timing BMW X5 2002 E53 M54 Engine Workshop Manual

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M54engMS43/ST036/6/20000
EMISSIONS RELEVANT:
During an interval of 1000 crankshaft revolutions
the misfire events of all cylinders are
added and if the sum is greater than a predetermined value a fault will be set identifying the
particular cylinder(s). The “Service Engine Soon” light will be illuminated during and after
the second cycle if the fault is again present.
CATALYST DAMAGING:
During an interval of 200 crankshaft revolutions
the misfire events of all cylinders are added
and if the sum is greater than a predetermined value a fault will be set identifying the par-
ticular cylinders(s). The “Service Engine Soon” lamp:
• On vehicles with a Siemens Control Module (M54 engines) - the lamp will immediately go
to a steady illumination since fuel to the injector(s) is removed. Fuel cut-off to the cylin-
der will resume after several (
>>7) periods of decel if crankshaft sensor adaptation is suc-
cessfully completed or the engine is shut-off and restarted.
In each case the number of misfire events permitted is dependent on engine speed, load
and temperature map.
The process of misfire detection continues well after the diagnostic drive cycle requirements
have been completed. Misfire detection is an on-going monitoring process
that is only dis-
continued under certain conditions.
Misfire detection is only disabled under the following conditions:
___________________________________________________________________
___________________________________________________________________
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REQUIREMENTSSTATUS/CONDITION
Engine Speed< 512 RPM
Engine LoadVarying/Unstable
Throttle AngleVarying/Unstable
TimingTiming retard request active (i.e. knock
control - ASC, AGS)
Engine Start-upUp to 5 seconds after start-up
A/CUp to 0.5 seconds after A/C activation
Decel fuel cut-offActive
Rough road recognitionActive
ASC ControlActive

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M54engMS43/ST036/6/2000
MS 43 CARRY OVER FUNCTIONS
OUTPUT FUNCTIONS -VANOS CONTROL
With the double VANOS system, the valve timing is changed on both the intake and the
exhaust camshafts.
Double VANOS provides the following benefits:
• Torque increase in the low to mid (1500 - 2000 RPM) range without power loss in the
upper RPM range.
• Less incomplete combustion when idling due to less camshaft overlap (also improves
idle speed characteristics).
• Internal exhaust gas recirculation (EGR) in the part load range (reduces NOx and post-
combustion of residual gasses in the exhaust)
• Rapid catalyst warm up and lower “raw” emissions after cold start.
• Reduction in fuel consumption
Double VANOS consists of the following parts:
• Intake and exhaust camshafts with helical gear insert
• Sprockets with adjustable gears
• VANOS actuators for each camshaft
• 2 three-way solenoid switching valves
• 2 impulse wheels for detecting camshaft position
• 2 camshaft position sensors (Hall effect)
The “initial” timing is set by gear positioning (refer to the Repair Instructions for details) and
the chain tensioner. As with the previous VANOS, the hydraulically controlled actuators
move the helical geared cups to regulate camshaft timing. The angled teeth of the helical
gears cause the pushing
movement of the helical cup to be converted into a rotational
movement. This rotational movement is added to the turning of the camshafts and cause
the camshafts to “advance” or “retard”. The adjustment rate is dependent oil temperature,
oil pressure, and engine RPM.

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M54engMS43/ST036/6/20000
NOTE: With extremely hot oil temperatures Vanos is deactivated (Power loss). If the oil is
too thick (wrong viscosity) a fault could be set.
When the engine is started, the camshafts are in the “failsafe” position (deactivated). The
intake camshaft is in the RETARDED position - held by oil pressure from the sprung open
solenoid. The exhaust camshaft is in the ADVANCED position - held by a preload spring in
the actuator and oil pressure from the sprung open solenoid.
After 50 RPM (2-5 seconds) from engine start, the ECM is monitoring the exact camshaft
position.
The ECM positions the camshafts based on engine RPM and the throttle position signal.
From that point the camshaft timing will be varied based on intake air and coolant temper-
atures.
The double VANOS system is “fully variable”. When the ECM detects the camshafts are in
the optimum positions, the solenoids are modulated (approximately 100-220 Hz) maintain-
ing oil pressure on both sides of the actuators to hold the camshaft timing.
CAUTION:
The VANOS MUST
be removed and installed exactly as described in the Repair
Instructions!
NOTE: If the VANOS camshaft system goes to the failsafe mode (deactivated) there will be
a noticeable loss of power. This will be like driving with retarded ignition or starting from a
stop in third gear.
KL 15 KL 15
MS42.0
SOLENOID
OIL TEMP.
SENSOR TWO POSITION PISTON HOUSING
WITH INTERNAL/EXTERNAL
HELICAL GEAR CUP TWO POSITION PISTON
HOUSING WITH
INTERNAL/EXTERNAL
HELICAL GEAR CUP
ENGINE
OIL SUPPLY VENT VENT
SOLENOID
SENSOR SENSOR
MS42
ECMEXHAUST
INTAKE
MS42.0
ECM
MS 43.0
MS 43.0
MS 43.0

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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)