1994 BMW M3 engine coolant
[x] Cancel search: engine coolantPage 122 of 759
119-
8
LUBRICATION
SYSTEM
17
.
Installation
is
reverse
of
removal
.
"
Thoroughly
clean
all
old
gasket
material
from
mating
surtaces
anduse
a
new
gasket
.
"
Applya
small
amount
of
non-hardening
sealer
(3-Bond
1209
0
or
equivalent)
to
oil
pan
gasket
directly
below
joints
for
and
cover
and
front
timing
case
cover
.
See
Fig
.
12
.
"
Tighten
oil
pan
bolts
starting
at
front
first,
working
to-
wardback
(transmission)
end
.
"
Fill
engine
with
oil
as
described
in
020
Maintenance
Program
.
"
After
addingengine
oil,
start
and
run
engine
.
Raiseen-
gine
speed
to
2,500
rpm
until
oíl
pressure
warning
lampgoes
out
(about
5seconds)
.
OIL
PUMP
applied
(arrows)
.
Apply
a
bead
3
mm
wideby
2
mm
high
.
WARNING
-
"
Always
use
new
bolts
when
mounting
the
sub-
frame
to
the
body
.
The
one-time
only
bolts
should
be
replaced
any
timethey
are
removed
.
"
Special
installation
instructions
apply
when
in-
stalling
the
front
suspension
crossmember
to
the
body
.
See
310
Front
Suspension
for
fastener
specifications
and
tightening
torques
.
Fig
.
12
.
Joint-mating
areas
at
oil
pan
gasket
where
sealer
should
be
Center
the
steering
spindle
to
the
steering
rack
before
in-
stalling
the
steering
column
shaft
.
See
320
Steering
and
Wheel
Alignment
for
more
specific
procedures
.
Tightening
Torques
"
Control
arm
bushing
carrier
to
body
(M10
bolt)
...............
47
Nm
(35
ft-Ib)
"
Engine
mount
to
suspension
crossmember(M10
nut)
..
42
Nm
(31
ft-Ib)
"
Oil
pan
to
engine
block
(M6
bolt)
8
.8
grade
...........
.......
....
10
Nm
(89
in-lb)
10
.9
grade
...........
..
...
...
.
12
Nm
(106
in-lb)
"
Stabilizer
bar
link
to
control
arm
(M10
nut)
.......
....
42
Nm
(31
Ib-ft)
"
Steering
column
universal
joint
to
steering
rack
spindle
(M8
bolt)
....
19
Nm
(14
ft-Ib)
"
Suspensíon
crossmember
to
body
...
...
.
...
..
.
.
See
310
Front
Suspension
OIL
PUMP
Oil
pump,
removing
and
installing
(4-cylinder
engine)
Oil
pressure
on
M42
and
M44
engines
is
generatedbya
gear-type
pump
mounted
to
the
rear
of
the
front
engine
cover
(timing
chaincase)
.
The
pump
is
gear-driven
off
the
front
of
the
crankshaft
.
NOTE-
Oil
pump
removal
requires
lowering
of
the
front
sus-
pension
and
removal
of
the
oil
pan,
as
well
asremoval
of
the
timing
chain
assembly
.
1
.
Disconnect
negative
(-)
battery
cable
from
battery
.
CAUTION-
Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
paga
vÍii
.
2
.
Drain
engine
oil
as
described
in
020
Maintenance
Pro-
gram
.
3
.
Withengine
cold,
drain
coolant
.
See
170
Radiator
and
Cooling
System
.
4
.
Remove
top
cover
from
oil
filter
housing
to
allow
engine
oil
to
drain
into
oil
pan
.
Remove
oil
pan
as
described
earlier
.
Reinstall
oil
filter
cover
.
5
.
Remove
alternator
.
Unbolt
power
steering
pump
from
bracket,
then
remove
alternator
mountíng
bracket
.
See
121
Battery,
Starter,
Alternator
.
6
.
Remove
crankshaft
vibration
damper
andhub
.
Then
re-
move
upper
and
lower
timing
chain
covers,
complete
timingchain,
chain
sprockets
and
chain
guides
.
See
117
Camshaft
Tíming
Chain
.
Page 125 of 759
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
Page 130 of 759
120-
6
IGNITION
SYSTEM
Crankshaft
position/rpm
sensor,
testing
and
replacing
(front
mounted)
1
.
Disconnect
sensor
harness
connector
.
2
.
Using
a
digital
multimeter,
check
resistance
between
terminals
1
and
2
in
connector
.
See
Fig
.
10
.
n1
n2n3
Fig
.
10
.
Crankshaft
position/rpm
sensorconnector
.
Crankshaft
positionlrpm
sensor
specifications
"
Coil
resistance
(approx
.)
terminais
1
and
2
....
.
..
...
....
1280
±
10%
ohms
"
Air
gap
(sensor
distance
from
toothed
wheel)
..
.
.
........
.1
.0
±
0
.3
mm
(0
.04
±
0
.01
in
.)
3
.
If
the
resistance
is
not
correct,
the
sensor
is
faulty
and
should
be
replaced
.
NOTE
-
When
installing
the
new
sensor,
be
sure
thewiring
Is
rerouted
in
the
same
orientation
.
Secure
the
sensor
us-
ing
new
wire
ties
.
Tightening
Torque
"
Crankshaft
position/rpm
sensor
to
mounting
bracket
.........
.
.
5
t
1
Nm
(62
t
9
in-lb)
Crankshaft
position/rpm
sensor,
4
.
Installation
is
reverse
of
removal
.
Use
a
new
O-ring
replacing
(rear
mounted)
when
installing
sensor
.
Be
sure
wiring
is
rerouted
in
same
orientation
.
1
.
Disconnect
sensor
harness
connector
.
6502AGN56
2
.
Locatesensor
on
rear
left
sideof
cylinder
block
.
Re-
move
sensormounting
bolt
and
remove
sensorfrom
cylinder
block
.
IGNITION
SYSTEM
SERVICE
3
.
Installation
is
reverse
of
removal
.
Use
a
new
O-ring
when
installing
sensor
.
Be
sure
wiring
is
rerouted
in
same
orientation
.
Secure
sensor
using
new
wire
ties
.
NOTE-
It
may
be
easier
to
remove
the
sensor
working
from
the
underside
of
the
vehicle
.
Camshaft
Position
(CMP)
Sensor
The
camshaft
position
(CMP)
sensor
is
usedby
the
engine
management
system
for
sequential
fuel
injection
and
knock
control
.
Camshaft
position
(CMP)
sensor,
replacing
(4-cylinder
engine)
1
.
Remove
CMP
sensorfromtop
timing
cover,
just
above
coolantthermostat
housing
.
See
Fig
.
11
.
Fig
.
11
.
Camshaft
position
sensor
mounting
bolt
(arrow)
.
M42
engine
shown
.
2
.
On
M42
engines
to
9/93
:
Disconnect
CMP
harness
plug
just
above
oil
filter
housing
.
3
.
On
M42
from9/93
and
all
M44
engines
:
Remove
upper
intake
manifold
as
described
in
113
Cylinder
Head
Re-
moval
and
Installation
.
Then
unplug
CMP
sensor
har-
ness
connector
below
manifold
.
Page 147 of 759
GENERAL
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.........
130-2
Intake
air
temperature
(IAT)
sensor,
Principles
of
Operatinn
.
.
.
.
.
.
.
.
.
.........
130-2
testing
and
replacing
...
.
...
.
.
.
.......
.
130-19
Basic
Engine
Settings
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
:
.
130-3
Throttle
position
sensor
(TPS),
DISA
(Dual
Resonance
Intake
System)
.
.
.
.
.
130-3
testing
and
replacing
...
.
...
.
.
.
.
.
...
.
.
.130-19
On-Board
Diagnostics
(OBD)
Idle
speed
control
valve,
testing
.
.
.
.
.
.
.
.
.
.
130-20
and
Fault
Diagnosis
.
.
....
.
......
.
.
.
...
130-4
Idle
speed
control
valve,
replacing
.
.
.
.
.
.
..
130-21
SecondaryAir
Injection
.
.
.....
.
.........
.
130-5
BOSCH
DME
M5
.2
COMPONENT
Warnings
and
Cautions
.
.
...
.
.
.
.........
.
130-6
REPLACEMENT
.....
.
......
.
....
.
.
.
..
130-21
ELECTRICAL
CHECKSAND
Mass
air
flow
sensor,
replacing
.
.
....
.
....
130-22
COMPONENT
TESTING
.
.
.
.
.
.
.
.
...
.
.
.
.
.
130-7
Engine
coolant
temperature
(ECT)
Main
sensor,
replacing
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
130-22
rela
y
testing
130
-7
,...
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
Intake
air
temperature
(IAT)
sensor,
Fuel
pump
relay,
testing
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
130-7
rep
lacin
.
.
.
.
.
.
.
.
.
.
.g
.
.
.
.
.
.
.
...
.
.
.
..
.130-22
Oxygen
sensor,
testing
(Boschsystems
only)
130-8
Throttle
poson
sensor
(TPS)
replacing
13022
,
..
.-
FUEL
DELIVERY
TESTS
...
.
....
.
.
.
...
.
130-9
Idle
speed
control
valve,
replacing
...
.
....
.130-23
Operating
fuel
pump
for
tests
.
.
.......
.
...
130-9
SIEMENS
MS
41
.1
COMPONENT
Relieving
fuel
pressure
and
REPLACEMENT
.
...
.
.
.
.
.
.......
.
....
.130-23
connecting
fuel
pressure
gauge
......
.
..
130-10
Residual
fuel
pressure,
testing
.
.....
.
.
.
.
.
130-10
Mass
air
flow
sensor,
replacing
.
.......
.
.
.130-25
Fuel
pressure
regulator
response
Engine
coolant
temperature
(ECT)
to
engine
load,
testing
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
130-11
sensor,
replacing
.....
.
.
.
.
.
.........
.130-25
Fuel
rail
and
injectors,
checking
...
.
.
.
.
.
.
.
130-11
Intake
air
temperature
(IAT)
sensor,
replacing
.
.
.
.
.
.....
.
.
.
.
.
.
.
.......
.
.
.130-25
Fuel
rail
and
injectors,
replacing
..
.
.
.
.
.
.
.
130-12
Throttleposition
sensor
(TPS),
replacing
.
.
.
130-26
Fuel
PressureRegulator
.........
.
.
.
.
.
.
.
130-13
Idle
s
eed
control
valve,
re
lacin
130-26
Fuel
pressure
regulatorreplacing
p
p
g
.'''...
.
'
,
(fuel
rail
mount)
...
.
.
.
.
.
.............
130-13
ECM
PIN
ASSIGNMENTS
.............
.
.
130-26
Fuel
pressure
regulator,
replacing
Engine
control
module
(ECM),
accessing
...
130-26
(undercar
mount)
.
.
.
.
.
.
.
.
.........
.
.
130-14
BOSCH
DME
M1
.7
COMPONENT
TESTS
AND
REPAIRS
.
.
.
.
.
...
.
.
.
.
.
.
.
.
130-14
Air
flow
sensor,
testing
and
replacing
.
.
.
.
.
.
130-14
Engine
coolant
temperature
(ECT)
sensor,
testing
and
replacing
...
.
.
.
.
.
.
.
.
130-15
Throttle
position
sensor
(TPS),
testing
and
replacing
.
..........
.
.....
130-16
Idle
speed
control
valve,
testing
and
replacing
.
.
.
.
.
............
130-16
BOSCH
DME
M3
.1
AND
M33
.1
COMPONENT
TESTS
AND
REPAIRS
.
.
.
130-17
Mass
Air
Flow
Sensor
.
.
.
.
.
.
.
.
.....
.
.
.
.
.130-17
Mass
air
flow
sensor
(hotwire),testing
and
replacing
.
.
.
.
.
.....
.
.
.
.
.
.
.
130-17
Mass
air
flow
sensor
(hot
film),
testíng
and
replacing
.
.
.
.....
.
.
.
.
.
.
.
.
.
130-18
Engine
coolant
temperature
(ECT)
sensor,
testing
and
replacing
..
.
.
.
.
.
...
.
130-18
130
Fuel
i
n
jection
FUEL
INJECTION
130-1
TABLES
a
.
Engine
Management
System
Variants
.........
.130-2
b
.
Mass
Air
Flow
Sensor
Variants
..
.
..
..........
.130-2
c
.
Fuel
Pressure
Specifications
..
.
.
...
..........
130-11
d
.
Engine
Coolant
Temperature
Sensor
or
Intake
Air
Temperature
Sensor
Test
Values
(DME
1
.7)
...
.
130-15
e
.
ThrottlePosition
Sensor
Tests
(DME
1
.7)
......
.130-16
f
.
Engine
Coolant
Temperature
Sensor
or
Intake
Air
Temperature
Sensor
Test
Values
(DME
3
.1/3
.3
.1)130-19
g
.
Throttle
Position
Sensor
Tests
(DME
3
.1/3.3
.1)
.
.130-20
h
.
ECM
Pin
Assignment-Bosch
DME
M1
.7
....
.
..
.130-28
i.
ECM
Pin
Assignment-Bosch
DME
M3
.1
.......
.130-30
j
.
ECM
Pin
Assignment-Bosch
DME
M3
.3
.1
.....
.130-32
k
.
ECM
Pin
Assignment-Bosch
DME
M5
.2
.......
.
130-34
I.
ECM
Pin
Assignment-Siemens
DME
MS
41
.1
..
.
130-36
Page 148 of 759
130-2
FUEL
INJECTION
GENERAL
This
repair
group
covers
fuel
injection
system
component
testing
and
repair
.
Special
equipment
is
necessary
for
some
of
the
procedures
given
in
this
repair
group
.
If
you
do
not
have
the
equipment
required
to
do
the
job,
it
is
recommended
that
these
repairs
be
left
to
an
authorized
BMW
dealer
.
The
BMW
dealer
is
equipped
with
sophisticated
diagnostic
test
equip-
ment
that
is
capable
of
quicklypinpointing
hard-to-find
fuel
in-
jection
problems
.
NOTE-
"
Wiring
diagrams
for
the
engine
management
system,
can
be
found
at
the
rear
of
the
manual
under
Electri-
cal
Wiring
Diagrams
.
"
For
ignition
system
repairinformation,
see120
Igni-
tion
System
.
"
For
fuel
supply
system
testing
and
repair,
see160
The
engine
control
module
(ECM)
uses
electrical
signals
Fuel
Tank
and
Fuel
Pump
.
from
the
mass
air
flow
sensor,
the
air
and
coolant
temperature
sensors,
the
crankshaft
position/rpm
sensor,
the
knock
sen
Principies
Of
Operation
sors
and
the
oxygen
sensorsas
the
primary
inputs
to
electron-
ically
control
fuel
delivery
and
ignition
timing
.
There
are
five
versions
of
engine
management
systems
usedon
the
E36
cars
.
Each
has
the
same
basic
components
and
operating
principles
.
The
most
notable
difference
is
that
1996
and
later
cars
use
a
sophisticated
OBD
II-compliant
sys-
tem
.
See
Table
a
.
Table
a
.
Engine
Management
System
Variants
Engine
code/year
1
System
4-cy1inder
M42
(1
.8
I)
1992-1995
Bosch
DME
Ml
.7
M44
(1
.91)
1996-1998
~
Bosch
DME
M5
.2
(OBD
II)
6-cylinder
M50
1992
(2.5
I)
Bosch
DME
M3
.1
1993-1995
(2.5
I)
Bosch
DME
M3
.3.1
(VANOS)
M52
1996-1998
(3281-
2
.8
I)
Siemens
MS
41
.1
(OBD
II)
1998
(3231
-
2
.5
I)
Siemens
MS
41
.1
(OBD
II)
M-Power
S50US
(M3
-
3
.01)
1995
Bosch
DME
M3
.3
.1
S52US
(M3
-
3
.21)
1997-1998
Siemens
MS
41
.1
(0131)
11)
NOTE-
-
Descriptions
and
procedures
in
the
first
partof
this
re-
pairgroup
refer
to
all
the
various
engine
management
systems
.
"
Particulars
of
each
fuel
injection
system
are
treated
in
separate
sections
in
the
second
part
of
this
repair
group
.
GENERAL
Fig
.1
.
OBD
II
diagnostic
connector
locatíon
.
The
fuel
injection
system
is
completely
electronic
in
opera-
tion
.
Air
flow
is
measured
electronically
via
a
mass
air
flow
sensor
and
additional
sensors
supply
information
about
en-
gine
operating
conditions
.
The
ECM
calculates
the
amount
of
fuel
needed
for
the
correct
air-fuel
ratio
and
actuates
the
fuel
injectors
accordingly
.
The
amount
offuel
metered
to
theen-
gine
is
determined
by
how
long
the
injectors
are
open
.
Airintake
.
Air
entering
the
engine
passes
through
a
pleat-
ed
paper
air
filter
in
the
air
cleaner
.
Intake
air
volume
or
mass
is
then
measured
bya
mass
air
flow
(MAF)
sensor
.
In
al¡
ex-
cept
the
vane
type
sensor
(DME
M1
.7),
a
reference
current
is
used
to
heat
a
thin
wireor
film
in
the
sensor
when
the
engine
is
running
.
The
current
used
to
heat
the
wire/film
is
electroni-
cally
converted
into
a
voltage
measurement
corresponding
to
the
mass
of
the
intake
air
.
Table
b
.
Mass
Air
Flow
Sensor
Variants
System
Al
r
flow
sensor
type
Bosch
DME
M1
.7
Vane
(volume
sensor)
Bosch
DME
M3
.1
Hot
wire
(mass
sensor)
Bosch
DME
M3
.3
.1
Hot
film
(mass
sensor)
Bosch
DME
M5
.2
Hot
film
(mass
sensor)
Siemens
MS
41
.1
Hot
film
(mass
sensor)
"
The
16-pin
OBD
11
diagnostic
connector
is
located
on
NOTE-
the
lower
left
dashpanel
.
See
Fig
.
1
.
On
cars
equipped
wíth
tractioncontrol,
an
additional
throttle
valve
is
controlled
by
an
electronic
throttle
actu-
ator
(motor)
.
This
valve
is
used
for
engine
speed
inter
vention
.
Repair
information
forthis
system
is
notcovered
here
due
to
the
special
electrical
testing
equip-
ment
required
to
service
it
.
Page 161 of 759
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
Page 164 of 759
130-18
FUEL
INJECTION
The
engine
coolant
temperature
(ECT)
sensor
sends
con-
tinuous
engine
coolant
temperature
information
to
the
ECM
.
Fig
.
26
.
Mass
air
flow
sensor
terminalidentifcation
on
carswith
DME
As
temperature
increases
sensor
resistance
decreases
.
M3
.1
fuel
injection
.
Mass
air
flow
sensor
(hot
film),
testing
and
replacing
MOTE-
A
burn-off
cycle
is
not
used
on
hot
film
sensors
.
8
.
With
ignition
off,
disconnect
harness
connector
from
air
ECT
Sensor
Location
flow
sensor
.
Using
a
digital
multimeter,
check
resis-
"
M50/S50US
engine
............
left
side
of
cylinder
tance
at
terminals
listed
.
head
under
intake
manifold
Air
Flow
Sensor
Test
Values
(DMEM3
.1)
"
Terminals
5
and
6
.
.
.
.........
..
.
..
....
3-4
ohms
If
any
faults
are
found,
check
wiring
lo
and
from
the
ECM
.
Make
ECM
pinout
test
as
listed
in
See
Table
i
.
Main
power
to
air
flow
sensor
comes
from
DME
main
relay
.
On
cars
with
DME
M3
.3
.1
a
hot
film
mass
air
flow
sensor
is
used
.
When
the
engine
is
running,
a
current
is
used
lo
heat
a
thinfilm
in
the
center
of
the
sensor
.
This
current
is
electroni-
cally
converted
into
a
voltage
measurement
corresponding
to
the
mass
of
intake
air
.
If
thehot
film
breaks
or
if
there
is
no
output
from
the
air
flow
sensor,
the
ECM
automatically
switches
to
a
"limp-home"
mode
and
tucos
on
the
Check
Engine
light
.
The
engine
can
usually
be
started
and
driven
.
The
air
flow
sensor
has
no
inter-
nal
moving
parts
and
cannot
be
senricedor
adjusted
.
CA
UTION-
Use
only
a
digital
multimeter
when
checking
the
mass
air
flow
sensor
.
An
analogmetercan
dam-
age
the
air
flow
sensor
.
BOSCH
DME
M3
.
1
AND
M32
.1
COMPONENT
TESTS
AND
REPAIRS
1
.
Disconnect
harnessconnector
from
air
flow
sensor
.
2
.
Turn
ignition
on
and
check
for
voltage
and
ground
at
connector
.
There
should
beground
at
pin
1
.
There
should
be
positive
(+)
battery
voltage
at
pin
3
.
If
any
faults
are
found,
check
wiring
to
and
from
ECM
.
Make
ECM
pinout
test
.
See
Table
j
.
NOTE-
Positive
(+)
battery
voltage
to
air
flow
sensor
comes
from
DME
main
relay
when
the
ignition
is
switch
on
orengine
running
.
Engine
coolant
temperature
(ECT)
sensor,
testing
and
replacing
0012704
Fig
.
27
.
Engine
coolant
temperature
(ECT)
sensor
(A)
is
located
be-
neath
top
engine
cover
(B)
and
crankcase
vent
hose
(C)
.
M52
engine
shown
.
M50
is
similar
.
1
.
Check
ECM
reference
voltage
to
sensor
:
"
Disconnect
harnessconnector
from
ECT
sensor
.
"
Turn
ignition
keyon
.
"
Check
for
5
volts
between
supply
voltage
wire
(brown/red)
wire
of
harness
connector
and
ground
.
"
Turn
ignition
key
off
.
"
If
voltage
is'
not
present
or
incorrect,
check
wiring
from
ECM
and
check
referencevoltage
output
at
ECM
(pin
78)
.
See
Table
i
(DM
E
3
.1)
or
Table
j
(DME
3
.3
.1)
2
.
Check
ECT
sensor
resistance
:
"
With
harnessconnector
disconnected,
check
resis-
tance
acrosssensor
terminals
.
"
Compare
tests
results
to
values
in
Table
f
.
Page 165 of 759
Table
f
.
Engine
Coolant
TemperatureSensor
or
Intake
Air
TemperatureSensor
Test
Values
(DME
3
.113
.3
.1)
Test
temperatures
Resistance
(k
ohms)
14±
2°F
(-10
±
1'C)
7-11
.6
68±
2°F
(20
±
1'C)
2
.1
-2
.9
17612°F
(80
t
V
C)
0
.27-0
.40
NOTE
The
test
values
listed
represent
only
three
test
points
from
a
continuous
resistance
NTC
sensor
.
Check
the
full
linear
response
to
increasing
temperatures
as
the
engine
warms
up
.
3
.
If
ECT
sensor
fails
these
tests,
it
is
faulty
and
should
be
replaced
.
If
no
faults
are
found,
reconnect
electrical
harness
.
WARNING
-
Do
not
replace
the
ECT
sensor
unless
the
engine
is
cold
.
Hot
coolant
can
scald
.
NOTE-
Use
"
a
new
copper
sealing
washer
when
installing
sensor
.
Replace
any
lost
coolant
.
Tightening
Torque
"
Engine
coolant
temperature
sensor
to
cylinder
head
.........
..
.
..
...
13
Nm
(10
ft-lb)
Intake
air
temperature
(IAT)
sensor,
testing
and
replacing
The
intake
air
temperature
(IAT)
sensor
signal
is
usedasa
correction
factor
for
fuel
injection
and
ignition
timing
.
Thissen-
sor
is
mounted
in
the
intake
manifold
behind
the
throttle
posi-
tion
switch
.
See
Fig
.
28
.
Check
TPS
function
by
disconnecting
theharnessconnec-
1
.
Check
that
ECM
reference
voltage
is
reaching
IAT
sen-
tor
and
testing
continuity
across
the
terminalswhile
changing
sor
:
the
throttle
position
.
Resistance
test
values
are
listed
below
.
If
"
Disconnect
IAT
sensor
harness
connector
.
the
resuits
are
incorrect,
replace
the
throttle
position
sensor
.
"
Turn
ignition
keyon
.
See
Fig
.
29
.
"
Check
for
5
volts
between
supply
voltage
wire
of
har-
ness
connector
and
ground
.
NOTE-
"
Turn
ignition
key
off
.
The
throttle
position
sensor
is
not
adjustable
.
If
test
re-
sults
are
incorrect,
the
sensor
should
be
replaced
.
IAT
Sensor
Supply
Voltage
"
M50/S50US
engines
.
........
grey
wire
and
ground
FUEL
INJECTION
130-19
Fig
.
28
.
Intake
air
temperature
sensor
location
on
M50/S50US
engine
(arrow)
.
If
voltage
is
not
present
or
incorrect,
check
wiring
from
ECM
and
check
reference
voltage
signal
at
ECM
(pin
77)
.
See
Ta-
ble
i
or
Table
j
.
2
.
Check
IAT
sensor
resistance
:
"
With
harness
connector
disconnected,
check
resis-
tance
acrosssensor
terminals
.
Compare
tests
resuits
to
values
in
Table
f
given
earlier
.
"
If
IAT
sensor
fafs
thistest
it
is
faulty
and
should
be
re-
placed
.
3
.
If
no
faults
are
found,
reconnect
electrical
harness
.
Throttle
position
sensor
(TPS),
testing
and
replacing
The
throttle
position
sensor
(TPS)
is
mounted
on
the
side
of
the
throttle
housing
and
is
directly
connected
to
the
throttle
valve
shaft
.
The
ECM
sends
a
voltage
signal
to
the
potentiom-
eter-type
sensor
and
monitors
the
voltage
that
comes
back
.
BOSCH
DME
M3
.
1
AND
M32
.1
COMPONENT
TESTS
AND
REPAIRS