1994 BMW M3 coolant

Table
f
.
Engine
Coolant
TemperatureSensor
or

Intake
Air
TemperatureSensor
Test
Values

(DME
3
.113
.3
.1)

Test
temperatures



Resistance
(k
ohms)

14±
2°F
(-10
±
1'C)



7-11
.6

68±
2°F
(20
±
1'C)



2
.1
-2
.9

17612°F
(80
t
V
C)



0
.27-0
.40

NOTE

The
test
values
listed
represent
only
three
test
points
from
a
continuous
resistance
NTC
sensor
.
Check
the
full
linear
response
to
increasing
temperatures
as
the
engine
warms
up
.

3
.
If
ECT
sensor
fails
these
tests,
it
is
faulty
and
should
be

replaced
.
If
no
faults
are
found,
reconnect
electrical

harness
.

WARNING
-

Do
not
replace
the
ECT
sensor
unless
the
engine
is

cold
.
Hot
coolant
can
scald
.

NOTE-

Use
"



a
new
copper
sealing
washer
when
installing
sensor
.
Replace
any
lost
coolant
.

Tightening
Torque

"
Engine
coolant
temperature
sensor

to
cylinder
head
.........
..
.
..
...
13
Nm
(10
ft-lb)

Intake
air
temperature
(IAT)
sensor,

testing
and
replacing

The
intake
air
temperature
(IAT)
sensor
signal
is
usedasa

correction
factor
for
fuel
injection
and
ignition
timing
.
Thissen-

sor
is
mounted
in
the
intake
manifold
behind
the
throttle
posi-

tion
switch
.
See
Fig
.
28
.

Check
TPS
function
by
disconnecting
theharnessconnec-
1
.
Check
that
ECM
reference
voltage
is
reaching
IAT
sen-



tor
and
testing
continuity
across
the
terminalswhile
changing
sor
:



the
throttle
position
.
Resistance
test
values
are
listed
below
.
If

"
Disconnect
IAT
sensor
harness
connector
.



the
resuits
are
incorrect,
replace
the
throttle
position
sensor
.

"
Turn
ignition
keyon
.



See
Fig
.
29
.

"
Check
for
5
volts
between
supply
voltage
wire
of
har-

ness
connector
and
ground
.
NOTE-
"
Turn
ignition
key
off
.
The
throttle
position
sensor
is
not
adjustable
.
If
test
re-
sults
are
incorrect,
the
sensor
should
be
replaced
.

IAT
Sensor
Supply
Voltage

"
M50/S50US
engines
.
........
grey
wire
and
ground

FUEL
INJECTION



130-19

Fig
.
28
.
Intake
air
temperature
sensor
location
on
M50/S50US
engine
(arrow)
.

If
voltage
is
not
present
or
incorrect,
check
wiring
from
ECM

and
check
reference
voltage
signal
at
ECM
(pin
77)
.
See
Ta-

ble
i
or
Table
j
.

2
.
Check
IAT
sensor
resistance
:

"
With
harness
connector
disconnected,
check
resis-

tance
acrosssensor
terminals
.
Compare
tests
resuits
to
values
in
Table
f
given
earlier
.

"
If
IAT
sensor
fafs
thistest
it
is
faulty
and
should
be
re-

placed
.

3
.
If
no
faults
are
found,
reconnect
electrical
harness
.

Throttle
position
sensor
(TPS),

testing
and
replacing

The
throttle
position
sensor
(TPS)
is
mounted
on
the
side
of

the
throttle
housing
and
is
directly
connected
to
the
throttle

valve
shaft
.
The
ECM
sends
a
voltage
signal
to
the
potentiom-

eter-type
sensor
and
monitors
the
voltage
that
comes
back
.

BOSCH
DME
M3
.
1
AND
M32
.1
COMPONENT
TESTS
AND
REPAIRS

130-
2
2



FUEL
INJECTION

Mass
air
flow
sensor,
replacing

1
.
Disconnect
harness
connector
and
intake
air
bootfrom

air
flow
sensor
.
See
Fig
.
32
.

Fig
.
32
.
To
detach
air
flow
sensor,
disconnect
harness
connector
(A)
;



3
.
Installation
is
reverse
of
removal
.
unclip
retainíng
clips
to
aír
filter
housing
(B)
;
andremove
large
hose
clamp
at
air
intake
bellows
(C)
.
M44
engine
with
traction



"
Use
a
new
copper
sealing
washer
when
installing
sen-

control
shown
.



sor
.
"
Replace
any
lost
coolant
.

2
.
Detachtwo
large
clipsat
air
filter
housing
and
work
air

flow
sensor
out
of
rubber
seal
in
filter
housing
.
Tightening
Torque

3
.
Installation
is
reverse
of
removal
.



"
Engine
coolant
temperature

"
For
ease
of
installation,
lubricate
large
rubber
seal
in



to
cylinder
head
.............
.
..
.
13
Nm
(10
ft-Ib)

air
filter
housing
with
silicone
lubricant
or
equivalent
.
"
No
adjustment
to
air
flow
sensor
is
possible
.
"
Carefully
check
that
all
hoses
and
seals
are
seated



Intake
air
temperature
(IAT)
sensor,

properly
.



replacing

Engine
coolant
temperature
(ECT)
sensor,

replacing

The
engine
coolant
temperature
(ECT)sensor
is
a
dual
temperature
sensor
.
One
circuít
provides
coolant
temperature

information
to
the
ECM
while
the
other
circuít
provides
coolant
temperature
information
to
the
instrument
cluster
.

WARNING
-

Do
not
replace
the
ECT
sensor
unless
the
engine
is
cold
.
Hot
coolant
can
scald
.

1
.
Disconnect
harness
connector
from
ECT
sensor
.
See
Fig
.
33
.

2
.
Unscrew
temperature
sensorfrom
cylinder
head
and
remove

BOSCH
DME
M5
.2
COMPONENT
REPLACEMENT

U1111
bis4a

Fig
.
33
.
M44
engine
coolant
temperature
(ECT)
sensor
located
above

oil
filter
(arrow)
.

The
intake
air
temperature
(IAT)
sensoron
cars
with
M44

engine
is
mounted
in
thetop
section
of
the
intake
air
filter

housing
.
See
Fig
.
34
.

1
.
Remove
electrical
harness
connector
from
IAT
sensor
.

2
.
Unclip
temperature
sensor
and
remove
from
air
filter

housing
.

3
.
Installation
is
reverse
of
removal
.

Throttle
position
sensor
(TPS),
replacing

The
throttle
position
sensor
is
located
on
the
side
of
the
throttle
housing
.
See
Fig
.
35
.

1
.
Unplug
harness
connector
from
sensor
.

130-24



FUEL
INJECTION

Jo
'0

o_A

í1
RELAY

..
.
.

CAMSHAFT
POSITION
SENSOR

'
.
~'



~
:UhI~IIUH~W~`bY~7~d~t~II7

.
.
.
,

1111111
~ilf

ASC

TERMINAL
15

MEMORY
POWER

CRANKSHAFT
POSITION
qtcMSENSOR

THROTTLE
POSITION

ENGINE
COOLANT
TEMP

FUELTANK
PRESSURE
SENSOR

S-EML
S-MSR

S-ASC

VEHICLE
SPEED

LOW
FUEL
LEVEL

A/C
SWITCH
ON
(AC)
E36
IHKA



COMPRESSOR
"ON"
SIGNAL
(KO)

INDIVIDUAL
SERIAL
NUMBER

SIEMENS
MS
41
.
1
COMPONENT
REPLACEMENT

FUEL
PUMP
RELAY
CONTROL
AUX
GROUND
P

MAIN
GROUND
AC
COMPRESSOR
RELAY
CONTROL



~®

SECONDARY
AIR
INJECTION
AIR
PUMP
RELAY
CONTROL
-
M

PRE
CAT



POST
CAT
m
nXYGEN
SENSOR

ys
U
~
4



,
HEATING

FUELINJECTOR
CONTROL
(

MS
41
.1



(

MS

PURGE
CONTROL
VALVE



//



PURGE
'
CANISTERSHUT-OFF
VALVE

ECM
RELAY
CONTROL

IGNITION
COILS
CONTROL

1
ASC

o
ayi

THROTTLE
POTENTIOMETER
POWER

,

al
;
..
i

r71a
.

"a
fn7111,
/



r

Fig
.
36
.
Siemens
MS
41
.1
OBD
II
engine
management
system
usedon
M52
engine
.
Bosch
M5
.2
systemusedon
M44
engine
is
similar
.

Mass
air
flow
sensor,
replacing

1
.
Disconnect
harness
connector
and
intake
air
boots

from
air
flow
sensor
.
See
Fig
.
37
.

Fig
.
37
.
Mass
air
flow
sensor
(arrow)
on
M52
engine
.

2
.
Installation
is
reverse
of
removal
.

"
No
adjustment
to
aír
flow
sensor
is
possible
.

"
Check
intake
hoses
for
cracks
and
vacuum
leaks
.

Engine
coolant
temperature(ECT)
sensor,

replacing

The
ECT
sensor
is
a
dual
temperature
sensor
.
One
circuit

provides
coolant
temperature
information
to
the
ECM
while

the
other
circuit
provides
coolant
temperature
information
to

the
instrument
cluster
.

1
.
Remove
left-side
top
engine
cover
.

4
.
Remove
sensor
.

5
.
Installation
is
reverse
of
removal
.

"
Replace
any
lost
coolant
.

0012703

"
Use
a
new
copper
sealing
washer
when
installing
new

Tightening
Torque

"
Engine
coolant
temperature

to
cylinder
head
.....
..
.
...
......
13
Nm
(10
ft-Ib)

FUEL
INJECTION



130-
25

0012704b

Fig
.
38
.
M52
engine
:
Engine
coolant
temperature
(ECT)
sensor
(A)
is
located
beneath
top
engine
cover
(8)
and
crankcase
vent

hose
(C)
.

Intake
air
temperature
(IAT)
sensor,

replacing

The
intake
air
temperature
(IAT)
sensor
for
the
M52/S52US

engine
is
mounted
on
the
bottom
of
the
intake
manifold
.
See
Fig
.

39
.

2
.
Unclip
crankcase
venting
hose
from
cylinder
head
cov-

er
.
See
Fig
.
38
.



Fig
.
39
.
M52/S52US
engine
:
Intake
air
temperaturesensor
location
in

bottom
of
intake
manifold(arrow)
.
Throttle
housing
shown
re

3
.
Under
intake
manifold,
disconnect
harness
connector



moved
.

fromsensor
.

1
.
Disconnect
intake
air
bootfrom
throttle
housing
.
Unbolt

throttle
housing
and
¡ay
aside
.
(It
is
not
necessary
to

disconnect
throttle
cable
or
electrical
harnessconnec-

tors
from
throttle
housing
.)

sensor
.



2
.
Remove
electrical
harness
connector
from
IAT
sensor
.

3
.
Unclip
temperature
sensor
and
remove
from
intake

manifold
.

4
.
Installation
is
reverse
of
removal
.
Use
a
new
gasket
at

the
throttle
housing
.

SIEMENS
MS
41
.1
COMPONENT
REPLACEMENT

130-
2
8



FUEL
INJECTION

Tableh
.
ECM
Pin
Assignment-Bosch
DME
M1
.7

Pin
Signal
Componenttfunction



Signal

1



Output



Fuel
pump
relay
control



Fuel
pump
relay,
terminal
85

2



Not
used

3



Output



Cyl
.
2
and
cyl
.
4
fuel
injection
valve
control



Cyl
.
2
and
cyl
.
4
fuel
injection
valves
4



Not
used

5



Not
used

6



Ground



Ground,
fuel
injection
valveoutputstages



Ground
point

7



Not
used

8



Output



"Check
engine"
indicator
control



Instrument
cluster

9



Not
used

10



Not
used

11



Output



DKV
potentiometer
signal



Transmission
control
module
(EGS)

12



Input



Throttleposition
sensor



Throttleposition
Signal

13



Not
used

14



Input



Volume
air
flow
sensor



Volume
air
flow
sensor
(signal
ground)

15



Input



Cyl
.
1-2
knock
sensor



Cyl
.
1-2
knock
sensor

16



Input



Camshaft
position
sensor
(cylinder
identification)



Camshaft
position
sensor
(cylinder
identification)

17



Output



ti
measurement
signal
(fuel
consumption)



Instrument
cluster

18



Output



Intakeair
resonance
changeover
valve
(DISA)



Intake
air
resonance
changeover
valve
19



-



Not
used

20



Not
used

21



Not
used

22



Not
used

23



Not
used

24



Output



Cyl
.
3
ignition
coil
control



Cyl
.
3
ignition
coil

25



Output



Cyl
.
1
ignition
coil
control



Cyl
.
1
ignition
coil

26



Input



Battery
voltage



B
+junction
point

27



Output



Engine
control
module
relay
control



Engine
control
module
relay,
terminal
85
28



Ground



Ground
for
electronics
and
shielding
of
sensors



Ground
point

29



Output



Idle
speed
control
valve
control



Idle
speed
control
valve

30



Not
used

31



Not
used

32



Output



Cyl
.
1
and
cyl
.
3
fuel
injection
valve
control



Cyl
.
1
and
cyl
.
3
fuel
injection
valves

33



Not
used
34



Ground



Ground,
output
stages
(except
for
ignition
and
fuel



Ground
point
injection
valves)

35



Not
used

36



Output



Evaporative
emissionvalve
control



Evaporative
emission
valve

37



Output



Oxygen
sensor
heater
control



Oxygen
sensor
relay,
terminal
85
38



Not
used
39



Not
used
40



I
Not
used

41



I
Input



,
Volume
Air
Flow
sensor



Volume
air
flow
sensor
(voltage
varies
with
engine
load)

42



1
Input



1
Cyl
.
3-4
knock
sensor



1
Cyl
.
3-4
knock
sensor

43



Ground



Ground
for
sensors



Engine
coolant
temperature
sensor,
cyl
.
1-2
knock
sensor,
cyl
.
3-4
knock
sensor,
and
throttle
position
sensor

44



1
Input



1
Camshaft
position
sensor
(cylinder
identification)



1
Camshaft
position
sensor
(cylinder
identification)

ECM
PIN
ASSIGNMENTS

Tableh
.
ECM
Pin
Assignment--Bosch
DME
M1
.7

Pin



1
Signal



1
Component/function



1
Signal

45
Notused

46
Notused

47
Notused

48



Output



A/C
compressor
cut-out



Compressor
control
relay,
terminal
85
49
Notused

50
Notused

51



Output



Cyl
.
4
ignition
coil
control



Cyl
.
4
ignition
coil

52



Output



Cyl
.
2
ignition
coil
control



Cyl
.
2
ignition
coil

53



Not
used
54



Input



Battery
voltage
from
engine
control
module



Engine
control
module
relay,
terminal
87a

55



Ground



Ground,
ignition



Ground
point

56



Input



Ignition
switch,
terminal
15



Ignition
switch,
terminal
15
57
Notused

58



Not
used

59



Output



Throttleposition
sensor
and
volume
air
flow
sensor



Reference
voltage
(5
VDC)

60



Input



Programming
voltage



Data
link
connector

61
Notused

62
Notused

63
Notused

64



Input



Ignition
timing
intervention



Transmission
control
module
(EGS)

65



Input



Drive
range
P/N



Automatic
transmission
range
switch

66
Notused

67



Input



Crankshaft
position
RPM
sensor



Crankshaft
position
RPM
sensor

68



Input



Crankshaft
position
RPM
sensor



Crankshaft
position
RPM
sensor

69
Notused

70



Input



Oxygen
sensor
signal



Heated
oxygen
sensor

71



Ground



Oxygen
sensor
signal
ground



Heated
oxygen
sensor

72
Notused

73



Input



Vehicle
speed
signal



Instrument
cluster

74



Output



Engine
speed
signal



Instrument
cluster

75



Not
used
76



Input



Volume
air
flow
sensor



Volume
air
flow
sensor

77



Input



Intake
air
temperature
sensor
(IAT)



Intake
air
temperature
sensor
(IAT)

78



Input



Engine
coolant
temperature



Engine
coolant
temperature
sensor

79
Notused

80



Not
used

81



Input



Drive-away
protection
signal
(code)



On-boardcomputer

82



Not
used
83
Notused

84



Not
used
85



Input



A/C
pressure



Pressure
switch

86



Input



A/C
switch



Integrated
climate
regulation
control
module

87



Output



RxD
diagnosisdata
line



Data
link
connector

88



Output-Input



TxD
diagnosisdata
line



l
Data
link
connector

FUEL
INJECTION



130-
2
9

ECM
PIN
ASSIGNMENTS

Table
i
.
ECM
Pin
Assignment-Bosch
DME
M3
.1

Pin



Signal



Component/function



2

ignal

FUEL
INJECTION



130-
3
1

45
vacant
-

46
vacant
-



-

47
vacant
-



-

48



output



A/C
compressor
control



A/C
compressor
disabled
via
compressor
control
relay

49
vacant
-



-

50



output



Ignition
control
(terminal
1),cyl
.
n
o
.
4



Primary
signal,
ignition
coil
cyl
.
n
o
.
4

51



output



Ignition
control
(terminal
1),cyl
.
n
o
.
6



Primary
signal,
ignition
coil
cyl
.
no
.
6

52



output



Ignition
control
(terminal
1),cyl
.
n
o
.
5



Primary
signal,
ignitioncoil
cyl
.
no
.
5

53
vacant



-

54



input



Power
supply



Battery
voltage
(+)
from
main
relay
terminal
87
55



ground



Ground



Ground
for
ignition
control

56



input



Power
supply
(terminal
15)



Batteryvoltage
(+)
with
key
on
or
engine
running

57
vacant
-



-

58
vacant
-



-

59



output



Throttleposition
sensor



Throttleposition
sensorsupply
voltage
(5
VDC)

60



input



Data
link
connector



Programming
voltage

61
vacant
-



-

62
vacant
-



-

63
vacant
-



-

64



input



Ignition
timing
intervention



from
A/T
control
module
(only
active
during
gearshift)

65



input



Automatic
transmission
(A/T)
range
switch



Transmission
park
or
neutral
signal

66
vacant
-



-

67



input



Engine
speed/crankshaft
position
sensor



Crankshaft
position/rpm
(voltage
(VAC)
between
pins
67
and
68)

68



input



Engine
speed/crankshaft
position
sensor



Crankshaft
position/rpm
(voltage
(VAC)
between
pins
67
and
68)

69
vacant
-



-

70



input



Oxygen
sensor



Oxygen
sensor
signal
(0-1
VDC
fluctuating
with
engine
running)

71



ground



Oxygen
sensor



Oxygen
sensor
signal
ground

72
vacant
-



-

73



input



Road
speed



Road
speed
signal
from
instrument
cluster

74



output



Engine
speed
(TD)



Engine
speed
(TD)
signalto
instrument
cluster

75
vacant
-



-

76
vacant
-



-

77



input



Intakeair
temperature
(IAT)
sensor



Intake
air
temperature
(0-5
V,
temperaturedependent)

78



input



Engine
coolant
temperature
(ECT)
sensor



Engine
coolant
temperature
(0-5V,
temperature
dependent)

79
vacant
-



-

80
vacant
-



-

81



input



On-boardcomputer



Drive-away
protection
enable

82
vacant
-



-

83
vacant
-



-

84
vacant
-



-

85



input



A/C
pressure
switch



From
Integrated
climate
control
module
via
A/C
pressure
switch

86



input



A/C
compressor
on



From
Integrated
climate
control
module
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

130-
3
2



FUEL
INJECTION

Pin



1
Signal



1
Component/function



1
Signal

1



output



Fuel
pump
relay
control



Fuel
pump
relay
switches
with
engine
running
or
cranking
(crankshaft
position
signal
must
be
present
for
relay
switchover)

2



output



Idle
speed
control
valve



Pulsed
ground-close
signal
(seealso
pin
29)

3



output



Fuel
ínjectorcontrol,
cyl
.
5



Pulsed
ground
(injection
pulsewidth
in
ms)
cyl
.
5
4



output



Fuel
injectorcontrol,
cyl
.
6



Pulsed
ground
(injection
pulsewidth
in
ms)
cyl
.
6
5



output



Fuel
injectorcontrol,
cyl
.
4



Pulsed
ground
(injection
pulsewidth
in
ms)
cyl
.
4
6



ground



Ground



Ground
for
fuel
injector
output
stage

7



output



Camshaft
actuator
(VANOS
solenoid)
control



Camshaft
actuator
(VANOS
solenoid)

8



output



Check
Engine



Instrument
cluster,
Check
Engine
lamp

9
vacant
-



-

10
vacant
-



-

11



output



Throttle
position



Throttle
angle
signal
to
A/T
control
module
12
vacant
-



-

13



input



Oxygen
sensor



Oxygen
sensor
signal
(0-1
VDC
fluctuating
with
engine
running)

14



input



Mass
air
flow
sensor



Mass
air
flow
sensor

15
ground
Ground



Ground

16



input



Crankshaft
position/rpm
sensor



Voltage
pulse
(VAC)
between
pin
16
and
43
(crank
position/rpm
sensor)

17



input



Camshaft
position
sensor



Halleffect
camshaft
sensor

18
vacant
-



-

19
vacant
-



-

20
vacant
-



-

21
vacant
-



-

22
vacant
-



-

23



output



Ignition
coil
control,
cyl
.
4



Ignition
coil
4

24



output



Ignition
coil
control,
cyl
.
6



Ignition
coil
6

25



output



Ignition
coil
control,
cyl
.
5



Ignition
coil
5

26



input



Power
supply
(terminal
30)



Battery
voltage(B+)
at
all
times

27



input



Main
relay
control



Main
relayactivation
(terminal
85)

28



ground



Ground



Ground
for
ECM
and
sensor
shielding

29



output



Idle
speed
control
valve



Pulsed
ground-open
signal
(seealsopin
2)

30
vacant
-



-

31



output



Fuel
injectorcontrol,
cyl
.
3



Injection
pulse
wicith
in
ms-cyl
.
3

32



output



Fuel
injectorcontrol,
cyl
.
2



Injection
pulse
wicith
in
ms-cyl
.
2

33



output



Fuel
injectorcontrol,
cyl
.
1



Injection
pulsewidth
in
ms-cyl
.
1

34



ground



Ground



Ground
for
remaining
output
stages

35
vacant
-



-

36



output



Evaporative
purge
valve
control

37
vacant
-



-

38



output



Oxygen
sensor
heater
relay
control



Oxygen
sensor
heater
relay
switchover
(terminal
85)

39
vacant
-



-

40



ground



Oxygen
sensor



Oxygen
sensor
signal
ground

41



input



Mass
air
flow
sensor



Mass
air
flow
voltage
signal

42



input



Vehicle
speed



Vehicle
speed
signal
from
instrument
cluster

43



input



Crankshaft
position/rpm
sensor



Voltage
pulse
(VAC)
between
pin16
and
43
44



ground



Ground



Ground
for
intake
air
temp
.
sensor,
engine
coolant
temp
.
sensor,
throttle
position
sensor

ECM
PIN
ASSIGNMENTS

Table
j
.
ECM
Pin
Assignment-Bosch
DME
M3
.3
.1