Control Module HVAC: Description and Operation

SYSTEM OPERATION

HVAC Control Module:

HVAC Control Module
The rear window control switch and circuit are integrated into the HVAC control module. When actuating the switch it sends a ground signal to the Body Control Module (BCM). The BCM actuates the relay allowing current to flow through the grid lines for ten minutes upon initial actuation. Then 5 minutes with each subsequent actuation or until either the switch or ignition is turned off. An indicating lamp illuminates the rear window defogger switch.