1998 BMW M3 Timing

GENERAL
.
........
.
...........
.
.
.
.
.
.
.
120-1



Camshaft
Position
(CMP)
Sensor
....
.
.
.
...
120-6

Disabling
Ignition
System
.
.
.
.
.....
.
.
.
.
.
.
.
120-2



Camshaft
position
(CMP)
sensor,
replacing

Warnings
and
Cautions
.
.
.
.
.
.
.....
.
.
.
.
.
.
.
120-2



(4-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
120-6

Camshaft
position
(CMP)
sensor,
replacing

IGNITION
SYSTEM
DIAGNOSTICS
.
.
.
.
.
.
120-3



(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
120-7
Basic
Troubleshooting
Principles
...
.
.
.
.
.
.
.
120-3



Knock
sensors,
replacing
.
.
...
.
.
.
.
.
.
.
.
.
.
.
.
120-7

Ignition
Firing
Order
.....
.
...
.
.
.
.....
.
.
.
.120-7

IGNITION
SYSTEM
SERVICE
.
.........
.
120-3

Checking
for
Spark
..
.
.
.
.
.
.
.
.
.
.......
.
.
.
120-3

Ignition
coil,
testing
and
replacing

(4-cylinder
engine)
.
.
.
.
.
.
.
.
.
.
.........
.
120-3

Ignition
coil,
testing
and
replacing

(6-cylinder
engine)
.........
.
..........
120-4

Crankshaft
Positionlrpm
Sensor
.......
.
...
120-5

Crankshaft
position/rpm
sensor,
testing
and

replacing
(front
mounted)
.........
.
.
.
.
.
.
120-6

Crankshaft
position/rpm
sensor,replacing

(rear
mounted)
.....
.
.....
.
.....
.
.
.
.
.
.
120-6

GENERAL



Troubleshooting
and
testing
of
the
engine
management

system
should
be
carried
out
using
the
BMW
specialized
ser

This
repair
group
covers
repair
andcomponent
replace-



vice
tester
(scan
tool)
.

ment
information
for
the
ignition
system
.
All
engines
use
a
distributorless
ignition
system
with
indívid-

ual
ignitioncoils
for
each
cylinder
.
There
is
no
distributor
cap

NOTE-



or
ignition
rotor
.
Each
coil
can
be
selectively
controlled
by
the

"
Spark
plug
replacement
is
covered
in
020
Mainte-



engine
control
module
on
a
cylinder-by-cylinder
basis
.
On
later

nance
Program
.



systems,
knock
sensors
are
used
to
monitor
and
control
igni-

"
For
fuel
related
troubleshooting
and
testing,
see
130



tion
knock
(ping)
and
adjusttiming
accordingly
.

Fuel
lnjection
.
Ignition
timing
is
electronically
controlled
and
not
adjust-

All
engines
covered
by
this
manual
use
an
advanced
en-



able
.
The
engine
control
module
(ECM)
usesengine
load,
en-

gine
management
system
.
The
engine
management
system



gine
speed,
coolant
temperature,
and
intake
air
temperature

incorporates
on-board
diagnostics,
fuel
injection,
ignition
and



as
the
basic
inputs
for
timing
control
.
Knock
detection
is
also

other
advanced
engine
control
functions
.



an
input
to
the
control
module,
where
applicable
.

Table
a
.
Engine
Management
System
Variants

Engine
code



1
System

4-cylinder
M42
(1.8
I)



Bosch
DME
Ml
.7
M44
(1
.9
I)



Bosch
DME
M5
.2
(OBD
II)

6-cylinder
M50
1992
(2.5
I)



Bosch
DME
M8
.1
1993-1995
(2
.5
I)



Bosch
DME
M33
.1
M52
1996-1998
(2.8
I)



Siemens
MS
41
.1
(OBD
II)

1998
(2
.5
I)



Siemens
MS
41
.1
(013D
11)
S50US
(3.0
I)



Bosch
DME
M3
.3.1
S52US
(3.2
I)



Siemens
MS
41
.1
(OBD
II)

120
Ignition
System

IGNITION
SYSTEM



120-1

IGNITION
SYSTEM
SCHEMATICS
...
.
.
.
.120-7

TABLES

a
.
Engine
Management
System
Variants
......
120-1

b
.
Ignition
Coil
Resistance
(M42
engine)
......
120-4

c
.
Ignition
Coil
Resistance
(M44
engine)
......
120-4

d
.
Ignition
Coil
Resistance

(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.....
.
..
120-5

NOTE-

All
engines
coveredby
this
manual,
with
theexception

of
the
1992
M50,
incorporate
knocksensors
as
part
of

the
engine
management
system
.

The
initial
ignition
point
is
determined
by
the
crankshaft
po-

sition/rpm
sensor
during
cranking
.
Once
the
engine
is
run-

ning,
timing
is
continually
adjusted
based
on
operating

conditions
.
A
characteristic
ignition
map
is
shown
in
Fig
.
1
.
A

map
similar
to
the
one
shown
is
digitally
stored
in
the
engine

control
module
.

GENERAL

120-
6



IGNITION
SYSTEM

Crankshaft
position/rpm
sensor,

testing
and
replacing
(front
mounted)

1
.
Disconnect
sensor
harness
connector
.

2
.
Using
a
digital
multimeter,
check
resistance
between
terminals
1
and
2
in
connector
.
See
Fig
.
10
.

n1
n2n3

Fig
.
10
.
Crankshaft
position/rpm
sensorconnector
.

Crankshaft
positionlrpm
sensor
specifications

"
Coil
resistance
(approx
.)
terminais
1
and
2
....
.
..
...
....
1280
±
10%
ohms

"
Air
gap
(sensor
distance
from
toothed
wheel)
..
.
.
........
.1
.0
±
0
.3
mm
(0
.04
±
0
.01
in
.)

3
.
If
the
resistance
is
not
correct,
the
sensor
is
faulty
and
should
be
replaced
.

NOTE
-

When
installing
the
new
sensor,
be
sure
thewiring
Is
rerouted
in
the
same
orientation
.
Secure
the
sensor
us-
ing
new
wire
ties
.

Tightening
Torque

"
Crankshaft
position/rpm
sensor
to
mounting
bracket
.........
.
.
5
t
1
Nm
(62
t
9
in-lb)

Crankshaft
position/rpm
sensor,



4
.
Installation
is
reverse
of
removal
.
Use
a
new
O-ring
replacing
(rear
mounted)



when
installing
sensor
.
Be
sure
wiring
is
rerouted
in
same
orientation
.
1
.
Disconnect
sensor
harness
connector
.

6502AGN56

2
.
Locatesensor
on
rear
left
sideof
cylinder
block
.
Re-
move
sensormounting
bolt
and
remove
sensorfrom
cylinder
block
.

IGNITION
SYSTEM
SERVICE

3
.
Installation
is
reverse
of
removal
.
Use
a
new
O-ring

when
installing
sensor
.
Be
sure
wiring
is
rerouted
in
same
orientation
.
Secure
sensor
using
new
wire
ties
.

NOTE-

It
may
be
easier
to
remove
the
sensor
working
from
the
underside
of
the
vehicle
.

Camshaft
Position
(CMP)
Sensor

The
camshaft
position
(CMP)
sensor
is
usedby
the
engine
management
system
for
sequential
fuel
injection
and
knock
control
.

Camshaft
position
(CMP)
sensor,

replacing
(4-cylinder
engine)

1
.
Remove
CMP
sensorfromtop
timing
cover,
just
above
coolantthermostat
housing
.
See
Fig
.
11
.

Fig
.
11
.
Camshaft
position
sensor
mounting
bolt
(arrow)
.
M42
engine
shown
.

2
.
On
M42
engines
to
9/93
:
Disconnect
CMP
harness
plug
just
above
oil
filter
housing
.

3
.
On
M42
from9/93
and
all
M44
engines
:
Remove
upper
intake
manifold
as
described
in
113
Cylinder
Head
Re-
moval
and
Installation
.
Then
unplug
CMP
sensor
har-
ness
connector
below
manifold
.

Camshaft
position
(CMP)
sensor,

replacing
(6-cylinder
engine)

1
.
Remove
plastic
cover
from
above
fuel
injectors
.

2
.
Disconnect
harness
connector
from
VANOS
solenoid

and
unscrew
solenoid
from
VANOS
control
unit
.
Re-



"
Clean
contactsurface
on
engine
block
before
fnstall

move
oil
supply
line
from
VANOS
control
unit
.
See
117



ing
knock
sensors
.

Camshaft
Timing
Chain
.

3
.
Remove
camshaft
position
(CMP)
sensor
from
left
frontof

cylinder
head,
next
to
top
of
oil
filter
housing
.



"
Knock
sensor
to
cylinder
block
....
20
Nm
(15
ft
.
lbs
.)

4
.
Disconnect
CMP
sensor
harnessfrom
under
intake

manifold
.

5
.
Installation
is
reverse
of
removal
.
Use
a
new
O-ring

when
installing
sensor
.
Be
sure
wiring
is
rerouted
in

same
orientation
.

Tightening
Torques

"
CMP
sensor
to
cylinder
head
....
.
.
..
5
Nm
(3
.5
ft-Ib)

"
VANOS
oil
supply
pipe
to

VANOS
control
unit
...........
.
..
32
Nm
(24
ft-Ib)

"
VANOS
solenoid
to
VANOS

control
unit
...
.
.................
30
Nm
(22
ft-Ib)

Knock
sensors,
replacing

Knock
sensors
are
usedon
engines
with
Bosch
DME
M1
.7,

Bosch
DME
M3
.3
.1,
Bosch
DME
M5
.2,
and
Siemens
MS
41
.1

engine
management
systems
.
The
knocksensors
are
bolted
to
the
left
sideof
the
cylinder
block
and
monitor
the
combus-

tion
chamber
for
engine-damaging
knock
.
If
engine
knock
is

detected,
the
ignition
point
is
retarded
accordingly
via
the
en-

gine
control
module
.

CA
UTION-

"
Label
knock
sensorharness
connectors
before

disconnecting
them
.
The
connectors
must
not
be

interchanged
.
Engine
damage
may
result
if
the
sensors
are
monitoring
the
wrong
cytinders
.

"
Note
the
installed
angle
of
the
knock
sensoron
the

block
before
removing
it
.
Reinstall
the
sensor
in

the
same
position
.
Be
sure
to
usea
torque
wrench

when
tightening
the
sensormounting
bola

NOTE
-

"
On
M52
engines,
a
single
harness
connects
the
twosensors
to
the
main
harness
connector
.
The
shorter
cable
lead
fs
for
the
knock
sensor
for
cytinders
4,
5,
and
6
.

Tightening
Torque

IGNITION
SYSTEM



120-
7

0012730

Fig
.
12
.
Knock
sensor
mounting
bolt
on
front
left
side
of
cylinder

block
.

NOTE-

Knock
sensor
function
Is
monitoredby
the
On-Board
Diagnostic
system
.
If
a
knock
sensor
is
detected
to
be
faulty,
an
appropriatediagnostic
trouble
code
(DTC)
may
be
stored
in
memory
.
See
100
Engine-General
for
information
on
retrieving
DTCs
.

On
6-cylinder
engines,
the
knock
sensors
are
accessible
af-
ter
removing
the
intake
manifold
.
On
4-cylinder
engines,
the

upper
section
of
the
intake
manifold
should
be
removed
to
ac-

cess
the
sensors
.
See
Fig
.
12
.
NOTE-

Intakemanifold
removal
and
installation
procedures
are



"
Cylinder
no
.
1is
at
the
front
of
the
engine
.

covered
in
113
Cylinder
HeadRemoval
and
Installation
.

Ignition
Firing
Order

Ignition
Firing
Order

"
4-cylinder
engines
.....
..
...
.
..........
.1-3-4-2

"
6-cylinder
engines
...........
..
.
.
..
..
1-5-3-6-2-4

IGNITION
SYSTEM
SCHEMATICS

Fig
.
13
through
Fig
.
17
show
ignition
system
schematics

usedon
the
enginescoveredby
this
manual
.

IGNITION
SYSTEM
SCHEMATICS

130-2



FUEL
INJECTION

GENERAL

This
repair
group
covers
fuel
injection
system
component

testing
and
repair
.
Special
equipment
is
necessary
for
some

of
the
procedures
given
in
this
repair
group
.
If
you
do
not
have

the
equipment
required
to
do
the
job,
it
is
recommended
that

these
repairs
be
left
to
an
authorized
BMW
dealer
.
The
BMW

dealer
is
equipped
with
sophisticated
diagnostic
test
equip-

ment
that
is
capable
of
quicklypinpointing
hard-to-find
fuel
in-

jection
problems
.

NOTE-

"
Wiring
diagrams
for
the
engine
management
system,

can
be
found
at
the
rear
of
the
manual
under
Electri-
cal
Wiring
Diagrams
.

"
For
ignition
system
repairinformation,
see120
Igni-

tion
System
.

"
For
fuel
supply
system
testing
and
repair,
see160



The
engine
control
module
(ECM)
uses
electrical
signals

Fuel
Tank
and
Fuel
Pump
.



from
the
mass
air
flow
sensor,
the
air
and
coolant
temperature

sensors,
the
crankshaft
position/rpm
sensor,
the
knock
sen

Principies
Of
Operation



sors
and
the
oxygen
sensorsas
the
primary
inputs
to
electron-

ically
control
fuel
delivery
and
ignition
timing
.

There
are
five
versions
of
engine
management
systems

usedon
the
E36
cars
.
Each
has
the
same
basic
components

and
operating
principles
.
The
most
notable
difference
is
that

1996
and
later
cars
use
a
sophisticated
OBD
II-compliant
sys-

tem
.
See
Table
a
.

Table
a
.
Engine
Management
System
Variants

Engine
code/year



1
System

4-cy1inder
M42
(1
.8
I)
1992-1995



Bosch
DME
Ml
.7
M44
(1
.91)
1996-1998



~
Bosch
DME
M5
.2
(OBD
II)

6-cylinder
M50
1992
(2.5
I)



Bosch
DME
M3
.1
1993-1995
(2.5
I)



Bosch
DME
M3
.3.1
(VANOS)
M52
1996-1998
(3281-
2
.8
I)



Siemens
MS
41
.1
(OBD
II)
1998
(3231
-
2
.5
I)



Siemens
MS
41
.1
(OBD
II)
M-Power
S50US
(M3
-
3
.01)
1995



Bosch
DME
M3
.3
.1
S52US
(M3
-
3
.21)
1997-1998



Siemens
MS
41
.1
(0131)
11)

NOTE-

-
Descriptions
and
procedures
in
the
first
partof
this
re-

pairgroup
refer
to
all
the
various
engine
management
systems
.

"
Particulars
of
each
fuel
injection
system
are
treated
in
separate
sections
in
the
second
part
of
this
repair
group
.

GENERAL

Fig
.1
.



OBD
II
diagnostic
connector
locatíon
.

The
fuel
injection
system
is
completely
electronic
in
opera-

tion
.
Air
flow
is
measured
electronically
via
a
mass
air
flow

sensor
and
additional
sensors
supply
information
about
en-

gine
operating
conditions
.
The
ECM
calculates
the
amount
of
fuel
needed
for
the
correct
air-fuel
ratio
and
actuates
the
fuel

injectors
accordingly
.
The
amount
offuel
metered
to
theen-

gine
is
determined
by
how
long
the
injectors
are
open
.

Airintake
.
Air
entering
the
engine
passes
through
a
pleat-

ed
paper
air
filter
in
the
air
cleaner
.
Intake
air
volume
or
mass

is
then
measured
bya
mass
air
flow
(MAF)
sensor
.
In
al¡
ex-

cept
the
vane
type
sensor
(DME
M1
.7),
a
reference
current
is

used
to
heat
a
thin
wireor
film
in
the
sensor
when
the
engine

is
running
.
The
current
used
to
heat
the
wire/film
is
electroni-

cally
converted
into
a
voltage
measurement
corresponding
to

the
mass
of
the
intake
air
.

Table
b
.
Mass
Air
Flow
Sensor
Variants

System



Al
r
flow
sensor
type

Bosch
DME
M1
.7



Vane
(volume
sensor)

Bosch
DME
M3
.1



Hot
wire
(mass
sensor)

Bosch
DME
M3
.3
.1



Hot
film
(mass
sensor)

Bosch
DME
M5
.2



Hot
film
(mass
sensor)

Siemens
MS
41
.1



Hot
film
(mass
sensor)

"
The
16-pin
OBD
11
diagnostic
connector
is
located
on



NOTE-

the
lower
left
dashpanel
.
See
Fig
.
1
.



On
cars
equipped
wíth
tractioncontrol,
an
additional
throttle
valve
is
controlled
by
an
electronic
throttle
actu-
ator
(motor)
.
This
valve
is
used
for
engine
speed
inter
vention
.
Repair
information
forthis
system
is
notcovered
here
due
to
the
special
electrical
testing
equip-
ment
required
to
service
it
.

FUEL
INJECTION



130-
3

Fuel
metering
.
The
ECM
meters
fuel
bychanging
the



The
engine
management
system
compensates
automatical-
opening
time
(pulsewidth)
of
the
fuel
injectors
.
To
ensure
that



ly
for
changes
in
the
engine
due
to
age,
minor
wear
or
small
injector
pulsewídth
is
the
only
factor
that
determines
fuel
me-



problems,
such
as
a
disconnected
vacuum
hose
.
Asa
result,
tering,fuel
pressure
is
maintained
bya
fuel
pressure
regula-



idle
speed
and
mixture
do
not
need
lo
be
adjustedas
partof
tor
.
The
injectors
are
mounted
lo
a
common
fuel
supply
called



routine
maintenance
.
the
fuel
rail
.

The
ECM
monitors
engine
speed
to
determine
the
duration



NOTE-

ofinjector
openings
.
Other
signals
to
the
ECM
help
determine



Poordriveabilitymaybe
encountered
when
the
batteryis

injector
pulse
time
for
different
operating
conditions
.
A
tem-



disconnected
and
reconnected
.
when
the
battery
is
dis-
connected,
the
adaptive
memory
is
lost
The
system
will
perature
sensor
signals
engine
temperature
for
mixture
adap-



readaptafterabout
ten
minutes
of
drfving
.
tion
.
A
throttle
position
sensor
signals
throttle
position
.
The
exhaust
oxygen
sensor(s)
signal
information
about
combus-
tion
efficiency
for
control
of
the
air-fuel
mixture
.
1992
to
1995



DISA
(Dual
Resonance
Intake
System)
engines
are
equipped
with
a
single
sensor
.
1996
and
later
(OBD
II)
engines
are
equipped
with
an
oxygen
sensor
before



TheE36
4-cylinder
engine
is
equipped
with
a
dual
intake
andone
after
each
catalytic
converter
.
Forexample,the
M52



runner
system,
termed
DISA
.
DISA
offers
the
advantages
of
engine
is
equipped
withfour
oxygen
sensors
.



both
short
and
long
intake
pipes
.
Long
intake
runners
are
most
useful
at
low
to
medium
engine
rpm
for
producing
good
Idle
speed
control
.
ldle
speed
is
electronically
controlled



torque
characteristics
.
Short
intake
runners
produce
hígherviathe
idle
speed
control
valve,
which
maintains
idle
speed
by



horsepower
at
hígher
engine
speeds
.
bypassing
varying
amounts
of
air
around
theclosed
throttle
valve
.
Idle
speed
is
not
adjustable
.



NOTE-

Knock
(detonation)
control
.
Knock
sensors
monitor
and



The
term
DISA
comes
from
the
German
words
Differen-

control
ignition
knock
through
the
ECM
.
The
knock
sensors



zierte
Sauganlage,
and
can
roughlybe
translated
as
"dif-
fering
intake
manifold
configuration
."
See
100
Engine-
function
like
microphones
and
are
able
to
convert
mechanical



General
foradditional
information
on
DISA
operation
.
vibration
(knock)
into
electrical
signals
.
The
ECM
is
pro-

grammed
to
react
to
frequencies
that
are
characteristic
of
en-



Manifold
construction
:
The
intake
manifold
is
a
two-piece
gine
knock
and
adapt
the
ignition
timing
point
accordingly
.



metal
construction,
with
a
pair
of
runners
in
thetop
section
See120
Ignition
System
for
further
details
.



and
four
runners
in
the
lower
section
.
A
butterfly
valve
is
in-
stalled
in
the
lower
section,
enabling
the
DISA
solenoid
toiso-

NOTE-



late
one
pair
of
runners
from
the
other
pair
.
See
Fig
.
2
.

The
1992
M50
engine
is
not
equipped
with
knock
sen-



Operation
.
With
the
DISA
butterfly
valve
closed,
the
pipes
sors
.
All
other
engines
are
equipped
with
two
knock



in
thetop
half
of
the
manifold
act
together
with
the
ram
air
sensors
.



pipes
in
the
lower
halfto
producea
single,
long
air
intake
pipe
for
each
cylinder
.
See
Fig
.
3
.
The
column
of
aír
oscíllating
in

Basic
Engine
Settings



this
combined
pipe
significantly
increases
engine
torque
in
the

medium
rpm
range
.

Idle
speed,
idle
mixture
(%CO),
and
ignition
timing
arenot

adjustable
.
The
adaptive
engine
management
system
is
de-

signed
to
automatically
compensate
for
changes
in
engine
op-

eratingconditions,
although
the
adaptive
range
is
limited
.
Once

these
limits
are
exceeded,
driveability
problems
usually
be-

come
noticeable
.

Above
approximately
4,800
rpm,
the
butterfly
valve
between
the
intake
air
pipes
for
the
two
cylinder
groups
is
opened
.
The
shorter
pipes
in
the
lower
manifold
section
now
become
the

main
suppliers
of
ram
air
to
the
cylinders,yielding
greater
pow-

er
at
the
upper
end
of
the
engine
rpm
range
.
See
Fig
.
4
.

Control
components
.
The
DISA
butterfly
valve
is
actuated

NOTE-



electro-pneumatically
via
the
engine
control
module
(ECM)
.

lf
the
system
adaptive
limits
are
exceeded,
the
Check



The
valve
begins
to
open
as
engine
speed
rises
aboye
4,840

Engine
light
will
most
likely
come
on,
indicating
an



rpmand
closes
below
4,760
rpm
.
The
action
of
the
valve
is
de-
emissions-
related
fault
For
Check
Engine
light
diag-



liberately
delayed
to
prevent
it
from
opening
and
closing
repeat-
nostics,
see100
Engine-General
.



edly
within
a
short
time
.

GENERAL

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

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