1999 BMW 540i lock

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Fuel lniection I
4 Remove complete air filter housing:
Disconnect electrical harness connector on mass air flow
sensor
(A).
Disconnect vacuum line at intake boot (B).
Loosen Intake 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.
- Pull throttle cable upwards out of rubber retainer and unhoolc
ball end of cable from throttle actuator.
4 Remove nuts and bolts (arrows) retaining wiring harness to
throttle housing.
- Working at throttle housing, turn harness plug counterclock-
wise and remove plug.
4 Working at side of intake manifold, disconnect electrical har-
ness connectors:
Idle control valve (A)
lntalce manifold resonance valve (B)
- Disconnect electrical harness connectors at oil pressure
sender and oil temperature sender at base of oil filter hous-
ing.
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/Fuel Injection
4 Remove dipstick guide tube:
Disconnect wiring harness brackets from tube (A).
Unclip fuel lines from dipstick tube
(El).
Remove lower guide tube mounting bolt (C). Pull out dip-
stick guide tube.
< If necessary, disconnect electrical harness connector at fuel
tank venting valve (A). Disconnect hose at quick disconnect
fitting (arrow).
Working at throttle housing, turn harness plug counterclock-
wise and disconnect. Remove throttle assembly mounting
fasteners (arrows) and pull assembly off manifold.
Installation is reverse of removal
Replace sealing ring between throttle assembly and intake
manifold.
0 Reattach throttle assembly harness connector with care.
Arrow on fully tightened connector must line up with corre-
sponding arrow on throttle assembly housing.
* Connect BMW test equipment or equivalent and carry out
throttle plate adaptation following the on-screen directions.
Reattach throttle cable and check cable adjustment as de-
scribed under Throttle cable, adjusting
(MS 42.0).

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-.
Fuel Injection 1
4 If necessary, disconnect electrical harness connector at fuel
tank venting valve (A). Disconnect hose at quick disconnect
fitting
(arrow).
< Worlting at throttle housing, turn harness plug counterclock-
wise and disconnect. Remove throttle assembly mounting
fasteners
(arrows) and pull assembly off manifold.
- Installation is reverse of removal.
0 Replace sealing ring between throttle assembly and intake
manifold.
Reattach throttle assembly harness connector with care.
0 Arrow on fully tightened connector must line up with corre-
sponding arrow on throttle assembly housing.
- Use BMW scan tool to reset ECM adaptation values.

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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.

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- Fuel Injection
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.
CAUTIOI\C
Relay positions can vary. Be sure to confirm relay position by
identifying the wiring
in the socket using the wiring diagrams
in ELE Electrical Wiring Diagrams.
NOTE-
The ECM relay is also referred to as the DME main relay.
ECM relay powers:
* ECM
Ignition coils
Fuel injection
Evaporative leak detection pump
(5.2.1 only)
Idle air actuator
Camshaft sensors Evaporative emissions valve
Hot film mass air flow sensor
Fuel pump relay
Oxygen sensor heaters
4 Working in right rear of engine compartment:
Release interior ventilation filter cover latch
(A) and re-
move cover.
Release plastic locking tab
(B).
Rotate duct inward (arrow) to unloclc from bulk head and
remove duct.
0 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.

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Fuel Injection I
4 Release spring clips (arrows) from fuel injectors and pull in-
jector electrical loom straight up to remove.
4 Check that ECM signal is present at injector connectors.
- Connect digital voltmeter to fuel injector harness plug.
Operate starter and
check for voltage pulse.
* Repeat for each injector.
- Remove fuel injectors by removing retaining clips
- Installation is reverse of removal:
Fit new O-rings when installing injectors. For ease of instal-
lation, lightly lubricate all fuel system O-rings with assem-
bly lubricant.
Check that injector electrical connections are correctly fit-
ted and that
injectors are fully seated prior to installing iuel
rail mounting bolts.
Mass air flow sensor (MAF), replacing
The MAF sensor is provided with operating power from the
ECM relay. Based on calculated intake air mass, the MAF
generates
avarying voltage (approx. 0.5 - 4.5 vdc) as an input
signal to the ECM.
4 Remove MAF sensor:
Remove upper air filter housing locking clips.
Unscrew and remove MAF sensor harness
(A).
Disconnect intake air temperature sensor harness (B).
Loosen hose clamp (C).
Remove upper filter housing with sensor.
- Installation is reverse of removal

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130-70
Fuel Injection
ECM relay
--
CAUTION-
Relay positions can vary Be sure to confirm relay position by
identifying the wiring in the
socl(et using the wiring diagrams
in ELE Electrical Wiring Diagrams.
Working in right rear of engine compartment:
Release interior ventilation filter cover latch
(A) and re-
move cover.
Release plastic locking tab
(B).
Rotate duct inward (arrow) to unlock from bulk head and
remove duct.
Release spring
loclt (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.
4 With ignition off, remove main relay (arrow) in electronics
box (E-box) at right rear of engine compartment.
NOTE-
Relay locations can vary Confirm relay identification by
matching wiring colors and terminal numbers.
4 Check for voltage at terminal 6 of main relay socket (30-red
wire).
If battery voltage is present, continue testing.
If battery voltage is not present, check large red wire in re-
lay socltet. See ELE Electrical Wiring Diagrams.
- Reinstall relay and turn ignition on. Gain access to underside
of relay socket and check for ground at terminal
4 (85-brown
wire).
If ground is present, continue testing.
If ground is not present, switched ground signal from ECM
is missing. Check wire between ECM and relay.
- With ignition on and relay installed, check for battery voltage
at terminal
2 (87-redlwhite wire).
If battery voltage is present, relay has energized and is
functioning correctly.
If battery voltage is not present and all earlier tests are OK.
relay is faulty and should be replaced.

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( Mass Air Flow Sensor
1" Intake air temp. (NTC)
Sensor qround
Reference voltage . . . -., f fitr mass signal I
Fuel Injection I
Release fuel injector locking clips (arrow).
- Remove fuel injector loom boxes and lay to one side.
- Remove 4 fuel rail mounting fasteners.
4 Disconnect fuel line at quick-disconnect. To disconnect,
press in plastic collar (arrow) and separate fuel line.
WARNING -
Fuel may be expelled underpressure. Do not srnol(e or work
near heaters or
other fire hazards. Keep a fire extinguisher
handy. Before disconnecting fuel hoses, wrap a cloth around
fuel hose
to absorb anv leakinq fuel. Plug all open fuel lines.
- Lifl fuel rail and injectors straight up to remove.
- lnstallation is reverse of removal. Use new injector seals and
clamps during installation.
Mass air flow (MAF) sensor,
removing and installing
4 The MAF sensor is provided with operating power from the
ECM relay. Based on intake air mass, the MAF sensor gen-
erates a varying voltage (approx. 0.5
- 4.5 vdc) as an input
signal
back to the ECM. A separate intalte air temperature
sensor is not used.
- Removing MAF sensor:
Remove upper air filter housing locking clips
Unscrew and remove sensor harness.
Disconnect air temperature sensor harness.
Loosen hose clamp.
Remove upper filter housing with sensor.
- lnstallation is reverse of removal