Heated Rear Window

WARNING: This page is about a different car, the 2009 Land Rover Range Rover, 2008 Land Rover Range Rover, and 2007 Land Rover Range Rover. However, it is still accessible from the selected car via links, so may be relevant.

When the engine is running and the heated rear window is selected on, the automatic temperature control (ATC) module illuminates the light emitting diode (LED) above the switch and energizes the heated rear window relay in the AJB (auxiliary junction box). After 10 minutes (when ambient temperature is -15°C (5°F) or above) or 17 minutes (when ambient temperature is less than -15°C (5°F)), the automatic temperature control (ATC) module extinguishes the light emitting diode (LED) and operates the heated rear window at low power for 60 minutes. During the 60 minutes, the automatic temperature control (ATC) module cycles the heated rear window relay off for 80 seconds and on for 40 seconds. If the heated rear window switch is pressed again during the low power phase, the automatic temperature control (ATC) module illuminates the light emitting diode (LED) again and returns the heated rear window to full power by keeping the heated rear window relay energized for 5 minutes. At the end of the 5 minutes the light emitting diode (LED) is extinguished and the 60 minutes low power phase is repeated.

The automatic temperature control (ATC) module outputs a K bus message when the heated rear window is active. The message allows the navigation computer to compensate for the effect of the magnetic field generated when the heated rear window is active. In addition, the generic electronic module (GEM) transfers the message onto the P bus for the door modules, which activate the door mirror heaters together with the heated rear window.