1997 BMW 328i electrical system general

Wheel
brake
caliper

Electronic
control
module
Fig
.
4
.



Schematic
representation
of
ABS
.

SUSPENSION,
STEERING
ANDBRAKES-GENERAL



300-3

Fig
.
3
.



Schematic
view
ofdual
circuit
brakes
with
4-channel
ABS
.

ing
adverse
conditions
.
It
automatically
adjusts
brake
system
hydraulic
pressure
at
each
wheel
to
prevent
wheel
lock-up
.

The
system's
main
components
arethe
wheel
speed
(pulse)
sensors,
the
ABS
control
module,
and
the
hydraulic

control
unit
.
See
Fig
.
4
.

Warning
lamp

u
Master

Whee

_

l
speed



I-lydraulic



cylinder

sensor



control
unit



0012135

UNI

The
wheel
speed
sensors
continuously
send
wheel
speed
signals
to
the
control
module
.
See
Fig
.
5
.
The
control
module
compares
these
signals
to
determine,
in
fractions
of
a
second,
whether
any
of
the
wheels
areabout
to
lock
.
If
any
wheel
is
nearing
a
lock-up
condition,
the
module
signals
the
hydraulic
unit
to
maintain
or
reduce
pressure
at
the
appropriatewheel(s)
.
Pressure
is
modulated
by
electrically-operated
sole-

noid
valves
in
the
hydraulic
unit
.

Fig
.
5
.



ABS
wheelspeed
sensor
.

0006563

INTEGRATED
SYSTEMS

320
Steering
and
Wheel
Alignment

GENERAL
...
.
.
.
...
.
....
.
.
.
.
.
.
.
.
.
...
.
.
320-1



Outer
tie
rod
end,
replacing
.
...
.
.
.
.
.
.
.
...
.
320-4

Tie
rod,
replacing
.
.
.
.
.
.
.
.......
.
.
.
.
.
...
.
320-5

STEERING
WHEEL



320-1

Steering
wheel,
removing
and
installing
.....
320-1



WHEEL
ALIGNMENT
.
.
.
.........
.
.....
.320-5

POWER
STEERING
SYSTEM
.
.
.
.
.
.
.....
320-2



Front
Toe-in
and
Toe
Difference
Angle
.
.
...
.
320-6

Power
steering
pump,



Rear
Toe-in
.
.
.
.
.
.
.
...
.
................
320-6
removing
and
installing
..
.
.
.
.
.
.
.
.
.
.....
320-2



Wheel
Alignment
Specifications
.....
.
......
320-6

Power
steering
system,
bleeding
and
filling
.
.
320-3

STEERING
GEAR
.
.
.
.
...
.
.
.
.
.
.
.
.
.
.....
320-3

Steering
gear
rack,

removing
and
installing
.
...
.
..
.
..
..
..
.
..
.
320-3

GENERAL



STEERING
WHEEL

This
repair
group
covers
servicing
of
the
mechanical
and



The
BMW
E36
is
equipped
with
an
SRS
airbag
mounted
in

hydraulic
components
of
the
steering
system,
including
wheel



the
steering
wheel
.
Improper
handling
of
the
airbag
could
alignment
information
.



cause
serious
injury
.
The
airbag
is
an
explosivedevice
and

should
be
treated
with
extreme
caution
.
Always
follow
the
air-

The
variable-assist
power
steering
system
consistsof
an



bag
removal
procedure
as
outlined
in
721
Airbag
System

engine-driven
hydraulic
pump,
a
rack-and-pinion
steering



(SRS)
.

gear
assembly
with
an
integral
hydraulic
control
valve,
and

connecting
linkage
to
the
road
wheels
.



WARNING-

"
The
BMW
Supplemental
Restraint
System
(SRS)
At
lowspeeds,
maximum
power
assist
is
provided
to
ease



is
complex
and
special
precautions
must
be
ob-

parking
and
city
driving
.
At
high
speeds,
assist
is
reduced
to



served
when
servicing
.
Serious
injury
may
result

ensure
stability
.
The
power
steering
system
varies
assist



if
system
service
is
attempted
by
persons
unfa-

based
on
engine
speed
.



miliar
with
the
BMW
SRS
and
its
approved
ser-
vice
procedures
.
BMW
specifies
that
all

ING-



inspection
and
service
shouldbe
performed
by
WARN
an
authorized
BMW
dealer
.
"
Do
not
reuse
self-locking
nuts
.
They
are
de-signed
to
beused
only
once
and
may
failif
re-



"
BMW
Supplemental
Restraint
Systems
(SRS)
used
.
Always
replace
them
with
new
locking
nuts
.



are
equipped
with
a
back-up
power
supply
inside
the
SRS
control
module
.
A
10minute
waiting
"
Do
not
ínstall
bolts
and
nuts
coated
with
under-



shouldbe
observed
after
the
battery
cable
has
coating
wax,
as
correct
tightening
torque
cannot



been
disconnected
.
This
will
allow
the
reserve
be
assured
.
Always
clean
the
threads
with
sol-



power
supply
to
discharge
.
vent
before
installation,
or
install
new
parts
.

"
Do
not
attempt
to
weldor
straighten
any
steering
components
.
Always
replace
damaged
parts
.

NOTE-

For
information
on
steering
column-mounted
switches
and
the
ignition
lock,
see
612
Switches
and
Electrical
Accessories
.

STEERING
AND
WHEEL
ALIGNMENT



320-1

Caster
and
Camber
.
.
.
.
.
...........
.
....
320-5

TABLES

a
.
Front
Wheel
Alignment
Specifications
.
...
.......
320-6
b
.
Rear
Wheel
Alignment
Specifications
.
...
.......
320-6

Steering
wheel,
removing
and
installing

1
.
Center
steering
wheel
.
Make
sure
front
wheelsare

pointed
straight
ahead
.

2
.
Disconnect
negative
(-)
cable
from
battery
and
cover

terminal
with
insulating
material
.

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

STEERING
WHEEL

400-
4
BODY-GENERAL

INTERIOR
EQUIPMENT

E36
interiors
have
a
unique
character,
with
a
combínation
of
sporty
features
and
innovative
design
.
Al¡
body
versions
were
made
in
a
wide
choice
of
interior
and
exterior
colors
.
New

colors
with
matching
leather
and/or
fabric
upholstery
were
in-
troduced
for
each
model
year,
including
light-alloy
wheels
in
new
designs
.

Driving
comfort
is
enhanced
by
power
steering,
tilt
steering
wheel
(optional),
height-adjustable
front
seats,
and
electrical-
ly
adjustable
and
heated
rear-view
mirrors
.
Inside
thecar
there
are
reading
lights
at
four
seating
positions
.

Seats
and
Seat
Belts



NOTE-

Theseat
base
usedon
cars
with
pyrotechnic
seatbelt

Anatom¡cal
ly-correct
seats
are
constructed
from
polyure-



tensioners
is
not
interchangeable
with
the
earlier
seat

thane
foam
containing
areas
or
"zones"
of
different
firmness
.



base
.

The
seat
bases
have
steel
springs
for
added
support
and
strength
.
The
power
seats
are
provided
with
conveniently
lo-



Instruments
and
Controls
cated
switches
along
the
outside
edge
of
the
seat
.
Heated
seats
are
an
option
in
all
models
.
See
520
Seats
for
more
de-



Everything
in
the
interior
passenger
compartment
essential
tails
.



to
the
driver
is
logically
grouped
and
easy
to
reach
.
Al¡
instru-
ments
and
controls
havebeen
arranged
ergonomically
and
The
M3
sport
seat
is
shown
in
Fig
.
3
.



are
fully
integrated
into
the
overall
design
of
the
vehicle
.

Fig
.
3
.



M3
sport
seat
.

INTERIOR
EQUIPMENT

0013195

The
early
E36
cars
areequipped
with
a
single
(driver
side)
airbag
in
the
steering
wheel
.
Startingwith
the
1994
models,
a
dual
airbag
Supplemental
Restraint
System
has
been
stan-
dard
equipment
.
Side-impact
airbags
in
the
front
doors
are
op-
tional
in
1997
4-door
cars
and
standard
equipment
in
all
1998
models
.

Through
1996,
E36
seatbelts
were
equipped
with
BMW's
original-designspring
tensioners
.
In
1997,
the
seat
base
de-
sign
was
modified
to
accommodate
a
pyrotechnic
(explosive
charge)
seatbelt
tensioner
.
Both
types
of
tensioners
arede-
signed
to
automatically
tension
the
belts
by
about2
inches(55
mm)
in
the
event
of
a
collision
.

The
padded
dashboard
houses
the
instrument
cluster
and
the
ventilation
and
heating
system
.
The
instrument
cluster
uses
large
easy-to-read
analog
instruments
and
is
removable
as
a
unit
without
removing
the
dashboard
.
The
Service
Inter-
val
Indicator
(SII)
will
remind
the
driver
when
thecar
requires
service
.
See
620
Instruments
.

The
Multi-Information
Display
(MID)
unit
in
thecenter
of
the
dashboard
comes
in
a
variety
of
four
configurations,
the
most
advanced
being
the
On-Board
Computer
(OBC)
.
See
Fig
.
4
.

Al¡
versions
of
the
MID
have
a
clock
and
calendar
.
In
addi-
tion,
different
versions
areequipped
with
a
"check
control,"

display
for
fuel-economy
information
and
system
warnings
.
Consult
the
owner's
manual
for
fui¡
operating
instructions
.

Ambient
temperaturelclock

MÍM
Aa
.Mi}rm
-Mil"
IMua~naa~u~itacar
"
za
.~

Central
Body
Electronics

0013028

Fig
.
4
.



Different
versionsof
Multi-information
Display(MID)
installed
in
E36
cars
.

The
E36
cars
are
equipped
with
a
sophisticated
centralized

body
electric/electronics
plan
.
The
system
is
self-diagnostic

and
incorporates
many
functions
into
a
single
control
module
.

The
consolidation
of
several
systems
into
a
single
control

module
minimizes
power
requirements
and
the
incorporation

of
the
diagnostic
link
results
in
more
efficient
and
accurate

troubleshooting
.

Self-diagnostic
codes
are
accessible
electronically
through

the
data-link
connector
in
the
engine
compartment
.
See610

Electrical
Component
Locations
.

BODY-GENERAL
400-
5

Two
versions
of
central
body
electronics
are
used
depend-

ing
on
model
year
.

1992
and
1993
models
are
equipped
with
a
central
locking

module
(ZVM)
which
incorporates
control
of
the
following
sys-

tems
:

"Interiorlighting
"
Central
locking
with
double
lock
feature

"
Output
relays
for
powerwindows
and
sunroof

"
Electronic
power
protection

E36
cars
since
the
1994
model
year
are
equipped
with
ZKE

IV
.
This
is
an
electronic
comfort
and
convenience
system
that

includes
the
following
additional
features
:

"
One
touch
up/down
power
window
operation

"
Power
window
and
sunroof
closure
from
driver
or
pas-

sengerdoor
lock

"
Vehicle
locking
or
unlocking
from
the
trunk
lock
.

Other
features
of
the
system
are
discussed
in
515
Central

Locking
and
Anti-Theft
.

Electronic
Immobilization
System

Beginning
in
model
year
1994,
all
E36
vehicles
incorporate

adriveaway
protection
system
regardless
of
whether
the
vehi-

cle
is
equipped
with
a
BMW
Alarm
System
or
an
On-Board

computer
.
Two
types
of
factory
systems
were
installed,
de-
pending
on
vehicle
production
date
.

On
the
early
system
(model
year
1994
up
to
January
1995),

the
ignition
and
fuel
injection
functions
are
disabled
whenever

the
vehicle
is
locked
in
the
double
lock
mode
.
This
is
referred

lo
as
EWS
or
EWS
I
.

Beginning
in
January
1995,
the
driveaway
protection
sys-

tem
was
upgraded
to
a
more
sophisticated
system,
called

EWS
II
.
This
system
uses
a
wireless
communication
link
be-

tween
a
transponder
chip
in
the
ignition
keyand
the
ring
an-

tenna
surrounding
the
ignition
switch
.
The
EWS
II
control

module
blocksthe
starting
of
the
vehicle
unlessthe
correct

coded
ignition
key
is
used
.

For
further
information
about
drive
away
protection
sys-

tems,
see
515
Central
Locking
and
Anti-Theft
.

INTERIOR
EQUIPMENT

515
Central
Locking
and
Anti-Theft

GENERAL
.....
.
.
.
.
.
.
.
..:
.
.
.
......
.
.
.
.
515-1



Luggage
compartment
locking
actuator,
removing
and
installing
.
.
.
.
.
...........
.
515-6

DOOR
HANDLES
AND
LOCKS
.........
515-1



LOCKING
SYSTEM
AND
Front
door
lock,
removing
and
installing
....
.515-1



ELECTRONIC
IMMOBILIZATION
......
.515-7
Front
door
handle,
removing
and
installing
...
515-3

Rear
door
lock,
removing
and
installing
.....
515-4



Central
Locking
System(ZVM)
.
.
.
.
.......
.
515-7

Rear
door
handle,
removing
and
installing
...
515-5



Central
Body
Electronics
(ZKE
IV)
.
.
.......
.515-8

Electronic
Immobilization
System
(EWS)
.
.
.
.
.515-8
Door
striker,
rep
lacing
.
.
.
.
.
.
.
.
.
..........
515-6



EWS
II
control
module,
re
lacin



515-10

LOCKING
ACTUATORS
.
.
.
.
.
.
..........
515-6



Ring
antenna,
replacing
.
.
.
.
.
.
.
.
.
.
...
.
.
.
.
515-10

Door
Locking
Actuator
.
.
.
.
.
.
.
.
..........
515-6



EWS
II
transmitter/receiver
module,

replacing
...........
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
515-11

GENERAL

This
section
covers
repair
information
for
the
central
locking

and
the
anti-theft
systems
.
Keep
in
mind
that
E36
cars
are



CA
UTION-

equipped
with
sophisticated
and
self-diagnostic
electrical
sys-



Prior
to
disconnecting
the
battery,
read
the
battery

tems
.
When
experiencing
malfunctions
relatinglo
the
central



disconnection
cautions
given
at
the
front
of
this

locking
or
the
anti-theft
system,
it
is
recommended
that
the



manual
onpage
vi¡¡
.

systembe
diagnosed
using
the
BMW
service
tester
(DIS)
.

This
advanced
diagnostic
tool
can
usually
pinpoint
electrical



NOTE-
faults
quickly
and
safely
.
Consult
an
authorized
BMW
dealer
.
In
some
models
covered
inthis
manual,
it
is
not
essen-
tial
to
remove
the
side-impact
airbag
to
access
intemal

NOTE-



door
components
.
However,
the
procedure
is
recom-

Additional
general
electrical
information
can
be
found



mended
for
safely
reasons
.

i
n
610
Electrical
Component
Locations
and
Electri-
cal
Wiring
Diagrams
.



4
.
Disconnect
harnessconnector
from
window
motor
to

DOOR
HANDLES
AND
LOCKS

Front
door
lock,
removing
and
installing

1
.
Remove
front
door
panel
and
vapor
barrier
asde-

scribed
in
411
Doors
.

WARNING
-

Some
1997
and
all
1998
cars
are
fitted
with
side-im-

pact
airbags
in
the
front
doors
.
When
servicing
the
door
locks
on
cars
with
front
side-impact
airbags,
al-
ways
disconnect
the
negative
(-)
battery
terminal
.
See721
Airbag
System
(SRS)
forcautions
andpro-
cedures
relating
to
the
airbag
system
.

2
.
Raise
door
window
completely

CENTRAL
LOCKING
AND
ANTI-THEFT



515-1

3
.
On
cars
with
side-impact
airbags,
disconnect
negative
(-)
cable
from
battery,
then
remove
airbag
module
.

prevent
accidental
operation
.

5
.
On
4-door
cars
:
Peel
back
rubber
window
guide
from

reas
guide
rail
:
Remove
guide
rail
mounting
boltat
bot-

tom
.
Unclip
any
wiring
from
guide
rail
and
pull
guide
rail

downward
and
remove
from
door
.
See
Fig
.
1
.

NOTE
-

The
top
of
the
guide
rail
is
"hooked"
to
the
doorsheet
metal
.

6
.
Remove
inside
door
handle
retaining
screw
.
Discon-

nect
inside
handle
from
linkage
and
remove
.
See
Fig
.

2
.

7
.
Cut
wire
ties
and
remove
door
lock
electrical
harness
con-

nector
.
Remove
door
lock
mounting
screws
.
See
Fig
.
3
.

8
.
Working
inside
door,
disconnect
outside
door
handle

and
lockcylinder
linkage
from
door
lock
.
Remove
lock

from
inside
door
.
See
Fig
.
4
.

DOOR
HANDLES
AND
LOCKS

GENERAL
.
...
.
.
.
......
.
.
.
.
.
.
.
.
.
......
541-1



Visor
Latch
Plate
.....
.
....
.
.
.
.
.
...
.
...
.541-4

Visor
Latch
..
.
............
.
.
.
..........
541-4

MANUAL
CONVERTIBLE
TOP
.
.
.
.
...
.
..
541-1



Visor
Latch
Motor
...
.......
.
.
.
..
........
541-5

Visor
Latch
Plate
.
.
......
.
.
.
...
.
.
.
.
.
.
.
..
541-1



Convertible
top
and
frame,
replacing
........
541-5

VisorLatch
.
.
.
.
.
.
.
.
..........
.
.....
.
.
.541-1



Convertible
top
drive
motor,
replacing



......
541-7

Convertible
Top
Lid
Release
Mechanism
.
.
.
.
541-2



Convertible
Top
Emergency
Operation
.....
.541-7

Convertible
top
and
frame,
replacing
....
.
.
.
541-2



Convertible
Top
Lid
.
.
.
.
...........
.
.....
541-9

POWER
CONVERTIBLE
TOP
.
.
.
.
....
.
.
.
541-2



ROLLOVER
PROTECTION
SYSTEM
..
.
.
541-9

FrontLatching
Mechanism
.
.
.
.
.
.
.
.
......
.
541-4

GENERAL

The
convertible
top
comes
in
three
versions
:
a
manually
op-erated
top,
a
semi-automatic
power
top
and
a
fully
automatic
power
top
.

NOTE-

The
convertible
top
control
module
(CVM)
is
located
behind
the
left
rearside
trim
panel
.
For
the
location
of
other
convertible
top
electric
components
see610
Electrical
Component
Locations
.

The
rear
window
in
the
convertible
models
is
made
of
a
strong,
flexible
vínyl
which
is
available
separately
.
Replace-

ment
of
the
rear
window
is
not
covered
in
this
manual
.

The
left
and
right
visor
latch
plates
can
be
accessed
by
re-
moving
the
trim
and
moldings
around
the
sides
and
top
of
the

windshield
.
Each
latch
is
secured
to
thetop
of
the
windshield

usingthree
bolts
.
Latch
position
is
adjusted
as
follows
:

541
Convertible
Top

CONVERTIBLE
TOP



541-1

"
Loosen
bolts

"
Latch
top

"
Align
top

"
Retighten
bolts
.
See
Fig
.
1
.

BMW
has
designed
a
specialbattery
tray
for
the
convertible

which,
in
conjunction
with
the
mass
of
the
battery
in
the
lug-

gage
compartment,
serves
to
dampen
convertible
body
flex
ing
and
vibration
.



Fig
.
1.



Visor
latchplate
is
held
to
top
of
windshieldwith
three
bolts
(arrows)
.

CAUTION-

The
E36
convertible
requires
a
specialbattery



VisorLatch
which
is
designed
for
constant
vibration
.
A
battery
not
designed
forthis
will
fa¡¡
much
earlier
.



Check
for
ease
of
release
and
locking
of
convertible
top
front
latches
.
Height
of
a
latch
can
be
changed
by
using
the
adjusting
screw
.
To
change
latch
tension,
it
is
necessary
to
re-
MANUAL
CONVERTIBLE
TOP



move
the
trim
on
the
front
bow
of
thetop
.
The
ball-joint
pull-rod
length
can
then
be
adjusted
.
Lubricate
latch
if
necessary
.
See

Visor
Latch
Plate



Fig
.
2
.

MANUAL
CONVERTIBLE
TOP

Convertible
top
drive
motor,
replacing



5
.
Working
in
convertible
top
storage
compartment
be-
hind
driver's
seat,
remove
convertible
top
linkage
rods
1
.
Open
convertible
top
partially,
stopping
when
convert-



from
top
of
motor
.
Refer
to
Fig
.
11
.
ible
top
lid
is
fully
upen
.
Remove
lid
.

2
.
Release
luggage
compartment
lock-out
by
pressing
on
microswitch
in
right
convertible
top
lid
latch
.
See
Fig
.

14
.

0012745

Fig
.
14
.
Rightside
convertible
top
lid
latch
.
Arrow
points
to
location
of
luggage
compartment
lock-out
microswitch
.

3
.
Open
luggage
compartment
.
Remove
trim
and
inner

lining
from
left
side
of
compartment
.

4
.
Disconnect
electrical
harness
connectors
at
top
motor
.

Release
emergency
release
cable
from
lever
.
Push
le-

ver
up
to
release
motor
.
See
Fig
.
15
.

uu12759

Fig
.
15
.
Convertible
top
motor
(A)
and
release
lever
(B)
in
luggage

compartment
.

CONVERTIBLE
TOP



541-
7

6
.
Remove
four
fastenersholding
motor
to
body
and
re-

move
motor
through
luggage
compartment
.
See
Fig
.

16
.

0012761

Fig
.
16
.
Convertible
top
motor
mountingscrews
(arrows)
.
Gasket
(A)
mustbe
renewed
when
motor
is
replaced
.

7
.
Installation
is
reverse
of
removal
.
Keep
the
following
in

mind
:

"
Replace
sealing
gasket
between
top
of
motor
and

body
.

"
Securemotormountingscrews
with
Locktite
®
270
or
equivalent
.

Tightening
Torque

"
Convertible
top
motor
to
body

mountingscrews
...
...
.
.
.........
10
Nm
(7
.5
ft-Ib)

Convertible
Top
Emergency
Operation

A
malfunction
in
the
electrical
system
or
another
fault
in
the

convertible
top
mechanism
can
cause
the
automatic
or
semi-
automatic
top
to
be
stuck
in
open,
shut,
or
intermediate
posi-

tion
.
The
following
general
procedures
are
suggested
in
order

to
close
the
top
in
an
emergency
situation
.
Resetting
proce-

dures
for
convertible
top
synchronization
after
emergency
clo-

sure
are
beyond
the
scope
of
this
manual
.

Main
Motor
.
To
release
thetop
linkage
from
the
motor,
lift

the
left
comer
of
the
rearseat
to
access
emergency
release

handle
.
See
Fig
.
17
.

POWER
CONVERTIBLE
TOP

600
Electrical
System-General

GENERAL
.
...........
.
.
.
.
.
.
.
.
.
...
.
...
600-1

Voltage
and
Polarity
........
.
.
.
.
.
.
.
.....
600-1

Ming,
Fuses
and
Relays
............
.
.
.
.
600-1

Electrical
System
Safety
Precautions
...
.
.
.
.
600-1

Electrical
Test
Equipment
.....
.
.
.
....
.
.
.
.
600-2

WIRING
DIAGRAMS
..
.
.
.
.
.
.
.
.
.
........
600-2

Ming
Codes
and
Abbreviations
..
.
...
.
....
600-2

ELECTRICAL
TROUBLESHOOTING
..
.
..
600-3

Voltage
and
Voltage
Drops
..........
.
.
.
.
.
600-4

GENERAL



Electrical
System
Safety
Precautions

A
brief
description
of
the
principal
parts
of
the
electrical
sys-
tem
is
presented
here
.
Also
covered
here
are
basic
electrical
system
troubleshooting
tips
.

Voltage
and
Polarity

The
vehicle
electrical
system
is
a
12-volt
direct
current
(DC)
negative-ground
system
.
A
voltage
regulator
controls
system
voltage
at
approximately
the
12-volt
rating
of
the
battery
.
Al¡
circuits
are
grounded
by
direct
or
indirect
connection
to
the

negative
(-)
terminal
of
the
battery
.
A
number
of
ground
con-

nections
throughout
the
car
connect
the
wiring
harness
to

chassis
ground
.
These
circuits
are
completedby
the
battery

cable
or
ground
strap
between
the
body
and
the
battery
nega-

tive
(-)
terminal
.

Wiring,
Fuses
and
Relays

Nearly
all
parts
of
the
wiring
harnessconnect
to
compo-

nents
of
the
electrical
system
with
keyed,
push-on
connectors

that
lock
into
place
.
Notable
exceptions
arethe
heavy
battery

cables
and
the
starter
wiring
.
The
wiring
is
color-coded
for
cir-

cuitidentification
.

With
theexception
of
the
battery
charging
system,
most

electrical
power
is
routed
from
the
ignition
switch
or
the
bat-
tery
through
the
main
fuse/relay
panel,
located
in
¡he
left
rear

comer
of
the
engine
compartment
.
Fuses
are
color
coded
to

indicate
current
capacities
.

The
relays
and
control
units/modules
are
mounted
in
vari-

ous
places
throughout
the
vehicle
.
See610
Electrical
Com-

ponent
Locations
.

ELECTRICAL
SYSTEM-GENERAL
600-1

Voltage,
measuring
.
.
.
................
.
.
600-4

Voltage
drop,
testing
.
.
.....
.
.....
.
......
600-4

Continuity,
checking
..
.
...
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
600-5
Short
Circuits
.
.
.
.
.
.
.
.
.....
.
...
.
.
.
.
.
.
.
.
.
600-5

Short
circuit,
testing
with
ohmmete'r
.
.
.
.
.
.
.
.
.
600-6

Short
circuit,
testing
with
voitmeter
.
.
.
.
.
.
.
.
.
600-6

TABLES
a
.
Terminal
and
Circuit
Numbers
..............
..
.600-3
Please
read
the
following
warnings
and
cautions
before
do-
ing
any
work
on
your
electrical
system
.

WARNING
-

"
The
cars
covered
by
this
manual
are
equipped
with
aSupplemental
Restraint
System
(SRS)
that
automatically
deploys
one
or
more
airbags
.
Each
airbag
unit
houses
an
explosive
powerful
charge
.
Any
work
involving
the
SRS
system
should
only
be
performed
byan
authorized
BMW
dealer
.
Making
repairs
without
the
proper
knowledge
and
special
test
equipment
may
cause
serious
per-
sonal
injury
.
See
721
Airbag
System
(SRS)
.

"
The
ignition
system
of
the
car
operates
at
lethal
voltages
.
People
with
pacemakers
or
weak
hearts
should
not
expose
themselves
to
the
ignition
sys-
tem
.
Extra
caution
mustbe
taken
when
working
on
the
ignition
system
or
when
servicing
theen-
gine
while
it
is
runningor
the
key
is
on
.
See
120
Ignition
System
for
additional
ignition
system
warnings
and
cautions
.

"
Before
operating
the
starter
without
starting
the
engine
(as
when
making
a
compressfon
test),
dis-
able
the
ignition
system
as
described
in
120
Igni-
tion
System
.

"
Keep
hands,
clothing
and
other
objects
clear
of
the
electric
radiator
coollng
fan
when
working
on
a
warm
engine
.
The
fan
may
start
at
any
tíme,
even
when
the
ignition
is
switched
off
.

GENERAL