service BMW 525i 2001 E39 Repair Manual

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Fuel Injection
of diagnostic time and to help avoid incorrect component re-
placement and possible damage to system components.
NOTE-
* Professional diagnostic scan tools available at the time of
this printing include the BMW factory tools and a small
number of aftermarket BMW-specific tools. The
CS2000
from Baum Tools Unlimited, the Retriever from Assenma-
chef Specialty Tools, and the MT2500 from Snap-on are
three examples.
In addition to the BMW-specific professional line of scan
tools, there are inexpensive generic OBD
I1 scan tool soft-
ware programs and
handheld units available. Although
these tools have limited capabilities as compared to the
dedicated tools, they are powerful diagnostic tools.
For the
DIY owner, simple aftermarltet DTC readeris avail-
able through
http://www.pealteresearch.com. This tool is
capable of checlting for
DTCs as well as turning off the il-
luminated
MIL and resetting the service indicator lights.
Tools and test equipment
If the equipment required to do the job is unavailable, it is rec-
ommended that these repairs be left to an authorized
BMW
dealer or other qualified BMW repair facility.
4 Low current test light ("noid")
(Tool No. Baum 11 15a)

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Fuel Injection I
- As an alternative, harness connector housing can be sepa-
rated so that electrical
checlts can be made from backof con-
nector.
4 If replacing ECM, disconnect control module harness con-
nector (arrow) by releasing fastener and pivoting connector
up and
off ECM.
CAUTION-
Be sure ignition is OFF before disconnecting or reconnecting
DME system components.
- Remove ECM from retaining brackets and lift off holder.
- Installation is reverse of removal.
- Before attempting to start engine, use BMW service tester
DISplus, MoDiC, GTI or equivalent:
- Code replacement ECM with application information (i.e.
engine code, transmission type, etc.).
Align ECM to EWS (electronic immobilizer).
Siemens MS 41.1 ECM pin assignments
ECM pin assignments are given in Table b. For engine man-
agement system schematics, see ELE Electrical Wiring
Di-
agrams.
CAUTION-
a Always wait at least one minute after turning off the ignition
before removing the connector from the
ECM. If the con-
nector is removed before this time, residual power
in the
system relay may damage the
ECM.
Always connect or disconnect the control module con-
nector and meter probes with the ignition
off
When malting checks at the ECM itself, a breakout box
should be used to allow tests to be made with the connector
attached to the ECM. This also prevents damage to the small
terminals in the connector. As an alternative, the harness
connector housing can be separated so that electrical checlts
can be made from the back of the connector.
Table b. Siemens MS
41.1 ECM pin assignments
Pin
1
2
3
4
Signal
output
output
output
qround Componenfffunction
Ignition coil control, cyl. 2
Ignition coil control, cyl. 4
ignition coil control, cyl. 6
Ground Notes
Primary signal,
ignition
coil 2
Primary signal, ignition coil 4
Primary signal, ignition coil 6
Ground

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Fuel Injection
4 Remove electrical harness connector (arrow) from IAT sen-
sor.
CAUTION-
Be sure the ignition switch is in the off position before repiac-
ins the intake temperature sensor.
- Depress loclting clip on side of temperature sensor and pull
straight out of intake manifold.
- Installation is reverse of removal
- Use a new sealing O-ring at base of sensor and lubricate with
assembly lubricant for
ease of installation
MS 42.0 throttle valve assembly, replacing
< The motor driven throttle valve for the MS 42.0 system is re-
- ferred to as MDK (motor driven throttle valve). The MDK unit
is electronically operated to regulate intake air flow by the
ECM.
The
MS 42.0 system uses a throttle cable from the accelera-
tor pedal to the MDK unit. The throttle cable is connected di-
rectly to the integral pedal position sensor
(PWG) in the MDK
unit. This sensor communicates pedal position to the ECM,
which in turn electronically regulates throttle plate position.
The MDK pulley is linked to the throttle shaft by springs to al-
low ASC intervention to override the driver's pedal position.
NO TE -
The MDIC unit is non-adjustable and must be replaced as
a complete unit if found to be faulty.
if replacing the
MDK unit, the adaptation values stored in
the ECM must be clearedand the new unit initialized using
BMW special service tools.
CAUTION-
If the adaptation process is not completed correct& the en-
gine wiii
not start.
- Disconnect battery negative (-) cable in luggage compart-
ment.
CAUTION-
Prior to disconnecting the battern read the battely discon-
nection cautions in
001 General Warnings and Cautions.

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Fuel Injection
MS 43.0 throttle valve assembly, replacing
The electronic throttle valve assembly forthe MS43.0 system
is referred to as
EDK (electronic throttle valve). There is no
mechanical (cable) link between the accelerator pedal and
the throttle plate.
< The accelerator pedal module (PWG) at the pedal assembly
communicates the pedal position directly to the ECM. The
module provides two variable voltage signals (via two Hail
sensors) to the ECM for pedal position and rate of movement.
NOTE-
The EDK unit is non-adjustable and must be replaced as a
complete unit if found to be faulty
If replacing the
EDK unit, the adaptation values stored in
the
ECM must be cleared and the new unit initialized using
BMW special service tools.
CAUTIOIG
If the adaptation process is not completed correctk the en-
qine will not start
- Disconnect battery negative (-) cable in luggage compart-
ment.
CAUTION-
Prior to disconnecting the battery, read the battery discon-
nection cautions given in
001 General Warnings and Cau-
tions.
< Remove complete air filter housing:
- Disconnect electrical harness connector on mass air flow
sensor
(A).
Disconnect vacuum line at intake boot (6).
Loosen intaite air duct clamp (C).
Remove filter housing mounting screws.
Disconnect air duct and lift complete air filter housing and
MAF sensor out of engine compartment, pulling it forward
away from throttle housing.

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130-38
Fuel Injection
Throttle cable, adjusting
(MS 42.0)
The throttle assembly on MS 42.0 cars uses a throttle cable.
The cable should be adjusted any time it is disconnected or
replaced. This procedure requires the factory scan tool or an
equivalent to read and adjust throttle angle. It is recommend-
ed the procedure be done by an authorized
BMW dealer ser-
vice department
Basic adjustment:
Ensure that at idle (accelerator pedal in rest position) throt-
tle cable has detectable play at throttle lever attaching
point. Play must not exceed maximum allowable.
Adjust by turning knurled adjuster
(arrow) on end of throt-
tle cable sheath at throttle housing.
NOTE-
Faulty throttle adjustment values must be reset using the
BMW service tester
DISplus, MoDiC, GTI or equivalent.
Max.
play at throttle plate lever
ldle speed control valve,
checking and replacing
3 mm (0.125 in)
The Idle speed control valve regulates Idle speed by red~rect-
ing air around the throttle valve. The ldle speed control valve
is mounted
d~rectly above the throttle housing. Accessing the
valve is best accomplished by
flrst removing the air fllter
housing and associated ducting.
Thevalve is supplied with batteryvoltage from the ECM relay.
The idle speed control valve incorporates a two-coil rotary ac-
tuator. The ground sides of each coil are pulsed simulta-
neously by the ECM. The duty cycle of each circuit is varied to
achieve the required idle speed.
A faulty idle speed control valve sets a fault code and the MIL
is illuminated when
OED II fault criteria are exceeded.
Before checking the idle speed control valve, confirm that the
throttle position sensor is working correctly.
- With engine running, check that idle speed control valve is
buzzing.
- Turn on AIC system or shift transmission into drive. ldle
should remain steady or increase slightly.
- If idle speed valve is not buzzing, or if idle decreases when
AIC is turned on, stop engine and disconnect harness con-
nector from idle speed valve.

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Fuel Injection I
Working inside E-box, disconnect ECM harness connector
(arrow) by releasing fastener and pivoting connector up and
off ECM.
CA UTIOW
Be sure ignition is OFF before disconnecting or reconnecting
DME system components.
Remove ECM from retaining brackets and lift off holder.
Installation is reverse of removal
Before attempting to start engine, use
BMW service tester
DISplus, MoDiC, GTl or equivalent:
* Code replacement ECM with application information (i.e
engine code, transmission type, etc.).
Align ECM to EWS (electronic immobilizer).
Siemens MS 42.0 and MS 43.0
ECM pin assignments
ECM pin assignments are given in Table c. For engine man-
agement system schematics, see
ELE Electrical Wiring Di-
agrams.
/ CAUTIOW I
Al~ays wait at least one mfnule after turning off the ignition
before
remov;ng [he connecror irom rhe ECM. If the con-
nector is removed before this time, residual power
in the
system relay may damage the
ECM.
Always connect or disconnect the control module con-
nector and meter probes with the ignition off.
When making checks at the ECM itself, a
breakout box
should be used to allow tests to be made with the connector
attached to the ECM. This also prevents damage to the small
terminals in the connector. As an alternative, the harness
connector housing can be separated so that electrical checks
can be made from the back of the connector.
Table
c. Siemens MS 42.0 and MS 43.0 ECM pin assignments
Pin
lslgnal l~om~onentlfunction 1 Notes
Connector
X60001 9-pin black
1 loutput I~erminai 15 I Unloeder relay terminal 15
2 I 1 Not used I
3 Not used
4 Ground
Ground Ground
point

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Fuel Injection I
The PWG potentiometers provide DC voltage signals as in-
put to the ME 7.2 control module for throttle and idle control
functions. Potentiometer signal
1 is the primary signal, poten-
tiometer 2 is used for a plausibility cross-check.
1. Potentiometer 1 ground
2. Potentiometer
1 power
3. Potentiometer 2 ground
4. Potentiometer 2 power
5. Potentiometer 1 signal to ECM
6. Potentiometer 2 signal to ECM
If errors are detected between potentiometer
1 and 2, the
ECM calculates the engine intake air mass (from
MAFsensor
signal) and only utilizes the potentiometer signal that closely
matches the detected
intake air mass. The ECM control mod-
ule uses the air mass signal for a comparative source to pro-
vide fail-safe operation.
If the ECM cannot calculate a
plausible conclusion from the monitored potentiometerthe
EDK motor is switched off and fuel injection cut-out is activat-
ed (no fail-safe operation possible).
EDK is continuously monitored during all phases of engine
operation. If faults are detected, the EDK motor is switched off
and fuel injection cut off is activated. The engine continues to
run extremely roughly at idle speed.
EDK adaptation
When the EDK throttle assembly is replaced, the adaptation
values of the previous EDK must be cleared from the ME 7.2
ECM using the BMW service testeroran equivalentscan tool.
Once the old adaptation values have been cleared, the new
EDK assembly should be installed and adapted as follows:
0 Switch ignition OFF for 10 seconds.
* Switch ignition ON. Afler approximately 30 seconds, the
EDK is briefly activated indicating that the replacement unit
is now adapted to the ME 7.2 system.
NOTE-
This EDK adaptation procedure is also necessary after re-
placing the
ME 7.2 engine control module. However, the ad-
aptation values do not require clearing since they have not
yet been established.
ECM relay, testing
The engine control module (ECM) relay is energized via the
ECM and supplies battery positive
(B+) power to many of the
engine management components and subsystems. If this re-
lay is faulty, the engine will not start.
NOTE-
The ECM relay is also referred to as the DME main relay

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This repair group covers service information specifically for the fuel supply system. Information on the fuel injection sys-
tem is covered in
130 Fuel Injection.
In the descriptions and procedures given below, engine and
engine management (DME) systems are referred to by man-
ufacturer code. If necessary, see
100 Engine-General for
model year, engine code, and DME applications.
NOTE-
Fuel filter replacement is covered in 020 Maintenance,
Special tools
Some of the procedures in this group require the use of
special tools.
I( Fuel line clamp 13 3 010 (Tool No. BMW 13 3 01 0)
4 Fuel pressure gauge T-fitting with shut-off valve
(Tool No. BMW 13
5 220)

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176 Radiator and Cooling System
General ........................... .I7 0.2
Special tools
........................ .I7 0.2
Cooling system overview
(M52 TU shown. others similar) ......... .I7 0.3
Coolant pump
....................... .I7 0.3
Thermostat
......................... .I7 0.3
Mechanical thermostat (M52 engine)
..... .I7 0.4
Electrically heated thermostat
.......... .I7 0.4
Radiator and expansion tank
........... .I7 0.4
Mechanical cooling fan with viscous clutch
.I7 0.4
Electric (auxiliary) cooling fan ........... .I7 0.4
Transmission fluid heat exchanger
....... .I7 0.5
Warnings and cautions
................ .I7 0.7
Troubleshooting ................... .I7 0.7
Cooling system inspection
............. .I7 0.8
Cooling system pressure test
........... .I7 0.9
Combustion chamber leak test
......... .I7 0.10
Thermostat
........................ .I7 0.1 0
Cooling System Service ........... 170-10
Coolant. draining and filling
(6-cylinder models)
.................. 170-1 0
Coolant. draining and filling (V-8 models)
. 170-12
Cooling system. bleeding
............. 170-14
Mechanical (viscous clutch) cooling fan.
removing and installing
............... 170-14
Electric cooling fan.
removing and installing
............... 170-15
Thermostat. removing and installing
(M52engine) ....................... 170-16
Thermostat. removing and installing
(M52 TU or M54 engine) .............. 170-17
Thermostat. removing and installing (V-8 models)
....................... 170-1 8
Coolant pump. replacing (6-cylinder models)
.................. 170-1 9
Coolant pump. replacing (V-8 models) ... 170-20
Radiator. removing and installing
....... 170-22
Expansion tank. removing and
installing . . 170-24

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The lubricant used varies, depending on transmission and
model year. Fluid application information is clearly marked on
a label on transmission.
On manual transmission, either ATF (orange label reads
ATF-Oil) or a special BMW lubricant (yellow label reads MTF-
LT
I) is used. See 230 Manual Transmission.
Automatic transmission is filled with either Dexron
Ill ATF
(black transmission ID plate reads ATF-Oil), or special life-
time oil (green transmission ID plate reads Life-Time Oil). See
240 Automatic Transmission.
CAUTION--
If in doubt as to the type of fluid installed in a particular trans-
mission, consult an authorized
BMW dealer service depari-
ment for the latest in operating fluids.