1997 BMW 318i air

119-2



LUBRICATION
SYSTEM

NOTE-
Component
Location



If
the
light
does
not
go
out,
thewiring
to
theswitch
is"
Oil
pressure
switch



most
likely
grounded
somewhere
between
the
switch

all
engines
.......
...
.
..
......
ora
oil
filter
housing



terminal
and
the
warning
light
.
Sea
Electrical
Wiring

Diagrams
atrearof
manual
for
electrical
schematics
.

CAUTION-

Some
oil
may
drain
out
as
the
oil
pressure
switch
is
removed
.
Use
a
rag
to
soak
up
any
spills
.

2
.
Install
pressure
gauge
in
place
of
switch
.

3
.
With
gauge
instalied,
start
engine
and
allow
to
reach

operating
temperature
.
Check
oil
pressureboth
cold

and
hot
.

NOTE-

For
the
most
accurate
test
results,
the
engine
oil
(and
filter)
shouldbe
newand
of
the
correct
grade
.

Oil
Pressure

"
¡dle
(mínimum)
..
.
.
..............
.
.
0
.5
bar
(7psi)

"
Regulated
pressure
(elevated
engine
speed)

4-cylinder
engines
..
......
4
.3
±
0
.2
bar
(63
t3
psi)

6-cylinder
engines
.
.
.............
.
4
.0
bar
(59
psi)

4
.
Remove
pressure
gauge
and
reinstall
pressure
switch
.

If
testing
shows
low
oil
pressure,
one
or
more
of
the
follow-

ing
conditions
may
be
indicated
:
OIL
PAN

"
Worn
or
faulty
oii
pump
.

"
Worn
or
faulty
engine
bearings



The
oil
pancan
be
removed
with
the
engine
instalied,
al-

Severe
engine
wear
.



though
specíal
enginesupport
equipment
will
be
needed
.

Al¡
of
these
conditionsindicate
the
need
for
major
repairs
.

Oil
pressure
warning
system,
testing

When
the
ignition
is
tumed
ora,
the
oil
pressure
warning
light

comes
ora
.
When
the
engine
ís
started
and
the
oil
pressure
ris-

es
slightly,
the
oil
pressure
switch
opens
and
thewarning
light

goes
out
.
Make
sure
the
oil
leve¡
is
correct
before
making

tests
.

1
.
Turra
ignition
switch
ora
.

"
Warning
light
ora
instrument
panel
must
light
up
.

2
.
Remove
connector
from
oil
pressure
switch
.

"
Warning
light
ora
instrument
panel
must
go
out
.

OIL
PAN

3
.
If
warning
light
does
not
light
when
ignition
is
ora,
re-

move
connector
from
oil
pressure
switch
anduse
a

jumper
wire
to
ground
connector
terminal
to
a
clean

metal
surface
.

NOTE
-

If
the
warning
light
comes
ora,
check
the
switch
as
de-
scríbed
in
the
nextstep
.
If
the
warning
light
does
not
come
ora,
thewiring
to
the
instrument
cluster
or
to
the

light
itself
isfaulty
.

4
.
To
test
switch,
connect
ara
ohmmeter
between
terminal

in
switch
body
and
ground
.
With
engine
off,
these

should
be
continuity
.
With
engine
running,
oil
pressure

should
opera
switch
and
there
should
beno
continuity

Replace
a
faulty
switch
.

WARNING
-

Keep
in
mind
that
low
oil
pressure
may
be
prevent-

ing
the
switch
from
tuming
the
light
out
.
If
the
light

remains
ora
while
the
engine
is
running,
check
the

oil
pressure
asdescribed
earlier
.
Do
not
drive
the
car
until
the
problem
is
corrected
.
Theengine
may
be
severely
damaged
.

Oil
pan,
removing
and
installing

(4-cylinder
engines)

1
.
Raise
car
arad
place
securely
ora
jackstands
.

2
.
Remove
splash
shíeld(s)
from
under
engine,
where
ap-

plicable
.

3
.
Drain
engine
oil
as
described
in
020
Maintenance
Pro-
gram
.

4
.
Disconnect
vacuum
hose
adapter
from
vacuum
brake

booster
at
rear
of
engine
compartment
.

5
.
Remove
oil
dipstick
guide
tube
mounting
nut
and
pull
guide
tube
from
oil
pan
.
See
Fig
.
2
.

119-
4



LUBRICATION
SYSTEM

15
.
Remove
oil
pan
screws
.
Lower
andremove
oil
pan
to-

ward
rear
.



Tightening
Torques

"
Control
arm
bushing
carrier

CAUTION-



to
body(M10
bolt)
...............
42
Nm
(31
ft-Ib)

'



lf
the
oil
pan
does
not
separate
easily
from
the
en-



"
Engine
mount
to

gine
cylinder
block,
make
sure
all
mounting
bolis



suspension
crossmember
(M10
nut)
.
42
Nm
(31
ft-Ib)

have
been
removed
.
If
necessary,
a
few
tapswith



"
Front
suspension
crossmember
a
rubber
mallet
shouldbreak
it
free
.
Never
pry
the



to
body
.
.
..
...
..
.
....
See
310
Front
SusPension
oil
pan
loose
.
"
Oil
pan
to
engine
block
(M6
bolt)

8
.8
grade
..
....
.
...
...
.
........
10
Nm
(89
in-lb)
16
.
Installation
is
reverse
of
removal
.



10
.9
grade
...
..
.
....
..
.
.
.
.......
12
Nm
(9
ft-Ib)

"
Thoroughly
clean
all
old
gasket
material
from
mating



"
Power
steering
pump
to
bracket

surfaces
anduse
a
new
gasket
.



(self-locking
nuts)
....
..
.
....
..
.
..
22
Nm
(16
ft-Ib)

"
Applya
small
amount
of
non-hardening
sealer
(3-



"
Power
steering
pump
bracket
to
engine

Bond
O
l209
or
equivalent)
to
oil
pan
gasket
directly



block
or
oil
pan
(self-locking
nuts)
..
.
22
Nm
(16
ft-Ib)

below
joints
for
end
cover
and
front
timing
case
cover
.



"
Stabilizer
bar
link
to
control
arm
See
Fig
.
5
.



M8
nut
.................
...
.
...
22
Nm
(17
ft-Ib)
"
When
installing
oil
pan
to
engine,
tighten
forward



M10
nut
.....................
..
42
Nm
(31
Ib-ft)
screws
first,
then
tightenrear
.



"
Steering
column
universal
joint
"
Fill
engine
with
oil
as
described
in
020
Maintenance



to
steering
rack
spindle
(M8
bolt)
....
19
Nm
(14
ft-ib)
Program
.

0011950

Fig
.
5
.



Joint-mating
areas
at
oil
pan
gasket
where
sealer
should
be
applied
(arrows)
.
Apply
a
bead
3
mm
wideby
2
mm
high
.

OIL
PAN

WARNING
-

Always
use
new
bolis
when
mounting
the
subframe
to
the
body
.
The
one-timeonly
bolis
shouldbe
re-
placed
any
timethey
are
removed
.

NOTE-

The
oil
pickup
is
attached
to
the
oil
pan
using
self-tap-
ping
screws
.
For
this
reasonno
threading
for
the
pickup
is
present
on
new
oil
pans
.
Replace
the
seal
for
the
pickup
and
use
the
oíd
screws
to
rea
ttach
the
pickup
to
the
pan
.

Oil
pan,
removing
and
installing

(6-cylinder
engine,
1992models)

NOTE-

Cars
built
up
to
9/92
(1992models)usea
different
sus-
pension
crossmember
than
later
production
cars
.
Oil
pan
removalprocedureon
the
earlier
cars
requires
that
the
engine
be
raised
and
supportedfrom
above
.

1
.
Raise
car
and
place
securely
on
jackstands
.

2
.
Remove
splash
shield(s)
from
under
engine,
where
ap-

plicable
.

3
.
Drain
engine
oil
as
described
in
020
Maintenance
Pro-

gram
.

4
.
Remove
complete
exhaust
system
.
See180
Exhaust

System
.

5
.
Remove
air
filter
housing
complete
with
mass
air
flow

sensor
.
See
113
Cylinder
Head
Removal
and
Instal-

lation
.

6
.
Remove
alternator
cooling
duct
from
alternator
and
ra-
diator
support
.

7
.
Remove
radiator
cooling
fan
and
fan
shroud
.
Remove

radiator
securing
clips
at
top
of
radiator
.
See
170
Radi-

ator
and
Cooling
System
.

Center
the
steering
spindle
to
the
steering
rack
before
in-



NOTE-

stalling
the
steering
column
shaft
.
See
320
Steering
and



The
radiator
cooling
fan
nut(32
mm
wrench)
has
left

Wheel
Alignment
for
specific
installation
markings
and
pro-



hand
threads
.

cedures
.

8
.
Remove
air
plenum
from
rear
of
engine
compartment
.
See
640
Heating
and
Air
Conditioning
.

9
.
Release
drive
belt
tension
and
remove
alternator
drive
belt
.
Remove
A/C
compressor
drive
belt
.
See
Fig
.
6
.

B11143
Fig
.
6
.



To
remove
poly-ribbed
drive
belt,
pry
cover
from
front
of
ten-
sioner
.
Then
using
8
mm
hex
key,
turntensioner
clockwise
(arrow)
torelease
tension
and
slip
belt
off
pulleys
.

10
.
Unbolt
power
steering
reservoir
and
pull
reservoir
off
engine
mount
bracket
.

11
.
Without
disconnecting
fluid
lines,
remove
power
steer-
ing
bracket
(with
pump)
from
oil
panand
engine
block
.
See
Fig
.
7
.
Disconnect
fluid
lines
from
bracket
on
en-
gine
mount
.
Hang
pump
from
chassis
using
wire
.

12
.
Without
disconnecting
refrigerant
lines,
remove
A/C
compressor
from
engine
block
.
Hang
compressor
from
chassis
using
wire
.
See
640
Heating
and
Air
Condi-
tioning
.

13
.
Remove
oil
dipstick
guide
tube
mounting
bolt
and
re-
move
tube
.
See
Fig
.
8
.

NOTE-

The
guide
tube
is
sealed
in
the
oil
pan
with
an
O-ring
.
Check
that
the
O-ring
comes
out
with
the
tube
.
Use
anew
O-ring
when
installing
the
tube
.

14
.
On
cars
with
automatic
transmission,
remove
brackets
holding
ATF
cooler
linesto
oil
pan
and
cylinder
block
.

LUBRICATION
SYSTEM



119-
5

Fig
.
7
.



Power
steering
pump
mounting
bolts
(arrows)
.

Fig
.
8
.



Oil
dipstick
guide
tube
being
removed
.
Usea
new
O-ring
(arrow)
during
installation
.

15
.
Insta¡¡
engine
lifting
equipment
at
front
engine
lifting
point
and
raise
engine
just
until
its
weight
is
supported
.

16
.
Remove
nuts
at
bottom
of
left
and
right
engine
mounts
.
Remove
ground
wire
from
right
engine
mount
.
1-oosen
nuts
at
top
of
left
and
right
engine
mounts
(do
not
re-
move)
.

OIL
PAN

5
.
Remove
air
filter
housingcomplete
with
mass
air
flow
sensor
.
See113
Cylinder
HeadRemoval
and
Instal-
lation
.

6
.
Remove
oil
dipstick
guide
tube
mounting
bolt
.
Discon-
nect
oil
separator
hose
frombase
of
guide
tube
and
re-
move
tubefrom
oil
pan
(where
applicable)
.
See
Fig
.
10
.

NOTE-

The
guide
tube
is
sealed
in
the
blockusing
an
O-ring
.
Check
that
the
O-ring
comes
out
with
the
tube
.
Use
a
new
O-ring
when
installing
the
tube
.

Fig
.
10
.
Oil
dipstick
guide
tube
being
removed
.
Use
new
O-ring
(ar-
row)
during
installation
.

7
.
M50/S50US
engine
:
Using
a
clean
syringe,
remove
power
steering
fluid
from
fluid
reservoir
.
Disconnect
power
steering
fluid
lines
from
steering
rack
.
See
320
Steering
and
Wheel
Alignment
.

8
.
M52/S52US
engine
:
Unbolt
power
steering
reservoir
from
engíne,
then
tie
to
chassis
with
wire
.

9
.
Insta¡¡
engine
lifting
equipment
atfront
engine
lifting
point
and
raise
engine
approximately
5
mm
('/a
inch)
until
engineweight
is
supported
.
See
Fig
.
11
.

10
.
Workingbeneath
car,
separate
steering
column
shaft
from
steeringrack
at
universal
joint
.

"
Mark
steering
column
shaft
jointto
steering
rack
spin-

dle
.
Point
wheels
straight
ahead
before
disconnecting
shaft
from
rack
.
See
320
Steering
and
Wheel
Align-
ment
.

LUBRICATION
SYSTEM



119

Fig
.
11
.
Engine
lifting
equipment
shown
installed
acrossengíne
.

CA
UTION-

In
order
to
avoid
the
need
for
front-end
realign-
ment,
donot
unbolt
power
steering
rack
from
sus-
pension
crossmember
.

11
.
Support
suspension
crossmember
from
below
using
appropriate
jacking
equipment
.

12
.
Loosen
nuts
at
top
of
left
and
right
side
engine
mounts
.
Remove
nuts
from
bottom
of
left
and
right
side
engine
mounts
.

13
.
At
left
and
right
sides,
unbolt
control
arm
bushíng
carri-
ers
from
body
.
Disconnect
stabilizer
bar
links
fromcon-
trol
arms
.
Refer
to
Fig
.
3
.

14
.
Remove
bolts
from
left
and
right
sides
of
suspension
crossmember
and
lower
front
axle
as
far
as
possible
.

15
.
Remove
fuelline
clamping
brackets
from
oil
pan
.
On
cars
with
automatic
transmission,
remove
ATF
cooler
line
brackets
from
oil
pan
.

16
.
Remove
oil
pan
screws
.
Lower
and
remove
oil
pan
for-
ward
to
remove
.

CA
UTION-

If
the
oil
pan
does
not
separate
easily
from
the
en-
gine
cylinder
block,
a
few
taps
with
a
rubber
mallet
shouldbreak
it
free
.
Do
notpry
the
oil
pan
loose
.

OIL
PAN

GENERAL
.
........
.
...........
.
.
.
.
.
.
.
120-1



Camshaft
Position
(CMP)
Sensor
....
.
.
.
...
120-6

Disabling
Ignition
System
.
.
.
.
.....
.
.
.
.
.
.
.
120-2



Camshaft
position
(CMP)
sensor,
replacing

Warnings
and
Cautions
.
.
.
.
.
.
.....
.
.
.
.
.
.
.
120-2



(4-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
120-6

Camshaft
position
(CMP)
sensor,
replacing

IGNITION
SYSTEM
DIAGNOSTICS
.
.
.
.
.
.
120-3



(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
120-7
Basic
Troubleshooting
Principles
...
.
.
.
.
.
.
.
120-3



Knock
sensors,
replacing
.
.
...
.
.
.
.
.
.
.
.
.
.
.
.
120-7

Ignition
Firing
Order
.....
.
...
.
.
.
.....
.
.
.
.120-7

IGNITION
SYSTEM
SERVICE
.
.........
.
120-3

Checking
for
Spark
..
.
.
.
.
.
.
.
.
.
.......
.
.
.
120-3

Ignition
coil,
testing
and
replacing

(4-cylinder
engine)
.
.
.
.
.
.
.
.
.
.
.........
.
120-3

Ignition
coil,
testing
and
replacing

(6-cylinder
engine)
.........
.
..........
120-4

Crankshaft
Positionlrpm
Sensor
.......
.
...
120-5

Crankshaft
position/rpm
sensor,
testing
and

replacing
(front
mounted)
.........
.
.
.
.
.
.
120-6

Crankshaft
position/rpm
sensor,replacing

(rear
mounted)
.....
.
.....
.
.....
.
.
.
.
.
.
120-6

GENERAL



Troubleshooting
and
testing
of
the
engine
management

system
should
be
carried
out
using
the
BMW
specialized
ser

This
repair
group
covers
repair
andcomponent
replace-



vice
tester
(scan
tool)
.

ment
information
for
the
ignition
system
.
All
engines
use
a
distributorless
ignition
system
with
indívid-

ual
ignitioncoils
for
each
cylinder
.
There
is
no
distributor
cap

NOTE-



or
ignition
rotor
.
Each
coil
can
be
selectively
controlled
by
the

"
Spark
plug
replacement
is
covered
in
020
Mainte-



engine
control
module
on
a
cylinder-by-cylinder
basis
.
On
later

nance
Program
.



systems,
knock
sensors
are
used
to
monitor
and
control
igni-

"
For
fuel
related
troubleshooting
and
testing,
see
130



tion
knock
(ping)
and
adjusttiming
accordingly
.

Fuel
lnjection
.
Ignition
timing
is
electronically
controlled
and
not
adjust-

All
engines
covered
by
this
manual
use
an
advanced
en-



able
.
The
engine
control
module
(ECM)
usesengine
load,
en-

gine
management
system
.
The
engine
management
system



gine
speed,
coolant
temperature,
and
intake
air
temperature

incorporates
on-board
diagnostics,
fuel
injection,
ignition
and



as
the
basic
inputs
for
timing
control
.
Knock
detection
is
also

other
advanced
engine
control
functions
.



an
input
to
the
control
module,
where
applicable
.

Table
a
.
Engine
Management
System
Variants

Engine
code



1
System

4-cylinder
M42
(1.8
I)



Bosch
DME
Ml
.7
M44
(1
.9
I)



Bosch
DME
M5
.2
(OBD
II)

6-cylinder
M50
1992
(2.5
I)



Bosch
DME
M8
.1
1993-1995
(2
.5
I)



Bosch
DME
M33
.1
M52
1996-1998
(2.8
I)



Siemens
MS
41
.1
(OBD
II)

1998
(2
.5
I)



Siemens
MS
41
.1
(013D
11)
S50US
(3.0
I)



Bosch
DME
M3
.3.1
S52US
(3.2
I)



Siemens
MS
41
.1
(OBD
II)

120
Ignition
System

IGNITION
SYSTEM



120-1

IGNITION
SYSTEM
SCHEMATICS
...
.
.
.
.120-7

TABLES

a
.
Engine
Management
System
Variants
......
120-1

b
.
Ignition
Coil
Resistance
(M42
engine)
......
120-4

c
.
Ignition
Coil
Resistance
(M44
engine)
......
120-4

d
.
Ignition
Coil
Resistance

(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.....
.
..
120-5

NOTE-

All
engines
coveredby
this
manual,
with
theexception

of
the
1992
M50,
incorporate
knocksensors
as
part
of

the
engine
management
system
.

The
initial
ignition
point
is
determined
by
the
crankshaft
po-

sition/rpm
sensor
during
cranking
.
Once
the
engine
is
run-

ning,
timing
is
continually
adjusted
based
on
operating

conditions
.
A
characteristic
ignition
map
is
shown
in
Fig
.
1
.
A

map
similar
to
the
one
shown
is
digitally
stored
in
the
engine

control
module
.

GENERAL

120-2



IGNITION
SYSTEM

Fig
.1
.



Ignition
characteristic
map
.

Disabling
Ignition
System

WARNING
-

The
ignition
system
is
a
high-energy
system
operat-
ing
in
a
dangerous
voltage
range
that
couldprove
to
be
fatal
if
exposed
terminals
or
live
parts
are
con-
tacted
.
Use
extreme
caution
when
working
on
a
car
with
the
ignition
on
or
the
engine
running
.

The
ignition
system
operates
in
a
lethal
voltage
range
and
should
therefore
be
disabied
any
time
senrice
or
repair
work
is
being
doneon
the
engine
that
requires
the
ignition
to
be
switched
on
.

The
engine
management
system
can
be
disabled
byremov-
ingthe
main
relay
.
The
relay
is
located
in
the
power
distribution
box
in
the
left
rear
of
the
engine
compartment
.
See
Fig
.
2
.

0013134
Fig
.
2
.



Maínsystem
relay
(arrow)
in
power
distribution
box
(left
rear
of
engine
compartment)
.

GENERAL

WARNING
-

"
Do
not
touch
or
disconnect
any
of
the
high
ten-
sion
cables
at
the
cotls
orspark
plugs
while
the
engine
ts
running
orbeingcranked
by
the
starter
.
Fatalvoltages
are
present
.

"
Before
operating
the
starter
without
starting
the
engine
(for
example
when
making
a
compression
test)
always
disable
the
ignition
.

CAUTION-

"
Prior
to
disconnecting
the
battery,
read
the
bat-tery
disconnection
cautions
gtven
at
the
front
of
thts
manual
on
page
viti
.

"
Do
not
attempt
to
disable
the
ignition
by
either
re-
moving
the
cotl
from
the
spark
plugs
(6-cylinder
engines)
or
disconnecting
the
coll
wires
from
the
plugs
(4-cylinder
engines)
.

"
Connect
or
disconnect
ignition
system
wires,
multiple
connectors,
and
ignition
test
equipment
leads
only
while
the
ignitionis
off
.
Switch
multtm-
eter
functions
or
measurement
ranges
onty
with
the
test
probes
disconnected
.

"
Do
not
disconnect
the
battery
while
the
engine
ts
running
.

"
Many
of
the
tests
of
ignition
system
components
require
the
use
of
high-impedance
test
equip-
ment
to
prevent
damage
to
the
electrical
compo-
nents
.
A
high
impedance
digital
multimeter
should
be
used
for
all
voltage
and
resistance
tests
.
AnLED
test
light
shouldbe
used
in
place
of
an
incandescent-type
test
lamp
.

"In
general,
make
test
connections
only
as
speci-fied
by
BMW,
as
described
inthis
manual,
or
as
described
by
the
instrumenta
manufacturer
.

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

120-
4



IGNITION
SYSTEM

2
.
Check
for
battery
voltage
o
cofs
.
If
voltage
is
not



Table
b
.
Ignition
Coil
Resistance

present,
check
wire
between
terminal
15
and
ignition



(M42
Engine)
switch
.
See
Electrical
Wiring
Diagrams
.

"
On
M42
engine,
connect
digital
multimeter
between
ter-

minal
15(+)
in
each
harness
connector
and
ground
.
See

Fig
.
4
.

"
On
M44
engine,
connect
voltmeter
between
terminal
2

(15+)
in
connector
and
ground
.
Turn
ignition
on
and

check
for
voltage
.
See
Fig
.
5
.

3
.
Turn
ignition
off
.

0
4a15

Fig
.
4
.



Ignition
coil
harness
connector
terminal
identification
for
M42

engine
.

Fig
.
5
.



Ignition
coil
harness
connector
terminal
identification
for
M44
engine
.

CAUTION-

The
wiring
to
the
coil(via
the
ignition
switch
15+)
is
not
fuse
protected
.
Use
care
when
testing
thiscircuit
.

4
.
Use
a
digital
multimeter
totest
coil
primary
resistance
.

"
On
M42
engine,
use
Table
b
asa
guide
to
check
coil

resistance
.
Make
checks
at
each
harness
connector
.

"
On
M44
engine,
use
Table,c
as
a
guide
to
check
coil
primary
resistance
.

5
.
Inspect
coil
housing
for
hairline
cracks
or
leaking
cast-
ing
material
.
See
Fig
.
7
.
A
leaky
ignition
coil
may
indi-



11502

cate
a
faulty
ECM
(engine
control
module)
.
Check
the
ECM
before
installing
a
new
coil
.



Fig
.
6
.



Ignition
coil
harnessconnector
terminal
identification
for
6-
cylinder
engine
.

IGNITION
SYSTEM
SERVICE

11502

Terminals
Resistance
(refer
to
Fig
.
4
.)

Coil
primary



1
(-)
and
15
(+)



10
.4-0
.8
ohms

Coil
secondary



N
.A
.



N
.A
.

Table
c
.
Ignition
Coil
Resistance

(M44
Engine)

Terminais
Resistance
(referto
Fig
.
5
.)

Coil
#1
primary



1
(-)
and
2
(+)



0
.4-0
.8
ohms

Coil
#2
primary



6
(-)
and2
(+)



0
.4-0
.8
ohms

Coil
#3
primary



7
(-)
and
2
(+)



0
.4-0
.8
ohms

Coil
#4
primary



5
(-)
and2
(+)



0
.4-0
.8
ohms

Coil
secondary



N
.A
.



N
.A
.

NOTE-

If
a
single
coilís
faulty
on
M44
engines,
the
complete
coil
pack
will
have
to
be
replaced
.

Ignition
coil,
testing
and
replacing

(6-cylinder
engine)

CAUTION-

Use
a
digital
multimeter
for
the
following
tests
.

1.
Remove
plastic
enginecovers
from
top
of
engine
by

prying
off
nut
covers
and
removingcover
mounting

nuts
.
See
113
Cylinder
HeadRemoval
and
Installa-

tion
.

2
.
Disconnect
harnessconnectorfromcof
.
Connect
mul-
timeter
between
terminal
15
(+)
in
connector
and

ground
.
See
Fig
.
6
.

3
.
Turn
ignition
on
and
check
for
batteryvoltage
.

"
If
batteryvoltage
is
not
present,
check
wire
between

terminal
15
and
ignition
switch
.
See
Electrical
Wiring

Diagrams
.

"mozo