GM Service Manual Online
For 1990-2009 cars only

Your vehicle may have the dual automatic climate control system. With this system you can control the heating, cooling, and ventilation for your vehicle.


Object Number: 806283  Size: B2

Automatic Operation

AUTO (Automatic): When the driver's temperature knob is pressed to select AUTO and the temperature is set, the system will automatically control the inside temperature, the air delivery and the fan speed. AUTO will also appear on the display.

To place the entire system in automatic mode, do the following:

  1. Press the driver's temperature knob to turn the system on.
  2. Adjust the temperature to a comfortable setting.
  3. Choosing the coldest or warmest temperature will not cause the system to heat or cool any faster.

    In cold weather, the system will start at reduced fan speeds to avoid blowing cold air into your vehicle until warmer air is available. Then, as the air warms, it will be delivered through the instrument panel outlets. The length of time needed for warm up will depend on the outside temperature and the length of time that has elapsed since your vehicle was last driven.

  4. Adjust the PASS TEMP indicator that is located below the temperature display. If only the larger center bar is lit, the passenger side will be adjust to the same temperature setting as the driver side. Each bar that is lit to the + side of the center bar indicates that the passenger side will control to a warmer setting than the driver side. Each bar lit to the -- side of the center bar indicates that the passenger side will control to a cooler setting than the driver side.
  5. Wait for the system to regulate. This may take from 10 to 30 minutes. Then adjust the temperature as necessary.
  6. To turn the system off, press the passenger's knob.

Manual Operation

MODE: Press this button to manually change the direction of airflow in your vehicle; keep pressing the button until the desired mode appears on the display.

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 approximately half of the air to the instrument panel outlets, then directs the remaining air to the floor outlets and the defroster and 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. Use this mode to send air to the rear of the vehicle. Keep the area under the front seats free of objects that could obstruct airflow to the rear of the vehicle.

The MODE button can also be used to select defog. For more information, see "Defogging and Defrosting" later in this section.

(Fan): Press this button to increase to decrease the fan speed; keep pressing the up or down arrow until the desired fan speed appears on the display.

VENT: Press this button to turn the outside air mode on or off. When this mode is on, outside air will be circulated throughout your vehicle. VENT can be used with all modes, but it cannot be used with the recirculation mode.

(Recirculation): This mode keeps outside air from coming in the vehicle. It can be used to prevent outside air and odors from entering your vehicle or help heat or cool the air inside your vehicle more quickly. Press this button to turn the recirculation mode on or off. When the button is pressed, an indicator light will come on. The air-conditioning compressor also comes on. The recirculation mode can be used with vent and bi-level modes, but it cannot be used with floor, defog, defrost or outside air modes.

Temperature Control: Use the DRIVER knob to increase or decrease the air temperature inside your vehicle. If the front passenger would like the temperature to be warmer or cooler, use the PASS knob to adjust the passenger's temperature.

Air Conditioning: The air-conditioning compressor will automatically come on when a temperature cooler than the interior temperature is chosen using the temperature knobs.

You may notice a slight change in engine performance when the air-conditioning compressor shuts off and turns on again. This is normal. The system is designed to make adjustments to help with fuel economy while still maintaining the selected temperature.

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.

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.

Defogging and Defrosting

Fog on the inside of windows is a result of high humidity, or moisture, condensing on the cool window glass. This can be minimized if the climate controls system is used properly. There are two modes 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.

Use the MODE button to select the defog mode.

(Defog): This mode directs air to the windshield and the floor outlets. When you select this mode, the system turns off recirculation and runs the air-conditioning compressor unless the outside temperature is at or below freezing. The recirculation mode cannot be selected while in the defog mode.

Press the defrost button to select defrost.

(Defrost): This mode directs most of the air to the windshield and the side window outlets, with some air directed to the floor outlets. In this mode, the system will automatically turns off recirculation and run the air-conditioning compressor, unless the outside temperature is at or below freezing. Recirculation cannot be selected while in the defrost mode.

Do not drive the vehicle until all the windows are clear.

Rear Window Defogger

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

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.

The rear window defogger will turn off approximately 10 minutes after the button is pressed. If turned on again, the defogger will only run for approximately five 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 has heated outside rearview mirrors, the mirrors will heat to help clear fog or frost from the surface of the mirror when the rear window defog button is pressed.

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.