GM Service Manual Online
For 1990-2009 cars only

With this system you can control the heating, cooling and ventilation for your vehicle. If your vehicle has the remote start feature, the climate control system will function as part of the remote start feature. The system will return to the last settings the vehicle was at when it was turned off. See Remote Keyless Entry (RKE) System Operation .


Object Number: 918777  Size: B2

Operation

(Fan): Turn the left knob clockwise or counterclockwise to increase or decrease the fan speed. The fan must be on to run the air-conditioning compressor.

To change the air delivery settings, turn the right knob to 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, and the remaining air to the floor outlets. Some air may be directed toward the side windows.

(Floor): This mode directs most of the air to the floor outlets with some air directed to the side window outlets.

(Outside Air): Press the right side of this button to turn the outside air mode on. When this mode is selected, air from outside the vehicle will circulate throughout your vehicle. When the button is pressed, an indicator light will come on to let you know that it is activated. 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 the left side of the button to turn the recirculation mode on. When recirculation mode is selected, the air inside the vehicle will be recirculated through the climate control system and the vehicle, not from outside your vehicle. This mode is helpful when you are trying to limit odors from entering your vehicle and for maximum air conditioning performance in hot weather. When the button is pressed, an indicator light above the button will come on to let you know that it is activated. The recirculation indicator light will blink three times if you try to use recirculation in a mode that it can not be used in. Only use this mode when it is needed for comfort, since window fogging will rapidly occur if the air conditioning compressor is not engaged. Pressing this button will cancel the outside air mode. When you switch to the defog or defrost modes the system will automatically move from recirculation to outside air. When you move the mode knob back to another air delivery mode, the system will move back into recirculation. When the vehicle or fan is turned off and back on, the system will default to outside air automatically. Only use recirculation mode when it is needed for comfort, since window fogging may occur.

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

When it's cold outside 0°F (-18°C) or lower, use the engine coolant heater, if equipped, to provide warmer air faster to your vehicle. An engine coolant heater warms the coolant that the engine uses to provide heat to warm the inside of your vehicle. For more information, see Engine Coolant Heater .

(Air Conditioning): Press this button to turn the air conditioning system on or off. When the air conditioning button is pressed, an indicator light will come on to let you know that air conditioning is activated.

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.

For quick cool down on hot days, do the following:

  1. Select the vent mode.
  2. Select the highest fan speed.
  3. Select air conditioning.
  4. Select the recirculation mode.
  5. Select the coolest temperature.

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

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 (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 the defog or defrost mode.

(Defog): This mode splits the air between the windshield and the floor outlets with a small amount directed to the side windows. When you select this mode, the system turns off recirculation automatically. The air-conditioning compressor will run unless the outside temperature is at or below freezing. The air-conditioning compressor will operate although the indicator light will not be on. The air-conditioning indicator light will turn off when defog is selected. If the air-conditioning button is pressed while in defog mode, the indicator light will turn on. If the button is pressed again, the light will turn off. The recirculation mode cannot be selected while in the defog mode. Do not drive the vehicle until all the windows are clear.

(Defrost): This mode directs most of the air to the windshield with some air directed to the floor vents. In this mode, the system will automatically force outside air into your vehicle. The air-conditioning compressor will run unless the outside temperature is at or below freezing. The air-conditioning compressor will operate although the indicator light will not be on. The air-conditioning indicator light will turn off when defrost is selected. If the air-conditioning button is pressed while in defrost mode, the indicator light will turn on. If the button is pressed again, the light will turn off. Recirculation cannot be selected while in the defrost mode.

To help clear the windshield quickly, do the following:

  1. Select the defrost mode.
  2. Select the highest temperature.
  3. Select the highest fan speed.

Rear Window Defogger

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

REAR: Press this button to turn the rear window defogger on or off. An indicator light will come on to let you know that the rear window defogger is activated. Be sure to clear as much snow from the rear window as possible.

If driving below 50 mph (80 km/h), the rear window defogger will turn off about 15 minutes after the button is pressed. If turned on again, the defogger will only run for about seven 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's speed is maintained above 50 mph (80 km/h), the rear window defogger will remain on once the button is pressed.

If your vehicle has the remote start feature, the rear defogger will automatically be turned on if it is cold outside. The indicator light will be on. When the vehicle transitions out of the remote start mode, the rear defogger will turn off. See Remote Keyless Entry (RKE) System Operation .

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.

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

If your vehicle has the remote start feature and it is activated, the climate control system will automatically cool the vehicle if the temperature is greater than 90°F (32°C) and heat the vehicle if the temperature is below 37°F (3°C). If the temperature is between 37°F (3°C) and 90°F (32°C), the last control setting selected when the engine was running will be used. Normal operation and the last setting of the climate control system will return after the key is turned to the ON/RUN position.


Object Number: 1478826  Size: B2

Operation

OFF: Turn the left knob to this position to turn the climate control system off.

(Fan): Turn the knob by this symbol, located on the left side of the climate control panel, clockwise or counterclockwise to increase or decrease the fan speed. The fan speed will be temporarily reduced between the transition to a new mode. The fan will resume the original speed when the transition to the new mode is complete.

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

Use the right knob to select from the following modes:

(Vent): This mode directs outside air to the instrument panel outlets. If driving in city traffic, and the vehicle is stopped and idling, or the weather is hot, turning on the recirculation mode helps to prevent the air inside the vehicle from becoming stale. After five minutes recirculate will allow some outside air into the vehicle.

(Bi-Level): This mode directs half of the air to the instrument panel outlets, and the remaining air to the floor outlets. Some air may be directed toward the windshield. Slightly cooler air is directed to the instrument panel outlets and warmer air is directed to the floor outlets.

(Floor): This mode directs most of the air to the floor outlets with some air directed toward the side window outlets and a little air directed to the windshield. In this mode, the system will automatically use outside air. The air conditioning compressor will be engaged unless the outside temperature is 40°F (4°C) or below.

You can also select modes by using the following buttons:

(Recirculate): Press this button to recirculate cabin air through the vehicle. It can be used to help reduce the outside air and odors that enter your vehicle or to help heat or cool the air inside your vehicle quicker. An indicator light below the button will come on in this mode. Operation in this mode during periods of high humidity and cool outside temperatures may result in increased window fogging. If window fogging is experienced, select the defrost mode. To prevent the air inside the vehicle from becoming stale, after five minutes recirculate will allow some outside air into the vehicle.

(Air Conditioning): Press this button to turn the air conditioning system on or off. When this button is pressed, an indicator light below the button will come on to let you know the air conditioning is activated. Air conditioning can be selected in any mode as long as the fan switch is on. The indicator light will change with each button press even when conditions prevent operation.

On hot days during the vehicle's initial start-up, open the windows to let hot inside air escape; then close them. This helps to reduce the time it takes for the vehicle to cool down. It also helps the system to operate more efficiently.

For quicker cool down on hot days, do the following:

  1. Select the vent air mode.
  2. Select the recirculation mode.
  3. Select the air conditioner.
  4. Select the coolest temperature.
  5. Select the highest fan speed.

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.

Using these settings together for long periods of time may cause the air inside the vehicle to become too dry. To prevent this, after five minutes recirculate will allow some outside air into the vehicle.

Defogging and Defrosting

Fog on the inside of the vehicle is a result of high humidity causing moisture to condense on the cool window glass. This can be minimized if the climate control system is used properly. There are two modes to clear frost or fog from the windshield. Use the defog mode to clear the windows of condensation and to warm the vehicle's occupants. Use the defrost mode to remove frost or condensation from the windshield quickly.

See "Rear Window Defogger" later in this section for information on clearing the rear window of fog or ice.

Turn the right knob to select the defog or defrost mode.

Do not drive the vehicle until all windows are clear.

(Defog): This mode directs half of the air to the windshield and the side window outlets and half to the floor outlets. When you select this mode, the system turns recirculation off and runs the air conditioning compressor unless the outside temperature is near or below freezing. Pressing the recirculation button will have no effect other than turning on the indicator light while in defog mode.

(Defrost): This mode directs most of the air to the windshield and the side window outlets, with some air directed to the floor outlets. When you select this mode, the system turns recirculation off and runs the air conditioning compressor unless the outside temperature is near or below freezing. Pressing the recirculation button will have no effect other than turning on the indicator light while in defrost mode.

Rear Window Defogger

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

(Rear): Press the button to turn the rear window defogger on or off. An indicator light below the button will come on to let you know that the rear window defogger is activated.

The rear window defogger will only work when the ignition is in ON/RUN. The rear window defogger will stay on for about 20 minutes after the button is pressed. If turned on again, the defogger will only run for about 20 minutes before turning off. The defogger can also be turned off by pressing the button again or by turning off the engine.

The heated outside rearview mirrors, help to clear fog or frost from the surface of the mirror when the rear window defog button is pressed.

Do not drive the vehicle until all windows are clear.

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.