CAMPAIGN:DIESEL ENGINES HIGH EMISSIONS

CONDITION GENERAL MOTORS HAS DETERMINED THAT CERTAIN EARLY BUILT 1984 "B", "D", "E" AND "G" SERIES EQUIPPED WITH A 4.3L V-6 OR 5.7L V-8 DIESEL ENGINE MAY HAVE BEEN BUILT INCORRECTLY AND, THEREFORE, MAY NOT COMPLY WITH EXHAUST EMISSION STANDARDS. VEHICLES INVOLVED MAY HAVE BEEN MANUFACTURED WITH ONE OR MORE OF THE FOLLOWING (4) FOUR CONDITIONS: A. "G" SERIES WITH V-8 (LF9) OR V-6 (LT6) DIESEL ENGINE, AND FEDERAL (NA5) EMISSIONS PACKAGE. THE WIRING HARNESS LEADS TO THE ALTITUDE ADVANCE DIODE WERE REVERSED. B. "G" SERIES WITH V-8 DIESEL (LF9) AND FEDERAL (NA5) OR HIGH ALTITUDE (NA6) PACKAGE. THE WIRING HARNESS COLD ADVANCE DIODE WAS REVERSED. C. "G", "B", "C", AND "E" SERIES MODEL, WITH V-8 (LF9) DIESEL AND THE HIGH ALTITUDE (NA6) PACKAGE. THE VACUUM HARNESS HOSES TO THE VACUUM REDUCER VALVE WERE REVERSED. D. "A" SERIES WITH A V-6 (LT7) DIESEL ENGINE AND THE HIGH ALTITUDE (NA6) PACKAGE, OR "B" AND "C" SERIES WITH A V-8 (LF9) DIESEL ENGINE AND THE HIGH ALTITUDE (NA6) PACKAGE. THE ALTITUDE ADVANCE DIODE WAS NOT REMOVED FROM THE WIRING HARNESS. VEHICLES INVOLVED CERTAIN 1984 MODELS WITH A V-6 OR V-8 DIESEL ENGINE BUILT FROM THE START OF PRODUCTION THROUGH THE FOLLOWING SERIAL NUMBERS. ASSEMBLY UP TO AND MODEL PLANT BEGINNING INCLUDING CONDITION A-V6 DIESEL LT6 W/NA5 OR V8 DIESEL LF9 W/NA5 "G" SERIES LANSING EM300001 EM331342 "G" SERIES ARLINGTON ER300001 ER311851 CONDITION B-V8 DIESEL LF9 W/NA5 OR NA6 "G" SERIES LANSING EM300001 EM331342 "G" SERIES ARLINGTON ER300001 ER311851 CONDITION C-V8 DIESEL LF9 W/NA6 "G" SERIES ARLINGTON ER300001 ER305617 "B" WAGON FAIRFAX EX300001 EX302745 "E" LINDEN EE300001 EE305261 "B" AND "C" LANSING EM700001 EM721271 CONDITION D-V6 DIESEL LT7 AND V8 DIESEL LF9 W/NA6 "A" SERIES DORAVILLE ED300001 ED325072 88/89 "B" AND "C" LANSING EM700001 EM721271

MORE THAN ONE CORRECTION MAY BE REQUIRED ON EACH VEHICLE INVOLVED. REFER TO THE PRINTOUTS SENT TO THE DEALERSHIP TO IDENTIFY WHICH CORRECTIONS MUST BE PERFORMED ON EACH VEHICLE LISTED. FOR EACH VEHICLE ON THE DEALER PRINTOUT SHEETS WILL BE LISTED AN A,B,C OR D OR A COMBINATION OF THESE LETTERS TO CORRESPOND TO CORRECTION A, B, C, OR D IN THIS CAMPAIGN BULLETIN. SERVICE PROCEDURE CORRECTION A REVERSE THE WIRE TERMINAL LEADS IN THE ENGINE HARNESS CONNECTOR TO THE ALTITUDE ADVANCE DIODE AS FOLLOWS: 1. OPEN HOOD. 2. REMOVE THE ALTITUDE ADVANCE DIODE LOCATED ON THE ENGINE WIRING HARNESS ABOVE THE MASTER CYLINDER. REFER TO FIGURE 1. 3. WITH A SMALL SCREWDRIVER, UNLOCK THE WIRE TERMINALS FROM THE ENGINE WIRING HARNESS CONNECTOR AND REMOVE THE TERMINALS FROM THE CONNECTOR. 4. REVERSE THE POSITION OF THE TWO TERMINALS AND REINSTALL INTO THE CONNECTOR. 5. REINSTALL THE DIODE ASSEMBLY ON THE ENGINE WIRING HARNESS. 6. IF THIS VEHICLE IS A V8 (LF9) DIESEL CORRECTION B MUST ALSO BE PERFORMED. 7. INSTALL A CAMPAIGN CORRECTION LABEL ON THE RADIATOR SUPPORT AND CLOSE HOOD. CORRECTION B REVERSE THE DIRECTION OF THE COLD ADVANCE DIODE IN THE ENGINE WIRING HARNESS. LOCATE THE COLD ADVANCE DIODE (SPLICED INTO THE ENGINE WIRING HARNESS) AS FOLLOWS: 1. OPEN HOOD AND LOCATE THE ALTITUDE ADVANCE DIODE LOCATED ABOVE THE MASTER CYLINDER. REFER TO FIGURE 1. 2. FOLLOW THE LIGHT GREEN/BLACK WIRES FROM THE ALTITUDE ADVANCE DIODE INTO THE WIRING HARNESS CONDUIT (APPROXIMATELY 14") TO THE TAPED SPLICED. DO NOT REMOVE TAPE FROM SPLICE. 3. AT THIS POINT YOU SHOULD SEE SILVER/GRAY TAPE WHICH COVERS THE COLD ADVANCE DIODE. THE DIODE HAS A DARK GREEN WIRE AND LIGHT GREEN WIRE WITH A BLACK TRACER LEADING TO IT. 4. CUT THE DARK GREEN AND LIGHT GREEN WIRES TO ABOUT 1" OF THE GREEN WIRE IS LEFT ON EACH SIDE OF THE COLD ADVANCE DIODE LEADS. 5. THE COLD ADVANCE DIODE SHOULD BE SOLDERED BACK INTO THE HARNESS WITH ITS LEADS REVERSED. THAT IS, THE LIGHT GREEN WIRE ON THE DIODE SHOULD BE SOLDERED TO THE DARK GREEN WIRING HARNESS LEAD AND THE DARK GREEN DIODE LEAD SHOULD BE SOLDERED TO THE LIGHT GREEN HARNESS LEAD. THIS PROCEDURE CAN ALSO BE PERFORMED WITH ELECTRICAL WIRE CRIMP ON SPLICES, IF AVAILABLE. 6. USING ELECTRICAL TAPE, TAPE OVER BOTH SOLDER OR CRIMP JOINTS TO INSULATE THEM. 7. CAREFULLY TUCK THE DIODE AND WIRES BACK INTO THE ENGINE WIRING HARNESS CONDUIT. 8. IF THIS VEHICLE HAS A HIGH ALTITUDE PACKAGE (NA6) CORRECTION C MUST ALSO BE PERFORMED. 9. INSTALL A CAMPAIGN CORRECTION LABEL ON THE RADIATOR SUPPORT AND CLOSE HOOD.. CORRECTION C REVERSE THE VACUUM HOSES AT THE VACUUM REDUCER VALVE. 1. OPEN HOOD. 2. LOCATE THE VACUUM REDUCER VALVE LOCATED TO THE RIGHT OF THE AIR INTAKE CROSSOVER. REFER TO FIGURE 2. 3. DISCONNECT THE VACUUM HOSE FROM THE PORT ON THE SINGLE PORT SIDE OF THE VALVE. 4. REMOVE THE VACUUM HOSE FROM THE CENTER PORT ON THE TWO PORT SIDE OF THE VACUUM REDUCER VALVE AND CONNECT IT TO THE PORT ON THE SINGLE PORT SIDE OF THE VALVE. 5. RECONNECT THE HOSE FROM STEP 3 TO THE CENTER PORT ON THE TWO PORT SIDE OF THE VALVE. 6. IF THIS VEHICLE IS AN 88 OR 98 CORRECTION D MUST ALSO BE PERFORMED 7. INSTALL A CAMPAIGN CORRECTION LABEL ON THE RADIATOR SUPPORT AND CLOSE THE HOOD. CORRECTION D REMOVE THE ALTITUDE ADVANCE DIODE. 1. OPEN HOOD. 2. LOCATE THE ALTITUDE ADVANCE DIODE ON THE ENGINE WIRING HARNESS. REFER TO FIGURE 3 FOR CUTLASS CIERA AND FIGURE 4 FOR 88 AND 98. 3. REMOVE THE ALTITUDE ADVANCE DIODE ASSEMBLY FROM THE WIRING HARNESS CONNECTOR AND DISCARD. 4. TAPE EMPTY CONNECTOR TO HARNESS ASSEMBLY. 5. INSTALL A CAMPAIGN CORRECTION LABEL ON THE RADIATOR SUPPORT AND CLOSE THE HOOD.

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.