GM Service Manual Online
For 1990-2009 cars only

The heating, cooling, and ventilation in the vehicle can be controlled with this system.


Object Number: 2042082  Size: G3
  1. Fan Control

  2. Temperature Control

  3. Air Delivery Mode Control

  4. Air Conditioning

  5. REAR (Rear Climate Control)

  6. Recirculation

  7. Rear Window Defogger

(Off): Turn the fan control all the way counterclockwise to turn the front climate control system off.

(Fan Control):  Turn clockwise or counterclockwise to increase or decrease the fan speed.

Temperature Control:  Turn clockwise or counterclockwise to increase or decrease the temperature of the air flowing from the system.

Air Delivery Mode Control: Turn clockwise or counterclockwise to change the current airflow mode. By positioning the right knob between two modes, a combination of those two modes is selected.

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

(Bi-Level):  Air is divided between the instrument panel and floor outlets. Some air is directed towards the windshield and side window outlets. Cooler air is directed to the upper outlets and warmer air to the floor outlets.

(Floor): Air is directed to the floor outlets, with some of the air directed to the windshield, side window, and second row floor outlets. In this mode, the system automatically selects outside air. Recirculation cannot be selected while in floor mode.

(Defog):  This mode clears the windows of fog or moisture. Air is directed to the windshield, floor outlets, and side window vents. When this mode is selected, the system turns off recirculation and runs the air conditioning unless the outside temperature is less than 40°F (4°C). Recirculation cannot be selected while in the defog mode. Do not drive the vehicle until all the windows are clear.

(Defrost): This mode quickly clears the windshield of fog or frost. Air is directed to the windshield and side window vents, with some to the floor vents. In this mode, outside air is pulled inside the vehicle. Recirculation cannot be selected while in the defrost mode. The air conditioning system runs automatically in this setting, unless the outside temperature is less than 40°F (4°C). Do not drive the vehicle until all the windows are clear.

(Air Conditioning):  Press to turn the air conditioning system on or off. An indicator light comes on when A/C is on. The air conditioning system does not operate when the outside temperature is below 40°F (4°C). The indicator light flashes three times and turns off when outside conditions affect air conditioning operation. This is normal.

For quicker cool down on hot days:

  1. Open the windows to let hot air escape.
  2. Select mode.
  3. Select .
  4. Select the coolest temperature.
  5. Select the highest fan speed.
  6. Close the windows after the hot air has escaped.
  7. Once the vehicle's interior temperature is below the outside temperature, select mode for faster cooling.

Using recirculation for long periods of time could cause the air inside of the vehicle to become too dry. To prevent this from happening, after the 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.

(Recirculation): Press to turn the recirculation mode on or off. An indicator light comes on when recirculation is on. When the engine is turned off, the recirculation mode automatically turns off and must be re-selected when the engine is turned on again. This mode recirculates and helps to quickly cool the air inside the vehicle. It can be used to prevent outside air and odors from entering the vehicle. The recirculation mode cannot be used with floor, defrost, or defogging modes. If recirculation is selected in these modes, the indicator flashes three times and turns off. The air conditioning also comes on when this mode is activated unless the outside air temperature is less than 40°F (4°C). While in recirculation mode the windows can fog when the weather is cold and damp. To clear the fog, select either the defog or defrost mode and increase the fan speed.

REAR (Rear Climate Control): Press to turn the rear heating and air conditioning on or off. See Rear Air Conditioning and Heating System or Rear Air Conditioning and Heating System and Electronic Climate Controls.

Rear Window Defogger

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

(Rear Window Defogger): Press to turn the rear window defogger on or off. The rear window defogger stays on for about 10 minutes, before automatically turning off. The defogger will also turn off when the engine is turned off. Do not drive the vehicle until all the windows are clear.

For vehicles with heated outside rearview mirrors, fog or frost is cleared from the surface of the mirror when 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.