5 Series E39 530d (M57) SAL
9. Filler neck
25. Fuel evaporation control valve
10. Fuel filler cap
26. Intake manifold
11. Tank expansion line
27. Vacuum line (leak diagnosis pump USA only)
12. Refuelling vent line (USA only)
28. Activated carbon filter
12. Operating vent line (all countries)
29. Breather pipe
13. Operating vent line
30. Leak diagnosis pump (USA only)
14. Expansion tank
31. Tank leak diagnosis module (USA only)
15. Rollover valve
32. Dust filter (USA only)
1.2 Functional description (please refer to drawing 1.4/1.5/1.6/1.7/1.8)
Fuel system
The right-hand side of the saddle-shaped fuel tank has a surge chamber with the electric fuel delivery pump.
The surge chamber guarantees correct fuel supply from the fuel delivery pump in all operating states of the vehicle.
The suction jet pump installed in the base of the surge chamber supplies the surge chamber with fuel.
Fuel is transferred from the left-hand side of the fuel tank to the surge chamber by the suction jet pump integrated in
the tank expansion line. Both suction jet pumps are driven by the fuel return line.
The pressure relief valve controls the pressure required for the suction jet pumps to operate. The overflow protection
valve protects the fuel return line. Should the pressure drop in the event of damage or the fuel return line becoming
separated, the valve will close.
This prevents the fuel from overflowing from the fuel tank in extreme vehicle positions (rollover, inclination).
The non-return flap prevents the fuel from sloshing back in the fuel filler neck when the fuel pump nozzle cuts off.
Fuel supply to the engine
M52TU (please refer to drawing 1.5, view A)
The fuel is fed from the electric fuel delivery pump to the fuel rail via the fuel feed line and the fuel filter. Excess fuel is
diverted back to the fuel tank by the pressure regulator fitted to the fuel rail and the fuel return line.
M52 USA and M73 (please refer to drawing 1.5/1.6)
The fuel is fed from the electric fuel delivery pump to the fuel rail via the fuel feed line and the fuel filter.
Excess fuel is fed back to the fuel tank by the 3/2-way valve (please refer to view A), the pressure regulator and the
fuel return line.
This engine fuel circuit with return from the fuel rail is activated for the engine start and for a predefined period of < 1
minute thereafter.
After this phase, the 3/2-way valve cuts in and interrupts the fuel return from the fuel rail. At the same time, the pipe
junction immediately on the fuel filter is activated by the 3/2-way valve to the pressure regulator (please refer to view
B).
The fuel rail is then return-free.
M62TU/54 (please refer to drawing 1.4, view B and drawing 1.7/1.8)
The pressure regulator and fuel filter are combined in a single unit.
The fuel is fed from the electric fuel delivery pump to the fuel rail via the fuel feed line and the fuel filter/pressure
regulator unit.
The fuel rail is return-free. The fuel flows back to the fuel tank directly from the fuel filter/pressure regulator unit.
Ventilation system USA (please refer to drawing 1.6/1.7/1.8)
The fuel tank is ventilated through the refuelling vent line during refuelling.
With its large cross-sectional area, the refuelling vent line quickly feeds the displaced volume (fuel vapours) to the
activated carbon filter via the expansion tank.
The activated carbon absorbs the fuel contained in the fuel vapours. The purified air is then fed into the atmosphere
through the breather pipe, the leak diagnosis pump or the tank leak diagnosis module and dust filter.
SBT Functional description of fuel supply system E38 E39 E46 E52 E53
BMW AG - TIS
21.02.2013 06:26
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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