5 Series E60 525i (N52) SAL
16 00
General function description for fuel supply systems
Fuel supply systems, spark-ignition engines
Fuel system
The electric fuel pump in the fuel tank generates the pressure in the fuel system which is set by the pressure
regulator to a specific level.
Tank venting system
The tank venting system is an enclosed system which is vented via a carbon canister. The carbon is incorporated
in the carbon canister as granulate. The large surface of the carbon stores the fuel vapors which occur in the fuel
tank. The carbon canister must be regenerated on a regular basis so as to be able to continue storing fuel vapors.
Regeneration is performed by way of purging with fresh air via the intake manifold. This process is controlled by
the engine control unit.
Fuel supply systems, diesel engines
Fuel system
The electric fuel pump in the fuel tank supplies the engine with fuel. Two types of high-pressure pump are used for
cylinder injection.
1.
The distributor injection pump supplies each cylinder directly with fuel via the corresponding injection nozzle.
2.
The high-pressure pump for the common rail systems generates in the fuel rail the necessary pressure for all
the injection nozzles.
In common rail systems, a further pump (inline pump, M57/gear pump, M67) is connected between the high-
pressure pump and the electric fuel pump. This pump supports the fuel pump in the fuel tank in the event of a high
fuel demand.
Tank venting system
Diesel fuel is non-volatile and therefore a carbon canister is not required. The fuel tank is vented directly to
atmosphere.
RA General function description for fuel supply systems
BMW AG - TIS
15.02.2013 06:18
Issue status (12/2007) Valid only until next DVD is issued
Copyright
Page - 1 -