Engine sensor connection BMW 528i 1998 E39 Workshop Manual

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Maintenance
< Release mass air flow sensor clips (A).
Release upper air filter housing clips (B).
4 Lift air filter upper housing, and remove filter element.
NOTE-
V-8 engine air filter assembly shown in illustration. 6-cylinder
air filter assembly is similar but located at the left front of the
engine compartment.
- On installation, install O-ring for mass air flow sensor into
retaining clips in air filter upper housing.
- Replace air filter and upper air filter housing, and attach
upper air filter housing clips.
Cooling system, checking
Antifreeze raises the boiling point and lowers the freezing
~oint of the coolant. BMW recommends enaine coolantthat is
a 50 150 mixture of distilled water and ethGene glycol-based
antifreeze.
Routine cooling system maintenance consists of maintaining
the coolant level and inspecting hoses. Because the coolant's
anticorrosion and antifreeze additives gradually lose their ef-
fectiveness, replacement of the coolant every three years is
recommended.
CAUJION-
Use only BMWapprovedphosphate-free antifreeze when
filing the cooling system. Use of antifreeze containing
phosphates is harmful to the cooling system.
4 Float in radiator tank indicates coolant level. Inspect while
coolant is cold.
When upper mark on float is level with top of filler neck,
coolant is at minimum allowable level.
When lower mark on float is level with top of filler neck,
coolant is at maximum level.
Hose connections should be tight and dry. Coolant seepage
nnection indicates either that hose clamp is

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I Engine Removal and Installation
WARNING -
Use extreme caution when draining and disposing of engine
coolant. Coolant is poisonous andlethal to humans andpets.
Pets are attracted to coolant because of its sweet smell and
taste. Seek medical attention immediately if coolant is ingest-
---
Working at rear of intake manifold:
Disconnect brake booster vacuum line (A).
Disconnect fuel tank vent line
(6).
Disconnect hoses (C and D) at coolant manifold
- Remove transmission harness support (E).
- Remove oil filter housing assembly from fender:
- Remove oil filter housing mounting fasteners.
Use stiff wire to secure oil filter housing to engine.
NOTE-
Do not disconnect oil lines from filter housing.
4 Disconnect supply and return fuel lines (where applicable) at
or near fuel rail. Plug open fuel lines.
NOTE-
BMW uses three styles of fuel line connections; a slngle use
clamp, a locking fitting that uses special tool
16 7 050 to re-
lease, and a
quiclc release sleeve (arrows) that disconnects
the line when depressed.
WARNING-
Fuel In fuel line is under pressure (approx. 3 - 5 bar or45 -
75 psi) and may be expelled. Do not smoke or worlc near
heaters or other fire hazards. Keep a fire extinguisher
handy. Before disconnecting fuel hoses, wrap a cloth
around fuel hoses to absorb any lealcing fuel. Catch and
dispose of escaped fuel. Plug all open fuel lines.
. Always unscrew the fuel tank cap to release pressure
in the tank before worlcing on the tank or lines.
< Remove air filter housing and mass air flow sensor:
Disconnect mass air flow sensor (A) and
intalte air temper-
ature sensor
(6) electrical harness connectors.
. Remove air filter housing mounting fastener (arrow).
Loosen intake hose clamp (C).
M62 engine: Remove hose at idle air stabilizer.
Remove air filter housing with mass air flow sensor.
Remove intalte hose from throttle body.

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11 0-20
Engine Removal and Installation
Working at right side of transmission bellhousing, disconnect
electrical harness connections (arrows) from starter. Re-
move starter retaining bolts and remove starter from trans-
mission mount.
M62 TU engine: Disconnect electrical harness connector
for right oxygen sensor from retaining clip and remove re-
taining clip from transmission.
- Working underneath engine compartment at left side:
Unclip positive battery cable from oil pan.
. Remove alternator cooling duct.
4 M62 engine: Remove fastener A and plug connector B from
alternator.
- M62 TU engine: Remove electrical harness connectors from
front of water cooled alternator.
- Remove exhaust system and transmission. See 180 Ex-
haust System and 230 Manual Transmission or 240 Auto-
matic Transmission.
- Working at front of engine:
Remove upper and lower hoses from radiator.
D~sconnect expansion tank hose from coolant pump.
- Remove belt-driven cooling fan:
Counterhold fan with special tool
11 5 050.
Turn fan mounting nut (32 mm) clockwise (left hand
threads) to loosen.
Rotate fan clockwise to remove.
Remove cooling fan shroud:
Disconnect electrical connectors from coolant level sensor
(B) and coolant temperature sensor (C).
. Remove expansion rivets (A) from each side of shroud
Remove coolant hose
(D).
Slide fan shroud with expansion tank up. Remove radiator
overflow tube from spout of expansion tank. Remove radi-
ator fan shroud with expansion tank.
Remove radiator. See
170 Radiator and Cooling System.

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113-10
Cylinder Head Removal and Installation
4 Working above engine, disconnect the following:
Vent line from cylinder head cover
(A).
. Oxygen sensor connectors (B).
Electrical harness connector from VANOS solenoid
valve
(C).
Electrical harness connectors at throttle valve position
switch
(D), ASC valve position switch (E), fuel injector har-
ness
(F) and vent valve (G).
CAUTION-
Be sure to mark oxygen sensor harness connectors so that
they can be reassembled correctly Do not interchange con-
nectors.
4 Where applicable, remove schraeder valve cap (arrow) from
air connection on fuel rail. Using a tire chuck, blow fuel back
through feed line using a brief burst of compressed air (max-
imum of
3 bar or 43.5 psi).
WARNING-
. Fuel in fuel line is underpressure (approx. 3 - 5 bar or 45 -
75 psi) and may be expelled. Do not smoke or work near
heaters or other fire hazards. Keep a fire extinguisher
handy Before disconnecting fuel hoses, wrap a cloth
around fuel hoses to absorb any leaking fuel. Catch and
dispose of escaped fuel. Plug open fuel lines.
- Always unscrew the fuel rank cap ro release pressure
;n the tank before working on the tank or lines.
Disconnect fuel lines by sliding locking collar in (arrows) and
pulling lines apart.
NOTE-
BMW uses three styles of fuel line connections; a one-time
use
clamp; a locking fitting that uses BMWspecial tool 16 1
050 to release; and a quick release sleeve (above) that dis-
connects the line when depressed.

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..
Cylinder Head Removal and Installation 1
< Remove intake throttle valve and ASC throttle assemblies:
Disconnect ASC throttle cable
(A).
- Remove ASC throttle housing mounting fasteners (B).
NOTE-
It is not necessary to disconnect coolant hoses (C) 01
bowden cables (D).
Remove intake throttle housing mounting hardware, pull
throttle housing off
intake manifold, and set aside.
- Working under intake manifold, disconnect the following:
Engine oil dipstick tube support.
Oil separator return line from dipstick tube.
Intake air temperature sensor electrical harness connector
(underside of intake manifold near throttle body).
* Fuel tank vent line and electrical harness at canister vent
valve.
Remove lower intake manifold supports (arrows).
- Disconnect coolant line retaining bracket at cylinder block.
4 Remove manifold mounting hardware (arrows).
- Remove intake manifold from cylinder head while carefully
checking for electrical connections or hoses.
NOTE-
Fuel rail is removed with intake manifold,
CAUTIOI\C
Stuff clean rags into open intake ports to prevent any parts
from falling into
Nie engine intake.
- Drain cooling system (engine block and radiator), then re-
move radiator cooling fan and fan shroud. See
170 Radiator
and Cooling System.
- Disconnect coolant hoses from thermostat housing.

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. .- -
Cylinder Head Removal and Installation
- Working at side of intake manifold near left strut tower, dis-
connect intake manifold resonance valve electrical harness
connector.
4 Disconnect fuel injector electrical harness connectors from
injectors.
- Use small screwdriver to pry out wire lock clip on fuel injec-
tor
1 connector.
Repeat for remaining injectors.
Release harness conduit fasteners from injector rail.
- Disconnect intake air temperature sensor electrical har-
ness connection (between intake runners for cylinders
3
and 4).
Lift off connector assembly and lay aside.
4 Where applicable, remove schraeder valve cap (arrow) from
fuel
ra~l. Using a tire chuck, blow fuel back through feed line
using a brief burst of compressed air (maximum of
3 bar or
43.5 psi).
WARNING-
Fuel is underpressure (approx. 3 - 5 bar or 45 - 75psi) and
may be expelled. Do not smoke or
work near heaters or
other fire hazards. Keep a fire extinguisher handy Before
d~sconnecting fuel hoses, wrap a cloth around fuel hoses
to absorb any leaking fuel. Catch and
dfspose of escaped
fuel. Plug all open fuel lines.
Always unscrew the fuel tank cap to release pressure
I in the tank before working on the tank or lines.
Disconnect manifold vacuum line (arrow)
Raise car and support in a safe manner,
CAUTION-
Make sure the car is stable and well supported at all times.
Use a professional automotive lift
orjack stands designed for
the purpose. A
floorjack is not adequate support.
Remove protective engine splash guard from below engine.

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Cylinder Head Removal and installation - - .- - - - -
4 Disconnect electrical harness connections at exhaust cam-
shaft position sensor and exhaust camshaft VANOS control
valve (arrows).
4 Remove banjo bolt from VANOS unit oil pressure line. Use
banjo bolt to attach
BMW special tool 11 3 450 (compressed
air fitting) to VANOS control unit.
CAUTIOI\C
Oil will drain from pressure line. Have a drain container and
rags ready Do not allow oil to run onto drive belts.
4 Cover oil hole (arrow) in VANOS unit with shop towel to cap-
ture oil which will spray when compressed air is applied.
- Connect compressed air line to air fitting. Apply air pressure
set to
2-8 bar (30-1 15 psi).
4 With compressed air line connected, rotate engine at vibra-
tion damper in direction of rotation (clockwise) at least twice,
until cylinder 1 intake and exhaust camshaft lobes face each
other (arrows) in the top dead center (TDC) position for cyl-
inder
1.
CAUTION--
Do not rotate engine counterclocltwise to reach the top dead
center position. If engine rotated beyond top dead center;
complete another two complete rotations.

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11 7-38
[Camshaft Timing Chain
4 Disconnect electrical harness connector (A), oil line fitting
(B), and cranltcase vent tube (squeeze at arrows).
NOJE-
Oil will drain from VANOS unit fitting. Use shop rags to keep
oil off drive belts.
- Remove cylinder head cover fasteners, and cover.
4 Remove oil baffle cover from intake camshaft
4 D~sconnect electrical connections from exhaust camshaft po-
sition sensor and VANOS control valve (arrows).
4 Using banjo bolt from VANOS control unit oil line, install test
fitting
(BMW special tool 11 3 450) to VANOS control unit.

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Fuel Injection
Warnings and cautions
For personal safety, as well as the protection of sensitive
electronic components, adhere to the warnings and cautions
on the following pages.
WARNING-
Gasoline is highly flammable and its vapors are explosive.
Do not smoke or work on a car near heaters or other fire
hazards when diagnosing and repairing fuel system prob-
lems. Have a fire extinguisher available in case of an emer-
gency
Renew fuel system hoses, clamps and O-rings any
time they are removed.
When working on an open fuel system, wear suitable
hand protection, as prolonged contact
with fuel can
cause illnesses and skin disorders.
* The ignition system produces high voltages that can be
fatal. Avoid contact with exposed terminals. Use ex-
treme caution when
working on a car with the ignition
switched on or the engine running.
CAUTION-
- Disconnecting the battery may erase fault code($ storedin
memory Check for fault codes prior to disconnecting the
battery cables. Read the battery disconnection cautions in
001 General Warnings and Cautions.
a Connect and disconnect the DME system wiring and
1 test equipment leads only when the ignition is switched
off.
Wait at least 1 minute after turning off the ignition be-
fore removing the engine control module (ECM) con-
nector. If the connector is removed before this time,
residualpower in the system relay may damage the
control module.
Fuel system cleaners and other chemical additives oth-
er than those specifically recommended by BMW may
damage the catalytic converter, the oxygen sensor or
other fuel supply components.
* Do not connect any test equipment that delivers a 12-
volt power supply to terminal 15 (+) of the ignition coil.
The current flow may damage the ECM. In general,
connect test equipment only as specified by BMW or
the equipment maker.
Only use a digital
multirneter for electrical tests. Only
use an LED test light for
quiclc tests.

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Fuel Injection I
Mass air flow (MAF) sensor,
checking and replacing
4 The hot film mass air flow (MAF) sensor (arrow) sends a
varying voltage (approx.
0.5 - 4.5 vdc) to the ECM represent-
ing the measured intake air. The air mass input signal is pro-
duced electronically by the
MAFsensorusing a heated metal
film in the air flow stream.
The ECM relay provides the operating voltage to the MAF
sensor. As air flows through the MAF sensor, the film is
-
cooled. To maintain the film at a constant temperature, addi-
tional heating current is necessary. It is this additional current
that is the basis for the input signal.
If there is no output signal from the MAF sensor, the ECM op-
erates the engine using throttle position and engine rpm in-
puts. A faulty MAF sensor illuminates the MIL.
A faulty MAF sensor can produce the following problems:
Difficult to restart when engine is hot.
Engine starts then stalls.
Engine starts and runs only with accelerator pedal de-
pressed.
Disconnect electrical harness connector from MAF sensor
(arrow).
- Turn ignition on and check for voltage and ground at connec-
tor.
There should be ground at pin
1 and battery voltage at pin
3.
If any faults are found, check for wiring breaks between
MAF sensor and ECM and between MAF sensor and ECM
relay.
NOTE-
Visually inspect the sensor for damage, missing or blocked
screens. The screens affect air flow calibration. Also inspect
the sealing O-rings where the sensor inserts into the air
filter
housing and intake boot. Ensure the pin connections are
clean and tight.
4 Connect a BMW-compatible scan tool or an OBD II generic
scan tool. Check air mass signal (load signal) with the engine
at idle. Raise idle speed and check that load signal changes
with rpm.
CA UTIOI\C
Be sure ignition is OFFbefore disconnecting or reconnecting r
1 DME svstem components. 1