GM Service Manual Online
For 1990-2009 cars only

The heating, cooling and ventilation for the vehicle can be controlled with this system.


Object Number: 2047643  Size: B2
  1. Fan Control

  2. Recirculation

  3. Temperature Control

  4. Outside Air

  5. Air Delivery Mode Control

  6. Air Conditioning

  7. Rear Window Defogger

Operation

Temperature Control: Turn clockwise or counterclockwise to increase or decrease the temperature inside the vehicle. When it is cold outside 0°F (-18°C) or lower, use the engine coolant heater, if vehicle has one, to provide warmer air faster to the vehicle. An engine coolant heater warms the coolant the engine uses that provides heat to warm the inside of the vehicle. For more information, see Engine Coolant Heater.

(Fan Control): Turn clockwise or counterclockwise to increase or decrease the fan speed. The fan must be on to run the air-conditioning compressor.

Air Delivery Mode Control: Turn clockwise or counterclockwise to change the current airflow mode.

Select from the following:

(Vent): Air is directed to the instrument panel outlets.

(Bi-Level): Air is divided between the instrument panel and floor outlets. Some air will be directed toward the side windows.

(Floor): Air is directed to the floor outlets with some air directed to the windshield and side window outlets.

(Defog): This mode clears the windows of fog or moisture. Air is directed to the windshield and floor outlets, with some air directed to the side windows. When this mode is selected, the system automatically turns off recirculation and runs the air-conditioning compressor unless the outside temperature is at or below freezing. The air-conditioning compressor operates although the indicator light is not on. The air-conditioning indicator light turns off when defog is selected. If the air-conditioning button is pressed while in defog mode, the indicator light will turn on. If the button is pressed again, the light will turn off. The recirculation mode cannot be selected while in the defog mode. Do not drive the vehicle until all the windows are clear.

(Defrost): This mode quickly clears the windshield of fog or frost. Air is directed to the windshield with some air directed to the floor vents. In this mode, outside air is pulled into the vehicle. The air-conditioning compressor will not run unless the outside temperature is at or below freezing. The air-conditioning compressor operates although the indicator light is not on. The air-conditioning indicator light turns off when defrost is selected. If the air-conditioning button is pressed while in defrost mode, the indicator light turns on. If the button is pressed again, the light turns off. Recirculation cannot be selected while in the defrost mode.

To help clear the windshield quickly, do the following:

  1. Select .
  2. Select the highest temperature.
  3. Select the highest fan speed.
(Air Conditioning): Press to turn the air conditioning system on or off. An indicator light comes on to show it is on.

The air-conditioning system removes moisture from the air, so a small amount of water might drip under the vehicle while it is idling or after the engine is turned off is normal.

Maximum Air Conditioning

On hot days, open the windows to let hot inside air escape; then close them. This helps reduce the time it takes for the vehicle to cool down. It also helps the air conditioning system operate more efficiently.

For quick cool down on hot days, do the following:

  1. Select the vent mode.
  2. Select the highest fan speed.
  3. Select air conditioning.
  4. Select the recirculation mode.
  5. Select the coolest temperature.

Using these settings together for long periods of time can cause the air inside of the vehicle to become too dry. To prevent this from happening, after the air in the vehicle has cooled, turn the recirculation mode off.

(Outside Air): Press to turn the outside air mode on. An indicator light comes on to show that it is on. Air from outside the vehicle will circulate throughout the vehicle. The outside air mode can be used with all modes, but it cannot be used with the recirculation mode. Press to cancel the recirculation mode.

(Recirculation): Press to turn the recirculation mode on. An indicator light comes on to show that it is on. This mode recirculates and helps to quickly cool the air inside the vehicle. It can be used to prevent outside air and odors from entering the vehicle. The recirculation indicator light blinks three times if you try to use recirculation in a mode in which it cannot function. Pressing this button cancels the outside air mode. When switching to the defog or defrost modes the system automatically moves from recirculation to outside air. When the vehicle or fan is turned off and back on, the system defaults to outside air automatically. Only use recirculation mode when it is needed for comfort, since window fogging can occur.

Rear Window Defogger

The rear window defogger uses a warming grid to remove fog or frost from the rear window.

REAR: Press to turn the rear window defogger on or off. An indicator light comes on to show that the rear window defogger is on. Be sure to clear as much snow from the rear window as possible.

If driving below 50 mph (80 km/h), the rear window defogger turns off about 15 minutes after the button is pressed. If turned on again, the defogger only runs for about seven minutes before turning off. The defogger can also be turned off by turning off the engine.

If the vehicle's speed is maintained above 50 mph (80 km/h), the rear window defogger remains on once the button is pressed.

If the vehicle has heated outside mirrors, the surface of the outside mirrors heat when the rear window defogger is activated. See Outside Power Mirrors.

Notice: Do not use anything sharp on the inside of the rear window. If you do, you could cut or damage the warming grid, and the repairs would not be covered by the vehicle warranty. Do not attach a temporary vehicle license, tape, a decal or anything similar to the defogger grid.

Remote Start Climate Control Operation

For vehicles with the remote start feature, when it is activated the climate control system heats or cools the inside of the vehicle using the modes that were set before the vehicle was turned off. The climate control knobs will remain active during a remote start. However, the climate control buttons will be inactive until the ignition is turned on by the key. If the fan is off, the climate control system will not operate during remote start. See Remote Keyless Entry (RKE) System Operation.