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.-
ignition System
Disabling ignition system
The ignition system operates in a lethal voltage range and
should be disabled any time engine service or repair work is
being done that requires the ignition to be switched on.
The engine management system can be disabled by remov-
ing the DME main relay. The relay is located in the electronics
box (E-box) in the left rear of the engine
compartment, be.
neath the interior microfilter housing.
CAUTION- Relay locations may
vary. Use care when identifying relays.
See
610 Electrical Component Locations.
Checking for spark
CAUTION-
If
a spark test is done incorrecth damage to the Engine Con-
trol Module
(ECM) or the ignition coils may result.
NOTE-
Spark plug replacement is covered in 020 Maintenance.
Check~ng for spark is d~fflcult on englnes wlth d~str~butorless
ignition systems.
Try removing the spark plugs and inspecting for differences between them.
A poor-firing plug may be wet with fuel and/or ~. - ~
black and sooty, but not always. If a coil is not operating, the
engine management system will electrically disable the fuel
injector to that cylinder. The key is to look for differences be-
tween cylinders.
Ignition coil assembly, testing and
replacing
C4 UTION-
Use a digital multimeter for the following tests. I
- Remove plastic engine cover from top of valve cover by pry-
ing off bolt covers and removing cover mounting bolts.
- Raise car slowly while constantly checking position of jack
and car.
- Disconnect harness connector from coil. Connect multimeter
between terminal 15
(+) in connector and ground.
4 Terminal identification are typically molded into connector. In
photo, terminals are from left to right: 1,
4a, 15.
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I Ignition System
Camshaft position sensors
The camshaft position sensors are used by the englne man-
agement system for VANOS control, sequential fuel injection
and knock control.
Intake camshaft position sensor, replacing
(M52,M52 TU
and M54 engines)
- Make certain ignition has been turned off.
- Remove plastic cover from above fuel injectors by prying off
bolt covers and removing cover mounting bolts.
Remove complete air filter housing:
Disconnect electrical harness connector on mass air flow
sensor
(A).
Detach vacuum line at intake boot (B).
Loosen hose clamp at intake boot and detach air duct con-
nections
(C).
* Disconnect cold air duct tube (D).
Remove filter housing mounting screws (E).
- Disconnect harness connector from VANOS solenoid and
unscrew solenoid from VANOS control unit. Be prepared with
shop rags to catch oil released from VANOS unit.
Remove camshaft sensor (arrow) from
left front of cyl~nder
head, next to top of oil filter housing.
Disconnect camshaft sensor harness from under intake
manifold. Prior to removal, attach a stiff piece of wire to the
harness connector end to preserve proper routing of harness
for reinstallation.
Installation is reverse of removal, noting the following:
Use new O-rings when installing sensor and solenoid.
Be sure wiring is rerouted in same orientation.
Use scan tool to read out and clear
ECM fault memory
Tightening torques
-
Intake camshaft sensor to cylinder head 10 Nrn (7 ft-lb)
VANOS solenoid to VANOS control unit 30 Nm (22 ft-lb)
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130-1
130 Fuel injection
General ........................... .I3 0.2
Tools and test equipment .............. .I3 0.3
Warnings and cautions ................ .I3 0.5
Fuel Supply ....................... .I3 0.6
Relieving system fuel pressure .......... .I3 0.6
Siemens MS 41 . 1. ................... 1 30-7
ECM relay. testing .................... .I3 0.7
Mass air flow (MAF) sensor.
checking and replacing
................ .I3 0.9
Engine coolant temperature (ECT) sensor.
testing and replacing
.................. 130-10
Intake air temperature (IAT) sensor.
testing and replacing
................. .I3 0.1 1
Throttle position sensor (TPS).
testing and replacing
.................. 130-1 2
ldle speed control valve.
checking and replacing
............... .I3 0.1 3
Fuel injectors. checking and replacing .... 130-15
Evaporative emissions. overview ....... .I3 0.1 6
Secondary air injection. overview ....... .I3 0-17
Engine control module (ECM).
removing and installing
................ 130-18
Siemens MS 41.1 ECM pin assignments . .I3 0.19
Siemens MS 42.0 and MS 43.0. ..... .I3 0.23
ECM relay. testing ................... .I3 0.27
Mass air flow (MAF) sensor.
checking and replacing
............... .I3 0.28
Engine coolant temperature (ECT) sensor.
testing and replacing
................. .I3 0.30
Intake air temperature (IAT) sensor.
testing and replacing
................. .I3 0.31
MS 42.0 throttle valve assembly. replacing . 130-32
MS 43.0 throttle valve assembly. replacing . 130-35
Throttle cable. adjusting (MS 42.0) ...... .I3 0.38
ldle speed control valve. checking
and replacing
....................... .I3 0.38
Evaporative emissions control diagrams . . 130- 39
Evaporative emissions control.
(MS
42.0 and MS 43.0). .............. .I3 0.39
Engine control module (ECM).
removing and installing
................ 130-40
Siemens MS 42.0 and MS 43.0
ECM pin assignments ................. 130-41
Bosch M5.2 (M62 up to 911997)
BOSC~ M5.2.1 (M62 911997 to 911998) 130-46
M5.2 system features ................. 130-47
M5.2.1 system features ............... 130-47
ECM relay. testing ................... 130-49
Oxygen sensors. checking ............. 130-51
Fuel injectors. checking and replacing .... 130-52
Mass air flow (MAF) sensor. replacing .... 130-53
ldle speed control valve. testing
and replacing
....................... 130-54
Throttle position sensor (TPS).
testing and replacing
................. 130-55
Engine coolant temperature (ECT) sensor.
testing and replacing
................. 130-55
Intake air temperature (IAT) sensor.
testing and replacing
................. 130-57
Auxiliary throttle valve (ADS) (M62 and
M62 TU engine). replacing ..... 130-57
Evaporative system pressure
leak diagnosis. overview
(5.2.1 only) ..... 130-58
Bosch 5.2 ECM pin assignments
(M62 UP to 911 997) ................... 130-59
~osch 5.2.1 ECM pin assignments
(M62 911 997 to 911 998) ............... 130-62
BOSC~ ME 7.2 ..................... 1 30-66
ME 7.2 system overview ............... 130-67
EDK adaptation ..................... 130-69
ECM relay. checking .................. 130-69
Engine coolant temperature
(ECT) sensor. testing
................. 130-71
Engine coolant temperature
(ECT) sensor. replacing
............... 130-71
Oxygen sensors. replacing ............. 130-72
Fuel injectors. removing and installing .... 130-72
Mass air flow (MAF) sensor.
removing and installing
................ 130-73
Evaporative system pressure
leak diagnosis. overview
............... 130-74
Secondary air injection. overview ........ 130-75
Bosch ME 7.2 ECM pin assignments .... 130-76
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Fuel injectors, checking and replacing
The fuel injectors are electronically controlled solenoid valves
that provide precisely metered and atomized fuel into the en-
gine intake ports.
The injectors receive voltage from the ECM relay. The ECM
controls the opening by activating the ground circuit
forthe in-
jector valve solenoids. The ECM varies the duration (in milli-
seconds) of "opening" time to regulate the
airlfuel ratio.
For a quick
check of the injectors, run the engine and touch
each injector with a screwdriver or stethoscope. You should
feel a vibration or hear a buzzing
Remove fuel injection harness from injectors by unclipping
locking clip at each injector. Lift harness off injectors.
CA U JIOG
Be sure ignition is OFF before disconnecting or reconnecting
DME system components.
Use a multimeter to test injector coil resistance between in-
jector terminals.
l~uel injector coil resistance 16R at 20" C (68" F)
Disconnect negative
(-) battery cable
CAUTIOG
Prior to disconnecting the battery, read the battery discon-
nection cautionsgiven
in 001 General Warnings and Cau-
tions.
4 Remove plastic trim plugs (arrows) and fasteners, then re.
move cover from above fuel injectors.
- Disconnect vacuum line from fuel pressure regulator.
- Remove wiring harness duct mounting fasteners.
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I Fuel Injection
Release injector locking clips at each injector and pry injector
wiring duct up off injectors.
Clamp off fuel supply line and fuel return line at end of fuel
rail. Disconnect fuel supply fuel return lines from fuel rail.
WARNING -
Clamp off the fuel lines and then wrap a clean shop towel
around the lines before removing them. Residual
fuelpres-
sure is present in the lines.
Fuel is discharged. Do not disconnect any wires that
could cause electrical
sparks. Do not smoke or work
near heaters or other fire hazards. Keep an approved
I fire extinguisher handy. I
- Remove fuel rail mounting fasteners
- Pull up on fuel rail and remove individual injectors by remov-
ing injector retaining clip and pulling injector from rail.
- Installation is reverse of removal. Fit new O-rings when in-
stalling injectors. For ease of installation, lightly lubricate in-
jector O-ring with
SAE9O gear lube.
Tightening torque Fuel rail to
intake manifold 10 Nm (89 in-lb)
Evaporative emissions, overview
On E39 MS 41 .I cars, the evaporative emissions system is
combined with the tank ventilation system. The evaporative
system is monitored by the ECM for correct purge operation
and leak detection.
The carbon (purge) canister is purged using engine vacuum
via the
purgevalve.The purgevalve (located nextto the mass
airflow sensor) is ECM controlled and regulates the purge
flow into the intake manifold. The valve is powered open and
closed by an internal spring.
If the evaporative emission valve circuit is faulty, a fault code
is set and the MIL is illuminated when OBD
II fault criteria are
exceeded. If the valve is mechanically faulty, poor driveability
may result and a mixture adaptation fault is stored in the
ECM.
The leak diagnosis pump (LDP) is activated by the ECM and
pressurizes the fuel tank and evaporative system as apart of
theOED I1 leakdetection monitor. If the LDP orthe LDP circuit
is defective, afault code is set and the MIL is illuminated when
OBD
I1 fault criteria are exceeded. The LDP is mounted the
left rear wheel well behind the fender liner.
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130-1 8
1 Fuel injection Secondary air injection
1. Secondary air pump (in right
front wheel housing)
2. Secondary air vacuum vent
valve solenoid (on intake mani-
fold)
3. Secondary air check valve
4. Intake manifold
5. Exhaust manifolds
6. Diverter valve (at exhaust mani-
fold)
Engine control module (ECM),
removing and installing
The ECM uses stored functions and processing programs to
process the input signals from the sensors. These input sig-
nals are used to calculate the control (output) signals to the
actuators
(e.g., ignition coils, injectors).
NOTE-
Consult an authorized BMW dealer before replacing the
ECM.
- Disconnect negative (-) battery cable. Wait approximately
one minute.
Prior to disconnecting the
battely, read the battery discon-
nection cautions in
001 General Warnings and Cautions.
Access engine control module (ECM):
Release interior ventilation filter cover latch
(A) and re-
move cover.
Release plastic locking tab
(B).
Rotate air duct inward (arrow) to unloclc from bulk head
and remove duct.
Release spring lock
(C) to remove lower filter housing.
Slide filter housing away from inner fender to remove.
- Remove electrical box (E-box) cover fasteners and remove
cover.
- If testing ECM or connected components, use breakout box
to allow tests to be made with connector attached to the
ECM. This prevents damage to small terminals in connector.
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I Fuel Injection
Table b. Siemens MS 41.1 ECM pin assignments (continued)
Pin
l~iqnal I Componentlfunction 1 Notes I - I I
5 loutput I Fuel injector control, cyl. 2 I Pulsed ground (pulse width in ms), cyl. 2 I I I
6 loutput /Fuel injector control, cyi. 1 I Pulsed ground (pulse width in ms), cyl. 1
I I I
14 linput I Intake air temp. sensor (IAT) I Intake air temperature signal
- 7
8
9
10
11
12
13
ground
input
output
input
input
15
16
17 18
19
20
21
22
I - I I
35 loutput /Secondary air injection ISecondary air inj. pump relay control
25
26
27
28
29
30
31
32
33
36
/output I Engine speed output IEngine speed signal
Mass air flow sensor
Mass air flow sensor
instrument cluster
Engine coolant
temp.
(ECT) sensor
Not used
Throttle position sensor (TPS)
Not used
input
input
input
input
output
output
out~ut
37 1 - /Not used I
Mass air flow sensor signal
Mass air flow sensor signal
Fuel consumption signal
ECT signal
Throttle position signal
ground
input
output
ground
output
output
output
ground
output
Traction control (rear engine speed signal) Automatic climate control
Not used Electronic immobilizer control (EWS)
Auto. climate control
(AIC on input)
instrument
cluster
Camshaft actuator control (VANOS)
Fuel iniector control, cvl.
3
AES/ASC module
Automatic climate control instrument cluster (CARE signal)
Camshaft actuator (VANOS), switched ground
Pulsed ground (pulse width in
ms), cyl. 3
Oxygen sensor heater (no. 1 in front of catalytic
converter)
Power supply (terminal
30)
Idle speed control valve
Ground
Ignition coil control, cyl.
1
Ignition coil control, cyl. 3
Ignition coil control, cyl. 5
Ground Fuel injector control, cyl.
5
Oxygen sensor heater ground
Battery voltage
(E+) at all times
Pulsed ground-open signal (See pin
53)
Ground
Primary signal, ignition coil
1
Primary signal, ignition coil 3
Primary signal, ignition coil 5
Ground
Pulsed ground (pulse width in ms), cyl
5
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130-40
Fuel Injection
Engine control module (ECM),
removing and installing
The ECM uses stored functions and processing programs to
process the input signals from the sensors. These input sig-
nals are used to calculate the control (output) signals to the
actuators
(e.g., ignition coils, injectors).
NOTE-
Consult an authorized BMW dealer before replacing the
ECM.
- Disconnect negative (-) battery cable. Wait approximately
one minute.
CAUTION-
Prior to disconnecting the batteg read the battery discon-
nection cautions
in 001 General Warnings and Cautions.
4 Access engine control module (ECM):
Release
interlor ventilation filter cover latch (A) and re-
move cover.
Release plastic loclting tab
(B).
Rotate air duct inward (arrow) to unloclt from bulk head
and remove duct.
Release spring lock
(C) to remove lower filter housing.
Slide
f~lter hous~ng away from inner fender to remove.
- Remove electrical box (E-box) cover fasteners and remove
cover.
- If testing ECM or connected components, use breakout box
to allow tests to be made with connector attached to ECM.
This prevents damage to small terminals in connector.
- - As an alternative, harness connector housing can be sepa-
rated so that electrical checks can be made from
back of con-
nector.
4 If replacing ECM, disconnect control module harness con-
nector (arrow) by releasing fastener and pivoting connector
up and off ECM.