1998 BMW 528i Engine sensor connection

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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

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Fuel Injection
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
4 Disconnect electrical harness connector from MAF sensor
(B).
- Turn ignition on and checlc 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, checlc for wiring breaks between
MAF sensor and ECM and between MAF sensor and main
DME relay.
NOTE-
Visually inspect the sensor for damage, missing or blocked
screens. The screens affect air flow calibration. Also inspect
the sealina
0-rinas 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 OED II generic
scan tool.
Checlc air mass signal (load signal) with the engine
at idle. Raise idle speed and
checlc that load signal changes
with rpm.
CAUTION-
Be sure ignition is OFFbefore disconnecting or reconnecting
DME system components.
Remove MAF sensor:
Loosen intake boot clamp
(A).
Disconnect harness connector (6).
* Release clip from air filter housing (C) and remove sensor.
- Installation is reverse of removal.
No adjustment to MAF sensor is possible.
Check intake hoses for cracks and vacuum
lealts.

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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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1 Exhaust ~vsteml
NOTE-
The front exhaust manifold must be removed before the rear
manifold.
- Installation is reverse of removal.
Coat exhaust mounting studs with CRC or equivalent cop-
per paste.
Use new gasltets and self-locking nuts.
Tightening torques Exhaust manifold to cylinder head 20 Nm
(15 ft-lb)
Front exhaust pipe to manifold 30 Nm
(22 ft-lb)
Oxygen sensor to manifold 50
Nrn (37 ft-lb)
Exhaust manifolds, removing and installing
(M62 engine)
Always use new retaining nuts and gasltets when removing
and installing the exhaust manifolds.
NOTE-
Access to manifolds is extremely limited. If removing exhaust
manifolds as part of additional engine worlc (such as cylinder
head removal), it may be easier to first remove engine.
- With exhaust system cold, raise and support car for access
to exhaust system.
WARNING -
Do not work undera lifted car unless it is solidly supported on
jaclt stands designed for the purpose. Never worlc undera car
that is supportedsolely
by a jack.
- Remove exhaust system. See Exhaust system, removing
and installing.
- Removing right side exhaust manifolds (cylinder bank 1-4):
Remove heat baffle plate.
Disconnect plug connection to oxygen sensor.
securing exhaust manifolds to head.
Remove manifolds towards bottom.
- Installation is the reverse of removal.
Coat exhaust mounting studs with CRC or equivalent
copper paste.
Use new gasltets and self-loclting nuts.

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Rear Suspension
- Remainder of installation is reverse of removal, noting the fol-
lowing.
Tighten suspension arm and shock absorber fasteners to
final torque only afler vehicle has been lowered and sus-
pension has settled.
Tightening torques
ABS pulse sensor to wheel bearing carrier 8
Nrn (6 ft-lb)
Air line connection 2 Nrn (18 in-lb)
Brake rotor to hub 16
Nrn (12 ft-lb)
Driveshaft
CV joint to final drive flange
- MI0 (Torx bolts) 70
Nrn (51 ft-lb)
- MB (compression nut) 32 Nrn (24 ft-lb)
Rear
brake pad carrier (caliper) to wheel 65
Nrn (48 ft-lb)
bearing carrier
Road wheel to hub
120ilO Nrn
(89 i-7 ft-lb)
Rear subframe mounting bushings,
removing and installing
- Remove rear subframe mounting bolts as described earlier.
Lower
subframe approximately 40 - 45 mm (1 -2 in).
4 Install BMW special tools 33 4 140,33 4 151,33 4 154,33 4
155,33 4 156 as shown.
Use hot air gun with a maximum output temperature of
600°C (1100" F) to heat bushing area of subframe for no
more than
2 minutes. Remove rubber mount from sub-
frame.
CAUTION-
Aluminum suspension parts may be severely damaged
witli intense heat
* Heating for 2 minutes with the recommended heat
source is intended to
keep the temperature of the alu-
minum
parts below the safety threshold of 80°C
(1 76°F). .

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4 INDEX
Door window anti-trap
512-4 convenience openinglclosing 512.4
regulator and motor 512-1 1
service
512-5 switches 512-3
see also Switches
Double
VANOS see VANOS
Drive
axle
CV joint 331-15 CV joint boot 331-15
rernovinglinstalling 331-14
Drive belt
see Maintenance
Driveabiiity troubleshooting
100-4
Driveaway protection
see EWS (eiectronic immobilization)
Driveshaft aligning
260-7
center bearing, replacing 260-12 CV joint, replacing 260-14
itex-disc, replacing 260-1 1
iront centering guide, replacing 260-13
rernovinglinstailing 260-6
lroubleshooting 260-3
U-joint 260-3
DSC
see Braires
DTC (diagnostic trouble code)
OBD-8
DWA
see Anti-theft alarm
ECM (engine control module)
see 130 under appropriate
iuei
injection system
ECT (engine coolant temperature)
sensor see 130 under appropriate
iuei
injection system
EDK adaptation
130-69
MS 43.0 130-35
EHC see Electronic iieigiit control (EHC)
Electric cooling fan
see Cooling system, cooling
fan
see also Cooiing system, eiectric fan
Electrical switches
see Switches
Electrical system abbreviations
600-14 bus System 600-4
component location table 610-3
components
photos
610-36
Sport Wagon 610-81 engine 121-2
troubleshooting 600-15
voltage and polarily 600-5 wire color codes 600-12
wiring diagrams 600-12
Electrical wiring diagrams
ELE-1
Eiectricaliy heated thermostat
(characteristic map)
170-4
Eiectronic height control (EHC)
300-8, 330-44
Eiectronic immobilization
see EWS (electronic immobilization)
Eiectronics box
(E-box)
610-37
Emergencies
010-18
Emergency brake see
BraBes, parking brake Engine
see also Cylinder head and valvetrain
applications
100-2
compression, testing 113-5
cooling see Cooiing system
crankshaft front oil seai
see Crankshaft oil seals
cyiinder leak-down test 113-8
diagnostic testing 113-1
drive belts
see Maintenance
driveability troubleshooting
100-4
engine management systems 100-2
see also Ignition
see also Fuel injection
fuel supply
130-6
ground connections 100-5
see also 61 0 identilying ieatures 100-3
lubrication svstem
see
~ubricetion system
mount
on-board diagnostics
OBD-I
oxygensensor
see Fuel injection
see also Exhaust system
Dreventive maintenance
see Maintenance
removal/installation
Engine control module (ECM)
see 130 under appropriate iuel
injection system
Engine cooiant temperature (ECT)
sensor see 130 under appropriate iuel
injection
system
Engine cooling fan
see Cooiing system, electric fan
Engine hood
41
0-6 raising to service position 410-6
Engine troubleshooting
see Engine, driveability troubleshooting
EVa~oratiVe control svstem
160-3 see also 130 under aDDroDriate iuel
injection system
Evaporator see
NC
Evaporator temperature sensor see
NC