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: 811231  Size: B2

Turn the right knob clockwise or counterclockwise to direct the airflow inside of your vehicle.

To change the current mode, select one of the following:

(Bi-Level): This mode directs approximately half of the air to the instrument panel outlets and directs most of the remaining air to the floor outlets. Some air may be directed toward the windshield.

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

(Floor): This mode directs most of the air to the floor outlets with some air directed to the outboard outlets (for the side windows) and some air directed to the windshield.

A/C (Air Conditioning):  This setting brings in outside air, cools and dehumidifies it.

MAX A/C (Maximum Air Conditioning):  This setting cools the air the fastest, by recirculating the inside air. The right knob can also be used to select the defrost mode. Information on defogging and defrosting can be found later in this section.

(Fan): Turn the left knob clockwise or counterclockwise to increase or decrease the fan speed.

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

Defogging and Defrosting

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

(Blend): With this setting, the outside air comes out of both the floor and defroster outlets. Adjust the temperature knob for warmer or cooler air. The air conditioning compressor may operate in this setting to dehumidfy the air.

(Defrost): This setting operates the defroster. Most of the air comes out near the windshield, with some going to the floor outlets and front side windows. The air conditioning compressor may operate in this setting to dehumidify the air.

The bi-level setting is useful for cold weather with a large number of passengers or very humid conditions to help keep the windshield clear. Use defrost to remove fog or ice from the windshield quickly in extremely cold conditions. The temperature knob should be in the red area and the fan control toward high.