1995 BMW M3 ignition system

600-
4



ELECTRICAL
SYSTEM-GENERAL

Voltage
and
Voltage
Drops

The
wires,
connectors,
and
switches
that
carry
current
are

designed
with
very
low
resistance
so
that
current
flows
with
a

minimum
loss
of
voltage
.
A
voltage
drop
is
caused
by
higher
than
normal
resistance
in
a
circuit
.
This
additional
resistance

actually
decreases
or
stops
the
flow
of
current
.
A
voltage
drop

can
be
noticed
byproblems
ranging
fromdim
headlights
to
sluggish
wipers
.
Some
common
sources
of
voltage
drops
are
corroded
or
dirty
switches,
dirty
or
corroded
connections
or

contacts,
and
loose
or
corroded
ground
wires
and
ground
con-

nections
.

A
voltage
drop
test
is
a
good
test
to
make
if
current
is
flowing
through
the
circuit,
butthe
circuit
is
not
operating
correctly
.
A
voltage
drop
test
will
help
to
pinpoint
a
corroded
ground
strap
or
a
faulty
switch
.
Normally,
there
should
be
less
than
1
volt

drop
across
most
wires
or
closed
switches
.
A
voltage
drop
across
a
connector
or
short
cable
shouldnot
exceed
0
.5
volts
.

Voltage,
measuring

1
.
Connect
digital
multimeternegative
lead
to
a
reliable
ground
point
oncar
.

NOTE-

The
negative
(-)
battery
terminal
is
alwaysa
good
ground
point
.

2
.
Connect
digital
multimeter
positive
lead
to
point
incir-
cuit
you
wish
to
measure
.
See
Fig
.
1
.
If
a
reading
is
ob-
tained,
current
is
flowing
through
circuit
.

NOTE-

The
voltage
reading
shouldnot
deviate
more
than
1
volt
from
the
voltage
at
the
battery
.
If
the
voltage
drop
is
more
than
this,
check
for
acorroded
connector
or
cose
ground
wire
.

ELECTRICAL
TROLIBLESHOOTING

from
Battery

Fig
.
1
.



Digital
multimeterbeing
used
to
test
voltage
.

No
voltage
r_l

-1
Load

LJ

Switch

NOTE-

The
maximum
voltage
drop
in
an
automotive
circuit,
as
recommended
by
the
Society
of
AutomotiveEngineers
(SAE),
is
as
follows
:
0
voltsfor
small
vire
connections
;
0
.1
Volts
for
high
current
connections
;
0
.2
volts
for
high
current
cables
;
and
0
.3volts
for
switch
or
solenoidcon-
tacts
.
On
longer
wires
or
cables,
the
drop
may
be
slight-ly
higher
.
In
any
case,
a
voltage
drop
of
more
than
1.0volt
usually
indicates
a
problem
.

0013238

NOTE-

"
A
voltage
drop
test
is
generally
more
accuratethan
a



Voltage
drop,
testing

simple
resistance
check
because
the
resistances
in-
volvedare
often
too
small
to
measure
with
most
ohm-



Voltage
drop
can
only
be
checked
when
current
is
running
meters
.
For
example,
a
resistance
as
small
as0
.02



through
the
circuit,
suchasby
operating
the
starter
motor
or
ohms
would
results
in
a
3
volt
drop
in
a
typical
150



turning
onthe
headlights
.
A
digital
multimeter
should
beused
amp
starter
circuit
.
(150
amps
x
0
.02
ohms
=3
volts)
.



lo
ensure
accurate
readings
.

"
Keep
in
mind
that
voltage
with
the
key
on
and
voltage
with
the
engine
running
arenotthe
same
.
With
the
ig-



1
.
Connect
digital
multimeter
positive
lead
to
positive
(+)
nition
on
and
the
engine
off
(battery
voltage),
voltage



battery
terminalor
a
positive
power
supply
close
lo
bat
should
be
approximately
12
.6volts
.
With
the
engine



tery
source
.
running
(charging
voltage),
voltage
should
be
approx-
imately
14
.0
volts
.
Measure
voltage
at
the
battery
with



2
.
Connect
digital
multimeter
negativelead
to
other
end
of
the
ignition
on
and
then
with
the
engine
running
to
get



cable
orswitch
being
tested
.
See
Fig
.
2
.
exact
measurements
.

3
.
With
power
on
and
circuit
working,
meter
shows
volt-
age
drop
(difference
between
two
points)
.
This
value
should
not
exceed
1
volt
.

Continuity,
checking
Short
Circuits

from
Battery

CAUTION-

Use
only
a
high
quality
digital
ohmmeter
having
high
input
impedance
when
checking
electronic
componente
.
The
internal
power
source
used
in
most
analog
(swing-need1e)
meterscan
damage
solidstate
components
.

0013239

Fig
.
2
.



Digital
multimeter
being
used
to
check
for
voltage
drop
across
a
switch
.

The
continuity
test
can
beused
to
check
a
circuit
or
switch
.
Because
most
automotive
circuits
are
designed
to
have
little

or
no
resistance,
a
circuit
or
part
of
a
circuit
canbe
easily

checked
for
faults
using
an
ohmmeter
.
An
open
circuit
or
a
cir-

cuit
withhigh
resistance
will
not
allow
current
to
flow
.
A
círcuit
with
little
or
no
resistanceallows
current
to
flow
easily
.

When
checking
continuity,
the
ignition
should
be
off
.
On
cir-
cuits
that
are
powered
at
all
times,
the
battery
should
be
dis-
connected
.
Using
the
appropriate
wiring
diagram,
a
circuit
can
be
easily
tested
for
faulty
connections,
wires,
switches,
relays,
and
engine
sensorsby
checking
forcontinuity
.
For
a
continu-
ity
check
on
a
brake
light
switch,
see
Fig
.
3
..

A
short
circuit
is
exactly
what
the
narre
implies
.
The
circuit
takes
a
shorter
paththan
it
was
designed
to
take
.
The
most

common
short
that
causes
problems
is
a
short
to
ground

where
the
insulation
on
a
positive
(+)
wire
wears
away
and
the

metal
wire
is
exposed
.
When
the
wire
rubs
against
a
metal

partof
thecar
or
other
ground
source,
the
circuit
is
shorted
to
ground
.
If
the
exposed
wire
is
live
(positive
battery
voltage),
a

Puse
will
blow
and
the
circuit
may
possibly
be
damaged
.

ELECTRICAL
SYSTEM
-
GENERAL
600-
5

Brake
light
switch

Brake
pedal
in
rest
position

Q

Brake
pedal
depressed
Brake
light
switch

Fig
.
3
.



Brake
light
switchbeing
tested
for
continuity
.
With
brake
ped-
alin
rest
position
(switch
open)
there
is
no
continuity
(infinite
ohms)
.
With
pedal
depressed
(switch
closed)
there
is
continu-
ity
(zero
ohms)
.

Shorts
to
groundcanbe
located
with
a
digital
multimeter
.
Short
circuits
are
often
difficult
to
locate
and
may
vary
in
na-
ture
.
Short
circuits
can
befound
using
a
logical
approach
based
onthe
current
path
.

CAUTION
-

"
On
circuits
protected
with
high
rating
fuses
(25
amp
and
greater),
the
wires
or
circuit
compo-
nents
may
be
damaged
before
the
fuse
blows
.
Always
check
for
damage
before
replacing
fuses
of
this
rating
.

"
When
replacing
blown
fuses,
use
only
fuses
hav-
ingthe
correct
rating
.
Always
confirm
the
correct
fuse
rating
printed
on
the
fuselrelay
panelcover

DC

ELECTRICAL
TROUBLESHOOTING

610
Electrical
Component
Locations

GENERAL
...........
.
.
.
.
.
.
.
.
.
........
610-1



FOSE
POSITION
TABLES
..
.
.
.
.
.
.....
.
610-19

FUSE
AND
RELAY
POSITIONS
.
...
.
.
.
.
.
610-1

Fuse
Positions
.
.
.
................
.
.
.
.
.
610-1

Relay
Positions
.
.
.
.....
.
.
.
........
.
.
.
.
.
610-2

Auxiliary
RelayPanel
.....
.
...
.
........
.
610-2

SplicePanel,
Left
.
.
.
...
.
.
.
...
.
........
.
610-2

SplicePanel,
Right
.
.
.
.
.
.
.
.
...
.
.........
610-3

COMPONENT
LOCATIONS
.
.
.
.
.......
.
.610-3

Component
Location
Table
.
.
.
.
.
.
.........
610-9

GENERAL



FUSE
AND
RELAY
POSITIONS

This
repair
group
covers
f
use,
relay,
and
control
module
lo-



The
front
power
distribution
box,
an
auxiliary
relay
panel,cation
information
.
Electrical
equipment
and
accessories
in-



and
two
auxiliary
splice
panels
contain
most
of
the
fuses
and
stalled
varies
depending
on
model
and
model
year
.
Always



relays
in
E36
vehicles
.
Refer
to
the
component
location
later

confirm
that
the
proper
electrical
component
has
been
identi-



in
this
section,
as
well
as
the
tables
at
the
end
of
this
repair

fied
by
using
the
electrical
wiring
diagrams
.



group
for
electrical
component
location
.

WARNING
-

On
cars
equipped
with
airbags,
special
precautionsapply
to
any
electrical
system
testing
orrepair
.
Air-
bag
units
areexplosive
devices
and
mustbe
han-
dled
with
extremecare
.
Before
starting
any
work
onan
airbag
equipped
car,
refer
to
the
wamings
and
cautions
in
721
Airbag
System
(SRS)
.

CAUTION
-

"
Prior
to
disconnectiog
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.

"
Relay
and
fuse
positions
are
subject
to
changeand
may
varyfrom
car
to
car
.
If
questions
arise,
an
authorized
BMW
dealer
is
the
best
source
for
the
most
accurate
and
up-to-date
information
.

"
A
good
way
to
verify
a
relay
position
isto
com-
pare
the
wiring
colors
at
the
relay
socket
to
thecolors
indicated
on
the
wiring
diagrams
located
at
the
rear
of
this
manual
.

"
Always
switchthe
ignition
off
and
disconnect
the
negative
(-)
battery
cable
before
removing
any
electrical
components
.

"
Connect
and
disconnect
ignition
system
wires,
multiple
connectors,
and
ignition
test
equipment
leads
only
while
the
ignition
is
switched
off
.

"
Only
usea
digital
multimeter
for
electrical
tests
.

ELECTRICAL
COMPONENT
LOCATIONS



610-1

TABLES
a
.
E36Component
Locations
...........
.
.
..
...
610-10b
.
1992
E36
Fuse
Positions
..........
..
.
.
.....
610-20c
.
1993
E36
Fuse
Positions
..........
..
..
.
....
610-22d
.
1994
E36
Fuse
Positions



.........
...
.......
610-24e
.
1995
E36
Fuse
Positions
.........
...
.......
610-26
f
.



1996
E36
Fuse
Positions



.........
...
.......
610-28g
.
1997-1998
E36
Fuse
Positions
..
.
..
...
.......
610-30

Fuse
Positions

CAUTION
-

"
Replace
fuses
with
those
of
the
same
rating
.
In-
stalling
a
fuse
with
higher
rating
can
lead
to
cir-
cuit
failure
and
may
also
start
a
fire
.

"
Relay/fuse
positions
vary
by
model
and
equip-
ment
.

Fuses
number
1
through
46
are
mounted
in
the
front
power

distribution
box
.
See
Fig
.
1.

Fuses
31-46

~
Illlllllllll

°
-
Ilmmlmomlmoi

Fuses
1-20

(a
1
:1
E
El

~
~O!7

L~~n

4~
i
Fuses
21-30

Fig
.1.



Fuse
positions
1-46
in
front
power
distribution
box
.

0013034

FUSE
AND
RELAY
POSITIONS

Tablea
.
E36
Component
Locations

Component



Model
Year



Location



Refer
to
Engine
Compartment
Light
Switch



1993-1996



Over
right
headlight
assembly



Fig
.
7
.

Engine
Control
Module
(ECM)



1992-1998



Right
rear
enginecompartment,
behind
bulkhead
panel



Fig
.
7
.

Engine
Control
Module
(System)



1992-1998



I
Power
distribution
box



Fig
.
2
.
Relay
Engine
Coolant
Leve¡
Sensor



1
1992-1998



1
Left
front
of
enginecompartment,
radiator
coolant
reservoir

Engine
Coolant
Temperature



1992-1998



I
Left
front
of
engine
under
intake
manifold



I



Fig
.
19
.
Sensor



Fig
.
20
.

Evaporative
Emission
Valve



1992-1998



Left
side
strut
Power
area

Evaporator
Temperature
Sensor



1992-1998



Left
side
of
heater
box

EWS
II
Control
Module



1/1995
-
1998



Behind
glove
compartment



Fig
.
8
.
Fig
.
9
.

EWS
II
Ring
Antenna



1
1/1995
-
1998
1
At
ignition
cylinder

EWS
II
Transmitter
Module



1/1995
-
1998



Right
side
of
steering
column
in
auxiliaryrelay
panel



Fig
.
3
.

Exhaust
Gas
Flap
Valve



1996-1998



Left
rear
muffler
area

Flasher
Relay



1992-1998



Power
distribution
box



Fig
.
2
.

Foglight
Relay



1



1992-1998



1
Power
distribution
box



1



Fig
.
2
.

Fresh
Air
FlapActuator



1



1992



1
Right
side
of
heater
box

Fresh
Air
FlapActuator



1
1993-1995



1
Below
right
side
heater
box

Fresh
Air
FlapActuator



1
1996-1998



Below
left
side
heater
box

Fuel
Injectors



1992
-
1998



Top
left
side
of
engine

Fuel
Leve¡
Sensor,
Left



1
1992-1998



/
Under
left
side
of
rear
seat
infuel
tank

Fuel
Leve¡
Sensor,
Right



1



1992-1998



1
Under
right
side
of
rear
seat
in
fuel
tank



1



Fig
.
28
.

Fuel
Pump



1



1992-1998



1



Under
right
side
of
rear
seat
in
fuel
tank



1



Fig
.
28
.

Fuel
Pump
Relay



1



1992-1998



1
Power
distribution
box



1



Fig
.
2
.

Fuel
Pump/Start
Identification
Relay



1994
-
1996



Power
distribution
box

Fuel
Tank
Pressure
Sensor



1
1997-1998



1
Right
rear
wheel
well
behind
trim
liner

ELECTRICAL
COMPONENT
LOCATIONS



610-13

Fuse
andRelay



x(Power



11992-1998



I
Left
side
of
engine
compartment



I



Fig
.
2
.
Distribution
Box



Fig
.
7
Fig
.
10
.

Gas
Filler
LockMotor



1992-1998



Right
side
of
luggage
compartment

Gear
Position/Neutral
Safety
Switch



1992-1998



Next
to
gear
shift
lever
in
center
console



Fig
.
29
.
(Automatic
Transmission
Range
Switch)

Glove
Compartment
Lock
Motor



1994-1998



Behind
glove
compartment

Grounds

G
100



1995-1998



Front
of
left
front
fender
(headlights)



Fig
.
22
.

G
101



1992-1998



Front
of
right
front
fender

Continued

COMPONENT
LOCATIONS

612
Switches
and
Electrical
Accessories

GENERAL
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
...
.
......
.612-1



Headlight
switch,
replacing



..
.
...
.
.
.
.
.
.
.
.
.
612-5

Foglight
switch,
replacing
....
.
.
.
.
.
.
.
.
.
.
.
.
.
612-5
INTERIOR
SWITCHES
.
.
...
.
.
.
.
.
.
.
.....
612-1



Hazard
warning
switch,
replacing
.
.
.
.
.
.
.
.
.
.612-5
Turn
signal
switch
and
wiper
switch,



Powerwindow
switch,
replacing
.
.
.
...
.
.
.
.
.
612-5
replacing
.
.
.
.
.
.
.
...
.
.
.
.....
.
....
.
.
.
.
612-1



Outside
mirrorswitch,
replacing
.
.
.
.
.....
.
.
.612-6
Ignition
Switch
Assembly
.
.
.
.
.
.
.
.
....
.
...
612-3

Ignition
electrical
switch,
replacing
.
...
.
....
612-3



INTERIOR
LIGHTS
.
.
................
.
..
612-6

Ignition
lock
cylinder,
replacing
.
.
.
.
.....
.
..
612-4



Dome
light,
rear
map
lights,
trunk
light,

Headlight
and
Foglight
Switch
Assembly
.
.
.
.
612-5



replacing
bulbs
.
......
.
.
.
.
.
.
.
.
.
.....
.
.612-7

GENERAL



Turn
signal
switch
and
wiper
switch,

replacing
Thissection
covers
replacement
of
interior
switches
and
accessories
.



The
procedures
for
removing
the
turn
signal
stalk
switch
and
the
wiper
system
stalk
switchare
similar
.
When
working
on
electrical
switches,
always
disconnect
the
negative
(-)
cable
from
the
battery
and
insulate
the
cable
end
to
prevent
accidental
re-connection
.

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.

WARNING
-

The
cars
covered
by
this
manual
are
equipped
with
a
Supplemental
Restraint
System
(SRS)
that
auto-'
matically
deploys
one
or
more
airbags
.
Each
airbag
unit
houses
an
explosive
powerful
charge
.
Any
work
involving
the
SRS
system
should
only
be
per-
formed
byan
authorized
BMW
dealer
.
Making
re-
pairs
without
the
proper
knowledge
and
special
test
equipment
may
cause
serious
personal
injury
.
See
721
Airbag
System
(SRS)

3
.
With
front
wheels
pointed
straight
ahead,
remove
steer-
"
Testing
and
replacement
information
for
the
oil
ores-



¡ng
wheel
.
See
320
Steering
and
Wheel
Alignment
.
sure
switch
is
covered
in
119
Lubrication
System
.

NOTE-

"
Wirfng
diagramscan
be
found
in
Electrical
Wiring
Diagrams
.

"
Fuse,
relay
and
electrical
component
locations
can
be
found
in
610
Electrical
Component
Locations
.

"
Replacement
information
for
thetransmission
gear
position/neutral
safety
switch
is
covered
in
250
Gear-
shift
Unkage
.

INTERIOR
SWITCHES

NOTE
-

To
preventmarring
interior
trim,
wrap
the
tips
of
screw-
drivers
and
pliers
with
tape
beforeprying
out
switches
or
electrical
accessories
.

SWITCHES
AND
ELECTRICAL
ACCESSORIES



612-1

1
.
Disconnect
negative
(-)
cable
from
battery
and
cover
terminal
with
insulating
material
.

2
.
Remove
airbag
unit
from
steering
wheel
.
See
721
Air-
bag
System
(SRS)
.
Store
airbag
unit
in
a
safe
placew¡th
pad
facing
up
.

NOTE
-

To
helo
with
reassembly,
mark
steering
wheel
and
col-
umn
before
disassembly
.

4
.
Remove
trim
panel
from
lower
left
side
of
instrument
panel
.
See513
Interior
Trim
.

INTERIOR
SWITCHES

INSTRUMENT
CLUSTER
....
.
.
.
.
.
...
.
..
620-1

Instrument
cluster,
seif-testing
.
.
.......
.
..
620-1

Instrument
cluster,
removing
and
installing
...
620-1

Instrument
cluster
bulbs,
replacing
.
.
.
.
.
.
...
620-2

GENERAL

This
repair
group
covers
removal
and
installation
of
the
in-
strument
cluster
and
the
Multi-information
Display
(MID)
mod-
ule
.
Bulb
replacement
information
for
these
units
is
also
included
here
.

NOTE
-

A
quick
check
of
the
temperature
gauge
and
its
electri-
cal
circuitis
given
in
170
Radiator
and
Cooling
Sys-
tem
.
Use
this
procedure
to
diagnosea
faulty
temperature
gauge

INSTRUMENT
CLUSTER

When
servicing
the
instrument
cluster,
always
disconnect
the
negative
(-)
cable
from
the
battery
and
insulate
the
cable
end
to
prevent
accidental
re-connection
.

Instrument
cluster,
seif-testing

Severa¡
different
versions
of
the
basic
instrument
cluster
havebeen
fitted
in
E36
cars
.
It
is
possibleto
perform
an
instru-
ment
cluster
test
and
display
system
test
information
.

Some
of
the
information
displayed
by
the
instrument
cluster
during
seif-testing
is
used
for
interna¡
BMW
organizationpur-
poses,
suchasmatching
the
correct
instrument
cluster
com-
ponents
during
parts
replacement
.
Other
functions
test
the
various
instrument
modules
.
Self-test
is
also
used
to
recode
the
instrument
cluster
after
removal
.

In
later
production
vehicles
(1996
and
later)
the
test
results
canbe
downioaded,
via
the
diagnostic
plug,
byan
authorized
BMW
dealertechnician
.

1
.
Turn
ignition
to
"radio"position
.

2
.
Press
and
hold
reset
button
on
trip-odometer
untiltrip-
odometer
display
shows
numerical
codes
.

620
Instruments

4
.
Turn
off
ignition
.

Instrument
cluster,

removing
and
installing

INSTRUMENTS
620-1

GENERAL
.....
.
.
.
.
.
.
.
.
.
.........
.
....
620-1



Odometer
coding
plug,
replacing
.....
.
.
.
.
.
.
620-2

Vehicle
speed
sender,
replacing
...
.
.
.
.
.
.
.
.
620-3

MULTI-INFORMATION
DISPLAY
(MID)
.
.
.
620-4

Multi-Information
Display,
removing
and
installing
..
.
....
.
.........
620-4

3
.
With
each
subsequent
press
of
the
button,
a
different
function
is
tested
.
Some
functions
will
activate
need1e
gauges
.

1
.
Disconnect
negative
(-)
cable
from
battery
and
cover
terminal
with
insulating
material
.

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautionsgiven
at
the
front
of
this
manual
on
page
vi¡¡
.

2
.
Remove
airbag
unit
from
steering
wheel
.
See
721
Air-
bag
System
(SRS)
.
Store
unit
in
a
safe
place
.

WARNING
-

The
airbag
is
an
explosive
devfce
and
should
be
treated
with
extreme
caution
.
Improper
handling
of
the
airbag
could
cause
serious
injury
or
death
.
Store
the
airbag
with
the
horn
pad
facing
up
.
If
stored
facing
down,
accidental
deployment
couldpropel
it
vfolently
into
the
air,
causing
injury
.

3
.
With
front
wheels
pointed
straight
ahead,
remove
steer-
ing
wheel
.
See
320
Steering
and
Wheel
Alignment
.

4
.
Remove
instrument
cluster
retaining
screws
.
See
Fig
.
1
.

5
.
Place
a
towel
over
steering
column
.
Carefully
tilt
top
of
cluster
out
of
dash
panel
.
Unlock
and
disconnect
har-
ness
connectors
from
back
of
cluster
.
See
Fig
.
2
.

INSTRUMENT
CLUSTER

721-2



AIRBAG
SYSTEM
(SRS)

Fig
.
1
.



Airbag
system
components
.

AIRBAG
SENSORSAND
ELECTRONICS

CA
UTION-

"
If
an
airbag
is
activated,
the
following
compo-
nents
must
be
replaced
:
Airbag
with
contact
ring
;
-Pyrotechnic
seat
belt
tensioners
(if
fitted)
;
-SRS
Control
module
;
-Impact
sensors
;
All
airbags
which
did
not
deploy
.

"
Consult
your
BMW
dealer
for
parts
and
service
information
.

TheE36
airbag
system
consists
of
the
following
compo-

nents
:
crash
sensors
(in
earlycars,
through
1993),
an
elec-

tronic
control/monitoring
module
(with
integrated
crash

sensor
in
ZAE
systems),
an
indicator
light
in
the
instrument
panel,
and
inflatable
airbags
equipped
with
gas
generators
in

the
steering
wheel
and
in
the
passenger
side
of
the
instrument

panel
(ZAE
systems)
.

Some
1997
and
al¡
1998
carsalso
have
side-impact
airbags

in
the
front
doors
.

AIRBAG
SENSORS
AND
ELECTRONICS

1.
Crash
sensors
(through
1993)



wheel
2
.



SRS
control
module
in
front
of



5
.



Side-impact
airbags
(1997/98)
glove
compartment
(through



6
.
ZAE
control
module
under
rear
1993)



seat
(from
1994)
3
.



Passenger
side
airbag
unit
in



7
.
Side-impact
airbag
crash
sensors
dashboard
(ZAE
system)



in
door
silis
(1997/98)
4
.



Driver
side
airbag
unitin
steering



8
.



Knee
bolsters

In
addition
to
the
airbags,
the
vehicles
are
equipped
wíth

knee
bolsters
for
extra
protection
.

SRS
Warning
Light
and
Fault
Display

The
airbag
system
utilizes
a
self-diagnostic
control
module

to
detect
and
store
system
faults
.
If
a
fault
is
detected,
the

SRS
indicator
in
the
instrument
cluster
comes
on
and
stays

on
.

When
the
ignition
key
is
tumed
on,
the
indicator
light
will
illu-

minate
for
approximately
4-6
seconds
.
The
illuminated
light

indicates
the
self-testof
the
electronic
control/monitoring

module,
the
ignítors
and
crash-sensorcircuits,
and
the
system

wiring
.
The
airbag
system
should
be
inspected
byan
autho-

rized
BMW
dealer
if
the
indicator
light
does
not
come
on,
ifit

does
not
go
out
in
approximately
4-6
seconds
after
switching

onthe
ignition,
or
if
the
light
comes
on
during
driving
.
If
the

system
has
detected
a
fault,
the
light
will
come
on
and
stay
on
.

GENERAL

This
section
contains
wiring
diagrams
for
1992
through

1998
BMW
3
Series
models
.

WARNING
-

On
cars
equipped
with
airbags,
special
precautions
apply
to
any
electrical
testing
or
repair
.
The
airbag
unit
is
an
explosive
device
and
must
be
handled
with
exterme
care
.
Before
starting
any
work
onan
airbag
equipped
car,
refer
to
the
warnings
and
cau-
tions
in
720
Seatbelts
and
721
Airbag
Systems
(SRS)
.

NOTE-

The
"



gear
position/neutral
safetyswitch
is
also
some-
timesreferred
to
as
the
automatic
transmission
range
switch
.

"
The
EWS
11
system
is
also
sometimes
referred
to
as
the
Driveaway
Protection
System
or
the
electronic
im-
mobilization
system
.

ELECTRICAL
WIRING
DIAGRAMS



ELE-1

Electrical
Wiring
Diagrams

GENERAL
.
.
.
.
.
.
.
.
.
................
.
.
.
ELE-1



Horns



.....
.
.....
.
.
.
....
.
.
.
.
.
...
.
.
ELE-153

Instrument
Panel
.
.
.
.
.
.
..............
ELE-165

ELECTRICAL
WIRING
DIAGRAMS
...
.
.
.
ELE-2



Interior
Lights/Illumination
.............
ELE-211

ABS



..............
.
.
.
.....
.
.....
ELE-117



Lumbar
Control
.
....................
ELE-247

ABS/AST
.............
.
.
.
...
.
.
.
.....
ELE-120



On-Board
Computer
..................
ELE-173

Airbag
(Supplemental
Restraint
System)
..
ELE-140



Park
Ventilation
.
.
.
...........
.
...
.
..
ELE-139

Air
Conditioning
and
Heating
.
.
.
.
.
.
.....
ELE-129



Power
Distribution
......
.
...
.
.
.
.
.
.
.
...
.
ELE-2

Anti-Theft
(Alpine)
..........
.
.
.
...
.
...
ELE-144



Power
Door
Locks
.
.
......
.
.
.
.
.
.
.
.
.
..
ELE-226

Anti-Theft
(EWS
II)
.
........
.
.
.
...
.
...
ELE-150



Power
Mirrors
...
.
.
.
......
.
.
.
.
.
.
.
.
.
..
ELE-241

Body
Computer
Module
.....
.
.....
.
...
ELE-176



Power
Seats
......
.
......
.
.
.
...
.
.
.
..
ELE-243

Charging
System



.
.
................
.
.
.
ELE-67



Power
Sunroof
.
.
.
.
.
.
.
...............
ELE-248

Convertible
Top
.
.
.
.
................
.
.
ELE-253



Power
Windows
.
.
.
.
.
.
.....
.
.........
ELE-231

Cruise
Control
..
.
.
.
...........
.
....
.
.
ELE-112



Radio/Cassette/CD/Speakers
..........
ELE-255

Data
Link
Connector
................
.
.
.
ELE-86



Rear
Window
Defogger
...............
ELE-160

Engine
Cooling
.......
.
.......
.
....
.
.
.
ELE-94



Shift
Interlock
.
.
.
.
.
.
.
.
...............
ELE-110

Engine
Management
...
.
.......
.
....
.
.
.
ELE-70



Starting
....
.
.
.
.
.
...
.
................
ELE-63

Exterior
Lights
........
.
.
.
.
.
.
.
.
.
......
ELE-194



Transmission
Electronics
.
..............
ELE-96
Ground
Distribution
....
.
.
.
.
.
.
.
.
.
.......
ELE-35



Warning
System
:
Chimes
.............
ELE-178

Headlights/Foglights
...
.
.
.
.
.
.
.
.
.
......
ELE-180



Wiper/Washer
.
.....
.
...............
ELE-155

Heated
Seats
........
.
.
.
.
.
.
.
.
.
......
ELE-245

ELECTRICAL
COMPONENT
LOCATIONS

Relayand
fuse
positions,
ground
locations
...........
.
.
.
.
.
.
.
.
.
................
seeRepair
Group
610

CAUTION-

Always
switchthe
ignition
off
and
disconnect
the
negative
(-)
battery
cablebefore
removing
any
electrical
components
.

"
Prior
to
disconnecting
the
battery,
read
the
bat-tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.

"
Connect
and
disconnect
ignition
system
wires,
multiple
connectors
and
ignition
test
equipment
leads
only
while
ignition
is
switched
off
.

-Always
switch
a
test
meter
to
the
appropiate
func-
tion
and
range
before
making
test
connections
.

"
All-Season
Traction
(AST)
is
also
referred
to
as
ASC
or
ASC+T
.

GENERAL