Air Distribution: Notes
WARNING: This page is about a different car, the 2003 Buick Regal and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
The operator uses the mode switch on the HVAC control module to change the air delivery mode in the vehicle. The HVAC control module communicates the mode door position to the vacuum control assembly through five solenoid control circuits.