check engine BMW M3 1998 E36 Workshop Manual
Page 243 of 759
Symptom
1
Probable
cause
4
.
Vibration,
audible
a
.
Front
centering
guide
worn,
or
a
.
Check
front
centering
guide
and
replace
if
necessary
.
Check
rumble
over35
mph
driveshaft
mounting
flanges
out
of
runout
of
driveshaft
mounting
flanges
.
(60
km/h)
.
round
or
damaged
.
b
.
Mounting
flange
bolts
loose
or
holes
b
.
Remove
driveshaft
and
check
transmissionoutput
flange
and
worn
.
final
drive
input
flange
.
Replace
if
necessary
.
c
.
Driveshaft
unbalanced
.
c
.
Check
driveshaft
for
loose
or
missing
balance
weights
.
Have
driveshaft
rebalanced
or
replace
if
necessary
.
DRIVESHAFT
SERVICE
Driveshaft,
aligning
d
.
Universal
joints
worn
or
seized
.
d
.
Check
universal
joint
play
and
movement
.
Replace
driveshaft
if
necessary
.
e
.
Sliding
coupling
seized
.
e
.
Remove
driveshaft
and
check
movement
of
sliding
coupling
.
1
Clean
coupling
splines
or
replace
parts
asnecessary
.
f
.
Incorrect
preload
of
center
bearing
.
f
.
Check
preload
of
center
bearing
.
Readjust
if
necessary
.
g
.
Center
bearing
faulty
.
g
.
Replace
center
bearing
.
h
.
Final
drive
rubber
mount
faulty
h
.
Inspect
final
drive
rubber
mount
and
replace
if
necessary
.i.
Driveshaft
misaligned
.
i.
Check
driveshaft
alignment
.
Repair
kits
for
the
universal
joints
are
not
available,
and
it
is
not
common
practice
to
repair
the
universal
joints
on
BMW
driveshafts
.
Worn
or
damaged
universal
joints
usually
require
replacement
of
that
section
of
the
driveshaft
.
The
driveshaft
is
balanced
to
cose
tolerances
.
Whenever
it
is
to
be
removed
or
disassembied,
the
mounting
flanges
and
driveshaft
sections
should
bemarked
with
paint
or
a
punch
before
proceeding
with
work
.
This
will
ensure
that
the
drive-
shaft
can
be
reassembled
or
installed
in
exactlythe
same
ori-
entation
.
Universal
joint
play
"
Maximum
allowable
...........
0.15
mm
(0.006
in
.)
The
alignment
of
the
driveshaft
does
not
normally
need
to
be
checked
unless
the
engine/transmission
orthe
final
drive
havebeen
removed
and
installed
.
If,
however,
all
other
parts
of
the
driveshaft
havebeen
inspected
and
found
to
be
okay,
butthere
is
still
noise
or
vibration,
driveshaft
alignment
should
be
checked
.
There
aretwo
important
driveshaft
alignment
checks
.
The
first
is
to
make
sure
that
the
driveshaft
runs
straight
from
the
transmission
to
the
final
drive
;
without
any
variation
from
side-
to-side
caused
by
misalignment
ofthe
engine/transmission
in
its
mounts
.
Make
a
basic
check
by
sighting
along
the
drive-
shaft
from
back
lo
front
.
Any
misalignmentshould
be
apparent
from
the
center
bearingforward
.
To
adjustthe
side-to-side
alignment,
loosen
the
transmission
or
engine
mounts
to
repo-
sition
them,
then
retighten
the
mounts
:
The
driveshaft
should
be
exactly
centered
in
the
driveshaft
tunnel
.
See
Fig
.
2
.
Table
a
.
Driveshaft
Troubleshooting
(continued)
DRIVESHAFT
260-3
Corrective
action
b
:izó
Fig
.
2
.
Driveshaft
side-to-side
alignment
.
Driveshaft
should
be
cen-
tered
in
driveshaft
tunnel
.
The
second
important
driveshaft
alignment
check
is
more
complicated
.
It
checks
the
amount
the
driveshaft
is
angled
vertically
at
the
joints
.
This
angle
is
known
as
driveshaft
de-
flection
.
In
general,
there
should
be
little
deflection
in
the
driveshaft
between
the
engine,
thecenter
bearing,
and
the
final
drive
.
Precise
checks
require
theuse
of
a
large
protractor
or
some
other
means
of
measuring
the
angle
of
the
engine
and
the
fi-
nal
drive
and
comparing
these
angles
to
the
angle
of
the
drive-
shaft
sections
.
To
change
the
deflection
angle,
shims
can
be
placed
between
the
center
bearing
and
the
body
or
between
the
transmission
and
íts
rear
support
.
When
using
shims
to
change
a
deflection
angle,
keep
in
mind
that
the
angle
of
adjacent
joints
will
also
change
.
Deflection
anglesshould
beas
small
as
possible
.
DRIVESHAFTSERVICE
Page 269 of 759
Fig
.
3
.
Power
steering
pump
and
pulley
mounting
bolts
.
6
.
Installation
is
reverse
of
removal,
noting
the
following
:
"
Make
sure
al¡
thread
bores,
bolts,
nuts,
fluid
couplings
and
mating
surfaces
are
clean,
and
that
inside
surface
of
multi-ribbed-belt
is
free
of
grease
and
dirt
.
"
Use
new
sealing
washers
when
reattaching
power
steering
pressure
lines
.
"
Make
sure
hoses
have
adequate
clearance
from
chas-
sis
.
Do
not
over-torque
banjo
bolts
.
"
Fill
and
bleed
power
steering
system
as
described
be-
low
.
Power
steering
system,
bleeding
and
filling
1
.
Wíth
engine
off,
fill
power
steering
fluid
reservoir
with
clean
fluid
.
Fill
levelto
MAX
mark
on
dipstick
.
STEERING
AND
WHEEL
ALIGNMENT
320-
3
STEERING
GEAR
A
cutaway
of
the
power-assisted
rack-and-pinion
power
steering
gear
is
shown
in
Fig
.
4
.
The
rack
is
designed
to
be
maintenance
free
.
Pinion
Fig
.
4
.
Cutaway
of
rack-and-pinion
steering
gear
.
Tightening
Torques
"
Hydraulic
hoses
to
power
steering
pump
?he
steering
gear
and
linkage
require
no
maintenance
oth-
M10
banjo
bolt
.........
..
.
...
...
.
12
Nm
(9
ft-Ib)
er
than
alignment
and
a
periodic
inspection
for
worn
compo
M14
banjo
bolt
..............
..
..
35
Nm
(26
ft-Ib)
nents
.
M16
banjo
bolt
..............
...
.
40
Nm
(30
ft-Ib)
"
Power
steering
pump
to
bracket
Steering
gear
rack,
removing
and
installing
(self-locking
nuts)
.............
..
.
22
Nm
(16
ft-Ib)
"
Power
steering
pump
bracket
to
engine
1
.
Empty
power
steering
fluid
reservoir
using
clean
sy-
block
or
oil
pan
(self-locking
nuts)
...
22
Nm
(16
ft-lb)
ringe
.
Do
not
reuse
fluid
.
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
.
2
.
Start
engine
.
Slowly
turn
steering
wheelfrom
lock
to
lock
a
minimum
of
two
times
.
3
.
Carefully
remove
airbag
from
frontof
steering
wheel
.
See
721
Airbag
System
(SRS)
.
Store
airbag
unit
in
a
sale
3
.
Turn
engine
off
and
check
fluid
leve¡,
adding
fluid
if
nec-
place
.
essary
.
4
.
Make
sure
front
wheelsare
pointed
straight
ahead
.
5
.
Remove
outer
tie
rod
ball
joínt
nuts,
thenseparate
outer
tie
rod
ends
from
steering
arms
using
appropriate
press
tools
.
6
.
Disconnect
power
steering
hose
from
fluid
reservoir
.
STEERING
GEAR
Page 291 of 759
Brake
rotor,
removing
and
installing
.
.
.
.
.
.
.
.
340-7
MASTER
CYLINDER
............
.
.
.
.
.
.
.340-7
Master
cylinder,
removing
and
installing
.
...
.
340-7
GENERAL
TROUBLESHOOTING
WARNING
-
"
Although
semi-metallic
and
metallic
Brake
friction
materials
in
Brake
pads
or
shoes
no
longer
con-
tain
asbestos,
they
produce
dangerous
dust
.
"
Brake
fluid
is
poisonous,
highly
corrosive
and
dangerous
to
the
environment
Wear
safety
glasses
and
rubber
gloves
when
working
with
Brake
fluid
.
Do
not
siphonBrake
fluid
with
your
mouth
.
Immediately
clean
away
any
fluid
spilled
on
painted
surfaces
and
wash
with
water,
asBrake
fluid
will
remove
paint
.
"
Always
use
new
Brake
fluid
froma
fresh,
un-
opened
container
.
Brake
fluid
will
absorb
mois-
ture
from
the
air
.
This
canlead
to
corrosion
problems
in
the
brakingsystem,
and
will
also
low-
er
the
Brake
fluid's
boiling
point
.
Dispose
of
Brake
fluid
properly
.
"
Do
notreuse
self-locking
nuts,bolts
or
fasteners
.
They
are
designed
to
be
used
only
once
and
may
failif
reused
.
Always
replace
them
with
new
self-
locking
fasteners
.
BMW
E36
models
areequipped
with
vacuum
power-assist-
ed
four-wheel
disc
brakes
with
an
integral
Antilock
Brake
Sys-
tem
(ABS)
.
Single-pistoncalipers
act
on
solid
or
vented
front
rotors
and
solid
rear
rotors
.
A
brake
pad
wear
sensor
for
each
axle
indicates
when
brake
padsneed
replacement
.
The
dual
drum-type
parking
brakesystem
is
integrated
with
the
rear
brake
rotors
.
NOTE-
M3
models
havevented
directional
Brake
rotors
on
the
rearaxle
as
well
ason
the
front
.
340
Brakes
BRAKES
340-1
GENERAL
.
.
.
.
.
.
.........
.
.
.
..........
340-1
BRAKE
BOOSTER
.........
.
.
.
.
.
...
.
.
.
.
340-8
TROUBLESHOOTING
.......
.
......
.
...
340-1
Brake
booster,
removing
and
installing
....
.
.
340-8
PARKING
BRAKE
.
.....
.
...
.
.
.
.....
.
.
.
340-10
BLEEDING
BRAKES
.
.
.
.
.
.
.
.
..........
340-3
Parking
brake,adjusting
.
.
.
.
.
.
.
.
.
.
.....
.
340-10
Pressure
bleeding
brakes
Parking
brake
shoes,
removing
and
installing
.
340-11(except
cars
with
AST)
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.340-3
Parking
Brake
cable,
replacing
.
.
.
.
.
.
.
.
.
.
.
.
340-11
BRAKE
PADS,
CALIPERS,
ANTILOCK
BRAKE
SYSTEM
(ABS)
.
.
.
.340-11
AND
ROTORS
..........
.
.......
.
.
.
.
.
.
.
340-3
ABS
System
Inspection
.
...
.
.......
.
.
.
..
340-12
Brake
pads,
replacing
............
.
.
.
.
.
.
.
340-4
ABS
wheel
speed
sensors,
replacing
.
.
.
.
..
340-12
Brake
caliper,
removing
and
installing
.
..
..
.
340-6
TABLES
a
.
Brake
System
Troubleshooting
.....
...
.
.
.....
.340-2
b
.
Brake
Rotor
Reconditioning
Specifications
.
.....
.340-7
Brakeperformance
is
mainly
affected
by
three
things
:
the
leve¡
and
condition
of
the
brake
fluid,
the
system's
abilíty
to
create
and
maintain
hydraulic
pressure,
and
the
condition
of
the
friction
components
.
Air
in
the
Brake
fluid
will
make
the
Brake
pedal
feel
spongy
during
braking
or
will
increase
the
Brake
pedalforce
required
to
stop
.
Fluid
contaminated
by
moisture
or
dirt
can
corrode
the
system
.
Inspect
the
Brake
fluid
inside
the
reservoir
.
Ifit
is
dirty
or
murky,
or
is
over
a
year
old,
the
fluid
should
be
replaced
.
Visually
check
the
hydraulic
system
startingat
the
master
cylinder
.
To
check
the
function
of
the
master
cylinder
hold
the
brake
pedal
down
hard
with
the
engine
running
.
The
pedal
should
feelsolid
and
stay
solid
.
If
the
pedal
slowly
falls
to
the
floor,
either
the
master
cylinder
is
leaking
internally,
or
fluid
is
leaking
externally
.
If
no
leaks
canbe
found,
the
master
cylin-
der
is
faulty
and
should
be
replaced
.
Check
all
Brake
fluid
lines
and
couplings
for
leaks,
kinks,
chafing
and
corrosion
.
Check
the
Brake
booster
by
pumping
the
Brake
pedal
ap-
proximately
10
times
with
the
engine
off
.
Hold
the
pedal
down
and
start
the
engine
.
The
pedal
should
fa¡¡
slightly
.
If
not,
check
for
any
visiblefaults
before
suspecting
a
faulty
brake
booster
.
Check
for
strong
vacuum
at
the
vacuum
hose
fitting
at
the
booster,
and
check
the
non-retum
valve
for
one-way
flow
.
Worn
or
contaminated
brake
pads
will
cause
poor
braking
performance
.
Oil-contaminated
or
glazed
pads
will
cause
stopping
distances
to
increase
.
Inspect
the
rotors
for
glazing,
discoloration
and
scoring
.
Steering
wheel
vibration
while
braking
at
speed
is
often
caused
by
warped
rotors,
but
can
also
be
caused
byworn
suspension
components
.
TROUBLESHOOTING
Page 299 of 759
6
.
Disconnect
ABS
electrical
connectors
.
Label
and
then
disconnect
brake
lines
from
hydraulic
brake
unit
.
Plug
openíngs
.
See
Fig
.
12
.
~
~
A
1/
B
'1v
C
~
F
lu
11
-ri
J
.
0013244
A
.
Right
front
F
Front
from
master
cylinder
B
.
Leftfront
R
.
Rear
from
master
cylinder
C
.
Rear
Fig
.
12
.
Brake
fluid
linesat
ABS
hydraulic
unit
.
WARNING
-
"
On
cars
with
All
Season
Traction
(AST),
special
BMW
service
equipment
is
required
to
properly
bleed
the
Antilock
Brake
System
(ABS)
.
Removal
of
the
ABS
hydraulic
unit
is
not
recommended
un-
less
this
equipment
is
available
.
For
safetyrea-
sons,
the
brake
system
on
cars
with
ABS
must
not
be
bled
using
the
procedures
described
inthis
repair
group
.
"
Do
not
mix
up
the
fluid
fines
at
the
ABS
hydraulic
unit
Label
all
connections
before
disconnecting
.
7
.
Remove
ABS
hydraulic
unit
from
engine
compartment
.
8
.
Working
inside
car,
remove
panel(s)
frombeneath
steering
column
to
access
pedal
assembly
.
See513
In-
terior
Trim
.
12
.
Make
sure
al¡
nuts,
fluid
couplings,
thread
bores
and
mating
surfaces
are
clean
.
BRAKES
340-
9
0011261
Fig
.
13
.
Brake
pedal
clevispin
and
retaining
clip
(A)
.
Brake
booster
mounting
nuts
shown
at
arrows
.
13
.
If
necessary,
mount
master
cylinder
to
vacuum
booster
using
a
new
O-ríng
and
newself-locking
nuts
.
CAUTION-
Do
not
over-torque
the
master
cylinder
mounting
bolts
.
This
could
damage
the
brake
booster
and
prevent
proper
vacuum
build-up
.
14
.
Installation
is
reverse
of
Rmoval
.
"
Bleed
brakes
as
described
earlier
.
"
Check
and,
if
necessary,
adjust
brake
light
switch
above
brake
pedal
.
Tightening
Torques
"
Brakemaster
cylinder
to
brake
booster
...........
.
..
..
...
26
Nm
(18
ft-Ib)
"
Brake
booster
to
bulkhead
.
.
..
..
...
22
Nm
(16
ft-Ib)
"
Brake
fluidline
to
master
cylinder
or
ABS
hydraulic
unit
.......
.
..
17-19
Nm
(13-14
ft-lb)
9
.
Remove
clip
and
clevis
pin
from
brake
booster
pushrod
and
disconnect
it
from
brakepedal
.
Remove
brake
booster
mounting
nuts
.
See
Fig
.
13
.
NOTE-
10
.
Working
in
engine
compartment,
remove
brake
booster
When
replacing
the
brake
booster
one-way
valve
or
together
with
master
cylinder
.
vacuum
hose,
install
the
valve
so
that
the
molded
arrow
is
pointing
toward
the
intake
manifold
.
Use
new
hose
11
.
If
booster
or
master
cylinder
O-ring
is
being
replaced,
clamps
.
disconnect
master
cylinder
from
brake
booster
.
BRAKE
BOOSTER
Page 312 of 759
410-4
FENDERS,
ENGINE
HOOD
4
.
With
aid
of
assistant,
remove
hood
hinge
bolts
from
left
and
Rght
sides
of
hood
.
Lift
hood
off
carefully
See
Fig
.
8
.
Fig
.
8
.
Hood
hinge
bolts
(arrows)
.
Right
side
shown
.
5
.
Installation
is
reverse
of
removal
.
NOTE-
The
hood
was
fitted
and
attached
to
an
unfinished
body
at
the
factory
.
Unfinished
surfaces
exposed
by
this
pro-
cedure
must
betouchedup
wfth
pafnt
.
Hood,
aligning
ENGINE
HOOD
0013149
6013150
Fig
.
9
.
Hood
panel
gaps
should
be
even
(approx
.
5
.5
mm)
at
all
points
(arrows)
.
Hood
release
cable
and
latches,
adjusting
Before
adjusting
hood
latches,
be
sure
the
hood
is
aligned
evenly
to
fenders
and
front
panel
.
The
hood
latch
and
cable
assembly
is
shown
in
Fig
.
10
.
"
Repair
any
paint
damage
and
paint
any
exposed
metal
.
"
Check
hood
alignment
as
described
next
.
1
.
To
adjust
hood
cables
:
When
installing
the
hood,
align
the
hinges
as
close
to
the
original
paintedsurface
as
possible
.
Movement
of
the
hood
on
its'attaching
hardware
may
require
touch-up
paint
.
The
hood
should
be
aligned
so
that
gapson
all
sides
areas
even
as
possible
.
See
Fig
.
9
.
Clearance
Specification
"
Hood
edges
to
adjoining
body
panel
(gap)
........
..
..
..
.....
.5
.5
mm
(0.216
in)
"
Remove
left
and
right
radiator
grilles
.
See
510
Exterior
Trim,
Bumpers
.
"
Remove
electric
auxíliary
cooling
fan
.
See
170
Radia-
tor
and
Cooling
System
.
"
Adjust
cable
section
between
two
hood
latches
so
there
is
no
play
(cables
must
not
be
under
tension
ei-
ther)
.
2
.
Loosen
hood
latches
at
hood
on
left
and
right
sides
.
Loosen
bolts
only
enough
to
allow
movement
of
latch
.
See
Fig
.
11
.
3
.
Lower
(but
do
not
fully
latch)
hood
severa¡
times
so
latches
on
hood
center
themselves
in
lower
locks
.
CA
UTION-
Do
not
let
hood
fockwith
latchbolts
loose
.
4
.
Tighten
hood
latch
bolts
when
alignment
is
correct
.
5
.
Remove
one
screw
fromeach
side,
clean
and
coat
with
Loctite
O
270
or
equivalent,
and
reinstall
.
Page 381 of 759
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
Page 382 of 759
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
.
Page 384 of 759
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
.
Page 385 of 759
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
Page 397 of 759
Table
a
.
E36
Component
Locations
Component
Model
Year
Location
Refer
to
Anti-theft
Control
Module
1992-1998
Behind
glove
compartment
Fig
.
8
.
Fig
.
9
.
Anti-theft
Horn
1
1992-1998
1
Right
rear
engine
compartment
Anti-slip
(Traction)
Control
Module
1994-1998
Power
distribution
box
Fig
.
8
.
(AST/ASC+T)
Fig
.
9
.
Anti-slip
(Traction)
Control
Switch
1994-1998
In
center
console
Automatic
Climate
(A/C)
Control
1992-1998
Behind
center
console
Module
AutomaticTransmission
Range
1992-1998
~
Next
to
gear
shift
lever
in
center
console
Fig
.
29
.
Switch
(Gear
Position/Neutral
Safety
Switch)
Auxiliary
Cooling
Fan
Dual
Switch
1992-1998
Right
side
radiator
1
Fig
.
18
.
Auxiliary
Cooling
Fan
Motor
1992-1998
Behind
front
grill
Auxiliary
Fuse
Box
(Left
Splice
1992-1998
I
Behind
left
front
footwell
kick-panel
Panel)
Auxiliary
RelayPanel
1
1992-1998
1
Left
side
of
dash
under
steering
column
Auxiliary
Fuse
Box
In
Trunk
1
1997-1998
1
Right
sideof
trunk
behind
trim
panel
AuADSry
ThrottlePosition
Motor
11994-1998
Front
of
engine
compartment
B+
Jump
Start
Junction
Point
1992-1998
Right
rear
of
engine
compartment
Fig
.
7
.
Back-Up
Light
Switch
(Manual)
1992-1998
Right
or
left
side
top
of
transmission
Fig
.
30
.
Body
Electronics
Control
Module
1994-1998
Behindglove
compartment
Fig
.
8
.
(ZKE
IV)
Fig
.
9
.
Brake
Fluid
Level
Sensor
1992-1998
Top
of
brake
fluid
reservoir
at
master
cylinder
Fig
.
15
.
Brake
Light
Switch
1
1992-1998
1
On
brake
pedal
supportbracket
Brake
Pad
Sensor,
Left
Front
1
1992-1998
1
Left
front
brake
caliper
Brake
Pad
Sensor,
Right
Rear
1992-1998
Right
rear
brake
caliper
Camshaft
Actuator
(VANOS)
1993-1998
Front
of
cylinder
head
Camshaft
Position
Sensor
(Cylinder
1992-1998
Front
of
engine
Identification)
Carbon
Canister
Valve
(TLEV)
1
1997-1998
1
In
sparewheel
well
in
trunk
ELECTRICAL
COMPONENT
LOCATIONS
610-11
Fig
.
5
.
Fig
.
4
.
Fig
.
24
.
Fig
.
7
.
Central
Locking
Module
(ZVM)
11992-1993
1
Behindglove
compartment
I
Fig
.
8
.
Fig
.
9
.
Check
Control
Module
(if
applicable)
1
1992
-
1998
1
Below
left
side
of
dash
Child
Protection
Window
Control
1992-1998
Center
console
(console)
Chime
Module
1992-1998
Below
left
side
of
dash
inleft
dash
trim
panel
Clock
(Multi-Function)
1993-1998
Center
console
Clutch
Pedal
Switch
1992-1998
On
clutch
pedal
support
bracket
Continued
COMPONENT
LOCATIONS