Rear Defogger and Heated Mirrors
CIRCUIT OPERATIONWhen the R. DEFOG button on the Electronic Comfort Control (ECC) Heater and A/C Panel is pressed a rear defogger request is sent to the Body Computer Module (BCM) through the serial data line (800). The BCM commands the Heater and A/C Programmer to energize the Defogger Relay through the serial data line (800).
The Heater and A/C Programmer energizes the Defogger Relay by grounding circuit 291. Battery voltage is then applied to the Rear Defogger and the LH Outside Mirror through the relay contacts.
The BCM controls the timing of the Defoggers. The first Defogger request during an Ignition cycle is 10 minutes. Additional time-outs are 5 minutes. The Defoggers can be enabled only if the engine is running.