A/C AIR FROM DEFROST VENTS IN VENT MODE (REPL. A/C CONTROL). Buick Coachbuilder 1994

SUBJECT: A/C AIR FROM DEFROST VENTS IN VENT MODE (REPLACE A/C CONTROL HEAD)

MODELS: 1994 BUICK ROADMASTER WITH RPO C68

THIS BULLETIN IS BEING REVISED TO CORRECT WARRANTY INFORMATION - LABOR OPERATION NUMBER. PLEASE DISCARD BULLETIN 431204.

CONDITION:

A CUSTOMER MAY DESCRIBE THIS CONDITION AS BEING IN "DEFROST" MODE ALTHOUGH THE A/C CONTROL HEAD DISPLAYS THAT IT IS IN THE "VENT" MODE. THIS CONDITION HAPPENS WHEN EXITING FROM THE "DEFROST" MODE IF THE PREVIOUS MODE WAS "AUTO VENT".

CAUSE:

WHILE IN THE "DEFROST" MODE, IF THE "DEFROST" BUTTON IS PRESSED AGAIN, THE SYSTEM WAS DESIGNED TO RETURN TO THE PREVIOUS MODE. HOWEVER, IF THE PREVIOUS MODE WAS "AUTO-VENT" THE SYSTEM WILL RETURN TO THE "AUTO" (COMPRESSOR ON) AND THE DISPLAY ON THE CONTROL HEAD WILL SHOW "AUTO-VENT". THIS IS DUE TO A SOFTWARE CONDITION INSIDE THE CONTROL HEAD.

CORRECTION:

TO CORRECT, REPLACE THE A/C CONTROL HEAD WITH A NEW HEAD, P/N 16199483, FOLLOWING PROCEDURES IN THE SERVICE MANUAL, SECTION 1C.

PART AVAILABILITY:

PARTS ARE EXPECTED TO BE AVAILABLE ON 1/31/94.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE: LABOR OPERATION: D0362 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.