For 1990-2009 cars

# HEADLAMPS WILL NOT TURN OFF - INFORMATIONAL

REVISION: 12/09/94

THIS BULLETIN IS BEING REVISED TO ADD EXPANDED CONDITION INFORMATION AND CORRECTIVE ACTION.

PREVIOUS DIVISIONAL DCS NUMBERS WERE: BUICK DCS95-09 PONTIAC DCS-TS50 ----------------------------------------------------------------------

#### SUBJECT: HEADLAMPS WILL NOT TURN OFF ON VEHICLES WITH TWILIGHT SENTINEL (T82) OR DAYTIME RUNNING LAMPS (T61), (OPEN CIRCUIT 120)

#### MODELS: 1995 BUICK LESABRE, PARK AVENUE 1995 OLDSMOBILE EIGHTY EIGHT, NINETY EIGHT 1995 PONTIAC BONNEVILLE

#### VIN BREAKPOINTS:

LESABRE - 458120 PARK AVENUE/ULTRA - 624194 EIGHTY EIGHT - 817950 NINETY EIGHT - 310745 BONNEVILLE - 237691

#### NOTE: THIS BULLETIN DOES NOT ADDRESS THE CONDITION OF THE HEADLAMPS REMAINING ON WITH THE TWILIGHT SENTINEL ENABLED, THE IGNITION SWITCH TURNED "OFF" AND THE VEHICLE OUT OF "PARK". THIS IS COVERED IN CORPORATE BULLETIN #438133.

THIS BULLETIN ALSO SHOULD NOT BE CONFUSED WITH THE CONDITION(S) ADDRESSED BY PRODUCT CAMPAIGNS 95-C-04 OR 95-C-07 AND OUTLINED IN UPCOMING CANADIAN CAMPAIGN #4D48. HOWEVER, THE PROCEDURES IN THIS BULLETIN SHOULD BE PERFORMED IN ADDITION TO REPLACING THE LIGHTING CONTROL MODULES AFFECTED BY THE PRODUCT CAMPAIGNS TO INSURE THAT THE CONCERN HAS BEEN CORRECTED.

#### CONDITION:

SOME OWNERS MAY COMMENT THAT THE HEADLAMPS WILL NOT TURN OFF ON VEHICLES EQUIPPED WITH TWILIGHT SENTINEL (T82) OR DAYTIME RUNNING LAMPS (T61).

#### CAUSE:

WHEN THE IGNITION SWITCH IS CYCLED OFF, THE FUEL PUMP PROVIDES A TRANSIENT VOLTAGE BETWEEN THE FUEL PUMP AND THE LIGHTING CONTROL MODULE. THIS MAY CAUSE THE HEADLAMPS TO REMAIN ON.

#### CORRECTION:

REFERENCE PAGE 8A-20-10 IN THE APPROPRIATE SERVICE MANUAL FOR SCHEMATIC AND ATTACHED ILLUSTRATION IN THIS BULLETIN. THE FOLLOWING STEPS SHOULD BE PERFORMED TO INTERRUPT THE PATH FOR THE TRANSIENT BETWEEN THE FUEL PUMP AND THE LIGHTING CONTROL MODULE.

1. DISCONNECT NEGATIVE BATTERY CABLE.

2. LOCATE CIRCUIT 120, THE .80MM(2) GRAY WIRE LOCATED IN CAVITY A5 OF CONNECTOR C260. REFERENCE PAGES 8A-202-8 AND 9 IN THE APPROPRIATE SERVICE MANUAL.

3. FOLLOW CIRCUIT 120 WIRE BACK APPROXIMATELY 4 INCHES UNDER CONDUIT ON THE C260 BRANCH IN THE ENGINE COMPARTMENT.

4. CUT CIRCUIT 120 WIRE APPROXIMATELY 4 INCHES BACK UNDER THE CONDUIT.

5. MAKE SURE THAT NONE OF THE CORE IS EXPOSED. BOTH SIDES OF THE CIRCUIT 120 WIRE WILL HAVE B+ ON IT. FULLY INSULATE BOTH ENDS OF CIRCUIT 120 WIRE TO PREVENT ANY POSSIBILITY OF EITHER END SHORTING.

6. WRAP EACH END OF CIRCUIT 120 WIRE WITH SPLICE TAPE. THEN WRAP INTO HARNESS MAIN WITH ELECTRICAL TAPE.

7. SECURE THE CUT AND INSULATED LEADS IN THE WIRING BUNDLE.

8. REPLACE ANY HARNESS COVERING THAT WAS REMOVED.

9. RECONNECT BATTERY AND CHECK OPERATION OF HEADLAMPS.

#### WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: T2590 LABOR TIME: 0.3 HR.

FIGURES: 1

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.

COPYRIGHT 1994 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.