NO START, BATTERY FULLY DISCHARGED. Chevrolet Lumina 1995

SUBJECT: NO START, BATTERY FULLY DISCHARGED (REPLACE PRIMARY COOLING FAN RELAY--INSTALL NEW PROM)

MODELS: 1995 CHEVROLET LUMINA, MONTE CARLO 1995 OLDSMOBILE CUTLASS SUPREME 1995 PONTIAC GRAND PRIX WITH 3.4L TWIN DOHC ENGINE (VIN X - RPO LQ1)

CONDITION:

SOME OWNERS MAY EXPERIENCE A NO START CONDITION DUE TO A DISCHARGED BATTERY.

CAUSE:

THE DISCHARGED BATTERY CONDITION IS DUE TO THE PRIMARY COOLING RELAY CONTACTS WELDING. WHEN THIS HAPPENS, THE COOLING FAN CONTINUES TO RUN UNTIL THE BATTERY IS FULLY DISCHARGED. THE CONTACTS WELD WHEN THE ENGINE IS SHUT OFF WITH THE A/C COMPRESSOR CLUTCH BEING ENGAGED BEFORE THE PCM ACTIVATES THE PRIMARY FAN RELAY. THE A/C CLUTCH DRIVES ALL IGNITION 1 DEVICES TO A NEGATIVE VOLTAGE. THIS NEGATIVE VOLTAGE CAUSES THE PCM TO ENERGIZE THE COOLING FAN RELAY. IN A VERY SHORT PERIOD OF TIME, THERE IS A HIGH IN-RUSH OF CURRENT TO THE COOLING FAN. THE WELDING OF THE RELAY CONTACTS OCCURS WHEN THE RELAY DEACTIVATES WHEN A VERY HIGH IN-RUSH OF CURRENT IS PRESENT.

CORRECTION:

AFTER FOLLOWING STANDARD PROCEDURES FOR DIAGNOSING A FULLY DISCHARGED BATTERY AND IT IS DETERMINED THAT THE PRIMARY COOLING FAN RELAY CONTACTS ARE WELDED, IT WILL BE NECESSARY TO REPLACE BOTH THE RELAY AND INSTALL A NEW PROM. THE NEW PROM CHANGES THE CALIBRATIBLE VALUE FOR MINIMUM A/C COMPRESSOR HEAD PRESSURE FROM APPROXIMATELY 190 PSI TO 42 PSI. THIS INSURES THAT THE COOLING FAN WILL BE OPERATIONAL DURING ANY PERIOD WHEN THE A/C SYSTEM IS IN OPERATION.

PARTS INFORMATION

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

PART NAME PART NUMBER QTY B/C CODE SCAN ID

RELAY 12088576 1 -- --

MEMCAL 16229657 1 BSBH 9644

WARRANTY INFORMATION FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION: J6364 PROM, PCM-REPLACE LABOR TIME: 0.7 HRS

LABOR OPERATION: N2850 RELAY, PRIMARY COOLING FAN-REPLACE LABOR TIME: USE PUBLISHED LABOR OPERATION TIME.

FIGURES: 0 ATTACHMENTS: 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.