1994 BMW M3 ignition

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



-



-

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

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

160
Fuel
Tank
and
Fuel
Pump

GENERAL
.
.
.
.
.
.
...........
.
....
.
.
.
.
.
.
160-1



Operating
fuel
pump
for
tests
.
.
.
.
.
.
.......
.160-6

Fuel
Pump
Electrical
Tests
.
.
.
.
.
.
.
...
.
.
.
.
.
160-7

FUEL
TANK
AND
LINES
..
.
.
.
..........
160-2



Fuel
pump
electrical
circuit,
testing.
...
.
.
.
.
.
160-7

Fuel
tank,
draining
..
.
.
.
.
.
.
.
.
.
..........
160-2



Fuel
pump
power
consumption,
testing
.
.
.
.
.
.
160-7

Fuel
tank,
removing
and
installing
.........
160-3



Fuel
Delivery
Tests
....
.
.
.
...
.
.....
.
.
.
..
160-8

Fuel
Tank
Evaporative
Control
System
.....
160-4



Relieving
fuel
pressure
and
connecting

fuel
pressure
gauge
..
.
...........
.
.
.
..
160-8

FUEL
LEVEL
SENDERS
.
.
.
.
.
.......
.
.
.
160-4



System
pressure,
testing
.................
160-9

Fuel
level
senders,
testing
.
.
.
.
.
.......
.
.
.
160-5



Fuel
delivery
volume,
testing
.............
160-10

Fuel
leve¡
sender
and
fuel
pump
(right
side),
emoving
and
installing
.
.
.
.
.
.
160-5



TABLES

Fuel
leve¡
sender
(left
side),



a
.
FuelLeve¡
Sender
Resistances
...........
.
.
..
.160-5

removing
and
installing
.........
.
.
.
.
.
.
.
160-6



b
.
Fuel
Pump
Current
...
.................
..
...
160-8

c
.
Fuel
Pressure
Specifications
..............
.
..
160-10

FUEL
PUMP
.
.
.
................
.
.
.
.
.
.
.
160-6



d
.
Fuel
Pump
Delivery
Specifications
.........
.
..
160-10

Fuel
Pump
Fuse
and
Relay
.
.
.
....
.
.
.
.
.
.
.
160-6

GENERAL

This
repair
group
covers
service
information
specifically
for



The
cautions
and
warnings
on
this
page
should
beob
the
fuel
supply
system
.
Information
on
the
fue¡
injection
sys-



served
when
servicing
the
fuel
system
.
tem
is
covered
in
130
Fuel
Injection
.

NOTE-

Fue¡
filter
replacement
is
covered
in
020
Maintenance
Program
.

WARNING
-

"
The
fuel
system
is
designed
to
retain
pressure
even
when
the
ignition
isoff
.
When
working
with
the
fuel
system,
loosen
the
fuel
lines
slowly
toal-
low
residual
fuel
pressure
to
dissipate
gradually
.
Avoid
spraying
fuel
.

"
Before
beginning
any
work
on
the
fuel
system,
place
a
tire
extinguisher
in
the
vicinity
of
the
work
area
.

"
Fuel
is
highly
flammable
.
When
working
around
fuel,
do
not
disconnect
any
wires
that
could
cause
electrical
sparks
.
Do
not
smoke
or
work
near
heaters
or
other
tire
hazards
.

"
Always
unscrew
the
fuel
tank
cap
to
release
pres-
sure
in
the
tank
before
working
on
the
tank
or
fines
.

"
Do
not
use
a
work
light
near
any
fuel
.
Fuel
may
spray
onto
the
hot
bulb
causing
a
tire
.

"
Make
sure
the
work
area
is
properly
ventifated
.

FUEL
TANK
AND
FUEL
PUMP



160-1

CAUTION-

"
Prior
to
disconnecting
the
battery,
read
the
bat-tery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
viü
.

"
Before
making
any
electrical
tests
with
the
ignition
tumed
on,
disable
the
ignition
system
as
de-
scribed
in
120
Ignition
System
.
Be
sure
the
bat-tery
is
disconnected
when
replacing
components
.

"
To
prevent
damage
to
the
ignition
system
or
the
electronic
fuel
system
components,
including
the
control
unit,
aiways
connect
and
disconnect
wires
and
test
equipment
with
the
ignition
off
.

"
Cleanliness
is
essential
when
working
with
the
fuel
system
.
Thoroughly
clean
the
fuel
fine
unionsbefore
disconnecting
any
of
the
fines
.

"
Use
only
clean
tools
.
Keep
removed
parts
clean
and
sealed
or
covered
with
a
clean,
lint-free
cloth,
especially
if
completion
of
the
repair
is
delayed
.

"
Do
not
move
the
car
while
the
fuel
system
is
open
.

"
Avoid
using
high
pressure
compressed
air
to
blow
out
fines
and
componente
.
High
pressure
can
rupture
infernal
seals
and
gaskets
.

"
Always
replace
seals
and
O-rings
.

GENERAL

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
.

170-
4



RADIATOR
AND
COOLING
SYSTEM
A
quick
testat
the
coolant
temperature
gauge
sender
can



The
auxiliary
cooling
fan
comes
on
when
coolant
tempera

determine
if
the
gauge
is
functioning
correctly
.



ture
exceeds
a
predetermined
leve¡
or
whenever
the
air
condi-

tioning
is
on
.
A
dual-range
temperature
switch
for
cooling
fan
lf
the
gauge
needie
remains
at
the
rest
position
with
theen-



control
is
mounted
on
the
right
side
of
the
radiator
.
See
Fig
.
3
.
gine
warm,
remove
the
harness
connector
from
the
sender
and
jumper
the
correct
terminals
in
the
connector
to
simulate
a
high
engine
temperature
.
See
Table
a
.
Turn
the
ignition
on
.

If
the
gauge
needle
moves
upward,
the
sender
is
faulty
.
If
the

gauge
does
not
respond,
the
wiring
to
the
gauge
is
broken
(open
circuit)
or
the
gauge
itselfis
faulty
.

WARNING
-

1996
and
laten
models
are
OBD
11
compliant
.
Dis-
connecting
electrical
connectors
wíth
the
ignition
turned
on
may
set
fault
codes
in
the
ECM
.
It
is
rec-
ommended
that
you
leave
the
diagnosis
of
faults
in
the
coolant
temperature
sensorsystem
to
the
BMW
dealer
service
department
which
has
specialized
OBD
11
scan
tool
equipment
.

If
the
gauge
needle
reads
too
high
when
the
engine
is
cold,
remove
the
harness
connector
from
the
sender
.
Turn
the
igni-

tion
on
.
lf
the
gauge
needle
position
does
not
change,
the
wir-

ing
or
the
gauge
is
shorted
to
ground
.
If
the
gauge
needle

drops,
the
sender
is
faulty
and
should
be
replaced
.
When
re-

placing
a
faulty
coolant
temperature
sender,
the
gasket
ring
on
the
sender
should
also
be
replaced
.

Tightening
Torque

"
Temperature
gauge
sender
to
engine
18
Nm
(13
ft-Ib)

Cooling
fan,
testing

NOTE-

OnM44
engines
with
manual
transmission,
the
primary
electric
cooling
fan
is
mounted
on
the
engine
side
of
the
radiator
and
is
controlled
by
the
engine
control
module
(ECM)
.
Troubleshooting
thiscircuit
should
be
left
to
an
authorized
BMW
dealer
with
the
proper
diagnostic
equipment

An
otherwise
sound
cooling
system
may
still
overheat,
par-
ticularly
with
prolonged
idling,
due
to
a
failure
of
the
coolíng

fan(s)
.

The
belt-driven
cooling
fan
is
controlled
by
a
temperature
dependent
viscous
clutch
.
A
failed
fan
clutch
may
affect
air
flow
through
the
radiator
resulting
in
overheating
orpossibly
overcooling
.
Speed

Low
sp
High
s

With
the
engine
off,
check
thefan
clutch
by
spinning
thefan
.



eed
The
fan
should
spin
on
the
clutch
with
some
resistance
.



peed
Check
for
signs
of
leaking
fluid
from
the
clutch
.
If
thefan
free-
wheels
with
no
resistance,
cannot
be
tu
rned
by
hand,
or
there
are
signs
of
oil
leakage,
the
clutch
should
be
replaced
.

TROUBLESHOOTING

Fig
.
3
.



Radiatorcooling
fan
temperature
switch
(arrow)
.

WARNING
-

"
Use
caution
when
testing
the
electric
cooling
fan(s)
and
coolant
temperature
switch
.
Keep
hands
and
wires
clear
of
thefan
blades
.
The
cool-
ing
fan(s)
can
run
any
time
the
ignition
is
ON
.

"
For
greatest
safety,
coolíng
fan
and
coolant
tem-perature
switch
tests
shouldbe
performed
on
acoldengine
with
the
air
conditioning
off
.

Table
b
.
Auxiliary
Cooling
Fan
Switching

Temperatures

Switching
temperature
196°F(91°C)
210°F(99°C)

0012506

If
a
faulty
thermostat,
trapped
air,
or
a
restriction
in
the
sys-
tem
is
not
allowing
the
coolant
to
circulate
through
the
radia-
tor,
the
temperature
switch
will
not
close
and
the
auxiliary
cooling
fan
will
not
run
.
Before
making
the
tests
described
be-
low,
make
sure
the
thermostat
is
operating
correctly
as
de-
scribed
earlier
.
The
normal
switching
temperatures
for
the

dual
-speed
switch
are
listed
in
Table
b
.

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

170-6



RADIATOR
AND
COOLING
SYSTEM

Fig
.
6
.



Radiator
drain
plug
(arrow)
.

WARNING
-

Coolant
is
poisonous
.
Itis
especially
lethal
to
pets
.

Cleanup
spills
immediately
and
rinse
the
area
with

water
.

NOTE
-

The
block
drain
plug
is
located
on
the
exhaust
side
of
the
engine,
near
the
reas
of
the
engine
.

4
.
Reinstall
radiator
and
engine
block
drain
plugsusing

new
sealing
washers
.
Leave
heater
controis
on
full

warm
.

5
.
Using
a
coolantmixture
of
50%
antifreeze
and
50%
dis-

tilled
water,
fill
system
slowly
On
radiator
with
integral

expansion
tank,
bleed
cooling
system
as
described
be-

low
.

NOTE-

"
Tap
water
may
cause
corrosion
of
radiator,
engine
and
coolant
hoses
.

"
Coolant
can
often
be
reused
provided
itis
clean
and
less
than
twoyears
old
.
Do
not
reuse
coolant
when
re-
placing
damaged
engine
parts
.
Contaminated
coolant
may
damage
the
engine
or
cooling
system
.

Tabled
.
Cooling
System
Capacities

Engine



j
Capacity

4-cylinder



1
6
.5
liters
(6.9
qt)

6-cylinder
M50/M52



10
liters
(10
.6
qt)
S50US/S52US



10
.5
liters
(11
.1
qt)

COOLING
SYSTEM
SERVICE

Tightehing
Torques

"
Radiator
drain
plug
to
radiator
...
2-3
Nm
(18-27
in-lb)

"
Engine
block
drain
plug
to
block



.
.
..
25
Nm
(18
ft-Ib)

Cooling
system,
bleeding

(radiator
with
integral
expansion
tank)

NOTE
-

On
radiators
with
a
separate
expansion
tank,
ableed

screw
is
not
provided
.
The
cooling
system
with
sepa-

rate
expansion
tank
is
self
bleeding
via
the
vent
hose

on
the
expansion
tank
.

Air
maybecome
trapped
in
the
system
during
filling
.

Trapped
air
can
prevent
proper
coolant
circulation
.
Whenever

the
coolant
is
drained
and
filled,
the
system
should
be
bled
of

trapped
air
.

1
.
With
engine
cold,
add
coolant
to
expansion
tank
until

level
reaches
COLD
(KALT)
mark
on
tank
.

2
.
Loosen
bleed
screw
on
radiator
expansion
tank
.
See

Fig
.
7
.

0011976

Fig
.
7
.



Cooling
system
bleed
screwon
radiator
(arrow)
.
Note
cold
level
mark
on
expansion
tank
.

3
.
M3
models
:
Loosen
bleed
screw
on
thermostathous-

ing
.

4
.
Set
temperature
controls
in
passenger
compartment
to

fui¡
warm
and
turn
ignition
on
position
(do
not
start
en-

gine)
.