A/C ODOR PRIMARILY UPON START UP

REVISION 06/14/93

THIS BULLETIN HAS BEEN REVISED DUE TO REVISED WIRING DIAGRAMS AND DUE TO A REDUCED WATER RETENTION IN THE ORIGINAL EQUIPMENT, THE EVAPORATO REPLACEMENT HAS BEEN ELIMINATED ON THE 1990 ELDORADOS, SEVILLES, AND ALLANTES. OTHER DIVISIONS HAVE ALSO BEEN ADDED.

REVISION 03/29/93

THIS BULLETIN IS BEING REVISED TO UPDATE THE PROCEDURES AND WIRING DIAGRAMS AND TO INCLUDE THE 1991-93 MODEL YEARS.

REVISION 07/07/93

THIS BULLETIN IS BEING REVISED TO UPDATE THE "TABLE I" PART NUMBERS AND THE 1985-1993 DEVILLE/FLEETWOOD (FWD)/SIXTY SPECIAL WIRING DIAGRAM.

REVISION: 09/06/94

THIS BULLETIN IS BEING REVISED TO INCLUDE THE 1994 MODELS WITH AN AFTERBLOW MODE AND TO ADD PROCEDURE "D".

PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: CADILLAC T-93-75A GM OF CANADA 93-1B-121

REVISED: 11/08/94

THIS BULLETIN IS BEING REVISED TO PROVIDE A NEW CHART "B" WITH REVISED LABOR TIME AND TO ADD THE 1995 MODEL YEAR (WHERE APPLICABLE). ALL OTHER ARTWORK REMAINS THE SAME. PLEASE DISCARD BULLETIN 911204 (GROUP REFERENCE 1 - HVAC). ----------------------------------------------------------------------

SUBJECT: A/C ODOR PRIMARILY UPON START UP IN HUMID CLIMATES (SERVICE PROCEDURES)

MODELS: 1985-93 CADILLAC FLEETWOOD 1985-95 CADILLAC DEVILLE 1986-95 CADILLAC ELDORADO AND SEVILLE 1987-93 CADILLAC ALLANTE 1994-95 CADILLAC CONCOURS

CONDITION:

SOME OWNERS MAY COMMENT ON ODORS EMITTED FROM THE AIR CONDITIONING SYSTEM PRIMARILY AT START UP IN HOT, HUMID CLIMATES.

CAUSE:

THIS ODOR MAY BE THE RESULT OF FOREIGN MATERIAL IN THE HEATER/ EVAPORATOR CASE AND/OR MICROBIAL GROWTH ON THE EVAPORATOR CORE.

CORRECTION:

TO ADDRESS THIS CONDITION, USE THE ATTACHED "CHART A" IN ACCORDANCE WITH THE YEAR AND MODEL OF THE VEHICLE TO CHOOSE THE APPROPRIATE PROCEDURE(S).

PROCEDURE A (REPLACE EVAPORATOR CORE):

THIS PROCEDURE IS APPROPRIATE WHEN THE VEHICLE IS ORIGINALLY EQUIPPED WITH A 14 FPI (FINS PER INCH) EVAPORATOR CORE WHICH MAY RETAIN A HIGHER VOLUME OF WATER. THE 11 FPI SERVICE CORES LISTED IN THIS BULLETIN ARE FOR "A/C ODOR ONLY" BECAUSE FEWER FINS WILL DECREASE WATER RETENTION WITHIN THE EVAPORATOR CASE.

1. REMOVE EVAPORATOR CORE AS DESCRIBED IN THE APPROPRIATE SERVICE INFORMATION MANUAL.

2. DISCARD DRAIN GROMMET ON 1985-1988 VEHICLES.

3. CLEAN HEATER/EVAPORATOR MODULE OF ALL DEBRIS.

4. IF A LARGE AMOUNT OF FOREIGN MATERIAL IS PRESENT IN THE HEATER/EVAPORATOR CASE, SEAL THE AIR INLET SCREEN AROUND THE WINDSHIELD POST HOLES AND FENDER EDGES.

5. INSTALL THE APPROPRIATE SERVICE EVAPORATOR FROM "TABLE I" BELOW:

"TABLE I"

MODEL P/N

1985-1987 C-CAR 1986-1989 E/K-CAR 52454626 1987-1989 V-CAR

1988 C-CAR 52455852

1989-1990 C-CAR 52455349

1991 C-CAR 52455813 (PRIOR TO VIN BREAKPOINT 304903)

PROCEDURE B (CLEAN AND DISINFECT):

THIS PROCEDURE IS FOR VEHICLES WHICH ALREADY HAVE AN 11 FPI EVAPORATOR CORE OR A TILTED EVAPORATOR CORE WHICH HAS LOWER WATER RETENTION. THE FOLLOWING STEPS WILL PROVIDE A DISINFECTING OPERATION TO KILL ANY MICROBIAL GROWTH WHICH MAY HAVE DEVELOPED ON THE EVAPORATOR CORE OR WITHIN THE CASE.

CAUTION:

THIS PROCEDURE SHOULD ONLY BE PERFORMED ON A COLD CAR. IRRITATING VAPORS CAN FORM IN THE ENGINE COMPARTMENT IF THE DISINFECTANT COMING FROM THE DRAIN OUTLET CONTACTS HOT ENGINE COMPONENTS.

DISINFECTANT CAN CAUSE SUBSTANTIAL, BUT TEMPORARY, EYE INJURY. DO NOT GET IN EYES OR ON CLOTHING.

WASH THOROUGHLY WITH SOAP AND WATER AFTER HANDLING.

FIRST AID - IF DISINFECTANT GETS INTO EYES, HOLD EYELIDS OPEN AND FLUSH WITH A STEADY, GENTLE STREAM OF WATER FOR 15 MINUTES. OBTAIN MEDICAL ATTENTION IF IRRITATION PERSISTS.

1. PUT ON RUBBER GLOVES AND SAFETY GOGGLES.

2. POUR THE SMALL BOTTLE OF GOODWRENCH AIR CONDITIONING SYSTEM DISINFECTANT KIT, P/N 25533404, INTO THE LARGE BOTTLE. SEAL AND INVERT THE CONTAINER ONCE OR TWICE TO MIX CONTENTS.

3. CONNECT BATTERY CHARGER TO AVOID DRAINING THE BATTERY DURING CLEANING PROCEDURE.

4. REMOVE POWER MODULE AS DESCRIBED IN THE SERVICE INFORMATION MANUAL LEAVING WIRING CONNECTORS ATTACHED.

NOTICE: DO NOT ALLOW THE METAL HEAT SINK OF THE POWER MODULE TO BECOME GROUNDED TO ANY METAL SURFACE AS INTERNAL CIRCUITRY DAMAGE MAY RESULT.

CAUTION:

CARE SHOULD BE TAKEN TO PREVENT PERSONAL INJURY OR BURN IF THE POWER MODULE HEAT SINK IS HOT.

5. INSPECT HEATER/EVAPORATOR CASE FOR DEBRIS. REMOVE ANY DEBRIS PRESENT THROUGH THE POWER MODULE OPENING. IF DEBRIS IS EMBEDDED INTO THE EVAPORATOR CORE FACE AND CANNOT BE REMOVED, THE CORE WILL HAVE TO BE REMOVED FROM THE VEHICLE AND CLEANED. IF REFRIGERANT OIL IS EVIDENT ON THE FACE OF THE EVAPORATOR CORE, A REFRIGERANT LEAK IS PRESENT AND THE EVAPORATOR SHOULD BE REPLACED. IF A LARGE AMOUNT OF DEBRIS IS PRESENT IN THE HEATER/EVAPORATOR CASE, THE AIR INLET SCREEN SHOULD BE SEALED AROUND THE WINDSHIELD WIPER POST HOLES AND FENDER EDGES.

6. TURN IGNITION ON WITHOUT STARTING ENGINE AND ENTER DIAGNOSTICS. COMMAND THE AIR MIX VALVE (DOOR) TO THE MAXIMUM COLD POSITION AND THE BLOWER TO "LOW" SPEED.

7. OPEN ALL WINDOWS AND DOORS. EXIT VEHICLE.

8. PLACE DRAIN PAN WITH AT LEAST A TWO-QUART CAPACITY BELOW THE HEATER/EVAPORATOR DRAIN HOLE TO CATCH DISINFECTANT AND RINSE WATER RUNOFF.

9. POSITION A PEDESTAL FAN AND TURN ON "HIGH" TO PROVIDE CROSS VENTILATION DURING CLEANING PROCEDURE.

10. USE KENT-MOORE TOOL J-36645, OR EQUIVALENT, SIPHON-TYPE PARTS CLEANING SPRAY GUN CAPABLE OF DELIVERING TWO OUNCES PER MINUTE OF LIQUID WHEN DRIVEN WITH SHOP AIR AT 80-90 PSI. INSERT THE NOZZLE OF THE SPRAY GUN THROUGH THE POWER MODULE OPENING AND INSERT THE SIPHON HOSE INTO CONTAINER OF DISINFECTANT. TAKE CARE TO PLACE THE BOTTLE OF DISINFECTANT IN A SECURE, UPRIGHT POSITION TO AVOID SPILLING THE CONTENTS. DIRECT SPRAY TOWARD EVAPORATOR FACE TAKING EXTRA CARE TO ENSURE ADEQUATE COVERAGE OF THE CORNERS AND EDGES, COMPLETELY SATURATING THE ENTIRE CORE. USE THE ENTIRE CONTAINER OF SOLUTION.

CAUTION:

DO NOT ALLOW DISINFECTANT TO COME IN CONTACT WITH HOT ENGINE COMPONENTS SUCH AS THE EXHAUST MANIFOLD AS THIS MAY RESULT IN TOXIC FUMES.

11. REACH INTO THE VEHICLE AND TURN THE IGNITION TO THE OFF POSITION, AND ALLOW THE CORE TO SOAK FOR FIVE MINUTES.

12. REACH INTO VEHICLE AND START ENGINE.

13. THOROUGHLY RINSE THE EVAPORATOR CORE WITH ONE QUART OF CLEAN WATER USING THE SPRAY GUN TO RINSE ANY DISINFECTANT RESIDUE.

14. REACH INTO THE VEHICLE AND TURN THE IGNITION TO THE OFF POSITION AND THEN REINSTALL POWER MODULE.

CAUTION:

CARE SHOULD BE TAKEN IN HANDLING THE POWER MODULE TO PREVENT BURNS OR PERSONAL INJURY FROM THE HEAT SINK WHICH MAY BE HOT.

15. DISPOSE OF DISINFECTANT AND RINSE WATER RUNOFF COLLECTED IN DRAIN PAN INTO A SANITARY DRAIN SYSTEM.

16. DISCONNECT BATTERY CHARGER.

PROCEDURE C (INSTALL AFTERBLOW MODULE, P/N 25533406):

THE INSTALLATION OF THE AFTERBLOW MODULE AS OUTLINED IN THE FOLLOWING STEPS WILL TURN THE BLOWER MOTOR ON APPROXIMATELY 50 MINUTES AFTER THE VEHICLE IGNITION IS TURNED OFF IF THE COMPRESSOR WAS ENGAGED FOR MORE THAN FOUR MINUTES DURING THE LAST IGNITION CYCLE. DURING THE FIRST 50 MINUTES AFTER THE VEHICLE IGNITION IS TURNED OFF, THE EVAPORATOR WILL ACCUMULATE WATER CONDENSATE ON THE CORE. CYCLING THE BLOWER MOTOR AT HIGH SPEED FOR APPROXIMATELY FIVE MINUTES WILL FORCE THE WATER TO BE SHED FROM THE CORE AND TO DRAIN FROM THE EVAPORATOR CASE. THIS PROCEDURE IS USED TO PREVENT THE RECURRENCE OF THE ODOR. BE SURE TO ADVISE THE OWNER OF THIS CHANGE IN OPERATION.

1. IF VEHICLE IS EQUIPPED WITH PASSENGER SIDE AIR BAG, REFER TO THE APPROPRIATE SERVICE INFORMATION MANUAL AND FOLLOW THE PROCEDURE TO DISABLE THE SIR.

2. REMOVE CLOSE OUT PANEL(S) AND GLOVE BOX AS REQUIRED TO GAIN ACCESS TO THE CIRCUITS SHOWN IN THE ATTACHED APPLICABLE WIRING DIAGRAM. REFER TO THE APPROPRIATE SERVICE INFORMATION MANUAL FOR COMPONENT LOCATION AND SERVICE PROCEDURES.

3. SPLICE, CLIP, AND SOLDER (REFER TO SECTION 8A OF THE APPROPRIATE SERVICE INFORMATION MANUAL FOR SPLICING INSTRUCTIONS) THE VARIOUS LEADS TO THE AFTERBLOW MODULE WIRING HARNESS WITH THE CIRCUITS SHOWN IN THE CORRESPONDING WIRING DIAGRAM ON THE FOLLOWING PAGES. DISCONNECT THE WIRING HARNESS FROM THE AFTERBLOW MODULE AND CONNECT THE BLACK/WHITE GROUND LEAD FIRST BEFORE COMPLETING THE REMAINING SPLICES. SINCE A MAJORITY OF CIRCUITS TO BE SPLICED ARE LOW CURRENT CIRCUITS, CARE SHOULD BE TAKEN TO ASSURE THAT THE SPLICES ARE COMPLETED AND SOLDERED CORRECTLY.

4. TEST OPERATION OF AFTERBLOW AS FOLLOWS:

A. START VEHICLE.

B. TURN A/C SYSTEM ON TO ENGAGE COMPRESSOR.

C. CONNECT JUMPER WIRE TO APPLY BATTERY VOLTAGE TO OPEN POSITION PIN H (GREEN WIRE) OF AFTERBLOW MODULE FOR AT LEAST 30 SECONDS WITH COMPRESSOR ENGAGED.

D. TURN VEHICLE IGNITION OFF.

E. BLOWER SHOULD COME ON AFTER APPROXIMATELY 10 SECONDS FOR ONE SECOND AND THEN GO OFF.

F. DISCONNECT JUMPER WIRE FROM PIN H (GREEN WIRE).

5. ADD FOAM INSULATION AS NECESSARY TO ENSURE RATTLE-FREE INSTALLATION OF THE AFTERBLOW MODULE.

NOTE: THE AFTERBLOW MODULE AFFECTS AFTERMARKET AND GOODWRENCH THEFT ALARM SYSTEMS. CYCLING THE BLOWER MOTOR WITH KEY OFF COULD TRIGGER ALARMS THAT SENSE BATTERY VOLTAGE CHANGES OR CURRENT DRAIN.

PROCEDURE D (ENABLING AFTERBLOW MODE)

THIS PROCEDURE IS FOR 1994-95 CADILLAC CONCOURS, DEVILLES, ELDORADOS AND SEVILLES. THESE VEHICLES HAVE AN AFTERBLOW FEATURE TO ALLOW THE A/C BLOWER TO RUN AFTER VEHICLE IS SHUT DOWN. TO PROPERLY ENABLE THE AFTERBLOW MODE, THE FOLLOWING STEPS MUST BE FOLLOWED.

ENABLING OF THE AFTERBLOW MODE ALLOWS THE BLOWER MOTOR TO TURN "ON" 45 MINUTES AFTER THE VEHICLE IGNITION IS TURNED "OFF" IF, DURING THE LAST IGNITION CYCLE, THE COMPRESSOR WAS ENGAGED FOR MORE THAN THREE MINUTES CUMULATIVE RUN TIME. THE AMBIENT AT IGNITION "OFF" MUST HAVE BEEN ABOVE 80 DEGREES FAHRENHEIT (27 DEGREES CELSIUS). THE BLOWER WILL THEN RUN THREE MINUTES AND TURN "OFF".

IF NECESSARY, REFER TO SECTION 8C1 "IPC OVERRIDE DISPLAY" IN THE APPROPRIATE SERVICE MANUAL TO REVIEW OPERATION.

1. ENTER DIAGNOSTICS AND SELECT IPC OVERRIDE. 2. SELECT OUTPUT OVERRIDE OPTION IS08 TO DISPLAY "OPTION I" VALUE. 3. USE THE "WARMER" BUTTON TO ADD FOUR (4) TO THIS VALUE TO ENABLE HVAC AFTERBLOW. - NORMAL IS08 VALUE FOR THE CONCOURS, DEVILLE, ELDORADO AND SEVILLE IS 8 WITH RTD (RSS) OR 0 WITH CCR. 4. WHEN THE CORRECT NUMBER IS REACHED, SIMULTANEOUSLY PRESS AND HOLD THE "ECON" AND "FRONT DEFROST" BUTTONS FOR THREE SECONDS TO PERMANENTLY STORE THE CORRECT VALUE.

NOTE: THE OWNER SHOULD BE ADVISED WHEN THIS MODE IS ENABLED AND THE MODE'S FUNCTION AND PURPOSE.

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: D3320 (TO REPLACE EVAPORATOR CORE) D3319 (TO CLEAN AND DISINFECT) D3318 (TO INSTALL AFTERBLOW MODULE) D3317 (TO ENABLE AFTERBLOW MODE) SEE THE ATTACHED CHART "B" FOR APPROPRIATE LABOR TIME.

FIGURES: 0 ATTACHMENTS: 6

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.

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