electronic diagram BMW 525i 2001 E39 Workshop Manual

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Lnition switch
4 The positive (+) power supply to the ignition coils comes to
the ignition switch via an unloader relay. When the ignition
switch is turned on, the relay closes, to provide voltage to the
ignition coils. The coils are then actuated at the negative side
by the engine control module.
NOTE-
Schematic diagrams shown are for illustrative purposes only.
See ELE Electrical Wiring Diagrams for engine manage-
ment specific wiring information.
WARNING- Do not touch or disconnect any cables from the coils while
the engine is running or being cranked by the starter:
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.
* Connect and disconnect the DME system wiring and
test equipment leads only when the ignition is
OFF
Before operating the starter without starting the engine
(for example when
making a compression test), always
disable the ignition.
4 Knock sensors (arrows) monitor the combustion chamber for
engine-damaging knock. Six-cylinder models (shown) use
two sensors with each sensor monitoring three cylinders.
V-
8 models use four sensors, each monitoring two cylinders. If
engine
knock is detected, the ignition point is retarded by the
ECM.
I Ignition advance Ignition timing is electronically mapped and not adjustable.
The ECM uses engine load, engine speed, coolant tempera-
ture, knock detection, and intake air temperature as the basic
inputs for timing control.
A three dimensional map similar to
the one shown is digitally stored in the ECM.
- The initial ignition point is determined by the crankshaft
speed sensor during cranking. Once the engine is running.
timing is continually adjusted based on operating conditions.

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Fuel Injection 1
Working in right rear of engine compartment:
Release interior ventilation filter cover latch
(A) and re-
move cover.
Release plastic locking tab
(6).
Rotate duct inward (arrow) to unlock from bulk head and
remove duct.
Release spring
lock (C) to remove lower iilter housing.
Slide filter housing away from inner fender to remove.
- Remove electrical box (E-box) cover fasteners and remove
cover.
NOTE-
OBD I1 fault memory (including an illuminated MIL) can
only be reset using an electronic scan tool. Removing the
connector from the ECM or disconnecting the battery will
not erase the fault
memory.
The BMW-dedicated 20-pin diagnostic linlc connector
(DLC) is in the right rear of the engine compartment.
The 16-pin OBD
I1 diagnostic connector (arrow) is located
inside the car on the lower left dash panel.
ECM relay, testing
Fuses lor ECM In E-bbx 502130488
4 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.
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.

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- -.
Fuel Injection
SIEMENS MIS 42.0 AND 43.0
When system faults are detected, a diagnostic trouble code
(DTC) is stored in the engine control module (ECM). The MIL
also illuminates
if an emissions-related fault is detected.
When faults arise, or
if the malfunction indicator lamp (MIL) is
illuminated, begin troubleshooting by connecting BMW ser-
vice tester
DISplus, MoDiC, GTI or equivalent scan tool. The
capabilities of OBD
II software has the potential to save hours
of diagnostic time and to help avoid incorrect component re-
placement and possible damage to system components.
CAUTION-
* The tests in this section may set fault codes (DTCs) in tlie
ECM and illuminate the MIL. After all testing is completed,
access and clear DTC fault
memory using an OBD I/ or
BMW compatible scan tool. See
OBD On-Board Diag-
nostics.
Only use a
dgital multimeter for electrical tests.
Relay positions can vary. Be sure to confirm
relayposi-
tion by identifying the wiring in the socket using the wir-
ing diagrams found in
ELE Electrical Wiring
Diagrams.
NOTE-
- OBD I1 fault memory. (including an illuminated MIL! can
only be reset using the special scan tool. Removing the
connector from the ECM or disconnecting the battery will
not erase the fault memory.
The BMW-dedicated 20-pin diagnostic
linlc connector
(DLC) is in the right rear of the engine compartment The
20-pin DLC is discontinued on models after
6/2000.
The 1 &pin OBD I1 diagnostic connector (arrow) is located
inside the car on the lower left dash panel.
The MS
42.0 and MS 43.0 systems manage the following
functions.
- Air:
Idle speed valve
Electronic throttle
Hot film mass air flow (MAF) sensor
Resonance-turbulence intake control
- Fuel:
* Fuel supply
Running losseslnon return
Fuel injection

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130-50
Fuel Injection
Bosch M5.2
ECM relay
1 HoL al ail iirnel XOL a1 ail limes
i--[-----i F109 (BOA) electronics I L.$.....: .I:
ECM relay . . . . . . . . . ,
8,s
:,
6 1 .. ... ~~.~~. . ...... .-, Engine control ii~~-~.~~..~ ........ ~~~~~~.~~~~:. module relay -;I
Of?
,c,;,,,
< With ignition off, remove ECM relay (arrow) in electronics
box (E-box) at right rear of engine compartment.
NOTE-
Relay locations can vary. Conh relay identification by
matcliing wiring colors and terminal numbers.
4 Check for voltage at terminal 6 of main relay socket (30-red
wire). On M5.2 cars also check for battery voltage at terminal
8.
. . . . . . . . . ,
If battery voltage is present, continue testing
.
If battery voltage is not present, check large red wire(s) in
relay socltet. See
ELE Electrical Wiring Diagrams.
%P,,tt
- Reinstall relay and turn ignition on. Gain access to underside
of relay socket and
checlc for ground at terminal 4 (85-brown
wire).
. . . . . . . . . . . . - - - - - - - - - . - - - . . l ,,-. ; Engine i f .: , ; Fuse carrier .,A . :engine /;is? /control L.!.!! .... 1.: ...... !.::..! I lij :module electronics If
ground is present, continue testing
If ground is not present, signal from ECM is missing. Checic
wire between ECM and relay.
4 With ignition on and relay installed, check for battery voltage
at terminal
2 (87-redlwhite wire). On M5.2.1 cars also checlc
for battery voltage at terminal 5.
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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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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130-70
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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300 Suspension. Steering and Brakes .
Genera8
General ........................... .30 0.2
Aluminum suspension components
...... .30 0.2
Front Suspension ................. .30 0.2
Front suspension 6-cylinder models
(525i.5281. 530i) ..................... .30 0.3
Front suspension V-8 models (540i) ...... .30 0.4
Rear Suspension .................. .30 0.5
Sedan models
....................... .30 0.5
Rear suspension sedan models ........ .30 0.6
Sport Wagon models ................. .30 0.6
Rear suspension Sport Wagon
(with coil springs)
.................... .30 0.7
Rear suspension Sport Wagon
(EHC with air springs)
................. .30 0.8
EHC operational diagram .............. .30 0.9
Steering ......................... .30 0.10
Rack-and-pinion steering ............. .30 0.10
Recirculating ball and nut steering ...... .30 0.10
..................... Brake System 300-10
Wheels and Tires ................. 300-1 1
............... Rim and tire sizes table 300-1 1
Electronic Brake and Stability
.................. Control Systems 300-1 1
E39 electronic brake and stability
........ control systems application table 300-12
........................ ABS system 300-1 2
Automatic Stability Control (ASC)
....... 300-12
ABSIASC traction control system ....... 300-13
Dynamic Stability Control (DSC)
........ 300-14
Ride Height ....................... 300-14
......... Front ride height specifications 300-1 5
......... Rear ride height specifications 300-16

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51 5-2
/Central Locking and Anti-Theft
This section covers repair information for door, trunk and car-
go compartment locks, central locking, electronic
immob~liza-
tion (EWS) and anti-theft alarm (DWA).
€39 cars are equipped with sophisticated self-diagnostic elec-
trical systems. When experiencing malfunctions relating to
central locking. EWS or anti-theft systems, start the diagnosis
process using the
BMW service tester DIS, GT 1, MoDiC or
equivalent scan tool. An advanced diagnostic scan tool can
usually pinpoint electrical faults quickly and safely.
Additional electrical information can be found in:
610 Electrical Component Locations
ELE Electrical Wiring Diagrams
Central locking in E39 vehicles controls the door
locks, trunk
or tailgate lock and fuel filler flap lock. The control module for
the Central Body Electronics system (ZKE
Ill), lknown as the
General Module (GM
Ill), controls central locking.
ZKE
Ill manages the following central locking related func-
tions:
Central locking
* Keyless entry
Key memory
Power trunk release
Electric opening of tailgate
DWA alarm system
Diagnosis
General Module
4 The General Module (GM) (arrow) is responsible for the op-
eration of central body electronics. The GM is located behind
the glove compartment.
Based on input information, the GM uses internal transistors
to switch current flow (providing voltage or ground) through
circuits and actuators. Actuators are the final controlling de-
vices used by GM to operate or control various output func-
tions such as relays and motors.
The accompanying schematic, Central locking inputs and
outputs, illustrates the GM central locking system.

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721 Airbag System (SRS)
........................... General ............................ 721-2 Airbags 721-8
..... E39Airbags ......................... 721-3 Driver airbag. removing and installing 721-8
Two-stage airbag (MRS 111) ............ .72 1.4 Passenger airbag. removing and installing . 721-9
Airbag indicator light .................. .72 1.4 Door mounted side-impact airbag.
............... Warninas .......................... .72 1.5 removina and installina 721-10 .
..... Head protection airbag components 721
-1 1 Airbag Electronics ................. '721-6 Head protection airbag (HpS) .......... 721-12 MRS ............................... 721-6
MRS
airbag system diagram ........... .72 1.6
MRS control module. replacing ......... .72 1.7
Side-impact crash sensor.
removing and installing
................ .72 1.7

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721-6
I Airbag System (SRS)
MRS
The MRS control module contains the electronic crash sensor
for frontal impact. Sensors mounted on the driver and
pas-
sengerfloor are used for side impacts. The MRS control mod-
ule
is located between the front seat under the center
console.
MRS airbag system
diagram
1. Driver's side airbag
2. Passenger's side airbag
3. Right side impact sensor
4. Seat occupancy sensor pad
5. Right side impact airbag
6. SBE control module (analog to
digital converter)
7. Passenger pyrotechnic seat belt
tensioner and seat belt
mi-
croswitch (Hall sensor MRS Ill)
8. MRS control module
9. Driver pyrotechnic seat belt ten-
sioner and seat belt microswitch
(Hall sensor MRS
Ill)
10. Left side impact airbag
11. Left side impact sensor