2005 BMW X5 M54 Engine Workshop Manual

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M54engMS43/ST036/6/20000
SYSTEM OVERVIEW I-P-O
Service
Engine
Soon
ART-IPO46X.EPS

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M54engMS43/ST036/6/2000
MS 43 NEW FUNCTIONS
ELECTRONIC THROTTLE SYSTEM - EML
The M54 engine with MS 43 engine control uses an electronic throttle control system
adopted from the ME 7.2 system on the M62 engine. The system incorporates an electric
throttle valve (EDK) and pedal position sensor (PWG) for engine power control.
The MS 43 control module monitors the PWG input and activates the EDK motor based on
the programmed maps for throttle control. The MS 43 module self checks the activation of
the EDK via feedback potentiometers motor on the EDK motor.
Additional functions of the EML system include:
• Cruise control function
• DSC throttle interventions
• Maximum engine and road speed control
ART-SCANDIAGRAM

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M54engMS43/ST036/6/20000
MS 43 NEW FUNCTIONS
ACCELERATOR PEDAL SENSOR
The accelerator pedal sensor is similar to the PWG used on the ME 7.2 system. It is inte-
grated into the accelerator pedal housing. Two hall sensors are used to provide the driver’s
input request for power.
The hall sensors receive power (5 volts) and ground from the MS 43 control module and
produce linear voltage signals as the pedal is pressed from LL to VL.
PWG SENSOR 1 = 0.5 to 4.5 V
PWG SENSOR 2 = 0.5 to 2.0 V
The MS 43 control module uses the
signal from sensor 1 as the driver’s
request and the signal from sensor 2
as plausibility checking.
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HS
12 3 4 5
MS 43.0
HS
SIGNAL 1
SIGNAL 2
HALL SENSOR
POWER
61460015

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M54engMS43/ST036/6/2000
MS 43 NEW FUNCTIONS
ACCELERATOR PEDAL SENSOR
PWG SIGNAL MONITORING & PWG FAILSAFE OPERATION:
• As a redundant safety feature the PWG provides two separate signals from two integral
angle hall sensors (HS #1 and HS #2) representing the driver’s request for throttle acti-
vation.
• If the monitored PWG signals are not plausible, MS 43.0 will only use the lower of the
two signals as the driver’s pedal request input providing failsafe operation. Throttle
response will be slower and maximum throttle position will be reduced.
• When in PWG failsafe operation, MS 43.0 sets the EDK throttle plate and injection time
to idle (LL) whenever the brake pedal is depressed.
• When the system is in PWG failsafe operation, the instrument cluster matrix display will
post “Engine Emergency Program” and PWG specific fault(s) will be stored in memory.
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E46ICPOT-SIG.

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MS 43 NEW FUNCTIONS
EDK THROTTLE POSITION FEEDBACK SIGNALS
The EDK throttle plate is monitored by two integrated potentiometers. The potentiometers
provide linear voltage feedback signals to the control module as the throttle plate is opened
and closed.
Feedback signal 1 provides a signal from 0.5 V (LL) to 4.5 V (VL).
Feedback signal 2 provides a signal from 4.5 V (LL) to 0.5 V (VL)
Potentiometer signal 1 is the primary feedback signal of throttle plate position and signal 2
is the plausibility cross check through the complete throttle plate movement.
ART-EDK.EPS1
ART-E46ICPWG2.

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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%.
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MS 43 NEW FUNCTIONS
MAIN RELAY MONITOR
The MS 43.0 system incorporates a new monitoring feature for terminal 87 (KL 87) of the
main relay. The relay is monitored internally for the voltage level at KL 87. Five seconds after
the ignition key is switched on, and the voltage at the KL 15 input is greater than 9 volts,
the control module checks the voltage at KL 87.
If the voltage difference between the two terminals is greater than 3 volts, a fault will be
stored in the ECM.
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ART-E46ICMS43RELAY

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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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ART-E46ICEMIOPT