Oxygen
Sensor
FUEL
DELIVERY
TESTS
FUEL
INJECTION
130-
9
"
Voltage
at
¡dle
..
.
..
..
....
0
.2
to
0
.8
VDC,
fluctuating
Checking
fuel
delivery
is
afundamental
part
of
trouble-
shooting
and
diagnosing
the
engine
management
system
.
Fuel
pressure
directly
influences
fuel
delivery
.
An
accurate
NOTE-
fuel
pressure
gauge
will
be
needed
to
make
the
tests
.
To
check
sensorresponse
to
lean
and
rich
mixtures,
createenairleak,
orpull
vacuumhoseofffue¡
pressure
There
are
three
significant
fuel
delivery
values
to
be
mea-
regulator
to
increase
fuel
pressure
.
sured
:
3
.
Separate
sensorharness
connector
from
sensor
.
Check
for
battery
voltage
between
terminals
3
and
4
(green
wire
and
brown
wire)
in
main
wiring
harness
side
of
con-
nector
with
engine
running
.
If
voltage
is
not
present,
check
oxygen
sensor
heater
relay
.
See610
Electrical
Component
Locations
.
4
.
Check
heater
element
resistance
between
terminals
3
and
4
in
sensor
side
of
connector
.
If
element
is
electri-
cally
open
(no
continuity),
replace
sensor
.
NOTE-
The
oxygen
sensor
heater
relay
is
mounted
in
the
main
power
distributfon
box
in
the
left
rear
of
the
engine
com-
partment
.
Refer
to
Fig
.
6
.
The
heater
relay
is
energized
wíth
positive
(+)
battery
voltage
from
the
main
relayanda
switched
ground
from
the
ECM
.
See
Electrical
Wir-
ing
Diagrams
.
"
Oxygen
sensor
to
exhaust
pipe
...
..
55
Nm
(41
ft-Ib)
"
System
pressure-created
by
the
fuel
pump
and
main-
tained
by
the
pressure
regulator
.
"
Fuel
delivery
volume-created
by
the
fuel
pump
and
af-
fected
by
restrictions,
suchasclogged
fuel
filter
.
"
Residual
pressure-the
pressure
maintained
in
the
closed
system
after
the
engine
and
fuel
pump
are
shut
off
.
Procedures
for
measuring
the
first
two
quantities
arede-
scribed
in
160
Fuel
Tank
and
Fuel
Pump
.
Residual
fuel
pres-
sure
is
checked
using
the
procedure
detailed
later
in
this
group
.
Operating
fuel
pump
fortests
To
operate
the
fuel
pump
for
testing
purposes
without
hav-
íng
to
runthe
engine,
the
fuel
pump
relay
can
be
bypassed
to
power
the
pump
directly
.
Fuel
pump
relay
location
is
shown
in
Fig
.
6
.
5
.
¡f
oxygen
sensor
doesn't
produce
a
fluctuating
voltage
To
runthe
fuel
pump,
remove
the
fuel
pump
relay
and
con-
and
preheater
circuit
is
OK,
replace
sensor
.
nect
the
socket
for
relayterminal
30
to
the
socket
for
relay
ter-
mina¡
87
with
a
fused
jumper
wire
.
After
completing
the
tests,
NOTE-
remove
the
jumper
wire
.
If
not
already
applied,
coat
the
oxygen
sensor
threads
with
an
anti-seize
compound
before
installation
.
Do
not
CAUTION-
getthe
compound
on
the
sensor
tip
.
"
Relay
locations
may
vary
.
Use
care
when
identi-
fying
relays
and
making
electrical
checks
at
the
fuselrelay
panel
.
See
610
Electrical
Compo
Tightening
Torque
nent
Locations
for
additional
relay
information
.
"
The
fuel
pump
relay
has
a
1
.5
mm2
red
wire
at
ter-
minal
30
in
the
relay
socket
.
Terminal
87
has
a
1
.5
mm
2
greenlviolet
wire
.
See
Electrical
Wiring
Di-
agrams
for
additional
wiring
information
.
NOTE-
Thejumper
wire
should
be
1.5
mm2
(14
ga
.)
and
in-
clude
an
in-line
tuse
holder
with
a15
amp
tuse
.
To
avoid
fuselrelay
panel
damage
from
repeated
connect-
ing
and
disconnecting,
also
include
a
toggle
switch
.
A
heavy-duty
jumper,
BMW
tool
no
.
61
3
050,
is
also
available
from
an
authorized
BMW
dealer
.
FUEL
DELIVERYTESTS
160-
6
FUEL
TANK
AND
FUEL
PUMP
Fig
.
7
.
Fuel
sender
and
pump
assembly
.
To
operate
the
fuel
pump
for
testing
purposes
without
hav-
Fuel
leve¡
sender
(left
side),
ing
to
runthe
engine,
the
fuel
pump
relay
can
be
bypassed
to
removing
and
installing
powerthe
pump
directly
.
The
procedure
for
removing
and
replacing
the
left
side
fuel
To
runthe
fuel
pump,
remove
the
relay
and
connect
the
leve¡
sender
is
similar
tothat
used
for
the
right
side
.
There
is
socket
for
relayterminal
30
to
the
socket
for
relay
terminal
no
.
no
fuel
pump
on
the
left
side
.
87
with
afused
jumper
wire
.
Relay
terminal
identification
is
shown
in
Fig
.
9
.
After
completing
the
tests,
remove
the
jumper
wire
.
FUEL
PUMP
The
electric
fuel
pump
ís
mounted
in
the
fuel
tank
in
tandem
with
the
right
side
fuelleve¡
sender
.
The
fuel
pump
delivers
fuel
at
high
pressure
to
the
fuel
injection
system
.
A
pressure
regulator
maintains
system
pressure
.
The
quantity
of
fuel
sup-
plied
exceeds
demand,
so
excess
fuel
retums
to
the
fuel
tank
via
a
retum
líne
.
See
130
Fuel
Injection
for
more
information
on
system
pressure
and
the
fuel
pressure
regulator
.
NOTE
-
Fuel
pump
removalprocedures
are
given
earlier
under
Fuel
leve¡
sender
(right
side)
and
fuel
pump,
remov-
íng
and
installing
.
Fuel
Pump
Fuse
and
Relay
The
fuel
pump
is
operated
by
a
fuel
pump
relay
located
ín
the
power
distribution
box
.
The
fuel
pump
circuit
is
protected
by
fuse
no
.
18
located
in
the
power
distribution
box
.
See
Fig
8
.
FUEL
PUMP
0013142
Fuel
DM
E
PUMP
main
re
ay
rel
ay
0
aoo
o
~a
aao
ó
Fig
.
8
.
Fuel
pump
relay
location
in
power
distribution
box
.
The
DME
engine
control
module
(ECM)
and
the
DME
main
relay
supply
power
to
the
coi¡
sideof
the
fuel
pump
relay
.
Dur-
ing
starting,
the
fuel
pump
runs
as
long
as
the
ignition
switch
is
in
the
start
position
and
continues
to
run
oncethe
engine
starts
.
If
an
electrical
system
fault
interrupts
power
to
the
fuel
pump,
the
engine
will
notrun
.
Operating
fuel
pump
for
tests
CA
UTION-
Relay
locations
may
vary
.
Use
care
when
identify-
ing
relays
and
when
troubleshooting
the
electrical
system
at
the
fuselrelay
panel
.
The
fuel
pump
re-
¡ay
is
a
four
pin
relay
and
has
a
1.5
mm
2
red
wireat
terminal
30
in
the
relay
socket,
lf
in
doubt,
con-
sult
an
authorized
BMW
dealer
.
NOTE-
Thejumper
wire
shouldbe
1.5
mm2
(14
ga
.)
and
in-
clude
en
in-fine
fuse
holder
with
a16
amp
fuse
.
To
avoid
fuselrelay
panel
damage
fromrepeated
connect-
íng
and
disconnecting,
also
include
a
toggleswitch
.
A
heavy-duty
jumper,
BMW
tool
no
.
613
050,
fs
also
available
from
en
authorized
BMW
dealer
.
0013034,
If
the
pump
does
notrun
with
the
jumper
installed,
the
fault
could
be
in
the
fuel
pump
or
the
wiring
to
the
pump
.
Check
the
pump
and
its
wiring
as
described
below
.
Fig
.
9
.
Fuel
pump
relay
terminal
identification
.
Fuel
Pump
Electrical
Tests
Troubleshooting
of
any
fuel
pump
fault
should
begin
with
checking
the
fuel
pump
fuse
and
the
fuel
pump
relay
.
The
DME
main
relay
should
also
be
checked
.
NOTE-
Special
tools
are
requíred
for
some
of
the
tests
de-
scribed
here
.
Fuel
pump
electrical
circuit,
testing
The
fuel
pump
electrical
circuit
diagram
is
shown
in
Fig
.
10
.
3
.
If
fuel
pump
does
not
run,
disconnect
black
harness
connector
from
tank
sender
unit
.
With
jumper
wire
con-
nectedas
described
in
step
2
above,
check
for
positive
(+)
batteryvoltage
at
harness
connector
terminals
.
See
Fig
.
11
.
FUEL
TANK
AND
FUEL
PUMP
160-
7
From
Main
Relay
(+15
power
with
key
in
run
From
B+juretion
point
orstartposition)
(batteryvoRageatalltirnes)
'
.5
RD/Nrr
1
.5
RD
1
.5
GNNI
From
Engine
2
.5
GNNI
Control
Module
15
2
.5
GNNI
Ground
(below
center
console)
Fig
.
10
.
Fuel
pump
electrical
circuit
.
30
-~
Relay
Fuel
Pump
8~T
I
1
s
ám
61
Front
Power
I
a
1
Distribution
Box
I_
16
WIRING
COLOR
CODE
BK
-
BLACK
BR
-
BROWN
Fuel
Pump
RD
-
RED
(in-tank)
M
YL
YELLOWGN
-
GREENBU
-
BLUE
1
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK
0011946
4
.
If
voltage
and
groundare
present,
fuel
pump
is
proba-
bly
faulty
.
If
there
is
no
voltage,
check
wiring
From
fuel
pump
Reay
and
make
sure
Reay
is
functioning
correctly
.
CAUTION-
Fuseandrelaylocationsmayvary
.
Usecara
when
Fuel
pump
power
consumption,
testing
troubleshooting
the
electrical
system
at
the
fuselrelay
panel
.
To
resolve
problems
in
identify-
NOTE-
ing
a
relay,
see
en
authorízed
BMW
dealer
.
"
To
achieveaccurate
testresults,
fhe
battery
voltage
at
the
connector
should
be
approximately
13
volts
.
1.
Remove
rearseat
cushion,
pull
right
side
insulation
mat
Charge
the
battery
asnecessary
.
back
to
expose
fuel
tank
accesscover
.
Remove
cover
.
q
higher
than
normal
power
consumption
usually
fin-
to
expose
wiring
connections
.
dicates
a
worn
fuel
pump,
which
may
cause
intermit-
tentfuel
starvation
due
lo
pump
overheating
and
2
.
Remove
fuel
pump
relay
and
opérate
fuel
pump
as
de-
seizure
.
The
only
remedy
is
pump
replacement
.
Be
scribed
under
Operating
fuel
pump
for
tests
earlier
.
sure
to
check
that
thereturn
fine
and
the
pump
pickup
Pump
should
run
.
Disconnect
jumper
wire
when
fin-
are
not
obstructed
before
replacing
the
pump
.
ished
.
1
.
Remove
rear
seat
cushion,
pull
right
side
insulation
mal
back
to
expose
fuel
tank
accesscover
.
Remove
cover
to
expose
wiring
connections
.
2
.
Disconnect
(black)
harness
connector
from
fuel
pump
.
3
.
Connect
an
ammeter
and
an
insulated
jumper
wire
be-
tween
terminals
in
connector
and
corresponding
pump
terminals
.
See
Fig
.
12
.
FUEL
PUMP
NOTE-
Some
cars
covered
by
this
manual
may
have
an
alter-
nate
cooling
fan
switchwith
switching
temperatures
of
176%190W
(80%88°C)
.
When
replacing
the
switch
check
theswitching
specifications,
whichshouldbe
stamped
on
the
switch
body
.
1
.
If
coolant
is
circulating
at
normal
operating
tempera-
ture,
but
auxiliary
cooling
fan
does
not
run,
disconnect
connector
from
radiator
temperature
switch
and
make
tests
listed
in
Table
c
.
Table
c
.
Auxiliary
Cooling
Fan
Temperature
Switch
Tests
Wires
jumpered
Test
Test
resuits
conditions
Black/green
(terminal2)
and
Ignition
ON
Fan
runs
on
brown
(terminal
1)
low
speed
Black/gray
(terminal
3)
and
Ignition
ON
Fan
runson
brown
(terminal
I
1)
high
speed
2
.
If
fan
runs
only
when
powered
directly
by
jumpered
connector
and
hot
coolant
is
circulating
through
radia-
tor,
radiator
temperature
switch
is
most
likelyfaulty
.
Use
a
new
sealing
ring
when
replacing
switch
Tightening
Torque
"
Temperature
switch
to
radiator
......
15
Nm
(11
ft-Ib)
3
.
If
auxiliary
fan
does
notrun
when
powered
directly,
check
for
battery
voltage
at
temperature
switch
connec-
tor
(black/green
wire)
with
ignition
on
.
If
battery
voltage
is
not
present,
check
fuses
.
See
610
Electrical
Com-
ponent
Locations
.
RADIATOR
AND
COOLING
SYSTEM
170-
5
~r~nmm
a
00
0
Fig
.
4
.
Auxiliary
radiator
cooling
fan
low
speed
relay
(1)
and
high
speed
relay
(2)
in
power
distribution
box
.
(Relay
locations
may
vary
.)
Auxiliary
Cooling
Fan
Circuit
Fuses
Fig
.
5
.
Auxiliary
radiator
fan
resistor
(arrow)
.
"
Fuse16
.
...................
..
..
...
...
.5
amp
"
Fuse
41
(ex
.
M44
w/man
.
trans)
.
..
.
..
.....
30
amp
"
Fuse
48
(M44
w/man
.
trans
.
only)
..
.
..
.....
40
amp
COOLING
SYSTEM
SERVICE
0013034
4
.
If
no
faults
are
found,
remove
low
speed
relay
and
turn
Coolant,draining
and
filling
ignition
ON
.
See
Fig
.
4
.
1
.
Remove
expansion
tank
cap
.
Set
temperature
controls
"
Check
for
power
at
terminal
30
and
terminal
86
of
relay
to
full
warm
.
socket
.
"
Reinstall
low
speed
relay
and
repeat
testat
high
speed
WARNING
-
relay
socket
.
Fix
any
wiring
faults
found
.
Allow
the
cooling
system
to
cool
before
openlng
or
On
early
productioncars
(up
to
9/92)
:
If
fan
operates
only
on
draining
the
cooling
system
.
high
speed
and
no
electrical
faults
have
been
foundup
to
this
point,
usean
ohmmeter
to
check
that
fan
resistor
is
not
electri-
2
.
Place
3
ra
allo
ug
.
beneath
radiator
drain
plug
and
re-
cally
open
.
Resistor
is
mounted
on
auxiliary
cooling
fan
housing
move
drain
plg
.
See
Fig
.
6
.
behind
front
grille
.
See
Fig
.
5
.
Wiring
diagrams
for
the
radiator
cooling
fan
canbefoundunder
Electrical
Wiring
Diagrams
.
3
.
Place
3-g
pail
beneath
rear
of
engine
blo
.
Loos-
en
and
re
mlon
ove
engine
blockcoolant
drain
plug
k
.
COOLING
SYSTEM
SERVICE
ENGINE
HOOD
Hood,
raising
to
service
position
CA
UTION-
Do
not
switch
on
the
windshield
wipers
wlth
the
engine
hood
raised
.
As
a
precaution,
remove
the
wiper
motor
fuse
.
See
610
Electrical
Compo-
nent
Locations
.
1
.
4-door
models
:
Open
hood
fully
.
Remove
bolt
from
hood
hinge
behind
hood
supports
(left
and
right)
.
Raise
hood
to
service
position
.
See
Fig
.
5
.
2
.
2-door
models
:
Open
hood
fully
.
Fig
.
5
.
Hood
support
bracket
boltto
be
removed
(A)
on
4-door
cars
.
Remove
bolts
at
left
and
right
hinges
.
Swing
bracket
in
direc-
tion
of
arrow
to
raise
hood
into
service
position
.
"
Remove
ground
cable
atright
hood
hinge
.
"
Whilean
assistant
supports
hood,
detach
both
hood
supportsfrom
hood
.
"
Remove
detent
screws
at
back
of
hood
hinges
.
See
Fig
.
6
.
"
Lift
hood
while
pulling
hinge
forward
.
Support
hood
at
higher
position
.
3
.
When
service
work
is
complete,
return
hood
to
lower
position
and
instaf
screws
or
bolts
.
FENDERS,
ENGINE
HOOD
410-
3
Fig
.
6
.
Torx
screw
at
base
of
hood
hinge
(arrow)
.
Hood,
removing
and
installing
0013147
1
.
Raise
hood
.
Where
applicable,
partially
remove
hood
acoustic
insulation
to
access
rear
of
hood
.
See
Fig
.
7
.
Fig
.
7
.
Hood
insulation
retainer
being
pried
out
3
.
Detachgas-charged
hood
supportsfrom
hood
.
CAUTION
-
The
hood
is
heavy
.
Before
removing
the
hood
sup-
ports
or
hood
retainingbolts,
be
sure
to
have
an
assistant
help
support
the
hood
.
0013148
2
.
Disconnect
washer
fluid
hoses
from
washer
nozzles
.
Where
applicable,
disconnect
electrical
harness
con-
nectors
fromheated
nozzles
.
ENGINE
HOOD
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
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
.
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