GM Service Manual Online
For 1990-2009 cars only

With this system you can control the heating, cooling and ventilation for your vehicle. If your vehicle has the remote start feature, the climate control system will function as part of the remote start feature. See Remote Keyless Entry (RKE) System Operation .


Object Number: 918777  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 may 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.

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 your 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 splits the air between the windshield and the floor outlets with a small amount directed to the side windows. When you select this mode, the system turns off recirculation automatically. The air-conditioning compressor will run unless the outside temperature is at or below freezing. The air-conditioning compressor operates although the indicator light will not be 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 your vehicle. The air-conditioning compressor will run unless the outside temperature is at or below freezing. The air-conditioning compressor operates although the indicator light will not be 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 will turn on. If the button is pressed again, the light will turn 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.
Temperature Control: Turn the center knob clockwise or counterclockwise to increase or decrease the temperature inside your vehicle.

When it is cold outside 0°F (-18°C) or lower, use the engine coolant heater, if equipped, to provide warmer air faster to your vehicle. An engine coolant heater warms the coolant that the engine uses to provide heat to warm the inside of your vehicle. For more information, see Engine Coolant Heater .

(Outside Air): Press the right side of this button to turn the outside air mode on. When this mode is selected, air from outside the vehicle circulates throughout the vehicle. When the button is pressed, an indicator light comes on to let you know that it is activated. The outside air mode can be used with all modes, but it cannot be used with the recirculation mode. Pressing this button cancels the recirculation mode.

(Recirculation): Press the left side of the button to turn the recirculation mode on. When recirculation mode is selected, the air inside the vehicle will be recirculated through the climate control system and the vehicle, not from outside your vehicle. This mode is helpful when you are trying to limit odors from entering your vehicle and for maximum air conditioning performance in hot weather. When the button is pressed, an indicator light above the button comes on to let you know that it is activated. The recirculation indicator light will blink three times if you try to use recirculation in a mode that it can not be used in. Only use this mode when it is needed for comfort, since window fogging rapidly occurs if the air conditioning compressor is not engaged. Pressing this button will cancel the outside air mode. When you switch 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 may occur.

(Air Conditioning): Press this button to turn the air conditioning system on or off. When the air conditioning button is pressed, an indicator light comes on to let you know that air conditioning is activated.

The air-conditioning system removes moisture from the air, so you may sometimes notice a small amount of water dripping underneath your vehicle while idling or after turning off the engine. This is normal.

Maximum Air Conditioning

On hot days, open the windows to let hot inside air escape; then close them. This helps to reduce the time it takes for your vehicle to cool down. It also helps the system to 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 may cause the air inside of your vehicle to become too dry. To prevent this from happening, after the air in your vehicle has cooled, turn the recirculation mode off.

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 let you know 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 will turn 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 will remain on once the button is pressed.

If your vehicle has the remote start feature, the rear defogger will automatically be turned on if it is cold outside. When the vehicle transitions out of the remote start mode, the rear defogger will turn off. See Remote Keyless Entry (RKE) System Operation .

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.