GM Service Manual Online
For 1990-2009 cars only

With this system you can control the heating, cooling, and ventilation for your vehicle.


Object Number: 867519  Size: B2
(Fan): Turn the left knob clockwise or counterclockwise to increase or decrease the fan speed. If the knob is in off mode, outside air will still enter the vehicle, and will be directed based on the position of the mode knob. The temperature can still be adjusted using the temperature knob.

Turn the right knob clockwise or counterclockwise to direct the airflow inside of your vehicle.

To change the current mode, select one of the following:

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

(Bi-Level): This mode directs about half of the air to the instrument panel outlets; then directs most of the remaining air to the floor outlets. A little air is directed toward the windshield and the side window outlets. Cooler air is directed to the upper vents and warmer air to the floor outlets.

(Floor): This mode directs most of the air to the floor outlets with a little air directed to the windshield and the side window outlets. The recirculation button cannot be selected while in floor mode.

(Recirculation): Recirculation mode is used to recirculate the air inside of your vehicle. When this button is pressed, an indicator light in the button will come on to let you know that it is active. Use this mode to help prevent outside odors and/or dust from entering your vehicle or to help cool the air inside of your vehicle more quickly. The air conditioning compressor will also come on when this mode is activated. While in recirculation mode, the windows may fog when the weather is cold and damp. To clear the fog, select either the defog or defrost mode and increase fan speed. Defog and defrost modes are described later in this section.

Driver's Side Temperature Knob: The lever on the left side of the climate control panel is used to raise or lower the temperature on the driver's side of the vehicle. Slide the lever up or down to adjust the temperature.

Passenger's Side Temperature Knob: The lever on the right side of the climate control panel is used to raise or lower the temperature on the passenger's side of the vehicle. Slide the lever up or down to adjust the temperature. This lever also adjusts the temperature to the rear seat outlets.

When the temperature outside is 0°F (-18°C) or lower, use the engine coolant heater, if the vehicle has one, to provide warmer air, faster to your vehicle.

(Air Conditioning): Press this button to turn the air conditioning system on or off. When the button is pressed, an indicator light will come on and the system will begin to cool and dehumidify the air inside of your vehicle. Running the air conditioning compressor helps to avoid fogging the inside windows on rainy and humid days when the temperature is above freezing. It is best not to use the recirculation mode, except when maximum air conditioning performance is needed. You may notice a slight change in engine performance when the air conditioning compressor shuts off and turns on again. This is normal.

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 clockwise or counterclockwise to select one of the following modes:

(Defog): This mode directs the air to the floor outlets, windshield and side window outlets. The recirculation button cannot be selected while in defog mode.

(Defrost) : This mode directs most of the air to the windshield and the side window outlets, with only a little air directed to the floor outlets. The air conditioning compressor may run to dehumidify the air to prevent window fogging. The recirculation button cannot be selected while in defrost mode. Do not drive the vehicle until all the windows are clear.

Rear Window Defogger

The lines you see on the rear window warm the glass.

(Rear): Press this button to turn the rear window defogger on or off. An indicator light in the button will come on to let you know that the rear window defogger is active. The rear window defogger will automatically turn off approximately ten minutes after the button is pressed.

If your vehicle is equipped with heated mirrors, this button will activate them.

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.