1992 BMW M3 sensor

When
bleeding
the
brakes,
startat
the
wheel
farthest
from



4
.
Close
bleeder
screw
and
release
brake
pedal
.
Refill
the
master
cylinder
and
progress
in
the
following
order
:



brake
fluid
reservoir
and
proceed
to
rear
left
wheel
.

"
right
rear
brake



5
.
Proceed
with
the
remaining
wheels
using
the
order
list-

"
left
rear
brake



ed
earlier
.

"
rightfront
brake

"
left
front
brake

Pressure
bleeding
brakes

(except
carswith
AST)

1
.
Top
off
brake
fluid
in
reservoir
and
connect
pressure

bleeder
to
reservoir
.
Connect
bleeder
hose
and
bottle
to
right
rearcaliper
bleeder
screw
.
Pressurize
system

to
approximately
1
bar
(14
.5
psi)
.

BRAKES
340-
3

Tightening
Torques

"
Bleeder
screws
:

7
mm
screw
..........
..
.
.
.
.
......
5
Nm
(4
ft-Ib)

9
mm
screw
..........
..
.
..
.......
6
Nm
(5
ft-Ib)

BRAKE
PADS,
CALIPERS,
AND
ROTORS

CAUTION-



TheE36
front
brake
caliper
is
shown
in
Fig
.
2
.
The
rear

Do
not
exceed
a
pressure
of
2
bar
(29
psi)
when



brake
caliper
is
shown
in
Fig
.
7
.

pressure
bleeding
the
brake
system
.
Excessive
pressure
will
damage
the
brake
fluid
reservoir
.



Brake
pads
canbe
replaced
without
disconnecting
the
brake
fluid
hose
from
the
caliper
or
having
to
bleed
the
brakes
.

2
.
Have
a
helperhold
brake
pedal
down
.



The
rotors
can
be
replaced
without
disassembling
the
wheel
huband
bearing
.
Always
machine
or
replace
rotors
in
parts
.

3
.
Open
bleeder
screw
.
See
Fig
1
.
Have
helper
slowly
,



Replace
pads
in
sets
.

pump
brakes
about10
times
with
bleeder
screw
open,

holding
pedal
down
on
the
last
pump
.
When
escaping



WARNING-

fluid
is
free
of
air
bubbles,
close
bleeder
screw
.



"
Althoughsemi-metallicandmetallicbrake
friction
materials
in
brake
pads
or
shoes
no
longer
con

CAUTION-



tain
asbestos,
they
produce
dangerous
dust
.

Bleeder
hose
must
alwaysremain
submersed
in



"
Treat
all
brake
dust
asa
hazardous
material
.
the
clean
brake
fluid
whenever
the
bleeder
valve
is
open
.



"
Do
not
create
dust
by
grinding,
sanding,
orclean-
ing
brake
friction
surfaces
with
compressed
air
.

"
Breathing
any
brake
dust
can
cause
serious
dis-
eases
such
as
cancer,
and
may
result
in
death
.

Brake
pads,
replacing

This
procedure
is
applicable
lo
both
front
and
rear
brakes
.

Front
and
rear
brake
assemblies
are
basically
the
same,
ex-

cept
that
the
rear
brake
rotors
house
the
parking
brake
mech-

anism

1
.
Raise
car
andremove
wheels
.

WARNING
-

Make
sure
thecar
is
firmly
supported
onjack
stands
designed
for
the
purpose
.
Place
the
jack
stands
be-
neath
a
structural
chassis
point
.
Do
not
place
jack
stands
undersuspension
parts
.

2
.
Remove
plastic
caps
from
guide
bolts
and
then
remove

guide
bolts
.
See
Fig
.
3
.

0012113



3
.
If
applicable,
disconnect
brake
pad
wear
sensor
con-
Fig
.
1
.



Brake
caliper
bleeder
screw
(arrow)
.



nector
and
remove
wiring
from
its
holder
.

4
.
Remove
anti-rattle
clip
from
caliper
.
See
Fig
.
4
.

BRAKE
PADS,
CALIPERS,
AND
ROTORS

340-
4
BRAKES

Fig
.
2
.



Front
brake
caliper
assembly
.

Bleeder
valve
and
dust
cap

Mounting
bolt

Brake
pad
wearsensor
(left
wheel
only)

-
Brake
pad
.
carrier
Anti-rattle
^_
spring-

0012154

Fig
.
3
.



Brake
caliper
guide
bolts
(arrows)
.

5
.
Pull
caliper
straight
off
rotor
.

CAUTION-

Do
not
let
the
brake
cafiper
hang
from
the
brake
hose
.
Suspend
ft
from
the
chassis
using
stiff
wire
.

BRAKE
PADS,
CALIPERS,
AND
ROTORS

0012155

Fig
.
4
.



Removing
anti-rattle
clip
by
unhooking
at
top
and
bottom
.
Use
screwdriver
asan
aid
(arrow)
.

NOTE-

If
there
is
a
ridge
on
the
rotor
edge,
the
cafiper
pfston
will
have
to
be
pushed
back
finto
the
cafiper
before
the
cafiper
can
be
removed
.

6
.
Remove
brake
pads
from
caliper
.
Where
applicable,
carefully
pry
pad
wear
sensor
from
pad
.
See
Fig
.
5
.

Fig
.
5
.



Removing
brake
pad
wear
sensor
.

7
.
Inspect
brake
caliper
for
signs
of
leakage
.
Check
that
the
caliper
piston
slides
smoothly
into
caliper
.
Replace
caliper
if
any
faults
are
found
.

CAUTION-

With
the
pads
removed,
residual
hydreulic
pres-
sure
may
cause
the
caliper
piston
to
slide
out
.
Use
a
wooden
block
to
hold
the
piston
in
place
.

8
.
fnsert
brake
pad
wear
sensor
into
cutout
in
new
pad

where
applicable
.

14
.
Place
inner
brake
pad
(with
locating
spring)
ontobrake
NOTE-



caliper
piston
.
Route
pad
wear
sensor
wiring
through
lf
the
brake
lining
indicator
light
illuminated
prior
to



caliper
opening
and
bleeder
dust
cap
.
brake
pad
replacement,
the
wear
sensor
should
be
re-
placed
.



15
.
The
remainder
of
installation
is
reverse
of
removal
.

"
Do
not
lubricate
guide
boits
.
9
.
Slowly
press
piston
back
into
caliper
.
Use
cace
not
to



"
Once
brake
assembly
is
installed
depress
brakepedal
damage
piston
dust
sea¡
.
See
Fig
.
6
.



severa¡
times
before
driving
vehicle
.

NOTE-

"
Open
caliper
bleeder
screw
when
pressing
piston



Tightening
Torques

back
into
caliper
.
Catch
expelled
fluidin
appropriate



"
Brake
caliper
to
brake
pad

container
.
This
procedure
is
highly
recommended
in



carrier
(guide
bolt)
..........
...
.
.
30
Nm
(22
ft-Ib)

the
case
of
cars
with
ABS
.



"
Road
wheel
to
hub



.....
.
..
100±10
Nm
(74±7
ft-Ib)

"
Open
the
bleeder
screw
only
when
applying
force
to
the
piston
.
Do
not
allow
airto
be
drawn
in
through
the
bleeder
screw
.

"
Pressing
the
caliper
piston
in
may
cause
the
brake
flu-
id
reservoir
to
overflow
.
To
prevent
this,
use
a
clean
syringe
to
first
remove
some
fluid
from
the
reservoir
.

BRAKES
340-
5

0012157
Fig
.
6
.



Brake
caliper
piston
being
pressed
into
caliper
to
make
room
for
new
pads
.
Usea
rag
toprotect
caliper
piston
and
seals
.

10
.
Thoroughly
clean
inner
and
outer
surfaces
of
brake
ro-
tor
.
Inspect
rotor
for
cracks,
signs
of
overheating
and
0012156
scoring
.

11
.
Measure
thickness
of
rotor
.
See
Table
b
.
If
rotor
does
not
pass
minimum
thickness
requirements,
or
is
dam-

aged,
replace
as
described
later
.

12
.
Thoroughly
clean
all
contact
points
on
caliper
and
brake
pad
carrier
.
Clean
guide
bolts
and
make
surethey
slide
freely

13
.
Lightly
coat
pad
contact
points
with
brake
anti-squeal
paste
.
Place
outer
brake
pad
onto
caliper
.
Applya
small
amount
of
grease
to
thetop
and
bottom
contact
points
where
the
caliper
contacts
the
pad
carrier
.

BRAKE
PADS,CALIPERS,
ANDROTORS

340-
6BRAKES

bolt~



Guide
bolt

caps
covers
Brake
caliper
Shoe
retaining
píns

Parking
brake
cable

Fig
.
7
.



Rear
brake
caliper
assembly
.

Caliper
guide



Brake



ad
bolts
,



Bleeder
valve



i
_
~wear
sénsor
®



and
dust
cap



(right
wheel
V
.
.,,,

Brake
caliper,
removing
and
installing

1
.
Raise
car
and
remove
wheel
.

WARNING
-

Make
sure
the
car
is
firmly
supported
on
jack
standsdesigned
for
the
purpose
.

2
.
Loosen
brake
hose
fitting
at
caliper
.
Do
not
remove
.

3
.
Remove
caliper
mounting
bolts
from
steering
arm
(Font

caliper)or
from
trailing
arm
(rear
caliper)
.
See
Fig
.
8
.

4
.
Press
piston
back
into
caliper
and
slide
caliper
off
brake

rotor
.
Spin
caliper
off
brake
hose
.

5
.
Inspect
brake
caliper
for
signs
of
leakage
.
Check
that
caliper
piston
slides
smoothly
into
caliper
.
Replace
cal-

iper
if
any
faults
are
found
.

6
.
Installation
is
reverse
of
removal
.
Bleed
entire
brake

system
before
driving
car
.
See
Bleeding
Brakes
.

Tightening
Torques

"
Front
brake
caliper
to
steering
arm
..
110
Nm
(81
ft-Ib)

"
Rear
brake
caliper
to
trailing
arm
....
67
Nm
(50
ft-Ib)

"
Brake
fluid
hose
to
caliper
....
17-19
Nm
(13-14
ft-Ib)

"
Road
wheel
to
hub



........
100±10
Nm
(74±7
ft-Ib)

BRAKE
PADS,CALIPERS,
ANDROTÓRS

Cover

Caliper



!



Brake
pad
Oringiston



carne
-
p

Circli

©
ot~
AV
~:
Z



1vo~
Spring
and
spring
retainer



uust
seas



~~



Aniráttle

j),
Brake



spring
Shoe
pads
_
_

adjuster



per
return

nf

MIL

Rotor
with
integrated
parking
brake
drum
6573

0011256

Fig
.
8
.



Front
brake
pad
carrier
mounting
bolts
(arrows)
.
Rear
caliper
mounting
bolts
are
similar
.

340-
1
2
BRAKES

ABS
is
self-tested
by
the
ABS
diagnostic
unit
each
time
the
car
is
started
.
Once
the
test
is
complete,
the
ABS
dashboard
light
tucos
off
.
If
the
light
remains
lit
or
comes
on
at
any
time
during
driving,
a
system
fault
has
occurred
and
ABS
is
elec-
tronically
disabled
.
The
conventional
braking
systemremains
fully
functioning
.

ABS
Inspection

A
visual
inspection
of
the
ABS
may
help
to
locate
system
faults
.
If
no
visual
faults
can
befound
and
the
ABS
light
re-
mains
on,
have
the
system
diagnosedbyan
authorized
BMW
dealer
.

Carefully
inspect
the
entire
ABS
wiring
harness,
particularly

the
pulse
sensorharnesses
and
connectors
near
each
wheel
.

Look
for
chafing
or
damage
due
to
incorrectly
routed
wires
.

Carefully
remove
the
wheelspeed
sensors
.
Clean
the
sen-



Fig
.
18
.
Front
ABS
pulse
sensor
mounting
bolt
(arrow)
.
sor
tips
.
Inspect
the
toothed
wheel
on
thewheel
hub
.
Check
for
missing,
clogged
or
corroded
teeth,
or
other
damage
that
could
alter
the
clearance
between
the
sensor
tip
and
the
toothed
wheel
.

NOTE-

If
a
toothed
ring
is
damaged,
the
entire
wheel
hub
mustbe
reptaced
.
See
310
Front
Suspension
or330
Rear
Suspension
.

ABS
wheel
speed
sensors,
replacing

1
.
Raise
applicable
end
of
car
.

WARNING
-

Make
sure
thecar
is
firmly
supportedon
jack
stands
designed
for
the
purpose
.
Place
the
jack
stands
be-
neath
a
structural
chassis
point
Do
not
place
jack
stands
under
suspension
parts
.

2
.
Unscrew
wheelspeed
sensor
mounting
bolt
.
Remove
sensor
from
its
housing
.
See
Fig
.
18
.
Remove
harnessfrom
retaining
mounts
.

3
.
Front
ABS
sensor
:
Working
in
front
wheel
housing,
dis-
connect
and
remove
sensor
.
See
Fig
.
19
.

4
.
Rear
ABS
sensor
:
Working
in
rear
wheel
housing,
dis-
connect
andremove
sensor
.

5
.
During
installation,
apply
thin
coat
of
Molykote
0
Long-
term
2
or
an
equivalent
grease
to
pulse
sensor
and
housing
.

ANTILOCK
BRAKE
SYSTEM
(ABS)

0012122
Fig
.
19
.
Front
ABS
wheel
speed
electrical
connector
(arrow)
in
wheel
well
.

6
.
Installation
is
reverse
of
removal
.

510-4



EXTERIOR
TRIM,
BUMPERS

Fig
.
8
.



Bumper
cover
retaining
screws
(arrows)
in
left
wheel
weil
.

7
.
Disconnect
harnessconnectors
at
outside
temperature



0013052

sensor
at
rear
of
left
side
of
bumperand
temperatura



Fig
.
9
.



Front
bumper
impact
absorber
mounting
nuts
(A)
and

switch
at
rear
of
right
side
of
bumper
(if
applicable)
.



bumper
bracket
hardware
(B)
.

8
.
Slide
bumper
straight
off
sida
brackets
.

9
.
Installation
is
reverse
of
removal,
notingthe
following
:



When
removing
and
installing
therear
bumper
or
its
compo-

"
Slide
side
brackets
on
bumper
and
body
carefully
to-



nents,
referto
Fig
.
10
.

gether
.

"
Make
sure
tabs
on
trim
strip
engage
slots
in
bumper



1
.
Raise
and
properly
support
vehicle
.

correctly
.

Tightening
Torque

"
Bumper
to
bumper

bracket
(M8
nut)
............
...
.
.
22
Nm
(16
ft-Ib)

2
.
Working
under
bumper,
remove
screws
or
expansion

Front
bumper
impact
absorber,replacing



rivetsat
corners
and
middle
of
lower
bumper
panel
.
Pull

panel
backward,
uncoupling
it
from
bumper
cover
.
See

Thebumper
mounting
bracket
and
impact
absorber
mount-



Fig
.
11
.

ing
hardware
are
accessible
with
the
Font
bumper
removed,
as
described
above
.
See
Fig
.
9
.



3
.
Remove
bumper
cover
expansion
rivets
and
screws
in-

side
left
and
right
rear
wheel
wells
.

NOTE
-

Install
the
bumper
bracket
boltwith
thread
locking
com-
pound
suchas
Loctite
8
270
or
equivalent
.

Tightening
Torques

"
Bumper
bracket
to
impact
absorber

(M10
nut)
.
..
.
...
.............:.
55
Nm
(41
ft-Ib)
"
Impact
absorber
to
chassis
(M6
nut)
...
9
Nm
(7
ft-Ib)

BUMPERS

Rear
bumper,
removing
and
installing

WARNING
-

Make
sure
that
the
car
is
firmly
supported
on
jack

stands
designad
for
the
purpose
.
Place
the
jack

stands
beneath
a
structural
chassis
point
.
Do
not

place
jack
stands
under
suspension
parts
.

4
.
Remove
left
and
right
bumper
bracket
mounting
bolts

and
remove
bumper
.
See
Fig
.
12
.

5
.
Installation
is
reverse
of
removal
.

NOTE-

Install
the
bumper
bracket
bolt
with
thread
locking
com-
pound
suchas
Loctite®270
or
equivalent
.

Convertible
Top
Lid

The
components
of
the
convertible
top
lid
are
shown
in
Fig
.
20
.

Fig
.
20
.
Components
of
the
convertible
top
lid
.

ROLLOVER
PROTECTION
SYSTEM

The
lid
latches
are
cable
operated
by
a
drive
motor
located
in
the
left
sideof
the
luggagecompartment,
behind
the
trim
lin-

er
.
The
same
motor
is
used
to
raise
and
lower
the
lid
during

automatic
convertible
topoperation
.

The
latch
cables
must
be
adjusted
so
that
the
lidfits
snugly
against
the
body
when
locked
.

The
lid
drive
motor
can
be
removed
and
replaced
from
the

luggage
compartment
.

Two
spring-locaed
cassettes
are
mounted
behind
the
rear
seat
.
A
single
rollover
sensor,
mounted
on
the
left
cassette,
signals
the
convertible
top
module
(CVM)
of
animminent
roll-
over,
whereupon
the
module
triggers
both
cassettes
within

3j10th
of
a
second
.
See
Fig
.
21
.

Once
the
cars
ignition
has
been
switched
on,
the
rollover

sensor
performs
a
self-test
lasting
6
seconds
.
During
this
time

a
yellow
warning
light
is
lit
on
the
dashboard
.
If
thewarning
lightfails
to
go
out
after
6
seconds,
this
means
that
a
fault
has

been
detected
in
the
system
.
The
fault
is
stored
in
the
CM

Faults
canbe
retrieved
and
diagnosedby
special
diagnostic

equipment
.

NOTE-

Diagnosis
of
the
convertible
top
and
the
Rollover
Pro-
tection
System
are
beyond
the
scope
of
this
book
.
Your
authorized
BMW
dealer
has
the
proper
diagnostic
equipment
and
tools
to
carry
out
these
tasks
.

CONVERTIBLE
TOP



541-
9

Fig
.
21
.
Construction
of
the
rollover
protection
cassette
.

After
deployment,
thedetent
pawl
in
a
rollover
protection
cassette
can
be
retracted
using
the
special
tool
in
the
tool
kit,
fitted
to
the
screwdriver
handle
.
The
rear
seatheadrest
needs
to
be
raised
for
this
procedure
.

WARNING
-

Ensure
that
the
area
above
and
adjacent
to
the
roll-
over
bars
remains
clear
and
unobstructed
at
all
times
.

CAUTION-

"
Itis
not
possible
to
close
the
convertible
top
with
the
rollover
bars
extended
.

"
If
a
hardtop
is
mounted,
be
sure
to
install
the
pro-
tective
rollover
bar
covers
provided
with
the
hard-
top
to
prevent
damaglng
the
rear
window
in
case
of
deployment
.

0012744

ROLLOVER
PROTECTION
SYSTEM

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