Heated Glass Element: Description and Operation

Rear window Defrost

The rear window defrost feature is controlled by the REM, powertrain control module (PCM), and the dual automatic temperature control (DATC) module. The rear window defrost switch is incorporated in the climate control head. when the switch is selected ON, the DATC module will send a message over the SCP communication network to the REM. The REM will then check its other messages for vehicle rpm from the PCM. If the rpm message is received, the REM will then ground the rear window defrost relay coil control circuit which is hardwired to the REM. The ground signal closes the rear window defrost relay which applies power to the rear window grid through the antenna isolator module. Fault management of the rear window defrost feature will prevent the rear window defrost from operating when a rpm or ignition switch invalid/missing data message is received.