HVAC DISPLAY ERRORS; LEFT TO RT. TEMP. DIFFERENCES. Buick Riviera 1995

REVISION: 11/30/94

THIS BULLETIN IS BEING REVISED FOR A WORD CORRECTION IN STEP #5. THE WORD "RELAY" IN THE PREVIOUS BULLETIN HAS NOW BEEN CHANGED TO "DELAY".

PLEASE DISCARD BULLETIN 431109 (GROUP REFERENCE 1 - HVAC).

SUBJECT: HVAC DISPLAY ERRORS; LEFT TO RIGHT TEMPERATURE DIFFERENCES; AND/OR BLOWER OPERATION CONCERNS (REPLACE HVAC PROGRAMMER)

MODELS: 1995 BUICK RIVIERA 1995 OLDSMOBILE AURORA

VIN BREAKPOINTS:

BUICK: S4700000 - S4712646 OLDSMOBILE: S4100000 - S4113711

CONDITION:

SOME OWNERS MAY COMMENT ON ONE OR MORE OF THE FOLLOWING CONDITIONS:

1. OUTSIDE AIR TEMPERATURE (OAT) DISPLAY IS NOT CORRECT ON KEY-UP.

2. AUTO BLOWER WILL NOT TURN ON WHEN COOLANT TEMPERATURE DOES NOT EXCEED 108 DEGREES FAHRENHEIT (42 DEGREES CELSIUS). THIS CONDITION IS ONLY POSSIBLE IF THE COOLANT TEMPERATURE THAT THE HVAC SYSTEM RECEIVES OVER UART (I.E. CKT 800) NEVER EXCEEDS 108 DEGREES FAHRENHEIT (42 DEGREES CELSIUS) AND THE COOLANT SENSOR IS NOT FAILED.

3. LARGE LEFT TO RIGHT TEMPERATURE SPREAD IN THE FOLLOWING POSITION(S): AUTO HEAT (BUICK)/AUTO UPPER, AND HEAT (OLDSMOBILE). THIS CONDITION MAY BE CONFIRMED BY VERIFYING THAT THE PASSENGER ZONE IS OFF, THEN USING A TECH I, OBSERVE PASS OFFSET. IT SHOULD SHOW A VALUE THAT CORRESPONDS TO THE OWNER'S CONCERN.

4. BUICK HVAC CONTROL HEAD MAY INTERMITTENTLY DISPLAY THREE DASHES, "---". THIS CONCERN MAY BE MORE LIKELY TO OCCUR IF THE RADIO AND/OR HVAC CONTROL SETTINGS ARE BEING ADJUSTED.

5. BLOWER REMAINS OFF IF KEYING UP THE VEHICLE IN AUTO (BUICK)/ AUTO FAN (OLDSMOBILE) MODES AFTER SELECTING MANUAL MODE (BILEVEL OR DEFOG - BUICK)/(UPPER, BILEVEL, OR DEFOG - OLDSMOBILE) DURING DELAY FOR COOLANT TEMPERATURE. ATTEMPTING TO SELECT MANUAL MODE WHILE THE BLOWER MOTOR IS OFF WILL KEEP THE BLOWER OFF. THE ONLY WAY TO OPERATE THE BLOWER MOTOR IS BY SELECTING OFF, THEN ANY OTHER MODE, OR BY MANUALLY ADJUSTING THE FAN SPEED.

6. OLDSMOBILE PASSENGER CONTROL HEAD DOES NOT ALWAYS CONTROL TO THE CONTROL HEAD SETTING WITH PASS TEMP ENABLED.

CORRECTION:

A NEW HVAC PROGRAMMER HAS BEEN RELEASED TO CORRECT THESE CONDITIONS (BUICK - P/N 16213006 AND OLDSMOBILE - P/N 16213005).

PARTS AVAILABILITY:

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: D0780 LABOR TIME: 0.5 HR. (OTHER HOURS) ADD: 0.3 HR. (FOR DIAGNOSIS)

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.