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: 1556097  Size: B3

Operation

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

(Fan): Turn the left knob clockwise or counterclockwise to increase or decrease the fan speed. In any setting other than off, the fan will run continuously with the ignition on. To turn off the air completely, turn fan to 0 and select Recirculate.

Use the right knob to select from the following modes:

There are two minor detents between each mode to finely adjust airflow position.

(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 the remaining air 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 and side window outlets. Recirculation mode cannot be selected while in floor mode. This helps prevent window fogging and moisture building up within the cabin.

The right mode knob may also be used to select the defrost and defog modes that are described in this section.

You can also select modes by using the following buttons:

(Recirculate): Press this button on the center knob to recirculate cabin air through 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. An indicator light below the symbol will come on to let you know the recirculation mode is activated. Operation in this mode during periods of high humidity and cool outside temperatures may result in increased window fogging. If window fogging is experienced, select the defrost mode.

(Air Conditioning): Press this button to turn the air-conditioning system on or off. When this button is pressed, an indicator light on 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 switch 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 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 or frost 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. Use the defog mode to clear the windows of fog or moisture and warm the passengers. To avoid fogging windows on rainy and humid days at temperatures above freezing, run the air conditioning compressor. Also, it is best to avoid the use of recirculation mode except when maximum A/C performance is needed or for short times to avoid exterior odors. Use the defrost mode to remove fog or frost from the windshield more quickly. When you select either of these modes (or the floor mode which also helps defog the windows slightly), the system runs the air-conditioning and cancels recirculation mode to dry the air; however, the recirculation light will stay on. 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 half of the air to the windshield, the side window outlets and to the floor outlets. When this 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. Recirculation mode cannot be selected while in defog mode; however, the recirculation light will stay on. It is best to avoid the use of recirculation mode except when maximum A/C performance is needed or for short times to avoid exterior odors.

(Defrost): This mode directs most of the air to the windshield and the side window outlets, with some air directed to the floor outlets. When this mode is selected, 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 the defrost mode; however, the recirculation light will stay on. 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): Press this button to turn the rear window defogger on or off. An indicator light on the button will come on to let you know that the rear window defogger is activated.

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