Possible Causes
WARNING: This page is about a different car, the 2005 Dodge Stratus and 2005 Chrysler Sebring. However, it is still accessible from the selected car via links, so may be relevant.
CONTROL HEAD - A/C MODE SWITCH MUX SHORTED TO VOLTAGE
A/C MODE SWITCH MUX CIRCUIT SHORTED TO VOLTAGE
BODY CONTROL MODULE - A/C MODE SWITCH MUX SHORTED TO VOLTAGE