Heated Glass Element Switch: Description and Operation
SWITCH-REAR WINDOW DEFOGGERDESCRIPTION
The switch for the rear window defogger (EBL) system (1) is located in the accessory switch bezel, which is mounted to the instrument panel center bezel (2). When the rear window defogger switch is pressed to On position a request signal is sent to the cabin compartment node (CCN), which sends a message to the totally integrated power module (TIPM) to operate the EBL system.
When the high side driver in the totally integrated power module (TIPM) is energized, current is directed to the rear defogger grid lines and to the heated side view mirrors (when equipped). The grid lines heat the glass to help clear the surface of fog or frost.
OPERATION
An amber indicator will illuminate when the rear window defogger switch is activated. When activated, the switch sends a request signal to the cabin compartment node (CCN), which sends a message to the totally integrated power module (TIPM) to energize the internal EBL high side driver to provide battery current to the rear window defogger grid lines and to the heated side view mirrors (when equipped).
NOTE: The EBL system turns off automatically after ten minutes of initial operation. Each following activation cycle of the EBL system will last five minutes.
The EBL system will be automatically turned off after an initial programmed time interval of about ten minutes as long as the ignition switch is the Run position. After the initial time interval has expired, if the rear window defogger switch is turned on again during the same ignition cycle, the EBL system will automatically turn off after about five minutes. The EBL system will automatically shut off if the ignition switch is turned to any position other than Run, or it can be turned off manually by pressing the rear window defogger switch a second time.
The rear window defogger switch is diagnosed using a scan tool.
The rear window defogger switch and the rear window defogger indicator cannot be repaired and, if faulty or damaged, the switch must be replaced.