INFO. ON SLOW TEMP. RESPONSE FROM HVAC SYS. AND DESCRIPTION. Buick Park Avenue 1998

THIS IS A MONTHLY SERVICE NEWSLETTER ARTICLE. THIS BULLETIN IS NOT INTENDED FOR PUBLICATION.

SUBJECT: INFORMATION ON SLOW TEMPERATURE RESPONSE FROM HVAC SYSTEM AND DESCRIPTION OF NORMAL OPERATION

MODELS: 1997-98 BUICK PARK AVENUE/ULTRA

FOR 1997 AND 1998 PARK AVENUES/ULTRAS, THE TYPICAL CUSTOMER CONCERNS FOR POOR AUTOMATIC RESPONSE OF THE HVAC SYSTEM ARE AS FOLLOWS:

HAVING TO DIAL TEMP UP AND DOWN TO MAINTAIN COMFORT.

BLOWER IS ON HIGH TOO LONG.

AUTO TEMPERATURE CONTROL DOESN'T RESPOND.

OTHER SIMILAR COMPLAINTS.

THE INSIDE TEMPERATURE SENSOR ASPIRATOR SYSTEM HAS BEEN IDENTIFIED AS A POSSIBLE SOURCE. TWO CONNECTIONS WITHIN THE ASPIRATOR SYSTEM COULD BE SUSPECT:

THE ASPIRATOR ADAPTER TO I/P TRIM PLATE CONNECTION.

ASPIRATOR HOSE TO ASPIRATOR MUFFLER CONNECTION.

THE FOLLOWING SEQUENCE WILL AID IN DETERMINING ASPIRATOR SYSTEM RELATED CONCERNS:

USE A TECH 2 TO CHECK CODES WITHIN THE HVAC SYSTEM.

REPAIR AND/OR CLEAR ANY CODES.

FROM THE TECH 2, READ THE INSIDE AIR TEMP SENSOR AND COMPARE TO A TEMP PROBE PLACED IN THE PASSENGER COMPARTMENT (BREATH TEMP).

THE DIFFERENCE BETWEEN THE TWO READINGS SHOULD BE AROUND 5-DEG FAHRENHEIT AFTER 20-30 MINUTES OF NORMAL VEHICLE OPERATION IN MODERATE AMBIENT TEMPS.

CHECK ASPIRATION BY PLACING A 35 MM SQUARE PIECE OF PAPER OVER THE ASPIRATOR GRILL (9 HOLES) IN THE CLUSTER TRIM PANEL TO THE RIGHT OF THE STEERING COLUMN.

START AT HIGH BLOWER AND MANUALLY DIAL DOWN TO LOW BLOWER.

THE PAPER SHOULD RETAIN TO GRILL AT ALL BLOWER SPEEDS EXCEPT LOW.

IF THERE IS NO RETENTION AT ALL OR THE PAPER FALLS AS MID-BLOWER SPEEDS ARE APPROACHED, ONE OF THE CONDITIONS STATED IN THE ABOVE SUSPECT AREAS IS LIKELY TO EXIST.

IF THERE CONTINUES TO BE WEAK OR NO ASPIRATION, CHECK THE CONNECTION BETWEEN THE ASPIRATOR HOSE AND ASPIRATOR MUFFLER. THIS CONNECTION IS UNDER THE I/P NEAR THE CENTER OF THE VEHICLE. TO REPAIR THIS CONNECTION PERFORM THE FOLLOWING SEQUENCE:

REMOVE THE DRIVER HUSH PANEL.

CORRECT THE CONNECTION BETWEEN THE MUFFLER AND THE HOSE.

EITHER REPAIR SHOULD ADDRESS THE ISSUE. IF COMPLAINTS PERSIST, REFER TO THE SERVICE MANUAL FOR SYSTEM PERFORMANCE IN SECTION 1B, CHARTS A + B.

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