System Operation - Exterior, Heated

The rear window defrost switch controls operation of the heated exterior mirror glass (if equipped). The heated exterior mirror glass only operates when the rear window defrost system is active. For a detailed description of the rear window defrost system operation, Refer to: Glass, Frames and Mechanisms - Vehicles With: One-Touch Open and Close Front Windows - System Operation and Component Description

Based on the defrost request message received from the HVAC through the MS-CAN, the BCM then send the DDM and PDM an outer mirror defrost command message through the MS-CAN. Based on the message received from the BCM, the DDM controls the operation of the LH heated exterior mirror glass and the PDM controls the operation of the RH heated exterior mirror glass.