Rear Window Heater

The rear window heater comprises a single heater element bonded to the inner surface of the glass. The system is switched on by pressing the momentary switch located on the control panel. When selected, the ATC module transmits a heating request on the high speed CAN bus to the CJB. On receipt of the message, the CJB energizes the rear window heater relay located in the Auxiliary Junction Box (AJB) by providing a ground path for the relay coil. The energized relay provides a battery feed to the heater element. After a period of 12 minutes the ATC module removes the heating request. The CJB then powers down the rear window heater by removing the ground path for the relay coil.

The ATC module will only request rear window heater operation if the engine is running. An engine status signal is provided to the ATC module by the ECM over the high speed CAN bus.