1998 BMW M3 OBD connection

GENERAL
.
.....
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.
.
...
100-1

Cylinder
Block
and
Crankshaft
.
.
.
.
.
.
.
.
.
...
100-1

Connecting
Rods
and
Pistons
.
.
.
.
.
.
.
.
.
.
.
.
.
100-1

Cylinder
Head
and
Valvetrain
.
.
.
.
.
.
.
.
.
.
.
.
.
100-2

VANOS
(Variable
Valve
Timing)
.
.
.
.
.
.
.
.
...
100-2

DISA
(Dual
Resonance
Intake
System)
.
.
.
.
.
100-3

Engine
Management
System
.
.
.
.
.
.
.
.
.
.
.
.
.
100-3

Ignition
......
.
.
.
.........
.
.
.
.
.
.
.
.
.
.
.
.
100-5

Fuel
Delivery
..
.
.
.
.....
.
...
.
.
.
.
.
.
.
.
.
.
.
.
100-5

Cooling
System
.
...........
.
.
.
.
.
.....
.
.
100-5

Lubrication
System
.........
.
.
.
.
.
.
.
.
.
.
.
.
100-5

MECHANICALTROUBLESHOOTING
.
.
.
.
100-5

Warnings
and
Cautions
..
.
...
.
.
.
.
.
.
.
.
.
.
.
.
100-5

Cylinder
compression,
checking
.
.
.
.
.
.
.
.
.
.
.
100-6

EngineMechanical
Troubleshooting
Table
.
.
.
100-7

DRIVEABILITY
TROUBLESHOOTING
...
100-8

GENERAL

There
are
various
engíne
configurations
used
in
the
1992-

1998
E36
cars
.
See
Table
a
.

On
both
four-
and
6-cylinder
engines,
the
cylinder
block
is

cast
¡ron
with
integral
cyiinders
.
The
cyiinders
are
exposed
on

all
sides
to
circulating
coolant
.

The
fully
counterweighted
crankshaft
rotates
in
replaceable

split-shell
main
bearings
.
Oiiways
drilled
into
the
crankshaft
pro-

vide
bearing
lubrication
.
O¡I
seals
pressed
into
alloy
sea¡
hous-

ings
are
installedat
both
ends
of
the
crankshaft
.

100
Engine-General

Tablea
.
Engine
Specifications

ENGINE-GENERAL
100-1

On-Board
Diagnostics
(OBD)
...
.
.
.
.
.
.
.
.
.
.
.
100-8

Basic
Requirements
....
.
.
.
...
.
.
.
.
.
....
.100-11

Preventive
Maintenance
......
.
.
.
.
.
.....
100-11

Basic
Engine
Settings
..
.
.....
.
.
.
.
.
.....
100-11

Oxygen
Sensors
.
.
.
...
.
.
.
...
.
.
.
.
.
....
.100-11

Air
Flow
Measurement
and
Vacuum
Leaks
.
.100-12

Battery
Voltage
.
.
...........
.
.
.
.
.
.....
100-12

Wiring
and
Harness
Connections
.
.
.
.
.....
100-13

Ground
Connections
...
.
.....
.
.
.
.
.
.....
100-13

Fue¡
Supply
....
.
...........
.
.
..
.....
.100-14

TABLES

a
.
Engine
Specifications
...
...
...........
.
..
..
.100-1

b
.
Engine
Management
Systems
..
..
...........
..
100-5

c
.
Engine
Mechanical
Troubleshooting
..........
.
.
100-8

d
.
OBD
1
Fault
(Blink)
Codes
(1992-1995
models
only)
.
...
..
..
..........
..
.100-9
e
.
Engine
Driveability
Troubleshooting
...........
.100-15
Model



Engine
code



No
.
of



Dispiacement



Compression



Horsepower
cyiinders



liters
(cu
.
in
.)



ratio



SAE
net
@
rpm

318i/is/¡C
1992-1995



M42



4



1
.8
(109
.6)



10
.0
:1



100
@
6000
1996-1998



M44



4



1
.9
(115
.6)



~
10
.0
:1



103
@
6000

323ís/iC
1998



M52



6



2
.5
(152
.2)



10
.5
:1



168
@
5,500

325i/is/iC
1992-1995



M50



6



2
.5
(152
.2)



10
.0
:1



110
@
5,900

328i/is/iC
1996-1998



M52



6



2
.8
(170
.4)



10
.2
:1



190
@
5,300

M3
1995



S50US



6



3
.0
(182
.5)



10
.5:1



240
@
6,000
1996-1998



S52US



6



3
.2
(192
.3)



10
.5:1



240
@
6,000
Cylinder
Block
and
Crankshaft



Connecting
Rods
and
Pistons

The
forged
connecting
rods
use
replaceable
split-shell

bearings
at
the
crankshaft
endand
solid
bushings
at
the
pis-

ton
pin
end
.
The
pistonsare
of
the
three-ring
typewith
two
up-
per
compression
rings
and
a
lowerone-piece
o¡i
scraper
ring
.

Fui¡-floating
piston
pins
are
retained
with
circlips
.

GENERAL

ignition

Table
b
.
Engine
Management
Systems



engine
has
high
mileage
.

Engine



1
System

4-cylinder
engines
M42
(1992-1995)



Bosch
DME
Ml
.7
M44
(1996-1998)



Bosch
DME
M5
.2
(OBD
II)

6-cylinder
engines
M50
(1992)



Bosch
DME
M3
.1
M50
VANOS
(1993-1995)



Bosch
DME
M3
.3
.1
M52
(1996-1998)



Siemens
MS41
.1
(OBD
II)
S50US
(1995)



Bosch
DME
M3
.3
.1
S52US
(1996-1998)



Siemens
MS41
.1
(OBD
II)

Both
the
4-cylinder
and
6-cylinder
engines
use
a
distributor-

less
ignition
system
with
individual
ignition
coils
for
each
cylin-

der
.

FuelDelivery

Pressurized
fuel
from
the
in-tank
fuel
pump
is
injected
via

solenoid-type
fuel
injectors
.
The
ECM
controls
the
opening

and
closing
of
the
injectors
by
switchingthe
ground
side
of

each
injector
circuit
.
The
exact
amount
of
fuel
injected
is
de-

termined
by
the
amount
of
timethe
injectors
are
open
.

Cooling
System

Whenever
the
engine
is
running,
acoolant
pump
circulates

coolant
through
the
engine
and,
if
either
heater
control
valves

are
open,
through
the
heater
core
in
the
passenger
compart-

ment
.
The
coolant
absorbs
excess
heat
and
carries
it
to
the
ra-

diator
where
it
is
transferred
into
the
passing
airstream
.
A

thermostat
controls
the
flow
of
coolant
through
the
radiator

based
on
engine
temperature
.

Lubrication
System

The
lubrication
system
is
pressurized
whenever
theengine

is
running
.
The
oil
pump
draws
oil
through
a
pickup
in
the
bot-

tom
of
the
oil
pan,thenforces
it
through
a
replaceable
oil
filter

and
finto
the
engine
oíi
passages
.

On
4-cylinder
engines,
the
oil
pump
is
mounted
to
the
front

engine
cover
.
On
6-cylinder
engines,thechain-driven
oil

pump
is
bolted
to
the
bottom
of
the
cylinder
block
.

A
pressure
relief
valve
limits
the
maximum
system
pres-

sure
.
A
bypass
valve
prevents
the
oil
filter
from
bursting
and

insures
engine
lubrication
should
the
filter
become
plugged
.

See
119
Lubrication
System
for
additional
information
.

ENGINE-GENERAL
100-
5

Various
versions
of
DME
systems
are
usedon
thecars
cov-



MECHANICAL
TROUBLESHOOTING
ered
by
this
manual
.
See
Table
b
.
Each
system
is
highly
adaptive
to
compensate
for
things
suchasengine
wear
and



When
troubleshooting
an
engine
that
fails
to
start
or
runs
vacuum
leaks
.



poorly,
first
check
its
mechanical
condition-particularly
if
the

Warnings
and
Cautions

For
personal
safety,
as
well
asthe
protection
of
sensitive
electronic
components,
the
following
warnings
and
cautions
must
be
adhered
to
during
all
troubleshooting,
maintenance,
and
repairwork
.

WARNING
-

"
The
ignition
system
produces
high
voltages
that
can
be
fatal
.
Avoid
contact
with
exposed
termi-
nals
anduse
extreme
caution
when
working
on
a
car
with
the
ignition
switched
on
or
the
engine
running
.

"
Do
not
touch
or
disconnect
any
high
voltage
ca-
bles
from
the
coil,
distributor,
orspark
plugs
while
the
engine
is
running
or
being
cranked
by
the
starter

"
Connect
and
disconnect
the
engine
manage-
ment
system
wiring
and
test
equipment
leads
only
when
the
ignition
is
switched
off
.

"
Gasoline
is
highly
flammable
and
its
vapors
are
explosive
.
Do
not
smoke
or
work
on
a
car
near
heaters
or
other
fire
hazards
when
diagnosing
and
repairing
fuel
system
problems
.
Have
a
fire
extínguisher
available
in
case
of
an
emergency
.

"
Disconnecting
the
battery
may
erase
fault
code(s)
stored
in
control
module
memory
.
Using
special
BMW
diagnosnnc
equipment,
check
for
fault
codes
prior
to
disconnecting
the
battery
cables
.
If
the
Check
Engine
lightis
illuminated,
see
On-

Board
Diagnostics
(OBD)
forfault
code
infor-
mation
.
If
any
other
system
faults
havebeen
de-tected
(indicated
byan
illuminated
warning
light),
see
an
authorized
BMW
dealer
.

CAUTION-

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

"
Do
notconnect
any
test
equipment
that
delivers
a
12-volt
power
supply
to
terminal15
(+)
of
the
ignition
coil
.
The
current
flow
may
damage
the

ECM
.
In
general,
connect
test
equipment
only
as
specified
by
BMW,
this
manual,
or
the
equip-
ment
maker
.

"
Do
not
disconnect
the
battery
with
the
engine
running
.
Do
notrunthe
engine
with
any
of
the
sparkplug
wires
disconnected
.

MECHANICAL
TROUBLESHOOTING

100-
1
2
ENGINE-GENERAL

NOTE-

The
oxygen
sensor
signal
is
ignored
until
the
engine
reachesa
specified
minimum
temperature
.
Therefore,



The
primary
input
usedby
the
fuel
injection
system
to
deter-

when
troubleshooting
cold
engine
driveability
prob-



mine
how
much
fuel
should
be
delivered
is
the
signal
from
the

lems,
the
oxygensensor
canbe
ruled
out
asa
possible



mass
air
flow
sensor
in
the
intake
air
ductwork
.

cause
.

As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to

changing
conditions
deteriorates,
and
it
may
eventually
cease

to
produce
any
signal
at
all
.
To
check
the
operation
of
the
oxy-

gen
sensor,
see
130
Fuel
Injection
:

NOTE-

On
1996
and
latercars,
OBD
11
enhanced
emission
standards
require
the
engine
control
module
(ECM)
to
monitor
the
oxygen
content
in
the
exhaust
both
before
and
after
the
catalytic
converter
.
Thisallows
for
tighter
control
of
the
tail
pipe
emissions
and
also
allowsthe
ECM
to
diagnose
converter
problems
.
If
the
DME
de-
tects
that
catalytic
converter
or
oxygensensor
efficien-
cyhas
degraded
pasta
certain
pre-programmed
limit,
it
will
turn
on
the
Check
Engine
light,
and
store
a
diag-
nostic
trouble
code
(DTC)
in
the
ECM
.

DRIVEABILITY
TROUBLESHOOTING

Catalytic

B9506

Air
Flow
Measurement
and
Vacuum
Leaks

Because
proper
fuel
metering
depends
on
accurate
mea-

surement
of
the
incoming
air,
any
unmeasured
air
that
enters

the
engine
downstream
of
the
mass
air
flow
sensor
will
cause

a
lean
air-fuel
mixture
and
possibly
affectdriveability
.

NOTE-

Fig
.
10
.
Regulating
oxygen
sensor
measures
oxygen
content
of
ex-



gattery
Voltage
hausY
gas
as
indicator
of
.¡_fi
.1
ratio
and
"-k,
.

E-
effi-
ciency
.
Monitoríng
oxygen
sensor
(not
shown)
monitors

If
a
large
air
leak
is
causing
driveability
problems,
the
Check
Engine
light
will
usually
be
illuminated
and
a
fault
will
be
stored
in
the
fault
code
memory
.
See
On
Board
Diagnostics
(OBD)
.

There
are
many
places
for
unmeasured
air
to
enter
theen-

gine
.
First,
inspect
all
hoses,
fittings,
ducts,
seals,
and
gaskets

in
the
intake
air
tract
for
cracks
or
looseness
.
It
may
be
neces-

sary
to
remove
parts
that
cannot
be
fully
checked
in
their
in-

stalled
positions
.
Also
make
sure
all
of
the
intake
manifold
and

throttle
body
mounting
nuts
are
tight
.

In
addition
to
air
leaks,
air
restrictions
can
also
cause
drive-

ability
problems
.
Remove
the
air
filter
and
hold
it
up
to
a
strong

light
source
.
If
the
filter
does
not
pass
light,
it
is
restricted
and

should
be
replaced
.
Also,
remove
the
intake
air
ductwork
and

check
for
oily
deposits
at
the
throttle
plate
.
Buildup
in
this
area

can
cause
an
erratic
idle
.
Clean
away
any
deposits
using
a

cloth
wetted
withcarburetor
cleaner
and
reinstall
the
ductwork
.

CAUTION-

Do
not
spray
carburetor
cleaner
directly
in
the
throt-
tle
anea
.
Spraying
cleaner
may
force
it
into
the
throt-
tle
position
switch
or
sensor
and
cause
damage
.

catalytic
converter
operation
.



All
of
the
electrical
components
in
the
fuelinjection
and
igni-
tion
systems
require
a
minimum
voltage
to
operate
properly
.

When
troubleshooting
engine
driveability
problems,
one
of
Replacement
of
oxygensensors
at
the
specified
intenrals
en-



the
first
checks
should
be
to
make
sure
the
battery
is
fully
sures
that
the
engine
and
emission
control
system
wili
continue



charged
and
capable
of
delivering
allits
power
to
the
electricalto
operate
as
designed
.
As
the
oxygen
sensor
ages,
its
ability
to



system
.
react
quickly
to
changing
conditions
deteriorates,
and
it
may
eventually
cease
to
produceany
signal
at
all
.



To
make
a
quick
check
of
battery
charge,
measure
the
volt-
age
across
the
battery
terminals
with
all
cables
attached
and
As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to



the
ignition
off
.
A
fully
charged
battery
will
measure
12
.6
volts
changing
conditions
deteriorates,
and
it
may
eventually
cease



or
slightly
more,
compared
to
12
.15
volts
for
a
battery
with
a
to
produce
any
signal
at
all
.
To
check
theoperation
of
the
oxy-



25%
charge
.
gen
sensor,
see130
Fuel
Injection
.

Even
a
fully
charged
battery
cannot
deliver
power
unless
it

is
properly
connected
to
the
electrical
system
.
Check
the
bat-
tery
terminals
for
corrosion
and
loosecableconnections
.
If
the
battery
does
not
maintain
the
proper
voltage,
the
charging
system
may
be
atfault
.
See
121
Battery,
Starter,
Alternator
.

160-2



FUEL
TANK
AND
FUEL
PUMP

0011943
1
.
Filler
pipe



10
.
Fuel
compensating
siphon
pump
and
hose
assembly
2
.
Filler
pipe
grounding
tab



(models
built
from
1/95)
3
.
Vent
pipe



11
.
Fueltank
4
.
Threaded
collar



12
.
Tank
support
strap
5
.
Rubber
ring
seal



13
.
Bolt-tighten
to
23
Nm
(17
ft-Ib)
6
.
Fuel
pump



14
.
Fuel
expansion
tank
7
.
Left
side
fuel
leve¡
sender(models
built
from
1/95)



15
.
Fuel
tank
pressure
sensor
(OBD
II)
8
.
Right
side
fuel
leve¡
sender9
.
Left
side
fuel
leve¡
sender
with
fuel
compensating
siphon
pump
(models
built
up
to
1/95)

Fig
.
1
.



E36
fuel
tank
assembly
.

FUEL
TANK
AND
LINES



Fuel
tank,
draining

The
plastic
fuel
tank
is
mounted
beneath
the
center
of
the
car
(beneath
rear
seat)
.
Mounted
in
the
fuel
tank
are
the
fuel
pump
and
fuel
leve¡
sending
units
.
Connecting
lines
for
the
evaporative
emission
control
systemand
expansion
tank
are
also
attached
to
the
tank
.
When
performing
the
procedures
that
follow,
refer
toFig
.
1
.

Fuel
tank
capacity
for
E36
modeis

"All
ex
.
1996
M3
(3
.0
L)
.....
.
..
..
65
liters
(17
.0
gal)

"
1996
M3
(3.0L)
modeis
.
...
.
..
.
.62
liters
(16
.4
gal)

FUEL
TA
NKAND
LINES

The
fuel
tank
should
be
drained
into
an
approved
storage
unit
or
another
car's
fuel
tank
.

WARNING
-
"
Before
removing
the
tank,
be
sure
that
afl
hot
components
such
as
the
exhaust
system,
are
completely
cooled
down
.

"
Fuel
may
be
spilled
.
Do
not
smoke
or
worknear
heaters
or
other
Pire
hazards
.

1
.
Disconnect
negative
(-)
cable
from
battery
.

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
paga
vi¡¡
.

WARNING

Your
common
sense,
good
judge-
ment,
and
general
alertness
are
cru-
cial
to
safe
and
successful
service
work
.
Befcre
attempting
any
work
on
your
BMW,
read
the
warnings
and
cautions
on
page
vi¡
and
the
copyright
page
at
the
frontof
the
manual
.
Review
these
warnings
and
cautions
each
time
you
prepare
to
workon

your
BMW
.
Please
also
read
any
warnings
and
cautions
that
accom-
pany
the
procedures
in
the
manual
.

Door
glass
See
Door
windows
Door
windows
general
information
512-1
front
door
window
(2-door
models)
adjusting
512-7
removing/installing
512-5
front
door
window
(4-door
models)
initíalizing
512-1
removing/installing
512-2
rear
door
window
(4-door
models)
removing/installing
512-4
fixed
glass,
removing/installing
512-
4
rear
vent
window
or
vent
latch,
replacing
(2-door
models)
512-11
window
regulator
and
motor,
removing/installing
512-12
window
regulator
service
512-12Doorcheck
See
DoorsDoor
handle
See
Centrallocking
and
anti-theft
Door
panel
See
Doors
Doors
general
information
411-1
door
adjustment
411-2door
check,
replacing
411-2
door
panels
411-3
doors411-1
front
orrear
door,removing/installing
411-1
front
door
panel,
removing/installing

411-3
rear
door
panel,
removing/installing
411-4
rearsidepanel,
removing/installing
(two-door
model)
411-4
Drive
axle
See
Rear
suspension
Driveability
troubleshooting

See
Engine-general
Driveshaft
general
information
260-1
center
bearing
assembly,
replacing
260-6
driveshaft,
aligning
260-3
driveshaft,
installing
260-4

Driveshaft
(cont
.)
driveshaft,
removing260-4
driveshaftservice
260-3
flex-disc,
replacing
260-5
front
centering
guide,
replacing
260-7
guibo
See
flex-disc
troubleshooting260-1

ECM
(engine
control
module)
pin
assignment
See
Fuel
injection
Electrical
circuit
See
Electrical
system-general
Electrical
component
locations
general
information
610-1
auxíliary
relay
panel
610-2
component
location
table
610-9
component
locations
610-3
fuse
position
tables
610-19
fuse
positions
610-1
relay
positions
610-2
splice
panel,
left
610-2
splice
panel,
right
610-3
Electrical
system-general
general
information
600-1
continuity,
checking
600-5
electrical
test
equipment
600-2
safety
precautions
600-1

short
circuits
600-5
short
circuit,
testing
with
ohmmeter
600-6
short
circuit,
testing
with
voltmeter
600-6
troubleshooting
600-3
voltage,
measuring600-4
voltage
and
polarity
600-1
voltage
and
voltage
drops
600-4
voltage
drop,
testing
600-4
wiring
codes
and
abbreviations
600-2
wiring
diagrams
600-2
wiring,
fuses
and
relays
600-1
Electrical
wiring
diagrams
general
information
ELE-1
wiring
diagrams
ELE-2
ABS
ELE-117

ABS/AST
ELE-120
airbag
(supplemental
restraint
system)
ELE-140
air
conditioning
and
heating
ELE-
129
anti-theft
(Alpine)
system
ELE-144
anti-theft
(EWS
II)
ELE-150
body
computer
module
ELE-176
charging
system
ELE-67
convertible
top
ELE-253
cruise
control
ELE-112
data
link
connector
ELE-86
engine
cooling
ELE-94
engine
management
ELE-70
exterior
lights
ELE-194
ground
distribution
ELE-35

headlights/foglights
ELE-180

INDEX
3

Electrical
wiring
diagrams
(cont
.)

heated
seats
ELE-245

horns
ELE-153
instrument
panel
ELE-165
interior
lights/illumination
ELE-211
lumbar
control
ELE-247
on-board
computer
ELE-173
park
ventilation
ELE-139
power
distribution
ELE-2
power
door
locks
ELE-226
power
mirrors
ELE-241
power
seats
ELE-243

power
sunroof
ELE-248

power
windows
ELE-231
radio/cassette/CD/speakers
ELE-
255
rear
window
defogger
ELE-160
shift
interlock
ELE-110
starting
ELE-63
transmission
electronics
ELE-96
warning
systems`
.
chimes
ELE-178
wiper/washer
ELE-154
Emergencies
See
Fundamentals
for
the
do-it-
yourself
owner
Engine-general
general
information
100-1
air
flow
measurement
and
vacuum
leaks
100-12
basic
engine
settings
100-11
basic
requirements
100-11
battery
voltage
100-12connecting
rods
and
pistons
100-1
cooling
system
100-5
cylinder
block
and
crankshaft100-1
cylinder
compression,
checking
100-6
cylinder
head
and
valvetrain
100-2
DISA
(dual
resonance
intake
system)
100-3,130-3
driveability
troubleshooting
100-8
engine
management
system
100-3
fuel
delivery
100-5
fuel
supply
100-14ground
connections
100-13
ignition
100-5
lubrication
system100-5
mechanical
troubleshooting
100-5
on-board
diagnostics
(OBD)
100-8
oxygen
sensors
100-11
preventive
maintenance
100-11
VANOS
(variable
valve
timing)
100-2warningsand
cautions
100-5
wiring
andharness
connections100-
13Engine
control
module
(ECM)
See
Fuel
injection
Engine
removal
and
installation
general
information
110-1
engine,
removing/installing(4-cylinder
engines)
110-1
engine,
removing/installing
(6-cylinder
engines)
110-4
Engine
coolant
temperature
(ECT)
sensor
See
Fuel
injection
Engine
hood
See
Fenders,
enginehood