Auto Climate Control System - Poor Performance

Bulletin Number: 93-1-11
Reference Number: 201106
Publish Date: 12/92

Subject:
POOR AUTO CLIMATE CONTROL/SYSTEM GETS TOO WARM ON COLD START OR COOLS TOO MUCH IN WARM WEATHER (CHECK ASPIRATOR)

Models Affected:
1992-93 BONNEVILLE MODELS

CONDITION:

Some 1992-93 Pontiac Bonnevilles with C68 may experience an Automatic Climate Control problem where on cold days when first started, the vehicle heats too much, or on hot days, the vehicle cools too much.

CAUSE:

The in car sensor is not reading the correct air temperature for control due to lack of air flow across the sensor.

CORRECTION:





1. Check the aspirator for proper air flow to the in car sensor by making a patch from ordinary copier paper to the following dimensions.

2. Put the test patch on the in car sensor grille opening and turn the fan to speed number 3. The aspirator should hold the patch in place.

IF NOT:

3. Remove the trim plate that covers the in car sensor opening. Check for the donut gasket that fits around the sensor housing. If the gasket is missing, replace with P/N 12536297.

4. If the gasket is in place, install the test patch on the sensor face. Recheck as in Step 2. The aspirator should hold the patch in place.

IF NOT:

5. Check the aspirator hose for kinks, restrictions, or mis-routing and correct as necessary.

6. Reinstall the donut gasket and make sure that the lip of the gasket over-hangs the sensor edge by 3-5 mm so that the trim plate has enough gasket to provide a seal when installed.

7. Reinstall the trim plate.

8. Retest the aspirator with the test patch as in Step 2.

Parts are currently available from GMSPO.

WARRANTY INFORMATION:

Labor Operation No.: T5319
Labor Time: 0.4 hrs.