GM Service Manual Online
For 1990-2009 cars only

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


Object Number: 810714  Size: B1
TEMPERATURE: This lever is used to adjust the temperature of the air coming through the system. Moving the lever between COOL and WARM will change the temperature of the air coming through your outlets.

FAN: Move this lever to select the speed of the fan. Moving the lever between LOW and HIGH will decrease or increase the fan speed. The fan will be off when the system is off.

To change the current mode, select one of the following:

RECIRC (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 to 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. You cannot use RECIRC with FRONT Defrost or BLEND.

VENT: This mode directs air to the instrument panel outlets.

HTR (Heater): This mode directs most of the air to the floor outlets with some air directed to the outboard outlets (for the side windows) and some air directed to the windshield.

BLEND: This mode splits the airflow between the windshield and the floor outlets. The air conditioning compressor will be operating.

OFF: The ventilation system always allows fresh air to flow through your vehicle when it is moving. The system will try to keep the air at a previously chosen temperature. When the system is off, the blower fan is also off.

MAX (Maximum Air Conditioning): This mode directs airflow through the instrument panel outlets. The amount of outside air entering your vehicle is limited. Also in this mode, the RECIRC function is activated to create the maximum cooling effect in the vehicle. If RECIRC was activated before selecting MAX, the light in the RECIRC button will go off. If RECIRC is selected after MAX, the light in the RECIRC button will not come on.

NORM (Normal Air Conditioning): This mode cools the outside air entering your vehicle and directs it through the instrument panel outlets.

BI-LEV (Bi-Level Air Conditioning): This mode directs about half of the air to the instrument panel outlets, and then directs most of the remaining air to the floor outlets. Some air may be directed toward the windshield. Cooler air is directed to the upper outlets and warmer air to the floor outlets. The air conditioning compressor is on in this mode.

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 RECIRC mode.
  3. Select MAX.
  4. Select the coolest temperature.
  5. Select the highest fan speed.

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.

Sensors

The solar sensor on your vehicle monitors the solar radiation and the air inside of your vehicle. This information is then used to maintain the selected temperature by initiating needed adjustments to the temperature, the fan speed, and the air delivery system. The system may also supply cooler air to the side of the vehicle facing the sun. The recirculation mode will also be activated, as necessary. Do not cover the solar sensor located in the center of the instrument panel, near the windshield, or the system will not work properly.

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. This mode allows you to clear fog or frost from your windshield.

FRONT (Defrost): Pressing this button directs most of the air to the windshield and the outboard outlets (for the side windows), with some air directed to the floor outlets. In this mode, the system will automatically turn off recirculation and run the air conditioning compressor, unless the outside temperature is at or below freezing. Recirculation cannot be selected while in FRONT 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 or frost from the rear window.

REAR (Rear Window Defogger): Press this button to turn the rear window defogger on or off. Be sure to clear as much snow from the rear window as possible. At speeds above 35 mph (55 km/h), the defogger will operate continuously until you press the REAR button again. After 10 minutes of driving below 35 mph (55 km/h), the defogger will turn off automatically. If you need additional warming time, push the button again. The system will then operate for five minutes before going off by itself. 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 defogger button is pressed.

Notice: Do not use a razor blade or sharp object to clear the inside rear window. Do not adhere anything to the defogger grid lines in the rear glass. These actions may damage the rear defogger. Repairs would not be covered by your warranty.