torque BMW M3 1998 E36 Repair Manual

121-
6



BATTERY
STARTER,
ALTERNATOR

Alternator,
removing
and
installing

(6-cylinder
engine)

A
replacement
alternator
should
have
the
same
rating
as

the
original
.
Alternator
manufacturer
and
ampere
rating
are

normally
marked
on
the
alternator
housing
.

1
.
Disconnect
negative
(-)
battery
cable
.

CAUTION-

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

2
.
Remove
alternator
cooling
duct
and
air
filter
housing

assembly
from
car
.
Disconnect
wiring
from
rear
of
alter-

nator
.

3
.
Remove
radiator
cooling
fan
and
fan
shroud
.
See
170

Radiator
and
Cooling
System
.

4
.
Remove
alternator
drive
belt
from
alternator
pulley
.
On

engines
with
hydraulic
belt
tensioner,
remove
tensioner

idler
pulley
(upper
roller)
from
alternator
bracket
.
See

Fig
.
5
.

ALTERNATOR
SERVICE

Fig
.
5
.



Pry
off
cover
from
tensioner
and
then
lever
tensioner
clock-
wise
to
release
belt
tension
.
Remove
upper
roller
(A)
once
belt
ís
removed
.

NOTE-

If
reusing
drive
belt,
mark
direction
of
rotation
on
belt

before
removing
.

5
.
Remove
upper
and
lower
mounting
bolts
and
lift
out
al-

ternator
.

6
.
Installation
is
reverse
of
removal
.
Note
locating
notches
on
tensioner
idler
pulley
(upper
roller)
alternator
brack-

et
when
installing
pulley
.

Tightening
Torques

"
D+
wire
to
alternator
(M6
nut)
.......
7
Nm
(53
in-lb)

"
B+
wireto
alternator
(M8
nut)
.......
13
Nm
(10
ft-Ib)

"
Pulley
to
alternator
(M16
nut)
.......
60
Nm
(44
ft-Ib)

Voltage
regulator,
removing
and
installing

1
.
Disconnect
negative
(-)
cable
from
battery
.

NOTE-



2
.
Remove
alternator
as
described
earlier
.

The
radiator
cooling
fan
nut
(32
mm
wrench)has
left-
hand
threads
.



3
.
Remove
cooling
duct
from
rear
of
alternator
.
See
Fig
.
6
.

Alternator

.
.g-



p~
J

-..
.

Fig
.
6
.



Alternator
assemblyand
related
parts
.

Cooling
duct

0012524

4
.
Remove
voltage
regulator
mounting
screws
and
re-

move
regulator
from
alternator
.

5
.
Installation
is
reverse
of
removal
.
Clean
brush
contact

surfaces
in
alternator
and
check
brush
length
asde-

scribed
later
.

121-
8



BATTERY,
STARTER,
ALTERNATOR

1f
the
solenoid
audibly
cliicks
but
the
motor
does
not
turn,



Starter,
removing
and
installing
switch
on
the
lights
andtum
the
key
to
the
start
position
.
lf
the



(6-cylinder
engine
with
lights
go
out
while
attempting
to
start,
the
battery
cable
may
be



manual
transmission)
loose
or
the
starter
may
have
a
short
circuit
.
If
the
lights
stay

on,the
solenoid
is
most
likely
atfault
.
The
starter
on
a
6-cylinder
car
with
manual
transmission
is

Starter,
removing
and
installing

(4-cylinder
engine)



1
.
Disconnect
negative
(-)
battery
cable
.

1
.
Disconnect
negative
(-)
cable
from
battery
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery

disconnection
cautions
given
at
the
front
of
this

manual
on
page
viii
.

2
.
Remove
guide
tube
for
oil
dipstick
.

3
.
Raise
vehicle
.

WARNING
-

Make
sure
the
car
ís
stable
and
wefl
supported
at
all
times
.
Use
a
professional
automotive
lift
or
jack
stands
designed
forthe
purpose
.
A
floor
jack
is
not
adequate
support
.

4
.
Disconnect
wiring
from
starter
.

5
.
Remove
top
and
bottom
starter
bolts
.
Bottom
bolt
must

be
removed
from
below
car
.
Remove
starter
support

bracket,
if
applicable
.

removed
from
below
.

2
.
Raise
vehicle
.

3
.
Remove
reinforcing
cross
bracefromunder
transmís-

sion,
if
applicable
.

4
.
Remove
cover
from
fuel
filter
and
fuel
lines
on
left
side

underneath
car,
if
applicable
.
Detach
fuel
lines
and
har-

ness
connectors
from
retainingbrackets,
as
necessary

5
.
Disconnect
wiring
from
starter
.

6
.
Loosen
andremove
bolts
and
nuts
fastening
starter
to

transmission
bell
housing
and/or
engine
block
.
Remove

starter
supportbracket
.

7
.
Remove
starter
from
below
.

8
.
Check
starter
pinion
gear
and
flywheel
teeth
for
dam-

age
.

9
.
Installation
is
reverse
of
removal
.

6
.
Pull
starter
downward
and
turn
until
solenoid
is
at
top,



Tightening
Torques

then
remove
from
car
.



"
Re¡
nforcing
cross
brace

to
chassis
(M10)
..
...............
42
Nm
(31
ft-Ib)

7
.
>Check
starter
pinion
gear
and
flywheel
teeth
for
dam-



"
Starter
to
engine
block
(M10
bolt)
...
50
Nm
(37
ft-Ib)

age
.



"
Support
bracket
to
starter
(M5
nut)
...
5
Nm
(44
in-lb)

"
Support
bracket

8
.
Installation
is
reverse
of
removal
.



to
engine
block
(M10
bolt)
.........
47
Nm
(35
ft-Ib)

"
Wire
to
terminal
50
(M6
nut)
.........
6
Nm
(53
ín-Ib)

"
Wire
to
terminal
30
(M8
nut)
.........
12
Nm
(9
ft-lb)

Tightening
Torques

"
Starter
to
engine
block
(M10
bolt)
...
50
Nm
(37
ft-lb)

Wire
to
terminal
50
(M6
nut)
........
6
Nm
(53
in-lb)

"
Wire
toterminal
30
(M8
nut)
...
,
..:.
12
Nm
(9
ft-Ib)

STARTER
SERVICE

121-1
O



BATTERY,
STARTER,
ALTERNATOR

9
.
Remove
starter
from
above
.

10
.
Check
starter
pinion
gear
and
flywheel
teeth
for
dam-
age
.

11
.
Installation
is
reverse
of
removal
.

Tightening
Torques

"
tntakemanifold
to
cylinder
head

M7
nut
...
.
................
...
.
15
Nm
(11
ft-Ib)

M8
nut/bolt
.............
.
.
..
...
22
Nm
(16
ft-Ib)

"
Starter
to
engine
block
(M10
bolt)
...
50
Nm
(37
ft-Ib)

"
Support
bracket
to
starter
(M5
nut)
...
5
Nm
(44
in-lb)

"
Support
bracket

to
engine
block
(M10
bolt)
.
.
..
..
...
47
Nm
(35
ft-Ib)

"
Wire
toterminal
50
(M6
nut)
.
..
.....
6
Nm
(53
in-lb)

"
Wire
toterminal
30
(M8
nut)
...
.....
12
Nm
(9
ft-Ib)

Solenoid
switch,
removing
and
installing

1
.
Remove
starter
as
described
above
.
Tightening
Torque

2
.
Remove
cover
from
solenoid
switch
.



"
Field
winding
strap
to
starter
(M8)
...
.
12
Nm
(9
ft-Ib)

3
.
Disconnect
fieid
winding
strap
between
starter
motor

and
solenoid
switch
.

NOTE-

The
condition
of
the
field
winding
strap
is
critical
.
If
it
is
damaged,
bumed
or
partially
melted
through,
a
new
or

rebuilt
starter
motor
is
needed
.

4
.
Remove
solenoidswitch
mounting
screws,
and
sepa-

,
rate
solenoid
from
starter
.
See
Fig
.
12
.

CAUTION-

When
installing
fieid
winding
strap
to
starter,
posi-

tion
it
so
that
it
does
not
contact
the
starter
body
.

STARTER
SERVICE

131~184

Fig
.
12
.
Starter
solenoid
mounting
screws
(arrows)
are
tight
.
Use
en
impact
screwdriver
to
loosen
the
screws
.

5
.
Installation
is
reverse
of
removal
.
Lubricate
solenoid
pistos
with
light
grease
.

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

130-
4



FUEL
INJECTION

Main
Relay

Fig
.
2
.



DISA
system
components
.
DISA
is
controlled
via
theengine
control
module
(ECM)
.

Fig
.
3
.



DISA
manifold
runners
with
butterfly
valve
closed
for
lowrpm-
high
torque
operation
.

yje
q

GENERAL

high
power
operation
.

0012734

Fig
.
4
.



DISA
manifold
runners
with
butterfly
valve
open
for
high
rpm-

On-Board
Diagnostics
(OBD)

and
Fault
Diagnosis

Poor
driveability
may
have
a
variety
of
causes
.
The
fault

may
He
withthe
ignition
system,
the
fuel
system,
parts
ofthe

emission
control
system,
ora
combination
of
thethree
.
Be-

cause
of
these
interrelated
functions
and
their
effects
on
each
other,
it
is
often
difficult
to
know
where
to
begin
looking
for

problems
.

For
this
reason,
effective
troubleshooting
should
always
be-

gin
with
an
interrogation
of
the
On-Board
Diagnostic
(01313)

system
.

The
OBD
system
detects
certain
emissions-related
engine

management
malfunctions
.
When
faults
are
detected,the

OBD
system
storesa
Diagnostic
Trouble
Code
(DTC)
in
the

system
ECM
.
In
addition,
the
Check
Engine
warning
light
will

come
on
if
an
emissions-related
fault
is
detected
.

Two
generations
of
OBD
are
used
on
thecars
covered
by
this
manual
.
See
100
Engine-General
for
OBD
I
information

and
fault
codes
.

On-Board
Diagnostics

"
1992-1995models
....
.
...
...
.
...
......
OBD
I

"
1996-1998models
....
.
..
.
.
.
..
...
......
OBD
II

Oxygen
Sensor
FUEL
DELIVERY
TESTS
FUEL
INJECTION



130-
9

"
Voltage
at
¡dle
..
.
..
..
....
0
.2
to
0
.8
VDC,
fluctuating



Checking
fuel
delivery
is
afundamental
part
of
trouble-
shooting
and
diagnosing
the
engine
management
system
.
Fuel
pressure
directly
influences
fuel
delivery
.
An
accurate

NOTE-



fuel
pressure
gauge
will
be
needed
to
make
the
tests
.

To
check
sensorresponse
to
lean
and
rich
mixtures,
createenairleak,
orpull
vacuumhoseofffue¡
pressure



There
are
three
significant
fuel
delivery
values
to
be
mea-

regulator
to
increase
fuel
pressure
.



sured
:

3
.
Separate
sensorharness
connector
from
sensor
.
Check

for
battery
voltage
between
terminals
3
and
4
(green

wire
and
brown
wire)
in
main
wiring
harness
side
of
con-

nector
with
engine
running
.
If
voltage
is
not
present,

check
oxygen
sensor
heater
relay
.
See610
Electrical

Component
Locations
.

4
.
Check
heater
element
resistance
between
terminals
3
and
4
in
sensor
side
of
connector
.
If
element
is
electri-

cally
open
(no
continuity),
replace
sensor
.

NOTE-

The
oxygen
sensor
heater
relay
is
mounted
in
the
main
power
distributfon
box
in
the
left
rear
of
the
engine
com-
partment
.
Refer
to
Fig
.
6
.
The
heater
relay
is
energized
wíth
positive
(+)
battery
voltage
from
the
main
relayanda
switched
ground
from
the
ECM
.
See
Electrical
Wir-
ing
Diagrams
.

"
Oxygen
sensor
to
exhaust
pipe
...
..
55
Nm
(41
ft-Ib)

"
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,
suchasclogged
fuel
filter
.

"
Residual
pressure-the
pressure
maintained
in
the
closed
system
after
the
engine
and
fuel
pump
are
shut

off
.

Procedures
for
measuring
the
first
two
quantities
arede-
scribed
in
160
Fuel
Tank
and
Fuel
Pump
.
Residual
fuel
pres-
sure
is
checked
using
the
procedure
detailed
later
in
this

group
.

Operating
fuel
pump
fortests

To
operate
the
fuel
pump
for
testing
purposes
without
hav-

íng
to
runthe
engine,
the
fuel
pump
relay
can
be
bypassed
to

power
the
pump
directly
.
Fuel
pump
relay
location
is
shown
in

Fig
.
6
.

5
.
¡f
oxygen
sensor
doesn't
produce
a
fluctuating
voltage



To
runthe
fuel
pump,
remove
the
fuel
pump
relay
and
con-
and
preheater
circuit
is
OK,
replace
sensor
.



nect
the
socket
for
relayterminal
30
to
the
socket
for
relay
ter-

mina¡
87
with
a
fused
jumper
wire
.
After
completing
the
tests,

NOTE-



remove
the
jumper
wire
.

If
not
already
applied,
coat
the
oxygen
sensor
threads
with
an
anti-seize
compound
before
installation
.
Do
not



CAUTION-
getthe
compound
on
the
sensor
tip
.
"
Relay
locations
may
vary
.
Use
care
when
identi-
fying
relays
and
making
electrical
checks
at
the
fuselrelay
panel
.
See
610
Electrical
Compo

Tightening
Torque



nent
Locations
for
additional
relay
information
.

"
The
fuel
pump
relay
has
a
1
.5
mm2
red
wire
at
ter-
minal
30
in
the
relay
socket
.
Terminal
87
has
a
1
.5
mm
2
greenlviolet
wire
.
See
Electrical
Wiring
Di-
agrams
for
additional
wiring
information
.

NOTE-

Thejumper
wire
should
be
1.5
mm2
(14
ga
.)
and
in-
clude
an
in-line
tuse
holder
with
a15
amp
tuse
.
To
avoid
fuselrelay
panel
damage
from
repeated
connect-
ing
and
disconnecting,
also
include
a
toggle
switch
.
A
heavy-duty
jumper,
BMW
tool
no
.
61
3
050,
is
also
available
from
an
authorized
BMW
dealer
.

FUEL
DELIVERYTESTS

6
.
Remove
fuel
rail
mounting
bolts
.
See
Fig
.
17
.

0012504

Fig
.
17
.
Location
of
fuel
rail
mounting
bolts
(A)
and
fuel
inlet
and
return
lines
(B)
on
M44
engine
.
Upper
manifold
has
been
removed
.

7
.
Pull
upon
fuel
rail
and
remove
injector
rail
with
injec-tors
.
Remove
individualinjectors
by
removing
injector

retaining
clip
and
pullinginjector
from
rail
.
See
Fig
.
18
.

Fig
.
18
.
Pry
retaining
clip
from
injector
(1),
then
pull
injector
from
rail
(2)
.

8
.
Installation
is
reverse
of
removal
.

Tightening
Torque

"
Fuel
rail
to
cylinder
head
..
.
..
..
...
10
Nm
(89
in-lb)

FUEL
INJECTION



130-
1
3

Fuel
Pressure
Regulator

The
fuel
pressure
regulator
location
on
E36
models
is

mounted
in
one
of
two
locations
:

Fuel
Pressure
Regulator
Location

"
4-cylinder
engines

1992-
January
1997
............
...
..
on
fuel
rail

January
1997-
on
...............
..
...
under
car

"
6-cylinderengines

1992-1995
.
.
...
...
.
...........
...
..
on
fuel
rail

1996-on
..
.
..
................
...
...
undercar

Fuel
pressure
regulator,
replacing

(fuel
rail
mount)

WARNING
-

Fuel
will
be
discharged
.
Do
not
disconnect
any
wires
that
could
cause
electrícal
sparks
.
Do
not
smoke
or
work
near
heaters
or
other
fire
hazards
.
Keepan
approved
fire
extinguisher
handy
.

9
.
On
6-cylinder
engines,
remove
top
engine
covers
.
Re-
move
fuel
rail
mounting
bolts
and
lift
up
fuel
rail
.

1
.
Disconnect
vacuum
hose
from
fuel
pressure
regulator
.

See
Fig
.
19
.

"
Fit
new
O-rings
when
installing
injectors
.
For
ease
of

installation,
lightly
lubricate
O-rings
with
SAE
90
or



0012732

equivalent
lubricant
.



Fig
.
19
.
Fuel
pressure
regulator
(arrow)
on
M42
engine
.
Vacuum
hose

"
Check
that
injector
electrical
connections
are
correctly



shown
at
A
.

fitted
and
that
injectors
are
fully
seated
prior
to
install-

ing
fuel
rail
mounting
bolts
.



2
.
Remove
bolt
from
regulator
clamp
.
Remove
clamp
.
Note

"
Replace
wire
ties
.



installed
direction
of
regulator
to
fuel
rail
.

3
.
Wrap
a
shop
rag
around
regulator,
then
remove
regula-

tor
from
fuel
rail
by
pulling
straight
out
.

FUELDELIVERYTESTS

u0
I
.[
Ia

Fig
.
21
.
Air
flow
sensor
harness
connector
terminal
identification
.

4
.
Replacing
air
flow
sensor
:

"
Remove
large
band
clamp
attaching
air
boot
to
sensor
.

"
Remove
airfiltertop
cover,
then
remove
airflow
sensor

mounting
nuts
inside
cover
.

"
Reconnect
air
boot
and
harness
connector
.

Engine
coolant
temperature
(ECT)
sensor,

testing
and
replacing

The
engine
coolant
temperature
(ECT)
sensor
sends
con-

tinuous
engine
coolant
temperature
information
to
the
ECM
.

As
temperature
increases,
sensor
resistance
decreases
.

"
With
harness
connector
disconnected,
check
resis-

tance
across
sensor
terminals
.

"
Compare
tests
results
to
values
in
Table
d
.

FUEL
INJECTION



130-
1
5

0011984

Fig
.
22
.
M42
engine
coolant
temperature
(ECG
sensor
(arrow)
.

Table
d
.
Engine
Coolant
Temperature
Sensoror

Intake
Air
TemperatureSensor
Test
Values

(DME
1
.7)

Test
temperatures



Resistance
(k
ohms)
',

14±2°F(-10t1°C)



7-11
.6

68±2°F
(20
t
1
°C)



2
.1
-2
.9

176
±
2°F
(80
t
V
C)



0
.27-0
.40

The
ECT
sensor
is
located
under
number
one
intake
run-



'

ner
.
See
Fig
.
22
.
NOTE-

1
.
Check
ECM
referente
voltage
to
sensor
:



The
test
values
listed
represent
only
three
test
points
from
a
continuous
resistance
NTC
sensor
.
Check
the
"
Disconnect
harness
connectorfrom
ECT
sensor
.



full
linear
response
to
increasing
temperature
as
the
"
Turn
ignition
key
on
.



engine
warms
up
.
"
Check
for
5
volts
between
supply
voltage
(brown/red)

wire
of
harness
connector
and
ground
.



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

"
Turn
ignition
key
off
.



replaced
.
If
no
faults
are
found,
reconnect
electrical
"
If
voltage
is
not
present
or
incorrect,
check
wring
from



harness
.

ECM
and
check
ECT
sensor
reference
voltage
output

at
ECM
.
See
Table
h
.
NOTE-

2
.
Check
ECT
sensor
resistance
:



Use
a
new
copper
sealing
washer
when
installing
sen-
sor
.
Reptace
any
lost
coolant
.

WARNING
-

Do
not
replace
the
ECT
sensor
unlessthe
engine
is

cold
.
Hot
coolant
can
scald
.

Tightening
Torque

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

BOSCH
DME
M1
.7
COMPONENT
TESTS
AND
REPAIRS

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

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