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 Control

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

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

Mode Control

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 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 outlets 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.

(Recirculation): The recirculation mode is used to recirculate the air inside of your vehicle. 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. Press this button to turn the recirculation mode on or off. The light on the recirculation button will illuminate. Recirculation cannot be used in floor, defog or defrost modes. An indicator on the button will light up, flash three times and turn off when recirculation is selected in these modes. 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.

Temperature Control

Driver's Side: 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. This lever also adjusts the temperature to the center console outlets, if the vehicle has them.

Passenger's Side: 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.

(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. 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 the 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 one of the following modes:

(Defog): This mode directs the air to the floor outlets, windshield and the side window outlets. The air conditioning compressor will run automatically to dehumidify the air to prevent window fogging. The recirculation mode cannot be selected while in the 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 will run automatically to dehumidify the air to prevent window fogging. The recirculation mode cannot be selected while in defrost mode. Do not drive the vehicle until all the windows are clear.

Rear Window Defogger

If your vehicle has this feature, the rear window defogger uses a warming grid to remove fog from the rear window.

If your vehicle has a sliding rear window, you will not have a rear window defogger.

(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 activated. This button will also activate the heated mirrors, if the vehicle has them.

The rear window defogger will automatically turn off several minutes after the button is pressed. Pressing the button while the defogger is running can also turn off the defogger.

(Mirror): If your vehicle does not have a rear defogger and has heated mirrors, your vehicle will have this button to activate the heated 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.