Air Distribution

WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The HVAC control module controls the mode actuator in order to distribute airflow to a desired outlet. The mode switch provides the vehicle operator with the ability to override the automatic setting. When the mode door is moved to the defrost position, the A/C compressor clutch engages and the recirculation actuator will be moved to the outside air position. Regardless of the mode setting, a small amount of air will be diverted to the defrost ducts to reduce windshield fogging. This vehicle may be equipped with a passenger compartment air filter. When VENT is pressed, the following will occur:

The recirculation actuator will be placed in the outside air position
The A/C compressor will be commanded off
The mode is adjustable

After a malfunction occurs to the mode actuator it is driven to the Defrost position. On start-up, the HVAC control module will place the mode door in the last selected position.