POOR AUTO CLIMATE CONTROL/SYSWARM IN COLD/ COLD IN WARM

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

VEHICLES AFFECTED: 1992-93 "H" 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 getting the correct air temperature for control due to lack of air flow across the sensor.

CORRECTION:

1. Check the aspirator for the in car sensor by making a patch from ordinary copier paper to the following dimensions. 2. Put the test parch on the in car sensor 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.

WARRANTY INFORMATION:

For vehicles repaired under warranty use:

Labour Time: 0.4 hrs.

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.