Rear Window Defrost (if equipped)

When the rear window defrost switch (integral to the HVAC module or Front Controls Interface Module (FCIM) if equipped with navigation system) is pressed and the engine is running, the HVAC module activates the rear window defrost relay located in the Battery Junction Box (BJB). When the rear window defrost relay is active, the rear window defrost grid is energized and the rear window defrost status LED is illuminated. For vehicles equipped with a power sliding rear window, the rear window defrost grid does not activate unless the rear sliding window glass is in the fully CLOSED position due to a glass position switch in series with the grid circuit. The glass position switch is integral to the power sliding rear window assembly. There is a feedback circuit incorporated into the glass position switch which illuminates the rear window defrost switch LED when the defrost grid is active and the sliding glass is fully closed. If the sliding glass is opened while the defrost system is active, the heated mirrors continue to operate and the rear window defrost switch LED is no longer illuminated.

The HVAC module deactivates the rear window defrost relay when one of the following conditions is met:

• The rear window defrost switch is pressed when the feature is active
• Ignition state is changed from RUN to OFF/LOCK
• The 15-minute timing function is completed