1998 BMW 328i 100 engine-general

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

Camshaft
position
(CMP)
sensor,

replacing
(6-cylinder
engine)

1
.
Remove
plastic
cover
from
above
fuel
injectors
.

2
.
Disconnect
harness
connector
from
VANOS
solenoid

and
unscrew
solenoid
from
VANOS
control
unit
.
Re-



"
Clean
contactsurface
on
engine
block
before
fnstall

move
oil
supply
line
from
VANOS
control
unit
.
See
117



ing
knock
sensors
.

Camshaft
Timing
Chain
.

3
.
Remove
camshaft
position
(CMP)
sensor
from
left
frontof

cylinder
head,
next
to
top
of
oil
filter
housing
.



"
Knock
sensor
to
cylinder
block
....
20
Nm
(15
ft
.
lbs
.)

4
.
Disconnect
CMP
sensor
harnessfrom
under
intake

manifold
.

5
.
Installation
is
reverse
of
removal
.
Use
a
new
O-ring

when
installing
sensor
.
Be
sure
wiring
is
rerouted
in

same
orientation
.

Tightening
Torques

"
CMP
sensor
to
cylinder
head
....
.
.
..
5
Nm
(3
.5
ft-Ib)

"
VANOS
oil
supply
pipe
to

VANOS
control
unit
...........
.
..
32
Nm
(24
ft-Ib)

"
VANOS
solenoid
to
VANOS

control
unit
...
.
.................
30
Nm
(22
ft-Ib)

Knock
sensors,
replacing

Knock
sensors
are
usedon
engines
with
Bosch
DME
M1
.7,

Bosch
DME
M3
.3
.1,
Bosch
DME
M5
.2,
and
Siemens
MS
41
.1

engine
management
systems
.
The
knocksensors
are
bolted
to
the
left
sideof
the
cylinder
block
and
monitor
the
combus-

tion
chamber
for
engine-damaging
knock
.
If
engine
knock
is

detected,
the
ignition
point
is
retarded
accordingly
via
the
en-

gine
control
module
.

CA
UTION-

"
Label
knock
sensorharness
connectors
before

disconnecting
them
.
The
connectors
must
not
be

interchanged
.
Engine
damage
may
result
if
the
sensors
are
monitoring
the
wrong
cytinders
.

"
Note
the
installed
angle
of
the
knock
sensoron
the

block
before
removing
it
.
Reinstall
the
sensor
in

the
same
position
.
Be
sure
to
usea
torque
wrench

when
tightening
the
sensormounting
bola

NOTE
-

"
On
M52
engines,
a
single
harness
connects
the
twosensors
to
the
main
harness
connector
.
The
shorter
cable
lead
fs
for
the
knock
sensor
for
cytinders
4,
5,
and
6
.

Tightening
Torque

IGNITION
SYSTEM



120-
7

0012730

Fig
.
12
.
Knock
sensor
mounting
bolt
on
front
left
side
of
cylinder

block
.

NOTE-

Knock
sensor
function
Is
monitoredby
the
On-Board
Diagnostic
system
.
If
a
knock
sensor
is
detected
to
be
faulty,
an
appropriatediagnostic
trouble
code
(DTC)
may
be
stored
in
memory
.
See
100
Engine-General
for
information
on
retrieving
DTCs
.

On
6-cylinder
engines,
the
knock
sensors
are
accessible
af-
ter
removing
the
intake
manifold
.
On
4-cylinder
engines,
the

upper
section
of
the
intake
manifold
should
be
removed
to
ac-

cess
the
sensors
.
See
Fig
.
12
.
NOTE-

Intakemanifold
removal
and
installation
procedures
are



"
Cylinder
no
.
1is
at
the
front
of
the
engine
.

covered
in
113
Cylinder
HeadRemoval
and
Installation
.

Ignition
Firing
Order

Ignition
Firing
Order

"
4-cylinder
engines
.....
..
...
.
..........
.1-3-4-2

"
6-cylinder
engines
...........
..
.
.
..
..
1-5-3-6-2-4

IGNITION
SYSTEM
SCHEMATICS

Fig
.
13
through
Fig
.
17
show
ignition
system
schematics

usedon
the
enginescoveredby
this
manual
.

IGNITION
SYSTEM
SCHEMATICS

FUEL
INJECTION



130-
3

Fuel
metering
.
The
ECM
meters
fuel
bychanging
the



The
engine
management
system
compensates
automatical-
opening
time
(pulsewidth)
of
the
fuel
injectors
.
To
ensure
that



ly
for
changes
in
the
engine
due
to
age,
minor
wear
or
small
injector
pulsewídth
is
the
only
factor
that
determines
fuel
me-



problems,
such
as
a
disconnected
vacuum
hose
.
Asa
result,
tering,fuel
pressure
is
maintained
bya
fuel
pressure
regula-



idle
speed
and
mixture
do
not
need
lo
be
adjustedas
partof
tor
.
The
injectors
are
mounted
lo
a
common
fuel
supply
called



routine
maintenance
.
the
fuel
rail
.

The
ECM
monitors
engine
speed
to
determine
the
duration



NOTE-

ofinjector
openings
.
Other
signals
to
the
ECM
help
determine



Poordriveabilitymaybe
encountered
when
the
batteryis

injector
pulse
time
for
different
operating
conditions
.
A
tem-



disconnected
and
reconnected
.
when
the
battery
is
dis-
connected,
the
adaptive
memory
is
lost
The
system
will
perature
sensor
signals
engine
temperature
for
mixture
adap-



readaptafterabout
ten
minutes
of
drfving
.
tion
.
A
throttle
position
sensor
signals
throttle
position
.
The
exhaust
oxygen
sensor(s)
signal
information
about
combus-
tion
efficiency
for
control
of
the
air-fuel
mixture
.
1992
to
1995



DISA
(Dual
Resonance
Intake
System)
engines
are
equipped
with
a
single
sensor
.
1996
and
later
(OBD
II)
engines
are
equipped
with
an
oxygen
sensor
before



TheE36
4-cylinder
engine
is
equipped
with
a
dual
intake
andone
after
each
catalytic
converter
.
Forexample,the
M52



runner
system,
termed
DISA
.
DISA
offers
the
advantages
of
engine
is
equipped
withfour
oxygen
sensors
.



both
short
and
long
intake
pipes
.
Long
intake
runners
are
most
useful
at
low
to
medium
engine
rpm
for
producing
good
Idle
speed
control
.
ldle
speed
is
electronically
controlled



torque
characteristics
.
Short
intake
runners
produce
hígherviathe
idle
speed
control
valve,
which
maintains
idle
speed
by



horsepower
at
hígher
engine
speeds
.
bypassing
varying
amounts
of
air
around
theclosed
throttle
valve
.
Idle
speed
is
not
adjustable
.



NOTE-

Knock
(detonation)
control
.
Knock
sensors
monitor
and



The
term
DISA
comes
from
the
German
words
Differen-

control
ignition
knock
through
the
ECM
.
The
knock
sensors



zierte
Sauganlage,
and
can
roughlybe
translated
as
"dif-
fering
intake
manifold
configuration
."
See
100
Engine-
function
like
microphones
and
are
able
to
convert
mechanical



General
foradditional
information
on
DISA
operation
.
vibration
(knock)
into
electrical
signals
.
The
ECM
is
pro-

grammed
to
react
to
frequencies
that
are
characteristic
of
en-



Manifold
construction
:
The
intake
manifold
is
a
two-piece
gine
knock
and
adapt
the
ignition
timing
point
accordingly
.



metal
construction,
with
a
pair
of
runners
in
thetop
section
See120
Ignition
System
for
further
details
.



and
four
runners
in
the
lower
section
.
A
butterfly
valve
is
in-
stalled
in
the
lower
section,
enabling
the
DISA
solenoid
toiso-

NOTE-



late
one
pair
of
runners
from
the
other
pair
.
See
Fig
.
2
.

The
1992
M50
engine
is
not
equipped
with
knock
sen-



Operation
.
With
the
DISA
butterfly
valve
closed,
the
pipes
sors
.
All
other
engines
are
equipped
with
two
knock



in
thetop
half
of
the
manifold
act
together
with
the
ram
air
sensors
.



pipes
in
the
lower
halfto
producea
single,
long
air
intake
pipe
for
each
cylinder
.
See
Fig
.
3
.
The
column
of
aír
oscíllating
in

Basic
Engine
Settings



this
combined
pipe
significantly
increases
engine
torque
in
the

medium
rpm
range
.

Idle
speed,
idle
mixture
(%CO),
and
ignition
timing
arenot

adjustable
.
The
adaptive
engine
management
system
is
de-

signed
to
automatically
compensate
for
changes
in
engine
op-

eratingconditions,
although
the
adaptive
range
is
limited
.
Once

these
limits
are
exceeded,
driveability
problems
usually
be-

come
noticeable
.

Above
approximately
4,800
rpm,
the
butterfly
valve
between
the
intake
air
pipes
for
the
two
cylinder
groups
is
opened
.
The
shorter
pipes
in
the
lower
manifold
section
now
become
the

main
suppliers
of
ram
air
to
the
cylinders,yielding
greater
pow-

er
at
the
upper
end
of
the
engine
rpm
range
.
See
Fig
.
4
.

Control
components
.
The
DISA
butterfly
valve
is
actuated

NOTE-



electro-pneumatically
via
the
engine
control
module
(ECM)
.

lf
the
system
adaptive
limits
are
exceeded,
the
Check



The
valve
begins
to
open
as
engine
speed
rises
aboye
4,840

Engine
light
will
most
likely
come
on,
indicating
an



rpmand
closes
below
4,760
rpm
.
The
action
of
the
valve
is
de-
emissions-
related
fault
For
Check
Engine
light
diag-



liberately
delayed
to
prevent
it
from
opening
and
closing
repeat-
nostics,
see100
Engine-General
.



edly
within
a
short
time
.

GENERAL

130-
4



FUEL
INJECTION

Main
Relay

Fig
.
2
.



DISA
system
components
.
DISA
is
controlled
via
theengine
control
module
(ECM)
.

Fig
.
3
.



DISA
manifold
runners
with
butterfly
valve
closed
for
lowrpm-
high
torque
operation
.

yje
q

GENERAL

high
power
operation
.

0012734

Fig
.
4
.



DISA
manifold
runners
with
butterfly
valve
open
for
high
rpm-

On-Board
Diagnostics
(OBD)

and
Fault
Diagnosis

Poor
driveability
may
have
a
variety
of
causes
.
The
fault

may
He
withthe
ignition
system,
the
fuel
system,
parts
ofthe

emission
control
system,
ora
combination
of
thethree
.
Be-

cause
of
these
interrelated
functions
and
their
effects
on
each
other,
it
is
often
difficult
to
know
where
to
begin
looking
for

problems
.

For
this
reason,
effective
troubleshooting
should
always
be-

gin
with
an
interrogation
of
the
On-Board
Diagnostic
(01313)

system
.

The
OBD
system
detects
certain
emissions-related
engine

management
malfunctions
.
When
faults
are
detected,the

OBD
system
storesa
Diagnostic
Trouble
Code
(DTC)
in
the

system
ECM
.
In
addition,
the
Check
Engine
warning
light
will

come
on
if
an
emissions-related
fault
is
detected
.

Two
generations
of
OBD
are
used
on
thecars
covered
by
this
manual
.
See
100
Engine-General
for
OBD
I
information

and
fault
codes
.

On-Board
Diagnostics

"
1992-1995models
....
.
...
...
.
...
......
OBD
I

"
1996-1998models
....
.
..
.
.
.
..
...
......
OBD
II

630-2



EXTERIOR
LIGHTING

Headlight
assembly,

removing
and
installing

CAUTION-

Followingheadlight
assembly
work
headlight

beam
aim
must
be
adjusted
using
special
equip-
ment
.

1
.
Left
side
:
Remove
air
filter
housing,
air
intake
duct,
and

air
mass
meter
.
See
100
Engine-General
.

2
.
Disconnect
harness
connectors
from
headlight
bulbs
.

3
.
Remove
front
turn
signal
.
See
Front
turn
signal
as-

sembly,
removingand
installing
later
in
this
repair

group
.

4
.
Remove
radiator
cover
.
See
Fig
.
2
.

5
.
Using
a
wrench,
brace
adjusting
nut
at
top
center
of
headlight
.
Remove
three
screws
at
top
of
assembly
.

See
Fig
.
3
.

Fig
.
3
.



Brace
headlightadjustingnut
as
shown
and
remove
top
screws
(arrows)
.

FRONT
LIGHTING

0012568
0012569

6
.
Remove
two
screwson
bottom
of
assembly
.
See
Fig
.

4
.

0012567a

Fig
.
4
.



Headlight
bottom
retaining
screws
(arrows)
.
Screws
mount
in
threaded
expanding
rivets
which
act
as
headlightheight

adjusters
.

7
.
Remove
headlight
assembly
from
front
.

8
.
On
installation,
tighten
lower
screws
first
while
holding

expanding
rivets
with
a
wrench
.
There
should
be
a
2
.5

mm
gap
between
bottom
oflens
and
front
panel
.
Use

adjusting
nut
to
raise
or
lower
headlight
unit
.
See
Fig
.
5
.

0012681

Fig
.
5
.



Measure
gap
A
(2.5
mm)
between
bottom
of
headlight
as-
sembly
and
front
panel
.

9
.
Clearance
between
hood
and
headlight
cover
should
be
1
.5
mm
.
Adjust
by
turning
upper
headlight
adjustinq
nuts,
then
tighten
down
center
screw
.
See
Fig
.
6
.

WARNING

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

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

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

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

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

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

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

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

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

headlights/foglights
ELE-180

INDEX
3

Electrical
wiring
diagrams
(cont
.)

heated
seats
ELE-245

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

power
sunroof
ELE-248

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