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Fuel Injection
Table c. Siemens MS 42.0 and MS 43.0 ECM pin assignments (continued)
Pin
42
43
44
45
46
47
48
49 50
51
52 Componentlfunction
Signal, evaporative emissions valve
Signal, throttle
valve drive
Signal, throttle valve drive
Signal, engine coolant thermostat
Signal, close idle speed control valve
Signal, open idle speed control valve
Signal, shield
ltnock sensor
Signal, resonance valve
intake system
Not used
Not used
Signal, secondary air injection pump valve
Signal
Input
Input
Input
Input
input
Input
Ground
Input
Input
Notes
Evaporative emissions valve
Throttle valve
Throttle valve Engine coolant thermostat (map controlled)
idle speed control valve
Idle speed control valve
Shield,
knock sensor
Resonance valve intake system
Secondary air injection valve
Connector
X60004 40-pin Notes
instrument cluster control unit
Instrument cluster control module
Secondary air injection pump relay
Electric (auxiliary) fan motor
Pedal position sensor (PWG) (MS 43.0)
Pedal position sensor (PWG) (MS 43.0)
Pedal position sensor (PWG) (MS 43.0)
Fuel pump relay
1
Instrument cluster control module
ComponenVfunction
Signal, battery charge indicator lamp
Feedback signal, engine start
Signal, secondary air injection pump
Signal, electric cooling fan
Not used
Not used
Pedal position sensor (PWG) (MS 43.0)
Signal, pedal position sensor (PWG) (MS 43.0)
Pedal position sensor (PWG) (MS 43.0)
Signal,
fuel pump relay 1
Signal, oil pressure switch
Pin
1
2 3
4
5
6
7
8
9
10
11 Signal
Input
Input
input
input
Input
Input

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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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Fuel Injection Evaporative fuel system pressure leak
diagnosis, overview
(M5.2.1 only)
1998 540i models are equipped with an evaporative fuel sys-
tem pressure leak diagnosis system. The main component of
this system is the leak diagnosis pump (LDP). The function of
the LDP is to pressurize the fuel tank and the evaporative
emission system for the purpose of detecting
leaks. This sys-
tem is capable of detecting a leak as small as 0.5 mm.
The LDP, located in the left rear wheel housing, is a unitized
component that contains the following:
Vacuum chamber. Pneumatic pump chamber.
DME activated vacuum solenoid
Reed switch (provides switched voltage
feedback signal to
ECM).
The vacuum supply line is in the wiring harness from the en-
gine compartment and runs down the driver's side of the vehi-
cle.
The canister vent valve is integrated into the LDP, which is
electrically controlled by the ECM. The canister vent valve is
opened to provide fresh air entry into the fuel system only dur-
ing purge operation.
- Purge operation characteristics:
Off idle through full throttle: purge valve opened by pulse
width modulated (PWM) control of the ECM. PWM duty cy-
cle varies by engine operating conditions
(e.g. warm idle,
purge valve opened slightly; cold
idleldecel with engine
temp
< 67" C, purge valve always closed).

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130-60
/Fuel lniection
Tabled. Bosch M5.2 ECM pin assignments
Note
Pin
21
20 I output / Crankshaft position sensor (speed and position) I Crankshaft positionlrpm sensor
23
I - I I 29 1 output I Idle speed control - opening winding I Idle speed control valve (cycled ground)
Type
22
1 output I Cvl. 6 ignition signal (primary signal) I Cyl. 6 ignition coil (RZV adapter)
output
25
26
27
28
Component/function
24 1 outout I Cvl. 7 iqnition siqnal (primary signal) I Cyl. 7 ignition coil (RZV adapter)
output
4 outbut I' I - I Cyl. 3
fuel injection valve I Cyl. 3 fuel injection valve (cycled ground)
Camshaft position
sensor (cylinder reference)
output input
output
oround
30
31
32
ground Hall effect camshaft position sensor
Cyl. 3 ignition signal (primary signal)
output
I
Cyl. 3 ignition coil (RZV adapter)
. - . .. . .
Cyl. 2 ignition signal (primary signal)
Terminal 30
Engine control module relay
Ground for electronics and sensor shield
output
output
outout
Remaining output stages ground
(not iclnition and fuel iniection valves) Cyl.
2 ignition coil (RZV adapter)
Fuse carrier, engine electronics
Engine control module relay
Ground splice ,
Cyl. 2 fuel injection valve
Oxygen sensor heater signal
Cyl. 5
fuel injection valve
Cvl. 8 fuel iniection valve
AIC comuressor relav sianal
Heated oxygen sensor I in front of catalytic converter,
Heated oxygen sensor
iI in front of catalytic converter
Cyl.
5 fuel injection valve (cycled ground)
Cvl. 8 fuel iniection valve (cycled ground)
. -
Not used Ground point
Cyl.
2 fuel injection valve (cycled ground)
Heatinq and AIC control module (ground - compressor OFF)
38 Not used
40 39
1 I Not used
I'
I . I
I' I -. I
46 1 ground I Heated oxygen sensor signal (voltage 0.1-1.0 V) I Oxygen sensors
41
1 inuut I Knock
sensor signal I Knock sensor
input
I
I I
Instrument cluster
I' I I 55 1 ground I Ignition ground I Ground point
Knock sensor signal
43
1 I Not used I
Fuel reserve signal
42
Throttle position sensor
47
48
49
50
51
52
53
54
Knoclc sensor
input
45
1 outout I Hot film mass air flow sensor signal (0-5 V) I Hot film mass air flow sensor
Throttle position sensor signal
(0.4-4.2 V) 44
input
output
output
output
output
output
inout
I - I
Not used
Not used
Cyl. 1 ignition signal (primary signal)
Cyl. 5 ignition signal (primary signal)
Cyl. 4 ignition signal (primary signal)
Cyl. 8 ignition signal (primary signal)
Throttle position sensor
(c 5 V voltage supply)
Terminal 87
f> 10 V)
ignition switch
56
Cyl. 1 ignition coil (RZV adapter)
Cyi. 5 ignition coil (RZV adapter)
Cyi.
4ignition coil (RZV adapter)
Cyl. 8 ignition coil (RZV adapter)
Throttle position sensor
Fuse
F1
input Terminal 15 (> 10 V)

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-
Fuel Injection
Table e. Bosch 5.2.1 ECM pin assignments
Pin
I~iqnal 1 Description 1 Note
I I I
46 llnput ICrankshaft position sensor Icrankshaft positionlrpm sensor
38
39
40
41
42
43
44
45 Ground Input
Output
Output
Output
Output
Ground
47
48
49
50
51
Not used
I Not used
52
Shield, knock sensor
Oil level
- thermal
Injection signal
injection signal
Idle speed control - opening winding
Idle speed control - closing winding
Not used
Ground
Ground
-- Ground Input
Ground
Ground Not used Knock sensor
Oil level sensor
Cylinder
4 fuel injector
valve
Cylinder
1 fuel injector valve
Idle speed control valve
Idle speed control valve
Shield, crankshaft sensor
5
6
7
12 Not used
Ground
Intake air temperature sensor
Connector
X60004
8
9 10
11
14 1 1 Not used I
Shield, knock sensor
Shield, sensor
I
Shield, sensor 3
Shield, itnock sensor
Input
- Knoclc sensor
Knock sensor
Knock sensor
Knock sensor
Instrument cluster
Output
2 llnput l~erminal 30 voltage supply /Megrated instrument cluster control module (IKE)
Alt. charge indicator signal, terminal 61 1
Not used
Start signal terminal
50
Not used
15
16
17
18
Output
Ignition switch
Not used
Not used
Activation of relay for fuel pump
Not used
19
Fuel pump relay
Output Not used
I I I 20 loutput ICARB signal /Data link connector
Not
used
Not used
Engine speed signal output (TD)
Not used
Light module
21
Cruise control module (Tempomat)
22 llnput I Right rear wheel speed signal /ABS/ASC or ABSIDSC control module
Oulput
Washer
fluid level,
brake fluid level

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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

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130-74
I Fuel Injection
Evaporative system pressure leak
diagnosis, overview
The M62 TU engine is equipped wlth an evaporative fuel sys-
tem pressure leak diagnosis system. The main component of
this system is the leakdiagnosis pump (LDP). The function of
the LDP is to pressurize the fuel tank and the evaporative
emission system for the purpose of detecting leaks.
This system iscapable of detecting a
lealcas small as0.5 mm.
The LDP, located in the left rear wheel housing, contains the
following:
Vacuum chamber. Pneumatic pump chamber
DME activated vacuum solenoid
Reed switch (provides switched voltage
feedback signal to
DME).
The vacuum supply line is in the wiring harness from the en-
gine compartment and runs down the driver's side of the vehi-
cle.
The canister vent valve is
~ntegrated into the LDP, which IS
electrically controlled by the ECM. The canister vent valve is
opened to provide fresh air entry into the fuel system only dur-
ing purge operation.
- Purge operation characteristics:
Off idle through full throttle: purge valve opened by pulse
width modulated (PWM) control of the ECM. PWM duty cy-
cle varies by engine operating conditions
(e.g. warm idle,
purge valve opened slightly; cold
idleldecel with engine
temp
< 67" C. purge valve always closed).