1994 BMW M3 boot

600-2



ELECTRICAL
SYSTEM-GENERAL

CAUTION
-

"
Always
turn
off
the
engine
and
disconnect
the

negative
()
cable
from
the
batterybefore
remov-

ing
any
electrical
components
.
Disconnecting
the

battery
may
erase
fault
code(s)
stored
in
control

module
memory
.
Check
for
fault
codes
using
spe-
cial
BMW
diagnostic
equipment
.

"
Prior
to
disconnecting
the
battery,
read
the
bat-

tery
disconnection
cautions
given
at
the
front
of

this
manual
onpage
viii
.

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

"
Do
not
disconnect
the
battery
with
engine
run-

ning
.

"
Do
not
quick-charge
the
battery
(for
boost
start-
ing)
for
longer
than
one
minute,
and
do
not
ex-
ceed
16
.5
volts
at
the
battery
with
the
boosting
cables
attached
.
Wait
at
feast
one
minute
before
boosting
the
battery
a
second
time
.

"
Do
not
usea
test
famp
that
has
a
normal
incan-

descent
bulb
to
test
circuits
contafning
electronic
components
.
The
high
electrical
consumptionof
these
test
lamps
may
damage
the
components
.

"
Do
not
use
an
analog
meter
.
Use
onfy
a
digital
multimeter
.

"
Many
of
the
solid-state
modules
are
static
sensi-
tive
.
Static
discharge
will
permanently
damage
them
.
Always
handle
the
modules
using
proper
static
prevention
equipment
and
techniques
.

"
To
avoid
damaging
harness
connectors
or
relay
panel
sockets,
use
jumper
wires
with
flat-blade
connectors
that
are
the
same
size
as
the
connec-
tor
or
relay
terminals
.

"
Always
switch
a
digital
multimeter
to
the
appropri-
ate
function
and
range
before
making
test
con-
nections
.

"
Do
not
tryto
start
the
engine
of
a
carwhich
has
been
heated
above176°F
(80°C),
(for
example,
in
a
paint
dryingbooth)
.
Allow
it
to
cool
to
normal
temperature
.

"
Disconnect
the
battery
before
dolng
any
electric
welding
on
the
car
.

"
Do
not
wash
the
engine
while
it
is
runnfng,
or
any-
time
the
ignition
is
switched
on
.

WIRING
DIAGRAMS

Electrical
Test
Equipment

Many
of
the
electrical
tests
described
in
this
manual
call
for

measuring
voltage,
currentorresistanceusing
a
digital
multi-

meter
(DMM)
.
Digital
meters
are
preferred
for
precise
mea-

surements
and
for
electronics
work
because
they
are
generally
more
accuratethan
analog
meters
.
The
numerical

display
is
alsoless
likely
to
be
misread,
since
there
is
no
nee-

dle
position
to
be
misinterpreted
by
reading
at
an
angle
.

An
LED
test
light
is
a
safe,
inexpensive
tool
that
can
be
used

to
perform
many
simple
electrical
tests
that
would
otherwise

require
a
digital
multimeter
.
The
LED
indicates
when
voltage

is
present
between
anytwo
test-points
in
a
circuit
.

CA
UTION-

"
Choose
test
equipment
carefully
.
Use
a
digital

multimeter
with
at
leadt
10
megaohm
input
im-

pedance,or
an
LED
test
light
.
An
analog
meter
(swing-need1e)
ora
test
light
with
a
normal
incan-
descent
bulb
may
draw
enough
current
to
dam-
age
sensitive
electronic
components
.

"
An
ohmmeter
must
not
beused
to
measure
resis-
tance
on
solidstate
components
suchas
controlunits
or
time
delay
relays
.

"
Always
disconnect
the
battery
before
making
re-

sístance
(ohm)
measurements
on
the
circuit
.

WIRING
DIAGRAMS

The
wiring
diagrams
shown
in
Electrical
Wiring
Diagrams

have
been
specially
designed
to
enable
quick
and
efficientdi-

agnosis
and
troubleshooting
of
electrical
malfunctions
.

Wiring
Codes
and
Abbreviations

A
lot
of
information
is
included
in
each
wiring
diagram
if
you
know
how
to
read
them
.
Wire
colors
in
the
diagrams
are
ab-

breviated
.
Combined
color
codes
indicate
a
multi-colored
wire
.
For
example
the
code
BLU/RED
indicates
a
Blue
wire

with
a
Red
stripe
.

Many
electrical
components,
connectors,
fuses,
and

ground
locations
are
identified
using
a
unique
number
.
Each

of
there
numbers
corresponds
to
a
particular
part
in
the
circuit
commonly
found
in
Electrical
Wiring
Diagrams
.

Headlight
switch,
replacing

1
.
Remove
left
side
dash
insert
and
disconnect
harness
connector
to
headlight
switch
.
See
Fig
.
10
.

3
.
Remove
nut
mounting
switch
to
dash
insert
.
See
Fig
.
11
.

Fig
.
11
.
Headlight
switch
mounting
nut
(arrow)
.

4
.
Pull
switch
out
from
housing
.

SWITCHES
AND
ELECTRICAL
ACCESSORIES



612-5

0012558

5
.
Installation
is
reverse
of
removal
.
Align
new
switch
to
dash
insert
.
See
Fig
.
12
.

Tightening
Torque

"
Headlight
switch
retaining
nut
.
......
2
Nm
(18
in-lb)

Foglight
switch,
replacing
0012559
Fig
.
10
.
Removing
headlightswitch
electrical
harness
connector



1
.
Remove
left
side
dash
insert,
as
described
earlier,
and
(arrow)
.



remove
foglight
switch
harness
connector
.

2
.
PA
off
headlight
switch
knob
.
Wrapping
adhesive
tape
aroundknob
facilitates
removal
.



spring
tabs
together
.

0012560
Fig
.
12
.
Fit
groove
on
headlightswitch
into
switch
bezel
ondash
insert
(arrows)
.

2
.
Slide
foglight
switch
out
of
dash
insert
by
sqúeezing

3
.
Installation
is
reverse
of
removal
.

Hazard
warning
switch,
replacing

1
.
Unclip
shift
boot
and
lift
up
from
shift
lever
console
.
Carefully
remove
insulation
pad
.
See
250
Gearshift
Linkage
.

2
.
Working
underneath
center
console,
push
hazard
warning
switch
up
and
out
of
console
with
your
fingers
.

3
.
Disconnect
harness
connector
from
switch
.

4
.
Installation
is
reverse
of
removal
.

Power
window
switch,
replacing

1
.
Unclip
shift
boot
and
lift
up
from
shift
lever
console
.
Carefully
remove
insulation
pad
.
See250
Gearshift
Linkage
.

2
.
Working
underneath
center
console,
push
window
switch
up
out
of
console
with
your
fingers
.
See
Fig
.
13
.

3
.
Disconnect
harness
connector
from
switch
.

4
.
Installation
is
reverse
of
removal
.

INTERIOR
SWITCHES

6
INDEX

Ignition
system
general
information
120-1basictroubleshooting
principies
120-3camshaft
position
(CMP)
sensor
120-
6

camshaft
positíon
(CMP)
sensor,
replacing
(4-cylinder
engine)
120-6camshaft
position
(CMP)
sensor,
replacing
(6-cylinder
engines)
120-7
checking
for
spark
120-3
crankshaftposition/rpm
sensor
120-5
crankshaft
position/rpm
sensor,
testing/replacing
(front
mounted
sensor)
120-6
crankshaft
positíon/rpm
sensor,
testing
(rear
mounted
sensor)
120-6
disabling
ignition
system120-2
ignition
coil,
testing
and
replacing
(4-
cylinder
engines)
120-3
ignition
coil,
testing
and
replacing
(6-
cylinder
engines)
120-4
ignítion
firing
order
120-7
ignition
system
diagnostics
120-3
ignition
system
schematics
120-7
ignition
system
service
120-3knock
sensors,
replacing
120-7warnings
and
cautions
120-2
Inspectíon
I
and
Inspection
II
See
Maintenanceprogram
Instrumentpanel
See
interior
trim
Instruments
general
information
620-1
instrument
cluster,
removinglinstalling
620-1
instrument
cluster,
self-testing
620-1
instrument
cluster
bulbs,
replacing
620-2
multi-information
display
(MID),
620-4
multi-information
display
(MID),
removing/installing
620-4
odometer
coding
plug,
replacing
620-
2
vehicle
speed
sensor,
replacing
620-3
Intake
manifold
4-cylinder
engíne,
removing
113-3
6-cylinder
engine,
removing
113-11
See
alsoCylinder
head
removal
and
installation
Intake
air
temperaturesensor
See
Fuel
injection
Interior
trim
general
information
513-1
center
console,
removing/installing
513-1
dashboard,
removing/installing
513-3
glove
compartment,
removing/
installing
513-2
lower
left
dash
panel,
removing/
installing
513-2

J

Jump
startíng
010-12

K

Knock
sensor
See
Ignition
system
L

Leather
upholstery
See
Maíntenance
program
Leve¡
sender
See
Fuel
pump
Lubrication
system
general
information
119-1
oil
pan,
removing/installing
(4-cylinder
engines)
119-2
oil
pan,
removing/installing
(6-cylinder
engine,
1992models)119-4
oil
pan
119-2
oil
pan,
removing/installing
(6-cylinder
engine,
1993
and
later
models)
119-6
oil
pressure,
checking
119-1
oil
pressure
warningsystem,
testing
119-2
oil
pump
119-8
oil
pump,
removing/installing
(4-cylinder
engine)
119-8
oil
pump,
removing/installing
(6-cylinder
engine)
119-9
troubleshooting
119-1

M

Maíntenance
program
general
information
020-2
accelerator
and
throttle
linkage
020-13
air
filter,
replacing
020-11
automatic
transmission
fluid
020-8
automatic
transmission
service
020-18
battery,
checking
and
cleaning
020-12
battery,
replacing
020-12
BMW
service
indicator
020-2
body
and
hinges,
lubricating
020-19
brake
fluid
020-9
brake
fluid,
replacing
020-17
brake
pad/rotor
wear,
checking
020-17
brake
system,
inspecting
020-17
clutch
fluid,
checking
020-19
cooling
system
service
020-14
drive
axle
joint
boots,
inspecting
020-19
engine
coolant
(anti-freeze)
020-9
engine
drive
belts
020-13
engine
oil,
checking
leve¡
020-9

Maintenance
program
(cont
.)
engine
oil
and
filter,
changing020-9engine
oil
service
020-9
exhaust
system,
inspecting
020-18
exterior
washing020-20
final
drive
gear
oil
020-9
final
drive
oil
level,
checking
020-18
front
suspension
and
steering

linkages,
inspecting
020-18
fuel
filter,
replacing
020-16
fuel
tank
and
fuel
lines,
inspecting
020-19
¡dle
speed
020-12
inspection
I
and
inspection
11
020-2
interior
care020-20
leather
upholstery
and
trim
020-20
maintenance
tables
020-3
manual
transmission
fluid,
checking
and
filling
020-18manual
transmission
fluid
020-8
manual
transmission
service
020-18oxygensensors
020-15
parking
brake,
checking
020-17
polishing
020-20
poly-ribbed
belt,
replacing
020-13
power
steering
fluid
020-9
power
steering
fluid,
checking
leve¡
020-14
rear
suspension,
inspecting
020-18
resetting
service
indicator
020-3
seat
belts
020-20
spark
plugs,
replacing
020-11
special
cleaning
020-20
tires,
checking
inflation
pressure
020-17
tires,
rotating
020-17
v-belt,
replacing
020-13
washing
chassis
020-20waxing020-20
windshield
wiperblade
maintenance
020-19
wheels,
aligníng
020-17
Manual
transmission
See
also
Maintenance
program
See
also
Transmission-general
general
information
230-1
back-up
light
switch,
replacing
230-2
inputshaft
sea¡,
replacing
(transmission
installed)
230-5
output
shaftsea¡,
replacing
(transmission
installed)
230-4
selector
shaft
sea¡,
replacing
(transmission
installed)
230-3
transmission
fluid,
replacing
230-2
transmission
fluidlevel,
checking
230-2
transmission
fluid
service
230-1
transmission
removal
and
installation
230-5
transmission,
removing/installing
230-
6
transmission
service
230-2
Mass
air
flow
sensor
See
Fuel
Injection

N

WARNING

Your
common
sense,
good
judge-
ment,
and
general
alertness
are
cru-
cial
to
safe
and
successful
service
work
.
Before
attempting
any
workonyour
BMW,
read
the
warnings
and
cautions
on
page
vi¡
and
the
copyright
page
at
the
front
of
the
manual
.
Review
these
warningsand
cautions
each
time
you
prepare
to
work
on
your
BMW
.
Please
also
read
any
warnings
and
cautions
that
accom-
pany
the
procedures
in
the
manual
.

Master
cylinder
See
Brakes
See
also
Clutch
Mechanical
troubleshooting
See
Engine-general
Microfilter
See
Air
conditioning
Mirror
See
Exterior
trim,
bumpers
Muffler

See
Exhaustsystem
Multi-information
display
(MID)
See
Instruments

Neutral
safetyswitch
See
Gearshift
linkage

O

Oil,
changing
See
Maintenance
program
Oil
panSee
Lubrication
system
Oil
pressure
See
Lubrication
system
Oil
pump
See
Lubrication
systemOn-board
diagnostics
(OBD)
See
Engine-general
See
alsoFuel
injection
See
also
Ignition
system
On-board
trip
computer
See
Multi-information
display
620-4
Oxygen
sensor
See
Engine-general
See
alsoFuel
injection
See
also
Maintenance
program

P

Parking
brake
See
Brakes
See
also
Maintenance
program
Parts
See
Fundamentals
for
the
do-it-
yourself
owner
Poly-ribbed
belt
See
Maintenance
program
Power
steering
See
Steering
and
wheel
alignment
Power
steering
(luid
See
Maintenance
program

R

Radiator
See
Cooling
system
Radio
general
information
650-1audio
system
650-1
radio
connector
650-6
removing/installing
650-2speakersdoor
panel
speaker,
removing/
installing
650-5
left
footwell
speaker,
removing/
installing
650-3
rear
speaker,
removing/installing
650-5
right
footwell
speaker,
removing/
installing
650-4Rearsuspension
See
also
Maintenance
program
general
information
330-1
coil
spring,
removing/installing
330-4
CV
boot,
replacing
330-8
drive
axle,
removing/installing
330-6
drive
axles
330-6
final
drive
carrier
330-12
final
drive
carrier,
removing/installing
330-12
lower
control
arm,
removing/installing
330-12
rear
shock
absorber,
removing/
installing
330-3
rear
suspension
arms
330-9
ride
heíght
330-1
shock
absorbers
and
springs
330-2
trailing
arm,
removing/installing
330-10
trailing
arm
bushing,
replacing
330-11upper
control
arm,
removing/installing
330-12
rear
wheel
bearing,
replacing
330-5

rear
wheel
bearings
330-4
Rear
view
mirror
See
Exterior
trim,
bumpers
Receiver/drivr
See
Air
conditioning
Relays
See
Electrical
component
locations

INDEX
7

Ride
height
See
Front
suspension
or
Rearsuspension
Ring
antenna
See
Central
locking
and
anti-theft
Roof
See
Convertible
top
See
also
Sunroof
Roundel
See
Exterior
trim,
bumpers

S

Seat
belts
general
information
720-1
automatic
front
seat
belt
lock
tensioners
720-2
center
rear
lap-belt,
removing/
installing
720-5
front
seat
beltreel,
removing/installing
720-3
mechanical
spring
tensioner,
disarming
720-2
rear
seat
belt,
removing/installing
(fixed
seat
back
models)
720-4
rear
seat
belt,
removing/installing
(fold-down
seat
back
models)
720-5Seats
general
information
520-1
front
seats520-1
manual
front
seat
assembly
520-3
power
front
seat
assembly
520-4
removing/installing
520-1
rear
seats
520-5
rear
seat
cushion
and
backrest,
removing/installing
(fixed
seat
backmodels)
520-5
rear
seat
cushion
and
backrest,
removing/installing
(fold-down
seat
back
models)520-5
rear
seat
backrest
side
section,
removing/installing
(fold-down
seat
back
models)520-6
Shiftinterlock
See
Gearshift
linkage
Shiftlever
See
Gearshift
linkage
Shíftlock
See
Gearshift
linkage
Shock
absorber
See
Front
suspension
See
also
Rear
suspension
Side-impact
airbag
See
Airbag
system
(SRS)
Slave
cylinder
See
Clutch
Service
indicator
See
Maintenanceprogram
Solenoid
See
Battery,
starter,
alternator
Spark
See
Ignition
system
Spark
plugs
See
Maintenance
program