1992 BMW 325i ELECTRICAL WIRING

General
Data
and



010
FundamentalsfortheDo-lt-YourselfOwner

Maintenance



020
Maintenance
Program

Engine

Transmission

Suspension,

Steering
and

Brakes

4
Body

100
Engine-General

110



Engine
Removal
and
Installation
113



Cylinder
Head
Removal
and
Installation
116



Cylinder
Head
and
Valvetrain
117



Camshaft
Timing
Chain

119



Lubrication
System

200
Transmission-General
210
Clutch
230
Manual
Transmission

510



Exterior
Trim,
Bumpers



520



Seats

Bo
y
Equipment



512
DoorWTdws



540



nr
t

513



InteriorTrim



541



Convertible
Top

515



Central
Locking
and
Anti-Theft

600



Electrical
System-General



620



Instruments

Electrical
S



stem
610
Electrical
Component
Locations



630
Exterior
Lighting

611



Wipers
and
Washers



640



Heating
and
Air
Conditioning

6



612



Switches
and
Electrical
Accessories



650



Radio

Equipment
and



720
SeatBelts

Accessories



721
Airbag
System
(SRS)

Electrical
Wiring

Diagrams

Foreword
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Warnings
and
Cautions
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Index
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back
of
book

300



Suspension,
Steering
and



330



RearSuspension

Brakes-General



331



Final
Drive

310



Front
Suspension



340



Brakes

320



Steering
and
Wheel
Alignment

400
Body-General



411
Doors

410



Fenders,
Engine
Hood



412



Trunk
Lid

120



Ignition
System
121



Battery,Starter,
Alternator
130



Fue¡
Injection
160



Fuel
Tank
and
Fuel
Pump
170



Radiator
and
Cooling
System180



Exhaust
System

240



Automatic
Transmission
250



Gearshift
Linkage

260
Driveshaft

010-2



FUNDAMENTALS
FOR
THE
DO-ITYOURSELF
OWNER

HOW
TO
USE
THIS
MANUAL

A
note
contains
helpfulinformation,
tipsthat
will
hefp
in
The
manual
is
divided
into
ninesections
:



doinga
better
job
and
completing
!t
more
easíly
.

0
GENERAL
DATA
AND
MAINTENANCE

1
ENGINE

2
TRANSMISSION

3
SUSPENSION,
STEERING
AND
BRAKES

4
BODY

5
BODY
EQUIPMENT

6
ELECTRICAL
SYSTEM

7
EQUIPMENTANDACCESSORIES

ELECTRICAL
WIRING
DIAGRAMS

0
GENERAL
DATA
AND
MAINTENANCE
coversthe
rec-

ommended
maintenance
schedules
and
service
procedures

needed
to
perform
BMW
scheduled
maintenance
work
.
Also

within
this
section
is
the
010
Fundamentals
for
the
Do-It-

Yourself
Owner
section,
which
contains
basic
instructions,
tips
and
helpful
hints
for
do-it-yourself
maintenance
and
repair
.

The
next
seven
sections
(1
through
7)
are
repair
based
and

are
further
broken
down
into
three
digit
repair
groups
.
Each
ma-

jor
section
begins
with
a
General
repair
group,
e
.g
.
100En-

gine-General
.
These
"00"
(doublezero)
groups
aremostly

descriptive
in
nature,
covering
topics
suchas
theory
of
opera-
tion
and
troubleshooting
.
The
remainder
of
the
repair
groups

contain
the
more
involved
repair
information
.
The
last
major

section
contains
detailed
electrical
wiring
diagram
schematics
.

A
master
listing
of
the
9major
sections
and
the
correspond-
ing
individual
repair
groups
can
befoundon
the
inside
front
cover
.

Each
repair
group
begins
with
a
Table
of
Contents
listing
the

majos
subject
headings
within
the
group
.
Page
numbers

throughout
the
manual
are
organizedaccording
to
the
repair
groupsystem
.
For
example,
youcan
expect
tofind
repair
infor-
mation
on
brakes
(Repair
Group
340)
beginning
on
page
340-
1
.
A
comprehensive
index
can
be
found
at
the
back
of
the
man-

ual
.

Warnings,
Cautions
and
Notes
Throughout
this
manualare
many
passages
with
the
head-
ings
WARNING,
CAUTION,
or
NOTE
.
These
very
important
headings
have
diflerent
meanings
.

WARNING
-

The
text
under
this
heading
warns
of
unsafe
practic-
es
thatare
very
likelyto
cause
ínjury,
eitherby
dírect
threat
to
the
person(s)
pertorming
the
work
or
by
in-
creased
risk
of
accident
or
mechanfcal
fallure
whíle
driving
.

CAUTION-

A
caution
calls
attention
to
important
precautions
to
beobserved
during
the
repair
work
that
will
helo
prevent
accidentally
damaging
the
caror
its
parts
.

GETTING
STARTED

Safety

NOTE-

Please
read
every
WARNING,
CAUTION,
and
NOTE
at
the

front
of
the
manual
and
as
they
appear
in
repair
procedures
.

They
are
very
important
.
Read
them
before
you
begin
any

maintenance
or
repair
job
.

Some
WARNINGs
and
CAUTIONs
are
repeated
wherever

they
apply
.
Read
them
all
.
Do
not
skip
any
.
These
messages
are
important,
even
to
the
owner
who
never
intends
to
workon

thecar
.

GETTING
STARTED

Most
of
the
necessary
maintenance
and
minor
repair
that
an

automobile
will
need
canbe
done
with
ordinary
tools,
evenby

owners
with
little
or
no
experience
in
car
repair
.
Below
is
some

important
information
on
how
to
work
safely,
a
discussion
of

what
tools
will
be
needed
and
how
to
use
them
.

Although
an
automobile
presents
many
hazards,
common

sense
and
good
equipment
can
helo
ensure
safety
.
Many
acci-

dents
happen
because
of
carelessness
.
Pay
attention
and
stick
to
these
few
important
safety
rules
.

WARNING
-

"
Never
run
the
engine
in
the
work
area
unless
it
is
well-ventflated
.
Theexhaustshouldbe
vented
to
the
outside
.
Carbon
monoxide
(CO)
in
theex-
haust
kilts
.

"
Remove
all
neckties,
scarts,
loose
clothing,
or
jewelry
when
working
near
running
engines
or
power
tools
.
Tuck
in
shirts
.
Tie
long
haír
and
se-
cure
it
under
a
cap
.
Severe
injury
can
result
from
these
things
beíngcaught
in
rotating
parts
.

"
Remove
ríngs,
watches,
and
bracelets
.
Asíde
from
the
dangersof
moving
parts,
metallic
jew-
elry
conducts
electricity
and
may
cause
shorts,
sparks,
bums,
or
damage
to
the
electrical
sys-
tem
when
accidentally
contacting
the
battery
or
other
electrical
terminals
.

"
Disconnect
the
battery
negative
()
cable
when-
ever
working
on
ornear
the
fuel
system
or
any-
thlng
that
is
electrically
powered
.
Accidental
electrícal
contact
may
damage
the
electrical
system
or
cause
a
fire
.

010-
6



FUNDAMENTALS
FOR
THE
DO-ITYOURSELF
OWNER

In
places
where
a
shaft
mustpass
through
a
housing,
flexible
lip
seals
areused
to
keep
the
lubricating
oil
or
grease
from
leak-

ingout
past
the
rotating
shaft
.
Seals
should
never
be
reused

once
they
have
been
removed
.
When
removing
a
seal,
be
care-
ful
not
lo
scratch
or
otherwise
damage
the
metal
surfaces
.
Even
minor
damage
to
sealing
surfaces
can
cause
sea¡
damage
and
leakage
.

The
key
to
sea¡
installation
is
to
get
the
sea¡
in
straight
without

damaging
¡t
.
Use
a
sea¡
driver
that
is
the
same
diameter
as
the
seal
housing
to
gently
and
evenly
insta¡I
into
place
.
If
a
proper
size
seal
driver
is
not
available,
a
socket
of
the
right
size
will
do
.

When
installing
a
seal,
¡t
a
good
idea
to
coat
the
sea¡
with
o¡I

to
aid
installation
.
Some
seals
are
directional
and
special
instal-
lation
instructions
apply
.
Make
sure
¡t
is
installed
with
the
lip
fac-
ing
the
correct
way
.
Normally
the
lip
faces
the
inside
.
Note
the
installation
direction
of
the
old
sea¡before
removing
¡t
.

Electrical
Testing

Many
electrical
problems
canbe
understood
and
solved
with
only
a
little
fundamental
knowledge
of
how
electrical
circuits



Insulate
the
finished
connection
.
Electronics
stores
can
sup-
function
.



ply
heat-shrinkable
insulating
tubing
that
can
be
placed
onto
the
wire
before
connectiog,
slid
over
the
finished
joint,
and
Electric
current
only
flows
in
a
complete
circuit
.
To
operate,



shrunk
to
a
tight
fit
with
a
heat
gun
orhair
dryer
.
The
nextbest
every
electrical
device
in
thecar
requires
a
complete
circuit
in-



alternative
is
electrical
tape
.
Make
sure
the
wire
is
clean
and
cluding
a
voltage
source
and
a
pathto
ground
.
The
positive
(+)



free
ofsolder
flux
or
other
contamination
.
Wrap
the
joint
tightly
side
of
the
battery
is
the
original
voltagesource,
and
ground
is
to
sea¡
out
moisture
.
See
600
Electrical-General
for
more
in-
any
retum
path
to
the
negative
()
-
side
ofth
e
battery°
whether
li



formation
.
through
the
wiring
harness
or
thecar
body
.
Except
for
portions
of
the
charging
system,
al¡
electrical
current
in
the
car
is
direct
current
(DC)
and
flows
from
positive
(+)
to
negative
(-)
.



BVYING
PART$

Switches
are
used
to
turn
components
on
or
off
by
complet-
ing
or
interrupting
#he
circuit
.
A
switch
is
"open"
when
the
circuit



Many
of
the
maíntenance
and
repair
tasks
in
this
manual
cal¡
is
ínterrupted,
and
"closed"
when
the
circuit
is
completed
.
Fig
.
5



for
the
installation
of
new
parte,
or
the
use
of
new
gaskets
and

shows
a
basic
circuit
schematic
.
See600
Electrical
System-



other
materials
when
reinstalling
parts
.
Most
often,
the
parts

General
for
electrical
troubleshooting
.



that
will
be
needed
should
be
on
hand
beforebeginningthe
job
.
Read
the
introductory
text
and
the
complete
procedure
to
de-
termine
which
parts
will
be
needed
.

B029ELG

Fig
.
5
.



Schematic
representation
of
simple
circuit
for
light
bulb
.
Igni-
tion
switch
is
shown
closed,
making
circuit
complete
.

BVYING
PARTS

Wire
Repairs

Repairs
to
a
wiring
harness
requirespecial
care
to
make
the

repair
permanent
.
The
wire
endsmust
be
clean
.
lf
frayedor
oth-

erwise
damaged,
cut
off
the
end
.
If
the
wire
is
too
short,
splice
in

a
new
piece
of
wire
of
the
same
size
and
make
two
connec-
tions
.

Use
connectors
that
are
designed
for
the
purpose
.
Crimped-

on
or
soldered-onconnectors
are
best
.
Crimp
connectors
and

special
crimping
pliers
are
widely
available
.
If
soldering,
use

needlenose
pliers
tohold
the
wire
near
the
solder
joint
and
cre-
ate
a
"heat
dam"
.
This
keeps
the
heat
and
the
solder
from
trav-
eling
up
the
wire
.
Always
use
a
solder
made
specifically
for
electrical
work
(rosin
core)
.

NOTE-

Twisting
wirestogether
to
make
a
repair
is
not
recom-
mended
.
Corrosion
and
vibration
will
eventually
spoil
the
connection
and
may
lead
to
irreparable
damage
to
sensitive
electronic
componente
.

NOTE-

For
some
bigger
jobs,
partial
disassembly
and
inspec-
tion
are
required
to
determine
acomplete
parts
list
.
Read
the
procedure
carefully
and,
if
necessary,
make
other
arrangements
to
get
the
necessary
parts
while
your
car
is
disassembled
.

Genuine
BMW
Parts

Genuine
BMW
replacement
parts
from
an
authorized
BMW
dealer
are
designed
and
manufactured
lo
the
same
high
stan-
dards
as
the
original
parts
.
They
will
be
the
correct
material,
manufactured
to
the
same
specifications,
and
guaranteed
lo
fit
and
work
as
intended
by
the
engineers
who
designed
thecar
.
Some
genuine
BMW
parts
have
a
limited
warranty
.

Solt
Diameter
and
Wrench
Size
"
M5
.
...
............
....
......
.
.......
8
mm

"
M6
.
.
..............
.
.
...
...........
.10
mm

"
M8
.
.
..............
.
.
..
.....
12mmor13mm

"
M10
..
.............
.
.
...
...........
.17
mm

"
M12
...
...........
..
.
..
............
.19
mm

"
M14
.
..:
.
.........
..
.
..
.............
22
mm

Spark
Plug
Socket
.
A
special
socket
for
spark
plugs
is
the

correct
size,
is
deep
enough
to
accommodate
a
spark
plug's

length,
and
includes
a
rubber
insertto
both
protect
the
spark

plug
from
damage
and
grip
it
for
easier
removal
.
See
Fig
.
9
.

Fig
.
9
.



Spark
plug
socket
.

FUNDAMENTALS
FOR
THEDO-ITYOURSELF
OWNER
010-
9

B003FNG

Pliers
.
A
few
of
the
many
types
ofpliers
are
shown
in
Fig
.
10
.

Mostare
used
for
holding
irregularobjects,
bending,or
crimp-

ing
.
Some
have
special
applications
.

A
needlenose
plier
is
used
for
gripping
small
and
poorly
ac-

cessible
objects,
and
is
useful
for
wiring
and
other
electrical

work
.
A
locking
plier
suchas
theVise-Grip
®
is
useful
because

of
its
tightgrip
.

Snap-ring
and
circlip
pliers
withspecial
tipped
jacas
areused
lo
remove
and
install
snap-ringsor
circlips
.
A
Channel-lock®
or
water
pump
plier
has
adjustable
jacas
that
can
be
quickly

changed
to
match
the
size
of
the
object
being
held
to
give
great-
erleverage
.

An
adjustable
wrench
canbea
useful
addition
to
a
small
tool

kit
.
See
Fig
.
11
.
It
can
substitute
in
a
pinch,
if
two
wrenches
of

the
same
size
are
needed
lo
remove
a
nut
and
bolt
.
Use
extra
care
with
adjustable
wrenches,
as
they
tend
to
loosen,
slip,
and
damage
fasteners
.

Fig
.
11
.
Adjustable
wrench
.

B008FNG

Compared
to
a
wrench
of
the
correct
size,
an
adjustable

wrench
is
always
second
best
.
They
shouldonly
beused
when

the
correct
size
wrench
is
not
available
.
Choose
one
of
average

size
range,
about
6
to
8
inches
in
length
.

Jack
Stands

Strong
jack
stands
are
extremely
important
for
any
work
that

is
done
under
thecar
.
Use
onlyjack
stands
that
are
designed

for
the
purpose
.
Blocks
of
wood,
concrete,
bricks,
etc
.
arenot

safeor
suitable
substitutes
.

WARNING
-

A
jack
should
be
used
only
to
raise
the
vehicle
and
shouldnot
beused
to
support
the
car
for
a
long
pe-
riod
.
Always
use
jack
stands
to
support
a
raised
ve-
hicle
.

Jack
standsare
available
1n
severa¡
styles
.
A
typical
jack

stand
is
shown
in
Fig
.
12
.
The
best
ones
are
made
of
heavy
ma-

terial
for
strength,
have
a
wide
base
for
stability,
and
are

equipped
lo
positively
lock
in
their
raised
positions
.
Get
the
best

ones
available
.

Oil
Change
Equipment

Changing
engine
oil
requires
a
17mm
socket
or
wrench
to

BOO6FNG-



loosen
and
tighten
the
drain
plug
and
a
drain
pan
(at
least
8
qt
.

capacity)
.
An
oil
filter
wrench
is
not
required
.
These
items
are
Fig
.
10
.
Pliers
.
From
left,
snap-ring,



needlenose,
adjustable-joint



shown
in
Fig
.
13
.
A
wide,
loca
drain
pan
wíll
fit
more
easily
under

(Channellock©),
slip-joint,
and
locking(Vise-Grip®)
.



the
car
.
Use
a
funnel
lo
pour
the
new
oil
into
theengine
.

TOOLS

NOTE-

"
On
carswith
OBD
ti,
specialized
OBD
11
scan
tool
equipment
must
be
used
to
access
the
DTCs,
either
using
the
BMW
special
tool
ora
`generic"
OBD
11
scan
tool
.
See
130
Fuel
Injection
.

"
The
08D
11
fault
memory
(including
an
iiluminated
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
.

Table
d
.
OBD
1
Fault
(Blink)
Codes

(1992-1995
modeis
only)

Graphic
representation
of
flashing
Check
Engine
light
fault
code
:
1221
5
Seconds
.
:-



2
.5~-

--05--

Fault
code
and
meaning



1
Corrective
action

Code
1216
:
Throttle
potentiometer

Code
1218
:
Output
stage,
group#1
(DME
3
.3
.ionly)

Code
1219
:
Output
stage,
group
#2
(DME
3
.3.1
only)

Code
1221
:
Oxygen
sensor
#1

Code
1224
:
Air
temperature
sensor
(NTC)

Code
1226
:
Knock
sensor
#2
(DME
3
.3
.1
only)

130

ENGINE-GENERAL
100-
9

2
.5
seconds,
then
go
off
for
2
.5
seconds
.
At
thispoint,
the
fault
codes
will
begin
to
flash
.
See
Table
d
.

If
more
than
one
fault
has
been
detected,
eachcode
will
be
separated
by
a2
.5
second
pause
.
When
al¡
fault
codes
havebeen
displayed,
there
will
be0
.5
second
flash
and
thenthe
light
will
remain
off
.
To
read
the
codes
again,
turn
the
key
off
and
then
on
again
.
Depress
theaccelerator
pedal
to
the
floor
five
times
quickly
(within
5
seconds)
.
The
codes
will
begin
to
repeat
.

On
cars
with
OBD
I,
fault
codes
can
be
read
by
turning
the



To
erase
the
fault
code
memory,
first
make
sure
the
fault

ignition
key
on
and
fully
depressing
theaccelerator
pedal
to



code
1000
(short
blink
and
then
light
goes
out
for
long
period)

the
floor
five
times
within
five
seconds
.
TheCheck
Engine



is
present,
then
depress
the
throttle
fully
for
at
least
10
sec-

light
will
then
remain
on
for
five
seconds,
blink
off,
come
on
for



onds
.
Read
the
fault
codes
as
described
earlier
and
check
for
the
1444
code
(no
faults
stored)
.

-,--------------
Check
Engine
light
on

Check
Engine
light
off

Code
1211
:
DM
E
Control
Module



DME
control
module
may
be
faulty
.
This
code
appears
if
the
control
module
fails
the
self
test
.
Check
inputsto
control
module
.
Repair
Group
130

Code
1215
:
Mass
air
flow
sensor



Check
air
flow
or
mass
air
flow
sensor
and
wiring
to
sensor
.
Repair
Group
130

Test
throttle
potentiometer
resistance
and
wiring
.
Repair
Group
130

Test
DME
control
module
input/outputs
.
Repair
Group
130

Test
DME
control
module
input/outputs
.
Repair
Group
130

Check
sensor
output
signal
to
DME
control
module
.
Repair
Group

Code
1222
:
Oxygen
sensor
lean/rich
control
stop



Check
for
intake
air
leaks
or
reasons
forrich
míxture
.
See
Driveabil-
ity
Troubleshooting
given
earlier
in
this
repair
group

Code
1223
:
Coolant
temperaturesensor
(NTC)



1
Test
coolant
temperature
sensor
.
Repair
Group
130

Test
intake
air
temperature
sensor
.
Repair
Group
130

Code
1225
:
Knock
sensor#1
(DME
3
.3
.1
only)



1
Check
knocksensorand
sensor
wiring
.
Repair
Group
120

Check
knocksensor
and
sensor
wiring
.
Repair
Group
120

Code
1231
:
Batteryvoltage
monitor



Test
battery
voltage
and
battery
check
charging
system
and
starter
.
Repair
Group
121

Code
1234
:
Speedometer
"A"signal
(DME
3
.3
.1
only)



Check
wiring
between
instrument
cluster
and
DME
control
module
.
Electrical
Wiring
Diagrams

Code
1237
:
A/C
compressor
cutoff
(DME
3
.3
.1
only)



Test
DME
control
module
inputs/outputs
from
A/C
system
.
Repair
Group
130

Code
1242
:
A/C
compressor
signal
(DME
3
.3.1
only)



Test
DME
control
module
inputs/outputs
from
A/C
system
.
Repair
Group
130

DRIVEABILITY
TROLIBLESHOOTING

100-
1
0
ENGINE-GENERAL

Table
d
.
OBD
I
Fault
(Blink)
Codes
(continued)

(1992-1995
modeis
only)

Graphic
representation
of
flashing
Check
Engine
light
fault
code
:
1221
-
;
5
Seconds
.
;--~
2
.5
r
----------------
Check
Engine
light
on

Fault
code
and
meaning



Corrective
action

Check
Engine
light
off

Code
1243
:
Crankshaft
position
sensor
(DME
3
.3
.1
only)



Test
crankshaft
position/rpm
sensor
and
wiring
from
sensor
lo
DME

control
module
.
Repair
Group
120

Code
1244
:
Camshaft
position
sensor
(DME
3
.3
.1
only)



Test
camshaft
position
sensor
and
wiring
fromsensor
to
DME
con-
trol
module
.
Repair
Group
130

Code
1245
:
Electronic
transmission
control
intervention
(DME
3
.3
.1



Check
wiring
between
DME
control
module
and
auto
.
transmission
only)



control
module

Code
1247
:
Ignition
secondary
monitor
(DME
3
.3
.1
only)



Check
secondary
voltage
lo
ignition
coils
.
Check
wiringat
ignition

coils
.
Repair
Group
120

Code
1251
:
Fuel
injector
#1
(DME
3
.113
.3
.1
only)



1
Test
injector
operation/signal
lo
injector
.
Repair
group130

Code
1252
:
Fuel
injector
#2
(DME
3
.113
.3
.1
only)



Test
injector
operation/signal
lo
injector
.
Repair
group130

Code
1253
:
Fuel
injector
#3
(DME
3
.1/3
.3
.1
only)



Test
injector
operation/signal
to
injector
.
Repair
group130

Code
1254
:
Fuel
injector
#4
(DME
3
.1/3
.3
.1
only)



Test
injector
operation/signal
to
injector
.
Repair
group
130

Code
1255
:
Fuel
injector
#5
(DME
3
.1/3
.3
.1
only)



Test
injector
operation/signal
to
injector
.
Repair
group130

Code
1256
:
Fuel
injector
#6
(DME
3
.1/3
.3
.1
only)



Test
injector
operation/signal
lo
injector
.
Repair
group130

Code
1261
:
Fuel
pump
control



Test
fuel
pump
relay
and
fuel
pump
circuit
.
Repairgroup
160

Code
1262
:
Idle
speed
control



Test
idleair
controlvalve
and
signalto
valve
.
Repair
Group
130

Code
1263
:
Fuel
tank
evaporative
(EVAP)
system



Test
EVAP
purge
valve
.
Repair
Group
160

Code
1264
:
Oxygen
sensor
heater



1
Test
oxygen
sensorheater
and
heater
relay
.
Repair
group
130

Code
1265
:
Check
engine
lamp
(DME
3
.3.1
only)



1
Test
for
faulty
bulb
or
wiring
.
Electrical
Wiring
Diagrams

Code
1266
:
VANOS
(DME
3
.3
.1
only)



1
Test
VANOS
solenoid
.
Check
for
signal
to
VANOS
solenoid
.

Code
1267
:
Air
pump
relay
control
(DME
3
.3
.1
only)



Test
air
pump
relay
and
wiring
(where
applicable)
Electrical
Wiring
Diagrams
Code
1271
:
Ignition
coil
#1
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
toignitioncoil
.
Repair
Group
120

Code
1272
:
Ignition
coil
#2
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
loignitioncoil
.
Repair
Group
120

Code
1273
:
Ignition
coil
#3
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
loignitioncoil
.
Repair
Group
120

Code
1274
:
Ignítion
coil
#4
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
toignitioncoil
.
Repair
Group
120

Code
1275
:
Ignitioncoil
#5
(DME
3
.3.1
only)



Test
ignition
coil
and
wiring
loignitioncoil
.
Repair
Group
120

Code
1276
:
Ignition
coil
#6
(DME
3
.3.1
only)



Test
ignitioncoil
and
wiring
loignitioncoil
.
Repair
Group
120

Code
1281
:
DME
control
module
memory
supply
(DME
3
.3
.1
only)



Check
voltage
supply
from
battery
lo
DME
control
module
.
Electri-

Code
1282
:
Fault
code
memory
(DME
3
.3.1
only)



Check
DME
control
module
inputs/outputs
.
Control
module
may
be
faulty
.
Repair
Group
130

Code
1283
:
Fuel
injector
output
stage
(DME
3
.3
.1
only)



Check
DME
control
module
inputs/outputs
.
Control
module
may
be
faulty
.
Repair
Group
130

DRIVEABILITY
TROUBLESHOOTING

cal
Wiring
Diagrams

If
a
battery
cableconnection
hasno
visible
faults,
but
is
still
suspect,
measure
the
voltage
drop
across
the
connection
.
A
large
drop
indicates
excessive
resistance,
meaning
the
con-
nection
is
corroded,
dirty,
or
damaged
.
Clean
or
repair
the
connection
and
retest
.

NOTE-

For
instructions
on
conducting
a
voltage
drop
test,
and
other
general
electrical
troubleshooting
information,
see600
Electrical
System-General
.

Wiring
and
Harness
Connections

The
electronic
fuel
injection
and
ignition
systems
operate
at

low
voltage
and
current
values,
making
them
sensitive
to

small
increases
in
resistance
.
The
electrical
system
is
routine-

ly
subjected
to
corrosion,
vibration
and
wear,
so
faults
or
cor-

rosion
in
the
wiring
harness
and
connectors
are
common
causes
of
driveability
problems
.

Visually
inspect
all
wiring,
connectors,
switches
and
fuses
in
the
system
.
Loose
or
damaged
connectors
can
cause
inter-

mittent
problems,
especially
the
smallterminals
in
the
ECM

connectors
.
Disconnect
the
wiring
harness
connectors
to

check
for
corrosion
;
and
use
electrical
cleaning
spray
to
re-

move
contaminants
.
Often,
simply
disconnecting
and
recon-

necting
a
dirty
connector
several
times
will
clean
the
terminals
and
help
to
reestablish
good
electrical
contact
.

If
a
wiring
harnessconnectorhasno
visible
faults,
but
is
still

suspect,
measure
the
voltage
drop
across
the
connector
.
A

large
drop
indicates
excessive
resistance,
meaning
the
con-

nector
is
corroded,
dirty
or
damaged
.
Clean
or
repair
the
con-

nector
and
retest
.

Ground
Connections

For
any
electrical
circuit
to
work,
it
must
make
acomplete

path,
beginning
at
the
positive
(+)
battery
terminal
and
ending

at
the
negative
(-)
terminal
.
The
negative
(-)
battery
cable
is

attached
to
the
car's
chassis
.
Therefore,
any
wireor
metal

part
attached
to
the
chassis
provides
a
good
ground
path
back

to
the
negative
(-)
battery
terminal
.

Poorground
connections
are
amajor
source
of
driveabílity

problems
.
If
any
of
themainground
connections
for
the
igni-
tion
system
or
the
fuelinjection
system
are
faulty,
the
in-

creased
resistance
in
that
circuit
will
cause
problems
.

Visually
inspect
al¡
ground
wires
and
connections
for

breaks,
looseness
or
corrosion
.
Be
careful
because
wires

sometimes
break
internally
or
in
areas
not
easily
visible
.
The

main
grounds
for
the
DME
system
are
shown
in
Fig
.
11,Fig
.

12,
and
Fig
.
13
.
Also
check
the
main
fuel
pump
ground
in
the
center
console,
below
the
emergency
brake
handle
.

If
a
ground
connection
has
no
visiblefaults,
but
is
still
suspect,

measure
the
voltage
drop
acrossthe
connection
.
A
large
drop

indicates
high
resistance,
meaning
the
connection
is
corroded,

dirty
or
damaged
.
Clean
or
repair
the
connection
and
retest
.

ENGINE-GENERAL
100-
1
3

UU,~uyi

Fig
.
11
.
Mainground
(arrow)
for
engine
management
system
.
Grounds
are
in
right
rear
of
engine
compartment
.

Fig
.
12
.
Mainground
for
ignition
coils
on
MS
41
.1
engine
manage-
ment
system
(arrow)
.

DRIVEABILITY
TROLIBLESHOOTING

11
.
Detach
wiring
harness
duct
at
rear
bulkhead
panel
and
pull
complete
duct
forward
and
up
to
allow
access
to
rear
of
cylinder
head
cover
.

12
.
Remove
spark
plugs
and
spark
plugwire
loom
.

"
Remove
plastic
cover
from
top
of
cylinder
head
.

"
Disconnect
spark
plug
wires
fromspark
plugs
and
re-

move
spark
plugs
.
"
Unbolt
spark
plug
cable
harness
and
heat
shield
from
right
side
of
cylinder
head
cover
and
set
aside
.

13
.
Unscrew
andremove
cylinder
head
cover
cap
screws

and
remove
cover
.
See
Fig
.
5
.

CAUTION-

Two
of
the
cover
hold-down
screws
are
under
the
spark
plug
cable
duct
.

NOTE-

Make
note
of
the
arrangement
of
cap
screws,
washers
and
rubber
grommets
holding
the
cylinder
head
cover
in
place
.

Fig
.
5
.



Cylinder
head
cover
mounting
points
(arrows)
.

Fig
.
7
.



M44
fuel
rail
air
connection
(A)
and
fuel
supply
and
return
lines
Intake
manifold,
removing



(B)
.

14
.
On
late
engines,
disconnect
injector
air
shrouding
hose

from
fitting
at
center
of
upper
intake
manifold
.



18
.
Disconnect
fuel
supply
and
return
lines
from
fuel
rail
.

15
.
Remove
upper
section
of
intake
manifold
.

"
Disconnect
ali
cables
harness
connectors
from
throttle

housing
and
intake
manifold
.

"
Disconnect
fuel
tank
vent
hose
fromvent
valve
on
low-

er
sitie
of
manifold
.

"
Remove
manifold
support
brackets
.
See
Fig
.
6
.

"
Remove
upper-to-lower
manifold
fasteners
(1
bolt,
2

nuts)
and
separate
upper
manifold
from
lowermani-

fold
.

Note
locating
dowei
sleeves
on
lower
to
upper
manifold
mounting
studs
.
Remove
dowels
and
set
aside
.
See
Fig
.
8
.

CYLINDER
HEAD
REMOVAL
AND
INSTALLATION



113-3

0012686

Fig
.
6
.



Intake
manifold
support
brackets
and
mountinghardware
.
Manifold
for
M44
engine
shows
.

16
.
Disconnect
oil
dipstick
tube
bracket
from
lower
manifold
section
.

17
.
On
M44
engine,
relieve
fuel
pressure
using
com-

pressed
air
(maximum
3
bar
pressure)
at
schroeder

valve
on
fuel
rail
.
Briefly
apply
air
pressure
to
force
fuel

back
intofuel
tank
.
See
Fig
.
7
.

WARNING
-

"
The
fuel
system
retains
fuel
pressure
when
the
engine
is
off
(up
to
75
psi)
.
Use
care
when
dis-
connecting
fuel
lines
.
Unscrew
the
fuel
tank
cap
to
retease
pressure
in
the
tank
.
Wrap
a
clean
shop
towel
around
the
fitting
when
loosening
.

"
Fuel
is
highly
flammable
.
When
working
around
fuel,
do
not
disconnect
any
wires
that
could
cause
electrical
sparks
.
Do
not
smoke
or
worknear
heaters
or
other
tire
hazards
.
Placea
tire
extin-
guisher
in
the
vicinity
of
the
work
area
.

19
.
Disconnect
coolant
hoses
from
vent
valve
on
lower
intake

manifold
.
Remove
crankcase
vent
valve
from
manifold
.

CYLINDER
HEAD,
4-CYLINDER