wiring harness BMW M3 1995 E36 Owner's Manual

BOSCH
DME
MM
AND
M33
.1

COMPONENT
TESTS
AND
REPAIRS

Consult
Table
a
for
engine
application
information
for
the

Bosch
DME
3
.1
and
3
.3.1
systems
.

The
DME
3
.1
and
DME
3
.3
.1
systems
are
similar
in
opera-

tion,
with
knock
control
and
VANOS
operation
being
the
key

differences
.
DME
3
.1
engines
arenot
equipped
with
VANOS

or
knock
detectors,
while
the
DM
E3
.3
.1
system
is
.

CA
UTION-

Use
onty
a
digital
multimeter
when
testing
wiring
.
Use
of
an
analog
VOM
may
damage
the
engine
control
module
.

Fig
.
25
.
Mass
air
flow
sensor
.
Hot
wire
sensor
usedon
carswith
DME
Electrical
tests
of
the
main
and
fuel
pump
relays
and
the



3
.1
(1992
6-cylinder
models)
.

DME
engine
control
module
(ECM)
are
covered
earlier
in
this

section
.
Fuel
pump
tests
are
covered
in
160
Fuel
Tank
and



CAUTION-
Fuel
Pump
.
Use
only
a
digital
multimeter
when
checking
the
mass
air
flow
sensor
.
An
analog
meter
can
dam-
Mass
Air
Flow
Sensor



age
theair
flow
sensor
.

There
are
two
types
of
mass
air
flow
sensors
used
onthe



1
.
Disconnect
air
flow
sensor
from
air
cleaner
only
.
Leave

cars
covered
by
this
section
.
Testing
procedures
vary
de-



it
connected
to
duct
leading
to
intake
manifold
and

pending
on
type
installed
.
The
airflow
sensor
is
not
adjustable



leave
wiring
harness
connected
.

and
must
only
be
tested
with
a
digital
multimeter
.

Mass
Air
FlowSensor
Variants

"
1992
M50
engine

DME
M3
.1
.
.
.
.
...
..
mass
air
flow
sensor-hot
wire

"
1993-1995
M50
and
S50US

DMEM33
.1)
.
...
...
.
mass
air
flow
sensor-hot
film

Mass
air
flow
sensor
(hot
wire),

testing
and
replacing

When
the
engine
is
running,
a
current
is
used
to
heat
a
thin

wire
in
the
center
of
the
sensor
.
See
Fig
.
25
.
The
current
in
the

wire
is
regulated
to
maintain
a
temperature
of
100°C
more

than
the
air
passing
over
it
.
The
current
used
to
heat
the
wire

is
electronically
conneced
into
a
voltage
measurement
corre-

sponding
to
the
mass
of
intake
a¡
r
.

To
keep
the
wire
clean,
it
is
heated
to
a
temperature
of
about

1,000°C
(1,830°F)
for
one
second
.
This
"burn-off"
cycle
takes

place
automatically,
four
seconds
after
the
engine
is
tumed
off
.

lf
thehot
wire
breaks
or
if
there
is
no
output
from
the
air
flow

sensor,
the
ECM
automatically
switches
to
a
"limp-home"

mode
and
tucos
on
the
Check
Engine
light
.
The
engine
can

usually
be
started
and
driven
.
The
air
flow
sensor
has
no
inter-

nal
moving
parts
and
cannot
be
serviced
.

FUEL
INJECTION



130-
1
7

2
.
Start
engine
and
run
it
to
normal
operating
temperature
.

3
.
Rev
engine
toat
least
2,500
rpm,then
shut
it
off
.
Look

through
meter
at
hot
wire
.
After
approximately
four
sec-

onds
wire
should
glow
brightly
for
about
one
second
.

NOTE
-

If
the
wire
glowsas
specified,
then
the
airflow
meter
and
ECM
are
probably
operating
correctly
.
lf
the
wire
does
not
glow,
continue
testing
.

4
.
lf
the
wire
does
not
glow,
remove
air
flow
sensor
and

look
through
it
to
see
if
wire
is
broken
.
lf
wire
is
broken,

meter
will
have
to
be
replaced
.

5
.
Reinstall
air
flow
sensor
and
harness
connector
.
Peel

back
rubber
bootfrom
harness
connector
.
Working

from
rear
of
connector,
connect
digital
voltmeter
across

terminals
1
and
4
.
See
Fig
.
26
.

6
.
Start
and
rev
engine
toat
least
2,500
rpm,thenshut
it

off
.
After
about
4
seconds,
voltage
should
riseto
about

4
volts
for
about
one
second
.
lf
voltage
is
present,
but

wire
does
not
glow,
air
flow
sensor
is
faulty
and
should

be
replaced
.

7
.
lf
voltage
is
not
present
in
step
6,
turn
ignition
key
on

and
check
for
voltage
and
ground
at
sensor
.
There

should
beground
at
pin
4
.
There
should
be
positive
(+)

battery
voltage
at
pin
2
.

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

130-18



FUEL
INJECTION
The
engine
coolant
temperature
(ECT)
sensor
sends
con-

tinuous
engine
coolant
temperature
information
to
the
ECM
.
Fig
.
26
.
Mass
air
flow
sensor
terminalidentifcation
on
carswith
DME



As
temperature
increases
sensor
resistance
decreases
.
M3
.1
fuel
injection
.

Mass
air
flow
sensor
(hot
film),

testing
and
replacing

MOTE-

A
burn-off
cycle
is
not
used
on
hot
film
sensors
.

8
.
With
ignition
off,
disconnect
harness
connector
from
air



ECT
Sensor
Location
flow
sensor
.
Using
a
digital
multimeter,
check
resis-



"
M50/S50US
engine
............
left
side
of
cylinder
tance
at
terminals
listed
.



head
under
intake
manifold

Air
Flow
Sensor
Test
Values
(DMEM3
.1)

"
Terminals
5
and
6
.
.
.
.........
..
.
..
....
3-4
ohms

If
any
faults
are
found,
check
wiring
lo
and
from
the
ECM
.
Make
ECM
pinout
test
as
listed
in
See
Table
i
.
Main
power
to
air
flow
sensor
comes
from
DME
main
relay
.

On
cars
with
DME
M3
.3
.1
a
hot
film
mass
air
flow
sensor
is
used
.
When
the
engine
is
running,
a
current
is
used
lo
heat
a
thinfilm
in
the
center
of
the
sensor
.
This
current
is
electroni-
cally
converted
into
a
voltage
measurement
corresponding
to
the
mass
of
intake
air
.

If
thehot
film
breaks
or
if
there
is
no
output
from
the
air
flow
sensor,
the
ECM
automatically
switches
to
a
"limp-home"
mode
and
tucos
on
the
Check
Engine
light
.
The
engine
can
usually
be
started
and
driven
.
The
air
flow
sensor
has
no
inter-
nal
moving
parts
and
cannot
be
senricedor
adjusted
.

CA
UTION-

Use
only
a
digital
multimeter
when
checking
the
mass
air
flow
sensor
.
An
analogmetercan
dam-
age
the
air
flow
sensor
.

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

1
.
Disconnect
harnessconnector
from
air
flow
sensor
.

2
.
Turn
ignition
on
and
check
for
voltage
and
ground
at

connector
.
There
should
beground
at
pin
1
.
There

should
be
positive
(+)
battery
voltage
at
pin
3
.
If
any
faults
are
found,
check
wiring
to
and
from
ECM
.
Make
ECM
pinout
test
.
See
Table
j
.

NOTE-

Positive
(+)
battery
voltage
to
air
flow
sensor
comes
from
DME
main
relay
when
the
ignition
is
switch
on
orengine
running
.

Engine
coolant
temperature
(ECT)
sensor,

testing
and
replacing

0012704
Fig
.
27
.
Engine
coolant
temperature
(ECT)
sensor
(A)
is
located
be-
neath
top
engine
cover
(B)
and
crankcase
vent
hose
(C)
.
M52
engine
shown
.
M50
is
similar
.

1
.
Check
ECM
reference
voltage
to
sensor
:
"
Disconnect
harnessconnector
from
ECT
sensor
.
"
Turn
ignition
keyon
.
"
Check
for
5
volts
between
supply
voltage
wire
(brown/red)
wire
of
harness
connector
and
ground
.
"
Turn
ignition
key
off
.
"
If
voltage
is'
not
present
or
incorrect,
check
wiring
from
ECM
and
check
referencevoltage
output
at
ECM
(pin
78)
.
See
Table
i
(DM
E
3
.1)
or
Table
j
(DME
3
.3
.1)

2
.
Check
ECT
sensor
resistance
:

"
With
harnessconnector
disconnected,
check
resis-
tance
acrosssensor
terminals
.
"
Compare
tests
results
to
values
in
Table
f
.

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

130-20



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
.

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

Fig
.
9
.



Fuel
pump
relay
terminal
identification
.

Fuel
Pump
Electrical
Tests

Troubleshooting
of
any
fuel
pump
fault
should
begin
with

checking
the
fuel
pump
fuse
and
the
fuel
pump
relay
.
The
DME
main
relay
should
also
be
checked
.

NOTE-

Special
tools
are
requíred
for
some
of
the
tests
de-
scribed
here
.

Fuel
pump
electrical
circuit,
testing

The
fuel
pump
electrical
circuit
diagram
is
shown
in
Fig
.
10
.

3
.
If
fuel
pump
does
not
run,
disconnect
black
harness

connector
from
tank
sender
unit
.
With
jumper
wire
con-

nectedas
described
in
step
2
above,
check
for
positive

(+)
batteryvoltage
at
harness
connector
terminals
.
See
Fig
.
11
.

FUEL
TANK
AND
FUEL
PUMP



160-
7

From
Main
Relay
(+15
power
with
key
in
run



From
B+juretion
point
orstartposition)
(batteryvoRageatalltirnes)

'
.5
RD/Nrr



1
.5
RD

1
.5
GNNI

From
Engine



2
.5
GNNI
Control
Module



15
2
.5
GNNI

Ground
(below
center
console)

Fig
.
10
.
Fuel
pump
electrical
circuit
.

30

-~
Relay
Fuel
Pump

8~T

I



1

s
ám
61
Front
Power
I



a
1
Distribution
Box
I_
16

WIRING
COLOR
CODE

BK
-
BLACK
BR
-
BROWN
Fuel
Pump



RD



-



RED
(in-tank)
M
YL
YELLOWGN
-
GREENBU
-
BLUE
1
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK

0011946

4
.
If
voltage
and
groundare
present,
fuel
pump
is
proba-
bly
faulty
.
If
there
is
no
voltage,
check
wiring
From
fuel
pump
Reay
and
make
sure
Reay
is
functioning
correctly
.

CAUTION-

Fuseandrelaylocationsmayvary
.
Usecara
when



Fuel
pump
power
consumption,
testing

troubleshooting
the
electrical
system
at
the
fuselrelay
panel
.
To
resolve
problems
in
identify-



NOTE-
ing
a
relay,
see
en
authorízed
BMW
dealer
.



"
To
achieveaccurate
testresults,
fhe
battery
voltage
at
the
connector
should
be
approximately
13
volts
.
1.
Remove
rearseat
cushion,
pull
right
side
insulation
mat



Charge
the
battery
asnecessary
.

back
to
expose
fuel
tank
accesscover
.
Remove
cover



.
q
higher
than
normal
power
consumption
usually
fin-
to
expose
wiring
connections
.



dicates
a
worn
fuel
pump,
which
may
cause
intermit-
tentfuel
starvation
due
lo
pump
overheating
and
2
.
Remove
fuel
pump
relay
and
opérate
fuel
pump
as
de-



seizure
.
The
only
remedy
is
pump
replacement
.
Be
scribed
under
Operating
fuel
pump
for
tests
earlier
.



sure
to
check
that
thereturn
fine
and
the
pump
pickup
Pump
should
run
.
Disconnect
jumper
wire
when
fin-



are
not
obstructed
before
replacing
the
pump
.

ished
.
1
.
Remove
rear
seat
cushion,
pull
right
side
insulation
mal
back
to
expose
fuel
tank
accesscover
.
Remove
cover
to
expose
wiring
connections
.

2
.
Disconnect
(black)
harness
connector
from
fuel
pump
.

3
.
Connect
an
ammeter
and
an
insulated
jumper
wire
be-

tween
terminals
in
connector
and
corresponding
pump

terminals
.
See
Fig
.
12
.

FUEL
PUMP

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
.

8
.
Disconnect
main
harness
connector
from
transmission

by
turning
its
bayonet
lock
ring
counterclockwise
.
Re-

move
wiring
harness
from
transmission
housing
.
See
Fig
.
8
.

Fig
.
8
.



Harness
connector
at
automatic
transmission
.

9
.
Where
applicable,
disconnect
harness
connector
from

speed
sensor
at
top
óf
transmission
.

10
.
Disconnect
transmission
cooler
line
clamps
from
en-

gine
.
Disconnect
lines
from
transmission
.

11
.
Support
transmission
with
transmission
jack
.
Remove

reinforcing
cross
brace
(if
applicable)
and
transmission

support
crossmember
.

NOTE-

Note
installation
positionof
support
crossmember
.

12
.
Remove
access
plug
in
cover
plate
on
right
side
of
en-

gine
block
and
remove
torqueconverter
bolts
.
Turn

crankshaft
to
access
boits
.
See
Fig
.
9
.

AUTOMATIC
TRANSMISSION



240-
5

Bellhousing
access
hole

Socket
wrench

Fig
.
9
.



Access
andremove
torque
converter
boits
through
hole
in
bellhousing
cover
.

0

A

fij
13
.
Remove
bellhousing-to-engine
mounting
bolts
.
See



Fig
.
10
.
Transmission-to-engine
Torx-head
mounting
bolts
.
Fig
.
10
.

0012592

TRANSMISSION
REMOVAL
AND
INSTALLATION

Fig
.
6
.



Preload
center
bearing
toward
front
4-6
mm
(arrow)
.

5331
5
.
Tightenthreadedsleeveondriveshafttopropertorque
.

6
.
Insta¡¡
heat
shield
and
heat
shield
crossmember
.

Tightening
Torques

"
Driveshaftcenter
mount
to
body
.
.
..
21
Nm
(16
ft-Ib)

"
Driveshaft
clamping
sleeve
.....
.
.
.
10
Nm
(89
in-lb)

"
Driveshaft
to
final
drive
flange

With
CV
joint
(M8)
............
...
32
Nm
(23
ft-Ib)

Wth
U-joint
(M10
ribbed
nut)
....
...
80
Nm
(59
ft-Ib)

With
U-joint
(M10
compressed
nut)
..
60
Nm
(44
ft-Ib)

"
Flex-disc
to
driveshaft
or
transmissionflange

M10
(8.8
grade)
.........
.
....
..
.
48
Nm
(35
ft-Ib)

M10
(10
.9
grade)
........
.
....
...
64
Nm
(47
ft-Ib)

M12
(8.8
grade)
........
.....
..
.
.
81
Nm
(60
ft-Ib)

M12
(10
.9
grade)
.
.
....
......
...
100
Nm
(74
ft-Ib)

M12
(10
.9
grade)
(M3
models)
..
.
.
.
115
Nm
(85
ft-Ib)

"
Transmission
crossmember

to
body
(M8)
.
....
...........
....
21
Nm
(16
ft-Ib)

NOTE-

Bolt
grade
is
markedon
the
bolt
head
.
When
replacing
bolts,
only
use
bolts
of
the
same
strength
and
hardnessas
the
originalsinstalled
.

Flex-disc,
replacing

The
flex-disc
between
the
front
section
of
the
driveshaft
and

theoutputflange
of
the
transmission
should
be
checked
for

cracks,
tears,
missing
pieces,
or
distortion
.
Check
for
worn
bolt
hole
bores
in
theflange
.

1
.
Remove
driveshaft
as
described
in
Driveshaft,
remov-
ing
.

NOTE-

¡t
is
possible
to
only
partially
remove
the
driveshaft,
leaving
it
connected
to
the
final
drive
.
The
driveshaft
canbe
tilted
down
in
thecenter
and
slidoff
the
trans-
mission
flange
once
the
clamping
sleeve
is
loosened
and
the
center
bearing
bracket
is
unbolted
.
Suspend
the
driveshaft
using
stiff
wire
in
as
close
to
the
installed
position
as
possible
.
If
the
driveshaft
hangs
unsupport-
ed,
the
rear
universal
joint
may
be
damaged
.

2
.
Unbolt
flex-dísc
from
driveshaft
.

DRIVESHAFT
260-
5

7
.
Install
exhaust
system
.
See
180
Exhaust
System
.

Connect
wiring
harness
to
oxygen
sensors
.



NOTE-

Removaland
installation
of
the
boltsmaybe
made
eas-
8
.
Road
test
vehicle
to
check
for
noiseor
vibration
.



ier
by
placing
a
large
hose
clamp
around
the
flex-disc,
and
tightening
the
clamp
slightlyto
compress
the
cou

WARNING
-



pling
.

"
Do
not
reuse
self-locking
nuts
.
These
nuts
aredesigned
to
beused
only
once
.



3
.
Insta¡¡
new
flex-disc
using
new
self-locking
nuts
.
Mold-

"
Avóid
stressing
the
flex-disc
when
torquing
the



ed
arrows
on
coupling
should
face
flange
arms
.
See

bolts
Do
this



holding
the
bolts



Fig
.
7
.
steady
and
.



uy
turning
the
nuts
on
theflange
side
.

5
:132

Fig
.
7
.



When
attaching
flex-disc,
molded
arrows
must
point
toward

flange
arms
.

DRIVESHAFT
SERVICE

340-
1
2
BRAKES

ABS
is
self-tested
by
the
ABS
diagnostic
unit
each
time
the
car
is
started
.
Once
the
test
is
complete,
the
ABS
dashboard
light
tucos
off
.
If
the
light
remains
lit
or
comes
on
at
any
time
during
driving,
a
system
fault
has
occurred
and
ABS
is
elec-
tronically
disabled
.
The
conventional
braking
systemremains
fully
functioning
.

ABS
Inspection

A
visual
inspection
of
the
ABS
may
help
to
locate
system
faults
.
If
no
visual
faults
can
befound
and
the
ABS
light
re-
mains
on,
have
the
system
diagnosedbyan
authorized
BMW
dealer
.

Carefully
inspect
the
entire
ABS
wiring
harness,
particularly

the
pulse
sensorharnesses
and
connectors
near
each
wheel
.

Look
for
chafing
or
damage
due
to
incorrectly
routed
wires
.

Carefully
remove
the
wheelspeed
sensors
.
Clean
the
sen-



Fig
.
18
.
Front
ABS
pulse
sensor
mounting
bolt
(arrow)
.
sor
tips
.
Inspect
the
toothed
wheel
on
thewheel
hub
.
Check
for
missing,
clogged
or
corroded
teeth,
or
other
damage
that
could
alter
the
clearance
between
the
sensor
tip
and
the
toothed
wheel
.

NOTE-

If
a
toothed
ring
is
damaged,
the
entire
wheel
hub
mustbe
reptaced
.
See
310
Front
Suspension
or330
Rear
Suspension
.

ABS
wheel
speed
sensors,
replacing

1
.
Raise
applicable
end
of
car
.

WARNING
-

Make
sure
thecar
is
firmly
supportedon
jack
stands
designed
for
the
purpose
.
Place
the
jack
stands
be-
neath
a
structural
chassis
point
Do
not
place
jack
stands
under
suspension
parts
.

2
.
Unscrew
wheelspeed
sensor
mounting
bolt
.
Remove
sensor
from
its
housing
.
See
Fig
.
18
.
Remove
harnessfrom
retaining
mounts
.

3
.
Front
ABS
sensor
:
Working
in
front
wheel
housing,
dis-
connect
and
remove
sensor
.
See
Fig
.
19
.

4
.
Rear
ABS
sensor
:
Working
in
rear
wheel
housing,
dis-
connect
andremove
sensor
.

5
.
During
installation,
apply
thin
coat
of
Molykote
0
Long-
term
2
or
an
equivalent
grease
to
pulse
sensor
and
housing
.

ANTILOCK
BRAKE
SYSTEM
(ABS)

0012122
Fig
.
19
.
Front
ABS
wheel
speed
electrical
connector
(arrow)
in
wheel
well
.

6
.
Installation
is
reverse
of
removal
.