1997 BMW 328i rear

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

260-
4
DRIVESHAFT

CAUTION
-

The
maximum
allowable
change
in
height
of
the

center
bearing
or
transmission
support
using

shims
is
3
mm
(0
.12
in
.)
.

Driveshaft,
removing

WARNING
-

"
Be
sure
the
wheels
are
off
the
ground
before
re-

moving
the
driveshaft
.
Set
the
parking
brake
be-

fore
removing
the
driveshaft
.

"
Once
the
driveshaft
has
been
removed,
the
vehi-
cle
can
roll
regardless
of
whether
the
transmis-
sion
isin
gear
or
not
.

"
The
driveshaft
fs
mounted
to
thetransmission
and
final
drive
with
self-locking
nuts
.
These
nuts

are
designed
to
be
used
only
once
and
should
be

replaced
during
reassembly
.

1.
Disconnect
oxygen
sensor
electrical
connectors
and
remove
complete
exhaustsystem
.
See
180
Exhaust

System
.

4
.
Remove
driveshaft
mounting
bolts
.
See
Fig
.
3
.
Discard

old
nuts
.

JG

Fig
.
3
.



Front
driveshaft
totransmission
mounting
bolt
being
re-
moved
.
Note
open-end
wrench
(arrow)
being
used
to
coun-
terhold
bolt
.

5
.
Loosen
threaded
clamping
sleeve
on
driveshaft
a
few
tucos
.
See
Fig
.
4
.

DRIVESHAFT
SERVICE

Fig
.
4
.



Threaded
clamping
sleeve
nut
being
loosened
.

0012037

6
.
Support
driveshaft
andremove
center
support
bearing

mounting
bolts
.

7
.
Remove
driveshaft
but
do
not
separate
two
halves
.
Pull

down
on
center
of
driveshaft
to
facilitate
removal
.

2
.
Remove
exhaust
heat
shield
and
heat
shieldcross-

member
.



NOTE-

If
driveshaft
halves
were
separate
and
not
match-

3
.
Matchmark
front
and
rear
driveshaft
connections
at



marked,
assemble
driveshaft
as
shown
in
drawing
.
If
a

transmissíon
and
final
drive
.



vibration
occurs,
disassemble
driveshaftand
rotate
one

section
180°
.
See
Fig
.
5
.

Driveshaft,
installing

Fig
.
5
.



Driveshaft
alignment
.
Centerlinesof
universal
joints
(arrows)

must
be
parallel
or
at
90°
to
each
other

1
.
Align
driveshaft
matchmarks
at
final
drive
and
then
at

transmission
flange
.
Start
attaching
nuts
.
Use
new
self-

locking
nuts
.

2
.
Position
center
support
bearing
and
start
attaching

nuts
.
Use
new
self-locking
nuts
.

3
.
Tighten
flangenuts
while
preventing
bolts
from
twisting

in
coupling
.
Tighten
final
drive
flange
first,
then
tighten

coupling
at
transmission
.

4
.
Preload
center
support
bearing
by
pushing
bearing
for-
ward4-6
mm
(0
.16-0
.24
in
.)
from
center
.
See
Fig
.
6
.
Tighten
attaching
bolts
.

Fig
.
6
.



Preload
center
bearing
toward
front
4-6
mm
(arrow)
.

5331
5
.
Tightenthreadedsleeveondriveshafttopropertorque
.

6
.
Insta¡¡
heat
shield
and
heat
shield
crossmember
.

Tightening
Torques

"
Driveshaftcenter
mount
to
body
.
.
..
21
Nm
(16
ft-Ib)

"
Driveshaft
clamping
sleeve
.....
.
.
.
10
Nm
(89
in-lb)

"
Driveshaft
to
final
drive
flange

With
CV
joint
(M8)
............
...
32
Nm
(23
ft-Ib)

Wth
U-joint
(M10
ribbed
nut)
....
...
80
Nm
(59
ft-Ib)

With
U-joint
(M10
compressed
nut)
..
60
Nm
(44
ft-Ib)

"
Flex-disc
to
driveshaft
or
transmissionflange

M10
(8.8
grade)
.........
.
....
..
.
48
Nm
(35
ft-Ib)

M10
(10
.9
grade)
........
.
....
...
64
Nm
(47
ft-Ib)

M12
(8.8
grade)
........
.....
..
.
.
81
Nm
(60
ft-Ib)

M12
(10
.9
grade)
.
.
....
......
...
100
Nm
(74
ft-Ib)

M12
(10
.9
grade)
(M3
models)
..
.
.
.
115
Nm
(85
ft-Ib)

"
Transmission
crossmember

to
body
(M8)
.
....
...........
....
21
Nm
(16
ft-Ib)

NOTE-

Bolt
grade
is
markedon
the
bolt
head
.
When
replacing
bolts,
only
use
bolts
of
the
same
strength
and
hardnessas
the
originalsinstalled
.

Flex-disc,
replacing

The
flex-disc
between
the
front
section
of
the
driveshaft
and

theoutputflange
of
the
transmission
should
be
checked
for

cracks,
tears,
missing
pieces,
or
distortion
.
Check
for
worn
bolt
hole
bores
in
theflange
.

1
.
Remove
driveshaft
as
described
in
Driveshaft,
remov-
ing
.

NOTE-

¡t
is
possible
to
only
partially
remove
the
driveshaft,
leaving
it
connected
to
the
final
drive
.
The
driveshaft
canbe
tilted
down
in
thecenter
and
slidoff
the
trans-
mission
flange
once
the
clamping
sleeve
is
loosened
and
the
center
bearing
bracket
is
unbolted
.
Suspend
the
driveshaft
using
stiff
wire
in
as
close
to
the
installed
position
as
possible
.
If
the
driveshaft
hangs
unsupport-
ed,
the
rear
universal
joint
may
be
damaged
.

2
.
Unbolt
flex-dísc
from
driveshaft
.

DRIVESHAFT
260-
5

7
.
Install
exhaust
system
.
See
180
Exhaust
System
.

Connect
wiring
harness
to
oxygen
sensors
.



NOTE-

Removaland
installation
of
the
boltsmaybe
made
eas-
8
.
Road
test
vehicle
to
check
for
noiseor
vibration
.



ier
by
placing
a
large
hose
clamp
around
the
flex-disc,
and
tightening
the
clamp
slightlyto
compress
the
cou

WARNING
-



pling
.

"
Do
not
reuse
self-locking
nuts
.
These
nuts
aredesigned
to
beused
only
once
.



3
.
Insta¡¡
new
flex-disc
using
new
self-locking
nuts
.
Mold-

"
Avóid
stressing
the
flex-disc
when
torquing
the



ed
arrows
on
coupling
should
face
flange
arms
.
See

bolts
Do
this



holding
the
bolts



Fig
.
7
.
steady
and
.



uy
turning
the
nuts
on
theflange
side
.

5
:132

Fig
.
7
.



When
attaching
flex-disc,
molded
arrows
must
point
toward

flange
arms
.

DRIVESHAFT
SERVICE

260-
6
DRIVESHAFT

4
.
Insta¡¡
driveshaft
as
described
in
Driveshaft,
install-

ing
.

Tightening
Torques

"
Driveshaft
center
mount
to
body
.
...
21
Nm
(16
ft-Ib)

"
Driveshaft
clamping
sleeve
.....
...
10
Nm
(89
in-lb)

"
Driveshaft
to
final
drive
flange

With
CV
joint
(M8)
............
...
32
Nm
(23
ft-Ib)

Wth
U-joint
(M10
ribbed
nut)
......
.
80
Nm
(59
ft-Ib)

With
U-joint
(M10
compressed
nut)
.
.
60
Nm
(44
ft-Ib)

"
Flex-disc
to
driveshaft
or
transmission
flange

M10
(8
.8
grade)
.
...
.............
48
Nm
(35
ft-Ib)

M10
(10
.9
grade
.
...
.............
64
Nm
(47
ft-Ib)

M12
(8
.8
grade)
..
..
.............
81
Nm
(60
ft-Ib)

M12
(10
.9
grade)
.
..
............
100
Nm
(74
ft-Ib)

M12
(10
.9
grade)
(M3
models)
.....
115
Nm
(85
ft-Ib)

"
Transmission
crossmember

to
body
(M8)
......
...
.
..
........
21
Nm
(16
ft-Ib)

5
.
Remove
center
bearing
circlip
and
dust
guard
.
See
Fig
.

Center
bearing
assembly,
replacing



10
.
Remove
bearing
from
driveshaft
using
puller
.

To
replace
thecenter
bearing
assembly,
the
driveshaft

must
be
removed
from
thecar
.
The
center
bearing
assembly

consists
of
a
grooved
ball
bearing
in
a
rubber
mount
.
The

bearing
assembly
is
pressed
onto
the
front
section
of
the

driveshaft
and
securedby
a
circlip
.
See
Fig
.
8
.

Circlip

NOTE
-

Torque
only
the
nuts
while
holding
the
bolt
heads
.
Thís
will
prevent
damaging
or
fatiguing
the
rubber
.

Dust
cap

Fig
.
8
.



Exploded
view
of
driveshaft
support
bearing
assembly
.

1
.
Remove
driveshaft
.
See
Driveshaft,
removing
.

DRIVESHAFT
SERVICE

0012594

5333

Fig
.
9
.



Before
pulling
apart
driveshaft
sections,
make
matching
marks
as
shown
.

4
.
Inspect
condition
of
rubber
bushing
for
splined
cou-

pling
.
Replace
worn
or
damaged
parts
.

2
.
Make
matching
marks
on
front
and
rear
driveshaft
sec-



NOTE-

tions
.
See
Fig
.
9
.



Install
puller
so
that
it
pulls
on
inner
hub
of
bearing
.
Pulling
on
outer
ring
of
mount
may
tear
rubber,
and
en

3
.
Loosen
clamping
sleeve
fully
and
pull
driveshaft
sec-



tire
bearing
assembly
will
need
to
be
replaced
.

tions
apart
.
Remove
rubber
bushing,
washer,
and
clamping
sleeve
from
front
section
.

5334

Fig
.
10
.
Center
bearing
circlip
(arrow)
to
be
removed
.
Driveshafl
shown
installed
.

SUSPENSION,
STEERING
ANDBRAKES-GENERAL



300-1

300
Suspension,
Steering

and
Brakes-General

GENERAL
.....
.
....
.
.....
.
.
.
........
.300-1



M3
SUSPENSION
AND
BRAKES
.......
.
...
300-7

Front
Suspension
..........
.
.
.
...
.
.....
300-1

Steering
...
.
.
.
.
.
....
.
.
.
...
.
.
.
...
.
...
.
.
300-2



SUSPENSION
AND
STEERING

Rear
Suspension
....
.
.
.
...
.
.
.
...
.
.....
300-2



TROUBLESHOOTING
..
.
.
.
.............
300-7

Brakes
.
.
.
.
.
.
.
.
....
.
...........
.
.
.
.
.
.
300-2

Tires
and
wheeis
.
................
.
.
.
.
.
.
300-2



TABLE

a
.
AST
Indicator
Lamp
Function
..
..
.
..
.
.........
300-5

INTEGRATED
SYSTEMS
.........
.
.
.
.
.
.
300-2



b
.
Suspension
and
Steering
Troubleshooting
......
.300-8

Antilock
Brake
System
(ABS)
.......
.
.
.
.
.
.
300-2

Al¡
Season
Traction
(AST)
.........
.
.
.
.
.
.
300-4

GENERAL



Front
Suspension

This
section
covers
general
information
for
front
and
rear



The
lower
control
arms
connect
the
front
suspension
struts

suspension,
the
steering
system,
and
the
brakíng
and
traction



to
mounting
points
on
the
subframe
crossmember
and
the

control
systems
.



body
.
See
Fig
.
2
.

The
BMW
E36
suspension
and
steering
systems
are
engi-

neered
to
provide
a
compromise
between
taut,
responsive
handling
and
ride
comfort
.
Although
the
front
and
rear
suspen-
sion
assemblies
are
independent
subsystems,
they
work
to-

gether
to
achieve
BMW's
overall
combination
of
precise

handling
and
comfort
.
See
Fig
.
1
.

Fig
.
1
.



BMW
E36
front
and
rear
suspension
systems
.

Each
front
strut
assembly
includes
a
shock
absorber
car-

tridgeinside
the
tubular
strut
housing
and
a
large
coil
spring
.

The
upper
strut
mount
bearing
allows
the
strutto
turnwith
the

wheels
.
The
lower
end
of
the
strut,
which
includes
the
stub
axle
for
the
front
wheel,
connects
to
a
ball-joint
on
the
control
arm
.

0013098

GENERAL

300-2



SUSPENSION,
STEERING
AND
BRAKES-GENERAL

Steering

INTEGRATED
SYSTEMS

The
steering
linkage
connects
the
rack-and-pinion
unit
through
tie
rodsto
the
steering
arms
.
The
tie
rod
ends
allow
the
wheels
to
pivot
and
react
to
suspension
travel
.

Rear
Suspension

The
rear
axle
carrier
is
the
main
mounting
point
for
the
final

drive
housing
and
the
rear
suspension
components
.

Trailing
arms
locatethe
rear
wheels
and
anchorthe
springs,

shocks
and
stabilizer
bar
.
Driveaxies
with
constant-velocity

(CV)
joints
at
both
ends
transfer
power
from
the
differential
to

the
road
wheels
.
The
differential
is
mounted
to
the
rearaxle

carrier
through
rubber
mountsand
bushings
to
hele
isolate

drivetrain
noise
and
vibration
.

Brakes

E36
cars
areequipped
with
power
disc
brakes
with
an
inte-
gral
antilock
brakes
(ABS)
.
The
parking
brake
is
a
dual-drum

system
integrated
with
the
rear
brake
rotors
.
See
Fig
.
3
.

Power
assist
is
provided
by
a
vacuum
booster
when
the
en-

gine
is
running
.
The
brakepedal
pushrod
is
connected
directly

to
the
master
cylinder,
so
failure
of
the
vacuum
booster
does

not
normally
result
in
total
brake
failure
.

0012124



Each
disc
brakeuses
a
caliper
with
a
single
hydraulic
cylin-
Fig
.
2
.



Front
suspension
control
arm
(arrow)
.



der
.
Brake
pads
in
the
left
front
and
right
rear
contain
wear

sensors
.
When
the
padsneed
replacement,the
sensors
illu-
The
front
suspension
is
designed
with
minimum
positive



minate
a
light
on
the
dashboard
.
steering
offset
.
This
geometry
contributes
to
stability
when

traction
is
unequalfrom
side
to
side
.
Suspension
travel
is
lim-



Tires
and
Wheels
ited
by
rubber
bump
stops
.

The
three
point
mounting
of
each
L-shaped
control
arm
ere-



Tiresize
is
critica¡
to
the
proper
operatíon
of
the
E36
ABS
or

cisely
controls
the
front-to-rear
and
side-to-side
position
of
the



ABS/AST
system
.
Severa¡
different
styles
of
wheels,
in
15,16

strut,
while
the
flexibility
of
the
joints
and
mounts
alsoallows



and
17
inch
diameters,
are
available
from
an
authorized
BMW

the
movement
necessary
for
suspension
travel
.
The
control



dealer
.

arm
mounting
points
are
designed
with
anti-dive
geometry
.

The
suspension
reduces
the
normaltendency
for
the
front
of



NOTE-
the
vehicle
to
dive
under
hard
braking
.



Aftermarket
wheelsshould
be
selected
wlth
care
.
Im-
properly
fitted
wheels
can
contact
anddamage
sus

Control
arm
position
is
fixed,
with
no
adjustment
provisions



pension,
brakeorbodycomponentsandmayadversely

on
the
control
arms
for
alter¡ng
front
wheel
al
ignment
.
A
stabi-



affect
vehicle
stability
.

lizer
bar
mounted
to
both
control
arms
heles
to
reduce
body
rol¡
whencomering
.



INTEGRATED
SYSTEMS

Antilock
Brake
System
(ABS)
is
standard
on
all
E36
cars
.

The
variable-assist
power
steering
system
consists
of
an



Standard
on
some
models
and
installed
as
optional
equipment
on

engine-driven
hydraulic
pump,
a
rack-and-pinion
type
steer-



others,
is
All
Season
Traction
(AST)
.

ing
gear,
and
connecting
linkage
to
the
road
wheels
.
TheE36
utilizes
an
engine-speed
dependent
variable
effort
steering



Antilock
Brake
System
(ABS)

system
.
At
low
speeds,
maximum
power
assist
is
provided
to
ease
parking
and
city
driving
.
Athigh
speeds,
assist
is
re-



The
electronically-controlled
ABS
maintains
vehícle
stabili
duced
to
ensure
stability
.



ty
and
control
during
emergency
braking
by
preventing
wheel
lock-up
.
ABS
provides
optimum
deceleration
and
stability
dur-

300-4



SUSPENSION,
STEERING
AND
BRAKES-GENERAL

Three-channel
ABS
ís
used
on
al[
E36
cars
equipped
with



Al¡
Season
Traction
(AST)
standard
ABS
.
Each
front
wheelhas
a
separate
solenoid

valve
to
modulate
hydraulic
pressure
to
that
brake
caliper
.



The
traction
control
system
works
in
conjunction
with
ABS
The
rear
wheels
are
modulated
asa
pair,
controlled
by
a
sin-



and
the
engine
management
system
to
enhance
vehicle
con
gle
solenoid
valve
.



trol
.
The
main
function
of
the
AST
system
is
to
maintain
the
rolling

contact
between
the
tires
and
the
road
surface
under
al¡
driving
E36
cars
equipped
with
ABS/AST
utilize
a
four
channel
sys-



conditions
.
This
is
achieved
through
exact
application
and
tem,
which
functionsexactly
as
the
three
channelsystem



management
of
braking
and
drivetrain
forces
.
above,except
that
the
rear
wheels
are
modulated
individually
.

IDLE
SPEED
CONTROL
VALVE

HROTTLE
PLATE

6
.

Í
III

i



ADS
ACTU
AT
OR

THROTTLE
PLATE
POSITION
SENSOR

DME

Fig
.
6
.
All
Season
Traction
(AS)
works
withother
drivetrain
systems
to
enhance
vehicle
control
.

INTEGRATED
SYSTEMS

The
throttle
control
system
used
in
AST
is
illustrated
in
Fig
.

MASS
AIR
FLOW
SENSOR

JADS
THROTTLE
PLATE
POSITION
SENSOR

0013006

NOTE-

The
traction
control
system
referred
to
as
AST
(all
sea-
son
traction)
may
also
be
referred
to
as
ASC
(Automat-
ic
Stability
Control)
and
ASC+T
(Automatic
Stability
Control+Traction)
.

The
AST
system
improves
traction
by
electronically
apply-

ing
the
rear
brakes
when
therear
drive
wheels
are
spinning
at

a
faster
rate
than
the
front
wheels
.
The
combined
ABS/AST

control
module,
operating
through
the
ABS
hydraulic
control

unit,
modulates
braking
force
at
therear
wheels
.

In
addition,
AST
uses
retarded
ignition
timing
and
an
auxil-iary
engine
throttle
plate
to
reduceengine
torque
and
maintain

vehicle
stability
.

The
auxiliary
throttle
plate
is
held
open
by
spring
pressure
.

The
AST
system
actívates
the
auxiliary
throttie
position
motor

(ADS)
to
cose
the
AST
throttle
as
needed
.
This
reduces
the

volume
of
engine
intake
air
.
Due
to
the
throttle
closing
very
rapidly
during
AST
operationthe
driver
cannot
increase
theengine
power
output
regardless
of
how
far
theaccelerator
pedal
is
pushed
to
the
floor
.

The
auxiliary
throttle
plate
is
placed
ahead
of
the
conven-

tional
throttle
plate
in
the
throttle
body
.

Traction
control
also
comes
into
operationduringdecelera-
tion
.
Decelerating
on
snowy
or
icy
road
surfaces
can
lead
to
rear
wheel
slip
.
If
a
rear
wheel
startsto
drag
or
lock
up
when

the
throttle
is
closed
rapidly
orduringdownshifting,the
AST
system
can
limit
the
problem
by
advancing
the
ignition
timing
.

A
switch
on
the
center
console
is
used
to
togglethe
AST
on

or
off
.

The
AST
system
is
designed
to
be
maintenance
free
.
There

are
no
adjustments
that
can
be
made
.
Repair
and
trouble-
shooting
of
the
AST
system
requires
special
test
equipment

andknowledgeand
should
be
performed
only
by
an
autho-

rized
BMW
dealer
.
Table
a
lists
theconditions
indicated
by

the
AST
indicator
light
in
the
instrument
cluster

SUSPENSION,
STEERING
AND
BRAKES-GENERAL



300-5

Tablea
.
AST
Indicator
Lamp
Function

Indicator
lamp



1
Condition



1
Comment

Light
on



Normal
AST
start-



Automatic
AST
up



self-test

Light
off



AST
monitoring



Automatic
AST
op-
mode



eration

Press
AST
button,



AST
off
(disabled)



Rocking
the
car
tolight
comes
on



getout
of
snow
or
other
loose
surface
Driving
with
snow
chains

Press
AST
button
:



AST
monitoring



Automatic
AST
op-
light
goes
out



I
mode



eration

Light
flashes



AST
active
mode



I
Normal
AST
oper-
ation
as
it
controls
wheel
speed

Light
stays
on
af-



Defect
in
AST



Consult
BMW
ter
start
up
or



dealer
for
diagno-
comes
on
while



sis/repair
driving



(Vehicle
operation
remains
normal)

WARNING
-

Even
a
car
with
AST
is
subject
to
the
normal
physi-
cal
laws
.
Avoid
excessive
speeds
for
the
road
con-
ditions
encountered
.

CAUTION-
"
If
the
tires
on
the
carare
of
different
makes,
the
AST
system
may
over-react
.
Only
fit
tires
of
the
same
make
and
tread
pattem,

"In
adverse
conditions,
such
as
trying
to
rock
the
car
outof
deep
snow
or
another
soft
surface,
or
when
snow
chainsare
fitted,
it
is
advisable
to
switch
off
AST
and
allow
the
cars
driveline
to
op-
erate
conventionally
.

INTEGRATED
SYSTEMS