GM Service Manual Online
For 1990-2009 cars only

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

If your vehicle has the remote start feature and it is activated, the climate control system will heat and cool the inside of the vehicle, using the previous system settings before the vehicle was turned off. The heated seats, if the vehicle has them, and the rear window defogger will be turned on by the climate control system when it is cold outside. Cooled seats are not activated during a remote start. Normal operation of the system will return after the key is turned to the RUN position. See Remote Keyless Entry (RKE) System Operation for more information.


Object Number: 1670859  Size: B1

Operation

(Off): Turn the left knob to this position to turn the climate control system off. Outside air still enters the vehicle and is directed to the floor. The airflow direction and temperature can be adjusted, as indicated below.

(Fan): Turn the left knob clockwise or counterclockwise to increase or decrease the fan speed. The fan speed is temporarily reduced between the transition to a new mode. The fan will resume when the new mode is complete. If the airflow seems low when the fan speed is at the highest setting, the passenger compartment air filter may need to be replaced. For more information, see Passenger Compartment Air Filter and Scheduled Maintenance .

Temperature Control: Turn the center knob clockwise or counterclockwise to warm or cool the air coming through the outlets.

Mode Control: Use the right knob to select the airflow direction.

(Vent): This mode directs outside air to the instrument panel outlets.

(Bi-Level): This mode splits the air between the instrument panel outlets and the floor outlets. Slightly cooler air is directed to the instrument panel outlets and warmer air is directed to the floor outlets.

(Floor): This mode automatically uses outside air and directs most to the floor outlets . Some air is directed toward the side window outlets and to the windshield. If recirculation is selected while in this mode, it stays on for three minutes to reduce windshield fogging.

Additional modes can be selected by using the following buttons:

(Recirculation): Press this button to recirculate cabin air through the vehicle. An indicator light below the button comes on to show that this mode is activated. This mode can be used to prevent outside air and odors from entering the vehicle or to help cool the air inside the vehicle more quickly. This mode cannot be selected while in the defog or defrost modes. If you try to select the recirculation mode, the indicator light flashes three times and turns off. 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.

(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 comes on to show that this mode is activated. Air conditioning can be selected in any mode as long as the fan knob is not in the off position.

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 a small amount of water may drip underneath the vehicle while idling or after turning off the engine. This is normal.

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 floor/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. The recirculation mode cannot be selected while in these modes.

(Floor/Defog): This mode directs half of the air to the windshield and the side window outlets and half to the floor outlets. The system runs the air conditioning compressor unless the outside temperature is near or below freezing.

(Defrost): This mode directs most of the air to the windshield and the side window outlets. The system runs the air conditioning compressor unless the outside temperature is near or below freezing.

Rear Window Defogger

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

(Rear Window Defogger): Press this button to turn the rear window defogger on or off. An indicator light below the button comes 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. The rear window defogger will only work when the ignition is in run. The rear window defogger stays on for about 20 minutes after the button is pressed if you are traveling at slower vehicle speeds. At higher vehicle speeds, the rear defogger may stay on continuously. If turned on again, the defogger only runs for about 10 minutes before turning off. The defogger can be turned off by pressing the button again, by turning the ignition to ACCESSORY or RUN, or by turning off the engine. If your vehicle has heated outside rearview mirrors, the mirrors heat to help clear fog or frost from the surface of the mirror when the rear window defogger is on. See Outside Automatic Dimming Heated Mirror for more information.

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.