Rear Defogger Switch - Operation

OPERATION

An amber indicator illuminates when the rear window defogger switch is activated. When activated, the Cabin Compartment Node (CCN) sends a request signal to the Totally Integrated Power Module (TIPM) to energize the internal Electric Back Light (EBL) (rear window defogger) high side driver to provide battery current to the rear window defogger grid lines.

NOTE: The EBL system turns off automatically after 10 minutes of initial operation. Each following activation cycle of the EBL system will last 5 minutes.

The EBL system will be automatically turned off after an initial programmed time interval of about 10 minutes as long as the ignition switch is in RUN. After the initial time interval has expired, if the rear window defogger switch is pressed to ON again during the same ignition cycle, the EBL system will automatically turn off after about 5 minutes. The EBL system will also turn off if the ignition switch is turned to any position other than RUN or by manually pressing the rear window defogger switch a second time.

The rear window defogger switch is diagnosed using a scan tool Testing and Inspection.

The rear window defogger switch and indicator lamp cannot be adjusted or repaired and the A/C-heater control must be replaced if found inoperative or damaged A/C and Heater Control - Removal.