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: 1462625  Size: B2

When the vehicle is first started, the display will show the driver's temperature setting, the outside temperature, the fan speed and the air delivery, for about 10 seconds.

The outside temperature is shown in the center of the display. The digital display will show the readings in Fahrenheit or Celsius. See "Personal Options" under DIC Vehicle Personalization for information on changing your display.

Automatic Operation

AUTO (Automatic): Press the AUTO button to place the entire system in the automatic mode. When automatic operation is active, the system will automatically control the inside temperature, the air delivery mode, and the fan speed.

After a ten second display of the current settings, the word AUTO, the driver's temperature setting and the outside temperature will be shown. The system will operate to achieve your comfort set temperature as quickly as possible. The AUTO control system works best with the windows up and the removable roof installed or the convertible top up.

  1. Press the AUTO button.
  2. Adjust the temperature to a comfortable setting between 60°F (16°C) and 90°F (32°C). Choosing the coldest or warmest temperature setting will not cause the system to heat or cool any faster. A setting of 73°F (23°C) is suggested.
  3. 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.

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 "Sensor" later in this section.

Manual Operation

Driver Power/Temperature: Press the driver temperature knob on the driver side of the climate control panel to turn the climate control system off. This is the only setting that completely shuts off the fan. The digital display will show only the outside temperature. You can still adjust the driver and the passenger set temperature and the air intake mode when the climate control is off.

Passenger Power/Temperature: Press the passenger temperature knob on the passenger side of the climate control panel to turn the passenger's climate control system on or off. Turn the knob to increase or decrease the temperature for the passenger. If the passenger's climate control system is off, the driver's temperature knob will control the temperature for the entire vehicle.

(MODE): Press this button to manually lock in the current air delivery setting and to stop the automatic mode control. Pressing the MODE button will delete AUTO from the digital display and the mode graphics will be shown. To change the setting, press the MODE button again. The AUTO button must be pressed to return to the automatic mode selection. To change the current mode, select one of the following:

(Vent): This mode directs most of the air to the instrument panel outlets, with a very small amount of air directed to the floor outlets.

(Bi-Level): This mode directs about half of the air to the instrument panel outlets, and directs the remaining air to the floor outlets.

(Floor): This mode directs most of the air to the floor outlets with some air directed to the side window defogger outlets and some air directed toward the windshield. The MODE button can also be used to select the defog mode. Information on defogging and defrosting can be found later in this section.

(Fan): Press the button with the fan symbol to manually increase or decrease the fan speed. Keep pressing the up or down arrow on this switch until the desired fan speed appears on the display. Pressing the arrows will delete AUTO from the digital display. The fan graphics with the fan speed bars will be shown. To increase the fan speed so that more air flows into the vehicle, press the up arrow on the fan switch. To decrease the fan speed and airflow, press the down arrow. The AUTO button must be pressed to return to the automatic fan control. 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 .

(Recirculation): Press this button to turn the recirculation mode on or off. When the climate control system is in recirculation mode an indicator light will come on. This mode prevents outside air from entering your vehicle. It can be used to prevent outside air and odors from entering your vehicle and to help cool the air inside your vehicle more quickly. Recirculation mode is not available in defrost or defog mode.

(Air Conditioning Off): Press this button to turn the air conditioning compressor off. Press AUTO to return to automatic operation. When in AUTO, the air conditioning compressor will come on automatically, as needed. Air conditioning does not operate at temperatures below about 35°F to 40°F (2°C to 4°C). In temperatures above 40°F (4°C), the air conditioning cannot be turned off in defrost and defog, as it helps to remove moisture from the vehicle. It also helps to keep the windows clear.

You may notice a slight change in engine performance when the air-conditioning compressor shuts off and turns on again. This is normal. The system is designed to make adjustments to help with fuel economy while still maintaining the selected temperature.

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 press the AUTO button and adjust the temperature to a cool, comfortable setting. To achieve maximum cool down, do the following:

  1. Select the vent mode.
  2. Select recirculation mode.
  3. Select the A/C on.
  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 uses the information to maintain the selected temperature when operating in AUTO mode 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 on the top of the instrument panel near the windshield or the system will not work properly.

There is also a sensor located behind the front bumper. This sensor reads the outside air temperature and helps to maintain the temperature inside the vehicle. Any cover on the front of the vehicle could give a false reading in the temperature.

If the outside temperature goes up, the displayed temperature will not change until:

    • The vehicle's speed is above 12 mph (19 km/h) for five minutes.
    • The vehicle's speed is above 32 mph (52 km/h) for two and a half minutes.

These delays prevent false readings. If the temperature goes down, the outside temperature will be shown when you start the vehicle. If it has been turned off for less than three hours, the temperature will be recalled from the previous vehicle operation.

There is also an inside temperature sensor located to the left of the ignition switch. The automatic climate control system uses this sensor to receive information, so if you block or cover it, the system will not function properly.

Defogging and Defrosting

Fog on the inside of windows is a result of high humidity and 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. Use the floor/defog mode to clear the windows of fog or moisture and warm the passengers. Use defrost to remove fog or frost from the windshield more quickly. To prevent fogging on the inside of the windows in modes other than floor/defog and defrost, make sure the air conditioning compressor is on and recirculation mode is off.

Press the mode button until the defog mode appears on the display.

(Floor/Defog): This mode directs the air equally between the windshield and the floor outlets with a small amount to the side window outlets. When you select this mode, the system turns off recirculation and runs the air-conditioning compressor unless the outside temperature is at or below freezing. The recirculation mode cannot be selected while in the defog mode.

(Defrost): Pressing this button directs most of the air to the windshield, with a small amount directed to the side window outlets. The light on the button will come on and the digital display will show the defrost mode symbol and fan speed when the front defrost mode is being used. In this mode, the system will automatically turn off the recirculation and run the air-conditioning compressor, unless the outside temperature is at or below freezing. Recirculation cannot be selected while in the defrost mode. Pressing this button again will return the system to the last operating mode. For severe ice conditions, turn the driver's temperature knob to 90°F (32°C) while in 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.

The rear window defogger will only work when the engine is running.

(Rear Window Defogger): Press this button to turn the rear window defogger on. Be sure to clear as much snow from the rear window as possible. An indicator light in the button will come on to let you know that the rear window defogger is activated.

The rear window defogger will turn off about 10 minutes after the button is pressed when traveling less than 30 mph (48 km/h). If turned on again, the defogger will only run for about five minutes before turning off. The defogger can also be turned off by pressing the button again or by turning off the engine.

Your vehicle has heated outside rearview mirrors. The mirrors will heat to help clear fog or frost from the surface of the mirrors when the rear window defog button is pressed.

If your vehicle has the power convertible top, the rear window defogger and heated mirrors are automatically disabled when the power convertible top is moving or down.

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.