GM Service Manual Online
For 1990-2009 cars only

ABS OR TCS INDICATOR LAMPS ON DUE TO DTC'S 21/22/23

SUBJECT: ABS, AND IF EQUIPPED, TCS INDICATOR LAMPS COME ON DUE TO PRESENCE OF DIAGNOSTIC TROUBLE CODE(S) 21, 22 OR 23 OR FALSE ABS OR ABS/TCS CYCLING (REROUTE HARNESS)

MODELS: 1992-94 BUICK PARK AVENUE 1992-94 OLDSMOBILE NINETY EIGHT 1992-94 PONTIAC BONNEVILLE WITH 3.8L SUPERCHARGED ENGINE (VIN 1 - RPO L67)

CONDITION:

SOME OWNERS MAY COMMENT ON FALSE ABS, OR IF EQUIPPED, TCS CYCLING OR "ABS" OR "TRACTION OFF" INDICATOR LAMPS COME ON WITH BOTH SYSTEMS DISABLED DUE TO THE PRESENCE OF RIGHT SIDE WHEEL SPEED SENSOR DIAGNOSTIC TROUBLE CODE(S) (DTC'S) 21, 22 OR 23 PRESENT.

CAUSE:

TOO MUCH LENGTH TO THE WIRING HARNESS THAT PLUGS INTO THE RIGHT SIDE WHEEL SPEED SENSOR JUMPER HARNESS CAUSES THE HARNESS TO MAKE CONTACT WITH THE POWER STEERING PULLEY WHICH EVENTUALLY WEARS THROUGH THE HARNESS INSULATION.

IN SOME CASES, THE EBCM/EBTCM INTERPRETS THE POWER STEERING PULLEY CONTACT AS A WHEEL SPEED SIGNAL WHICH COULD CAUSE THE FALSE ABS OR TCS CYCLING. ALSO, IN SOME CASES, DIFFICULTY ENTERING THE DIAGNOSTIC MODE COULD BE ENCOUNTERED WITH THE VEHICLE IDLING DUE TO THIS CONDITION SINCE THE EBCM/EBTCM WILL NOT ALLOW ENTRY INTO DIAGNOSTICS IF IT CALCULATES ANY WHEEL SPEED ABOVE 7MPH (10KM/H).

CORRECTION:

REPAIR THE WIRING AS SPECIFIED IN SECTION 8A-5 OF THE APPROPRIATE SERVICE MANUAL AND REROUTE THE HARNESS USING THE FOLLOWING PROCEDURE:

1. UNPLUG THE RIGHT FRONT WHEEL SPEED SENSOR JUMPER HARNESS FROM THE RIGHT SIDE RAIL HARNESS CONNECTOR.

2. REROUTE THE RIGHT SIDE RAIL HARNESS CONNECTOR BEHIND THE RIGHT SIDE RAIL HARNESS (FIGURE 1).

3. CONNECT RIGHT FRONT WHEEL SPEED SENSOR JUMPER HARNESS TO THE RIGHT SIDE RAIL HARNESS CONNECTOR.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: N6035 USE PUBLISHED LABOR OPERATION TIME.

FIGURES: 1


Object Number: 84087  Size: FS

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.

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