Rear Defogger Switch - Operation

OPERATION

When the rear window defogger switch is pressed to the on position, the A/C-heater control sends a request message to the Totally Integrated Power Module (TIPM) to energize the EBL relay to provide battery current to the rear window defogger grid lines and to the heated side view mirrors, when equipped. An amber indicator will illuminate when the rear window defogger system is activated.

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