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: 809872  Size: B2

Automatic Operation

AUTO (Automatic): Press the AUTO button for automatic control of the inside temperature, the air delivery mode and the fan speed. You may notice a delay of two to three minutes before the fan comes on when the automatic operation is used in cold weather. For the automatic system to function, the temperature must be set between 61°F (16°C) and 89°F (31°C).

  1. Adjust the temperature to a comfortable setting.
  2. Press the AUTO button.
  3. Choosing the coldest or warmest temperature setting will not cause the system to heat or cool any faster.

    If you set the system at the warmest temperature setting, 90°F (32°C), hot air will be directed to the floor, the fan will increase to the highest speed, and, the system will remain in manual mode at that temperature. The system will not return to automatic until the temperature setting is lowered.

    If you set the system at the coldest temperature setting, 60°F (15°C), cold interior air will be recirculated through the air panel outlets, and the fan will increase to the highest speed. The system will not return to automatic until the temperature is raised.

    In cold weather, the system will start at reduced fan speeds to avoid blowing cold air into your vehicle until warmer air is available. The system will start out blowing air at the floor but may change modes automatically as the vehicle warms up to maintain the chosen temperature setting. The length of time needed for warm up will depend on the outside temperature and the length of time that has elapsed since your vehicle was last driven.

  4. Wait for the system to regulate. This may take from 10 to 30 minutes. Then, adjust the temperature, if necessary.
  5. Do not cover the solar sensor located in the center of the instrument panel, near the windshield. For more information on the solar sensor, see "Solar Sensor" later in this section.

Manual Operation

During daylight hours, you may want to adjust the instrument panel brightness control to the highest setting in order to see the indicator lights that go on for the various climate control settings.

OFF: Pressing the OFF button cancels automatic operation and places the system in manual mode. Press the AUTO button to return to automatic operation.

TEMP (Temperature): To manually adjust the temperature inside the vehicle, press the up arrow on the TEMP control to raise the temperature and press the down arrow to lower the temperature. The display will show your selection for a few seconds, and then the outside temperature will be displayed. When the DUAL light indicator is on, this means the TEMP control has set the temperature for the driver. When the DUAL light indicator light is not on, this means the TEMP control has set the temperature for the entire cabin.

FAN: Press the up arrow on the FAN control to increase fan speed and the down arrow to decrease fan speed. Pressing the arrows cancels the automatic operation and places the system in manual mode. Press the AUTO button to return to automatic operation. If the airflow seems low when the fan is at the highest setting, the passenger compartment air filter, if equipped, may need to be replaced. For more information see Passenger Compartment Air Filter and Part A: Scheduled Maintenance Services .

AIR FLOW: This control has several setting to control the direction of airflow when the system is not in AUTO. To access the various modes available, continue to press the AIR FLOW up or down arrows until the desired mode, (listed below), appears in the display.

WINDSHIELD/FLOOR: This setting directs some of the air to the floor outlets and some to the defroster and side window outlets. The air-conditioning compressor will run automatically in this setting unless the outside temperature is below 40°F (4°C).

MID/FLOOR: This mode directs airflow through both the floor and the instrument panel outlets. A small amount of air is directed to the windshield and the side window outlets.

MID (Instrument Panel): This mode directs air through the instrument panel outlets.

FLOOR: This setting sends most of the air through the outlets near the floor. The rest comes out of the defroster and side window outlets.

VENT: Press this button to turn the air-conditioning compressor on or off. The indicator light on the VENT mode is lit when the compressor is turned off. You may have to adjust the interior brightness control to the highest setting during the day in order to see the indicator lamp. VENT does not operate in the FRONT defrost mode.

RECIRC (Recirculation): Press this button to turn this mode on or off. RECIRC limits the amount of outside air coming into the vehicle and recirculates most of the air inside your vehicle. It can be use to prevent outside air and odors from entering your vehicle or to quickly heat or cool the air inside your vehicle. When this button is pressed an indicator light will come on. You may have to adjust the interior brightness control to the highest setting during the day in order to see the indicator lamp. This setting is not permitted in FRONT defrost mode and is only permitted in WINDSHIELD/FLOOR mode if the compressor is turned on. On hot days, open the window 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, press the AUTO button and the system will automatically enter the recirculation mode and the temperature will be at the full cold position for maximum cooling. 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. Operating the climate control system in the RECIRC mode may cause fogging of the vehicle's windows when the weather is cold and damp. To clear the fog, select either WINDSHIELD/FLOOR or defrost mode and increase the speed.

Sensors

The solar sensor on your vehicle monitors the solar radiation and the air inside of your vehicle, then uses the information 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.

Passenger Control

The arrow buttons to control the temperature on the passenger side of the vehicle are located to the right of the PASSENGER CONTROL window. Press the DUAL button so that the indicator light is on. Press the right arrow to raise the temperature and press the left arrow to lower the temperature on the passenger side of the vehicle.

    • If the indicator light below the arrows is amber this indicates that the passenger side temperature is set the same as the driver's side.
    • If the indicator light below the arrows is red, this indicates that the passenger side temperature is set warmer than that of the driver's side.
    • If the indicator light below the arrows is blue this indicates that the passenger side temperature is set cooler than that of the driver's side.

Defogging and Defrosting

Fog on the outside of the 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 clear fog or frost from your windshield and side windows. Use the WINDSHIELD/FLOOR 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. For best results, clear all snow and ice from the windshield before defrosting.

FRONT (Defrost): This setting brings in outside air and directs most of the air through the defrost outlet. Some of the air also goes to the floor vents and the side window outlets. The indicator light on the button will come on and WINDSHIELD will be seen on the display To defrost the windows quickly, press the FRONT button, set the temperature to 90°F (32°C), select a high fan speed and turn the DUAL button off. To warm passengers while keeping the window clear, push the AIR FLOW button to select WINDSHIELD/FLOOR which will appear on the display. Select a fan speed. The air-conditioning compressor will run automatically in this setting unless the outside temperature is below 40°F (4°C). Do not drive the vehicle until all windows are clear.

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. It will turn off after about 15 minutes. If you turn it on again, the rear defogger will only run for about seven and one half minutes before turning off. You can also turn it off by pressing the button again. Do not drive the vehicle until all the windows are clear.

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.