Voltage Supply DME

Main relay (R50)

Function
The main relay is used to ensure the power supply to the fuel injector valves, to the camshaft sensor and to the crankshaft sensor as well as to other system components. The relay has an additional protective function, whereby it is not activated in the event of incorrect battery polarity. The relay is activated when the engine control module connects to ground.

Installation Location
The main relay is located in the fuse box in the engine compartment.

Failure
If the relay remains open continuously, the engine control module does not become active. The engine does not start. If the relay remains closed without interruption, the battery is discharged.