1998 JAGUAR X308 sensor

2. Release the hose, expansion tank to recovery tank.
3. Release the hose, expansion tank to radiator.
20. Fit blanking plugs to the pipes and the tank.

21. Remove the expansion tank from the mounting.
1. Disconnect the coolant level sensor connector.
2. Remove the nuts which secure the tank.

22. Remove the expansion tank from the vehicle.
1. It may be necessary to us e a pipe clamp to clamp the
bottom hose branch.
2. Release the pipe clip an d move it along the pipe.
3. Disconnect the tank from the bottom hose and remove it from the vehicle.
23. Empty any remaining coolant from the expansion tank into a
drain tray.
24. Remove the cloth from the engine and clean any spillage from
the engine bay.

25. Disconnect the radiator breather hose.
Release the Quick-Fit hose (radiator to expansion tank)
using 303 - 623, and disconnect the hose from the
radiator.
26. Remove the twin fan and motor assembly. Refer to Operation
26.25.12.

36. Disconnect the engine oi l pressure transmitter.
37. Remove the filler cap from the power steering reservoir.

38. Disconnect the hoses from the power steering pump.
Position a drain tray under the pump.
1. Release the high pressure hose union nut and drain the fluid.
2. Discard the O-ring seal an d fit blanking plugs to the
pipe and union.
3. Release the feed hose from the pump and fit blanking
plugs to the pipe and union.
Discard the fluid.

39. Release the Oxygen sensor multi-plugs from the mounting
bracket and disconnect the plugs.
40. Remove the four nuts, each side, which secure the downpipe
catalytic converters to the exhaust manifold.

2
. Reposition and secure the pipe clip.
3. Position the expansion tank to the left side enclosure
panel.

47
.
Fit the expansion tank securing nuts.
1. Connect the coolant level sensor connector.
2. Fit the nuts which secure the tank.

48
.
Connect the hoses (Quick Fit connections) to the expansion
tank.
Remove all blanking plug s
from the pipes and the
expansion tank.
1. Connect the hose, expansion tank to thermostat housing (coolant outlet pipe on supercharged
engines).
2. Connect the hose, expansion tank to recovery tank.
3. Connect the hose, expansion tank to radiator.

49
.
Fit the trim panels to the engine compartment.
1. Locate the centre trim panel.
2. Fit the left hand side enclosure panel.
50. Fit the intake tube / air flow meter / air cleaner cover
assembly.
1. Position the intake tube / air flow meter / air cleaner
cover assembly.
2. Fit a new rubber seal and po sition the air intake tube

A coola
nt outlet plastic pipe connects to the outlet port of ea
ch cylinder head to provide a common connection point for the
radiator top hose. It also incorporates the Engine Coolant Te mperature (ECT) sensor which provides a signal representing
coolant temperature at the cylinder heads. The outlet pipe has connections to supply the heater matrix and the bypass flow
to the thermostat housing. An in-groove ga sket, seals each of the outlet-to-cylinder head joints. An aluminium gasket seals
the ECT sensor to duct joint.
Coolant Outlet Duct - Supercharged

The coolant outlet duct on the supercharged engine performs exactly the same function as on the normally aspirated engine
and connects to the same ports on the engine. The main physical difference is that the thermostat housing has been
ItemDe
scription
1Bottom

Hose Connection
2The

rmostat Cover
3The

rmostat
4Coolan

t Outlet Duct
5B

reather Connection
6ECT Se

nsor
7Top Hose Conn

ection
8Bypa

ss to Water Pump
9Hea

ter Hose Connection

Whe r
e considered necessary, some hose conn
ections have an indication mark to ensure correct orientation of the hose when
being fitted.
All joints use spring-band clips, except small pipes on the bleed system joints - which use cobra clips. The heater feed and
return hoses use quick-connection unions.
Supply and return hoses for the heater are located between the cylinder banks.
A connection on the rear of the A-bank provides coolant supply for the electronic throttle and the EGR valve (where fitted).
The outlet from the electronic throttle connects to the return hose from the heater.
Cool
ant Header and Recovery Tanks
A recovery system comp
rising the header tank
and a recovery tank is fitted. The recove ry tank is located in front of the left
hand front wheel arch liner.
The header tank provides the cooling system filling point and carries the coolant level sensor. The pressure cap allows
controlled release of coolant to the re covery tank during normal operation.
The recovery tank accommodates the expansion of the system coolant during normal operation. On engine cool-down, the
coolant contracts and is returned to the main system.
Coo lin
g Fans
The two
rad
iator cooling fans are mounted in
a cowl assembly within the cooling module.
The fans are controlled by the ECM dependent on the demand fr om the cooling system (temperature) or the air conditioning
ItemDescrip
tion
1EGR
E
ngines
2Non
-
EGR Engines
3Hea
ter Connections

s
ystem (pressure).
Outputs from the ECM control the radiator fans control module, located behind the left hand side of the bumper, to operate
the fans in the series mode (slow), paralle l mode (Fast) or Off modes. Hysteresis in the temperature and pressure switching
values prevents 'hun ting' between modes.
Under hot operating conditions, the fans may continue to operat e for some time after the engine has been switched off, but
will stop automatically when the coolant te mperature has been sufficiently reduced.
Engine Coolant Temperature Sensor (ECT) and ECM

The engine coolant temperature (ECT) sensor is located in the coolant outlet pipe and reacts to engine coolant temperature
changes, providing an input to the Engine Control Module (ECM). The sensor has a negative te mperature coefficient so that
the sensor resistance decrea ses as temperature rises.
Temperature / Resistance Relationship Graph

T
emperature / Resistance
Relationship Table

Engi
ne Coolant Temperature Sensor (ECT) - Circuit Diagram

Intercooler Pump Relay - Circuit Diagram
T emper
ature (°C)
No
mi
nal Resistance (kOHM)
-2
015 .0
4
05.7
4
202.45
401.15
600.
584
800.3
2
1000.
184
ItemPar
t
Number
De
scrip
tion
1—Eng
i
ne Coolant Temperature (ECT) Sensor
2—Eng
i
ne to EMS Harness Connector
3—EMS Con
trol Modu
le

Engine Cooling - Engine Cooling
Diagn
osis and Testing
Related Faults / Codes

Adaptive
Fue
ling
Sym
p
tom Chart
Sy
m
ptom Chart
S
p
ecial Tool(s)

D
i
gital multimeter

Generi
c scan tool
Conditi
on
Possib
l
e Source
Acti
o
n
D
T
C P0171 System too lean bank
1 (A)
D T
C P0174 System too lean bank
2 (B)
Fuel delivery blockage Fu
el delivery pressure (low)
F
a
ulty injector (blocked)
Ai
r i
ntake system leak
F
u
el injector electrical fault
ECT sensor
faul
t
MAFM sensor fault IAT se
nsor fault

Thro
tt
le position sensor
fault
Mec hanica
l check
Mec
hanica
l check
Mec
hanica
l check
Mec
hanica
l check
Go t
o DTC P020
1 to 0208
Go t
o
DTC P0116 to 0118, P0125
Go t
o
DTC P0101 to 0103, P1104
Go t
o DTC P011
1 to 0113
Go t
o
DTC P0121 to 0123, P0222,
P0223
D T
C P0172 System too rich bank
1 (A)
D T
C P0175 System too rich bank
2 (B)
F u
el delivery pressure
(high)
F a
ulty injector (leaking)
F
u
el injector continuously
open
Ai r i
ntake system restricted

Fu
el injector electrical fault
ECT sensor
faul
t
MAFM sensor fault IAT sensor fault


Thrott

le position sensor
fault
Mec hanica
l check
Mec
hanica
l check
Mec
hanica
l check
Mec
hanica
l check
Go t
o DTC P020
1 to P0208
Go t
o
DTC P0116 to P0118, P0125
Go t
o
DTC P0101 to P0103, P1104
Go t
o DTC P011
1 to P0113
Go t
o
DTC P0121 to P0123, P0222,
P0223
Sy m
ptom
Possib
l
e Sources
Acti
o
n
D
T
C P0116 ECT circuit range / performance problem
Thermostat
Coo
l
ant level / contamination
Sensor out of range
Harness open circuit
Connector loose or corroded
*
*
*
*
*
GO to Pinpoint

Test A

*
D
T
C P0125 Insufficient coolant temperature for closed
loop fuel control
Thermostat
Coo l
ant level / contamination
Sensor out of range
Harness open circuit
Connector loose or corroded
*
*
*
*
*
GO to Pinpoint

Test A

*
D
T
C P0117 ECT circuit low input
Sensor o
p
en circuit
Harness open circuit
Harness short
*
*
*
GO to Pinpoint

Test B

*