coolant temperature sensor BMW 318i 1997 E36 User Guide
[x] Cancel search | Manufacturer: BMW, Model Year: 1997, Model line: 318i, Model: BMW 318i 1997 E36Pages: 759
Page 168 of 759
130-
2
2
FUEL
INJECTION
Mass
air
flow
sensor,
replacing
1
.
Disconnect
harness
connector
and
intake
air
bootfrom
air
flow
sensor
.
See
Fig
.
32
.
Fig
.
32
.
To
detach
air
flow
sensor,
disconnect
harness
connector
(A)
;
3
.
Installation
is
reverse
of
removal
.
unclip
retainíng
clips
to
aír
filter
housing
(B)
;
andremove
large
hose
clamp
at
air
intake
bellows
(C)
.
M44
engine
with
traction
"
Use
a
new
copper
sealing
washer
when
installing
sen-
control
shown
.
sor
.
"
Replace
any
lost
coolant
.
2
.
Detachtwo
large
clipsat
air
filter
housing
and
work
air
flow
sensor
out
of
rubber
seal
in
filter
housing
.
Tightening
Torque
3
.
Installation
is
reverse
of
removal
.
"
Engine
coolant
temperature
"
For
ease
of
installation,
lubricate
large
rubber
seal
in
to
cylinder
head
.............
.
..
.
13
Nm
(10
ft-Ib)
air
filter
housing
with
silicone
lubricant
or
equivalent
.
"
No
adjustment
to
air
flow
sensor
is
possible
.
"
Carefully
check
that
all
hoses
and
seals
are
seated
Intake
air
temperature
(IAT)
sensor,
properly
.
replacing
Engine
coolant
temperature
(ECT)
sensor,
replacing
The
engine
coolant
temperature
(ECT)sensor
is
a
dual
temperature
sensor
.
One
circuít
provides
coolant
temperature
information
to
the
ECM
while
the
other
circuít
provides
coolant
temperature
information
to
the
instrument
cluster
.
WARNING
-
Do
not
replace
the
ECT
sensor
unless
the
engine
is
cold
.
Hot
coolant
can
scald
.
1
.
Disconnect
harness
connector
from
ECT
sensor
.
See
Fig
.
33
.
2
.
Unscrew
temperature
sensorfrom
cylinder
head
and
remove
BOSCH
DME
M5
.2
COMPONENT
REPLACEMENT
U1111
bis4a
Fig
.
33
.
M44
engine
coolant
temperature
(ECT)
sensor
located
above
oil
filter
(arrow)
.
The
intake
air
temperature
(IAT)
sensoron
cars
with
M44
engine
is
mounted
in
thetop
section
of
the
intake
air
filter
housing
.
See
Fig
.
34
.
1
.
Remove
electrical
harness
connector
from
IAT
sensor
.
2
.
Unclip
temperature
sensor
and
remove
from
air
filter
housing
.
3
.
Installation
is
reverse
of
removal
.
Throttle
position
sensor
(TPS),
replacing
The
throttle
position
sensor
is
located
on
the
side
of
the
throttle
housing
.
See
Fig
.
35
.
1
.
Unplug
harness
connector
from
sensor
.
Page 171 of 759
Mass
air
flow
sensor,
replacing
1
.
Disconnect
harness
connector
and
intake
air
boots
from
air
flow
sensor
.
See
Fig
.
37
.
Fig
.
37
.
Mass
air
flow
sensor
(arrow)
on
M52
engine
.
2
.
Installation
is
reverse
of
removal
.
"
No
adjustment
to
aír
flow
sensor
is
possible
.
"
Check
intake
hoses
for
cracks
and
vacuum
leaks
.
Engine
coolant
temperature(ECT)
sensor,
replacing
The
ECT
sensor
is
a
dual
temperature
sensor
.
One
circuit
provides
coolant
temperature
information
to
the
ECM
while
the
other
circuit
provides
coolant
temperature
information
to
the
instrument
cluster
.
1
.
Remove
left-side
top
engine
cover
.
4
.
Remove
sensor
.
5
.
Installation
is
reverse
of
removal
.
"
Replace
any
lost
coolant
.
0012703
"
Use
a
new
copper
sealing
washer
when
installing
new
Tightening
Torque
"
Engine
coolant
temperature
to
cylinder
head
.....
..
.
...
......
13
Nm
(10
ft-Ib)
FUEL
INJECTION
130-
25
0012704b
Fig
.
38
.
M52
engine
:
Engine
coolant
temperature
(ECT)
sensor
(A)
is
located
beneath
top
engine
cover
(8)
and
crankcase
vent
hose
(C)
.
Intake
air
temperature
(IAT)
sensor,
replacing
The
intake
air
temperature
(IAT)
sensor
for
the
M52/S52US
engine
is
mounted
on
the
bottom
of
the
intake
manifold
.
See
Fig
.
39
.
2
.
Unclip
crankcase
venting
hose
from
cylinder
head
cov-
er
.
See
Fig
.
38
.
Fig
.
39
.
M52/S52US
engine
:
Intake
air
temperaturesensor
location
in
bottom
of
intake
manifold(arrow)
.
Throttle
housing
shown
re
3
.
Under
intake
manifold,
disconnect
harness
connector
moved
.
fromsensor
.
1
.
Disconnect
intake
air
bootfrom
throttle
housing
.
Unbolt
throttle
housing
and
¡ay
aside
.
(It
is
not
necessary
to
disconnect
throttle
cable
or
electrical
harnessconnec-
tors
from
throttle
housing
.)
sensor
.
2
.
Remove
electrical
harness
connector
from
IAT
sensor
.
3
.
Unclip
temperature
sensor
and
remove
from
intake
manifold
.
4
.
Installation
is
reverse
of
removal
.
Use
a
new
gasket
at
the
throttle
housing
.
SIEMENS
MS
41
.1
COMPONENT
REPLACEMENT
Page 174 of 759
130-
2
8
FUEL
INJECTION
Tableh
.
ECM
Pin
Assignment-Bosch
DME
M1
.7
Pin
Signal
Componenttfunction
Signal
1
Output
Fuel
pump
relay
control
Fuel
pump
relay,
terminal
85
2
Not
used
3
Output
Cyl
.
2
and
cyl
.
4
fuel
injection
valve
control
Cyl
.
2
and
cyl
.
4
fuel
injection
valves
4
Not
used
5
Not
used
6
Ground
Ground,
fuel
injection
valveoutputstages
Ground
point
7
Not
used
8
Output
"Check
engine"
indicator
control
Instrument
cluster
9
Not
used
10
Not
used
11
Output
DKV
potentiometer
signal
Transmission
control
module
(EGS)
12
Input
Throttleposition
sensor
Throttleposition
Signal
13
Not
used
14
Input
Volume
air
flow
sensor
Volume
air
flow
sensor
(signal
ground)
15
Input
Cyl
.
1-2
knock
sensor
Cyl
.
1-2
knock
sensor
16
Input
Camshaft
position
sensor
(cylinder
identification)
Camshaft
position
sensor
(cylinder
identification)
17
Output
ti
measurement
signal
(fuel
consumption)
Instrument
cluster
18
Output
Intakeair
resonance
changeover
valve
(DISA)
Intake
air
resonance
changeover
valve
19
-
Not
used
20
Not
used
21
Not
used
22
Not
used
23
Not
used
24
Output
Cyl
.
3
ignition
coil
control
Cyl
.
3
ignition
coil
25
Output
Cyl
.
1
ignition
coil
control
Cyl
.
1
ignition
coil
26
Input
Battery
voltage
B
+junction
point
27
Output
Engine
control
module
relay
control
Engine
control
module
relay,
terminal
85
28
Ground
Ground
for
electronics
and
shielding
of
sensors
Ground
point
29
Output
Idle
speed
control
valve
control
Idle
speed
control
valve
30
Not
used
31
Not
used
32
Output
Cyl
.
1
and
cyl
.
3
fuel
injection
valve
control
Cyl
.
1
and
cyl
.
3
fuel
injection
valves
33
Not
used
34
Ground
Ground,
output
stages
(except
for
ignition
and
fuel
Ground
point
injection
valves)
35
Not
used
36
Output
Evaporative
emissionvalve
control
Evaporative
emission
valve
37
Output
Oxygen
sensor
heater
control
Oxygen
sensor
relay,
terminal
85
38
Not
used
39
Not
used
40
I
Not
used
41
I
Input
,
Volume
Air
Flow
sensor
Volume
air
flow
sensor
(voltage
varies
with
engine
load)
42
1
Input
1
Cyl
.
3-4
knock
sensor
1
Cyl
.
3-4
knock
sensor
43
Ground
Ground
for
sensors
Engine
coolant
temperature
sensor,
cyl
.
1-2
knock
sensor,
cyl
.
3-4
knock
sensor,
and
throttle
position
sensor
44
1
Input
1
Camshaft
position
sensor
(cylinder
identification)
1
Camshaft
position
sensor
(cylinder
identification)
ECM
PIN
ASSIGNMENTS
Page 175 of 759
Tableh
.
ECM
Pin
Assignment--Bosch
DME
M1
.7
Pin
1
Signal
1
Component/function
1
Signal
45
Notused
46
Notused
47
Notused
48
Output
A/C
compressor
cut-out
Compressor
control
relay,
terminal
85
49
Notused
50
Notused
51
Output
Cyl
.
4
ignition
coil
control
Cyl
.
4
ignition
coil
52
Output
Cyl
.
2
ignition
coil
control
Cyl
.
2
ignition
coil
53
Not
used
54
Input
Battery
voltage
from
engine
control
module
Engine
control
module
relay,
terminal
87a
55
Ground
Ground,
ignition
Ground
point
56
Input
Ignition
switch,
terminal
15
Ignition
switch,
terminal
15
57
Notused
58
Not
used
59
Output
Throttleposition
sensor
and
volume
air
flow
sensor
Reference
voltage
(5
VDC)
60
Input
Programming
voltage
Data
link
connector
61
Notused
62
Notused
63
Notused
64
Input
Ignition
timing
intervention
Transmission
control
module
(EGS)
65
Input
Drive
range
P/N
Automatic
transmission
range
switch
66
Notused
67
Input
Crankshaft
position
RPM
sensor
Crankshaft
position
RPM
sensor
68
Input
Crankshaft
position
RPM
sensor
Crankshaft
position
RPM
sensor
69
Notused
70
Input
Oxygen
sensor
signal
Heated
oxygen
sensor
71
Ground
Oxygen
sensor
signal
ground
Heated
oxygen
sensor
72
Notused
73
Input
Vehicle
speed
signal
Instrument
cluster
74
Output
Engine
speed
signal
Instrument
cluster
75
Not
used
76
Input
Volume
air
flow
sensor
Volume
air
flow
sensor
77
Input
Intake
air
temperature
sensor
(IAT)
Intake
air
temperature
sensor
(IAT)
78
Input
Engine
coolant
temperature
Engine
coolant
temperature
sensor
79
Notused
80
Not
used
81
Input
Drive-away
protection
signal
(code)
On-boardcomputer
82
Not
used
83
Notused
84
Not
used
85
Input
A/C
pressure
Pressure
switch
86
Input
A/C
switch
Integrated
climate
regulation
control
module
87
Output
RxD
diagnosisdata
line
Data
link
connector
88
Output-Input
TxD
diagnosisdata
line
l
Data
link
connector
FUEL
INJECTION
130-
2
9
ECM
PIN
ASSIGNMENTS
Page 177 of 759
Table
i
.
ECM
Pin
Assignment-Bosch
DME
M3
.1
Pin
Signal
Component/function
2
ignal
FUEL
INJECTION
130-
3
1
45
vacant
-
46
vacant
-
-
47
vacant
-
-
48
output
A/C
compressor
control
A/C
compressor
disabled
via
compressor
control
relay
49
vacant
-
-
50
output
Ignition
control
(terminal
1),cyl
.
n
o
.
4
Primary
signal,
ignition
coil
cyl
.
n
o
.
4
51
output
Ignition
control
(terminal
1),cyl
.
n
o
.
6
Primary
signal,
ignition
coil
cyl
.
no
.
6
52
output
Ignition
control
(terminal
1),cyl
.
n
o
.
5
Primary
signal,
ignitioncoil
cyl
.
no
.
5
53
vacant
-
54
input
Power
supply
Battery
voltage
(+)
from
main
relay
terminal
87
55
ground
Ground
Ground
for
ignition
control
56
input
Power
supply
(terminal
15)
Batteryvoltage
(+)
with
key
on
or
engine
running
57
vacant
-
-
58
vacant
-
-
59
output
Throttleposition
sensor
Throttleposition
sensorsupply
voltage
(5
VDC)
60
input
Data
link
connector
Programming
voltage
61
vacant
-
-
62
vacant
-
-
63
vacant
-
-
64
input
Ignition
timing
intervention
from
A/T
control
module
(only
active
during
gearshift)
65
input
Automatic
transmission
(A/T)
range
switch
Transmission
park
or
neutral
signal
66
vacant
-
-
67
input
Engine
speed/crankshaft
position
sensor
Crankshaft
position/rpm
(voltage
(VAC)
between
pins
67
and
68)
68
input
Engine
speed/crankshaft
position
sensor
Crankshaft
position/rpm
(voltage
(VAC)
between
pins
67
and
68)
69
vacant
-
-
70
input
Oxygen
sensor
Oxygen
sensor
signal
(0-1
VDC
fluctuating
with
engine
running)
71
ground
Oxygen
sensor
Oxygen
sensor
signal
ground
72
vacant
-
-
73
input
Road
speed
Road
speed
signal
from
instrument
cluster
74
output
Engine
speed
(TD)
Engine
speed
(TD)
signalto
instrument
cluster
75
vacant
-
-
76
vacant
-
-
77
input
Intakeair
temperature
(IAT)
sensor
Intake
air
temperature
(0-5
V,
temperaturedependent)
78
input
Engine
coolant
temperature
(ECT)
sensor
Engine
coolant
temperature
(0-5V,
temperature
dependent)
79
vacant
-
-
80
vacant
-
-
81
input
On-boardcomputer
Drive-away
protection
enable
82
vacant
-
-
83
vacant
-
-
84
vacant
-
-
85
input
A/C
pressure
switch
From
Integrated
climate
control
module
via
A/C
pressure
switch
86
input
A/C
compressor
on
From
Integrated
climate
control
module
87
input
Diagnostic
connector
(RxD)
Diagnostic
RxD
(receive)signal
to
pin
15
in
Data
link
connector
88
input/output
Diagnostic
connector
(TxD)
Diagnostic
TxD
(transmit)
signal
to
pin
20
in
Data
link
connector
ECM
PIN
ASSIGNMENTS
Page 179 of 759
Table
j.
ECM
Pin
Assignment-Bosch
DME
M3
.3
.1
Pin
~
Signal
1
Componentffunction
1
signal
FUEL
INJECTION
130-
33
45
ground
Ignition
circuit
shield
Ground
shieldfor
ignition
circuit
monitoring
46
output
Fuel
consumption
(KVA
signal)
To
instrument
cluster
47
output
Crankshaft
rpm
Engine
speed
(TD)
signal
to
instrument
cluster
48
output
A/C
compressor
control
A/C
compressor
relay
terminal
85
49
vacant
-
-
50
output
Ignition
coil
control,
cyl
.
1
Primary
signal,
ignition
coil
1
51
output
Ignition
coil
control,
cyl
.
2
Primary
signal,
ignition
coil
2
52
output
Ignition
coil
control,
cyl
.
3
Primary
signal,
ignition
coil
3
53
vacant
-
-
54
input
Power
supply
Battery
voltagefrom
main
relay
(terminal
87a)
55
ground
Ground
Ground
for
ignition
control
56
input
Power
supply
(terminal15)
Batteryvoltage
with
key
on
or
engine
running
57
input
Ignition
timing
intervention
From
A/T
control
module
58
vacant
-
-
59
output
Throttleposition
sensor
(TPS)
Voltage
supply
to
TPS
(5
VDC)
60
input
Programming
voltage
Data
link
connector
61
vacant
-
-
62
vacant
-
-
63
vacant
-
-
64
input
A/C
on
signal
From
integrated
climate
control
module
65
input
A/C
pressure
signal
From
integrated
climate
control
module
via
A/C
pressure
switch
66
input
On-board
computer
Drive-away
protection
enable
(starter
immobilization
relay)
67
vacant
-
-
68
vacant
-
-
69
input
Knock
sensor
#2
(cyl
.
4,5,
6)
Knock
sensor
#2
signal
70
input
Knock
sensor
#1
(cyl
.
1,2,
3)
Knock
sensor
#1
signal
71
ground
Ground
Ground
for
knock
sensors
and
shields
72
vacant
-
-
73
input
Throttleposition
sensor
(TPS)
Throttleposition
signal
74
vacant
-
75
vacant
-
-
76
vacant
-
77
input
Intakeair
temperatura
Intakeair
temperatura
sensor
(0-5
VDC)
78
input
Engine
coolant
temperature
Engine
coolant
temperature
sensor
(0-5
VDC)
79
vacant
-
80
vacant
-
-
81
input
Automatic
transmission
gear
positionlneutral
A/T
parkor
neutral
position
signal
safetyswitch
82
vacant
-
-
83
vacant
-
-
84
vacant
-
-
85
vacant
-
-
86
vacant
-
-
87
input
Diagnostic
connector
(RxD)
Diagnostic
RxD
(receive)
signal
to
pin
15
in
Data
link
connector
88
input/output
Diagnostic
connector
(TxD)
Diagnostic
TxD
(transmit)
signal
to
pin
20
in
Data
link
connector
ECM
PIN
ASSIGNMENTS
Page 181 of 759
Table
k
.
ECM
Pin
Assignment-Bosch
DME
M5
.2
(continued)
Pin
I
Signal
1
Componentltunction
1
Signal
45
I
output
I
Mass
air
flow
meter
I
Intake
airSignal
46
output
Oxygen
sensor
(monitoring
sensor)
Oxygen
sensor
control
47
not
used
-
48
not
used
-
49
output
Ignition
coil
control,
cyl
.
1
Primary
signal,
ignition
coil
1
50
output
Ignition
coil
control,
cyl
.
2
Primary
signal,
ignition
coil
2
51
not
used
-
52
not
used
-
53
input
Throttleposition
sensor
Throttleposition
Signal
54
input
Power
supply
Batteryvoltage
from
main
relay
(terminal
87)
55
ground
Ground
Ground
for
ECM
56
input
Power
supply
(terminal
15)
Battery
voltage
with
key
on
or
engine
running
57
output
Activate
cooling
fan
(man
.
trans
.)
control
Normal
speed
relay
58
not
used
-
-
59
not
used
-
-
60
input
Programming
voltage
Programming
voltage
via
data
link
connector,
pin
18
61
output
Evaporative
emissionvalve
Evaporative
emission
valve
control
62
vacant
-
-
63
output
Fuel
pump
relay
Fuel
pump
relay
control
64
not
used
-
65
not
used
-
-
66
not
used
-
-
67
not
used
-
-
68
input
Signal
above
80°C(man
.
tran
.)
Double
temperature
switch
69
input
Automatic
climate
control
Automatíc
climate
control
70
input
Knock
sensor
#1
(cyl
.
1,2)
Knock
sensor
#1
Signal
71
ground
Ground
Ground
for
analog
signals
and
knock
sensors
72
not
used
-
-
73
not
used
-
-
74
input
Engine
coolant
temperature
sensor
Engine
coolant
temperatura
Signal
75
not
used
-
-
76
not
used
-
-
77
output
Oxygen
sensor
(regulating
sensor)
Oxygen
sensor
control
78
input
Crankshaft/rpm
sensor
Crankshaft
position/rpmSignal
79
input
ABS
or
traction
control
ABS
or
AST
control
80
input
Engine
speed
Engine
speed
Signal
81
not
used
-
-
82
not
used
-
-
FUEL
INJECTION
130-
3
5
83
input
On-board
computar
From
On-boardcomputer
(terminal
4)
84
not
used
-
-
85
not
used
-
-
86
not
used
-
-
87
input
Diagnostic
connector
(RxD)
Diagnostic
RxD
(receive)signal
to
pin
15
in
Data
link
connector
88
output
I
Diagnostic
connector
(TxD)
Diagnostic
TxD
(transmit)
signal
to
pin
17in
Data
link
connector
ECM
PIN
ASSIGNMENTS
Page 182 of 759
130-
3
6
FUEL
INJECTION
Pin
1
Signal
1
Componentffunction
1
Signal
1
output
Ignition
coil
control,
cyl
.
2
Primary
signal,
ignition
coil
2
2
output
Ignition
coil
control,
cyl
.
4
Primary
signal,
ignitioncoil
4
3
output
Ignition
coil
control,
cyl
.
6
Primary
signal,
ignition
coil
6
4
ground
Ground
Ground
5
output
Fuel
injectorcontrol,
cyl
.
2
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
2
6
output
Fuel
injectorcontrol,
cyl
.
1
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
1
7
output
Mass
air
flow
meter
Mass
air
meter
signal
8
input
Mass
air
flow
meter
Mass
air
meter
signal
9
output
Instrument
cluster
Fuel
consumption
signal
10
output
Engine
coolant
temperature
(ECT)
sensor
ECT
signal
11
output
Fueltankpressure
sensor
Fueltankpressure
sensor
control
12
input
Throttleposition
sensor
(TPS)
Throttleposition
signal
13
-
14
input
Intake
air
temperature
(IAT)
sensor
Intake
air
temperature
signal
15
Traction
control
AST
module
16
input
Automatic
climate
control
Automatic
climate
control
17
18
input
Electronic
immobilizer
control
(EWS
II)
Electronic
immobilizer
control
(EWS
II)
module
19
Automatic
climate
control
Automatic
climate
control
20
-
Instrument
cluster
Instrument
cluster
21
output
Camshaft
actuator
(VANOS
solenoid)
control
Camshaft
actuator
(VANOS
solenoid),
switched
ground
22
output
Fuel
injectorcontrol,
cyl
.
3
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
3
23
Fuel
injectorcontrol,
cyl
.
6
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
6
24
Fuel
injectorcontrol,
cyl
.
4
Pulsed
ground
(injection
pulse
width
in
ms)
cyl
.
4
25
output
Oxygen
sensor
heater
control
Oxygen
sensor
heater
ground
26
input
Power
supply
(terminal
30)
Battery
voltage(B+)
at
all
times
27
output
Idle
speed
control
valve
Pulsed
ground-open
signal
(see
also
pin
53)
28
ground
Ground
Ground
29
output
Ignition
coil
control,
cyl
.
1
Primary
signal,
ignition
coíl
1
30
output
Ignition
coil
control,
cyl
.
3
Primary
signal,
ignition
coil
3
31
output
Ignition
coil
control,
cyl
.
5
Primary
signal,
ignition
coil
5
32
ground
Ground
Ground
33
output
Fuel
injector
control,
cyl
.
5
Pulsedground
(injection
pulsewidth
in
ms)
cyl
.
5
34
ground
Ground
Ground
35
output
Secondary
air
injection
Secondary
air
injection
pump
relay
control
36
output
Engine
speed
output
Engine
speed
signal
37
-
38
ground
Knock
sensor
Shielding
for
knock
sensors
39
output
Intake
air
temperature
sensor
(IAT
Sensor)
Voltagesupply
to
IAT
sensor
and
ECT
sensorEngine
coolant
temperature
(ECT)
sensor
40
output
Crankshaft
position
sensor
(Hall
effect)
Crankshaft
position
sensor
control
41
ground
Camshaft
position
(CMP)
sensor
Shielding
for
CMP
sensor
42
output
Throttle
position
sensor
(TPS)
TPS
ground
43
input
Camshaft
position/rpm
sensor
Camshaft
position/rpm
sensor
control
44
output
Throttle
position
sensor
(TPS)
Voltagesupply
to
TPS
(5
VDC)
45
Traction
control
AST
module
46
-
Instrument
cluster
Instrument
cluster
ECM
PIN
ASSIGNMENTS
Table
I.
ECM
Pin
Assignment-Siemens
DME
MS
41
.1
Page 195 of 759
170
Radiator
and
Cooling
System
GENERAL
.
.
.....
.
...
.
.
.
.
.
....
.
.
.
.
.
.
.
.170-1
Coolant
Pump
and
Thermostat
........
.
.
.
.
170-1
Radiator
and
Expansion
Tank
.........
.
...
170-1
Cooling
Fans
.
....
.
.
.
.
.
.
.
.
.
.....
.
......
170-2
Warnings
and
Cautions
.
.
.
.
.
.
.
.
.
.
.
.
...
.
.
.
170-2
TROUBLESHOOTING
...
.
.
.
...
.
.
.
.
.
.
.
.
.170-2
Cooling
System
Pressure
Test
...
.
.
.
.
.
.
.
.
.
170-3
Thermostat
Quick
Check
.
.
.
.
...
.
.
.
.
.
.
.
.
.
170-3
Temperature
Gauge
Quick
Check
.
.
.
.
.
.
.
.
.
170-3
Cooling
fan,
testing
.
.
.
.
........
.
.
.
.
.
.
.
.
.
170-4
COOLING
SYSTEM
SERVICE
.
.
.
.
.
.
.
.
.
.
170-5
Coolant,draining
and
filling
.
.
......
.
.
.
.
.
..
170-5
Cooling
system,
bleeding
(radiator
with
integral
expansion
tank)
.....
170-6
GENERAL
This
section
covers
repair
and
troubleshooting
information
for
the
engine
cooling
system
.
For
heater
core
and
related
heating
and
air
conditioning
components,
see640
Heating
and
Air
Conditioning
.
Coolant
Pump
and
Thermostat
A
centrifuga¡-type
coolant
pump
is
mounted
to
the
front
of
the
engíne
.
The
belt-driven
pump
circulates
coolant
through
the
system
whenever
the
engíne
is
running
.
A
thermostat
con-
trols
the
flow
of
coolant
into
the
radiator
.
When
the
engíne
is
cold
the
thermostat
is
closed
so
coolant
bypasses
the
radiator,
recirculating
from
the
engíne
directly
back
to
the
pump
.
When
the
engíne
reaches
operating
tem-
perature,
the
thermostat
opens
and
coolant
circulates
through
the
whole
system
including
the
radiator
.
Radiator
and
Expansion
Tank
The
radiator
is
a
crossflow
design
.
A
translucent
expansion
tank
provides
for
coolant
expansion
at
higher
temperatures
and
easy
monitoringof
the
coolant
leve¡
.
On
4-cylinder
modeis,
the
radiator
expansion
tank
is
integral
with
the
radiator
.
See
Fig
.
1
.
RADIATOR
AND
COOLING
SYSTEM
170-1
Belt-driven
cooling
fan,
replacing
.
.......
.
.
.
170-7
Electric
cooling
fan,
replacing
.
.
.
.....
.
.
.
.
.
170-8
Auxiliary
cooling
fan,
replacing
.
.
.....
.
.
.
.
.
170-8
Thermostat,
replacing
.
.
.
.
.
.
.
.
.
.....
.
.
.
.
.
170-9
Coolant
pump,
replacing
..........
.
.
.
.
.
.
170-10
RADIATOR
SERVICE
.....
.
......
.
.
.
.
.
.
170-11
Radiator,
removing
and
installing
....
.
.
.
.
.
.
170-11
TABLES
a
.
Coolant
Temperature
Sensor
Wire
Colors
...
.
..
.
.
170-3b
.
Auxiliary
Cooling
Fan
Switching
Temperatures
.:.
.170-4
c
.
Auxiliary
Cooling
Fan
Temperature
Switch
Tests
..
..
.
...
...
.
.............
.
..
.
.
170-5d
.
Cooling
System
Capacities
..............
..
.
.
.
170-6
A
.
Expansion
tank
C
.
Dualtemperature
fan
switch
B
.
Radiator
drain
screw
Fig
.
1
.
Radiator
assembly
with
integral
expansion
tank
(4-cylinder
engine)
.
On
6-cylinder
models,
a
standalone
expansion
tank
is
used
.
On
cars
with
automatic
transmission,
ATF
is
circulated
through
an
additional
heat
exchanger
(ATF
cooler)
.
GENERAL
Page 197 of 759
Cooling
System
Pressure
Test
If
the
engine
overheats
and
no
other
cooling
system
testsindicate
trouble,
the
radiator
may
have
some
pluggedpassag-
A
cooling
system
pressure
test
is
used
to
check
for
internal
es
that
are
restricting
coolant
flow
.
leaks
.
Some
of
the
common
sources
ofinternal
leaks
are
a
faulty
cylinder
head
gasket,
a
cracked
cylinder
head,
or
a
Temperature
Gauge
Quick
Check
cracked
cylinder
block
.
The
coolant
temperature
sensor
is
located
on
the
intake
To
doa
cooling
system
pressure
test,
a
special
pressure
manifold
(left)
side
of
the
cylinder
head,
under
the
intake
man-
tester
is
needed
.
ifold
runners
.
See
Fig
.
2
.
WARNING
-
At
normal
operating
temperature
-
the
cooling
sys-
tem
is
pressurized
.
Allow
the
system
to
cool
before
opening
.
Release
the
cap
slowly
to
allow
sale
re-
tease
of
pressure
.
With
the
engine
cold,instan
a
pressure
tester
to
the
expan-
sion
tank
.
Pressurize
thesystem
to
the
specification
listed
be-
low
.
Pressure
should
not
drop
more
than
0
.1
bar
(1
.45
psi)
for
at
leakt
two
minutes
.
If
the
pressure
drops
rapidly
and
there
is
no
sign
of
an
externa¡
leak,
the
cylinder
head
gasket
may
be
faulty
.
Considera
compression
test
as
described
in
100
En-
gine-General
.
The
screw-on
type
expansion
tank
cap
should
also
be
test-
ed
using
a
pressure
tester
and
the
correct
adapter
.
Cooling
System
Test
Pressure
"
Radiator
test
pressure
.........
.
1
.5
bar
(21
.75
psi)
"
Radiator
cap
test
pressure
..
.
........
2
bar
(29
psi)
CA
UTION-
Exceeding
the
speclfied
test
pressure
could
dam-
age
the
radiatoror
other
system
components
.
Carefully
inspect
the
radiator
cap
for
damage
.
Replace
a
faulty
cap
or
a
damaged
cap
gasket
.
Thermostat
Quick
Check
In
later
models,
the
ECT
sensor
and
the
gauge
sender
are
combined
into
one
sender
unit
.
For
wire
colors
refer
to
Table
a
.
To
check
if
the
thermostat
is
opening
and
coolant
is
circulat-
ing
through
the
radiator,
allow
a
cold
engine
to
reach
operat-
ing
temperature
(temperature
gauge
needieapproximately
centered)
.
Shut
off
engine
.
Feel
the
top
radiator
hose
.
If
the
hose
is
hot
to
the
touch,
the
coolant
is
probably
circulating
cor-
rectly
.
If
there
are
any
cool
areas
in
the
hose
or
radiator,
cool-
ant
flow
to
the
radiator
is
probably
restricted
.
Check
for
a
faulty
thermostat
or
aplugged
radiator
.
NOTE-
A
thermostat
that
is
stuck
open
will
cause
the
engine
to
warmup
slowly
and
run
belownormal
temperature
at
highway
speed
.
A
thermostat
that
is
stuck
closed
will
re-
strict
coolant
flow
to
the
radiator
and
cause
overheating
.
RADIATOR
AND
COOLING
SYSTEM
170-
3
U
.¡ig
.v
Fig
.
2
.
Temperature
gauge
sender
on
M44
engine
.
Temperature
gauge
sender
location
is
similar
on
al]
engines
.
In
early
models,
the
engine
coolant
temperature
(ECT)
sen-
sor
for
the
fuel
injection
and
the
coolant
temperature
gauge
sender
are
located
side
by
side
.
Table
a
.
Coolant
Temperature
Sensor
Wire
Colors
Function
Sensor
Terminal
Wire
colors
location
number
Two
sensors
:
Temperature
Rear
1
Brown/violet
gauge
sender
2
Brown/yellow
ECT
sensor
Front
1
Brown/red
2
Brown
or
Brown/black
One
sensor
:
Temperature
Dual
1
Brown/yellow
gauge
sender
sensor
2
Brown/violet
ECT
sensor
3
Brown/red
4
Brown/black
or
Grey/black
TROUBLESHOOTING