Electrical heater with timer function

Fig 1: Electrical Heater With Timer Function Communication Diagram

Courtesy of VOLVO CARS OF NORTH AMERICA.

The desired departure time is set using the steering wheel module (SWM) (3/254).

The central electronic module (CEM) (4/56) calculates when the heater needs to start. The heater starts 2 hours and 45 minutes before the set departure time, irrespective of the temperature. A text message is displayed in the driver information module (DIM) (5/1) when the electrical heater is running.

The accessory electronic module (AEM) (4/78) electrically controls when the heater should be switched on and off. The engine block heater must be connected to a wall socket. The accessory electronic module (AEM) activates a relay which closes the switch for a heater element.