injured by the blade segment. Install a newly designed fan assembly. System: Engine. Vehicle description: Light trucks with 2.5L engines without air conditioning. Page 7459 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 5184 Fig. 2 Fuse Rating and Color The most common method of automotive wiring circuit protection is the fuse, Fig. 1. A fuse is a device that, by the melting of its element, opens an electrical circuit when the current exceeds a given level for a sufficient time. The action is non-reversible and the fuse must be replaced each time a circuit is overloaded or after a malfunction is repaired. Fuses are color coded. The standardized color identification and ratings are shown in Fig. 2. For service replacement, non-color coded fuses of the same respective current rating can be used. Examine a suspect fuse for a break in the element. If the element is broken or melted, replace the fuse with one of equal current rating. There are additional specific circuits with in-line fuses. These fuses are located within the individual wiring harness and will appear to be an open circuit if blown. AUTOFUSE The Autofuse, normally referred to simply as "Fuse," is the most common circuit protection device in today's vehicle. The Autofuse is most often used to protect the wiring assembly between the Fuse Block and the system components. MAXIFUSE The Maxifuse was designed to replace the fusible link and Pacific Fuse Elements. The Maxifuse is designed to protect cables, normally between the Battery and Fuse Block, from both direct short circuits and resistive short circuits. Compared to a fusible link or a Pacific Fuse Element, the Maxifuse performs much more like an Autofuse, although the average opening time is slightly longer. This is because the Maxifuse was designed to be a slower blowing fuse, with less chance of nuisance blows. MINIFUSE The Minifuse is a smaller version of the Autofuse and has a similar performance. As with the Autofuse, the Minifuse is usually used to protect the wiring assembly between a Fuse Block and system components. Since the Minifuse is a smaller device, it allows for more system specific fusing to be accomplished within the same amount of space as Autofuses. PACIFIC FUSE ELEMENT The Pacific Fuse Element was developed to be a replacement for the fusible link. Like a fusible link, the fuse element is designed to protect wiring from a direct short to ground. Though the element is easier to service and inspect than a fusible link, it has limited use and will be replaced by Diagram Information and Instructions Vanity Lamp: Diagram Information and Instructions Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Page 4806 Wheel Cylinder: Service and Repair Installation For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics 1. Wipe end of hydraulic line to remove any foreign matter, then place wheel cylinder in position. Enter tubing into cylinder and start threads on fitting. 2. Install wheel cylinder bolts and tighten to backing plate. 3. Tighten brake line. 4. Install brake shoes. 5. Install brake drum. 6. Install wheel and tire assembly. 7. Bleed the brake system. 8. Adjust parking brake. Page 4244 Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 1. Remove disc pack and shim from side gear, keeping components in order. 2. Clean and inspect components, and replace any that are damaged, deformed or excessively worn. If side gear must be replaced, refer to SIDE GEAR SHIM SELECTION for shim selection prior to case assembly. If side gear hub is scored or worn, inspect bore in case and replace assembly if bore is damaged or worn. 3. Alternately assemble eared discs and splined discs on side gear hub, starting with eared disc as shown in Fig. 8. 4. Install original shim or replacement shim of same thickness if original side gear is being used. Page 5427 Figure 23 c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. Figure 2 Page 7530 Voltage Check TESTING FOR VOLTAGE 1. Connect one lead of a test light to a known good ground. When using a voltmeter, be sure the voltmeter's negative lead is connected to ground. 2. Connect the other lead of the test light or voltmeter to a selected test point (connector or terminal). 3. If the test light illuminates, there is voltage present. When using a voltmeter, note the voltage reading. Continuity Check through a Switch TESTING FOR CONTINUITY 1. Remove the fuse to the circuit involved. 2. Connect one lead of a self-powered test light or ohmmeter to one end of the part of the circuit you wish to test. 3. Connect the other lead to the other end of the circuit. 4. If the self-powered test light glows, there is continuity. When using an ohmmeter, low or no resistance means good continuity. Page 2183 Engine Sensor Locations. LH Front Of Engine Applicable to: Except 4.3L/V6-262 HP & 4.3L/V6-262 Turbo Engines Page 1620 Torque adjustable lash service studs to 47 N-m (35 lbs.ft.). Install rocker arms P/N 10066063. Install ball P/N 14091813 and nut P/N 477212. Using the valve lash procedure for adjustable lash valvetrain (pressed-in rocker arm stud procedure) outlined in the service manual, lash the valves to 1.75 turns down from zero lash (not 1 turn). NOTE: 1991 net lash LB4 engines may be converted to an adjustable lash system using these same part numbers. However, if the 1991 lifters are retained, the valves should be lashed to 1 turn down from zero lash. SERVICE PARTS INFORMATION: Parts are currently available from GMSPO. WARRANTY INFORMATION: Note: Labor operations are coded to base vehicle coverages in the warranty system. Page 8403 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Page 354 Step 1: Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). If the harness has a black plastic conduit, simply pull out the desired wire. Step 2: Cut the Wire Begin by cutting as little wire off the harness as possible. You may need the extra length of the wire later if you decide to cut more wire off to change the location of a splice. You may have to adjust splice locations to make certain that each splice is at least 40 mm (1-1/2") away from other splices, harness branches or connectors. Step 3: Strip the Insulation Fig. 6 Wire Size Conversion Table When replacing a wire, use a wire of the same size as the original wire or larger. The schematics list wire size in metric units. See table, Fig. 6, for the commercial (AWG) wire sizes that can be used to replace each metric wire size. Each AWG size is either equal to or larger than the equivalent metric size. To find the correct wire size either find the wire on the schematic and convert the metric size to the AWG size, or use an AWG wire gage. If you aren't sure of the wire size, start with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Be careful to avoid nicking or cutting any of the wires. Step 4: Crimp the Wires Page 7443 Fig. 6 Wire Size Conversion Table Step 3: Strip the Insulation If it is necessary to add a length of wire to the existing harness, be certain to use the same size as the original wire, see Fig. 6. To find the correct wire size either find the wire on the schematic and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in the wire stripper and work down until a clean strip of the insulation is removed. Strip approximately 7.5 mm (5/16 in.) of insulation from each wire to be spliced. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart Fig. 13 Hand Crimp Tool Page 6417 - Meets GM contamination sensitivity requirements - Self calibrating - Micro-processor controlled - Audio alarm alerts technician Other Refrigerant Identifiers are being advertised which may be available this A/C season. However, ONLY the Kent-Moore J 39851 R12 "Pureguard" meets General Motors' current specifications which ensure recovered refrigerant is compatible with General Motors vehicles and General Motors approved recovery systems. An R134a Pureguard Refrigerant Identifier is currently under development and is anticipated to be available in early 1995. The contamination of R134a refrigerant is not expected to be a concern until the program to retrofit R12 vehicles to R134a becomes more widely used. Future bulletins will be issued to address the recovery and disposal of contaminated refrigerant. Page 3722 PROM - Programmable Read Only Memory: Application and ID Additional PROM Information New ECM PROMs for GM vehicles may be released for service at any time. The information in this system is accurate to the best of the publisher's knowledge and the publication date of the disk. Before ordering a PROM, consult with a GM parts and service dealer to verify the latest part number information. Scanner PROM ID information for earlier-model vehicles (1980-83) is less complete than for later models. To accurately identify PROM's in earlier vehicles, it may be necessary to check the external PROM code marked on the PROM. General Motors has often recommended that dealership technicians check the PROM history of a vehicle and install the most recent PROM revision before performing other diagnostic operations. Each succeeding PROM revision for a specific vehicle includes all previous revisions. Therefore, whenever you consider changing a PROM, review the entire PROM history to see if any revision covered the current driveability problem. Installing the most recent PROM revision may be impractical however for an independent service facility, particularly if the latest PROM revision does not address the specific driveability problem of the vehicle. Page 7849 Fuel Gauge Sender: Testing and Inspection Diagnostic Circuit Check Page 3731 [32] Requires Thermac Sensor P/N 8997916. [33] For Federal - Use 01227729 (SCAN I.D. = 7729). For California - Use 01227728 (SCAN I.D. = 7728). [34] Use 01227629 (SCAN I.D. = 7629) only to resolve surge or chuggle. [35] Use 01227381 (SCAN I.D. = 7381) only to resolve chuggle. [36] Use 01227386 (SCAN I.D. = 7386) only to resolve chuggle. [37] Retrofit PROM - Does not supersede the regular replacement service PROM. To be used only as required to resolve cases of chuggle. [38] Retrofit PROM - Supersedes all previous service PROM part numbers. To be used as both the regular service replacement (PROM-damaged or defective), and to resolve cases of chuggle. [39] Retrofit PROM - Supersedes all previous service PROM part numbers. To be used as both the regular service replacement (PROM-damaged or defective), and to resolve cases of chuggle, detonation, or flatness. [40] Retrofit PROM - Does not supersede the regular replacement service PROMS. To be used only as required to resolve cases of chuggle, detonation, or flatness. [41] Need EGR valve P/N 17111577 (Federal only). [42] For use with P215/65 tires - use 01228290 (SCAN I.D. = 8290). For use with P235/60, P245/50 tires - use 01228291 (SCAN I.D. = 8291). [43] For use with P215/65 tires - use 01228292 (SCAN I.D. - 8292). For use with P235/60, P245/50 tires - use 01228293 (SCAN I.D. = 8293). [44] Use 16143570 (SCAN I.D. = 3531) for hot hard restart (Requires Fuel Pump P/N 25115764, Fuel Sender P/N 25093526). Use 16143459 (SCAN I.D. = 3571) for Code 42, Spark Knock, High Idle. [45] Use 16143455 (SCAN I.D. = 3511) for hot hard restart (Requires Fuel Pump P/N 25115764, Fuel Sender P/N 25093526). Use 16143453 (SCAN I.D. = 3501) for Code 42, Spark Knock, High Idle. [46] Use 16143575 (SCAN I.D. = 3541) for hot hard restart (Requires Fuel Pump P/N 25115764). Use 16143460 (SCAN I.D. = 3581) for Code 42, Spark Knock, High Idle. [47] Use 16143580 (SCAN I.D. = 3551) for hot hard restart (Requires Fuel Pump P/N 25115764). Use 16143462 (SCAN I.D. = 3591) for Code 42, Spark Knock, High Idle. [48] Use 16143457 (SCAN I.D. = 3521) for hot hard restart (Requires Fuel Pump P/N 25115925, Fuel Sender P/N 25092778). Use 16143466 (SCAN I.D. = 3481) for Code 42, Spark Knock, High Idle. [49] Use 16143452 (SCAN I.D. = 3491) for hot hard restart (Requires Fuel Pump P/N 25115925, Fuel Sender P/N 25092778). Use 16143463 (SCAN I.D. = 3451) for Code 42, Spark Knock, High Idle. [50] Needs air injection service kit (P/N 10115773) and new vehicle emission control label. Locations Power Steering Pressure Switch Wiring Body - TPO Fascia Cleaning Prior to Painting Paint: All Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer Page 631 Knock Sensor: Description and Operation Electronic Spark Control Circuit Knock Sensor (KS) Sensor PURPOSE Varying octane levels in today's gasoline can cause detonation (also known as spark knock) in an engine. The Knock Sensor (KS) system has various knock sensors that are used on all engines except the 2.5L. The KS system reduces spark knock (detonation) in the engine. This allows the engine to have a maximum spark advance for improved driveablity and fuel economy. CONSTRUCTION This KS system has three main components: - KS Module. - Knock sensor - ECM OPERATION The knock sensor detects abnormal vibration (spark knocking) in the engine. The knock sensor is mounted in the engine block near the cylinders. The KS module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the Ignition Control (IC) to reduce spark knocking. The KS module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the knock sensor. This allows the ECM to maintain maximum timing advance under various engine load conditions. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards IC to reduce spark knock. Page 4604 Fig. 16 The Untwisted Conductors Untwist the conductors. Then, prepare the splice by following the splicing instructions for copper wire presented earlier. Remember to stagger splices to avoid shorts, Fig. 16. Step 4: Re-assemble the Cable Fig. 17 The Re-assembled Cable After you have spliced and taped each wire, rewrap the conductors with the mylar tape. Be careful to avoid wrapping the drain wire in the tape. Next, splice the drain wire following the splicing instructions for copper wire. Then, wrap the drain wire around the conductors and mylar tape, Fig. 17. Step 5: Tape the Cable Fig. 18 Proper Taping Tape over the entire cable using a winding motion, Fig. 18. This tape will replace the section of the jacket you removed to make the repair. Locations Turn And Hazard Lamp Flashers Page 7394 Fig. 1 Typical Headlights Schematic Step 2: Read the headlights electrical schematic, see Fig.5 This is the step that will save time and labor. Remember, it is essential to understand how a circuit should work, before trying to figure out why it doesn't. After you understand how the circuit should operate, read the schematic again, this time keeping in mind what you have learned by operating the circuit. Since both LO beams work, you know that the Headlight Switch, the YEL wire, the LO contacts of the Headlight Dimmer Switch, terminal "1E" of C100, the TAN wires and grounds G105 and G109 are all good. Furthermore, since you saw that the HI Beam Indicator came on when the headlight Dimmer Switch was moved to "HI," you know that the HI contacts of the Headlight Dimmer Switch and the LT GRN wire between the Headlight Dimmer Switch and C100 are good. At this point, you could test for voltage at the RH Headlamp with the Headlight Dimmer Switch in "HI." However, it is extremely unlikely that the HI beam filaments have burned out in both headlamps, or that both headlamps connections are bad. The cause must be a bad connection at C100, or a break in the LT GRN wire between C100 and the RH Headlamp. You have quickly narrowed the possible causes down to one specific area, and have done absolutely no work on the vehicle itself. Step 3: Find the fault and repair it. Using the Component Location List and the corresponding figure, you can quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair. Step 4: Check the repair by performing a system check on the headlights circuit. This, of course, means making sure that both HI beams, both LO beams and the HI Beam Indicator are all working. Now suppose that the symptoms were different. You may have operated the Headlamps and found that the LO beams were working, but neither the HI beams nor the HI Beam Indicator were working. Looking at the schematic, you might conclude that it is unlikely that both HI beam filaments and the HI Beam Indicator have all burned out at once. The cause is probably the Headlight Dimmer Switch or its connector. Checking Terminal Contacts Page 3241 - An updated engine control calibration, or service procedure, may be available to make the engine less susceptible to low volatility fuels. 3. If basic checks do not reveal a vehicle fault, then advise the customer that fuel quality may be an issue. Recommend the following actions: Change brands of fuel - Use 87 octane gasoline, unless the vehicle is designed for premium gasoline. - Try to empty the fuel tank as much as practical before refilling. - Run a minimum of three tanks of new fuel before returning for service. 4. If above steps are ineffective, do not proceed with additional vehicle diagnosis and/or parts replacement until the fuel tank has been drained and refilled with a known good quality gasoline AT THE DEALERSHIP. 5. If the problem remains refer to service manual, service bulletins and/or technical assistance. Page 7466 Fig. 7 Deformation of a Typical Metri-Pak Series Female Terminal DESCRIPTION When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to GM Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, see Fig. 7, causing an open or intermittently open circuit. PROCEDURES: Follow the procedure below to check terminal contact. 1. Separate the connector halves. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. Armrest Front Door Panel: Service and Repair Armrest Front Door Trim Panel REMOVE OR DISCONNECT 1. Screws securing the armrest to the door trim. 2. Armrest from the door trim. ^ Slide the armrest towards the rear of the door, and then, lift the armrest from the door. INSTALL OR CONNECT 1. Armrest to the door trim. ^ Place the armrest retaining clips in the slots on the door panel. ^ Slide the armrest toward the front of the door unit the holes in the armrest align with the holes in the door trim. 2. Screws securing the armrest to the door trim. Page 4583 Figure 3 Figure 4 Figure 5 Figure 6 1. Separate connector halves (see Figures 2 through 6). Page 7282 Voltage Drop Test TESTING FOR VOLTAGE DROP This test checks for voltage being lost along a wire, or through a connection or switch. 1. Connect the positive lead of a voltmeter to the end of the wire (or to one side of the connection or switch) which is closer to the Battery. 2. Connect the negative lead to the other end of the wire (or the other side of the connection or switch). 3. Operate the circuit. 4. The voltmeter will show the difference in voltage between the two points. Testing for Short with Test Light or Voltmeter TESTING FOR SHORT TO GROUND With a Test Light or Voltmeter 1. Remove the blown fuse and disconnect the load. 2. Connect a test light or voltmeter across the fuse terminals (be sure that the fuse is powered). 3. Beginning near the Fuse Block, wiggle the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching the test light or voltmeter. 4. When the test light glows, or the voltmeter registers, there is a short to ground in the wiring near that point.