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: 928256  Size: B2

When your vehicle is first started, the system will recall the last temperature fan and mode settings for that driver.

Automatic Operation

AUTO (Automatic): When this button is pressed and the temperature is set, the system will automatically control the inside temperature, the air delivery mode, the air-conditioning compressor and the fan speed. AUTO will appear on the display.

  1. Press the AUTO button.
  2. Adjust the temperature to a comfortable setting between 70°F (21°C) and 80°F (27°C). An initial setting of 73°F (23°C) is suggested.
  3. Choosing the warmest or coldest temperature setting will not cause the system to heat or cool any faster. If you set the system at the warmest or coldest temperature setting, the system will remain in manual mode at that temperature and it will not go into automatic mode.

    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.

You can switch from English to metric units through the Driver Information Center (DIC). See DIC Controls and Displays for more information.

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.

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 "Sensors" later in this section.

Manual Operation

PWR (Power/Temperature): Press the PWR button on the left side of the climate control panel to turn the entire climate control system on or off. Press the up or down arrow on the switch to manually increase or decrease the temperature inside the vehicle. Press the PWR button on the right side of the climate control panel to turn the passenger's climate control system on or off. Press the up or down arrow on the switch to manually increase or decrease the temperature for the passenger. If the passenger's PWR button is off, the driver's temperature switch controls the temperature for the entire vehicle.

(Fan): Press this switch to increase or decrease the fan speed. Pressing this switch cancels automatic operation and places the system in manual mode. Press AUTO to return to automatic operation. 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 .

(Mode): Pressing the switch and changing the mode cancels automatic operation and places the system in manual mode. Press the AUTO button to return to automatic operation. To change the current mode, select one of the following:

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

(Bi-Level): This mode directs approximately half of the air to the instrument panel outlets, and then directs most of the remaining air to the floor outlets. In automatic operation, cooler air is directed to the upper outlets and warmer 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 outlets, and a little air directed to the windshield. The mode switch can also be used to select the defog mode. Information on defogging and defrosting can be found later in this section.

A/C OFF (Air Conditioning): Press this button to turn off the air conditioning compressor. Press AUTO to return to automatic operation. The compressor cannot be turned off in either the defrost or floor/defog mode.

(Heated/Cooled Seat): Press this button to turn the feature on. The button on the left controls the driver's seat and the button on the right controls the passenger's seat. Each press of the button will take you to a different setting. The settings available in order are HI HEAT, LO HEAT, OFF, HI COOL, LO COOL and OFF. You will be able to feel the temperature change in a few minutes. The feature will automatically turn off when the vehicle is turned off.

(Recirculation):  Press this button to turn the recirculation mode on or off. The air-conditioning compressor also comes on. 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 cool the air inside your vehicle more quickly. Recirculation is not available in defrost or floor/defog modes. Using recirculation for long periods of time may cause the air inside your vehicle to become too dry. To prevent this from happening, after the air in your vehicle has cooled, turn the recirculation mode off.

Sensors

There are sensors to measure the temperature and sun's effect on passenger comfort.

The solar sensor on your vehicle monitors the solar radiation then 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 maintain the temperature inside the vehicle. The outside temperature will be displayed in the navigation system only when the engine is running. Any cover on the front of the vehicle could give a false reading of the temperature.

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

    â€¢ The vehicle's speed is above 10 mph (16 km/h) for five minutes.
    â€¢ The vehicle's speed is above 32 mph (51 km/h) for two and one-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 button. 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 (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.

(Floor/Defog): Press the mode button until the defog mode appears on the display. This mode directs the air between the windshield, floor outlets and side windows. When you select this mode, the system turns off recirculation and runs the air-conditioning compressor unless the outside temperature is near or below freezing. The recirculation mode cannot be selected while in the floor/defog mode.

(Defrost): Press this button to direct most of the air to the windshield, with some air directed to the side windows. In this mode, the system will automatically turn off the recirculation and run the air-conditioning compressor, unless the outside temperature is near or below freezing. Recirculation cannot be selected while in the 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 or off. Be sure to clear as much snow from the rear window as possible.

The rear window defogger will turn off approximately 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 approximately five 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 will heat to help clear fog or frost from the surface of the mirrors when the rear window defogger is on.

The rear window defogger and heated mirrors are automatically disabled when the retractable hardtop 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.