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
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
.
2
.
Remove
fuel
tank
filler
cap
.
3
.
Remove
rearseat
cushion
and
pull
back
insulation
mats
to
expose
fuel
tank
access
covers
.
See
Fig
.
2
.
uui3140
Fig
.
2
.
Right
side
fuel
tank
access
cover
under
rear
seat
cushion
.
4
.
Remove
right
and
left
access
covers
to
expose
fuel
hoses
and
electrical
connections
at
tank
.
5
.
Label
fuel
hoses
.
Then
disconnect
hoses
and
harness
connectors
from
fuel
sending
units
and
fuel
pump
.
See
Fig
.
3
.
FUELTANK
AND
FUEL
PUMP
160-
3
NOTE-
"
If
necessary,
push
fuel
level
sender
arm
toward
fuel
pump
assembly
to
facilitate
removal
.
"
BMW
special
tool
no
.
16
1
020
should
beused
tore-
move
and
install
the
threaded
collar
.
Damage
to
thecollar
may
result
if
the
special
tool
is
not
used
.
"
Pump
out
contents
of
each
tanklobe
using
approved
pumpinglextraction
equipment
and
flexible
fuel-grade
hose
.
WARNING
-
Fuel
may
be
spilled
.
Do
not
smoke
or
work
near
heaters
or
other
fire
hazards
.
7
.
Installation
of
sending
units
is
reverse
of
removal,
not-
ing
the
following
:
"
Use
new
sealing
rings
when
installing
pump/sending
unit
assemblies
.
"
Be
sure
that
fuel
line
connections
point
in
same
direc-tion
as
they
carne
out
.
"
Fill
tank
and
check
for
leaks
by
running
engine
.
CA
UTION-
Before
starting
the
engine,
fill
the
fuel
tank
with
at
least
1.5
gallons
(5liters)
of
fuel
.
The
pump
will
be
damaged
if
you
run
it
without
fuel
.
Fuel
tank,
removing
and
installing
1.
Disconnect
negative
(-)cablefrom
battery
:
CAUTION-
Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
viii
.
2
.
Remove
fuel
tank
filler
capand
drain
tank
as
described
earlier
.
3
.
Working
in
left
access
tank
access
hole
(under
rear
seat
cushion),
remove
vent
pipe
fromtank
.
4
.
Working
inside
car,
disconnectparking
brake
cable
ends
from
parking
brake
lever
.
See
340
Brakes
.
5
.
Working
underneath
car,
gently
pry
fuel
lines
away
from
retaining
bracket
in
front
of
tank
.
Remove
clamps
and
disconnect
fuel
hoses
as
shown
in
Fig
.
4
.
6
.
Remove
exhaust
system
and
heat
shield
as
described
ooisiai
in
180
Exhaust
System
.
See
Fig
.
5
.
Fig
.
3
.
Fuel
pump/fuel
level
sender
assembly
in
top
offuel
tank
(right
side
shown)
.
Disconnect
supply
hose
(A),
return
hose
(B)
and
7
.
Remove
driveshaft
.
See
260
Driveshaft
.
harness
connector
(C)
.
8
.
Pull
parking
brake
cables
backward
away
from
bottom
of
6
.
Unscrew
threaded
collars
from
fuel
tank
.
Slowly
with-
fuel
tank,
disengaging
them
from
brackets
as
needed
.
draw
fuel
sender
assemblies
from
tank,allowing
fuel
to
drain
off
.
FUEL
TANKAND
LINES
160-
4
FUEL
TANK
AND
FUEL
PUMP
Fig
.
4
.
Pinch
off
supply
and
retum
fuel
hoses
(arrows)
before
dis-
connecting
from
rigid
metal
lines
.
0013143
Fig
.
5
.
After
removing
exhaustsystem,
remove
heat
shield
screws
(arrows)
and
heat
shield
.
9
.
Working
underneath
car,
loosen
hose
clamp
and
dis-
connect
filler
hose
.
10
.
Support
tank
from
below
.
Remove
tank
strap
mounting
bolts
.
Lower
and
remove
tank,
disconnecting
right
side
TheE36
model
uses
a
two-lobed
fuel
tank
and
each
lobeof
vent
and
other
hoses/electrical
connectors
as
neces-
the
tank
has
its
own
fuel
level
sending
unit
.
sary
.
11
.
Installation
is
reverse
of
removal
.
"
Always
use
new
seals,
gaskets,
O-rings,
and
hose
clamps
.
"
Inspect
hoses
and
replace
any
that
are
chafed,
dried
outor
cracked
.
"
Inspect
heat
shield
and
replace
if
corroded
.
"
Inspect
rubber
buffers
and
liners
on
fuel
tank,
support
straps
and
on
underside
of
body
.
Replace
rubber
parts
that
are
hardened
or
damaged
.
FUEL
LEVEL
SENDERS
CAUTION-
"
Before
starting
the
engine,
fill
the
fuel
tank
with
at
least
1.5
gallons
(5
liters)
of
fuel
to
prevent
damaging
a
dry
fuel
pump
.
"
If
the
filler
neck
has
been
removed
from
the
body,
be
sure
toreattach
theneck's
grounding
screw
(where
applicable)
.
Check
electrical
resistance
between
the
ground
tab
and
wheel
hub
.
The
re-
sistance
shouldbeno
higher
than
0
.6
ohms
.
Tightening
Torques
"
Fuel
tank
to
body
.............
...
23
Nm
(17
ft-Ib)
"
Hose
clamps
(10
mm-16
mm
día
.)
..
2
.0
Nm
(18
in-lb)
Fuel
Tank
Evaporative
Control
System
The
fuel
tank
evaporative
control
system
is
used
to
vent
the
fuel
tank
to
a
charcoal
canister,
which
is
then
purgedby
en-
gine
vacuum
during
normal
engine
operatíon
.
This
controls
emission
of
raw
hydrocarbons
(fuel)
to
the
atmosphere
.
See
Fig
.
1
.
A
fuel
expansion
tank,
located
under
the
right
rear
fender,
traps
overflow
fuel
and
incorporates
extra
fuel
tank
plumbing
.
Startingwith
1996
models,
OBD
II
standards
require
that
the
fuel
tank
evaporative
control
system
be
monitored
for
leaks
.
This
is
accomplished
usingthe
fuel
tankpressuresen-
sor,
the
ventshut
off
valve,
and
the
evaporative
purge
valve
.
NOTE-
On
most
early
cars(1992-1995),
the
charcoal
canister
is
in
the
engine
compartment
.
On
latercars,
the
char-
coal
canister
is
under
the
spare
tire
in
the
luggage
com-
partment
.
FUEL
LEVEL
SENDERS
The
right
side
fuel
leve¡
sender
is
integrated
with
the
fuel
pump
.
Each
senderhas
a
float
connected
to
a
variable
resis-
tance
for
fuel
leve¡
.
When
replacing
the
sender/pump
assem-
bly
always
replace
hose
clamps,gaskets
and
O-rings
.
WARNING
-
When
removing
the
fuel
level
sender
or
the
fuel
pump,
the
fuel
tank
should
be
emptied
.
5
.
Slowly
add
coolant
until
it
spills
from
bleed
screws
.
When
coolant
spillíng
from
bleed
screws
is
free
of
air
bubbies,
tighten
screws
.
6
.
Run
engine
until
it
reaches
operatíng
temperature
.
Af-
ter
engine
has
cooled,
recheck
coolant
level
and
top
up
as
necessary
.
CAUTION-
Always
use
genuine
BMW
coolant
or
its
equiva-
lent
to
avoid
the
formation
of
harmful,
clogging
de-
posits
in
the
cooling
system
.
Use
of
other
antifreeze
solutions
may
be
harmful
to
the
cooling
system
.
Tightening
Torque
"
Radiator
bleed
screw
to
thermostat
housing
...
.
.
........
8
Nm
(71
in-lb)
Belt-driven
cooling
fan,
replacing
1
.
Usinga32
mm
wrench
on
fan
clutch
nut,
turn
wrench
quickly
in
a
clockwise
direction
(working
from
front
of
car)
to
loosen
.
Spin
fan
off
pump
.
See
Fig
.
8
.
NOTE-
"
The
radiator
cooling
fan
nut(32
mm
wrench)
has
left-
hand
threads
.
"
The
nut
may
be
difficult
to
loosen
.
Use
a
tool
to
hold
the
coolant
pump
pulleystationary
.
BMW
hasa
spe-
cial
tool
forthis
purpose
(BMW
special
tool
no
.
115
030)
.
2
.
Remove
expansion
rivets
holding
shroud
to
radiator
.
See
Fig
.
9
.
Remove
fan
and
shroud
together
.
NOTE-
Store
the
removed
fan
clutch
assembly
in
an
upright
(installed)
positionto
prevent
lossof
clutch
fluid
.
RADIATOR
AND
COOLING
SYSTEM
170-
7
Fig
.
8
.
Radiatorcooling
fannut
(arrow)
.
Nuthas
left-hand
threads
.
3
.
To
replace
fan
clutch,
remove
fan
mounting
bolts
and
separate
clutch
from
fan
.
Fig
.
9
.
Fan
shroud
retaining
rivet
(arrow)
.
Pryout
center
pin
and
re
4
.
Installation
is
reverse
of
rernoval
.
move
rivet
.
Rivet
design
may
vary
depending
on
model
and
model
year
.
Tightening
Torques
"
Clutchnut
to
coolant
pump
(left-hand
threads)
Wíthout
BMW
tool
no
.
11
5
040
.....
40
Nm
(29
ft-lb)
With
BMW
tool
no
.
11
5
040
.
......
30
Nm
(22
ft-Ib)
"
Fan
to
viscous
clutch
...
.
..
.
......
10
Nm
(89
in-lb)
0013203
COOLING
SYSTEM
SERVICE
170-8
RADIATOR
AND
COOLING
SYSTEM
Electric
cooling
fan,
replacing
On
late
4-cylinder
models
(M44
engine)
with
manual
trans-
mission,
the
primary
cooling
fan
is
electrically
operated
and
is
mounted
on
the
engine
side
of
the
radiator
.
1
.
If
necessary,
remove
cover
from
top
of
radiator
.
See
Fig
.
10
.
0012505
Fig
.
10
.
Air
cover
in
back
of
radiator
.
Unclip
cover
from
fan
shroud
af-
ter
removing
mounting
screws
.
2
.
Disconnect
fan
harness
connector
at
bottom
left
of
ra-
diator
.
3
.
Remove
fan
shroud
mountingscrews
at
left
and
right
side
of
radiator
.
Lift
fan
assembly
straight
up
and
offra-
diator
.
4
.
Installation
is
reverse
of
removal
.
Be
sure
to
align
side
tabs
on
fan
housíng
with
retaining
tabs
on
radiator
when
reinstalling
fan
.
Auxiliary
cooling
fan,
replacing
The
auxiliary
electric
cooling
fan
is
mounted
behind
the
front
bumper,
in
front
of
the
A/C
condenser
.
There
aretwo
ver-
sions
of
auxiliary
fans
installed,
depending
on
model
and
en-
gine
installed
.
TType
1
(u
p
to
9192)
1
.
Remove
front
radiator
air
shroud
.
See
Fig
.
11
.
2
.
Remove
fan
mountingscrews
.
See
Fig
.
12
.
3
.
Tilt
fan
forward
.
Disconnect
electrical
harness
connec-
tor
before
lifting
fan
up
.
COOLING
SYSTEM
SERVICE
Fig
.
11
.
Front
radiator
air
shroud
fasteners
(arrows)
.
Fig
.
12
.
Version
1
auxiliary
fan
mountingscrews
(arrows)
.
NOTE
-
If
necessary,
remove
front
bumper
or
lowerengine
cov-
erto
access
electrical
harnessconnector
.
4
.
Installation
is
reverse
of
removal
.
l)
Type
2
(from
9192)
2
.
Remove
fan
mounting
screws
.
See
Fig
.
13
.
0013137
1.
Remove
front
bumper
and
radiator
grilles
.
See
510
Ex-
terior
Trim,
Bumpers
.
3
.
Angle
fan
up
and
forward,
disconnecting
electrical
har-
nessconnectorbehind
it
.
Remove
it
through
bumper
opening
.
Fig
.
13
.
Version
2
auxiliary
fan
mounting
screws
(arrows)
.
Front
bumper
hasbeen
removed
.
4
.
Installation
is
reverse
of
removal
.
Thermostat,
replacing
0013146
The
coolant
thermostat
is
instalied
in
a
housing
at
the
front
of
the
cylinder
head
.
See
Fig
.
14
.
Fig
.
14
.
Coolantthermostat
and
housíng
.
NOTE-
On
M44
engines,
the
thermostat
is
integrated
into
the
thermostat
housíng
.
If
the
thermostat
requiresreplace-
ment,
the
complete
thermostathousing
mustbe
replaced
.
RADIATOR
AND
COOLING
SYSTEM
170-
9
WARNING
-
Allow
the
cooling
system
to
cool
before
opening
ordraining
the
system
.
2
.
Remove
belt-driven
cooling
fan
and
fan
shroudas
de-
scribed
earlier
.
3
.
On
M52/S52US
engines
:
Unclip
wiring
duct
retaining
clips
and
remove
duct
from
above
thermostat
housing
.
Also
remove
engine
front
lifting
bracket
.
4
.
Remove
thermostat
housing
from
front
of
engine
.
See
Fig
.
15
.
Fig
.
15
.
Thermostat
housíng
shown
removed
(6-cylinder
engine)
.
NOTE-
Some
thermostats
have
a
direction
arrowor
venthole
near
the
edge
.
Install
the
thermostat
so
that
either
the
arrow
or
hole
are
at
thetop
.
CAUTION
-
Be
sure
to
reconnect
ground
wire(s)
at
thermostat
housing
mounting
bolt,
where
applicable
.
5
.
Remove
thermostat
.
Note
thermostat
direction
and
ori-
entation
before
removing
.
6
.
Insta¡¡
new
thermostat
and/or
thermostat
housing
using
new
O-ring
and
gasket(s)
as
necessary
.
oo131ss
7
.
Installation
is
reverseof
removal
.
Fill
system
with
cool-
ant
as
described
under
Coolant,draining
and
filling
.
Tightening
Torques
1
.
Drain
radiator
as
described
above
under
Coolant,
"
Thermostat
housing
cover
draining
and
filling
.
to
housing
orcoolant
pump
..
..
....
10
Nm
(89
in-lb)
"
Engine
lifting
bracket
bolt
to
thermostat
housing
(M52/S52US
engine)(M8)
....
..
...
22
Nm
(17
ft-Ib)
COOLING
SYSTEM
SERVICE