1995 BMW 318i Engine management

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
.

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
©©®®17
©©®©©~©©®©~~rui~~ru

®®®®®®®®®®®®®®®IZA®®®®®®®®®®®®®®®®®

1
>I-
0013211

ECM
PIN
ASSIGNMENTS

170-2



RADIATOR
AND
COOLING
SYSTEM

Cooling
Fans



TROUBLESHOOTING

Belt-driven
coolingfan
.
The
primary
cooling
fan
is
belt-

driven
.
It
is
mounted
to
the
frontof
the
coolant
pump
through
a

fan
clutch
.
The
fan
clutch
is
a
viscous
fluid
coupling
that
con-

trols
the
speed
of
thefan
based
on
engine
compartment
tem-

perature
.

Electric
cooling
fan
.
Models
with
M44
engine
and
stan-

dard
transmission
substitute
an
electric
fan
for
the
belt-driven

viscous
fan
.
This
is
attached
to
the
rear
of
the
radiator
and

controlledvia
the
DME
5
.2
engine
management
system
.

NOTE-

The
electric
cooling
fan
in
these
models
is
activated
by
the
engine
control
module
(ECM)
.

Auxiliary
coolingfan
.
In
al¡
models
a
two-speed
electric

auxiliary
cooling
fan
is
mounted
behind
the
front
grill
and
in

front
of
the
radiator
.
This
fan
is
primarily
used
for
the
A/C
sys-

tem,
but
also
operates
when
the
coolant
temperature
ex-

ceeds
a
predetermined
leve¡
.

Warnings
and
Cautions

The
following
warnings
and
Cautions
should
beobserved

when
working
on
the
cooling
system
.

WARNING
-

"
Atnormal
operating
temperature
the
cooling
sys-
tem
is
pressurized
.
Allow
the
system
to
cool
as
long
as
possible
before
opening-a
minimum
of
an
hour-then
release
the
cap
slowly
to
allow
sale
release
of
pressure
.

"
Releasing
the
cooling
system
pressure
lowers
the
coolants
boiling
point
and
the
coolant
may
boíl
suddenly
.
Use
heavy
gloves
and
wear
eye
and
laceprotection
to
guard
against
scalding
.

"
Use
extreme
care
when
draining
and
disposing
of
engine
coolant
.
Coolant
is
poisonous
and
lethal
to
humans
and
pets
.
Pets
are
attracted
to
coolant
because
of
its
sweet
smell
and
taste
.
Consult
a
veterinarian
immediately
if
coolant
is
ingested
byan
animal
.

CAUTION-

"
Avoidadding
cold
water
to
the
coolant
while
the
engine
is
hot
or
overheated
.
If
it
is
necessary
to
add
coolant
to
ahot
system,
do
so
only
with
the
engine
running
and
coolant
pump
tuming
.

"
Prior
to
disconnecting
the
battery,
read
the
bat-
tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.

TROUBLESHOOTING

Most
cooling
system
faults
can
be
grouped
into
one
of
three

categories
:

"
Cooling
system
leaks

"
Poor
coolant
circulation

"
Radiator
cooling
fan
faults

When
investigating
the
cause
of
overheating
or
coolant

loss,
begin
with
a
visual
inspection
.
Be
sure
to
check
the
con-

dition
and
tension
of
the
coolant
pump
drive
belt
.
Check
hoses

for
cracks
or
softness
.
Check
clamps
for
looseness
.
Check

the
coolant
leve¡
and
check
for
evidence
of
coolantleaks
from

the
engine
.

Check
that
the
radiator
fins
are
not
blocked
with
dirt
or
de-

bris
.
Clean
the
radiator
using
low-pressure
water
or
com-

pressed
air
.
Blow
outward,
fromthe
engine
side
out
.

Inspect
the
coolant
pump
by
first
removing
the
drive
belt

from
the
pump
.
Firmly
grasp
opposite
sídes
of
the
pulley
and

check
for
play
in
all
directions
.
Spin
the
pulley
and
check
that

the
shaft
runs
smoothly
.

NOTE-

The
coolant
provides
lubrication
for
the
pump
shaft,
soan
occasional
drop
of
coolant
leaking
from
the
pump
is
acceptable
.
If
coolant
drips
steadily
from
the
vent
hole,
the
pump
should
be
replaced
.

The
cooling
system
becomes
pressurized
at
normal
operat-

ing
temperature,
which
raises
the
boiling
point
of
the
coolant
.

Leaks
may
prevent
the
system
from
becoming
pressurized,

allowing
the
coolant
to
boil
at
a
lower
temperature
.
If
visual
ev-

idence
is
inconclusive,
a
cooling
system
pressure
test
can

help
to
pinpointhard-to-find
leaks
.

If
the
cooling
system
is
full
of
coolant
and
holds
pressure,

the
next
most
probable
cause
of
overheating
are
:

"
Faulty
radiator
fan

"
Loose
or
worn
drive
belt

"
Failed
thermostat
or
coolant
pump

"
Clogged/plugged
radiator
or
coolant
passages
.

NOTE
-

"
Some
early
style
coolant
pumps
were
fitted
wíth
fi-
berlplastic
type
impellers
.
Over
time,
this
impeller
can
wear
away
and
result
in
overheating
.
The
plastic
im-
peller
can
also
slip
or
free-wheel
on
the
pump
shaft
.
If
the
engine
overheats
and
no
other
faults
canbe
found,
theold
style
impeller
may
be
the
cause
of
the
problem
.

"
Only
pumps
with
the
updated
metal
impeller
should
be
used
for
replacement
.

300-4



SUSPENSION,
STEERING
AND
BRAKES-GENERAL

Three-channel
ABS
ís
used
on
al[
E36
cars
equipped
with



Al¡
Season
Traction
(AST)
standard
ABS
.
Each
front
wheelhas
a
separate
solenoid

valve
to
modulate
hydraulic
pressure
to
that
brake
caliper
.



The
traction
control
system
works
in
conjunction
with
ABS
The
rear
wheels
are
modulated
asa
pair,
controlled
by
a
sin-



and
the
engine
management
system
to
enhance
vehicle
con
gle
solenoid
valve
.



trol
.
The
main
function
of
the
AST
system
is
to
maintain
the
rolling

contact
between
the
tires
and
the
road
surface
under
al¡
driving
E36
cars
equipped
with
ABS/AST
utilize
a
four
channel
sys-



conditions
.
This
is
achieved
through
exact
application
and
tem,
which
functionsexactly
as
the
three
channelsystem



management
of
braking
and
drivetrain
forces
.
above,except
that
the
rear
wheels
are
modulated
individually
.

IDLE
SPEED
CONTROL
VALVE

HROTTLE
PLATE

6
.

Í
III

i



ADS
ACTU
AT
OR

THROTTLE
PLATE
POSITION
SENSOR

DME

Fig
.
6
.
All
Season
Traction
(AS)
works
withother
drivetrain
systems
to
enhance
vehicle
control
.

INTEGRATED
SYSTEMS

The
throttle
control
system
used
in
AST
is
illustrated
in
Fig
.

MASS
AIR
FLOW
SENSOR

JADS
THROTTLE
PLATE
POSITION
SENSOR

0013006

GENERAL

This
section
contains
wiring
diagrams
for
1992
through

1998
BMW
3
Series
models
.

WARNING
-

On
cars
equipped
with
airbags,
special
precautions
apply
to
any
electrical
testing
or
repair
.
The
airbag
unit
is
an
explosive
device
and
must
be
handled
with
exterme
care
.
Before
starting
any
work
onan
airbag
equipped
car,
refer
to
the
warnings
and
cau-
tions
in
720
Seatbelts
and
721
Airbag
Systems
(SRS)
.

NOTE-

The
"



gear
position/neutral
safetyswitch
is
also
some-
timesreferred
to
as
the
automatic
transmission
range
switch
.

"
The
EWS
11
system
is
also
sometimes
referred
to
as
the
Driveaway
Protection
System
or
the
electronic
im-
mobilization
system
.

ELECTRICAL
WIRING
DIAGRAMS



ELE-1

Electrical
Wiring
Diagrams

GENERAL
.
.
.
.
.
.
.
.
.
................
.
.
.
ELE-1



Horns



.....
.
.....
.
.
.
....
.
.
.
.
.
...
.
.
ELE-153

Instrument
Panel
.
.
.
.
.
.
..............
ELE-165

ELECTRICAL
WIRING
DIAGRAMS
...
.
.
.
ELE-2



Interior
Lights/Illumination
.............
ELE-211

ABS



..............
.
.
.
.....
.
.....
ELE-117



Lumbar
Control
.
....................
ELE-247

ABS/AST
.............
.
.
.
...
.
.
.
.....
ELE-120



On-Board
Computer
..................
ELE-173

Airbag
(Supplemental
Restraint
System)
..
ELE-140



Park
Ventilation
.
.
.
...........
.
...
.
..
ELE-139

Air
Conditioning
and
Heating
.
.
.
.
.
.
.....
ELE-129



Power
Distribution
......
.
...
.
.
.
.
.
.
.
...
.
ELE-2

Anti-Theft
(Alpine)
..........
.
.
.
...
.
...
ELE-144



Power
Door
Locks
.
.
......
.
.
.
.
.
.
.
.
.
..
ELE-226

Anti-Theft
(EWS
II)
.
........
.
.
.
...
.
...
ELE-150



Power
Mirrors
...
.
.
.
......
.
.
.
.
.
.
.
.
.
..
ELE-241

Body
Computer
Module
.....
.
.....
.
...
ELE-176



Power
Seats
......
.
......
.
.
.
...
.
.
.
..
ELE-243

Charging
System



.
.
................
.
.
.
ELE-67



Power
Sunroof
.
.
.
.
.
.
.
...............
ELE-248

Convertible
Top
.
.
.
.
................
.
.
ELE-253



Power
Windows
.
.
.
.
.
.
.....
.
.........
ELE-231

Cruise
Control
..
.
.
.
...........
.
....
.
.
ELE-112



Radio/Cassette/CD/Speakers
..........
ELE-255

Data
Link
Connector
................
.
.
.
ELE-86



Rear
Window
Defogger
...............
ELE-160

Engine
Cooling
.......
.
.......
.
....
.
.
.
ELE-94



Shift
Interlock
.
.
.
.
.
.
.
.
...............
ELE-110

Engine
Management
...
.
.......
.
....
.
.
.
ELE-70



Starting
....
.
.
.
.
.
...
.
................
ELE-63

Exterior
Lights
........
.
.
.
.
.
.
.
.
.
......
ELE-194



Transmission
Electronics
.
..............
ELE-96
Ground
Distribution
....
.
.
.
.
.
.
.
.
.
.......
ELE-35



Warning
System
:
Chimes
.............
ELE-178

Headlights/Foglights
...
.
.
.
.
.
.
.
.
.
......
ELE-180



Wiper/Washer
.
.....
.
...............
ELE-155

Heated
Seats
........
.
.
.
.
.
.
.
.
.
......
ELE-245

ELECTRICAL
COMPONENT
LOCATIONS

Relayand
fuse
positions,
ground
locations
...........
.
.
.
.
.
.
.
.
.
................
seeRepair
Group
610

CAUTION-

Always
switchthe
ignition
off
and
disconnect
the
negative
(-)
battery
cablebefore
removing
any
electrical
components
.

"
Prior
to
disconnecting
the
battery,
read
the
bat-tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.

"
Connect
and
disconnect
ignition
system
wires,
multiple
connectors
and
ignition
test
equipment
leads
only
while
ignition
is
switched
off
.

-Always
switch
a
test
meter
to
the
appropiate
func-
tion
and
range
before
making
test
connections
.

"
All-Season
Traction
(AST)
is
also
referred
to
as
ASC
or
ASC+T
.

GENERAL

ELE-70
ELECTRICAL
WIRING
DIAGRAMS

I



02
SENS
SIB
I"7
7
I
02SENSGNDI)
I



GROUNDI
2



BR
,
'IB
BRN/BLU
I
IARCVALVEI
I
IsCVALVEI}
I



ECM
RELAY
I
EEVALVEI~
I
CVL4IGNCOILI
S7~LK
I



CVL3IGNCOILI
24L
BL1(

I



CVL2IGN
COILI'
B2
~
BLK
I
CVLIIGNCOILI
2
I



GROUNDI
B'=RN
I
GF
.uNDI
),
BRN
I



GROUNOI
3~
BR"
I
RUNIST
GRN
ARTI
S~
ENGINECONTROL
MODULE
(DME)

13B
START



1
GRN
I
DN

OFF
IGNITION
S
WITCH

8727
3

HOTATALLTIMES

UELINJECTION
VALVES

NCA"
=
It,
INCA
SPIN

BRN
GRN
~GRN
OF
N



/



GRN"
\
GRN

Engine
Management

19921
.8L
(1
of
2)

HOTAT
F4
X3X2
R1



ALLTIMES
I
XZ793
M
M
[]M[IM



AT
.
LINK
CONNECTOR
8B
3Dy
eB=85
.1
.1308
I

ii



w
>
3~

3

3
BRNIWH
INJCTRLI
32
BRNIYEL
T
INJCTRLI~
DLCI
je7



L



REO
I
RED
BATTERY
I
2S



RED



RED

FRONT_POWERDISTRIBUTIONBO%
_
_
___
_
_
_
____
_
_
I



ENGINE
CONTROL
MODULE
RELAY



FUEL
PUMP
RELAY

L

ECMFLY
CTRL
1)27



BFN
FP
FLY
CTRL
I
I'



SWORN
02SFLYCTRL
I
37



BRNIGRN



BRN
GRN
DLCI
80
GRNIBLU
RE
O
DLCI
,88



WHTIVIO

1
~1~

2oY
1
Y
I4Y
_
i
2Y
SY
BX
BY
4YBY

EVAPORATIVE



IDLESPEED



INTAKE
AIR
EMISSION
CONTROL
RESONANCE
VALVE



VALVE



CHANGEOVER
VALVE

8727
4

FRONT
_TPOWER
ER_DIS_TR_IBUTION
BOX
FHOTIN



OXYOENSE_NSORRE_LA
_Y



I
I
RUNAND



I
GRN/VIO
16
START



I
X,
DD>
6



I

GRNIV10GRN/VIO
BRNIGRNRED/WHT
BLK
YELBLK
BRN/ORG

I
U
E



1185-T86



13D
18,
6A



4Y



BY



6Y



2Y

-
,T,
F
E37017

IL



I



L-
I
--!



!
NORMAL



PRESSURE
SPEEDRELAY



SWITCH

G

ELECTRICAL
WIRING
DIAGRAMS
ELE-71

Engine
Management

19921
.8L
(2
of
2)

INTEGRATED
CLIMATE
HEATEDOXYGEN
CRANKSHAFT
CAMSHAFT



REGULATION
SENSOR
POSITION/RPM
POSITION
CONTROLMODULE
SENSOR
SENSOR

I



I

a



<



I
X181
.58
1
X
18185
UV
U



~



22



2



2



2



F



',-



~



F



~



_
_
_
_
vvvv



I
-
tt
i

2



I



I



I



1



I



1



__



r
-
I



.I



r
-
-
I



I



I



1



BLKIWHT
2
"
~~{I
VEHICLE
SPEED
GRN



I



1



1



1
zlzl



1



1



zl



1



1



1



.
.1



1



I



X17
(
OUTPUT
WHT/BLK
21
I
FUEL
%ifi
(CONSUMPTION

BRN/BL
/BL

CYL(-2



CYL3-4



ENGINECOOLANT
KNOCK



KNOCK



TEMPERATURESENSOR



SENSOR



SENSOR

>I



BLK
20
'EN
.IMEBPEE
.
1



INPUT

I



II
SERVICE
II
REMINDER
I
I
INDICATOR
I
GRG~
~
I
X1fi
I

INSTRUMENT
WlON-BOARD
CLUSTER
COMPUTER

Ks
w-HT/B~~
-
"



BLK~VIO
lI



I
i
ON-BOARD
COMPUTER

BLKIVIO
81
r



I
CIOBCOMP
I
WHT/BLK
17
LK/WHT
T3CIFCINPUT



I
B
{IVSOUTPUT
I
ORY
IENGINDICAT0R
I
BLK
74
,
1ESINPUT



I
VIOIGRV
B6
IICRCMOD
I
Y
EL
SLK



1B



I
CAM
SENS
SIG
B
44,
I
CAM8ETURN
BLK
BB
CPS
SIG
yEL



"'
BLK/



I
CPS
RETURN
PRESSSWITCH
-
B



I
BRN/B
ICYLI-2KS
(SHIELD--------

BRN/RED
78



ICYL3-4
K5
IECTSENS

GRYIWHTB



59~ITPSINPUT
ITPSSENSOR
G
I,VAFSENSOR
GRY/YEL
41
(
_



IVAFSENSOR
GRY/SLU
14
~
I
INTEMP
SENS
GRYRYIV
~INTEMPSENS

GRYIVIO
4
GRY/BLU
6
GRY/WHT
1

GRYIYEL
2

GRY/BLK
3

GRY/WHT
1
SRN
2
BRN/BLK
3

ENGINECONTROL
MODULE
(OME)

VOLUMEAIR
FLOW
SENSOR

THROTTLE
POSITION
SENSOR