1997 BMW 318i idle air

020-6



MAINTENANCE
PROGRAM

Group
310/330

Table
c
.
Inspection
II
Service

a
d

d



a



a>



0
d

a



r



.c



mm
L



m
y



L
E

ó
3
E
ó

Maintenance
ítem



l
o-



z



~



c

Engine
compartment
maintenance

Inspect
V-belt
/Poly-ribbeddrive
condition
.
Check
V-belt
tension,
if
applicable
.

Lubricate
throttle
linkage
.

Replace
air
filter
.

Change
oil
and
oil
filter
.

Replacespark
plugs
.
Repair
Group
120

Check
brake/clutch
fluid
leve¡
.

Check
battery
acid
leve¡
and
correct
asnecessary
.
Repair
Group
121

Check
engine
coolant
leve¡
and
anti-freeze
protection
and
add
asnecessary
.
Inspect
for
cooling
system
leaks
.
Repair
Group
170

Under
car
maintenance

Change
automatic
transmission
fluid
.
Repair
Group
240

Change
manual
transmission
oil
.
Repair
Group
230

Check
clutch
plate
for
wear
.
Repair
Group
210

Check
drive
axle
boots
for
leaks
.
Repair
Group
330

Change
final
drive
fluid
(1995
and
later
models
:
change
synthetic
oil
every
2nd
Inspection
II)
.

Replace
fuel
filter
.

Check
fuel
tank,
fuel
lines,
and
af
connections
for
leaks
.

Inspect
exhaust
system
.
Repair
Group
180

Check
steering
gear
and
steering
¡inkages
.
Check
power
steering
system
for
leaks
.
Check
fluidleve¡
.
Repair
Group
320

Inspect
brake
system
for
damaged
hoses
and
lines,
leaks
or
damage
.
Remove
calipers
and
check
brake
pad
wear
.
Check
brake
rotors
for
scoring
damage
.
Repair
Group
340

Check
parking
brake
operation,
adjust
cable
if
necessary
.
Check
thickness
of
parking
brake
lin-
ings
.
Repair
Group
340

Inspect
front
and
rear
suspension,
including
front
and
rear
wheel
bearings,
for
play
.
Repair

Inspect
wheels
and
tires,
including
spare,
check
tire
pressure
and
condition
.

Body
and
Interior
Maintenance

Lubricate
door
hinges
and
hood
latch,
hood
hinges
.

Check
headlight
and
driving
light
aiming
and
adjust
asnecessary
.

Check
operation
of
headlights,
parking
lights,
back-up
lights,
licenseplate
lights,
interior
lights,
glove
box
light,
engine
compartment
light,
trunk
light,
instrument
panel
lights,
turn
signals,
emer-gency
flashers,
stop
lights,
horns,
headlight
flasher
anddimmer
switch
.

Check
active
check
control
panel
forfauits
(where
applicable)
.
6
Electrical
System

MAINTENANCE
TABLES

Continued
on
next
page

100-4
ENGINE-GENERAL

'



TEMP

PRECAT



POST
CAT



OXYGENSENSOR
HEATING

#
.
THROTTLE
POSITION



FUEL
INJECTOR
CONTROL
(SEQUENTIAL)

OPERATING
POWER



00

CAMSHAFT
POSITION
SENSOR

ECM



I
MAIN
GROUND

RELAY



J_



-



AC
COMPRESSOR
RELAY
CONTROL

TERMINAL
15

MEMORY
POWER
FUEL
PUMP
RELAY
CONTROL
AUX
GROUND
P

CRANKSHAFT
POSITION
dESENSOR

INTAKE
AIR

ENGINE
COOLANT
TEMP

FUEL
TANK
PRESSURE
SENSOR

S-EML
S-MSR

ASC
S-ASC

VEHICLE
SPEED

LOW
FUEL
LEVEL

A/C
SWITCH
ON
(AC)
E36
IHKA
COMPRESSOR"ON"

SIGNAL
(KO)

INDIVIDUAL
SERIAL
NUMBER

MS41
.1

SECONDARY
AIR
1NJECTION
AIR
PUMP®
RELAY
CONTROL

IDLE
CONTROL
VALVE



'M

FUEL
INJECTION
(TI)

ENGINE
SPEED
(TD)

Fig
.
5
.



Siemens
MS
41
.1
OBD
II
engine
management
systemusedon
1996
and
later
M52
engines
.

GENERAL

IGNITION
COILS
CONTROL

L
r"Q
if~
CIYVFIYC



CHE
AMP
CONTROL
ENGINE

THROTTLE
POSITION

6

ECM
RELAY
CONTROL

ASC

THROTTLE
..
:
.
.
..
-11



1Q\\\
POTENTIOMETER
POWER

CAN



TCM
II



SCAN
(DES
;
ER

DIAGNOSIS

OBD
II
I
II

GENERIC
SCANTOOL



0012596

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

Graphic
representation
of
flashing
Check
Engine
light
fault
code
:
1221

-
;
5
Seconds
.
~-



2
.5;-

Fault
code
and
meaning



Corrective
action

Code
1286
:
Knock
control
test
pulse
(DME
3
.3
.1
only)



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

Code
1000
(light
remains
off)
:



End
of
fault
code
output-all
fault
codes
have
been
displayed
.
No

~
corrective
action
necessary
.
Repeat
test
if
necessary

Code
1444
:



No
more
faults
.
No
corrective
action
necessary
.
This
code
must
be
present
lo
erase
fault
memory

Basic
Requirements



Preventive
Maintenance

The
following
list
contains
basic
checks
that
should
be
made
when
experiencing
driveability
problems
.

1
.
Check
intake
(induction)
system
for
leaks
.
Check
for

cracked,
loose,
or
disconnected
hoses
and
duct
work
.

Check
that
all
hose
clamps
are
tight
.

NOTE-

An
air
leak
allows
unmeasured
airto
enter
the
engine,
offen
resulting
in
an
in
overly
lean
fuel
mixture
and
causing
driveability
problems
which
will
cause
the
Check
Engine
light
to
come
on
.

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

(1992-1995
models
only)

7
-
1
--------------
Check
Engine
light
on

ENGINE-GENERAL
100-
1
1

Check
Engine
light
off

The
condition
of
the
fuel,
ignition
and
emission
controlsys-

tem
components
has
a
directeffect
onengineperformance

and
driveability
.
BMW
specifies
maintenance
of
certain
parts

at
regular
intervals
lo
keep
the
engine
in
proper
tune
.
Extend-
ing
maintenance
intervals
beyond
the
time
or
mileagerecom-
mended
bythe
manufacturer
can
adversely
affect
the
way
the
engine
runs
.
When
troubleshooting
driveability
problems,
a
good
starting
point
is
to
perform
a
major
engine
service,par-

ticularly
if
one
is
overdue
.
For
maintenance
schedules,
major
engine
service
and
other
driveability-related
maintenance

procedures,
see020
Maintenance
Program
.

Basic
Engine
Settings

2
.
Check
that
the
battery
isin
good
condition
.
Check
that

the
cables
are
tight
and
free
of
corrosion
at
both
ends
.



Idle
speed,
idle
mixture
(%CO),
and
ignition
timing
are
not

Check
that
all
related
ground
points
are
firmly
connect-



adjustable
.
The
adaptive
engine
management
system
is
de-

ed
and
in
good
condition
.
Check
al¡
harness
connectors



signed
lo
automatically
compensate
for
changes
in
engine
op-

for
damage
and
corrosion
.



erating
conditions,
although
the
adaptive
range
is
limited
.

Once
these
limits
are
exceeded,
driveability
problems
usually

3
.
Check
for
prwer
and
ground
at
the
Engine
Control



become
noticeable
.

Module
(ECM)
.
Check
the
main
grounds
for
the
ECM
.

See130
Fuel
Injection
.



NOTE-

If
the
DME
adaptive
limits
are
exceeded,
the
Check
En-
4
.
Check
the
fuses
.
Check
for
sufficient
fuel
in
the
tank
.
If



gine
light
will
come
on,
indicating
an
emission
related
the
engine
ranout
of
fuel,
it
will
take
a
little
time
to
re-



fault
.
See
130
Fuel
Injection,
store
fuel
pressure
.
See
160
Fuel
Tank
and
Fuel

Pump
.
Oxygen
Sensors

5
.
Check
for
spark
at
the
spark
plugs
.
If
the
tachometer

needle
bounces
while
the
engine
is
crankedby
the



A
high
oxygen
level
in
the
engine
exhaust
indicates
a
lean

starter
then
the
ignition
system
is
probably
working
cor-



air-fuel
mixture
and
a
low
oxygen
level
indicates
a
rich
mix

rectly
.
See
120
Ignition
System
.



ture
.
The
oxygen
sensor,
shown
in
Fig
.
10,
measures
the
oxy-

gen
content
in
the
exhaust
gasand
generates
a
variable

6
.
Check
for
any
faults
through
the
On-Board
Diagnostics



voltage
signal
.
Using
that
feedback
signal
asan
input,
the

system
.
See
On-Board
Diagnostics
(OBD)
.



DME
control
module
fine
tunes
the
air-fuel
mixture
.

DRIVEABILITY
TROUBLESHOOTING

100-
1
2
ENGINE-GENERAL

NOTE-

The
oxygen
sensor
signal
is
ignored
until
the
engine
reachesa
specified
minimum
temperature
.
Therefore,



The
primary
input
usedby
the
fuel
injection
system
to
deter-

when
troubleshooting
cold
engine
driveability
prob-



mine
how
much
fuel
should
be
delivered
is
the
signal
from
the

lems,
the
oxygensensor
canbe
ruled
out
asa
possible



mass
air
flow
sensor
in
the
intake
air
ductwork
.

cause
.

As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to

changing
conditions
deteriorates,
and
it
may
eventually
cease

to
produce
any
signal
at
all
.
To
check
the
operation
of
the
oxy-

gen
sensor,
see
130
Fuel
Injection
:

NOTE-

On
1996
and
latercars,
OBD
11
enhanced
emission
standards
require
the
engine
control
module
(ECM)
to
monitor
the
oxygen
content
in
the
exhaust
both
before
and
after
the
catalytic
converter
.
Thisallows
for
tighter
control
of
the
tail
pipe
emissions
and
also
allowsthe
ECM
to
diagnose
converter
problems
.
If
the
DME
de-
tects
that
catalytic
converter
or
oxygensensor
efficien-
cyhas
degraded
pasta
certain
pre-programmed
limit,
it
will
turn
on
the
Check
Engine
light,
and
store
a
diag-
nostic
trouble
code
(DTC)
in
the
ECM
.

DRIVEABILITY
TROUBLESHOOTING

Catalytic

B9506

Air
Flow
Measurement
and
Vacuum
Leaks

Because
proper
fuel
metering
depends
on
accurate
mea-

surement
of
the
incoming
air,
any
unmeasured
air
that
enters

the
engine
downstream
of
the
mass
air
flow
sensor
will
cause

a
lean
air-fuel
mixture
and
possibly
affectdriveability
.

NOTE-

Fig
.
10
.
Regulating
oxygen
sensor
measures
oxygen
content
of
ex-



gattery
Voltage
hausY
gas
as
indicator
of
.¡_fi
.1
ratio
and
"-k,
.

E-
effi-
ciency
.
Monitoríng
oxygen
sensor
(not
shown)
monitors

If
a
large
air
leak
is
causing
driveability
problems,
the
Check
Engine
light
will
usually
be
illuminated
and
a
fault
will
be
stored
in
the
fault
code
memory
.
See
On
Board
Diagnostics
(OBD)
.

There
are
many
places
for
unmeasured
air
to
enter
theen-

gine
.
First,
inspect
all
hoses,
fittings,
ducts,
seals,
and
gaskets

in
the
intake
air
tract
for
cracks
or
looseness
.
It
may
be
neces-

sary
to
remove
parts
that
cannot
be
fully
checked
in
their
in-

stalled
positions
.
Also
make
sure
all
of
the
intake
manifold
and

throttle
body
mounting
nuts
are
tight
.

In
addition
to
air
leaks,
air
restrictions
can
also
cause
drive-

ability
problems
.
Remove
the
air
filter
and
hold
it
up
to
a
strong

light
source
.
If
the
filter
does
not
pass
light,
it
is
restricted
and

should
be
replaced
.
Also,
remove
the
intake
air
ductwork
and

check
for
oily
deposits
at
the
throttle
plate
.
Buildup
in
this
area

can
cause
an
erratic
idle
.
Clean
away
any
deposits
using
a

cloth
wetted
withcarburetor
cleaner
and
reinstall
the
ductwork
.

CAUTION-

Do
not
spray
carburetor
cleaner
directly
in
the
throt-
tle
anea
.
Spraying
cleaner
may
force
it
into
the
throt-
tle
position
switch
or
sensor
and
cause
damage
.

catalytic
converter
operation
.



All
of
the
electrical
components
in
the
fuelinjection
and
igni-
tion
systems
require
a
minimum
voltage
to
operate
properly
.

When
troubleshooting
engine
driveability
problems,
one
of
Replacement
of
oxygensensors
at
the
specified
intenrals
en-



the
first
checks
should
be
to
make
sure
the
battery
is
fully
sures
that
the
engine
and
emission
control
system
wili
continue



charged
and
capable
of
delivering
allits
power
to
the
electricalto
operate
as
designed
.
As
the
oxygen
sensor
ages,
its
ability
to



system
.
react
quickly
to
changing
conditions
deteriorates,
and
it
may
eventually
cease
to
produceany
signal
at
all
.



To
make
a
quick
check
of
battery
charge,
measure
the
volt-
age
across
the
battery
terminals
with
all
cables
attached
and
As
the
oxygen
sensor
ages,
its
ability
to
react
quickly
to



the
ignition
off
.
A
fully
charged
battery
will
measure
12
.6
volts
changing
conditions
deteriorates,
and
it
may
eventually
cease



or
slightly
more,
compared
to
12
.15
volts
for
a
battery
with
a
to
produce
any
signal
at
all
.
To
check
theoperation
of
the
oxy-



25%
charge
.
gen
sensor,
see130
Fuel
Injection
.

Even
a
fully
charged
battery
cannot
deliver
power
unless
it

is
properly
connected
to
the
electrical
system
.
Check
the
bat-
tery
terminals
for
corrosion
and
loosecableconnections
.
If
the
battery
does
not
maintain
the
proper
voltage,
the
charging
system
may
be
atfault
.
See
121
Battery,
Starter,
Alternator
.

100-
1
4
ENGINE-GENERAL

0013131

Fig
.
13
.
Main
chassis
ground
(arrow)
inleft
front
of
engine
compart-
ment
.

Fuel
Supply

For
the
engine
tostart
and
run
properly,
the
injection
sys-

tem
must
deliver
fuel
in
precise
proportion
to
the
amount
of
air

entering
the
engine
.
Todo
this,
the
injection
system
requires

an
unrestricted
supply
of
fuel
from
the
fuel
pump
.

If
the
fuel
pump
is
not
working,
the
engine
will
notrun
.
If
the
fuel
filter
or
a
fuel
line
is
restricted,
the
engine
may
run
poorly
.
If
the
restriction
is
severe
enough
the
engine
will
not
start
.
lf

fuel
delivery
problemsare
suspected,
perform
the
tests
de-

scribed
in
160
Fuel
Tank
and
Fuel
Pump
.

The
fuel
pressure
created
by
the
fuel
pump
is
controlled
by
a
pressure
regulator
thatreturns
excess
fuelto
the
tank
.
Any
change
in
fuel
pressure
will
cause
a
change
in
the
base
air-fuel

mixture
delivered
to
the
engine
.
If
the
fuel
pressure
is
too
low,
the

base
air-fuel
mixture
will
be
lean
.
lf
the
fuel
pressure
is
too
high,
the
base
mixture
will
be
rich
.
Fuel
pressure
tests
aredescribed
in
160
Fuel
Tank
and
Fuel
Pump
and130
Fuel
Injection
.

NOTE-

Fuel
pressure
tests
require
a
pressure
gauge
.
If
thistoolís
not
avaílable,
the
tests
can
be
performed
byan
authorized
BMW
dealer
or
other
qualified
shop
.

DRIVEABILITY
TROUBLESHOOTING

Properly
operating
fuel
injectors
play
amajor
role
in
fuel
de-

livery
.
The
DMEECM
switches
the
injectors
on
and
off
at
the

negative
(-)
or
ground
side
of
the
connectors
.
Posítíve
(+)
bat-

tery
voltage
is
always
present
at
the
connectors
when
theen-

gine
is
running
.
An
injector
that
fails
or
loses
power
will
not

open,
creating
a
lean
air-fuel
mixture
and
causing
the
engine
to

run
poorly
when
coldor
stumble
on
acceleration
.
An
injector

that
shorts
to
ground
will
remain
open
constantly
when
the
en-

gine
is
running,
creating
a
richair-fuel
mixture
that
can
dilute

engine
oil,
foul
the
spark
plugs,
cause
a
rough
idle,
and
damage

the
catalytic
converter
.

Table
e
lists
additional
symptoms
of
common
engine
drive-

ability
problems,
their
probable
causes,
and
the
suggested

corrective
actions
.
The
entries
in
boldtype
in
the
corrective

action
column
indicate
the
repair
groups
where
applicable
test

and
repair
procedures
can
befound
.

NOTE-

Most
of
the
symptoms
fisted
in
Table
e
will
also
cause
the
Check
Engine
light
to
come
on
.
If
the
light
is
on,

check
for
any
stored
faults
as
the
first
step
ín
trouble-
shooting
driveability
complaints
.

al
Icld

Table
e
.
Engine
Driveability
Troubleshooting

c
l



1



I



f



I



I
Oxygen
sensor
faulty



Test
oxygen
sensor
.

ENGINE-GENERAL
100-
1
5

SYMPTOMS

a
.
Engine
fafs
tostart

b
.
Engine
startsbut
stops
immediately

c
.
Erratic
engine
idle

d
.
Poor
engine
responseon
acceleration

e
.
Erratic
engine
operation
in
al¡
speed
ranges

f
.
Excessive
fuel
consumption
g
.
Poor
enginepower,
fails
to
rev
up
h
.
CO
content
toolow

i.
CO
content
too
high

CAUSES



CORRECTIVE
ACTION

a



Fuel
pump
faulty



Test
fuel
pump
.
Repair
Group
160

a



e



Ignition
system
faulty



Test
ignition
system
.
Repair
Group
120
a



Main
relay
or
fuel
pump
relay
faulty



Test
main
relay
.
Repair
Group
130
a



Crankshaft/rpm
position
sensor
faulty



Test
crankshaft/rpm
sensor
.
120
b



c



h



i



ldle
speed
control
valve
faulty



Test
idle
speed
control
valve
.

c



d



e



Throttle
position
sensor
faulty
or
idle
signal
to



Test
throttle
position
sensor
.
DME
control
module
missing
.

c



d



h



i



Mass
air
flow
sensor
faulty



Test
mass
air
flow
sensor
Repair
Group
130
a



b



c



d



e



h



Large
air
intake
system
leak



Check
for
major
intake
air
leaks
downstream
of
mass
air
flow
sensor
.

a



c



d



e



g



h



Fuel
pressure
too
low



Test
fuel
pressure
.
Repair
Group
130

?



I



F
ue
l
pr
essu
r
e
t
oo
high



T
est
f
u
el
pressure
.
Repair
Group
130
d



e



g



h



Fuel
pump
delivery
volume
too
low



Test
fuel
pump
delivery
volume
.
Repair
Group
160
a



c



e



f



h
q
C
oo
l
a
nt
t
e
mp
e
r
a
t
u
r
e
se
n
so
r
f
au
lty



--]
T
est
coo
l
a
n
t
temp
erature
sensor
.

c



e



~



f



i



~
Fuel
injectors
leaking



Check
fuel
injectors
and
replace
leaking
injectors
.

~
Repair
Group
130

Throttle
plate
binding
or
incorrectly
adjusted



Check
throttle
plate
and
adjust
if
necessary
.

a



c



Electrical
connections
loose,
broken,
or
cor-



Visually
inspect
connectors
and
correct
any
roded



faults
.
Repair
Group
600
Ground
connections
loose,
broken,
or
corroded



Visually
inspect
ground
connections
and
correct
any
faults
.
Repair
Group
600

c



e
~



f



CO
content
too
high



Test
air
flowor
mass
air
flow
sensor
.
Repair

~
Group
130
a



b



c



d



e



CO
content
too
low



Test
mass
air
flow
sensor
.
gb



c



d



e



f



g



h



i



Inputsignals
to
ECM
missing,
ECM
in
limp



Make
electrical
tests
at
DMEECM
relay
.
Repair

home
mode



Group
130
a
~
b
~
c
~
d



e]



f



g



h



i



ECM
faulty



Test
DMEECM
inputs
.
If
all
inputs
are
correct,
replace
ECM
.

DRIVEABILITY
TROUBLESHOOTING

2
.
Remove
cooling
duct
or
terminal
cover
from
rear
of
al-



2
.
Remove
air
cleaner
upper
section
with
mass
air
flow
ternator
.



sensor
.

3
.
Check
for
battery
voltage
between
ground
and
terminal



3
.
Remove
terminal
cover
from
rear
of
alternator
.
Discon
B+
at
back
of
alternator
.
Then
turn
ignition
on
and



nect
wiring
.
check
for
battery
voltage
between
terminal
D+
and
ground
.
See
Fig
.
3
.
lf
voltage
is
not
present
at
either



4
.
Remove
drive
belt
from
alternator
pulley
.
See
020
point,
check
wiring
for
faults
.



Maintenance
program
.

001
¡987
Fig
.
3
.



Terminal
B+
is
supplied
battery
voltage
directly
from
the
bat-
tery
.
Terminal
D+
is
supplied
battery
voltage
via
the
charge
warning
bulb
when
thekey
is
on
or
the
engine
is
running
.

4
.
lf
no
faults
are
foundup
to
thispoint,test
alternator
out-

put
using
a
load
tester
.

5
.
If
a
load
tester
is
not
available,
a
crude
output
test
can
be
done
by
running
engine
at
about
2000
rpmand
turn-
ing
on
electrical
loads
(fans,
lights
and
rear
window
de-
froster,
wipers)
.
With
al¡
accessories
on,
battery
voltage
should
be
above
12
.0
VDC
.

A
replacement
alternator
should
have
the
same
rating
as
the
original
.
Alternator
manufacturer
and
ampere
rating
are
normally
marked
on
the
alternator
housing
.
1
.
Disconnect
negative
(-)
battery
cable
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
vi¡¡
.

BATTERY,
STARTER,
ALTERNATOR



121-
5

6
.
Remove
upper
and
lower
mounting
bolts
and
lift
out
al-
ternator
.
See
Fig
.
4
.

NOTE
-

If
reusing
drive
belt,
mark
direction
of
rotation
on
belt
before
removing
.

5
.
On
M44
engine
with
hydraulic
belt
tensioner
:
Remove
tensioner
idler
pulley
(upper
roller)
from
alternator

bracket
.

Fig
.
4
.



Alternator
mounting
bolts
(arrows)
.

O



u
J
S
v~~

U

I



1
i
n
-12
.22

Alternator,
removing
and
installing



7
.
Installation
is
reverse
of
removal
.
Install
drive
belt
as

(4-cylinder
engine)



described
in
020
Maintenance
Program
.

Tightening
Torques

"
D+
vire
to
alternator
(M6
nut)
.
...
.
.
.
7
Nm
(53
in-lb)

"
B+
wire
to
alternator
(M8
nut)
..
.
.
.
.
.
13
Nm
(10
ft-Ib)

"
Pulley
to
alternator
(M16
nut)
...
..
..
60
Nm
(44
ft-Ib)

ALTERNATOR
SERVICE