CAMPAIGN: 4WD INDICATOR LIGHT WIRING (OSHAWA ASSY. PLANT)

NUMBER: 91-C-05 DATE: NOVEMBER, 1990 GROUP: 8B - CHASSIS ELECTRICAL

SUBJECT: 4WD INDICATOR LIGHT WIRING

MODELS: 1991 K 15-35 PICKUPS BUILT AT OSHAWA TRUCK ASSEMBLY CENTRE

*** SEE BOTTOM OF BULLETIN FOR INFORMATION CONCERNING OTHER AFFECTED *** DIVISIONS (CHEVROLET).

GENERAL MOTORS HAS DETERMINED THAT ON CERTAIN 1991 K 15-35 PICKUPS BUI AT THE OSHAWA TRUCK ASSEMBLY CENTRE THE FRONT AXLE INDICATOR LIGHT MAY NOT WORK AS INTENDED. AN ELECTRICAL FEEDBACK CONDITION MAY ALLOW THE LIGHT TO REMAIN ON WHEN THE TRANSFER CASE IS SHIFTED FROM 4WD TO 2WD. IF THE VEHICLE CONTINUES TO BE OPERATED IN 2WD, THIS FEEDBACK CONDITIO WILL FAIL THE FRONT AXLE ENGAGEMENT SWITCH CAUSING THE LIGHT TO GO OUT WHEN THE VEHICLE IS AGAIN PLACED INTO 4WD, THE LIGHT WILL NOT GO ON AN THE RWAL SYSTEM WILL REMAIN ENABLED (NORMALLY DISABLED IN 4WD). IF TH RWAL IS ACTIVATED WHILE IN 4WD, A DIAGNOSTIC CODE 5 WILL BE SET IN THE RWAL MODULE. THIS DISABLES THE RWAL FUNCTION AND CAUSES THE BRAKE WARNING LIGHT ON THE INSTRUMENT PANEL TO ILLUMINATE AND REMAIN ON.

TO CORRECT THIS CONDITION A NEW WIRING HARNESS AND FRONT AXLE ENGAGEME SWITCH WILL BE INSTALLED.

VEHICLES INVOLVED

INVOLVED ARE CERTAIN 1991 K 15-35 PICKUPS BUILT AT THE OSHAWA TRUCK ASSEMBLY CENTRE. GMC VIN'S ARE LISTED BELOW:

DEALER VIN DEALER VIN

48-53507 2GTEK19K9M1514529 48-10291 2GTEK19K3M1514560 48-06450 2GTFK24K3M1514530 48-30201 2GTEK19K6M1514567 48-53531 2GTEK19C6M1514531 48-30606 2GTEK19K9M1514577 48-50323 2GTEK19K6M1514536 48-44622 2GTEK19K2M1514579 48-56149 2GDFK29K2M1514538 48-30017 2GTEK19K1M1514587 48-06507 2GTEK14K3M1514548 48-06519 2GTEK19K4M1514597 48-06333 2GTEK19H0M1514553 48-42048 2GTEK19K6M1514617 48-47122 1GTEK19KXM1514555

OWNER NOTIFICATION

THERE WILL BE NO OWNER LETTER SENT OUT WITH THIS CAMPAIGN AS IT IS ANTICIPATED THE VEHICLES SHOULD STILL BE IN YOUR NEW VEHICLE INVENTORY AND SHOULD BE REPAIRED PRIOR TO RETAIL SALE. IF A UNIT HAS BEEN RETAILED, IN ORDER TO MAINTAIN CUSTOMER SATISFACTION, CONTACT THE OWNE IMMEDIATELY AND ARRANGE TO CORRECT THIS CONDITION ON HIS/HER VEHICLE.

SERVICE PROCEDURE

INSPECTION:

RAISE THE TRUCK ON A HOIST AND CHECK THE WHITE 4-WAY CONNECTOR AT THE FRONT AXLE FOR WIRE COLORS (FIGURE 1). IF THE WIRE IN CAVITY "A" IS BROWN, THE TRUCK HAS THE CORRECT WIRING HARNESS. IF CORRECT, PROCEED STEP 21 BELOW. IF THE WIRE IN CAVITY "A" IS BLUE, THE HARNESS AND THE FRONT AXLE SWITCH MUST BE CHANGED. PROCEED TO "REPAIR SECTION" BELOW. LOWER THE TRUCK.

REPAIR:

1. PREPARE THE TRUCK; DISCONNECT THE NEGATIVE BATTERY CABLE.

2. REMOVE THE CLAMP ON THE RIGHT FRAME RAIL THAT HOLDS THE BATTERY CABLE AND THE WIRING CONDUIT FROM THE FRONT AXLE SWITCH (FIGURE 1

3. FOR R05 (DUAL REAR WHEELS) ONLY, DISCONNECT THE RELAY CONNECTOR FROM INSIDE THE CONVENIENCE CENTER AT THE RIGHT SIDE OF THE TRUCK THE RELAY CONNECTOR WILL BE THE ONE TOWARD THE DRIVER'S SIDE (FIGURE 1).

4. DISCONNECT THE ENGINE WIRING HARNESS CONNECTOR BEHIND THE ENGINE. THIS IS A PURPLE WIRE BEHIND THE ENGINE, LOCATED APPROXIMATELY AT THE EDGE OF THE TRANSMISSION BELL HOUSING (FIGURE 2, VIEW A). TH CONNECTOR IS MORE ACCESSIBLE FROM UNDER THE HOOD, BUT IS VIEWED EASIER FROM UNDER THE TRUCK. THUS YOU MAY WANT TO RAISE THE TRUC BEFORE DISCONNECTING THIS CONNECTOR.

5. RAISE THE TRUCK ON A HOIST.

6. DISCONNECT THE WHITE 4-WAY CONNECTOR TO THE FRONT AXLE ENGAGEMENT SWITCH, AND DISCONNECT THE CONNECTOR TO THE ACTUATOR. THESE ARE LOCATED RIGHT NEXT TO EACH OTHER.

7. OPEN THE HARNESS CLIP THAT IS BOLTED TO THE TRANSMISSION BELL HOUSING JUST ABOVE THE STARTER HEAT SHIELD (FIGURE 2, VIEW A), AN OPEN THE HARNESS CLIP LOCATED ON THE TOP RIGHT OF THE TRANSFER CA (FIGURE 2).

8. DISCONNECT THE THREE CONNECTORS ON THE LEFT SIDE OF THE TRANSMISSION, ONE WHICH CONNECTS TO THE INDICATOR LAMP (ATTACHED THE FLOOR PAN), ONE WHICH CONNECTS TO THE FRONT SIDE OF THE TRANSFER CASE, AND ONE TO THE OUTPUT SPEED SENSOR (A BRASS COLORE PIECE ON THE SIDE OF THE TRANSMISSION) (FIGURE 2). FOR TRUCKS WI MT1 (4L80E) TRANSMISSIONS, THERE WILL BE AN ADDITIONAL TWO PIN CONNECTOR EXTENSION FROM THE OUTPUT SPEED SENSOR THAT SHOULD BE DISCONNECTED.

9. DISCONNECT THE HARNESS FROM THE BACK OF THE TRANSFER CASE AT THE VEHICLE SPEED SENSOR. FOR TRUCKS WITH R05 (DUAL REAR WHEELS) THE WILL BE AN ADDITIONAL CONNECTOR WITH A LARGE RED WIRE TO BE DISCONNECTED (FIGURE 2, VIEW B).

10. FABRICATE A PULL WIRE ABOUT FOUR TO FIVE FEET LONG, AND ATTACH IT TO THE FRONT AXLE END OF THE HARNESS.

11. PULL THE HARNESS THROUGH THE STARTER HEAT SHIELD FROM THE TRANSMISSION SIDE OF THE TRUCK, LEAVING THE PULL WIRE RUNNING THROUGH THE HEAT SHIELD.

12. CONNECT THE NEW HARNESS TO THE PULL WIRE ON THE FRONT AXLE CONNECTOR SIDE OF THE HARNESS AND TAPE OVER THE TWO CONNECTORS TO ALLOW THEM TO PASS THROUGH THE HEAT SHIELD EASILY.

13. PULL THE NEW HARNESS THROUGH THE HEAT SHIELD TOWARD THE FRONT AXL SIDE.

14. REMOVE AND REPLACE THE FRONT AXLE ENGAGEMENT SWITCH.

15. RECONNECT THE HARNESS TO THE FRONT AXLE ENGAGEMENT SWITCH AND ACTUATOR, AND TIE STRAP THE HARNESS TO THE STARTER WIRES AT THE BOTTOM OF THE STARTER HEAT SHIELD.

IMPORTANT: THE HARNESS MUST BE LOOPED UNDER THE BATTERY CABLE HARNESS ON THE FRAME RAIL TO PREVENT THE HARNESS FROM TOUCHING THE EXHAUST MANIFOLD (FIGURE 1).

16. CONNECT THE CONNECTORS TO THE LEFT SIDE OF THE TRANSMISSION AND T BACK OF THE TRANSFER CASE, AND RECLIP THE HARNESS TO THE CLIP AT THE TOP RIGHT OF THE TRANSFER CASE AND THE CLIP BOLTED TO THE TRANSMISSION BELL HOUSING.

17. FOR TRUCKS WITH R05 (DUAL REAR WHEELS) ATTACH THE PULL WIRE TO TH RELAY CONNECTOR, AND FEED THE PULL WIRE UP THROUGH THE TRUCK TO ASSIST IN RETRIEVING THIS CONNECTOR.

18. LOWER THE TRUCK, AND RECONNECT THE ENGINE WIRING HARNESS CONNECTO (THE PURPLE WIRE) AND THE RELAY CONNECTOR IN THE CONVENIENCE CENTER.

19. REFASTEN THE CLAMP ON THE RIGHT FRAME RAIL, KEEPING THE HARNESS ROUTED UNDER THE BATTERY CABLE AND FREE OF THE EXHAUST MANIFOLD.

20. RECONNECT THE BATTERY AND ROAD TEST TO VERIFY THE PROPER OPERATIO OF THE 4-WHEEL INDICATOR LAMP.

21. INSTALL "CAMPAIGN IDENTIFICATION LABEL".

PARTS INFORMATION

PARTS REQUIRED TO COMPLETE THIS CAMPAIGN WILL BE SHIPPED TO INVOLVED DEALERS BY GMC TRUCK ON A NO CHARGE BASIS VIA NEXT DAY DELIVERY. ANY QUESTIONS PERTAINING TO PARTS SHORTAGES, ETC. SHOULD BE DIRECTED TO ADISTRA CORPORATION (313) 455-9072.

DO NOT ORDER FROM GENERAL MOTORS SERVICE PARTS OPERATION (GMSPO).

PART NUMBER DESCRIPTION QUANTITY

12088262 WIRING HARNESS 1

15552842 FRONT AXLE ENGAGEMENT SWITCH 1

WARRANTY INFORMATION

DEALERS SHOULD SUBMIT A WARRANTY CLAIM ON EACH VEHICLE COMPLETED UNDER THIS CAMPAIGN.

LABOR OPERATION *TIME **PARTS TROUB NUMBER DESCRIPTION ALLOWANCE ALLOWANCE CODE

V6490 INSPECT - CORRECT .2 HR. 96 WIRING HARNESS ALREADY INSTALLED. NO FURTHER ACTION REQUIRED.

V6491 INSPECT AND INSTALL .7 HR. $26.96 96 NEW WIRING HARNESS AND FRONT AXLE ENGAGEMENT SWITCH.

ADD: IF EQUIPPED WITH .2 HR. DUAL REAR WHEELS (R05)

* FOR DEALER TO RECEIVE ADMINISTRATIVE TIME ALLOWANCE ASSOCIATED WI THIS CAMPAIGN, ADD 0.1 HOUR TO THE LABOR OPERATION TIME ALLOWANCE

** THE $26.96 AMOUNT IDENTIFIED IN THE "PARTS ALLOWANCE" COLUMN ABOV REPRESENTS 30% OF DEALER NET FOR PARTS THAT WERE FURNISHED BY GMC TRUCK DIVISION. THIS AMOUNT IS TO BE PLACED IN THE NET ITEM AMOU COLUMN OF THE CLAIM AND USE TYPE CODE "M".

CAMPAIGN IDENTIFICATION LABEL

EACH VEHICLE CORRECTED IN ACCORDANCE WITH THE INSTRUCTIONS OUTLINED IN THIS PRODUCT CAMPAIGN BULLETIN WILL REQUIRE A "CAMPAIGN IDENTIFICATION LABEL." EACH LABEL PROVIDES A SPACE TO INCLUDE THE CAMPAIGN NUMBER AN FIVE (5) DIGIT DEALER CODE OF THE DEALER PERFORMING THE CAMPAIGN SERVICE. THIS INFORMATION MAY BE INSERTED WITH A TYPEWRITER OR BALL POINT PEN.

EACH "CAMPAIGN IDENTIFICATION LABEL" IS TO BE LOCATED ON THE RADIATOR CORE SUPPORT IN AN AREA WHICH WILL BE VISIBLE WHEN THE VEHICLE IS BROUGHT IN FOR PERIODIC SERVICING BY THE OWNER.

APPLY "CAMPAIGN IDENTIFICATION LABEL" ONLY ON A CLEAN, DRY SURFACE.

ADMINISTRATIVE PROCEDURE

PROCEDURES COVERING THIS CAMPAIGN ARE OUTLINED IN SECTION V OF YOUR DEALERSHIP'S "GM TRUCK CLAIMS PROCESSING MANUAL" #P8919.

*** INFORMATION SPECIFIC FOR CHEVROLET ONLY

VEHICLES INVOLVED

INVOLVED ARE CERTAIN 1991 CHEVROLET K 1500-3500 SERIES PICKUP TRUCKS BUILT AT THE OSHAWA ASSEMBLY CENTRE WITH THE FOLLOWING VIN BREAKPOINTS:

PLANT YEAR MODEL PLANT CODE FROM THROUGH 1991 K-TRUCK OSHAWA '1' M1142020 M1142448

PARTS INFORMATION

PARTS REQUIRED TO COMPLETE THIS CAMPAIGN WILL BE SHIPPED DIRECTLY TO INVOLVED DEALERS BY CHEVROLET MOTOR DIVISION ON A NO CHARGE BASIS VIA NEXT DAY DELIVERY. ANY QUESTIONS PERTAINING TO PARTS SHORTAGES, ETC. SHOULD BE DIRECTED TO THE CHEVROLET DEALER ASSISTANCE CENTER

DO NOT ORDER FROM GENERAL MOTORS SERVICE PARTS OPERATION (GMSPO)

QUANTITY/ PART NUMBER DESCRIPTION VEHICLE APPLICATION 12088249 WIRING HARNESS 1 K 3500 (1 TON) AND MT1 (4L80E)

12088250 WIRING HARNESS 1 K 2500 (3/4 TON) AND MT1 (4L80E)

12088262 WIRING HARNESS 1 K 1500-2500 (1/2 AND 3/4 TON) AND MD8, MG5, MT8 OR M20

12088263 WIRING HARNESS 1 K 3500 (1 TON) AND MT8 OR M20

15552842 FRONT AXLE 1 K 1500-2500 (1/2 AND ENGAGEMENT SWITCH 3/4 TON)

15638264 FRONT AXLE 1 K 3500 (1 TON) ENGAGEMENT SWITCH

CLAIM INFORMATION FOR CHEVROLET ONLY

SUBMIT A PRODUCT CAMPAIGN CLAIM WITH THE INFORMATION INDICATED BELOW:

* ** FAILED PARTS CC LAB LAB OTH NET REPAIR PERFORMED PC PART NO. ALLOW FC OP HRS HRS AMT INSPECT - CORRECT WIRING HARNESS ALREADY INSTALLED - - - SK V6490 0.2 0.1 $0.00 NO FURTHER ACTION REQUIRED 00

INSPECT AND INSTALL NEW WIRING HARNESS AND FRONT - - - SK V6491 0.7 0.1 $27.05 AXLE ENGAGEMENT SWITCH 00

* CAMPAIGN ADMINISTRATION ALLOWANCE. ADD 0.2 HOURS FOR VEHICLES EQUIPPED WITH DUAL REAR WHEELS (RPO RO5) AS NEEDED AFTER OBTAINING WHOLESALE AUTHORIZATION 'E'.

** THE $27.05 IDENTIFIED IN THE 'NET AMOUNT' COULMN REPRESENTS 30% OF DEALER NET FOR PARTS FURNISHED BY CHEVROLET MOTOR DIVISION AND USED IN CONJUNCTION WITH LABOR OPERATION V6491

DEALERS WILL AUTOMATICALLY RECEIVE THE CORRECT LABOR BASED ON THE LABOR OPERATION PERFORMED. REFER TO THE CHEVROLET CLAIMS PROCESSING MANUAL FOR DETAILS ON PRODUCT CAMPAIGN CLAIM SUBMISSION.

COPYRIGHT 1990 CHEVROLET MOTOR DIVISION GENERAL MOTORS CORPORATION ALL RIGHTS RESERVED.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.