GM Service Manual Online
For 1990-2009 cars only

HVAC SYSTEM STUCK IN DEFROST MODE

SUBJECT: HVAC SYSTEM STUCK IN DEFROST MODE AFTER PROGRAMMER REPLACEMENT (EXCHANGE VACUUM HARNESS CONNECTOR FROM ORIGINAL PROGRAMMER)

MODELS: 1991-92 CADILLAC FLEETWOOD 1991-93 CADILLAC DEVILLE AND SIXTY SPECIAL

CONDITION:

SOME OWNERS MAY COMMENT THAT THE HVAC SYSTEM REMAINS STUCK IN THE "DEFROST" MODE AFTER A PROGRAMMER REPLACEMENT.

CAUSE:

THIS CONDITION MAY BE CAUSED BY THE SHAPE OF THE VACUUM HARNESS CONNECTOR INSIDE OF THE NEW PROGRAMMER.

CORRECTION:

THIS CONDITION MAY BE CORRECTED BY REMOVING THE VACUUM HARNESS CONNECTOR MANIFOLD FROM THE ORIGINAL PROGRAMMER AND EXCHANGING IT WITH THE REPLACEMENT PROGRAMMER. USE THE FOLLOWING PROCEDURE TO EXCHANGE THE VACUUM HARNESS CONNECTOR MANIFOLD.

REMOVE OR DISCONNECT:

1. RIGHT SIDE SOUND INSULATOR.

2. I/P COMPARTMENT.

3. VACUUM HARNESS AND ELECTRICAL CONNECTORS FROM PROGRAMMER.

4. PROGRAMMER FROM VEHICLE.

5. COVER FROM PROGRAMMER.

6. EXISTING VACUUM HARNESS FROM PROGRAMMER.

INSTALL OR CONNECT:

1. VACUUM HARNESS FROM ORIGINAL PROGRAMMER TO REPLACEMENT PROGRAMMER.

2. COVER TO PROGRAMMER.

3. PROGRAMMER TO VEHICLE.

4. VACUUM HARNESS AND ELECTRICAL CONNECTOR TO PROGRAMMER.

5. I/P COMPARTMENT.

6. RIGHT SIDE SOUND INSULATOR.

IF THE CONDITION IS NOT CORRECTED AFTER FOLLOWING THIS PROCEDURE, THE VACUUM HARNESS WILL REQUIRE REPLACEMENT.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

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

D0770 PROGRAMMER, AIR USE PUBLISHED CONDITIONING - R/R LABOR TIME

ADD: TRANSFER HVAC 0.2 HR PROGRAMMER VACUUM HARNESS

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.

COPYRIGHT 1996 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.