1998 BMW M3 engine

130-20



FUEL
INJECTION

Fig
.
29
.
Throttleposition
sensor
terminal
identification
on
M50
engine
.

Tableg
.
Throttle
Position
Sensor
Tests

(DME3
.113
.3
.1)

Test
conditions



I
Terminals



I
Testvalue

Harness
connector



13
andground



15
VDC
(approx
.)
disconnected,
igni-



in
harness
tion
on



connector

Harness
connector



1
and3
at
sen-
14
k
ohms
(approx
.)
disconnected,
igni-



sor
terminals
tion
off

Throttle
plate
rotat-



1
and
2
at
sen-



Variable
from
1
-
4ked
from
¡dieto
full



sor
terminals



ohms
(approx
.)
with-
throttle
position



out
interruption



¡die
Speed
Control
Valve
Coil
Resistance
Values

"
M50/S50US
engine

NOTE-



Terminals
1
and
2
..
.
................
20
t
5
ohms

On
cars
with
tractioncontrol,
do
not
confuse
the
throttle



Terminals
2
and
3
...................
20
t5
ohms
position
sensor
on
the
main
throttle
body
with
the
throt-



Terminals
1
and
3
..
.
..
:
............
.40
t
5
ohms
tle
positionswitch
on
the
secondary
throttle
body,
where
applicable
.

¡die
speed
control
valve,
testing

¡die
speed
is
maintained
by
the
ECM
through
the
¡die
speed
control
valve
.
The
¡die
controlfunction
compensates
for
engine
load
and
engine
operating
conditions
.
¡die
speed
is
adaptive
through
the
ECM
and
no
¡die
speed
adjustments
can
be
made
.

NOTE-
Before
testing
the
valve,
confirm
that
the
throttle
position



The
idle
speed
controlvalve
receives
positive
(+)
bat-
sensor
is
working
correctly
.



tery
voltage
from
the
main
relay
.

BOSCH
DME
M3
.
1
AND
M3
.3
.1
COMPONENT
TESTS
AND
REPAIRS

NOTE-

"
The
tests
given
below
are
electrical
checks
only
.
They

do
not
check
the
mechanical
operation
of
the
valve
.
If
the
valve
is
suspected
of
causing
poor
idie,
substitut-
ing
a
known
good
valve
is
the
best
way
to
check
for
a
mechanical
fault
.

1
.
With
engine
running,
check
that
¡die
speed
control

valve
is
buzzing
.

2
.
Turn
on
A/C
or
shift
car
finto
drive
.
¡die
should
remain
steady
orincrease
slightly
.

3
.
If
valve
is
not
buzzing,or
if
¡die
decreases
in
step
2,

stop
engine
and
disconnect
harness
connector
from
valve
.
Check
resistance
of
valve
across
its
terminals
.

See
Fig
.
30
.
Test
values
are
listed
below
.

NOTE
-

If
you
suspect
an
intermittent
fault,
lightly
tapthe
valve
while
testing
resistance
.

11250

Fig
.
30
.
¡die
speed
control
valve
terminal
identification
.

4
.
With
valve
harnessconnector
disconnected,
check
for
battery
voltage
at
red/white
wire
in
connector
with
igni-

tion
tumed
on
.

"
If
there
is
no
voltage,
check
wiring
between
connec-
tor
and
main
relayterminal
87
.
See
Electrical
Wiring
Diagrams
.

5
.
If
voltage
is
presentas
described
above,
check
wiring
between
ECM
and
valve
.
If
no
wiring
faults
are
found,
check
ECM
signal
to
valve
.

NOTE-



NOTE-
"
The
Ole
speed
control
valve
signal
can
be
checked



The
intake
manifold
is
held
in
place
with
7
nuts
from
using
a
duty
cycle
meter
(or
dwellmeter)
.
Connect
the



above
and
2
support
bracket
bolts
from
undemeath
.
On
meter
to
the
valve
following
the
manufacturer's
in-



DME
3
.1
cars,
carefully
disconnect
the
idleair
hose
from
structions
.
Turn
on
the
WC
or
create
a
larga
air
leak



theintake
manifold
when
lifting
the
manifold
off
.
For
more
and
check
that
the
meter
reading
reacts
while
the
idle



information,
sea
113
Cylinder
HeadRemovaland
In-
speed
remainssteady
.



stallation
.

"
There
are
some
additional
inputs
to
the
control
mod-
ule
that
affect
idle
speed
(Le
.
throttle
position,
AIC-on



5
.
Disconnect
al¡
necessary
hoses
andremove
idle
speed
signals,
andAIT
Drive
position)
.
Check
these
signals



control
valve
.
if
idle
problems
persist
.
See
Tabla
i
orTable
j
.

Idle
speed
control
valva,
replacing

The
idle
speed
control
valve
is
mounted
beneath
the
intake
manifold
.
Accessing
the
valva
is
best
accomplishedby
first
re-
moving
the
intake
manifold
.

NOTE-

¡tis
recommended
that
the
intake
manifold
gaskets
be
replaced
whenever
the
intake
manifold
is
removed
.

1
.
Remove
top
enginecovers
from
engine
.
See
Fig
.
31
.

FUEL
INJECTION



130-21

6
.
Installation
is
reverse
of
Removal
.
Use
new
gaskets
when
installing
intake
manifold
.

NOTE-

Poor
driveability
may
be
noticed
afterinstalling
a
re-
placement
idle
speed
control
valve
.
After
about
10
min-
utes
of
driving,
the
system
will
adapt
the
base
setting
of
the
valva
and
the
idle
speed
should
retum
to
normal
.

Tightening
Torque

"
Intakemanifold
to

cylinder
head
(M7)
........
..
.
15±2
Nm
(11
ti
ft-Ib)

BOSCH
DME
M5
.2

COMPONENT
REPLACEMENT

On-Board
Diagnostics
11
(OBD
II)
is
incorporated
into
the

Bosch
DME
M5
.2
engine
management
systems
used
on
the

M44
engine
.
OBD
II
is
capable
of
detecting
a
full
range
of

faults
.
When
faults
are
detected,
a
Diagnostic
Trouble
Code
(DTC)
is
stored
in
the
system
ECM
.
The
Check
Engine
warn-
ing
light
will
also
come
on
if
an
emissions-relatad
fault
is
de-
tected
.

The
most
efficient
way
to
diagnose
the
Bosch
OBD
II
sys-

tem
is
by
using
a
specialized
scan
tool
.
The
OBD
II
system
is

capable
of
storing
hundreds
of
faults,
making
diagnostics
with

a
scan
tool
the
only
viable
method
.
Therefore,
system
diag-
nostics
is
not
covered
here
.

Fi



31
.
Remove
to
en
ine
covers
b



in
out
caPs
and
removin



NOTE-

nuts
(A)
9
.



P



g



y
Pry
g



g



"
The
OBD
11
fault
memory
(including
an
iiluminated
Note

14


L-te
at
cover
edge
(arrows)
.
Check
Engine
light)
can
only
be
reset
using
the
spe-
cial
scan
tool
.
Removing
the
connector
from
the
ECM
2
.
Remove
two
hold
down
nuts
from
fuel
injector
wiring



or
disconnecting
the
battery
will
not
arase
the
fault
duct
.
Pry
back
injector
connector
retainers
and
lift
off



memory
.

wiring
duct
.



"
The
16-pin
OBD
Il
diagnostic
connector
is
located
on
the
lower
left
dash
panel
.
Refer
to
Fig
.
1
.
3
.
Disconnect
intake
air
bootfrom
throttle
housing
.
Where

applicable
disconnect
accelerator
cable
and
cruise



"
BMW
special
scan
tool
ora
`generic"OBD
II
scan
tool

control
cable
from
their
brackets
.



must
be
used
to
access
DTCs
.

4
.
Unbolt
intake
manifold
and
move
it
out
of
way
enough

to
access
idle
speed
control
valva
.

"
Tablak
lists
engine
control
module
(ECM)
pinouts
for
the
DMEM5
.2
system

BOSCH
DME
M5
.
2
COMPONENT
REPLACEMENT

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
.

001ía4
i

Fig
.
34
.
Intake
air
temperature
(IAT)
sensor
in
top
section
of
air
filter
housing
.

¡die
speed
control
valve,
replacing

side
of
the
throttle
body
.
See
Fig
.
35
.

1
.
Disconnect
harness
connector
from
¡die
valve
.

0012725

Fig
.
35
.
M44
engine
:
Throttle
housing
showing
(A)
throttle
position
sensor
(fPS)
and
(B)
¡die
speed
control
valve
.

2
.
Remove
twomountingscrews
holding
sensor
to
throttle

housing
.

The
¡die
speed
valve
on
the
M44
engine
is
located
on
the

FUEL
INJECTION



130-23

2
.
Disconnect
vacuum
hose
and
retaining
screws
.

3
.
Pull
¡die
speed
control
valve
from
its
fittings
.

4
.
Installation
is
reverse
of
rémoval
.
Always
replace
0-

rings
and
seals
.

NOTE

Poor
driveability
may
be
notíced
after
installing
a
re-
placement
¡dio
control
valve
.
After
about10
minutes
of
driving,
the
idie
speed
should
retum
to
normal
.

SIEMENS
MS
41
.1

COMPONENT
REPLACEMENT

On-Board
Diagnostics
II
(OBD
II)
is
incorporated
into
the
Si-

emens
MS
41
.1
engine
management
systems
used
in
the

M52
and
S52US
engine
.
Refer
to
Fig
.
36
.

OBD
11
is
capable
of
detecting
a
fui¡
range
offaults
.
When

faults
are
detected,
a
Diagnostic
Trouble
Code
(DTC)
is

stored
in
the
system
ECM
.
The
Check
Engine
warning
light
will
also
come
on
if
an
emissions-related
fault
is
detected
.
The

most
efficient
way
to
diagnose
the
Siemens
OBD
II
system
is

by
using
a
specialized
scan
tool
.
The
OBD
II
system
is
capa-

ble
of
storing
hundreds
of
faults,
making
diagnostics
with
a
scan
tool
the
only
viable
method
.
Therefore,
system
diagnos-

tics
is
not
covered
here
.

NOTE
-

"
The
OBD
11
fault
memory
(including
an
illuminated

Check
Engine
light)
can
only
be
reset
using
the
spe-
cial
scan
tool
.
Removing
the
connector
from
the
ECM
or
disconnecting
the
battery
will
not
erase
the
fault
memory
.

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

the
lower
left
dash
panel
.
Refer
to
Fig
.
1
.

"
BMW
special
scan
tool
ora
"generic"
OBD
11scan
tool

must
be
used
to
access
DTCs
.
3
.
Installation
is
reverse
of
removal
.
No
adjustment
is
nec
essary
.



"
Table
1
lists
engine
control
module
(ECM)
pinouts
forthe
MS
41
.1
systems
.

SIEMENS
MS
41
.
1
COMPONENT
REPLACEMENT

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

130-26



FUEL
INJECTION

Throttle
position
sensor
(TPS),
replacing

The
throttie
position
sensor
is
located
on
the
side
of
the
throttie
housing
.
See
Fig
.
40
.

Fig
.
40
.
M52
engine
:
Throttle
position
sensor
(arrow)
.

1
.
Unplug
harness
connector
from
sensor
.

NOTE
-

On
cars
with
tractioncontrol,
do
not
confuse
the
throttieposition
sensor
on
the
main
throttie
body
wíth
the
throt-
tie
position
switch
on
the
secondary
throttie
body,
where
applicable
.

3
.
Installation
is
reverse
of
removal
.

¡die
speed
control
valve,
replacing

0012700b

The
¡die
speed
control
valve
is
mounted
on
the
underside
of
the
intake
manifoldadjacent
to
the
dipstick
tube
bracket
.
Ac-
cessing
the
valve
is
best
accomplished
by
first
removing
the
throttie
housing
.

1
.
Disconnect
intake
air
bootfrom
throttie
housing
.
Unbolt
throttie
body
and
¡ay
aside
.
(Do
not
disconnect
throttie
cable
or
electrical
harness
connectors
to
throttie
body
.)

2
.
Unbolt
dipstick
tube
bracket
from
intakemanifold
.

3
.
Workíng
under
intake
manifold,
disconnect
electrical
harness
connector
from
¡die
speed
control
valve
.

4
.
Remove
two
bolts
retaining
¡die
speed
control
valve
to
underside
of
intake
manifold
.
Remove
valve
from
intake
manifold
.
Remove
hose
clamp
and
disconnect
hose
.

ECM
PIN
ASSIGNMENTS

mately
one
minute
.

Vacuum
seal

Mounting
bracket

Electrical
connector

0013185

Fig
.
41
.
M52
engine
:
¡die
speed
control
valve
(located
under
intake
manifold)
.

5
.
Installation
ís
reverse
of
removal
.
Use
new
gaskets
when
installing
.

NOTE
-

Poor
driveabilíty
may
be
noticed
atter
installing
a
re-
placement
idle
speed
control
valve
.
After
about
10
min-utes
of
dríving
the
idle
speed
should
return
to
normal
.

ECM
PIN
ASSIGNMENTS

2
.
Remove
twomountingscrews
holding
sensor
to
throttie
housing
.



Engine
control
module
(ECM),
accessing

1
.
Disconnect
negative
(-)
battery
cable
.
Wait
approxi-

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
vüi
.

2
.
Remove
engine
control
module
(ECM)
compartment
cover
from
right
side
of
engine
compartment
rear
bulk-
head
.
Cover
is
retained
withfour
captíve
screws
.
See
Fig
.
42
.

3
.
Disconnect
control
module
harness
connector
by
re-
leasing
fastener
and
pivoting
connectorup
and
off
ECM
.

4
.
Remove
ECM
from
retaining
brackets
and
pull
ECM
from
its
holder
.

5
.
Installation
is
reverse
of
removal
.

0013ZIM
Fig
.
42
.
Engine
control
module
(ECM)
located
in
compartment
in
right-rearof
engine
compartment
(arrow)
.

NOTE-

Replacement
ECMs
must
be
coded
with
application
in-
formation
(Le
.
engine
code,
transmission
type,
etc
.)
pri-
or
to
installation
.
Consult
an
authorized
BMW
dealer
before
replacing
the
ECM
.

ECM
pin
assignments
are
given
in
Tables
h
through
Table
I.
This
information
can
be
helpful
when
diagnosing
faultsto
or
from
the
ECM
.
If
al¡
inputs
and
wiring
are
OK
butoperational
problems
still
exist,
the
ECM
itself
may
be
faulty
.

Fig
.
43
.
ECM
pin
numbers
as
seen
from
back
of
ECM
connector
.

FUEL
INJECTION



130-
2
7

Generally,
absence
of
voltage
or
continuity
means
there
is
a
wiring
or
connector
problem
.
Test
results
with
incorrect
values
do
notnecessarily
mean
that
a
component
is
faulty
:
Check
for
loose,
broken
or
corroded
connections
and
wiring
before
re-
placing
components
.
If
the
results
are
still
incorrect,
test
the
component
itself
.
For
engine
management
system
electrical
schematics,
see
Electrical
Wiring
Diagrams
.

CAUTION-

Always
waitat
least
40
seconds
after
tuniing
off
the
ignition
before
removing
the
connector
from
the
engine
control
module
(ECM)
.
If
the
connec-
tor
is
removed
before
this
time,
residual
power
in
the
system
relay
may
damage
the
ECM
.

"
Always
connector
disconnect
the
control
module
connector
and
meter
probes
with
the
ignitionoff
.

When
making
checks
at
the
ECM
itself,
a
breakout
box
should
be
used
to
allow
tests
to
be
made
with
the
connector
attached
to
the
ECM
.
This
also
prevents
damage
tothe
small
termínals
in
the
connector
.
As
an
alternative,
theharness
con-
nector
housing
can
be
separated
so
that
electrical
checks
can
be
made
from
the
back
of
the
connector
.
ECM
pin
numbering
is
shown
in
Fig
.
43
.

NOTE
-

On
cars
with
tractioncontrol,
do
not
confuse
the
throttle
position
sensor
on
the
main
throttle
body
with
the
throt-
tle
position
switch
on
the
secondary
throttle
body
.

27
Lb
2L4
LJ
22
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1
>I-
0013211

ECM
PIN
ASSIGNMENTS