2001 BMW 525i Start

Downloaded from www.Manualslib.com manuals search engine
- 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.

Downloaded from www.Manualslib.com manuals search engine
130-51
Fuel Injection
Oxygen sensors, checking
The oxygen sensor provides an input voltage signal [0.2 vdc
(lean) to 0.8 vdc (rich)] to the
ECM based on the oxygen con-
tent in the exhaust gas. To generate voltage, the sensor tem-
perature must exceed 575"
F (300" C). Therefore the sensor
is electrically heated.
NO JE -
The test given below is not a conclusive test of oxygen sen-
sor efficiency and does not test how the oxygen sensor re-
acts to changing conditions. Pin numbers and wire colors
can vary Always check the wiring diagrams to confirm wire
color and pin assignment.
0 The oxygen sensorconnectorplugs are locatednext to the
catalytic converters.
With connector attached to sensor, connect digital voltmeter
between
A and B wires in connector.
WARNING -
Exhaust manifolds andpipes can be hot enough to cause se-
rious burns. Wear suitable heavy gloves and other appropri-
ate protection.
NOJE-
Connector style may vary depending on system application.
Consult wiring diagram for system-specific wiring. See
ELE
Electrical Wiring Diagrams.
Start engine.
A fluctuating voltage signal should show on the
meter.
If voltage is incorrect, turn engine off and check pre-
heater circuit as described below.
NOJE-
To check sensor response to lean and rich mixtures, create
an air leak.
Oxygen sensor
voltage at idle
- Connect digital voltmeterbetween sensor heaterwires (white
wires,
C and D). Start engine and check for battery voltage.
If voltage is not present, check oxygen sensor heater fuses.
0.2 to 0.8 vdc fluctuating
NOJE-
The oxygen sensor heater is powered via fusedpositive (+)
battery voltage and a switchedground from the ECM. See
ELE Electrical Wiring Diagrams for specific circuit informa-
tion.
- The ground side of the oxygen sensor heater circuit is pulsed
on and off by the
DME control module.

Downloaded from www.Manualslib.com manuals search engine
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

Downloaded from www.Manualslib.com manuals search engine
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)

Downloaded from www.Manualslib.com manuals search engine
Fuel lnjection
Table e. Bosch 5.2.1 ECM pin assignments
Pin
Isignal 1 Description 1 Note
Connector
X60003
1
2
3
4
5
6
7 8
9 10
11
12
13
14
15
16
17
18
19
20
21
ate alr empe
Output
Output
Output
Ground
Ground
Output
Output Input
Input
Input
Ground
22
23
24
25
26
27
28
29
30
Injection signal
Injection signal
Signal, evaporative emission valve
Not used
Not used
Ground for electronic components
Not used
Not used
Hot film mass air flow sensor ground
Throttle position sensor voltage supply
Signal, engine coolant temperature sensor
Hot
film mass air flow sensor signal
Throttle position sensor slider voltage
Shield, throttle potentiometer (DK) Not used
Injection signal
Injection signal
Not used
Not used
Input
Input
Input
Ground
Output
Output Evaporative emission
valve
Ground point right-hand drive
Ground connector
X6460
Hot film mass air flow sensor
Throttle position sensor
Signal, secondary air injection pump valve
Terminal
30 voltage supply
Alternator
D+ (terminal 61) signal
injection signal
Injection
signal
Not used
Not used
Not used
Not used
Camshaft position sensor signal
Ground Dual temperature switch
Hot film mass air flow sensor
Throttle position sensor
Throttle position sensor
Cylinder
8 fuel injection valve
Cylinder
5 fuel injection valve
Secondary air injection pump
valve
Starter
Alternator (generator)
Cylinder
7 fuel injection valve
Cylinder 6 fuel injection valve
Camshaft position sensor (Hall effect) Dual temperature
switch

Downloaded from www.Manualslib.com manuals search engine
-
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

Downloaded from www.Manualslib.com manuals search engine
Fuel Injection
Table Pin
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
1
2
3
4
5
6
7
8
9
e. Bosch 5.2.1
Signal
Input
Input
Ground
Output Input- output
Output
Input- output
Input- output
Output
Connector
X60005
Output
Output
Output
Output
Ground
Output
Output
Output
Output
ECM pin assignments
Description
Not used
Not used
Voltage supply, terminal
15
Not used
Not used
Compressor ON signal from engine control module
(DME)
Ground
Not used
Diagnosis signal TXD
Communication
link (EWS)
Signal, leak diagnosis pump
Not used
CAN-Bus high
CAN-Bus low Not used
Not used
Start
signal
Terminal 1 signal
Terminal
1 signal
Terminal
1 signal
Terminal
1 signal
Ground
Terminal
1 signal
Terminal
1 signal
Terminal
1 signal
Terminal 1 signal Note
Fuse
F14
Heating
and AIC control module
Lealtage diagnosis pump
Data
iinit connector
Electronic immobilizer (EWS)
Leakage diagnosis pump (LDP)
CAN link
CAN link
Starter relay
Cylinder
7 ignition coil
Cylinder 8 ignition coil
Cylinder
2 ignition coil
Cylinder
3 ignition coil
Ground point
Cylinder
1 ignition coil
Cylinder
4 ignition coil
Cylinder 5 ignition coil
Cylinder
6 ignition coil

Downloaded from www.Manualslib.com manuals search engine
130-67
Fuel Injection /
ME 7.2 system overview
The Bosch ME 7.2 system is used on 1999 - 2002 540i mod-
els.
1 4 The ME 7.2 enaine control module (ECM). located on the
l and a combined total of 134 pins.
--__-- 1 I. 9 pin connector
12 3 4 5 2 24 pin connector
0lliC;nii, 3. 52 pin connector
4. 40 pin connector
5. 9 pin connector
The ME 7.2 system has the following functions or capabilities:
Electronic throttle control (EDK) integrates idle and cruise
control functions. ECM carries out all throttle and idle con-
trol functions directly via EDK system.
Leak diagnosis pump
(LDP) control and feedback monitor-
ing for evaporative system leak testing.
Batterylalternator charge logic (idle speed varies with bat-
tery state of charge).
CAN-Bus communications with instrument cluster.
EWS
111 (3.3) "rolling code" ISN interface.
Ignition
knock sensors.
DSC (dynamic stability control) torque reduction.
Monitoring and control of VANOS
(camshaft timing) with
active Hail sensor for camshaft position monitoring.
Integrated altitude sensor.
One touch engine start control
Single speed secondary air injection system.
Long life spark plugs.
IHKA auxiliary (electric) cooling fan control.
All emissions-related ME 7.2 electrical components are mon-
itored for faults. if driveability complaints are encountered or
the malfunction indicator
light (MIL) is illuminated, interrogate
fault memory using a compatible scan tool.
4 Use a break-out box for ME 7.2 system testing and diagnosis
at the control module
(break out box set: BMW special tool
90
88 6 121 300).
Electrically heated (characteristic
map) cooling system
DME Harness Connector thermostat.