Rear demist

Fig 1: Identifying Rear Demist Input And Output Signals

Courtesy of VOLVO CARS OF NORTH AMERICA.

Rear demist (9/2) is activated by pressing the switch on the climate control module (CCM) (3/112). The climate control module (CCM) transmits the data via the Control area network (CAN) to the central electronic module (CEM) (4/56). The central electronic module (CEM) checks that the conditions to start the demist have been met. If the conditions are met, a request is sent via the Control area network (CAN) to the rear electronic module (REM) (4/58) to activate the relay (2/82). The rear electronic module (REM) powers the relay and the demister is powered.

The central electronic module (CEM) also transmits a request via the Control area network (CAN) back to the climate control module (CCM) to light the LED in the switch.