For 1990-2009 cars

# FAULTY ABS MAIN RELAY OR ABS PUMP RELAY CAUSING ABS DTC

REVISION: 04/27/94

THIS BULLETIN IS BEING REVISED TO INCLUDE BULLETIN AND SERVICE MANUAL REFERENCES WHEN DIAGNOSING DTC 45 OR 61 IN THE "CORRECTION" SECTION. ----------------------------------------------------------------------

#### SUBJECT: FAULTY ABS MAIN RELAY OR ABS PUMP RELAY CAUSING ABS DIAGNOSTIC TROUBLE CODES (DTC'S) 45 OR 61 (DIAGNOSE/ SERVICE PROCEDURE)

#### MODELS: 1991-94 BUICK LESABRE AND PARK AVENUE 1991-94 OLDSMOBILE EIGHTY EIGHT AND NINETY EIGHT 1991-94 PONTIAC BONNEVILLE

#### CONDITION:

SOME OWNERS MAY COMMENT THAT THE "ABS" AND, IF EQUIPPED, "TRACTION OFF" INDICATOR LAMPS ARE ON DUE TO THE PRESENCE OF ABS DIAGNOSTIC TROUBLE CODES (DTC'S) 45 AND 61.

#### CAUSE:

EITHER OR BOTH OF THE ABOVE DTC'S COULD SET DUE TO A HIGH CONTACT RESISTANCE CONDITION WITH THE ABS MAIN RELAY OR THE ABS PUMP RELAY.

#### CORRECTION:

REFER TO BULLETIN #335015 WHEN DIAGNOSING DTC 45 OR BULLETIN #315006R (PREVIOUS DIVISIONAL NUMBERS WERE: T-93-97 - CADILLAC; 93-5-124 - CANADA; 93-T-71 - OLDSMOBILE; 93-5-14 - PONTIAC) WHEN DIAGNOSING DTC 61 FOR 1991-1993 MODEL YEAR VEHICLES. WHEN DIAGNOSING DTC 61 ON 1994 MODEL YEAR VEHICLES, USE THE APPROPRIATE SERVICE MANUAL, SECTION 5E2, DIAGNOSTIC PROCEDURE.

IF THE DIAGNOSTIC PROCEDURE INDICATES THAT THE EBCM/EBTCM OR THE PRESSURE MODULATOR VALVE (PMV) SHOULD BE REPLACED, THE FOLLOWING RELAY TEST SHOULD BE PERFORMED FIRST:

1. IGNITION TO "OFF" POSITION.

2. REMOVE APPROPRIATE RELAY DETERMINED BY DTC AND MODEL YEAR AS FOLLOWS:

MODEL YEAR ABS/DTC RELAY ========== ======= =====

1991-94 45 ABS MAIN 1991 61 ABS PUMP 1992-94 61 ABS MAIN OR PUMP

3. USING TERMINAL REPAIR TOOLS FROM J 38125-A, REMOVE RELAY HARNESS CONNECTOR TERMINALS 1 AND 4 (1991 - 1993) OR 30 AND 87 (1994) FROM RELAY HARNESS CONNECTOR. DO NOT ATTEMPT TO PERFORM THIS TEST WITHOUT REMOVING THESE TERMINALS OR AN IMPROPER RESISTANCE READING WILL BE MADE.

4. REINSTALL RELAY.

5. DISCONNECT EBCM/EBTCM.

6. INSTALL J 38716 ABS BREAKOUT BOX.

7. USING J 35616-A CONNECTOR TEST ADAPTOR KIT, CONNECT TEST LEADS FROM J 39200 DIGITAL MULTIMETER TO RELAY THROUGH OPEN CAVITIES IN HARNESS CONNECTOR.

8. SET J 39200 TO OHM'S SCALE.

9. IGNITION TO THE RUN POSITION.

10. USING A FUSED JUMPER, JUMP BETWEEN BREAKOUT BOX TERMINALS 1 AND 34 FOR THE ABS MAIN RELAY OR 1 AND 15 FOR THE ABS PUMP RELAY. ENERGIZE AND DE-ENERGIZE THE RELAY AT LEAST TEN TIMES WHILE MONITORING RELAY CONTACT RESISTANCE. IF RELAY CONTACT RESISTANCE EXCEEDS 1 OHM AT ANY TIME, THE RELAY MUST BE REPLACED.

11. IF RELAY TESTS OKAY, RESUME ORIGINAL DIAGNOSTIC PROCEDURE. IF RELAY IS REPLACED, PERFORM APPROPRIATE MODEL YEAR ABS OR ABS/TCS FUNCTIONAL TEST.

#### WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: H2490 (FOR ABS MAIN RELAY REPLACEMENT) USE PUBLISHED LABOR OPERATION TIME.

H2475 (FOR ABS PUMP RELAY REPLACEMENT) USE PUBLISHED LABOR OPERATION TIME.

FIGURES: 0

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.