2002 BMW X5 Idle valve

Initial Print Date: 02/2000Revision Date: 6/2000
Subject Page
M54 Engine
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Mechanical changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Performance Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Review Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Siemen’s MS 43.0 System
• Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
• I - P - O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
MS 43.0 New functions
• Electronic throttle Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
• Accelerator Pedal Sensor (PWG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
• Electronic Throttle Valve (EDK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
• Main Relay Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
• Engine Optimized Ignition Key OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
• Diagnosis Module Tank Leakage (DM-TL) . . . . . . . . . . . . . . . . . . . . . . .17
• DM-TL Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
• DM-TL Test Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Carry Over Functions
Inputs
• Oxygen Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
• Camshaft Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
• Crankshaft Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
• Misfire Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
• OBD Fault Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
• Mass Air Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Outputs
• VANOS Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
• Electric Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
• Secondary Air Injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
• Engine Speed Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
• RZV Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
• Resonance - Turbulence Manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
• Idle Speed control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
• Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
• Purge Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Table of Contents

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.
5
M54engMS43/ST036/6/20000
ART-FUELRAIL

32
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.

35
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)

41
M54engMS43/ST036/6/20000
RESONANCE/TURBULENCE INTAKE SYSTEM
On the M54, the intake manifold is split into 2 groups of 3 (runners) which increases low
end torque. The intake manifold also has separate (internal) turbulence bores which chan-
nels air from the idle speed actuator directly to one intake valve of each cylinder (matching
bore of 5.5mm in the cylinder head).
Routing the intake air to only one intake valve causes the intake to swirl in the cylinder.
Together with the high flow rate of the intake air due to the small intake cross sections, this
results in a reduction in fluctuations and more stable combustion.
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MDK
HFMHFM
MAGNETIC
VALVE
VACUUM
UNIT
MS42.0MS42.0
RAM TUBE
MAIN MAINIFOLD
RESONANCE TUBE
IDLE AIR CONTROL VALVE
(ZWD)
RESONANCE MANIFOLD
CRANKCASE VENTILATIONTURBULENCE MANIFOLD
TURBULENCE BORE 0:5.5mm
MS 43.0
EDK

45
M54engMS43/ST036/6/20000
IDLE SPEED CONTROL
The ECM determines idle speed by controlling an idle speed actuator (dual winding rotary
actuator) ZWD 5.
The basic functions of the idle speed control are:
• Control the initial air quantity
(at air temperatures <0 C,
the EDK is simultaneously
opened)
• Variable preset idle based on
load and inputs
• Monitor RPM feedback for
each preset position
• Lower RPM range intake air
flow (even while driving)
• Vacuum limitation
• Smooth out the transition from acceleration to deceleration
Under certain engine operating parameters, the EDK throttle control and the idle speed
actuator (ZWD) are operated simultaneously.This includes All idling conditions and the tran-
sition from off idle to load.
As the request for load increases, the idle valve will remain open and the EDK will supply
any additional air volume required to meet the demand.
Emergency Operation of Idle Speed Actuator:
If a fault is detected with the idle speed actuator, the ECM will initiate failsafe measures
depending on the effect of the fault (increased air flow or decreased air flow).
If there is a fault in the idle speed actuator/circuit, the EDK will compensate to maintain idle
speed. The EML lamp will be illuminated to inform the driver of a fault.
If the fault causes increased air flow (actuator failed open), VANOS and Knock Control are
deactivated which noticeably reduces engine performance.
MDK
HFMHFM
MAGNETIC
VALVE
VACUUM
UNIT
MS42.0MS42.0
RAM TUBE
MAIN MAINIFOLD
RESONANCE TUBE
IDLE AIR CONTROL VALVE
(ZWD)
RESONANCE MANIFOLD
CRANKCASE VENTILATIONTURBULENCE MANIFOLD
TURBULENCE BORE 0:5.5mm
MS 43.0
EDK