fuel BMW X5 2001 E53 M54 Engine Workshop Manual

M54 ENGINE
Models: E53 X5,
SOP: 3 liter - 4/00
Objectives of the Module:
Purpose of the System:
The M54 engine was developed to meet the needs for ULEV compliancy for emission con-
trol. The increase in displacement allows the engine to fit the X5 All Roads vehicle while still
meeting the demands for power and performance.
INTRODUCTION
The M54 - 6 cylinder engine is being introduced with the 2001 Model Year E53 - X5. The
displacement of the new engine for the X5 is 3 liters and the engine will replace the 2.8 liter
engine in the E46/Z3 series in 6/2000 and E39 series vehicles in 9/2000.
.
Design objectives for the M54 engine were to provide:
• Lower Emissions
• Maintain Fuel Economy
• Maintain Power and Performance levels
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At the end of this section of the handout, you will be able to:
• Identify the changes to the M54 engines over the M52 TU engine.
• List the design objectives for the M54 engine.

M54 ENGINE
Mechanical Changes
In addition to the increased displacement of the M54B30 engine, several mechanical
changes were incorporated into the engine for reduced emissions and increased fuel econ-
omy. These changes include:
• NEW PISTONS - The piston has a shorter skirt compared to the M52 TU and continues
with the graphite coating for friction and emission reducing measures. The piston rings have
been modified to reduce friction.
• CRANKSHAFT - The crankshaft for the 3 liter M54 is adopted from the S52B32 - M3
engine.
• CAMSHAFT - The camshaft for the 3 liter M54 is modified with more lift (9.7 mm) and
new valve springs to accommodate the increased lift.
• INTAKE MANIFOLD - The intake manifold is modified with shorter ram tubes (20mm
shorter on 3 liter. The diameter of the tubes is increased slightly.
• INJECTION VALVES - The diameter of the injection pintle has increased slightly for the
increased displacement of the 3 liter engine.
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ART-0198U29
ART-INJECTOR

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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ART-FUELRAIL

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MS 43 NEW FUNCTIONS
EDK THROTTLE POSITION FEEDBACK SIGNALS
EDK FEEDBACK SIGNAL MONITORING & EDK FAILSAFE OPERATION:
• The EDK provides two separate signals from two integral potentiometers (Pot 1 and Pot
2) representing the exact position of the throttle plate.
• EDK Pot 1 provides the primary throttle plate position feedback. As a redundant safe-
ty feature, Pot 2 is continuously cross checked with Pot 1 for signal plausibility.
• If plausibility errors are detected between Pot 1 and Pot 2, MS 43.0 will calculate the
inducted engine air mass (from HFM signal) and only utilize the potentiometer signal that
closely matches the detected intake air mass.
- The MS 43.0 uses the air mass signalling as a “virtual potentiometer” (pot 3) for a
comparative source to provide failsafe operation.
- If MS 43.0 cannot calculate a plausible conclusion from the monitored pots (1 or 2
and virtual 3) the EDK motor is switched off and fuel injection cut out is activated
(no failsafe operation possible).
• The EDK is continuously monitored during all phases of engine operation. It is also
briefly activated when KL 15 is initially switched on as a “pre-flight check” to verify it’s
mechanical integrity (no binding, appropriate return spring tension, etc). This is accom-
plished by monitoring both the motor control amperage and the reaction speed of the
EDK feedback potentiometers. If faults are detected the EDK motor is switched off and
fuel injection cut off is activated (no failsafe operation possible). The engine does how-
ever continue to run extremely rough at idle speed.
• When a replacement EDK is installed, the MS 43.0 adapts to the new component
(required amperage draw for motor control, feedback pot tolerance differences, etc).
This occurs immediately after the next cycle of KL 15 for approximately 30 seconds.
During this period of adaptation, the maximum opening of the throttle plate is 25%.
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MS 43 NEW FUNCTIONS
EMISSION OPTIMIZED - IGNITION KEY OFF
“Emission Optimized Ignition Key Off” is a programmed feature of the MS 43 control mod-
ule.
After the ECM detects KL 15 being switched OFF, the ignition stays active for two more
individual coil firings. This means that just two cylinders are fired - not two revolutions.
This feature allows residual fuel injected into the cylinders, as the ignition key is switched
off, to be burned as the engine runs down.
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MS 43 NEW FUNCTIONS
DM-TL (DIAGNOSIS MODULE - TANK LEAKAGE)
The M54 engine with the Siemens MS43.0 engine control system uses the DMTL system
for fuel system leakage monitoring. The pump is manufactured by Bosch for use with the
Siemen’s control system.

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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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LEAK DIAGNOSIS TEST PRECONDITIONS
The ECM only initiates a leak diagnosis test every second time the criteria are met. The cri-
teria is as follows:
• Engine OFF with ignition switched OFF.
• Engine Control Module still in active state or what is known as “follow up mode” (Main
Relay energized, control module and DME components online for extended period after
key off).
• Prior to Engine/Ignition switch OFF condition, vehicle must have been driven for a min-
imum of 20 minutes.
• Prior to minimum 20 minute drive, the vehicle must have been OFF for a minimum of 5
hours.
• Fuel Tank Capacity must be between 15 and 85%(safe approximation between 1/4 -
3/4 of a tank).
• Ambient Air Temperature between -7
OC & 35OC(20OF & 95OF )
• Altitude < 2500m(8,202 feet).
• Battery Voltage between 11.5 and 14.5 Volts
When these criteria are satisfied every second time, the ECM will start the Fuel System Leak
Diagnosis Test. The test will typically be carried out once a day i.e. once after driving to
work in the morning, when driving home in the evening, the criteria are once again met but
the test is not initiated. The following morning, the test will run again.

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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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TEST RESULTS
The time duration varies between 45 & 270 seconds depending on the resulting leak diag-
nosis test results (developed tank pressure “amperage” / within a specific time period).
However the chart below depicts the logic used to determine fuel system leaks.