HVAC AIR TEMP. TOO HOT/COLD INSPECT/REPAIR SENSOR HOSE

SUBJECT: LACK OF HVAC TEMPERATURE CONTROL (CORRECTIONS)

VEHICLES AFFECTED: 1991 NINETY-EIGHT/TOURING SEDAN

CONDITION:

----------- Some 1991 Ninety-Eight/Touring Sedans may experience HVAC air temperature being too warm during cold weather and/or too cold during warm weather, which may be caused by a pinched in-car sensor, hose, in-car sensor seal not sealing to instrument panel, or a defective outside temperature sensor.

CORRECTIONS:

------------ Pinched In-Car Sensor Hose: --------------------------- 1. Remove glove box tray to gain access to sensor hose. 2. Disconnect sensor hose at the plastic connector located near the instrument panel support bracket. 3. Pull the aspirator hose from the pinch point at the A/C duct to defrost duct interface. 4. Cut and remove the damaged portion of the hose and reconnect the remaining length.

In-Car Sensor Seal Not Sealing to Instrument Panel

1. Remove cluster trim plate. 2. Remove HVAC control head and radio. 3. Loosen both in-car sensor attaching screws and push down on the sensor while retightening the screws to seal the sensor to the instrument panel.

Defective Outside Temperature Sensor

1. Check resistance of outside temperature sensor. Resistance should be within 25 ohms of the values shown below for the temperature at which you are checking the sensor:

18 degrees C (65 degrees F) 1380 ohms 24 degrees C (75 degrees F) 1050 ohms 29 degrees C (85 degrees F) 840 ohms

2. If not within the above specifications, replace defective sensor.

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.