fuel filter BMW X5 2003 E53 M54 Engine Workshop Manual

M54 ENGINE
MECHANICAL CHANGES
NON RETURN FUEL RAIL SYSTEM
The M54 engine with MS 43.0 control uses the non return fuel rail system introduced on
the M62 TU engine. The system meets running loss compliance without the use of the 3/2-
way solenoid valve currently used on the M52 TU engine.
The regulated fuel supply is controlled by
the fuel pressure regulator integrated in
the fuel filter. The fuel return line is also
located on the filter.
The M54 engine uses an Electronic Controlled
Throttle Valve (EDK) for intake air control. The
idle control valve and turbulence function of the
intake manifold carries over from the M52 TU
engine.
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M54engMS43/ST036/6/20000
ART-FUELRAIL

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M54engMS43/ST039/3/17/00
DM-TL (DIAGNOSIS MODULE - TANK LEAKAGE)
FUNCTION
The DC Motor LDP ensures accurate fuel system leak detection for leaks as small as
0.5mm (.020”). The pump contains an integral DC motor which is activated directly by the
engine control module. The ECM monitors the pump motor operating current as the mea-
surement for detecting leaks.
The pump also contains an ECM controlled change over valve that is energized closed dur-
ing a Leak Diagnosis test. The change over valve is open during all other periods of oper-
ation allowing the fuel system to “breath” through the inlet filter (similar to the full down
stroke of the current vacuum operated LDP).

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M54engMS43/ST039/3/17/00
PHASE 2 - LEAK DETECTION
The ECM energizes the Change Over Valve allowing the pressurized air to enter the fuel sys-
tem through the Charcoal Canister, The ECM monitors the current flow and compares it
with the stored reference measurement over a duration of time.
Once the test is concluded, the ECM stops the pump motor and immediately de-energizes
the change over valve. This allows the stored pressure to vent thorough the charcoal can-
ister trapping hydrocarbon vapor and venting air to atmosphere through the filter.

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M54engMS43/ST036/6/20000
The dual VANOS in conjunction with the variable intake manifold provides an additional
emission control feature.
Because of the improved combustion, the camshaft timing is adjusted for more overlap.
The increased overlap supports internal exhaust gas recirculation (EGR) which reduces
tailpipe emissions and lowers fuel consumption.
During the part load engine range, the intake camshaft overlap opens the intake valve. This
allows limited exhaust gas reflow the intake manifold.
The “internal” EGR reduces the cylinder temperature thus lowering NOx. This feature pro-
vides EGR without the external hardware as seen on previous systems.
INLET
TURBULENCE
IDLE AIR
CONTROL VALVEMDK
INT. EGR
CATALYST
CLOSE TO
ENGINESECONDARY
AIR
INJECTION
(AIR FILTER)OUTLET-VANOS
(228/80-105)INLET-VANOS
(228/80-120)