HVAC Control Module Replacement
WARNING: This page is about a different car, the 2007 Chevrolet Monte Carlo and 2007 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
If the HVAC Control Module is replaced, the following procedure must be performed: Reprogram the HVAC Control Module. Refer to Re-Calibrating Actuators