2001 BMW 525i fuel injector wiring

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- .-
.. Cylinder Head Removal and Installation I -
< Disconnect the following electrical harness connectors:
Knock sensors
(A).
Thermostat (6).
Throttle position sensor and idle valve (C).
Camshaft position sensor (D).
Ignition coils (E).
< Remove mounting nuts (arrows) from wiring harness ducts.
4 Release fuel injector connectors by releasing spring clip
(arrow) on each injector.
Lift up and remove electrical ducts and set to one side

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11 6-9
Cvlinder Head and valvetrain1
4 Remove ignition coils and spark plugs.
V-8 models: remove mounting nuts (arrows) from wiring har-
ness ducting.
< V-8 models: disconnect fuel injector electrical connectors
from injectors:
Pry one corner of wire
loclc clip (arrow) on first injector.
Repeat for all injectors.
Lift wire ducts off and set aside.
- V-8 models: disconnect battery jump start post terminal from
left cylinder head cover.
- 6-cylinder models: remove oil filler cap and unclip vent con-
nection from cylinder head cover.
- Remove cylinder head cover mounting fasteners and re-
move cylinder head cover(~).
NOTE-
The cylinder head cover mounting bolt insulators and gas-
Icets should be reinstalled in their original locations. Make
note of their arrangement
during removal.

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Cylinder Head and Valvetrain
< Disconnect fuel injector electrical connectors from injectors.
Pry corner of wire lock clip (arrow) on first injector.
* Repeat for all injectors.
Lift wiring ducts off and set aside.
4 Remove right and left side ignition coil mounting nuts (ar-
rows) and coils.
NOTE-
Male note of location for ground straps (arrow A).
- Remove spark plugs.
- Disconnect positive (+)jumper junction from top of lefl cylin-
der head cover.
4 Remove retaining nuts (arrows) and remove oil lines from
left and right cylinder heads.

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1 17-68
Camshaft Timing Chain
4 Remove left and right side ignition coils and spark plugs:
- Remove positive (+) terminal cable from left cylinder head
cover.
- Unbolt lefl and right side cable ducts from fuel rail,
4 Disconnect fuel injector electrical connectors:
Pry corner of wire lock clip to release connector from injec-
tor
(arrow).
Repeat for all injectors.
Lift off wiring ducts.
4 Remove Fasteners (arrow) from lefl and right cylinder head
cover fasteners and remove covers.

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Camshaft Timing Chain LL. .- - - - I
4 Remove left and right side ignition coils and spark plugs:
- Disconnect electrical harness connectors at ignition coils
(A).
Remove left and right side ignition coil mounting fasteners
and coils.
NOTE-
Make note of location of ground strap (arrow).
Remove sparlc plugs.
- Remove positive (+) terminal cable from left cylinder head
cover.
- Unbolt cable ducts from fuel rail at left and right sides.
Disconnect fuel injector electrical connectors from injectors:
Pry corner of wire
loclc clip (arrow) to release connector.
Repeat for remaining injectors.
* Lift off wiring ducts.

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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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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.