Electric fuel pump nominal values (N52 engine)
The electronic fuel pump is an in-tank pump and it supplies the engine with fuel (diesel fuel or gasoline). The electric fuel pump is activated via either an electronic fuel pump control module (EKPS) or a fuel pump relay. If the vehicle is fitted with the electronic fuel pump control system, the electric fuel pump is activated in line with requirements. The engine control unit (DME) calculates the required fuel quantity based on the driver's choice and the operating condition of the engine at that particular time. The required fuel quantity is transmitted to the electronic fuel pump control module (EKPS) in the form of a message on the CAN bus. This message is converted into a pulse-width-modulated output signal by the fuel pump control module (EKPS). For this purpose, the characteristic curves for the fuel requirements are stored in the fuel pump control module (EKPS). The characteristic curves are coded for the specific motor and model.
If the electric fuel pump is activated via the fuel pump relay, the engine control unit (DME) switches the electric fuel pump on or off. The fuel pressure in the feed line is approx. 5 bar and is regulated at this level by a pressure limiting valve inside the electric fuel pump.
DME: Digital Motor Electronics