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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 lnjeciion
NOJE-
With engine oft disconnect harness connector and checlc
heating element resistance between white wires on the sen-
sor side of harness. If the element is electrically open (no
continuity), replace sensor.
- If oxygen sensor does not produce a fluctuating voltage and
preheater circuit is
OK, replace sensor.
NOJE-
If not already applied, coat oxygen sensor threads w~th anti-
seize compound before installat~on. Do not get the com-
pound on the sensor tip.
Tightening torque Oxygen sensor to exhaust system
55 Nm (41 ft-lb)
Fuel injectors, checking and replacing
The fuel iniectors are switched on and off (oaened and
closed)
by'the ECM. The injectors are connkcted to acom-
mon power source. A ground signal from the ECM is used to
open and close the injectors.
CA U JIOG
Use only a digital multimeter or an LED injector tester when
testing injectors or wiring. Use of an analog
VOM or incan-
descent test light may damaqe the engine controlmodule.
4 Remove fuel rail cover. See 110 Engine Removal and in-
stallation.
With the engine running, place the point of a long screwdriver
on each injector and check for a cliclting vibration.
If no vibra-
tion is found do the voltage
checit shown below.
Injector electrical loom removal:
- Loosen mounting nuts A.
Remove ground wire C.
Disconnect ignition coil harness D

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Fuel Injection
- If voltage is present as described above, check wiring be-
tween ECM and valve. If no wiring faults are found, check
ECM signal to valve.
- When replacing idle speed control valve, clean and inspect
all sealing areas.
. Inspect sealing ring in throttle body and replace if neces-
sary.
Throttle position sensor (TPS),
testing and replacing
The throttle position sensor (arrow) is mounted on the side
of the primary throttle housing and is directly connected to
the throttle valve shaft. The ECM sends a voltage signal to
the potentiometer-type sensor and monitors the voltage that
comes back. Resistance decreases (voltage increases) as
the throttle opens.
NOTE-
Do not confuse the TPS on the primary throttle housing with
the throttle switch on the
ASC secondary throttle housing.
4 Check throttle position sensor function by disconnecting har-
ness connector and checking across terminals. If any faults
are found, replace throttle position sensor.
Engine coolant temperature (ECT) sensor,
testing and replacing
Throttle position sensor (M62 engine)
The ECT sensor is located on the front of the engine in the
coolanVthermostat flange.The ECTsensor is a dual tempera-
ture sensor. One circuit provides coolant temperature infor-
mation to the ECM while the other circuit provides coolant
temperature information to the instrument cluster.
The ECM determines the correct ignition timing and
airlfuel
mixture required for the engine by monitoring an applied volt-
age
(5 vdc) to the sensor. The voltage drop across the sensor
Test
value
5 vdc (approx.)
4.0 kR(approx.)
Continuously variable
from
1.0 to 4.0 kR
without interruption
Test
conditions
Harness connector
disconnected, ignition on
Harness connector
disconnected,
ignition on
Throttle plate rotated from idle to
full throttle position Test Terminal
Term.
1 at
harness
connector and ground
Term.
1 and term. 3 at
sensor
Term.
1 and term. 2 at
sensor

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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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Steering and Wheel ~li~nrnentl
q Pry gently to detach flexible cover from upper trim. Lift off
trim.
< Remove lower dash trim panel fasteners (A) and (B).
Lower trim panel and disconnect wiring harnesses on back
side of panel.
Remove trim panel.
- Installation is reverse of removal.
Ignition switch ring antenna (EWS),
removing and installing
- Remove upper and lower steering column trim as described
earlier.
- Disconnect electrical harness plug from ring antenna.
- Use flat side of BMW special tool 61 3 300 to pry ring antenna
off ignition lock cylinder.
- Installation is reverse of removal.
lgnition lock cylinder, removing and
installing
- Disconnect negative (-) cable from battery.
CAUTION-
Prior to disconnecting the battery, read the battery discon-
nection cautions given
in 001 General Cautions and
Warnings.
- Remove upper and lower steering column trim as described
earlier.

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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