1999 BMW 735i Motor

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INTEGRAL ELECTRIC THROTTLE SYSTEM (EML)
FUNCTIONAL DESCRIPTION
When the accelerator pedal
is moved, the PWG pro-
vides a change in the mon-
itored signals. The ME 7.2
compares the input signal
to a programmed map and
appropriately activates the
EDK motor via proportional-
ly high/low switching cir-
cuits. The control module
self-checks it’s activation of
the EDK motor via the EDK
feedback potentiometers.
Requirements placed on the Electric Throttle System:
• Regulate the calculated intake air load based on PWG input signals and programmed
mapping.
• Control idle air when LL detected with regard to road speed as per previous systems.
• Monitor the driver’s input request for cruise control operation.
• Automatically position the EDK for accurate cruise control (FGR) operation.
• Perform all DSC III throttle control interventions.
• Monitor and carryout max engine and road speed cutout.

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PWG SIGNAL MONITORING & PWG FAILSAFE OPERATION:
• As a redundant safety feature the PWG provides two separate signals from two integral
potentiometers (Pot 1 and Pot 2) representing the driver’s request for throttle activation.
• If the monitored PWG potentiometer signals are not plausible, ME 7.2 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, ME 7.2 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.
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, ME 7.2 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 ME 7.2 uses the air mass signalling as a “virtual potentiometer” (pot 3) for a
comparative source to provide failsafe operation.
- If ME 7.2 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 ME 7.2 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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EDK THROTTLE POSITION FEEDBACK SIGNALS
The EDK throttle plate position is monitored by two integrated potentiometers. The poten-
tiometers provide DC voltage feedback signals as input to the ME 7.2 for throttle and idle
control functions.
Potentiometer signal 1 is the primary signal, Potentiometer sig-
nal 2 is used as a plausibility cross-check through the total
range of throttle plate movement.
EDK FEEDBACK
SIGNAL MONITORING & FAILSAFE OPERATION:
• If plausibility errors are detected between Pot 1 and Pot 2, ME 7.2 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 ME 7.2 uses the air mass signalling as a “virtual potentiometer” (pot 3) for a
comparative source to provide failsafe operation.
- If ME 7.2 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) by monitoring 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 activat-
ed (no failsafe operation possible). The engine does however continue to run extreme-
ly rough at idle speed.

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OUTPUT CONTROL FUNCTIONS
FUEL PUMP RELAY CONTROL
ME 7.2 controls the fuel pump relay as with previous systems with regard to engine speed
input for continual activation of the relay.
The ME 7.2 will switch off the fuel pump relay when an airbag is activated as an addition-
al safety function. The signal is passed from the MRS III control module to the ME 7.2 over
the CAN line
E BOX FAN CONTROL
The E Box fan is controlled by ME 7.2. The control module
contains an integral NTC temperature sensor for the pur-
pose of monitoring the E box temperature and activating the
fan.
When the temperature in the E-Box exceeds predetermined
values, ME 7.2 provides a switched ground for the E Box fan
to cool the E box located control modules.
With every engine start-up, ME 7.2 briefly activates the fan
ensuring continued fan motor operation for the service life of
the vehicle. This feature is intended to prevent fan motor
“lock up” from lack of use due to pitting or corrosion over
time.

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SECONDARY AIR INJECTION
Secondary air injections required to pre-heat the catalytic converters for OBD II compliance.
The system consists of the same components as previous systems with V8 specific loca-
tions.
The DME ME7.2 control unit controls the vacuum vent valve and the secondary air injec-
tion pump relay separately but simultaneously.
The secondary air pump operates at a start temperature of between 10°C and 40°C. It con-
tinues to operate for a max. of 2 minutes at idle speed.
ME 7.2 contributes an additional correction factor for secondary air “on” time with the addi-
tional input from the integral ambient barometric pressure sensor.
This sensor provides a base value to calculate the air mass being
injected into the exhaust system. This helps to “fine tune” the sec-
ondary air injection “on” time, optimizing the necessary air flow
into the exhaust system which reduces the time to catalytic con-
verter light-off.
VACUUM
VACUUM
VENT VALVENONPUMP/MOTOR
AIR PUMP SUPPLY HOSE
AIR DELIVERY TUBE WITH O RING
CONNECTIONS TO CYLINDER HEADS
VACUUM
CONTROL TO
NON RETURN
VA LV E

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AUXILIARY FAN CONTROL
The Auxiliary Fan motor incorporates an out-
put final stage that activates the fan motor at
variable speeds.
The auxiliary fan is controlled by ME 7.2. The
motor output stage receives power and
ground and activates the motor based on a
PWM signal (10 - 100 Hz) received from the
ME 7.2.
Similar to the aux fan in the E46 with MS 42.0
control, the fan is activated based on the fol-
lowing factors:
• Radiator outlet temperature sensor input exceeds a preset temperature.
• IHKA signalling via the K and CAN bus based on calculated refrigerant pressures.
• Vehicle speed
• Battery voltage level
When the over temperature light in the instrument cluster is on (120
OC) the fan is run in the
overrun function. This signal is provided to the DME via the CAN bus. When this occurs
the fan is run at a frequency of 10 Hz.
FAN MOTOR MODULE
POWER, GROUND & SIGNAL WIRES

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ELECTRIC THROTTLE VALVE (EDK) CONTROL
• The throttle valve assembly of the M62 TU is an
electric throttle valve (EDK) controlled by an inte-
gral EML function of the ME 7.2.
• The throttle plate is positioned by a gear reduction
DC motor drive.
• The motor is controlled by proportionately
switched high/low PWM signals at a basic fre-
quency of 2000 Hz.
• Engine idle speed control is a function of the EDK.
Therefore, the M62 TU does not require a separate
idle control valve.
HARNESS
CONNECTORMOTOR
REDUCTION
GEARS
POTENTIOMETER WIRES
THROTTLE
PLATE
EDK ADAPTATION
PROCEDURE:
When a replacement EDK
is installed the adaptation
values of the previous EDK
must be cleared from the
ME 7.2 control module.
1. From the Service
Function Menu of the
DIS/MoDiC, clear
adaptation values.
2. Switch the ignition OFF
for 10 seconds.
3. Switch the ignition ON
(KL 15). At approxi-
mately 30 seconds the
EDK is briefly activated
allowing the ME 7.2 to
“electrically learn” the
new component.
This procedure is also necessary after replacing an ME 7.2 control module. However, the
adaptation values do not require clearing since they have not yet been established.

Functional Overview:
The DM-TL is located in the drivers side rear
wheel well in the X5.
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 restricter orifice (1.0
or 0.5 mm) which causes the electric motor to
draw a specific amperage value. This value is
equivalent to the size of the restricter.
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
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