MALFUNCTION INDICATOR LAMP. Oldsmobile Aurora 1995

SUBJECT: MALFUNCTION INDICATOR LAMP ("SERVICE ENGINE SOON" LIGHT) COMES ON IN RAPID AMBIENT TEMPERATURE CHANGE, DTC 121 WILL SET (REPLACE HVAC PROGRAMMER)

MODELS: 1995 OLDSMOBILE AURORA WITH 4.0L ENGINE (VIN C - RPO L47)

CONDITION:

SOME OWNERS MAY COMMENT THAT THE MALFUNCTION INDICATOR LAMP ("SERVICE ENGINE SOON" LIGHT) COMES ON DURING A RAPID AMBIENT TEMPERATURE CHANGE (FROM A MODERATE TO COLD AMBIENT TEMPERATURE). ALSO, DIAGNOSTIC TROUBLE CODE (DTC) 121, A/C HIGH SIDE TEMPERATURE SENSOR CIRCUIT, WILL SET. NO OTHER DTC'S WILL BE SET. IN CERTAIN AMBIENT TEMPERATURES, THE HVAC PROGRAMMER WILL SET A "FALSE" DTC 121.

CORRECTION:

FOLLOW THE DIAGNOSIS FOR DTC 121 IN SECTION 6E3-A OF THE SERVICE MANUAL TO ENSURE THAT A "LEGITIMATE" DTC 121 IS NOT SET. IF NO OTHER DTC'S ARE SET, REPLACE THE HVAC PROGRAMMER WITH P/N 16222233.

PARTS INFORMATION:

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER DESCRIPTION LABOR TIME =============== =========== ==========

D0780 PROGRAMMER, A/C - REPLACE USE PUBLISHED LABOR TIME

FIGURES: 00 ATTACHMENTS: 00

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.