2001 BMW 525i Valve

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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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130-54
I Fuel Injection ldle speed control valve,
testing and replacing
ldle speed is maintained by the ECM through the idle speed
control valve. The idle control function compensates for en-
gine load and engine operating conditions. ldle speed is
adaptive through the ECM and no adjustments can be made.
Before checking valve, confirm that throttle position sensor is
working correctly.
NOTE-
The test given below is an electrical check only. It does not
check the mechanical operation of the valve. If the valve is
sticking, hanging up or is sluggish in operation, substituting a
Inown good valve is the best way to check it.
With engine running, check that idle speed control valve is
buzzing.
Turn on
AIC or shift car into drive. ldle should remain steady
or increase slightly.
If valve is not buzzing, or if idle decreases in step above, stop
engine and disconnect harness connector from valve.
4 Check resistance of valve across its terminals. Test values
are listed below.
ldle speed control valve coil resistance
Terminals
1 and 2 20 +2%
Terminals 2 and 3 20 +2Q
Terminals 1 and 3 40 +4%
NOTE-
If you suspect an intermittent fault, lightly tap the valve while
testing resistance.
With valve harness connector disconnected, check for bat-
tery voltage at redlwhite wire in connector with ignition on.
If . ~~ ~~
there is no voltage, check wiring between connector and 7 ECM relay. See ELE Electrical Wiring Diagrams.
NOTE- - The idle speed control valve receivespositive (+) battery volt-
age from the ECM (DME main) relay

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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
Intake air temperature
([AT) sensor,
testing and replacing
Disconnect harness connector from intake air temperature
sensor
(A) at air filter housing.
Turn ignition on. Using a digital voltmeter, check for
5 volts
between supply voltage wire in connector and ground.
If volt-
age is not present, test ECM
inputs/outputs as described lat-
er.
With harness connector disconnected, test resistance across
sensor terminals. If any faults are found, replace IAT sensor.
IAT test resistance
0 lV *lac (50" i-2°F) 7-1 1.6 k.0.
020' kl°C (68' 322°F) 2.1-2.9 it.0.
080" ?lac (176" i-2°F) 0.27-0.40 itn
Auxiliary throttle valve (ADS)
(M62 and M62 TU engine), replacing
ADS components 540i models with ASC and DSC are fitted with a motor-driv-
en auxiliary throttle valve and housing ahead of the standard Throttle position switch throttle housing. The ADS throttle valve controls engine throt-
tle intervention based on signals from the DME control mod-
ule if road conditions, such as slipping driven wheel, warrant
reduced engine power.
ADS throttle housing
Bowden cable NOTE-
Before replacing the ADS throttle housing, read DME fault
ADS lhroltle actualor codes.
- ADS throttle housing replacement:
Switch off ignition and disconnect electrical connector on
ADS throttle body.
Remove hose from idle control valve.
Loosen hose clamps and remove throttle housing air in-
take boot.
Disconnect cable from ADS throttle body.
- Unscrew 3 bolts and remove ADS throttle body.
Installation is reverse of removal.
- Adjust cable so that no free play is present.

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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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130-59
Fuel Injection
:-- -i. Evaporative emissions
1.
control diagram (M5.2.1)
i 1
i I @ 1. ECM r.=.:-:, 2. Purge valve
3. Leak detection pump (LDP)
4. Liquid vapor separator
5. Purge canister
6. Filter
Bosch M5.2 ECM pin assignments
(M62 up to 911997)
Tabled. Bosch M5.2 ECM pin assignments
I' 1- 1. . . -
4 1 output / Cyl. 4 fuel injection valve I Cyl. 4 fuel injection valve (cycled ground)
Pin
1
2
3
i I
I
7 / output I Cyl. 6 fuel injection valve I Cyl. 6 fuel injection valve (cycled ground)
Type
output
output
output
I I ,
8 1 output I Malfunction indicator light (MIL) (USA only) I lliumlnated for exhaust gas related diagnostic trouble code
5
Component/function
Oxygen sensor heater signal
Idle speed control -closing winding
Cvl. 1 fuel iniection valve Note
DME heated oxygen sensor
1 splice
idle speed control valve (cycled ground)
Cvl. 1 fuel iniection valve lcvcled around)
6 1 ground I Fuel injection valve ground 1 Ground
output
9
Not
used
Not used
11
12
13
Cyl. 5 fuel injection valve
10 1 input I Electronic immobilizer (EWS) / Electronic immobilizer (EWS) control unit
input
Heated oxygen sensor signal Cyl.
5 fuel injection
valve (cycled ground)
output
input
input
16
Start signal Starter relay
NC compressor signal
Terminal
50 signal
Knock sensor signal
17 1 ground I Hot film mass air flow (MAF) sensor ground I Hot film mass air flow (MAF) sensor ground
output Heating and
A/C control module
Ignition switch
Knock sensor
Intake air temperature intake air temperature sensor (voltage value)

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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
I 68 1 / Not used
Table
d. Bosch
M5.2 ECM pin assignments
I I I
69 1 input I AIC system standby signal (> 10 V) 1 Heating and AIC control module
Pin
57
58
59
60
61
62
63
64
65 66
67
Type
input
input
input
input
I 70
72
73
74
Componentlfunction
Not used
Not used
Heated thermostat (characteristic map, cooling)
Programming voltage input (voltage
value)
Signal input Evaporative emission valve
Not used
Fuel pump relay (ground)
Not used
Not used
Not used
Not used
75
76
77
78
79
80
Note
Characteristic map, cooling
Data
llnlc connector
Evaporative emission valve
Fuel pump relay
71 1 ground I Control module ground I Ground splice
input
input
81
input input
input
input
output Not used
I
Knock sensor signal
Not used
Not used
Coolant temperature
82 1 I Not used
83
I I
Knock sensor
Dual temperature
swltch
Not used
Heated oxygen sensor signal (voltage
0.1-1.0 V)
Heated oxygen sensor
signal (voltage 0.1-1.0 V)
Crankshaft position sensor signal (speed and
position, AC voltage)
Right rear wheel speed signal
TD signal (engine speed)
85
I I I
Heated oxygen sensor II behind catalytic converter
Heated oxygen sensor
I behind catalytic converter
Cranitshaft positionlrpm sensor
ABSIASC control module
TD signal splice
84 1 / Not used 1
output
88
86
1 input-output 1 CAN-Bus high I Transmission conlrol module (AGS)
input-output
Injection signal
input-output Integrated instrument cluster control
module (IKE)
CAN-Bus low Transmission control module (AGS)
Data
linlc TxD Data link connector