Rear Window Defrost

The engine must be running for the rear window defrost system to operate. The rear window defrost system is controlled by the BCM. When the rear window defrost switch (integral to the HVAC module) is pressed, the BCM supplies voltage to the rear window defrost grid. An LED indicator illuminates when the rear window defrost is activated. The rear defrost self actuates when the ambient air temperature is less than 5° C (41° F) and engine coolant temperature is less than 60° C (140° F). The rear window defroster LED indicator does not illuminate when the rear defroster self actuates.