1994 BMW M3 boot

Please
read
these
warnings
and
cautions

before
proceeding
with
maintenance
and
repair
work
.

CAUTION-

"
See
also
Warnings
onpage
vi¡



"
Beforedoing
any
electrical
welding
on
cars
equipped
with
ABS,
disconnect
the
battery
negative
(-)
terminal
(ground
strap)
and
the
"
If
you
lack
the
skills,
tools
and
equipment,
ora
suitable
work-



ABS
control
unit
connector
.
shop
for
any
procedure
described
in
this
manual,
we
suggest
you
leave
such
repairs
to
an
authorized
BMW
dealer
or
other
qualified



"
On
cars
equipped
with
anti-theft
radios,
make
sureyou
know
the
shop
.



correct
radio
activation
code
before
disconnecting
the
battery
or
removing
the
radio
.
lf
the
wrong
code
is
entered
into
the
radio
"
BMW
is
constantly
improving
its
cars
and
sometimes
these



when
power
is
restored,
that
radio
may
lock
up
and
be
renderedchanges,
both
in
parts
and
specifications,
are
made
applicable
to



inoperable,
even
if
the
correct
code
is
thenentered
.
earlier
models
.
Therefore,
part
numbers
listed
in
this
manual
are
for
reference
only
.
Always
check
with
your
authorized
BMW
dealer



"
Always
make
sure
ignition
is
off
before
disconnecting
battery
.
parts
department
for
the
latest
information
.
"
Label
battery
cablesbefore
disconnecting
.
Onsome
models,
"
Before
starting
a
job,
make
certain
that
you
have
all
the
neces-



battery
cablesarenot
color
coded
.
sary
tools
and
parts
on
hand
.
Read
al¡
the
instructions
thoroughly,
do
not
attempt
shortcuts
.
Use
tools
appropriate
to
the
work
and



"
Disconnecting
the
battery
may
erase
fault
code(s)
stored
in
con-

use
only
replacement
parts
meeting
BMW
specifications
.
Make-



trol
module
memory
Using
special
BMW
diagnostíc
equipment,
shift
tools,
parts
and
procedures
will
not
make
good
repairs
.



check
forfault
codes
prior
to
disconnecting
the
battery
cables
.If
the
Check
Engine
light
is
illuminated,
see100
Engine-General
for
"
Use
pneumatic
and
electric
tools
only
to
loosenthreaded
parts



On-Board
Diagnostics
(OBD)
fault
code
information
.
lf
any
other
and
fasteners
.
Never
use
these
tools
to
tighten
fasteners,
espe-



system
faults
have
been
detected
(indicated
by
an
ílluminated
cially
on
light
alloy
parts
.
Always
use
a
torque
wrench
to
tighten



warning
light),
see
an
authorized
BMW
dealer
.
fasteners
to
the
tightening
torque
specification
listed
.
"
If
a
normal
or
rapid
charger
is
used
to
charge
battery,
the
battery
"Be
mindful
of
the
environment
and
ecology
.
Before
you
drain
the



mustbe
disconnected
and
removed
fromthe
vehicle
in
order
to
crankcase,
find
outthe
proper
way
to
dispose
of
the
oil
.
Do
not



avoid
damaging
paint
and
upholstery
pour
oil
onto
the
ground,
down
a
drain,
or
into
a
stream,
pond
orlake
.
Dispose
of
in
accordance
withFederal,
State
and
Local
laws
.



"Do
not
quick-chargethe
battery
(for
boost
starting)
for
longer
than
one
minute
.
Wait
at
least
one
minute
before
boosting
the
bat-
e
If
battery
power
is
lost
or
the
battery
has
been
disconnected,
the



tery
a
second
time
.
powerwindows
must
be
re-initialized
.
Both
one
touch
up/down
and
pinch-protection
will
be
inactive
until
windows
are
re-initial-



"
Connect
and
disconnect
a
battery
charger
only
with
the
battery
ized
.
See
512
Door
Windows
.



charger
switched
off
.

"
The
control
module
for
the
anti-lock
brake
system
(ABS)
cannot
withstand
temperatures
from
a
paint-drying
booth
or
aheat
lamp
in
excess
of
203°F
(95°C)
and
should
not
be
subjected
to
temper-
atures
in
excess
of
185°F
(85°C)
for
more
than
twohours
.

"
Sealed
or
"maintenance
free"
batteries
shouldbeslow-charged
only,
at
anamperage
ratethat
is
approximately
10%
of
the
bat-
tery's
ampere-hour
(Ah)
rating
.

"
Do
not
allow
battery
chargingvoltage
to
exceed
16
.5
volts
.
If
the
battery
begins
producing
gas
or
boiling
violently,
reduce
the
charg-
ing
rate
.
Boosting
a
sulfated
battery
at
a
high
charging
rate
can
cause
an
explosion
.

020
Maintenance
Program

GENERAL
.
.
...
.
.
.
...
.
.
.
.
.
.
.
.
.
.
.
...
.
..
020-2

BMW
Service
Indicator
......
..
....
..
...
..
.
020-2

Oil
Service
.....
.
..........
..
...
...
...
..
.
020-2

Inspection
I
and
Inspection
II
.
..
....
..
...
..
.
020-2

Resetting
Service
Indicator
....
.
....
..
...
..
.
020-3

MAINTENANCE
TABLES
..
.
.
.
.
.
........
020-3

FLUID
AND
LUBRICANT

SPECIFICATIONS
.
.
.
.
.
.
.
...
.
.
.
....
.
...
020-8

Manual
Transmission
Fluid
..
.
.
.
.
.
....
.
.
.
.
020-8

Automatic
Transmission
Fluid
.
.
.
.
.
....
.
.
.
.
020-8

Final
Drive
Gear
Oil
................
.
.
.
.
020-9
Brake
Fluid
.
.
.
.
.
................
.
.
.
.
020-9
Engine
Coolant
(Anti-freeze)
.
.
...
.
....
.
.
.
.
020-9

Power
Steering
Fluid
........
..
......
.
.
.
.
020-9

ENGINE
OIL
SERVICE
.
.
...
.
.
.
...
.
.
.
.
.
.
020-9

Engine
oil,
checking
leve¡
..
...
...
..
........
020-9
Engine
oil
and
filter,
changing
....
.
......
.
..
020-9

ENGINE
COMPARTMENT

MAINTENANCE
...
.
.
.
.
.
.
.
.
.
.
.
.
.
......
020-10

Air
filter,
replacing
.
...
...
.
.....
.
.....
.
...
020-11

Spark
plugs,
replacing
...
.
......
.
...
..
...
020-11

¡dle
Speed
.
..
...
...
....
.
......
.
...
..
...
020-12

Battery,
checking
and
cleaning
.......
..
...
020-12

Battery,
replacing
.
.....
.
.....
.
.....
..
...
020-12

Accelerator
and
Throttle
Linkage
.
.....
..
...
020-13

Engine
DriveBelts
.....
.
....
..
...
...
...
.
020-13

V-belt,
replacing

(4-cylinder
engines
built
up
to
1/94)
..
....
.
020-13

Poly-ribbed
belt,
replacing

(4-cylinder
engines
built
from
1194

and
all
6-cylinder
engines)
.
.
....
..
......
020-13

Cooling
System
Service
.
...
..
....
..
....
..
020-14

Power
steering
fluid,
checking
leve¡
.
..
....
.
.
020-14

Oxygen
Sensors
....
...
..
..
....



.
.....
.
.
020-15

MAINTENANCE
PROGRAM



020-1

UNDER-CAR
MAINTENANCE
.
..
.
...
.
.
.020-16
'

Fuel
filter,
replacing
...
.
.....
..
.....
..
..
.020-16

Tires,
checking
inflation
pressure
.
.....
.
....
020-17

Tires,
rotating
...
..
.....
..
....
..
....
.
....
020-17

Wheels,
aligning
..
.....
.
...........
.
....
'020-17

Brake
system,
inspecting
.
.
....
.
.....
..
...
020-17

Brake
pad/rotor
wear,checking
.
......
.
....
020-17

Brake
fluid,
replacing
.........
..
.



..
..



.
020-17

Parking
brake,
checking
......
.
.....
..
....
020-17

Exhaust
system,
inspecting
....
..
.....
.
...
.020-18

Manual
Transmission
Senrice
..
..
.....
.
....
020-18

Manual
transmission
fluida

checking
and
filling
..
.
....
..



.
.
..
..
....
020-18

AutomaticTransmission
Service
.
....
...
....
020-18

Front
suspension
and
steeringlinkages,
inspecting
..
.
:.....
.
....
..
.....
..
...
.
.020-18

Rear
suspension,
inspecting
.
..
...
...
....
..
020-18

Final
drive
oil
leve¡,
checking
.
.
.
...
....
...
..
020-18

Fuel
tank
and
fuel
lines,
inspecting
.
.....
....
020-19

Clutch
fluid,
checking
...
...
...
...
....
.....
020-19

Drive
axle
joint
boots,
inspecting
...
..
.....
..
020-19

BODY
AND
INTERIOR

MAINTENANCE
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
.
.020-19
Windshield
Wiper
Blade
Maintenance
....
.
.
020-19

Body
and
hinges,
lubricating
.
.....
..
......
.
020-19

Seat
Belts
...
..
...
...
...
..
.....
..
.....
.
.
020-20

Exterior
Washing
..
...
...
..
.
.
...
..
......
.020-20

Waxing
.....
..
...
...
...
..
.....
..
.......
020-20

Polishing
..
...
...
...
....
..
..........
..
.
.'020-20

Washing
Chassis
.
...
....
.
....
..
.....
.
...
020-20

Special
Cleaning
.
.
.....
..



...
.
.....
..
..
.020-20

Interior
Care
.
....
..
....
..
..



.
.
......
.
...
020-20

Leather
Upholstery
and
Trim
...
..
....
...
...
020-20

TABLES

a
.
Oil
Service
......
...
.
..
.............
...
---
020-4

b
.
Inspection
1
Service
..
.
.
.............
....
...
020-5

c
.
Inspection
11
Service
.
.
...
...........
..
.
..
..
020-6

d
.
Scheduled
Maintenance-Time/Mileage
Intervals
..
020-7

e
.
Fluids
and
Lubricants
..
...
...........
.....
..
020-8

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

020-
1
8



MAINTENANCE
PROGRAM

Fig
.
25
.
Inspect
brake
pads
with
the
caliper
removed
.
Minimum
brake
pad
thickness
shown
by
dimension
(A)
.

NOTE-

The
parking
brake
may
lose
some
of
its
effectiveness
if
it
is
not
used
frequently
.
This
is
due
to
corrosion
build-
up
on
the
parking
brake
drum
.
To
remove
corrosion,
ap-
plythe
parking
brake
just
until
it
begins
togrip,
then
pulí
the
lever
up
one
more
stop
(click)
.
Drive
thecar
approx-
imately
400
meters
(1,300
ft
.)
and
release
the
brake
.
To
recheck
the
adjustment
of
the
parking
brake
see340
Brakes
.

UNDER-CAR
MAINTENANCE

0011920

Manual
transmission
fluid,

checking
and
filling

The
manual
transmission
fluid
leve¡
should
be
checked
at

specified
intervals
.
Check
and
fill
the
transmission
with
the
car

ona
leve¡
surface
.
Transmission
(luid
leve¡
checking
and
re-

placement
procedures
are
covered
in
230
Manual
Transmis-

sion
.

Automatic
Transmission
Service

The
automatic
transmission
is
not
equipped
with
a
dipstíck
.

Therefore,
checking
the
ATF
level
is
an
ínvolved
procedure,

which
includes
measuring
and
maintaining
a
specified
ATF

temperature
during
the
checking
procedure
.

For
more
complete
ATF
service,
including
checking
ATF
lev-

e¡
and
ATF
filter
replacement
procedures,
see
240
Automatic
Transmission
.

Front
suspension
and
steering
linkages,

inspecting

Inspection
of
the
front
suspension'and
steering
includes
a
check
of
all
moving
parts
for
wear
and
excessive
play
.
Also
in-

spect
the
rubber
seals
and
boots
for
cracks
or
tears
that
could

allow
the
entry
of
dirt,
water,
and
other
contaminants
.
See
310

Front
Suspension
.

Exhaust
system,
inspecting



Rear
suspension,
inspecting
Exhaust
system
life
varies
widely
according
to
driving
habits



Final
drive
and
rear
drive
axle
service
consists
of
checking

and
environmental
conditions
.
If
short-distance
driving
pre-



and
changing
the
gear
oil,
inspecting
for
leaks,
and
checking
dominates,
the
moisture
and
condensation
in
the
system
will



the
rear
drive
axle
rubber
boots
for
damage
.
not
fully
dryout
.
This
will
lead
to
early
corrosion
damage
and
more
frequent
replacement
.
The
areas
where
leaks
are
most
likely
to
occur
are
around
the
driveshaft
and
drive
axle
mounting
flanges
.
For
more
infor

Scheduled
maintenance
of
the
exhaust
system
is
limitedlo



mation
on
ídentifying
oil
leaks
and
their
causes,
see330
Rear
inspection
.
Check
for
restrictions
due
to
dents
or
kinks
.
Check



Suspension
.
for
weakness
or
perforation
due
to
rust
.
Check
lo
see
that
all
the
hangers
are
in
place
and
properly
supporting
the
system
and
that
the
system
does
not
strike
the
body
.
Alignment
of
the
sys-



Final
drive
oil
leve¡,
checking

temand
the
location
of
the
hangers
aredescribed
in
180
Ex-
haust
System
.



Check
the
lubricant
leve¡
with
thecar
level
.
Remove
the
oil
filler
plug
.
The
leve¡
is
correct
when
the
fluidjust
reaches
the

edge
of
the
filler
hole
.
Install
and
tighten
the
oil
filler
plug
when
Manual
Transmission
Service



the
oil
level
is
correct
.
See
Fig
.
26
.

Manual
transmissionservice
consists
of
inspectingfor
leaks



The
final
drive
should
be
filled
with
a
special
BMW
lubricant
and
checking
and
changing
the
fluid
.



available
through
an
authorized
BMW
dealer
.
In
addition,
the
lubricant
type
varies
depending
onwhether
or
nota
limited-slip
Evidence
of
transmissionleaks
is
fkely
to
beseenaround
the



differential
is
fitted
.
driveshaft
mounting
flange
and
at
the
bottom
of
the
bellhousing
.
For
more
information
on
identifying
oil
leaks
and
their
causes,
see230ManualTransmissionand210
Clutch
.



Tightening
Torque

"
Finaldrive
filler
plug
to
final
drive
housing
..................
70
Nm
(52
ft-Ib)

NOTE-

Use
a14
mm
or17
mm
alíen
bit
socket
to
remove
the
drain
plug
.

"
If
thecar
is
raised
in
the
air,
it
shouldbe
leve¡
.

Fuel
tank
and
fuel
fines,
inspecting

0012474

Inspect
the
fuel
tank,
fuel
lines,
and
fuel
system
for
damage

or
leaks
.
Check
for
fuel
leaks
in
the
engine
compartment
or

fuel
odors
in
the
passenger
compartment
.
Check
for
faultyfuel

lines
bybending
them
.
If
any
leaks
are
present,
fuel
should
be

expelled
.
Check
for
any
evaporative
emissions
hoses
that

may
have
become
disconnected,
checking
carefully
at
the

charcoal
canister
and
evaporative
emissionspurge
system
.

See130
Fuel
Injection
and
160
Fuel
Tank
and
Fuel
Pump

for
component
locations
and
additional
information
.

WARNING
-

When
checking
for
fuel
leaks,
the
engine
must
be
cold
.
A
hot
exhaust
manifold
or
exhaust
system
could
cause
the
fuel
to
ignite
or
explode
causing
se-
rious
personal
injury
.
Uentilate
the
workarea
and
clean
up
spilled
fuel
immediately
.

Clutch
fluid,
checking

The
hydraulic
clutch
and
the
brake
system
share
the
same

reservoir
and
the
same
brake
fluid
.
Clutch
fluid
leve¡
and
brake

fluid
level
are
checked
at
the
same
time
.
See340
Brakes
for

more
information
.
See210
Clutch
for
information
on
the
clutch

and
the
hydraulic
clutch
operating
system
.

MAINTENANCE
PROGRAM



020-19

Drive
axie
joint
boots,
inspecting

100
Engine-General

The
protective
boots
must
be
closely
inspected
for
cracks
andany
other
damage
that
will
allow
contaminants
to
get
ínto
the
joint
.
If
the
rubber
boots
faf
,
the
water
and
dirt
that
enter
the
joint
will
quickly
damage
¡t
.
Replacement
of
the
drive
axle
joint
boots
and
inspection
of
the
joints
are
described
in
330
Rear
Suspension
.

BODY
AND
INTERIOR
MAINTENANCE

Windshield
Wiper
Biade
Maintenance

Common
problems
with
the
windshield
wipers
include

streaking
or
sheeting,
water
drops
after
wiping,
and
blade
chat-

ter
.
Streaking
is
usually
caused
when
wiper
blades
are
coated

with
road
film
or
car
wash
wax
.
Clean
the
blades
using
soapy
water
.
If
cleaning
theblades
does
not
cure
the
problem
then

they
should
be
replaced
.
BMW
recommends
replacing
the
wip-
er
blades
twice
a
year,
before
and
after
the
cold
season
.
Onold-

er
cars,
check
the
tension
spring
that
holds
the
wiper
to
the

glass
.
Replace
the
wiper
arm
if
the
springs
are
weak
.

Drops
that
remainbehind
after
wipingare
caused
by
oil,
road

film,
or
diesel
exhaust
coating
the
windshield
.
Use
an
alcohol
or

ammonia
solution,
or
a
non-abrasive
cleanser
to
clean
the

windshield
.

Wiper
blade
chatter
may
be
caused
by
dirty
or
worn
blades,

bya
dirty
windshield,
or
by
bentor
twisted
wiper
arms
.
Clean

the
blades
and
windshield
as
described
above
.
Adjust
the
wiper

arm
so
that
there
is
even
pressure
along
the
blade,
and
so
that

the
blade
is
perpendicular
to
the
windshield
atrest
.
Lubricate

the
wiper
linkage
with
a
light
oil
.
The
linkage
is
located
under

the
hood
on
the
drivers
side
.
If
the
problem
persists,
theblades
are
excessively
aged
or
worn
and
should
be
replaced
.
See
611
Wipers
and
Washers
.

Body
and
hinges,
lubricating

The
door
locks
and
lock
cylinders
canbe
lubricated
with
an

oil
that
contains
graphite
.

The
body
and
door
hinges,
the
hood
latch,
and
the
door

check
rods
should
be
lubricated
with
SAE
30
or
SAE
40
engine

oil
.
Lubricate
the
seat
runners
with
multipurpose
grease
.
Do
not

apply
any
oil
to
rubber
parts
.
If
door
weatherstrips
are
sticking,

lubricate
them
with
silicone
spray
or
talcum
powder
.
The
hood

release
cable
should
be
lubricated
as
well
.

The
use
of
winter
lock
de-icer
spraysshould
be
kept
to
an
ab-

solute
minimum,
as
the
alcohol
in
the
de-icer
will
wash
the

grease
out
of
the
lock
assemblies,
and
may
cause
the
locks
to

corrode
internally,
or
become
difficult
to
operate
.

ENGINE-GENERAL
100-1

130-
8



FUEL
INJECTION

Fig
.
8
.



Fuel
pump
relayterminal
identification
.
1.
Peel
back
rubber
boot
on
oxygen
sensor
electrical
har-
ness
connector
(car
wiring
side)
.
With
connector
at-
Oxygen
sensor,
testing



tached
to
sensor,
connect
digital
voltmeter
to
pins
1
(BOSch
systems
only)



and
2
in
rear
of
connector
.
See
Fig
.
10
.

CAUTION-

"
The
information
inthis
sectionapplies
to
Bosch
engine
management
systems
only
.

"
The
Siemens
MS
41
.1
system
uses
resistive-type
oxygen
sensors
.
This
sensor
uses
a
5-volt
refer-
ence
signal
input
and
the
output
to
the
ECM
var-
ees
from
1-5
volts,
in
stepped
increments
based
on
oxygen
content
in
the
exhaust
.

NOTE-

"
On
pre-08D
11(1992-1995)
cars,
there
is
one
oxygen
sensor
mounted
upstream
of
the
catalytic
convert-
er(s)
in
the
exhaust
pipe
.
See
Fig
.
9
.
"
On
OBD
11
cars
(1996-1998)
cars,
there
is
one
oxygen
sensor
before
andone
after
each
catalytic
converter
.

"
OnM52
and
S52US
engines,
the
front
pairof
oxygen
sensors
are
installed
in
the
exhaust
manifolds
.

The
oxygen
sensor
providesan
input
voltage
signal
(0-1
VDC)
to
the
ECM
based
on
the
oxygen
content
in
the
exhaust
gas
.
TO
generate
voltage,
the
sensor
temperature
must
exceed
575°F
(300°C)
.
Therefore
it
ís
electrically
heated
.

NOTE-

"
The
test
given
below
is
not
a
conclusive
test
of
oxygen
sensor
efficiency
and
does
not
test
how
quickly
the
oxygensensor
can
react
to
changing
conditions
.

"
Pin
numbers
and
wirecolors
can
vary
.
Always
check
the
wiring
diagrams
to
conflrm
wire
color
and
pinas-
signment
.

ELECTRICAL
CHECKS
AND
COMPONENT
TESTING

0013135

Fig
.
9
.



Oxygen
sensor
location
(arrow)
ahead
of
catalytic
converter
.
3181
model
with
M42
engine
shown
.

1
.
Black
(ground)
2
.
Grey
(signal)



4
.
White
(heater
circuit)
3
.
White
(heater
circuit)

0013189
Fig
.
10
.
Oxygen
sensor
connector
terminal
identification
(sensor
sede)
.
Terminals
numbers
are
molded
into
connector
.

2
.
Start
engine
.
Oxygen
sensorshould
start
to
output
a
fluctuating
voltage
within
a
short
period
.
If
voltage
is
in-
correct,
turn
engine
off
and
check
preheater
circuit
as
described
below
.

WARNING
-

Exhaust
manifolds
and
pipes
can
be
hot
enough
to
cause
serious
burns
.
Wear
suitable
heavy
gloves
and
other
appropriate
protection
.

130-
1
4



FUEL
INJECTION

NOTE-

Be
sure
to
retrieve
thrust
washer
behind
fuel
pressure
regulator
on
6-cylinder
engine
.

4
.
Installation
is
reverse
of
removal
.
Replace
O-rings
.

Fuel
pressure
regulator,
replacing

(under
car
mount)

WARNING
-

Fuel
will
be
discharged
.
Do
not
disconnect
any
wires
that
could
cause
electrical
sparks
.
Do
not
smoke
or
work
near
heaters
or
other
fire
hazards
.
Keep
an
approved
tire
extinguisher
handy
.

On
late
4-
and
6-cylinder
cars,
the
fuel
pressure
regulator
is

mounted
beneath
the
left
sideof
the
car,
under
a
protective

cover
.
See
Fig
.
20
.

0012726

Fig
.
20
.
Fuel
pressure
regulatorlocation
underneath
car
(arrow)
.
Vac-
uum
hose
to
regulator
is
shown
at
A
.
(Protective
cover
has
been
removed
.)

5
.
Installation
is
reverse
of
removal
.
Replace
O-rings
.

BOSCH
DME
Ml
.
7
COMPONENT
TESTS
AND
REPAIRS

BOSCH
DME
Ml
.7
COMPONENT

TESTS
AND
REPAIRS

CA
UTION-

Use
only
a
digital
multimeter
when
testing
compo-
nents
and
wiring
.
Use
of
an
analog
VOM
may
damage
the
engine
control
module
.

4-cylinder
cars
with
M42
engines(1992
to
1995)use
the

Bosch
DME
M1
.7
fuel
injection
system
.

Electrical
tests
of
the
main
and
fuel
pump
relays
and
the

DME
engine
control
module
(ECM)
are
covered
earlier
in
this

section
.
Fuel
pump
tests
arecovered
in
160
Fuel
Tank
and

Fuel
Pump
.

Air
flow
sensor,
testing
and
replacing

DME
M1
.7
fuel
injection
uses
a
volume
air
flow
type
sensor

with
integrated
intake
air
temperature
(IAT)
sensor
.
The
sen-

sor
provides
a
varyingvoltage
signal
to
the
ECM
based
on
the

position
of
the
air
vane
.
As
the
vane
doorswings
open
thepo-
tentiometer
increases
the
voltage
signal
to
the
ECM
.
The
IATsensor
adapts
theoutput
signal
to
the
ECM
based
on
intake

air
temperature
.

1
.
Check
ECM
reference
voltage
to
sensor
:

"
Peel
back
rubber
boot
from
air
flow
sensor
harness

connector
.

"
Turn
ignition
keyon
.
"
Check
for
5
volts
between
terminal
1
of
harness
con-
nector
and
ground
.
See
Fig
.
21
.

"
Turn
ignition
key
off
.

"
If
voltage
is
not
present
or
incorrect,
check
wring
from

ECM
and
check
air
flow
sensor
reference
voltage
out-

put
at
ECM
.
See
Table
h
.
1
.
Working
under
car
below
driver's
seat,
remove
protec-
tive
cover
from
below
fuel
pressure
regulator
.

"
Remove
intake
air
bootfrom
sensor
.
2
.
Remove
vacuum
hosefrom
fuel
pressure
regulator
.



"
Connect
a
digital
multimeter
(ohms)
across
terminais
1

and
2
.
Swing
air
flow
sensor
vane
through
its
travel
3
.
Remove
locking
clip
retaining
fuel
pressure
regulator
.



range
.
Resistance
should
change
steadily
without
in-

terruption
.
4
.
Wrap
a
shop
rag
around
regulator,
then
remove
regula-



"
If
any
faults
are
found,
the
air
flow
sensor
is
faulty
and
tor
from
213
way
valve
by
pullingstraight
out
.



should
be
replaced
.

2
.
Check
air
flow
sensor
potentiometer
:

3
.
Check
IAT
sensor
resistance
:

"
With
harness
connector
disconnected
at
air
flow
sen-
sor,
check
resistance
across
sensor
terminais
4
and
5

of
air
flow
sensor
.
Compare
tests
results
to
values
in
Table
d
given
later
.
If
any
faults
are
found,
the
air
flow
sensor
should
be
replaced
.

u0
I
.[
Ia

Fig
.
21
.
Air
flow
sensor
harness
connector
terminal
identification
.

4
.
Replacing
air
flow
sensor
:

"
Remove
large
band
clamp
attaching
air
boot
to
sensor
.

"
Remove
airfiltertop
cover,
then
remove
airflow
sensor

mounting
nuts
inside
cover
.

"
Reconnect
air
boot
and
harness
connector
.

Engine
coolant
temperature
(ECT)
sensor,

testing
and
replacing

The
engine
coolant
temperature
(ECT)
sensor
sends
con-

tinuous
engine
coolant
temperature
information
to
the
ECM
.

As
temperature
increases,
sensor
resistance
decreases
.

"
With
harness
connector
disconnected,
check
resis-

tance
across
sensor
terminals
.

"
Compare
tests
results
to
values
in
Table
d
.

FUEL
INJECTION



130-
1
5

0011984

Fig
.
22
.
M42
engine
coolant
temperature
(ECG
sensor
(arrow)
.

Table
d
.
Engine
Coolant
Temperature
Sensoror

Intake
Air
TemperatureSensor
Test
Values

(DME
1
.7)

Test
temperatures



Resistance
(k
ohms)
',

14±2°F(-10t1°C)



7-11
.6

68±2°F
(20
t
1
°C)



2
.1
-2
.9

176
±
2°F
(80
t
V
C)



0
.27-0
.40

The
ECT
sensor
is
located
under
number
one
intake
run-



'

ner
.
See
Fig
.
22
.
NOTE-

1
.
Check
ECM
referente
voltage
to
sensor
:



The
test
values
listed
represent
only
three
test
points
from
a
continuous
resistance
NTC
sensor
.
Check
the
"
Disconnect
harness
connectorfrom
ECT
sensor
.



full
linear
response
to
increasing
temperature
as
the
"
Turn
ignition
key
on
.



engine
warms
up
.
"
Check
for
5
volts
between
supply
voltage
(brown/red)

wire
of
harness
connector
and
ground
.



3
.
If
ECT
sensor
fails
these
tests,
it
is
faulty
and
should
be

"
Turn
ignition
key
off
.



replaced
.
If
no
faults
are
found,
reconnect
electrical
"
If
voltage
is
not
present
or
incorrect,
check
wring
from



harness
.

ECM
and
check
ECT
sensor
reference
voltage
output

at
ECM
.
See
Table
h
.
NOTE-

2
.
Check
ECT
sensor
resistance
:



Use
a
new
copper
sealing
washer
when
installing
sen-
sor
.
Reptace
any
lost
coolant
.

WARNING
-

Do
not
replace
the
ECT
sensor
unlessthe
engine
is

cold
.
Hot
coolant
can
scald
.

Tightening
Torque

"
ECT
sensor
to
cylinder
head
.....
..
13
Nm
(10
ft-Ib)

BOSCH
DME
M1
.7
COMPONENT
TESTS
AND
REPAIRS