diagnostic BMW 318i 1997 E36 Owner's Guide

Table
I
.
ECM
Pin
Assignment-Siemens
DME
MS
41
.1
(continued)

Pin



I
Signal



I
Component/function



1
Signal

FUEL
INJECTION



130-
37

47
-

48



input



Crankshaft
position
sensor
(Hall
effect)



Crankshaft
position
sensor
control

49



input



Power
supply
(terminal
15)



Batteryvoltage
with
key
onor
engine
running
50



output



Solenoid
valve
(running
losses)



Running
losses

51



output



Carbon
canister
valve



Carbon
canister
valve
control

52vacant
-

53



output



Idle
speed
control
valve



Pulsed
ground-close
signal
(seealsopin29)
54



input



Power
supply



Battery
voltagefrom
main
relay
(terminal
87)

55
vacant
-

56
-

57



input



Knock
sensor
(cyl
.
1-3)



Knock
sensor
input
Signal

58



output



Knock
sensor
(cyl
.
1-3)



Knock
sensor
control

59



input



Knock
sensor
(cyl
.
4-6)



Knock
sensor
input
Signal

60



input/output



Diagnostic
connector
(TxD)



Diagnostic
TxD
(transmit)
signal
to
pin
18
in
Data
link
connector
61



output



Oxygen
sensor
heater
(monitoring
sensor)



Oxygen
sensor
heater
ground

62



output



Secondary
air
injection



Secondary
air
injection
control
valve

63



output



Knock
sensor
(cyl
.
4-6)



Knock
sensor
control

64



input



Camshaft
position/rpm
sensor



Camshaft
position/rpm
sensor
control

65



input



Camshaft
position/rpm
sensor



Camshaft
position/rpm
sensor
control

66
-

67



output



Oxygen
sensor



Oxygen
sensor
reference
voltage

68



output



Evaporative
purge
valve
control



Pulsed
ground
with
engine
at
normal
temperature
and
varyingengine
load

69



output



Fuel
pump
relay
control



Fuel
pump
relay
switches
with
engine
runningorcranking
(crankshaft
position
signal
must
be
present
for
relay
switchover)

70
vacant
-



-

71



output



Oxygen
sensor
heater
(regulating
sensor)



Oxygen
sensor
heater
ground

72



output



Oxygen
sensor
(monitoring
sensor)



Oxygen
sensor
referencevoltage

73



input



Main
relay
control



Main
relay
activation
(terminal
85)

74



output



A/C
compressor
control



A/C
compressor
relay
control

75



input



Oxygen
sensor



Oxygen
sensor
signal

76



not
used



-



-

77



input



Oxygen
sensor
(regulating
sensor)



Oxygen
sensor
signal

78



input



Oxygen
sensor
(monitoring
sensor)



Oxygen
sensor
signal

79



output



Oxygen
sensor
(regulating
sensor)



Oxygen
sensor
referencevoltage

80



Traction
control



AST
module

81



Traction
control



AST
module
82



Traction
control



AST
module
83



output



Crankshaft
position
sensor
(Hall
effect)



Crankshaft
position
sensor
control

84
vacant
-



-

85



output



Automatic
transmission



Automatic
transmission
control
module

86



input



Automatic
transmission



Automatic
transmissíon
control
module

87



input



Power
supply



Battery
voltage
from
main
relay
(terminal
87)

88



input/output



Diagnostic
connector
(TxD)



Diagnostic
TxD
(transmit)
signal
to
pin
17
in
Data
link
connector

ECM
PIN
ASSIGNMENTS

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
.

AUTOMATIC
TRANSMISSION



240-1

240
Automatic
Transmission

GENERAL
.....
.
.
.
.
.
.
.
.
.
.
.
.
.
.........
.
240-1



TRANSMISSION
REMOVAL
AND

INSTALLATION
..................
.
.
.
.
.240-4
TRANSMISSION
SERVICE
.
.
.
.
.
.......
.
240-1



Transmission,
removing
and
installing
....
.
.
.240-4

ATF
leve¡,
checking
..
.
.
.
.
.
.
.
.
.
..........
240-1

ATF,
draining
and
filling
.
.
.
.
.
.
.
..........
240-2



TABLE

a
.
Automatic
Transmission
Gear
Ratios
.......
..
.
.
240-1

GENERAL



TRANSMISSION
SERVICE



lo

Automatic
transmissions
are
identified
by
code
letters



ATF
leve¡,
checking

foundon
a
data
plate
located
on
the
sideof
thetransmission

case,
behind
the
manual
valve
lever
.
See
200Transmis-



The
automatic
transmissions
installed
in
the
E36
models
sion-General
for
application
information
.
Forgear
ratio
spec-



are
normally
filled
with
Dexron
III
automatic
transmission
fluid

ifications,
see
Table
a
.



(ATF),
although
alternative
fluids
have
been
installed
from
the

factory,
depending
on
transmission
type
and
model
year
.

CAUTION-



Some
transmíssions
are
filled
with
a
special
BMW
"lifetime"

ATF
does
not
circulate
unless
the
engine
is
run-



automatic
transmission
fluid,
which
does
not
require
periodic

ning
.
When
towing
an
automafic
transmission
ve-



fluid
changes
.

hicle,
usea
flat-bed
truck
or
ralse
the
rear
wheels
off
the
ground
.



CAUTION-

Mixing
different
types
of
transmission
fluids
will

The
electronic
transmission
control
module
(TCM)
monitors



lead
to
transmission
failure
.

transmissionoperation
for
faults
and
alerts
the
driver
by
illumi-

nating
the
transmission
fault
indicator
on
the
instrument
pan-

el
.
On-board
diagnostic
codes
stored
in
the
TCM
mustbe



NOTE-

downloaded
and
interpreted
by
trained
technicians
using
spe-



The
transmission
lubricant
instafed
can
be
foundona

cial
BMW
diagnostic
equipment
.



type
plate
on
the
side
of
the
transmission
.
In
addition,
a
sticker
may
be
located
on
the
fluid
sump
indicatingthe
typeof
transmission
lubricant
used
.
Ifin
doubt,
con

NOTE-



sult
an
authorized
BMW
dealer
for
altemate
fluid
use

Internal
repairs
to
the
automatic
transmission
require



and
current
information
regardingtransmission
operat-
special
service
equipment
and
knowledge
.
If
it
is
deter-



ing
fluids
.

mined
thatinterna¡
service
is
required,
consult
en
au-

thorízedBMWdealerabouta
factoryreconditioned
unit



The
transmission
is
not
equipped
with
a
dipstick
.
Checking
or
a
transmission
rebuild
.



the
ATF
leve¡
requires
measuring
and
maintaining
a
specified

ATF
temperature
during
the
checking
procedure
.
The
check-

ing
temperature
is
not
fully
warm
orcold
(the
ATF
sump

should
be
approximately
warm
to
the
touch)
.

Table
a
.
Automatic
Transmission
Gear
Ratios

Transmission



MS
310R
(THM-R1)



MS
310R
(THM-Rl)



MS
310Z(5HP
18)



I



MS
270R
(THM-R1)
(1992-1993)(1993-on)

Gear
ratios
:
1st



2
.40



2
.86



3
.67



2
.86

2nd



1
.47



1
.62



2
.00



1
.62
3rd



1
.00



1
.00



1.41



1
.00
4th



0
.72



0
.72



1
.00



0
.72
5th



-



-



0
.74



-
Reverse



2
.00



2
.00



4
.10



2
.00

TRANSMISSIONSERVICE

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
.

GENERAL
.
....
.
.
.
.
.
.......
.
.
.
.
.
...
.
.
.
400-1



INTERIOR
EQUIPMENT
......
.
.
.
.......
400-4
Seats
and
Seatbelts
.
.
.
.
.
.
.....
.
.
.
.
.
..
.
..
400-4
BODY
ASSEMBLY
.
.
.
.
.
.....
.
.
.
.
.
.
.
.
.
.
.400-2



Instruments
and
Controls
.
..
....
.
.
.
.
.
.
.
...
400-4

Exterior
and
Aerodynamics
....
.
.
.
.
.
.
.
.
.
.
.
400-2



Central
Body
Electronics
.......
.
.
.
...
.
...
400-5

Coupe
Models
..
.
.
.
.
.
.......
.
.
.
.
.
.
.
.
.
..
400-3



Electronic
Immobilization
System
.
.
.
...
.
...
400-5

Convertible
Models
.
.
.
.
.
.
.
.....
.
.
.
.
.
.
.
..
400-3



Heating
and
Air
Conditioning
.
...
.
.
.
.
.
.
.
...
400-6

GENERAL

This
section
covers
system
descriptions
and
general
ser-

vice
information
for
the
repair
groupsfound
in
4
Body
and
5

Body
Equipment
.

When
working
or
servicing
cars
equipped
with
SRS
air-

bag(s),
the
following
precautions
must
be
observed
to
prevent

injury
.

F19
.1
.
The
BMW
E36
coupe
.

400
Body-General

BODY-GENERAL
400-1

WARNING
-

"
Airbags
are
inflated
by
an
explosivedevice
.
Han-dled
improperly
or
without
adequate
safeguards,
airbag
units
can
be
very
dangerous
.
Special
pre-cautions
must
be
observed
prior
to
any
work
ator
near
the
driver's
side
airbag,
the
passenger's
side
airbag
(where
applicable),
or
the
side-impact
aírbags
(where
applicable)
.
See
721
Airbag
Sys-
tem
(SRS)
.

"
Always
disconnect
the
battery
and
cover
the
neg-
ative
(-)
battery
terminalwith
an
insulator
before
starting
diagnostic,
troubleshooting
or
service
work
oncars
fitted
with
SRS,
and
before
doíng
any
welding
on
the
car
.

0013098

GENERAL

Ambient
temperaturelclock

MÍM
Aa
.Mi}rm
-Mil"
IMua~naa~u~itacar
"
za
.~

Central
Body
Electronics

0013028

Fig
.
4
.



Different
versionsof
Multi-information
Display(MID)
installed
in
E36
cars
.

The
E36
cars
are
equipped
with
a
sophisticated
centralized

body
electric/electronics
plan
.
The
system
is
self-diagnostic

and
incorporates
many
functions
into
a
single
control
module
.

The
consolidation
of
several
systems
into
a
single
control

module
minimizes
power
requirements
and
the
incorporation

of
the
diagnostic
link
results
in
more
efficient
and
accurate

troubleshooting
.

Self-diagnostic
codes
are
accessible
electronically
through

the
data-link
connector
in
the
engine
compartment
.
See610

Electrical
Component
Locations
.

BODY-GENERAL
400-
5

Two
versions
of
central
body
electronics
are
used
depend-

ing
on
model
year
.

1992
and
1993
models
are
equipped
with
a
central
locking

module
(ZVM)
which
incorporates
control
of
the
following
sys-

tems
:

"Interiorlighting
"
Central
locking
with
double
lock
feature

"
Output
relays
for
powerwindows
and
sunroof

"
Electronic
power
protection

E36
cars
since
the
1994
model
year
are
equipped
with
ZKE

IV
.
This
is
an
electronic
comfort
and
convenience
system
that

includes
the
following
additional
features
:

"
One
touch
up/down
power
window
operation

"
Power
window
and
sunroof
closure
from
driver
or
pas-

sengerdoor
lock

"
Vehicle
locking
or
unlocking
from
the
trunk
lock
.

Other
features
of
the
system
are
discussed
in
515
Central

Locking
and
Anti-Theft
.

Electronic
Immobilization
System

Beginning
in
model
year
1994,
all
E36
vehicles
incorporate

adriveaway
protection
system
regardless
of
whether
the
vehi-

cle
is
equipped
with
a
BMW
Alarm
System
or
an
On-Board

computer
.
Two
types
of
factory
systems
were
installed,
de-
pending
on
vehicle
production
date
.

On
the
early
system
(model
year
1994
up
to
January
1995),

the
ignition
and
fuel
injection
functions
are
disabled
whenever

the
vehicle
is
locked
in
the
double
lock
mode
.
This
is
referred

lo
as
EWS
or
EWS
I
.

Beginning
in
January
1995,
the
driveaway
protection
sys-

tem
was
upgraded
to
a
more
sophisticated
system,
called

EWS
II
.
This
system
uses
a
wireless
communication
link
be-

tween
a
transponder
chip
in
the
ignition
keyand
the
ring
an-

tenna
surrounding
the
ignition
switch
.
The
EWS
II
control

module
blocksthe
starting
of
the
vehicle
unlessthe
correct

coded
ignition
key
is
used
.

For
further
information
about
drive
away
protection
sys-

tems,
see
515
Central
Locking
and
Anti-Theft
.

INTERIOR
EQUIPMENT

515
Central
Locking
and
Anti-Theft

GENERAL
.....
.
.
.
.
.
.
.
..:
.
.
.
......
.
.
.
.
515-1



Luggage
compartment
locking
actuator,
removing
and
installing
.
.
.
.
.
...........
.
515-6

DOOR
HANDLES
AND
LOCKS
.........
515-1



LOCKING
SYSTEM
AND
Front
door
lock,
removing
and
installing
....
.515-1



ELECTRONIC
IMMOBILIZATION
......
.515-7
Front
door
handle,
removing
and
installing
...
515-3

Rear
door
lock,
removing
and
installing
.....
515-4



Central
Locking
System(ZVM)
.
.
.
.
.......
.
515-7

Rear
door
handle,
removing
and
installing
...
515-5



Central
Body
Electronics
(ZKE
IV)
.
.
.......
.515-8

Electronic
Immobilization
System
(EWS)
.
.
.
.
.515-8
Door
striker,
rep
lacing
.
.
.
.
.
.
.
.
.
..........
515-6



EWS
II
control
module,
re
lacin



515-10

LOCKING
ACTUATORS
.
.
.
.
.
.
..........
515-6



Ring
antenna,
replacing
.
.
.
.
.
.
.
.
.
.
...
.
.
.
.
515-10

Door
Locking
Actuator
.
.
.
.
.
.
.
.
..........
515-6



EWS
II
transmitter/receiver
module,

replacing
...........
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
515-11

GENERAL

This
section
covers
repair
information
for
the
central
locking

and
the
anti-theft
systems
.
Keep
in
mind
that
E36
cars
are



CA
UTION-

equipped
with
sophisticated
and
self-diagnostic
electrical
sys-



Prior
to
disconnecting
the
battery,
read
the
battery

tems
.
When
experiencing
malfunctions
relatinglo
the
central



disconnection
cautions
given
at
the
front
of
this

locking
or
the
anti-theft
system,
it
is
recommended
that
the



manual
onpage
vi¡¡
.

systembe
diagnosed
using
the
BMW
service
tester
(DIS)
.

This
advanced
diagnostic
tool
can
usually
pinpoint
electrical



NOTE-
faults
quickly
and
safely
.
Consult
an
authorized
BMW
dealer
.
In
some
models
covered
inthis
manual,
it
is
not
essen-
tial
to
remove
the
side-impact
airbag
to
access
intemal

NOTE-



door
components
.
However,
the
procedure
is
recom-

Additional
general
electrical
information
can
be
found



mended
for
safely
reasons
.

i
n
610
Electrical
Component
Locations
and
Electri-
cal
Wiring
Diagrams
.



4
.
Disconnect
harnessconnector
from
window
motor
to

DOOR
HANDLES
AND
LOCKS

Front
door
lock,
removing
and
installing

1
.
Remove
front
door
panel
and
vapor
barrier
asde-

scribed
in
411
Doors
.

WARNING
-

Some
1997
and
all
1998
cars
are
fitted
with
side-im-

pact
airbags
in
the
front
doors
.
When
servicing
the
door
locks
on
cars
with
front
side-impact
airbags,
al-
ways
disconnect
the
negative
(-)
battery
terminal
.
See721
Airbag
System
(SRS)
forcautions
andpro-
cedures
relating
to
the
airbag
system
.

2
.
Raise
door
window
completely

CENTRAL
LOCKING
AND
ANTI-THEFT



515-1

3
.
On
cars
with
side-impact
airbags,
disconnect
negative
(-)
cable
from
battery,
then
remove
airbag
module
.

prevent
accidental
operation
.

5
.
On
4-door
cars
:
Peel
back
rubber
window
guide
from

reas
guide
rail
:
Remove
guide
rail
mounting
boltat
bot-

tom
.
Unclip
any
wiring
from
guide
rail
and
pull
guide
rail

downward
and
remove
from
door
.
See
Fig
.
1
.

NOTE
-

The
top
of
the
guide
rail
is
"hooked"
to
the
doorsheet
metal
.

6
.
Remove
inside
door
handle
retaining
screw
.
Discon-

nect
inside
handle
from
linkage
and
remove
.
See
Fig
.

2
.

7
.
Cut
wire
ties
and
remove
door
lock
electrical
harness
con-

nector
.
Remove
door
lock
mounting
screws
.
See
Fig
.
3
.

8
.
Working
inside
door,
disconnect
outside
door
handle

and
lockcylinder
linkage
from
door
lock
.
Remove
lock

from
inside
door
.
See
Fig
.
4
.

DOOR
HANDLES
AND
LOCKS

541-
4



CONVERTIBLE
TOP

Folding
roof

Frontlatches

Convertible
topframe

i

Lower
mounting
pata
Horizontal
positioning
~~-
bolt
Manual
front
8
e
latch



1
handle

~



O

Visor
latchplata

Fig
.
6
.



Mechanical
components
of
E36
convertible
top
.
Manual,
semi-automatic,
and
fully
automatic
tops
have
similar
mechanical
construction
.

NOTE-

The
electronic
circuits
used
to
controlconvertible
top
operation
arecomplex
.
Diagnosis
of
the
convertible
top
and
the
Rollover
Protection
System
are
beyond
the
scope
of
this
book
.
Your
authorized
BMW
dealer
has
the
proper
diagnostic
equipment
and
tools
to
carry
out
these
tasks
.

Front
Latching
Mechanism

A
close,
tight
fit
between
the
front
bow
of
the
convertible

roof
and
the
top
of
the
windshield
is
critical
for
preventing

moisture
and
wind
noise
from
intruding
into
the
passenger

compartment
.

Visor
Latch
Plate

The
left
and
right
visor
latch
plates
can
be
accessed
by
re-

moving
the
trim
and
moldings
aroundthe
sides
and
top
of
the
windshield
.
Each
latch
is
attached
to
thetop
of
the
windshield
using
three
bolts
.
Latch
position
is
adjusted
as
follows
:

"
Loosen
bolts

Latch
top

"
Align
top

"
Retighten
bolts
.
See
Fig
.
7
.

POWER
CONVERTIBLE
TOP

4
a

0012756

Visor
Latch

0012768

Fig
.
7
.



Visor
latchplate
is
heldto
top
of
windshieldwiththreebolts
(arrows)
.

The
semi-automatic
and
the
fully
automatic
top
front
latches

are
of
similar
design
.
For
the
automatic
latching
mechanism

an
additional
motor
has
been
installed
in
the
front
bow
of
the
convertible
top
.
This
releases
the
top
from
the
visor
latch

plates
and
pulís
it
back
far
enough
for
the
main
retracting
mechanism
to
complete
thejob
.

The
latches
and
the
motor
can
be
accessed
byremovingthe
front
cover
trim
from
the
convertible
top
.

Convertible
Top
Lid

The
components
of
the
convertible
top
lid
are
shown
in
Fig
.
20
.

Fig
.
20
.
Components
of
the
convertible
top
lid
.

ROLLOVER
PROTECTION
SYSTEM

The
lid
latches
are
cable
operated
by
a
drive
motor
located
in
the
left
sideof
the
luggagecompartment,
behind
the
trim
lin-

er
.
The
same
motor
is
used
to
raise
and
lower
the
lid
during

automatic
convertible
topoperation
.

The
latch
cables
must
be
adjusted
so
that
the
lidfits
snugly
against
the
body
when
locked
.

The
lid
drive
motor
can
be
removed
and
replaced
from
the

luggage
compartment
.

Two
spring-locaed
cassettes
are
mounted
behind
the
rear
seat
.
A
single
rollover
sensor,
mounted
on
the
left
cassette,
signals
the
convertible
top
module
(CVM)
of
animminent
roll-
over,
whereupon
the
module
triggers
both
cassettes
within

3j10th
of
a
second
.
See
Fig
.
21
.

Once
the
cars
ignition
has
been
switched
on,
the
rollover

sensor
performs
a
self-test
lasting
6
seconds
.
During
this
time

a
yellow
warning
light
is
lit
on
the
dashboard
.
If
thewarning
lightfails
to
go
out
after
6
seconds,
this
means
that
a
fault
has

been
detected
in
the
system
.
The
fault
is
stored
in
the
CM

Faults
canbe
retrieved
and
diagnosedby
special
diagnostic

equipment
.

NOTE-

Diagnosis
of
the
convertible
top
and
the
Rollover
Pro-
tection
System
are
beyond
the
scope
of
this
book
.
Your
authorized
BMW
dealer
has
the
proper
diagnostic
equipment
and
tools
to
carry
out
these
tasks
.

CONVERTIBLE
TOP



541-
9

Fig
.
21
.
Construction
of
the
rollover
protection
cassette
.

After
deployment,
thedetent
pawl
in
a
rollover
protection
cassette
can
be
retracted
using
the
special
tool
in
the
tool
kit,
fitted
to
the
screwdriver
handle
.
The
rear
seatheadrest
needs
to
be
raised
for
this
procedure
.

WARNING
-

Ensure
that
the
area
above
and
adjacent
to
the
roll-
over
bars
remains
clear
and
unobstructed
at
all
times
.

CAUTION-

"
Itis
not
possible
to
close
the
convertible
top
with
the
rollover
bars
extended
.

"
If
a
hardtop
is
mounted,
be
sure
to
install
the
pro-
tective
rollover
bar
covers
provided
with
the
hard-
top
to
prevent
damaglng
the
rear
window
in
case
of
deployment
.

0012744

ROLLOVER
PROTECTION
SYSTEM

600-2



ELECTRICAL
SYSTEM-GENERAL

CAUTION
-

"
Always
turn
off
the
engine
and
disconnect
the

negative
()
cable
from
the
batterybefore
remov-

ing
any
electrical
components
.
Disconnecting
the

battery
may
erase
fault
code(s)
stored
in
control

module
memory
.
Check
for
fault
codes
using
spe-
cial
BMW
diagnostic
equipment
.

"
Prior
to
disconnecting
the
battery,
read
the
bat-

tery
disconnection
cautions
given
at
the
front
of

this
manual
onpage
viii
.

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

"
Do
not
disconnect
the
battery
with
engine
run-

ning
.

"
Do
not
quick-charge
the
battery
(for
boost
start-
ing)
for
longer
than
one
minute,
and
do
not
ex-
ceed
16
.5
volts
at
the
battery
with
the
boosting
cables
attached
.
Wait
at
feast
one
minute
before
boosting
the
battery
a
second
time
.

"
Do
not
usea
test
famp
that
has
a
normal
incan-

descent
bulb
to
test
circuits
contafning
electronic
components
.
The
high
electrical
consumptionof
these
test
lamps
may
damage
the
components
.

"
Do
not
use
an
analog
meter
.
Use
onfy
a
digital
multimeter
.

"
Many
of
the
solid-state
modules
are
static
sensi-
tive
.
Static
discharge
will
permanently
damage
them
.
Always
handle
the
modules
using
proper
static
prevention
equipment
and
techniques
.

"
To
avoid
damaging
harness
connectors
or
relay
panel
sockets,
use
jumper
wires
with
flat-blade
connectors
that
are
the
same
size
as
the
connec-
tor
or
relay
terminals
.

"
Always
switch
a
digital
multimeter
to
the
appropri-
ate
function
and
range
before
making
test
con-
nections
.

"
Do
not
tryto
start
the
engine
of
a
carwhich
has
been
heated
above176°F
(80°C),
(for
example,
in
a
paint
dryingbooth)
.
Allow
it
to
cool
to
normal
temperature
.

"
Disconnect
the
battery
before
dolng
any
electric
welding
on
the
car
.

"
Do
not
wash
the
engine
while
it
is
runnfng,
or
any-
time
the
ignition
is
switched
on
.

WIRING
DIAGRAMS

Electrical
Test
Equipment

Many
of
the
electrical
tests
described
in
this
manual
call
for

measuring
voltage,
currentorresistanceusing
a
digital
multi-

meter
(DMM)
.
Digital
meters
are
preferred
for
precise
mea-

surements
and
for
electronics
work
because
they
are
generally
more
accuratethan
analog
meters
.
The
numerical

display
is
alsoless
likely
to
be
misread,
since
there
is
no
nee-

dle
position
to
be
misinterpreted
by
reading
at
an
angle
.

An
LED
test
light
is
a
safe,
inexpensive
tool
that
can
be
used

to
perform
many
simple
electrical
tests
that
would
otherwise

require
a
digital
multimeter
.
The
LED
indicates
when
voltage

is
present
between
anytwo
test-points
in
a
circuit
.

CA
UTION-

"
Choose
test
equipment
carefully
.
Use
a
digital

multimeter
with
at
leadt
10
megaohm
input
im-

pedance,or
an
LED
test
light
.
An
analog
meter
(swing-need1e)
ora
test
light
with
a
normal
incan-
descent
bulb
may
draw
enough
current
to
dam-
age
sensitive
electronic
components
.

"
An
ohmmeter
must
not
beused
to
measure
resis-
tance
on
solidstate
components
suchas
controlunits
or
time
delay
relays
.

"
Always
disconnect
the
battery
before
making
re-

sístance
(ohm)
measurements
on
the
circuit
.

WIRING
DIAGRAMS

The
wiring
diagrams
shown
in
Electrical
Wiring
Diagrams

have
been
specially
designed
to
enable
quick
and
efficientdi-

agnosis
and
troubleshooting
of
electrical
malfunctions
.

Wiring
Codes
and
Abbreviations

A
lot
of
information
is
included
in
each
wiring
diagram
if
you
know
how
to
read
them
.
Wire
colors
in
the
diagrams
are
ab-

breviated
.
Combined
color
codes
indicate
a
multi-colored
wire
.
For
example
the
code
BLU/RED
indicates
a
Blue
wire

with
a
Red
stripe
.

Many
electrical
components,
connectors,
fuses,
and

ground
locations
are
identified
using
a
unique
number
.
Each

of
there
numbers
corresponds
to
a
particular
part
in
the
circuit
commonly
found
in
Electrical
Wiring
Diagrams
.