Rear Window Defrost
WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.
The HVAC module controls the state of the rear window defrost relay. When the rear window defrost switch (integral to the Front Controls Interface Module (FCIM)) is pressed, the FCIM sends a message to the HVAC module through the Controller Area Network (CAN). When the HVAC module receives the rear window defrost request, the HVAC module will activate 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 will be energized.