GM Service Manual Online
For 1990-2009 cars only

The heating, cooling, and ventilation for the vehicle can be controlled with this system. For vehicles with the remote start feature, the climate control system functions as part of the remote start feature. See Remote Keyless Entry (RKE) System Operation.


Object Number: 2042706  Size: G3
  1. Fan Control

  2. Temperature Control

  3. Air Delivery Mode Control

  4. Air Conditioning

  5. Outside Air

  6. Recirculation

  7. Rear Window Defogger

(Fan Control): Turn clockwise or counterclockwise to increase or decrease the fan speed. To turn the fan off, turn the left knob all the way counterclockwise. In any setting other than off, the fan runs continuously with the ignition on. There will be some airflow noticeable from the various outlets when driving, even with the fan in the off position. To turn off the air completely, turn the fan to and select the recirculation button.

Temperature Control: Turn clockwise or counterclockwise to increase or decrease the temperature inside the vehicle.

Air Delivery Mode Control: Turn clockwise or counterclockwise to change the current airflow mode.

Select from the following air delivery modes:

(Vent): Air is directed to the instrument panel outlets.

(Bi-Level): Air is divided between the instrument panel and the floor outlets.

(Floor): Air is directed to the floor outlets with some air directed to the windshield. When this mode is selected, the system turns the recirculation mode off. Recirculation mode cannot be selected while in floor mode. This helps prevent window fogging.

(Defog): This mode clears the windows of fog or moisture. Air is directed to the floor outlets, with some air directed to the windshield and side window outlets. In this mode, the system turns the recirculation mode off and runs the air conditioning compressor unless the outside air is at or below freezing. Recirculation mode cannot be selected while in defog mode. This helps prevent window fogging.

(Defrost): This mode removes fog or frost from the windshield more quickly. Air is directed to the windshield and the side window outlets. In this mode, the system turns the recirculation mode off automatically and runs the air conditioning compressor unless the outside air is at or below freezing. Recirculation mode cannot be selected while in defrost mode. This helps prevent window fogging. For best results, clear all snow and ice from the windshield before defrosting.

(Air Conditioning): Press to turn the air conditioning system on or off. An indicator light comes on to show that the air conditioning is on. The air conditioning can be selected in any mode as long as the fan is on and the outside temperature is above freezing. A flashing indicator light indicates that the air conditioning compressor is currently not available.

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 and helps the system to operate more efficiently.

For quick cool down on hot days, select the following settings together:

  1. Select mode.
  2. Select .
  3. Turn the on.
  4. Select the coolest temperature and highest fan speed.
  5. Once the vehicle's interior temperature is below the outside temperature, select recirculation mode for enhanced cooling.

Using these settings together for long periods of time may cause the air inside the vehicle to become too dry. To prevent this from happening, after the air inside of the vehicle has cooled, turn the recirculation mode off.

The air conditioning system removes moisture from the air, so a small amount of water might drip under the vehicle while idling or after turning off the engine. This is normal.

(Outside Air): Press to turn the outside air mode on. An indicator light comes on to show that outside air is on. 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. Pressing this button will cancel the recirculation mode.

(Recirculation): Press to turn on the recirculation mode. An indicator light comes on to show that recirculation is on. This mode recirculates and helps to quickly cool or heat the air inside the vehicle. It can be used to prevent outside air and odors from entering the vehicle. Avoid using the recirculation mode during high periods of humidity and cool outside temperatures since this may result in increased window fogging. If window fogging is experienced, select the defrost mode. Recirculation mode is not available in floor, defog or defrost modes and will shut off automatically and change to outside air. The indicator will flash if the button is selected in any of these modes. This helps prevent window fogging and moisture building up inside the vehicle.

Rear Window Defogger

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

The rear window defogger only works when the ignition is in ON/RUN.

(Rear Window Defogger): Press to turn the rear window defogger on or off. An indicator light on the button comes on to show that the rear window is activated.

The rear window defogger stays on for approximately 10 minutes after the button is pressed, unless the ignition is turned to ACC/ACCESSORY or LOCK/OFF. If turned on again, the defogger only runs for approximately five minutes before turning off again. At higher vehicle speeds, the defogger may stay on continuously. The defogger can also be turned off by turning off the engine.

For vehicles with the remote start feature, the rear defogger will automatically turn on.

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

For vehicles with the remote start feature and if it is activated, the climate control system heats and cools the inside of the vehicle using the modes that were set before the vehicle was turned off and the rear defogger automatically turns on.