Rear Window Defrost

When the rear window defrost switch (integral to the HVAC module) is activated, the BCM activates the rear window defrost relay (located in the RJB) and the defrost grid is energized. The rear window defrost system may also be automatically activated as an extra load for accelerated engine warm-up, however the defrost switch status LED remains off unless the defrost switch is activated.

If equipped, the rear window defrost system can also be activated or deactivated by pressing the rear window defrost button on the touchscreen.

The BCM deactivates the rear window defrost relay when one of these conditions is met:

• The rear window defrost switch is pressed.
• If equipped, the rear window defrost button on the touchscreen is pressed.
• Ignition state is changed from ON to OFF.
• A predetermined timer completes.
• Battery voltage has dropped below a specified threshold (load management strategy).