Circuit Description

Power Mirror Heaters

How the Circuit Works

Power Supply
Battery voltage is supplied at all times through fuse 7 (in the driver's under-dash fuse/relay box) to the driver's and front passenger's MPCS units.

With the ignition switch in ON (II), battery voltage is supplied through fuse 30 (in the driver's under-dash fuse/relay box) to the climate control unit.

Defogger operation
When the rear window defogger/power mirror heater switch is pressed, the climate control unit sends a signal through the B-CAN communication line to the relay control module and the driver's MPCS unit.

The driver's MPCS unit provides voltage to the left power mirror heater. The driver's MPCS unit sends a power mirror heater operation signal to the front passenger's MPCS unit through the UART communication line. The front passenger's MPCS unit provides voltage to the right power mirror heater.

The mirror heaters can be turned off by pressing the rear window defogger switch/power mirror heater switch a second time or by turning the ignition switch to LOCK (0). The mirror heaters will also shut off after 5 to 40 minutes of operation (depending on the ambient temperature).