2002 BMW X5 Air

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

14
M54engMS43/ST036/6/2000
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%.
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________

18
M54engms43/STO36/6/00
123
DM-TL (DIAGNOSIS MODULE - TANK LEAKAGE)
FUNCTIONAL OVERVIEW:
The DM-TL is located in the drivers side rear wheel well in the X5 and next to the charcoal
canister on the E46 - M54.
1. In it’s inactive state, filtered fresh air enters the evaporative system through the sprung
open valve of the DM-TL.
2. When the DME activates the DM-TL for leak testing, it first activates only the pump
motor. This pumps air through a restrictor orifice (1.0 or 0.5 mm) which causes the elec-
tric motor to draw a specific amperage value. This value is equivalent to the size of the
restrictor.
3. The solenoid valve is then energized which seals the evap system and directs the pump
output to pressurize the evap system.
The evap system is detected as having a large leak if the amperage value is not realized, a
small leak if the same reference amperage is realized or no leak if the amperage value is
higher than the reference amperage.

20
M54engMS43/ST039/3/17/00
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.

21
M54engMS43/ST039/3/17/00
LEAK DIAGNOSIS TEST
PHASE 1 - REFERENCE MEASUREMENT
The ECM activates the pump motor. The pump pulls air from the filtered air inlet and pass-
es it through a precise 0.5mm reference orifice in the pump assembly.
The ECM simultaneously monitors the pump motor current flow . The motor current raises
quickly and levels off (stabilizes) due to the orifice restriction. The ECM stores the stabilized
amperage value in memory. The stored amperage value is the electrical equivalent of a 0.5
mm (0.020”) leak.

22
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.

25
M54engMS43/ST036/6/20000
OXYGEN SENSOR SIGNAL INFLUENCE ON INJECTOR “OPEN” TIME
The ECM monitors the:
• Amplitude of the signal (highest voltage or range sensor is producing)
• Switching time of the signal (how fast from lean to rich)
• Frequency of complete cycles (how many within a period of time)
These characteristics provide info to the ECM that reflect the overall condition of the sen-
sor.
POST CATALYTIC CONVERTER SENSOR SIGNAL
The post catalyst O2 sensors monitor the efficiency of the catalyst as a requirement of OBD
II. This signal also provides feedback of the pre-catalyst sensors efficiency and can cause
the ECM to “trim” the ms injection time to correct for slight deviations.
• If the catalyst is operating efficiently, most of the remaining oxygen in the exhaust gas
is burned (lack of O2 - “constant lean signal”).
The sensor signal fluctuates slightly in the higher end of the voltage scale.
• If the post sensor shows excessive fluctuations
(which echo the scope pattern of the pre
sensor), this indicates that the catalytic converter is not functioning correctly and cannot
consume the O2 (fault set).
• If the post sensor fluctuations move out of the normal voltage “window”, this indicates
that the pre sensor is not performing properly due toslight
deterioration. These systems
can also “trim” the ms injection time to compensate for this.
The constantly changing oxygen sensor input to the ECM is needed to correct the ms
injection time to ensure that the ideal air/fuel ratio is maintained.