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.
When the rear window defrost switch (integral to the Front Controls Interface Module (FCIM)) is pressed, a message is sent to the HVAC module through the Controller Area Network (CAN). When the HVAC module receives the rear window defrost request, it 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.
The HVAC module will deactivate 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 switch state is changed from RUN to OFF/LOCK.
- The 10 minute timing function is completed.