1994 BMW M3 reset

IGNITION
SYSTEM
DIAGNOSTICS



IGNITION
SYSTEM
SERVICE

Poor
driveability
may
have
a
variety
of
causes
.
The
fault



On
4-cylinder
engines,
an
ignition
coil
pack
is
mounted
to

may
lie
with
the
ignition
system,
the
fuel
system,
parts
of
the



the
passenger
side
strut
tower
in
the
engine
compartment
.

emission
control
system,
or
a
combination
of
the
three
.
Be-



The
coil
pack
integrates
4
individual
coils
.

cause
of
these
interrelated
functions
and
their
effects
oneach

other,
it
is
often
difficult
to
know
where
to
begin
looking
for



On
6-cylinder
engines,
an
ignition
coil
is
located
directly

problems
.



above
each
spark
plug
.

For
this
reason,
effective
troubleshooting
should
alwaysbe-

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

system
.
The
OBD
system
detects
certain
emissions-related

engine
management
malfunctions
.
When
faults
are
detected,

the
OBD
system
stores
a
Diagnostic
Trouble
Code
(DTC)
in

the
system
ECM
.
In
addition,
the
Check
Enginewarning
light

will
come
on
if
an
emissions-related
fault
is
detected
.

Two
generations
of
OBD
areusedon
the
cars
coveredby

this
manual
.
See
100
Engine-General
for
OBD
information
.

On-Board
Diagnostics

"
1992-1995
models
............
...
.
..
...



OBD
I

"
1996
and
later
models
.........
.......
..
OBD
II

NOTE-

"
On
carswith
OBD
ti,
specialized
OBD
11
scan
tool

equipment
mustbeused
to
access
DTCs,
either
using

the
BMW
special
tool
or
a
`generic"
OBD
11
scan
tool
.

"
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
dísconnecting
the
battery
will
not
erase
the
fault

memory
.

Basic
Troubleshooting
Principies

An
engine
that
starts
and
runs
indicates
the
ignition
system

is
fundamentally
working-delivering
voltage
toat
least
some

of
the
sparkplugs
.
A
hard-starting
or
poor-running
engine,

however,
may
indicate
ignition
coil
problems,
cracked
or
dete-

riorated
spark
plug
wires
(4-cylinder
engines
only),
and
worn

or
fouled
spark
plugs
.

WARNING
-

Inefficient
combustion
(richair/fuel
mixture)
can

cause
the
catalytic
converter
to
overheat
and
plug
.

An
overheated
catalytic
converter
can
also
bea
tire

hazard
.

Checking
for
Spark

IGNITION
SYSTEM



120-
3

WARNING
-

If
a
spark
test
is
done
incorrectly,
damage
to
theen-
gine
control
module
(ECM)
or
the
ignitioncoil(s)
may
result
.

Checking
for
spark
is
difficult
onengines
with
distributorless

ignition
systems
.

Try
Rmovng
the
plugs
and
inspecting
for
differences
be-

tween
them
.
A
poor-firing
plug
may
be
wet
with
fuel
and/or

black
and
sooty,
butnot
always
.
If
a
coil
is
not
operating,
the

engine
management
system
will
electrically
disable
the
fuel
injectorto
that
cylinder
.
The
key
is
to
look
for
differences
be-

tween
cylinders
.

Ignition
coil,
testing
and
replacing

(4-cylinder
engine)

1.
Disconnect
mainharness
connector
from
coils
:

"
On
M42
engine,
remove
plastic
covering
from
coils
and

disconnect
individual
harness
connectors
.

"
On
M44
engine,
disconnect
main
harness
connectorat

end
of
coil
pack
.
See
Fig
.
3
.

Fig
.
3
.



Ignition
coil
pack
for
M44
engine
(arrow)
.
Coil
harness
con-

nector
shown
at1
.

IGNITION
SYSTEM
SERVICE

The
fuel
injection
systems
used
on
the
1996
and
later
cars
covered
bythis
manual
are
OBD
II
compliant
.
This
system
is
in-
corporated
into
both
the
Bosch
M5
.2
(M44
engine)
and
the
Si-
emens
MS
41
.1
(M52/S52US
engine)
engine
management
systems
.
OBD
II
systems
use
sophisticateddiagnostic
soft-
ware
capable
of
recognizing
and
electronically
storing
hun-
dreds
of
DTCs
in
the
system
ECM
.
DTCs
can
only
be
accessed
using
special
scan
tooltest
equipment
.
The
BMW
dealer
is
equipped
with
the
specialized
OBD
II
scan
toolto
quickly
and
efficiently
locate
engine
management
problems
.
Alternately,
a
"generic"
scan
tool
can
be
used
to
access
OBD
II
fault
informa-
tion
.

NOTE-

"
At
the
time
this
manual
went
to
press,
generic
scan
tools
were
notwidely
available
for
BMW
vehicles
.
The
generic
sean
tool
is
a
specialized
toolthat
plugs
into
a
standardized
OBD
11
connector
on
1996
and
later
pas-senger
vehícles
built
for
sale
in
the
US
.

"
The
OBD
11
fault
memory
(including
an
illuminated
Check
Engine
light)
can
only
be
reset
using
the
spe-
cial
scan
tool
.
Removing
the
connector
trom
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
.

6

1
.
Secondary
air
pump
2
.
Electric
solenoid
valve
3
.
One-way
check
valve
4
.
Intake
manifold
5
.
Exhaust
manifolds
6
.
Secondary
air
check-valve

®
G~



i

o
o



0
0
G
0000
o



,-
00

~

1111111
in

,,
0
1--

a

Fig
.
5
.



Components
of
6-cylinder
secondary
air
injection
system
.
4-
cylinder
system
is
similar
.

Secondary
AirInjection

FUEL
INJECTION



130-
5

All
OBD
II
6-cylinder
engines
are
equípped
with
asecond-
ary
air
injection
system
.
In
addition,
beginning
in
January
1997,
the
M44
engine
was
classified
as
a
TLEV
(Transitional
Low
Emission
Vehicle)
engine
and
is
also
equipped
with
sec-
ondary
air
injection
.

Typical
components
of
the
secondary
air
injection
system

are
depicted
in
Fig
.
5
.

Secondary
air
injection
usesan
electric
pump
to
pump
fresh
air
finto
the
exhaust
systemupstream
of
the
catalytic
converter
during
engine
warm-up
.
By
providing
extra
oxygen
to
the
un-
burned
fuel
in
the
exhaust,
hydrocarbons
oxidize
and
carbon

monoxide
combines
with
oxygen
to
form
carbon
dioxide
andwa-
ter
.
The
air
injection
pump
stops
within
a
specified
timed
intenral
.

4

0013120

GENERAL

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

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

Fig
.
13
.
Lifting
arm
retaining
clips
(arrows)
at
window
slides
.

12
.
Tip
window
so
rear
ofglass
is
up
out
of
door
.
While
sup-
porting
window,
remove
window
front
limit
stopbracket
.
See
Fig
.
14
.

0013067

Fig
.
14
.
With
window
glass
shown
partially
tipped
out
of
door,
remove
bolt
A
and
loosen
bolt
B
in
order
to
remove
front
window
limit
stop
bracket
.

13
.
Take
glass
fully
out
of
door
.

14
.
Installation
is
reverse
of
removal,notingthe
following
:

"
Guide
front
of
window
into
front
guide
rail
and
rest
it

therewhile
installing
front
window
limit
stop
bracket
.
"
When
installing
window
rear
guide
bracket,
tighten

countersunk
screws
in
glass
first
(throughoutside
of

door),
then
install
guide
rail
bracket
.

"
Insert
rubber
sea¡
at
top
of
door
correctly
See
Fig
.
15
.

"
Use
new
mounting
bolts
when
reinstalling
the
side-im-

pactairbag
to
the
door
(where
applicable)
.
Reset
SRS
warning
light
and
clear
SRS
fault
memory
using
spe-
cial
test
equipment
.
See
721
Airbag
System
(SRS)
.

"
Adjust
window
as
described
later
.

"
Re-inítialize
window
regulator
motors
as
described

earlier
.

DOOR
WINDOWS



512-
7

Fig
.
15
.
Correct
installation
of
door
toprubber
seal
.

Tightening
Torques

"
Rear
guide
bracket
to
window
.......
6
Nm
(53
in-lb)

"
Rear
guide
bracket

to
roller
guide
..
.
...
...............
9
Nm
(7
ft-Ib)

Front
door
window,
adjusting

(2-door
modeis)

The
"closewith
door
shut"
feature
of
2-door
cars,
as
well
as

the
frameless
window,
makeswindow
adjustment
critical
:

WARNING
-

"
Some
1997
and
afl
1998
2-door
cars
are
fitted
with
side-impact
airbags
in
the
front
doors
.
When
ser-
vicingthe
door
windows
on
cars
with
front
side-im-
pact
airbags,
always
disconnect
the
negative
(-)
battery
cable
.
See
721Airbag
System
(SRS)
for
cautions
and
procedures
relating
to
the
airbag
sys-
tem
.

"
Adjusting
the
front
window
requires
that
the
bat-
tery
cable
be
reconnected
with
the
side-impact
airbag
disconnected
.
This
will
set
a
fault
code
in
the
SRS
control
module,
turn
on
the
SRS
warning
light,
and
disable
the
SRS
system
until
the
fault
memory
is
cleared
using
special
SRS
test
equip-
ment
.

"
There
is
risk
of
window
glass
breakage
if
correct
adjustment
proceduresare
not
used
.
If
in
doubt,
this
procedureshouldbe
left
to
a
trained
BMW
technician
.

WINDOW
SERVICE,
2-DOOR
MODELS

512-
1
0



DOOR
WINDOWS

0013078

Fig
.
22
.
Move
window
fore/aftatrear
guide
rail
top
mounting
bolts
(ar-

rows)
.

Insertion
Depth

"
A
(See
Fig
.
17
.)
.
..........
.1-1
.5
mm
(0
.04-0
.6
in
.)

6
.
To
set
Insertion
depth
C
(Refer
to
Fig
.
17
.)
:

"
Lower
window
slightly
.
Loosen
stop
at
window
regula-

tor
motor
.
See
Fig
.
23
.

Fig
.
23
.
Window
regulator
stop
(arrow)
.

WINDOW
SERVICE,
2-DOOR
MODELS

0013075

"
Raise
window
.
Loosen
rear
boltat
regulator
support

arm
(5mm
Allen
wrench)
.
See
Fig
.
24
.
Align
window

parallelto
roof
line
by
moving
support
arm
up
or
clown
.

Tighten
arm
bolt
.

"
Lower
window
and
remove
rubber
plugs
at
bottom
of

door
.
If
necessary,temporarily
reconnect
battery
ca-

ble
.

"
Adjust
front
and
rear
limit
stops
so
that
window
retracts

into
window
seal
as
specified
.
See
Fig
.
25
.

"
Raise
window
to
check
adjustment
.

"
Push
regulator
stop
fully
forward
and
tighten
bolt
.

"
Closedoor
and
check
window
operation
.

0013077

Fig
.
24
.
Use
5mm
Afen
socket
to
loosen
mounting
boltat
support
bracket(arrow)
and
slide
bracket
up
or
clown
to
adjust
win-
dow
position
at
roof
line
.
(Allen
bolt
head
faces
outside
of
door
.)

CAUTION
-

"
Recheck
preload
gap
B
(step
4)
.
Excessive
pre-
load
could
cause
window
to
shatter
.

"
The
fully
closed
window
must
not
contact
the
rain
gutter
when
opening
the
door
(in
the
event
the
"close
with
door
shut"
feature
is
faulty
or
the
bat-tery
is
dead)
.

7
.
Usenew
mounting
bolts
when
reinstalling
the
side-im-
pact
airbag
to
the
door
(where
applicable)
.
Reset
SRS
warning
light
and
clear
SRS
fault
memory
using
special

test
equipment
.
See
721
Airbag
System
(SRS)
.

8
.
Replace
door
panel,
rubber
door
plugs
and
outside
doormolding
.

9
.
Re-initialize
window
regulator
motors
as
described
ear-
lier
.

515-4



CENTRAL
LOCKING
AND
ANTI-THEFT

11
.
Installation
is
reverse
of
removal
.
Keep
in
mind
the
fol-



4
.
Remove
screws
mounting
bottom
of
window
rear
track

lowing
:



to
door
.
See
Fig
.
9
.

"
Make
sure
rubber
seal
for
handle
is
correctly
posi-

tionedbefore
tightening
mounting
fasteners
.

"
Install
exteriortrim
piece
and
then
use
a
hooked
tool
to

pull
locking
plate
into
locked
position
.
Make
sure
door

handle
trim
contacts
body
evenly
before
locking
trim

in
place
.

"
Use
new
mounting
bolts
when
reinstalling
the
side-im-

pactairbag
to
the
door(where
applicable)
.
Reset
SRS

warning
light
and
clear
SRS
fault
memory
using
spe-

cial
test
equipment
.
See
721
Airbag
System
(SRS)
.

"
Reconnect
al¡
harness
connectors
(including
power

window
motor)before
installing
door
panel
.

"
Secure
wire
harnesses
withwire
ties
.

"
Adjust
and
reinitialize
windows
.
See
512
Door
Win-

dows
.

Tightening
Torque

"
Collar
nut
to
doorhandle
..........
10
Nm
(89
in-lb)

1.
Remove
rear
door
panel
and
vapor
barrier
as
described

in
411
Doors
.

2
.
Remove
window
from
rear
dooras
described
in
512

Door
Windows
.

3
.
Disconnect
andremove
inside
door
handle
.
See
Fig
.
8
.

0013073

Fig
.
8
.



Inside
door
handle
retaining
screw
(A)
Unhook
linkage
from
handle
at
B
.

DOOR
HANDLES
AND
LOCKS

Fig
.
9
.



Rear
window
track
lower
fasteners
(arrows)
.

Reardoor
lock,
removing
and
installing



5
.
Remove
window
rear
track
top
screw
and
move
track

aside
.
See
Fig
.
10
.

Fig
.
10
.
Rear
window
track
top
screw
(arrow)
.

6
.
Remove
screw
from
lock
button
linkage
rod
retainer
.
Lift

rod
out
of
retaining
clip
.
See
Fig
.
11
.

7
.
Disconnect
door
lock
harnessconnector
.

8
.
Remove
door
lock
screws
.
See
Fig
.
12
.

0013085

9
.
Move
lock
upslightly
to
disengage
from
exterior
handle

linkage
.
Remove
lock
from
inside
door
.

The
left
latch
in
the
fully
automatic
version
hastwo
mi-
croswitches
(S7
and
S8)which
signal
open,
closed
and
latched
states
.
See
Fig
.
8
.

The
length
of
the
dead
center
point
rod
is
critica¡
lo
correct
opening
and
latching
of
the
convertible
top
.
See
Fig
.
9
.

Dead
Center
Point
Rod

"
Dimension
A
........
205
.5
f
1
mm
(8
.09
t0
.04
in)

Visor
Latch
Motor

The
fully
automatic
convertible
top
is
latched
and
unlatched
by
one
electric
motor
installed
in
the
front
roof
bow
.
To
re-
place,
remove
front
cover
trim
from
the
roof
.
Remove
electri-
cal
harness
connectors
from
motor,
andremove
mounting
screws
.
Slide
the
motor
off
the
output
shafts
to
the
left
and
right
latches
.

During
reinstallation,
theoutput
shafts
must
be
tumed
until
the
S8
microswitch
in
the
left
latch
is
tripped
.

Convertible
top
and
frame,
replacing

1
.
Open
convertible
top
partially
.
Open
convertible
top
lid
.



Fig
.
9
.



Preset
lengthof
dead
centerpoint
rod
.
Open
back
windows
.

2
.
Fully
automatic
power
convertible
top
:
Remove
front
cover
trim
from
top
.
Disconnect
electrical
harness
con-

nectors
from
frontlatch
motor
.
Disconnect
connectors

from
S7
and
S8
microswitches
at
left
latch
.

Motors
M1
Convertible
top
M2
Convertible
top
lid
M3Front
latch
(fully
automatic
top)

Microswitches
S1
&S2
In
convertible
top
motor
S3
In
convertible
top
storage
compartment
S4
In
top
linkage
(semi-automatic
only)
S5
In
luggage
compartment
latch
S6
In
right
convertible
top
lid
latch
S7&S8
In
left
conv
.
top
latch
(fully
automatic)

Fig
.
8
.



Locationof
automatic
and
semi-automatic
convertible
latch
mechanisms,
motors
and
microswitches
.

CONVERTIBLE
TOP



541-5

POWER
CONVERTIBLE
TOP