GM Service Manual Online
For 1990-2009 cars only

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


Object Number: 1697967  Size: B2

Operation

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

To change the air delivery settings, turn the right knob to select one of the following:

(Vent): This mode directs air to the instrument panel outlets.

(Bi-Level): This mode directs half of the air to the instrument panel outlets, and the remaining air to the floor outlets. Some air will be directed toward the side windows.

(Floor): This mode directs most of the air to the floor outlets with some air directed to the side window outlets and windshield.

(Outside Air): Press the right side of this button to turn the outside air mode on. An indicator light comes on to show that it is activated. 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 this button to cancel the recirculation mode.

(Recirculation): Press the left side of the button to turn the recirculation mode on. An indicator light comes on to show that it is activated. The air inside the vehicle will be recirculated through the climate control system and the vehicle, not from outside the vehicle. This mode is helpful when trying to limit odors from entering the vehicle and for maximum air conditioning performance in hot weather. The recirculation indicator light blinks three times if you try to use recirculation in a mode in which it cannot function. Pressing this button will cancel 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.

Temperature Control: Turn the center knob 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 .

(Air Conditioning): Press this button to turn the air conditioning system on or off. An indicator light comes on to show it is activated.

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.

Defogging and Defrosting

Fog on the inside of windows is a result of high humidity (moisture) condensing on the cool window glass. This can be minimized if the climate control system is used properly. There are two modes to choose from to clear fog or frost from the windshield. Use the defog mode to clear the windows of fog or moisture and warm the passengers. Use the defrost mode to remove fog or frost from the windshield more quickly.

Turn the right knob to select the defog or defrost mode.

(Defog): This mode divides the air between the windshield and the floor outlets with a small amount directed to the side windows. When this mode is selected, the system automatically turns off recirculation. The air-conditioning compressor will 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 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 directs most of the air to the windshield with some air directed to the floor vents. In this mode, the system automatically forces outside air 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 the defrost mode.
  2. Select the highest temperature.
  3. Select the highest fan speed.

Rear Window Defogger

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

REAR: Press this button to turn the rear window defogger on or off. An indicator light comes on to show that the rear window defogger is activated. 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 pressing the button again or by turning off the engine.

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

If your 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

If your vehicle has the remote start feature and 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 .