Body control unit (BCU) is responsible for monitoring and controlling various electronic accessories in a vehicle body. Typically, in a car the BCU controls the power windows, power mirrors, air conditioning, immobilizer system, central locking, etc. The BCU communicates with other ECUs using the same bus of the vehicle, and its main application is controlling load drivers – actuating relays that in turn perform actions in the vehicle such as locking the doors, flashing the turn signals, or dimming the interior lighting.