1997 BMW 540i Ignition switch diagram

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YOU are now in Volume I
I
Foreword ................... .. ........................................................................\
.......... v
Index
........................ .. ................................................................ rear of manual
General, 001 General Warnings and Cautions 002 Vehicle Identification and VIN Decoder
Maintenance OiO 020 Maintenance
Engine
100 Engine-General 110 Engine Removal and Installation
113 Cylinder Head Removal and
Installation
116 Cyiinder Head and Valvetrain 117 Camshaft Timing Chain
119 Lubrication System
200 Transmission-General
2 Transmission 210 clutch 230 ManualTransmission
I20 Ignition System
121 Battery, Starter, Alternator
130 Fuel Injection
160 Fuel Tank and Fuel Pump 170 Radiator and Cooling System
180 Exhaust System
240 Automatic Transmission
250 Gearshift Linkage 260 Driveshaft
Suspension, 300 Suspension, Steering and 330 Rear Suspension
Brakes-General 331 Final Drive
Steering and No Front Suspension 340 Brakes
320 Steering and Wheel Alignment
400 Body-General
410 Fenders, Engine Hood 411 Doors
412 Trunk Lid, Tailgate
510 Exterior Trim, Bumpers 512 Door Windows
Equipment 513 Interior Trim
7
Equipment and 720 seat Belts
Accessories 721 Airbag System (SRS)
OBD On-Board Diagnostics
. ............ ..
515 Central Lociting and
Anti-Theft
520 Seats 540 Sunroof
.................................................................... Foreword .............................. .. v
Index ................... .. ................................................................ rear of manual
Electrical
6 system
600 Electrical System-General 620 Instruments
610 Electrical Comoonent Locations 630 Liohts
611 wipers and washers 612 Switches eati in^ and Air Conditioning
Radio
. ........... ........ .........................
Electrical Wiring Diagrams

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. .- -
L
- --
- - -. - -- Lubrication ~~stern
- Remove pressure gauge and reinstall pressure switch with
new sealing washer.
Tightening torque
Oil pressure switch to oil filter housing 27 Nm (20 ft-lb)
If testing shows low oil pressure, one or more of the following
conditions may be indicated:
Worn or faulty oil pump or faulty pump pressure relief valve
Worn or damaged engine bearings
Severe engine wear
Any of these conditions indicate the need for major repairs.
Oil pressure warning system, testing
4 When the ignition is turned on, the oil pressure warning light
comes on. When the engine is started and the oil pressure
rises slightly, the oil pressure switch (arrow) contact opens
and the warning light goes out. Make sure the oil level is cor-
rect before making tests.
- Turn ignition switch on.
- Warning light on instrument panel must light up
- Remove connector from oil pressure switch.
Warning light on instrument panel must go out.
NOTE-
If the light does not go out, the wiring to the switch is most
likely grounded somewhere between the switch terminaland
the warning light See
ELE Electrical Wiring Diagrams for
electrical schematics.
- If warning light does not light when ignition is on, remove con-
nector from oil pressure switch and use a jumper wire to
ground connector terminal to a clean metal surface. The oil
pressure warning light should come on.
NOTE-
If there are two wires to the oil pressure switch, ground the
brown/green wire that carries the signal to the warning light.
- If the warning light comes on, check the switch as described
in the next step. If the warning light does not come on, the
wiring to the instrument cluster or to the light itself is faulty.

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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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I Battery, Starter, Alternator
- Check for battery voltage at terminal 50 of starter motor with
key in start position. If voltage is not present, check wiring be-
tween ignition switch and starter terminal. Check the EWS
system and other inputs that disrupt terminal
56 to the start-
er. See ELE Electrical
Wiring Diagrams. If voltage is
present and no other visible wiring faults can be found, prob-
lem is most likely in starter motor.
Starter, removing and installing
(6-cylinder engine)
The starter is removed from below. Access to starter bolts is
difficult. Be sure to have the proper tools on hand before pro-
ceeding.
NOTE-
Access to the starter wiring is very limited. Forbetteraccess,
it may be necessary to remove the intake manifold.
- Disconnect negative (-) battery cable.
CAUTIOI\C
Prior to disconnecting the battern read the baltery discon-
nection cautions
in OOlGeneral Cautions and Warnings.
Remove complete air filter hous~ng:
Loosen intake duct hose clamp (A) at throttle assembly.
Loosen clamp and remove idle control hose from intake
duct
(B) and disconnect idle speed control valve electrical
harness connector.
Disconnect electrical harness connector
(C) from mass air
flow sensor.
Remove air filter housing mounting screw (D)
Disconnect vent tube
(E).
Loosen air intake duct clamp (F).
Carefully lift air filter housing out of engine bay.
Disconnect throttle cable.
Raise vehicle and support safely.
WARNING-
Make sure the car is stable and well supported at all times.
Use a professional automotive
lift orjack stands designed for
the purpose. A
floorjaclc is not adequate support
- Working underneath car, remove engine splash shield
- Disconnect fuel lines and harness connectors from retaining
brackets, as necessary.

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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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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

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Gaskets and seals 01
0-9
Gearshift automatic transmission
adjusting
250-7
shift interiock. checkino function " 250-9
shiftloclc. checicino function 250-8 - manual transmission
gearshift lever, removingiinstalling
250-5
steptronic 250-7
General module (GM Ill)
600-8
see also Central locking
Generator see Battery, starter, alternator
Glass see Door window
Glove compartment
513-16
see also
Global positioning system
(GPS)
620-9
Grill
see Exterior trim
Grounds
100-5
Guide link
see Rear suspension, suspension
arms
Halogen headlight
630-5
Hand brake
see Brakes, pariring brake
Handle, door
see Door
locks
Hatch seeTailgate
Hazard warning switch
see Switches Headlight
housing trim
see Exterior trim
washer611-17 see also Lights
Headlight spray
nozzle
611-17
Headlight switch
see Switches
Heater core
see Heating
Heater valve
see Heating
Heating lieater core, replacing
640-18
lheater core temperature sensor,
removingiinstalling
640-12 heater valve, replacing 640-17
IHKA housing, removinglinstallin~
640-21
see also NC
Hood
410-6
Hood latch and release
410-10
Hydraulic valve lifters
see Cylinder head and valvetrain
IAT
(lntalce air temperature) sensor
see 130
under appropriate fuel
injection system
idle speed control valve
see 130
under appropriate fuel injection system
Idle stabilizer
see 130
under appropriate fuel
injection system, idie speed controi
valve
idler arm
320-30
lgnition coll
see lgnition system
lgnition interlock
320-13
lgnition lock cylinder
removingiinstalling
320-1 1. 612-4
lgnition switch
seeSwifches
Ignition system
diagnosis checking for
spark 120-10
disabling ignition system 120-10 misfire detection 120-6
oscilioscope diagrams 120.6
troubleshooting 120-6
camshaft position sensors 120-14 coils 120.10
crankshaft speed sensor 120-12 firing order 120-9
knoclc sensors 120-16
IHKA
see NC
IHKR see NC
Injector
see 130 under appropriate
fuel
injection system, luel injector
Input shaft
oil seal
see Manual transmission, oil seals
Inspection
see Maintenance
Instruments GPS see Global positioning system
(GPSI layout 6202
removingiinstalling 620-8 self-testing 620-6
Intake air temperature sensor (IAT)
see 130 under appropriate fuel
injection system
Intake manifold
removingiinstalling
6-cvlinder enoine 110-10. 113-8. 113-22 -
V-8 engine (M62) 113-56
Integral link
see Rear suspension, suspension
arms
lnterior lights
see Lights
lnterior protection
(FISIUIS) 515-25
lnterior trim
513-13
lnterior ventilation microfilter see
NC, ventilation microfiller