intake BMW 325i 1994 E36 Manual PDF
Page 179 of 759
Table
j.
ECM
Pin
Assignment-Bosch
DME
M3
.3
.1
Pin
~
Signal
1
Componentffunction
1
signal
FUEL
INJECTION
130-
33
45
ground
Ignition
circuit
shield
Ground
shieldfor
ignition
circuit
monitoring
46
output
Fuel
consumption
(KVA
signal)
To
instrument
cluster
47
output
Crankshaft
rpm
Engine
speed
(TD)
signal
to
instrument
cluster
48
output
A/C
compressor
control
A/C
compressor
relay
terminal
85
49
vacant
-
-
50
output
Ignition
coil
control,
cyl
.
1
Primary
signal,
ignition
coil
1
51
output
Ignition
coil
control,
cyl
.
2
Primary
signal,
ignition
coil
2
52
output
Ignition
coil
control,
cyl
.
3
Primary
signal,
ignition
coil
3
53
vacant
-
-
54
input
Power
supply
Battery
voltagefrom
main
relay
(terminal
87a)
55
ground
Ground
Ground
for
ignition
control
56
input
Power
supply
(terminal15)
Batteryvoltage
with
key
on
or
engine
running
57
input
Ignition
timing
intervention
From
A/T
control
module
58
vacant
-
-
59
output
Throttleposition
sensor
(TPS)
Voltage
supply
to
TPS
(5
VDC)
60
input
Programming
voltage
Data
link
connector
61
vacant
-
-
62
vacant
-
-
63
vacant
-
-
64
input
A/C
on
signal
From
integrated
climate
control
module
65
input
A/C
pressure
signal
From
integrated
climate
control
module
via
A/C
pressure
switch
66
input
On-board
computer
Drive-away
protection
enable
(starter
immobilization
relay)
67
vacant
-
-
68
vacant
-
-
69
input
Knock
sensor
#2
(cyl
.
4,5,
6)
Knock
sensor
#2
signal
70
input
Knock
sensor
#1
(cyl
.
1,2,
3)
Knock
sensor
#1
signal
71
ground
Ground
Ground
for
knock
sensors
and
shields
72
vacant
-
-
73
input
Throttleposition
sensor
(TPS)
Throttleposition
signal
74
vacant
-
75
vacant
-
-
76
vacant
-
77
input
Intakeair
temperatura
Intakeair
temperatura
sensor
(0-5
VDC)
78
input
Engine
coolant
temperature
Engine
coolant
temperature
sensor
(0-5
VDC)
79
vacant
-
80
vacant
-
-
81
input
Automatic
transmission
gear
positionlneutral
A/T
parkor
neutral
position
signal
safetyswitch
82
vacant
-
-
83
vacant
-
-
84
vacant
-
-
85
vacant
-
-
86
vacant
-
-
87
input
Diagnostic
connector
(RxD)
Diagnostic
RxD
(receive)
signal
to
pin
15
in
Data
link
connector
88
input/output
Diagnostic
connector
(TxD)
Diagnostic
TxD
(transmit)
signal
to
pin
20
in
Data
link
connector
ECM
PIN
ASSIGNMENTS
Page 180 of 759
130-
34
FUEL
INJECTION
Pin
i
Signal
1
Component/function
1
Signal
1
output
Oxygen
sensor
(monitoring
sensor)heater
Oxygen
sensor
heater
control
(switched
ground)
2
output
Idle
speed
control
valve
Pulsed
ground-close
signal
(see
also
pin
29)
3
output
Fuel
injector
control,
cyl
.
1
Pulsed
ground
(injection
pulsewidth
in
ms)
cyl
.
1
4
output
Fuel
injector
control,
cyl
.
4
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
4
5
not
used
-
-
6
ground
Ground
Ground
for
fuel
injector
output
stage
7
not
used
-
8
1
output
1
Check
Engine
1
Instrument
cluster,
Check
Engine
lamp
9
not
used
-
-
10
input
Electronic
immobilizer
control
(EWS
II)
Electronic
immobilizer
control
(EWS
II)
module
11
output
Automatic
climate
control
Automatic
climate
control,
to
evaporator
controlier
12
not
used
-
-
13
not
used
-
-
14
not
used
-
-
15
not
used
-
-
16
input
Intake
air
temperature
Intake
air
temperature
Signal
17
input
Mass
air
flow
meter
Intake
air
signal
18
not
used
-
-
19
input
Oxygen
sensor
(monitoring
sensor)
Oxygen
sensor
control
20
output
Crankshaft/rpm
sensor
Crankshaft/rpm
sensor
control
21
input
Camshaft
position
sensor
Camshaft
position
signal
22
output
Ignition
coil
control,
cyl
.
3
Primary
signal,
ignitioncoil
3
23
output
Ignition
coil
control,
cyl
.
4
Primary
signal,
ignitioncoil
4
24
not
used
-
-
25
not
used
-
-
26
input
Power
supply
(terminal
30)
Battery
voltage
(B+)
at
al¡
times
27
input
Main
relay
control
Main
relay
activation
(terminal
85)
28
ground
Ground
Ground
for
ECM
and
sensor
shielding
29
output
Idle
speed
control
valve
Pulsed
ground-open
signal
(seealsopin
2)
30
output
Oxygen
sensor
(monitoring
sensor)
heater
Oxygen
sensor
heater
control
(switched
ground)
31
output
Fuel
injectorcontrol,
cyl
.
3
Pulsed
ground
(injection
pulsewidth
in
ms)
cyl
.
3
32
output
Fuel
injector
control,
cyl
.
2
Pulsed
ground
(injection
pulsewidth
in
ms)
cyl
.
2
33
I
not
used
40
input
Knock
sensor
#2
(cyl
.
3,4)
Knock
sensor
#2
signal
41
not
used
-
-
42
input
Vehicle
speed
Vehicle
speed
signal
from
instrument
cluster
43
not
used
-
-
44
output
Throttleposition
sensor
(TPS)
Throttleposition
reference
signal
ECM
PIN
ASSIGNMENTS
Table
k
.
ECM
Pin
Assignment-Bosch
DME
M5
.2
34
ground
Ground
Ground
for
ECM/
output
stages
35
not
used
-
-
36
input
A/C
compressor
relay
A/C
compressor
relay
control
37
not
used
-
-
38
not
used
-
-
39
not
used
-
-
Page 181 of 759
Table
k
.
ECM
Pin
Assignment-Bosch
DME
M5
.2
(continued)
Pin
I
Signal
1
Componentltunction
1
Signal
45
I
output
I
Mass
air
flow
meter
I
Intake
airSignal
46
output
Oxygen
sensor
(monitoring
sensor)
Oxygen
sensor
control
47
not
used
-
48
not
used
-
49
output
Ignition
coil
control,
cyl
.
1
Primary
signal,
ignition
coil
1
50
output
Ignition
coil
control,
cyl
.
2
Primary
signal,
ignition
coil
2
51
not
used
-
52
not
used
-
53
input
Throttleposition
sensor
Throttleposition
Signal
54
input
Power
supply
Batteryvoltage
from
main
relay
(terminal
87)
55
ground
Ground
Ground
for
ECM
56
input
Power
supply
(terminal
15)
Battery
voltage
with
key
on
or
engine
running
57
output
Activate
cooling
fan
(man
.
trans
.)
control
Normal
speed
relay
58
not
used
-
-
59
not
used
-
-
60
input
Programming
voltage
Programming
voltage
via
data
link
connector,
pin
18
61
output
Evaporative
emissionvalve
Evaporative
emission
valve
control
62
vacant
-
-
63
output
Fuel
pump
relay
Fuel
pump
relay
control
64
not
used
-
65
not
used
-
-
66
not
used
-
-
67
not
used
-
-
68
input
Signal
above
80°C(man
.
tran
.)
Double
temperature
switch
69
input
Automatic
climate
control
Automatíc
climate
control
70
input
Knock
sensor
#1
(cyl
.
1,2)
Knock
sensor
#1
Signal
71
ground
Ground
Ground
for
analog
signals
and
knock
sensors
72
not
used
-
-
73
not
used
-
-
74
input
Engine
coolant
temperature
sensor
Engine
coolant
temperatura
Signal
75
not
used
-
-
76
not
used
-
-
77
output
Oxygen
sensor
(regulating
sensor)
Oxygen
sensor
control
78
input
Crankshaft/rpm
sensor
Crankshaft
position/rpmSignal
79
input
ABS
or
traction
control
ABS
or
AST
control
80
input
Engine
speed
Engine
speed
Signal
81
not
used
-
-
82
not
used
-
-
FUEL
INJECTION
130-
3
5
83
input
On-board
computar
From
On-boardcomputer
(terminal
4)
84
not
used
-
-
85
not
used
-
-
86
not
used
-
-
87
input
Diagnostic
connector
(RxD)
Diagnostic
RxD
(receive)signal
to
pin
15
in
Data
link
connector
88
output
I
Diagnostic
connector
(TxD)
Diagnostic
TxD
(transmit)
signal
to
pin
17in
Data
link
connector
ECM
PIN
ASSIGNMENTS
Page 182 of 759
130-
3
6
FUEL
INJECTION
Pin
1
Signal
1
Componentffunction
1
Signal
1
output
Ignition
coil
control,
cyl
.
2
Primary
signal,
ignition
coil
2
2
output
Ignition
coil
control,
cyl
.
4
Primary
signal,
ignitioncoil
4
3
output
Ignition
coil
control,
cyl
.
6
Primary
signal,
ignition
coil
6
4
ground
Ground
Ground
5
output
Fuel
injectorcontrol,
cyl
.
2
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
2
6
output
Fuel
injectorcontrol,
cyl
.
1
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
1
7
output
Mass
air
flow
meter
Mass
air
meter
signal
8
input
Mass
air
flow
meter
Mass
air
meter
signal
9
output
Instrument
cluster
Fuel
consumption
signal
10
output
Engine
coolant
temperature
(ECT)
sensor
ECT
signal
11
output
Fueltankpressure
sensor
Fueltankpressure
sensor
control
12
input
Throttleposition
sensor
(TPS)
Throttleposition
signal
13
-
14
input
Intake
air
temperature
(IAT)
sensor
Intake
air
temperature
signal
15
Traction
control
AST
module
16
input
Automatic
climate
control
Automatic
climate
control
17
18
input
Electronic
immobilizer
control
(EWS
II)
Electronic
immobilizer
control
(EWS
II)
module
19
Automatic
climate
control
Automatic
climate
control
20
-
Instrument
cluster
Instrument
cluster
21
output
Camshaft
actuator
(VANOS
solenoid)
control
Camshaft
actuator
(VANOS
solenoid),
switched
ground
22
output
Fuel
injectorcontrol,
cyl
.
3
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
3
23
Fuel
injectorcontrol,
cyl
.
6
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
6
24
Fuel
injectorcontrol,
cyl
.
4
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
4
25
output
Oxygen
sensor
heater
control
Oxygen
sensor
heater
ground
26
input
Power
supply
(terminal
30)
Battery
voltage(B+)
at
all
times
27
output
Idle
speed
control
valve
Pulsed
ground-open
signal
(see
also
pin
53)
28
ground
Ground
Ground
29
output
Ignition
coil
control,
cyl
.
1
Primary
signal,
ignition
coíl
1
30
output
Ignition
coil
control,
cyl
.
3
Primary
signal,
ignition
coil
3
31
output
Ignition
coil
control,
cyl
.
5
Primary
signal,
ignition
coil
5
32
ground
Ground
Ground
33
output
Fuel
injector
control,
cyl
.
5
Pulsedground
(injection
pulsewidth
in
ms)
cyl
.
5
34
ground
Ground
Ground
35
output
Secondary
air
injection
Secondary
air
injection
pump
relay
control
36
output
Engine
speed
output
Engine
speed
signal
37
-
38
ground
Knock
sensor
Shielding
for
knock
sensors
39
output
Intake
air
temperature
sensor
(IAT
Sensor)
Voltagesupply
to
IAT
sensor
and
ECT
sensorEngine
coolant
temperature
(ECT)
sensor
40
output
Crankshaft
position
sensor
(Hall
effect)
Crankshaft
position
sensor
control
41
ground
Camshaft
position
(CMP)
sensor
Shielding
for
CMP
sensor
42
output
Throttle
position
sensor
(TPS)
TPS
ground
43
input
Camshaft
position/rpm
sensor
Camshaft
position/rpm
sensor
control
44
output
Throttle
position
sensor
(TPS)
Voltagesupply
to
TPS
(5
VDC)
45
Traction
control
AST
module
46
-
Instrument
cluster
Instrument
cluster
ECM
PIN
ASSIGNMENTS
Table
I.
ECM
Pin
Assignment-Siemens
DME
MS
41
.1
Page 192 of 759
160-
8
FUEL
TANK
AND
FUEL
PUMP
UU131
tst5
Fig
.
11
.
Voltage
supply
to
fuel
pump
harness
(black)
connector
being
checked
(arrow)
.
00131ts7
Fig
.
12
.
Test
fuel
pump
for
current
draw
by
attadhing
ammeter
andjumper
wire
as
shown
.
CAUTION-
Do
not
allow
the
test
leads
to
short
to
ground
.
NOTE-
See
600
Electrical
System-General
for
information
on
electricaltests
using
a
digital
multimeter
(DMM)
.
4
.
Run
pump
as
described
in
Operating
fuel
pump
for
tests
.
FUEL
PUMP
5
.
Compare
ammeter
reading
with
specification
listed
in
Table
b
.
Maximum
current
5
.0
amps
consumption
FuelDelivery
Tests
Table
b
.
Fuel
Pump
Current
Checking
fuel
delivery
is
a
fundamental
part
of
trouble-
shooting
and
diagnosing
the
DME
system
.
Fuelpressure
di-
rectly
influences
fuel
delivery
.
An
accurate
fuel
pressure
gauge
will
be
needed
to
make
the
tests
.
There
arethree
significant
fuel
delivery
values
to
bemea-
sured
:
"
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,
suchas
clogged
fuel
filter
.
"
Residual
pressure-the
pressure
maintained
in
the
closed
system
after
the
engine
and
fuel
pump
areshut
off
.
Procedures
for
measuring
the
first
two
quantities
arede-
scribed
here
.
Residual
fuel
pressure
is
checked
using
the
procedurede-
tailed
in
130
Fuel
Injection
.
Relieving
fuel
pressure
and
connecting
fuel
pressure
gauge
WARNING
-
"
Gasoline
is
highly
flammable
and
its
vaporsare
explosive
.
Do
not
smoke
or
work
ona
car
near
heaters
or
other
fire
hazards
when
diagnosing
and
repairing
fuel
system
problems
.
Have
a
fire
extinguisher
available
in
case
of
an
emergency
.
"
When
working
onan
open
fuel
system,
wear
suit-
able
hand
protection
.
Prolonged
contact
with
fuel
can
cause
iflnesses
and
skin
disorders
.
CA
UTION-
Cleanliness
is
essential
when
working
withfuel
circuit
components
.
Thoroughly
clean
the
unionsbefore
disconnecting
fuel
fines
To
prevent
fuel
from
spraying
on
a
hotengine,
system
fuel
pressure
should
be
relieved
before
disconnecting
fuel
lines
.
One
method
is
to
tightly
wrap
a
shop
towel
around
a
fuel
line
fit-
ting
and
loosen
or
disconnect
the
fitting
.
Measuring
fuel
pressure
requires
special
tools
.
Earlier
cars
use
pressure
hose
with
clamps
for
fuel
delivery
.
These
can
be
attached
to
a
fuel
pressure
gauge
below
the
intake
manifold
.
Page 193 of 759
NOTE-
NOTE
-
On
1996
and
later
4-cylinder
cars,
use
BMW
special
"
Use
BMW
pressure
gauge
Part
No
.
133
060,or
an
tool
13
6051
(hose
with
quick
release
coupling)
toat-
equivalent
.
The
fuel
pressure
gauge
should
have
a
tach
pressure
gauge
to
Shraeder
valve
fitting
on
top
of
rangeof
0
to
5bar
(0
to
75
psi)
and
mustbe
securely
the
M44
fuel
rail
.
See
Fig
.
13
.
connected
to
prevent
it
from
coming
loose
under
pres-
sure
.
u012503a
Fig
.
13
.
Fuel
rail
showing
location
of
Shrader
valve
fitting
on
M44
en-
gine
(arrow)
.
Later
model
6-cylinder
fuel
systems
require
BMW
specíal
tool
16
1
050
to
release
fittings
and
connect
the
fuel
gauge
.
See
Fig
.
14
.
0012699
Fig
.
14
.
Fuel
lines
at
rear
of
íntake
manifold
on
M52
engine
.
Use
BMW
special
tool
16
1
050
to
release
fittings
.
If
the
special
tools
arenot
available,
a
length
offuel
line
and
a
T-fitting
can
be
installed
tothe
inlet
fuel
line
and
connected
to
a
fuel
gauge
.
FUEL
TANK
AND
FUEL
PUMP
160-
9
"
On
cars
with
6-cylinder
engine,
thetop
left-side
en-
Bine
cover
will
have
to
be
removed
to
access
the
fuel
rail
.
System
pressure,
testing
System
pressure
is
the
pressure
created
by
the
fuel
pump
and
maintained
by
the
pressure
regulator
.
See
Fig
.
15
.
Sys-
tem
pressure
is
not
adjustable
.
1
.
Remove
fuel
tank
filler
cap
.
Fig
.
15
.
Fuel
pressure
regulator
.
Fuel
pressure
deflects
diaphragm
to
retum
fuel
to
tank
when
pressure
reaches
desired
limit
.
CA
UTION-
The
fuel
pump
is
capable
of
developing
a
higher
pressure
than
that
regulated
by
the
pressure
reg-
ulator
.
In
the
event
the
fuel
pump
check
valve
is
faulty
(stuck
closed),
make
sure
the
fuel
pressure
does
not
rise
aboye
6
.0
bar(87
psi)
.
Damage
to
the
fuel
fines
or
fuel
system
components
could
re-
sult
.
2
.
Connect
in-fine
a
Tfitting
and
fuel
pressure
gauge
to
outlet
hose
atfuel
pump
.
FUEL
PUMP
Page 197 of 759
Cooling
System
Pressure
Test
If
the
engine
overheats
and
no
other
cooling
system
testsindicate
trouble,
the
radiator
may
have
some
pluggedpassag-
A
cooling
system
pressure
test
is
used
to
check
for
internal
es
that
are
restricting
coolant
flow
.
leaks
.
Some
of
the
common
sources
ofinternal
leaks
are
a
faulty
cylinder
head
gasket,
a
cracked
cylinder
head,
or
a
Temperature
Gauge
Quick
Check
cracked
cylinder
block
.
The
coolant
temperature
sensor
is
located
on
the
intake
To
doa
cooling
system
pressure
test,
a
special
pressure
manifold
(left)
side
of
the
cylinder
head,
under
the
intake
man-
tester
is
needed
.
ifold
runners
.
See
Fig
.
2
.
WARNING
-
At
normal
operating
temperature
-
the
cooling
sys-
tem
is
pressurized
.
Allow
the
system
to
cool
before
opening
.
Release
the
cap
slowly
to
allow
sale
re-
tease
of
pressure
.
With
the
engine
cold,instan
a
pressure
tester
to
the
expan-
sion
tank
.
Pressurize
thesystem
to
the
specification
listed
be-
low
.
Pressure
should
not
drop
more
than
0
.1
bar
(1
.45
psi)
for
at
leakt
two
minutes
.
If
the
pressure
drops
rapidly
and
there
is
no
sign
of
an
externa¡
leak,
the
cylinder
head
gasket
may
be
faulty
.
Considera
compression
test
as
described
in
100
En-
gine-General
.
The
screw-on
type
expansion
tank
cap
should
also
be
test-
ed
using
a
pressure
tester
and
the
correct
adapter
.
Cooling
System
Test
Pressure
"
Radiator
test
pressure
.........
.
1
.5
bar
(21
.75
psi)
"
Radiator
cap
test
pressure
..
.
........
2
bar
(29
psi)
CA
UTION-
Exceeding
the
speclfied
test
pressure
could
dam-
age
the
radiatoror
other
system
components
.
Carefully
inspect
the
radiator
cap
for
damage
.
Replace
a
faulty
cap
or
a
damaged
cap
gasket
.
Thermostat
Quick
Check
In
later
models,
the
ECT
sensor
and
the
gauge
sender
are
combined
into
one
sender
unit
.
For
wire
colors
refer
to
Table
a
.
To
check
if
the
thermostat
is
opening
and
coolant
is
circulat-
ing
through
the
radiator,
allow
a
cold
engine
to
reach
operat-
ing
temperature
(temperature
gauge
needieapproximately
centered)
.
Shut
off
engine
.
Feel
the
top
radiator
hose
.
If
the
hose
is
hot
to
the
touch,
the
coolant
is
probably
circulating
cor-
rectly
.
If
there
are
any
cool
areas
in
the
hose
or
radiator,
cool-
ant
flow
to
the
radiator
is
probably
restricted
.
Check
for
a
faulty
thermostat
or
aplugged
radiator
.
NOTE-
A
thermostat
that
is
stuck
open
will
cause
the
engine
to
warmup
slowly
and
run
belownormal
temperature
at
highway
speed
.
A
thermostat
that
is
stuck
closed
will
re-
strict
coolant
flow
to
the
radiator
and
cause
overheating
.
RADIATOR
AND
COOLING
SYSTEM
170-
3
U
.¡ig
.v
Fig
.
2
.
Temperature
gauge
sender
on
M44
engine
.
Temperature
gauge
sender
location
is
similar
on
al]
engines
.
In
early
models,
the
engine
coolant
temperature
(ECT)
sen-
sor
for
the
fuel
injection
and
the
coolant
temperature
gauge
sender
are
located
side
by
side
.
Table
a
.
Coolant
Temperature
Sensor
Wire
Colors
Function
Sensor
Terminal
Wire
colors
location
number
Two
sensors
:
Temperature
Rear
1
Brown/violet
gauge
sender
2
Brown/yellow
ECT
sensor
Front
1
Brown/red
2
Brown
or
Brown/black
One
sensor
:
Temperature
Dual
1
Brown/yellow
gauge
sender
sensor
2
Brown/violet
ECT
sensor
3
Brown/red
4
Brown/black
or
Grey/black
TROUBLESHOOTING
Page 253 of 759
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
Page 254 of 759
300-6
SUSPENSION,
STEERING
AND
BRAKES-GENERAL
BATTE
RY
KL
30
ECM
MAIN
C~
RELAY
KL
15
DSC
SWITCH
LF1
;1~lZZ~
nSLn
l'
z
sJ
WHEEL
RF
c_
.
LR
r_
.
>
RR
ELECTRONIC
BRAKE
LIGHT
SWITCH
SPEED
SENSORS
Fig
.
7
.
Schematic
of
AII
Season
Traction
(AST)
system
.
INTEGRATED
SYSTEMS
EDC
POWER
SUPPLY
SOLENOID
RELAY
GROUND
CONTROL
POWER
SUPPLY
I'
1
ABS
PUMP
GROUND
CONTROLÍ
F
f
iJ
RELAY
INLET
(4X)
wxxuw
OUTLET
(4X)
-=-=--
AST
AST
INTAKE
IHYDRAULIC
-
=-
SWITCHING
=---
!
99001
!J
WHEEL
SPEED
X
4
DME
II
000001
-
f
1
UNIT
AGS
IKE
&
DMEI
PARK
BREVE
771
SWITCH
M
ALTERNATOR
AUXILIARY
THROTTLE
r
`
INDICATOR
POSITION
MOTOR
(ADS)
ABSPUMP
DIAGNOSIS
RELAY
lu~~~b
0013027
Page 298 of 759
340-
8
BRAKES
Fig
.
10
.
Brake
fluid
linesat
master
cylinder
(arrows)
.
6
.
If
fluid
reservoir
was
removed,
install
it
carefully
using
new
sealing
grommets
.
7
.
Mount
master
cylinder
to
brake
booster
using
a
new
0-
ring
and
new
self-locking
nuts
.
CAUTION-
Use
cave
not
to
over-torque
the
master
cylinder
mounting
nuts
.
This
could
damage
the
brake
booster
and
prevent
proper
vacuum
build-up
.
0012164
8
.
Connect
all
brake
fluid
lines
.
Connect
hydraulic
clutch
hose
to
brake
fluid
reservoir
.
9
.
Reconnect
fluid
leve¡
sender,
and
bleed
entire
brake
systemas
described
earlier
.
BRAKE
BOOSTER
BRAKE
BOOSTER
The
brake
booster
is
mounted
to
the
bulkhead
on
the
driver
sideofthe
engine
compartment,
directly
behind
the
brake
master
cylinder
.
See
Fig
.
11
.
0015225
Fig
.
11
.
Brake
booster
(arrow)
.
A
is
vacuum
hose
from
intake
mani-
fold
.
B
is
one-way
valve
.
Intake
manifold
vacuum
acts
ona
large
diaphragm
in
the
brake
booster
to
reducebrake
pedal
effort
.
Brake
booster,
removing
and
installing
1
.
Disconnect
negative
(-)
cable
from
battery
.
CAUTION-
Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
vi¡¡
.
Tightening
Torque
"
Brake
master
cylinder
to
2
.
Using
a
clean
syringe,
empty
brake
(luid
reservoir
.
brake
booster
.....
..
.
..
.........
26
Nm
(18
ft-Ib)
WARNING-
"
Brake
fluid
hose
to
caliper
....
17-19
Nm
(13-14
ft-Ib)
Brake
fluid
is
highly
corroslve
and
dangerous
to
the
environment
.
Dispose
of
it
properly
.
3
.
Remove
brake
fluid
level
sender
connector
from
reser-
voir
cap
.
4
.
Disconnectbrake
fluid
lines
from
master
cylinder
.
Plug
openings
.
5
.
Disconnect
engine
vacuum
hose
from
brake
booster
.