Air Distribution
WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The HVAC control module controls the mode actuators in order to distribute airflow to a desired outlet. When the mode door is moved to the mix-blend or 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. On startup, the HVAC control module will place the mode door in the last selected position.