System Description
WARNING: This page is about a different car, the 2006 Toyota Camry Solara. However, it is still accessible from the selected car via links, so may be relevant.
The defogger system uses the heater wire in the rear windshield glass to defog the rear windshield glass.
This circuit of this system, which is shared with the outside with the outside rear view mirror heater system, operates in the same manner.