GM Service Manual Online
For 1990-2009 cars only

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


Object Number: 1574026  Size: B2

Operation

To change the current mode, use the right knob to select one of the following:

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

(Bi-Level): This mode directs air to the instrument panel outlets and to the floor outlets. 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 windshield. When the floor mode is selected, the system will turn recirculation mode off and run the air conditioning compressor unless the outside air is at or below freezing. Entering this mode may force the engine into the start/stop mode. See "Air Conditioning and Engine Start/Stop" later in this section. Recirculation mode cannot be selected while in floor mode. This helps prevent window fogging and moisture building up within the cabin.

The right knob can also be used to select defog or defrost mode. See "Defogging and Defrosting" later in this section.

(Fan): Turn the left knob clockwise to increase the fan speed or counterclockwise to decrease the fan speed. To turn the fan off, turn the left knob all the way counterclockwise. In any setting other than off, the fan will run continuously with the ignition on. The fan must be turned on to run the air conditioning compressor. There will be some airflow noticeable from the various outlets when driving, even with the fan in the off position. This is to ensure some fresh air is always available in the vehicle. Turning the fan from off to on may force the engine into the start/stop mode. See "Air Conditioning and Engine Start/Stop" later in this section.

Temperature Control: Turn the center knob clockwise to increase or counterclockwise to decrease the temperature inside your vehicle.

(Recirculate): Press this button to toggle between recirculate and outside air modes. The indicator light turns on when the recirculate mode is selected. This mode 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. Avoid using the recirculate mode during high periods of humidity or cool outside temperatures since this may result in increased window fogging. If window fogging is experienced, select the defrost mode. Recirculation mode is not available in floor, defog, or defrost modes and will shut off automatically and change to outside air until a mode other than floor, defog, or defrost is selected. This helps prevent window fogging and moisture building up within the cabin.

(Air Conditioning): Press this button to change the air conditioning mode between economy, normal, and off. When this button is pressed the indicator light will change with each mode. The green indicator light comes on when economy mode is selected. The yellow indicator light comes on when normal mode is selected. Turning the air conditioning on may force the engine into the start/stop mode. See "Air Conditioning and Engine Start/Stop" later in this section. Air conditioning can be selected in any mode as long as the fan is on.

On hot days, activate the air conditioning system, select maximum fan speed and the coldest temperature setting. Open the windows long enough to let the hot inside air escape, then close them. This helps reduce the time it takes for the vehicle to cool down. It also helps the system to operate more efficiently. Adjust fan speed and temperature setting as required to achieve comfort.

The air conditioning system removes moisture from the air, so you may sometimes notice a small amount of water dripping underneath the vehicle while idling or after turning off the engine. This is normal.

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 and side windows. Use the defog 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.

Turn the right knob to select the defog or defrost mode.

(Defog): This mode directs air to the windshield, side window outlets and floor outlets. When this mode is selected, the system will turn the recirculation mode off and run the air conditioning compressor unless the outside air is at or below freezing. The recirculation mode cannot be selected while in defog mode. This helps prevent window fogging and moisture building up within the cabin. To defog the windows faster, turn the temperature knob clockwise to the warmest setting. Using the defog mode may force the engine into the start/stop mode. See "Air Conditioning and Engine Start/Stop" later in this section.

(Defrost): This mode directs most of the air to the windshield, with some air directed to the side window outlets and the floor outlets. When you select this mode, the system will turn recirculation mode off automatically and will run the air conditioning compressor unless the outside air is at or below freezing. The recirculation mode cannot be selected while in defrost mode. This helps prevent window fogging and moisture building up within the cabin. To defrost the windows faster, turn the temperature knob clockwise to the warmest setting. Using the defrost mode may force the engine into the start/stop mode. See "Air Conditioning and Engine Start/Stop" later in this section.

Rear Window Defogger

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

The rear window defogger will only work when the ignition is in RUN.

(Rear Window Defogger): Press the button to turn the rear window defogger on or off. An indicator light above the button will come on to show that the rear window defogger is activated.

The rear window defogger will stay on for approximately 15 minutes after the button is pressed, unless the ignition is turned to ACC or LOCK. If turned on again, the defogger will only run for approximately seven minutes before turning off. The defogger can also be turned off by pressing the button again or by turning off the engine.

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.

Air Conditioning and Engine Start/Stop


Object Number: 1749884  Size: B1

The climate control system might cause the engine to keep running while the vehicle is at a complete stop or it might restart the engine during an auto stop. In cold weather, the climate control system uses the automatic engine start/stop feature to maintain heater and defogging performance in all air flow modes.

Economy Mode: Press the button once to select the economy mode. A green indicator light will appear. When this mode is selected, the climate control system allows almost all automatic engine start/stop operations, except in defrost mode.

If the economy mode is selected while the engine is off, the engine will start while the vehicle determines the climate control needs. If the system determines that it is necessary to turn on the air conditioning compressor to cool the inside of the vehicle or dehumidify the air, the automatic engine start/stop feature might still be enabled.

Normal Mode: Press the button, when a yellow indicator light appears, the normal mode is selected. In this mode or the defrost mode, the climate control system prevents all automatic engine start/stop operations. This is for the best comfort and defrost performance.

For maximum engine off time, select the vent or bi-level modes with the air conditioner turned off. This will prevent the system from overriding the automatic engine start/stop feature. Setting the fan to the off position will also prevent automatic engine start/stop.

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


Object Number: 1574026  Size: B2

Operation

To change the current mode, use the right knob to select one of the following:

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

(Bi-Level): This mode directs air to the instrument panel outlets and to the floor outlets. 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 windshield. When you select this mode, the system will turn recirculation mode off and run the air conditioning compressor unless the outside air is at or below freezing. Recirculation mode cannot be selected while in floor mode. This helps prevent window fogging and moisture building up within the cabin.

The right knob can also be used to select defog or defrost mode. See "Defogging and Defrosting" later in this section.

(Fan): Turn the left knob clockwise to increase the fan speed or counterclockwise to decrease the fan speed. To turn the fan off, turn the left knob all the way counterclockwise. In any setting other than off, the fan will run continuously with the ignition on. The fan must be turned on to run the air conditioning compressor. There will be some airflow noticeable from the various outlets when driving, even with the fan in the off position. This is to ensure some fresh air is always available in the vehicle.

Temperature Control: Turn the center knob clockwise to increase or counterclockwise to decrease the temperature inside your vehicle.

(Recirculate): Press this button to toggle between recirculate and outside air modes. The indicator light turns on when recirculate mode is selected. This mode 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. Avoid using the recirculate mode on during high periods of humidity or cool outside temperatures since this may result in increased window fogging. If window fogging is experienced, select the defrost mode. Recirculation mode is not available in floor, defog, or defrost modes and will shut off automatically and change to outside air until a mode other than floor, defog, or defrost is selected. This helps prevent window fogging and moisture building up within the cabin.

(Air Conditioning): Press this button to turn the air conditioning system on or off. When this button is pressed, an indicator light above the button will come on to let you know the air conditioning is activated. Air conditioning can be selected in any mode as long as the fan is on in any speed position.

On hot days, activate the air conditioning system, select maximum fan speed and the coldest temperature setting. Open the windows long enough to let the hot inside air escape, then close them. This helps reduce the time it takes for your vehicle to cool down. It also helps the system to operate more efficiently. Adjust fan speed and temperature setting as required to achieve comfort.

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.

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 and side windows. Use the defog 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.

Turn the right knob to select the defog or defrost mode.

(Defog): This mode directs air to the windshield, side window outlets and floor outlets. When you select this mode, the system will turn recirculation mode off and run the air conditioning compressor unless the outside air is at or below freezing. Recirculation mode cannot be selected while in defog mode. This helps prevent window fogging and moisture building up within the cabin. To defog the windows faster, turn the temperature knob clockwise to the warmest setting.

(Defrost): This mode directs most of the air to the windshield, with some air directed to the side window outlets and the floor outlets. When you select this mode, the system will turn recirculation mode off automatically and will run the air conditioning compressor unless the outside air is at or below freezing. Recirculation mode cannot be selected while in defrost mode. This helps prevent window fogging and moisture building up within the cabin. To defrost the windows faster, turn the temperature knob clockwise to the warmest setting.

Rear Window Defogger

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

The rear window defogger will only work when the ignition is in RUN.

(Rear Window Defogger): Press the button to turn the rear window defogger on or off. An indicator light above the button will come on to let you know that the rear window defogger is activated.

The rear window defogger will stay on for approximately 15 minutes after the button is pressed, unless the ignition is turned to ACC or LOCK. If turned on again, the defogger will only run for approximately seven minutes before turning off. The defogger can also be turned off by pressing the button again or by turning off the engine.

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.