For 1990-2009 cars

# CAMPAIGN:BRAKE VAC PUMP/LOW INDICATOR LAMP CIRCUIT MISSING

CONDITION GENERAL MOTORS HAS DETERMINED THAT SOME (309) 1985 "X" SERIES WERE ASSEMBLED WITHOUT A BRAKE VACUUM PUMP WIRING CIRCUIT AND 40 WITHOUT A LOW VACUUM INDICATOR LAMP CIRCUIT. THIS RESULTS IN AN INOPERATIVE BRAKE VACUUM PUMP AND/OR INOPERATIVE LOW VACUUM INDICATOR LAMP. VEHICLES INVOLVED CERTAIN 1985 "X" SERIES ASSEMBLED AT THE WILLOW RUN PLANT EQUIPPED WITH 2.8L V6 MFI (LB6 - ENGINE VIN CODE W). CHECK THE C.R.I.S. SYSTEM TO DETERMINE IF A SPECIFIC VEHICLE IS INVOLVED IN THIS CAMPAIGN. PART INFORMATION ONE (1) "LAMP CIRCUIT KIT" WILL BE FURNISHED "NO CHARGE" FOR EACH VEHICLE ON YOUR LISTING. IF A VEHICLE ALSO REQUIRES INSTALLATION OF THE "PUMP CIRCUIT KIT" (THE WORD "PUMP" LISTED TO THE RIGHT OF THE "CAMP ID" ON THE LISTING), A "PUMP KIT" WILL BE FURNISHED FOR THIS VEHICLE . THE "LAMP CIRCUIT KIT" CONTAINS: ONE (1) - JUMPER WIRE (TAN WITH WHITE STRIPE) APPROXIMATELY 19" LONG. ONE (1) - SPLICE CLIP ONE (1) CAMPAIGN IDENTIFICATION LABEL THE "PUMP CIRCUIT KIT" CONTAINS: ONE (1) JUMPER HARNESS ASSEMBLY (TWO (2) BROWN WIRES WITH WHITE STRIPE ASSEMBLED IN CONNECTOR) ONE (1) SINGLE WIRE CONNECTOR TECHNICAL PROCEDURE INSTALLATION OF "LAMP CIRCUIT KIT" (ALL VEHICLES INVOLVED) AND "PUMP CIRCUIT" KIT (CERTAIN INVOLVED VEHICLES). 1. OPEN VEHICLE HOOD AND COVER FENDERS. 2. DISCONNECT NEGATIVE CABLE FROM BATTERY. 3. LOOSEN BOLT THAT RETAINS ENGINE COMPARTMENT CONNECTOR ASSEMBLY TO FRONT OF DASH, AND UNPLUG ENGINE HARNESS PART OF CONNECTOR FROM I.P. HARNESS CONNECTOR. REMOVE I.P. HARNESS CONNECTOR FROM ITS MOUNTING BRACKET. REFER TO FIGURE 1. 4. REMOVE THE TERMINAL SECONDARY LOCK FROM I.P. CONNECTOR, AS SHOWN IN FIGURE 2. 5. REMOVE THE TAPE AND PLASTIC CONDUIT FROM THE MAIN I.P. HARNESS BACK TO A POINT WHERE THE BRAKE PRESSURE SWITCH CONNECTOR BRANCH (TO MASTER CYLINDER) LEAVES THE MAIN HARNESS. REFER TO FIGURE 3. 6. REMOVE THE TAPE AND CONDUIT FROM THE PRESSURE SWITCH BRANCH OF THE WIRING. 7. CUT THE TAN WIRE WITH WHITE STRIPE AT A PLACE APPROXIMATELY 7 INCHES FROM THE END OF THE PRESSURE SWITCH CONNECTOR. REFER TO FIGURE 3. STRIP BOTH ENDS OF THIS CUT WIRE. 8. USING FURNISHED SPLICE CLIP, SPLICE THE FURNISHED JUMPER WIRE LEAD TO THE TWO ENDS OF THE CUT WIRE. USE ROSIN CORE SOLDER AND SOLDER THIS CONNECTION. REFER TO FIGURE 4, VIEW A. 9. INSULATE THE SOLDERED CONNECTION WITH ELECTRICAL TAPE. 10. PLUG THE TERMINAL END OF THE JUMPER WIRE INTO CAVITY A-1 OF THE I.P. HARNESS CONNECTOR. REFER TO FIGURE 5 AND FIGURE 6. 11. REPLACE THE CONDUIT OVER THE PRESSURE SWITCH BRANCH AND MAIN I.P. HARNESS, INCLUDING THE NEW INSTALLED JUMPER WIRE. TAPE ALL WIRES EXPOSED BY THE REMOVAL OF THE TAPE IN STEPS 5 AND 6. 12. DETERMINE IF "PUMP CIRCUIT KIT" IS TO BE INSTALLED IN VEHICLE. REFER TO "VEHICLES INVOLVED" AND "PARTS INFORMATION" SECTION OF THIS BULLETIN. A. IF "PUMP CIRCUIT" KIT IS NOT TO BE INSTALLED, STEPS 13 THROUGH 16 ARE NOT REQUIRED, PROCEED TO STEP 17. B. IF PUMP CIRCUIT KIT IS TO BE INSTALLED, PROCEED WITH ALL OF THE FOLLOWING STEPS OF THIS PROCEDURE. 13. REMOVE THE TERMINAL SECONDARY LOCK FROM OTHER SIDE I.P. HARNESS CONNECTOR. REFER TO FIGURE 2. 14. REMOVE THE WIRE TERMINAL FROM CAVITY J6 OF CONNECTOR. REFER TO FIGURE 7. RAISE TERMINAL LOCK TANG TO ORIGINAL POSITION. PLUG THE FURNISHED SINGLE CONNECTOR ONTO THIS REMOVED TERMINAL AND LATCH THE CONNECTOR LOCK. REFER TO FIGURE 8. PLUG THIS CONNECTOR INTO CONNECTOR OF FURNISHED JUMPER HARNESS FROM PUMP KIT. 15. PLUG THE LARGER TERMINAL ON JUMPER HARNESS INTO CAVITY J6 AND THE OTHER TERMINAL TO CAVITY C3 OF INSTRUMENT PANEL CONNECTOR. REFER TO FIGURE 9 AND 10. 16. TAPE THE JUMPER HARNESS CONNECTOR AND WIRES TO THE I.P. HARNESS SO THAT THEY ARE COVERED AND FREE FROM POSSIBLE PINCH. 17. REINSTALL CONNECTOR SECONDARY LOCK(S). 18. INSTALL THE I.P. CONNECTOR BACK INTO ITS MOUNTING BRACKET, AND PLUG ENGINE HARNESS AND I.P. HARNESS CONNECTOR TOGETHER. 19. INSTALL CONNECTOR ASSEMBLY ON THE DASH, TORQUING BOLT TO 7 N.M (5 LBS. FT.). 20. CONNECT THE NEGATIVE CABLE TO THE BATTERY. 21. CHECK THE VACUUM PUMP LOW VACUUM INDICATOR WARNING LIGHT OPERATION AS FOLLOWS: A. REMOVE POWER BRAKE CHECK VALVE FROM BOOSTER. B. WITH PARK BRAKE RELEASED, TURN IGNITION TO "ON" OR "RUN" POSITION. DO NOT START ENGINE. - VACUUM PUMP SHOULD BE RUNNING. - BRAKE INDICATOR LIGHT ON INSTRUMENT PANEL CLUSTER SHOULD COME ON IN 15-45 SECONDS. C. AFTER LIGHT COMES ON, REINSTALL BRAKE BOOSTER CHECK VALVE AND START ENGINE AND RUN AT IDLE. BRAKE LIGHT SHOULD GO "OUT" IN LESS THAN TEN SECONDS AND VACUUM PUMP SHOULD STOP OPERATING. 22. IF VACUUM PUMP AND BRAKE INDICATOR LIGHT DID NOT OPERATE AS DESCRIBED IN STEP 21, LOCATE AND CHECK SYSTEM PROBLEM.

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.