1998 JAGUAR X308 temperature sensor

Pinpoint test
A: P0116, P0125
Connector
loose or corroded
*
D
TC P0118 ECT circuit high input
Sensor short
Harness open circui

t
Harness short
Connector loose or corroded
*
*
*
*
GO to Pinpoint

Test C
*
D
TC P1474 Intercooler coolant pump relay malfunction
Intercooler pump relay
failure
Intercooler pump relay to ECM drive circuit
fault Intercooler pump relay coil ground circuit
fault Harness fault
Connector loose or corroded
Connector pins(s) bent or tracking between
connections ECM power supply fault
*
*
*
*
*
*
*
GO to Pinpoint

Test D
*
P
INPOINT TEST A : P0116, P0125
T
EST CONDITIONS
D
ETAILS/RESULTS/ACTIONS
A1

: RETRIEVE DTCS
•

NOTE: Battery and or ECM disconnection prior to scanning wi
ll erase all data, ensure that the correct DTC is present.
Conne
ct the scan tool
1
Have the DTC(s) and fr

eeze
frame data been recorded?
Yes GO to A2
A2: ENGINE
COOLANT SYSTEM CHECK
•

NOTE: Do not use the instrument display, if th
e ECT has failed this will not operate correctly.
Chec
k engine temperature rise using a thermocouple or
similar device.
1
Engine
temperature increasing?
Yes GO to A3
No Check coolant level
Check coolant for contamination
Check/test thermostat

A3: CHECK ECT SE
NSOR RANGE
All
o
w the engine to achieve any noted temperature within

the specified range, refer to temperature / resistance
relationship table or graph
1
I g
nition switch to position 0
2
D
i
sconnect PI004
Re
ar
of top hose
3
Meas
ure t
he resistance between sensor pins 1 and 2.
4
Tem
p
erature / resistance relationship OK?
Yes GO to A4
No Remove sensor and check temperature / resistance
relationship for 3 different temperatures. Renew as
required and test the syst em for normal operation.
A4: CHECK
HARNESS
CONTINUITY

Engine Cooling - Coolant Outlet Pipe

Re
moval and Installation
Remov

al
Installation

1.
O
pen the engine compartment and fit paintwork protection
sheets.
2. Drain the radiator. Refer to Ge neral Procedures. Retain the
coolant drain tray in position to catch any spillage when
removing the outlet pipe.

3. Di
sconnect the hoses and multi-plug from the coolant outlet
pipe.
1. Release and reposition th e hose clip, and disconnect
the top hose.
2. Release and reposition th e hose clip, and disconnect
the heater hose.
3. Disconnect the multi-plug from the temperature sensor and unscrew the sens or from the outlet pipe.
4. Release and reposition the hose clip along the bypass
hose.

4. R
emove the coolant outlet pipe.
1. Remove the four bolts which secure the outlet pipe.
2. Remove the outlet pipe from the bypass hose and
from the cylinder heads.
5. Remove and discard the sealing rings from the outlet pipe
grooves.
1. Installation is the reverse of the remova l procedure. Use new
sealing rings on the coolant outlet pipe.
2. Tighten the coolant outlet pipe bolts to 10-14 Nm If replacing
the coolant temperature sensor, tighten to 15-19 Nm.
3. Refill the cooling system as de scribed in General Procedures.

Engine Cooling - Coolant Outlet Pipe
Remo
val and Installation
Remov
a
l
1.
Op
en the engine compartment and fit paintwork protection
sheets.
2. Drain the radiator. Refer to Ge neral Procedures. Retain the
coolant drain tray in position to catch any spillage when
removing the outlet pipe.

3. Disc onne
ct the top hose and br
eather pipe from the coolant
outlet pipe.
1. Release and reposition th e hose clip, and disconnect
the top hose.
2. Release and disconnect the breather pipe quick fit connector.
3. Disconnect the multi-plug from the temperature sensor and unscrew the sens or from the outlet pipe.
4. Release and reposition the hose clip along the bypass
hose.

4. Disc
onnect the bottom hose
from the thermostat housing.
1. Release and reposition th e hose clip along the hose.
2. Disconnect the bottom hose.

5. Disc
onnect the coolant outlet pipe from the cylinder heads.
1. Remove the four bolts which secure the outlet pipe.
2. Remove the outlet pipe from the bypass hose and
from the cylinder heads (still connected to the
heater hose).
6. Release and reposition the clip which secures the heater hose
to the outlet pipe and disconnect the hose. Remove the outlet
pipe.
7. Remove the thermostat from the outlet pipe.
1. Remove the three bolts which secure the thermostat cover to the outlet pipe.
2. Remove the thermostat cover, the thermostat and
the seal from the outlet pipe. Discard the seal.

I
nstallation



8.
Remove an
d discard the sealing
rings from the outlet pipe
grooves.
1. Installation is th e reverse of the re moval procedure.
Use new
sealing rings on th
e coolant outlet pipe and
thermostat housing.
The t
hermostat ball valve must
locate in the recess in the
cover.
2. Tighten the coolant outlet pipe bolts to 8-12 Nm. If replacing
the coolant temperature sensor, tighten to 15-19 Nm.
3. Refill the cooling system as de scribed in General Procedures.

CAUTI
ON: When probing connectors to take
measurements in the course of the pinpoint tests, use the adaptor kit,
part number 3548-1358-00.
• NOTE: When performing electrical voltag e or resistance tests, always use a digital multimeter (DMM) accurate to 3
decimal places, and with an up-t o-date calibration certificate. When testing resistance, always take the resistance of the
DMM leads into account.
• NOTE: Check and rectify basic faults before beginning diagnostic ro utines involving pinpoint tests.
Sy
mptom Chart
Sy

mptom
Possib
le source
Acti
on
Engine

cranks, but does not fire
Secu
rity system /Immobiliser
engaged
Thr
ottle contaminated
Harness damage


F

uel pump relay
Fue

l system
R

efer to service action S491

Contact dealer techn
ical
support for information
on security system. Chec k bulletins for throttle
cleaning procedure. For fuel pump relay circuit
tests, GO to Pinpoint Test E.
.
Check fuel pressure,


REFER to Section 310
-00
Fuel System
- Gen
eral
Informati

on
.
Chec
k for associated DTCs
. Check service actions.
Engine
cranks and fires, but will
not start
F
uel pump relay
Thr

ottle contaminated
Purge

valve
Fue

l pump
Engine coolan

t temperature
(ECT) sensor
Spark plugs
fouled
Ignition coil

failure(s)
Check f

or water ingress into
spark plug wells
HT sho
rt to ground (tracking)
check rubber boots for cracks/damage
Cyl
inder compression loss
(short-term. Refer to bulletin;
303-52)
R
efer to service action S491

F
or fuel pump relay tests,
GO to Pinpoint Test E.
.
Check bull
etins for throttle cleaning procedure. For

evaporative emissions tests,
REFER to Section 303
-1
3 Evaporative Emissions
. Chec

k fuel pressure,
REFER to Section 310
-00
Fuel System
- Ge
neral
Informati

on
.
F
or ECT sensor circuit tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
For ign
ition system,
REFER to Section 303
-07
Engine Ignition
.
Check bulletins an d service
actions.
D

ifficult to start cold
Roc
hester valve
Batt

ery
Thr

ottle contaminated
Fue

l pump
Engine coolan

t temperature
(ECT) sensor
Purge
valve
Cyl

inder compression loss
(short-term. Refer to bulletin;
303-52)
Blocked part-load breather (
service action S474)
R

efer to service action S491

F
or rochester valve tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
F
or battery information,
REFER to Section 414
-0
1 Battery, Mounting and
Cables.
Check bull
etins for throttle cleaning procedure.
Check fuel pressure,
REFER to Section 310
-00
Fuel System
- Ge
neral
Informati

on
.
F
or ECT sensor circuit tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
For evaporat
ive emissions tests,
REFER to Section 303
-1
3 Evaporative Emissions
. Check bulletins an

d
service actions.
D
ifficult to start hot
Roc
hester valve
Purge

valve
Thr

ottle contaminated
Fue

l pump
Engine coolan

t temperature
(ECT) sensor
Blocked part-load breather (
service action S474)
Injec

tor leak
F
or Rochester
valve test,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
Fo
r injector leak test, REFER to technical service
bulletin, 303-39. Check fuel pressure, For evaporative emissions components,
REFER to Section 303
-1
3 Evaporative Emissions
. F

or ECT sensor tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls. D

ifficult to start after hot soak
(vehicle standing after engine has
reached operating temperature)
Roc
hester valve
Thr

ottle contaminated
Purge

valve
Fue

l pump
Engine coolan

t temperature

(ECT) se
nsor
Blocked part-load breather
(s
ervice action S474)
Injec
t
or leak
Engine stalls
soon
after start
F
u
el pump relay
ECM relay Thr
o
ttle contaminated
CMP/CKP sen
s
or
synchronization malfunction
Harness Fuel
pump
MAF
s
ensor malfunction
Engine coolan
t
temperature
(ECT) sensor
Fue l
lines
Air leakage Fu

el pressure regulator
F
o
r fuel pump relay tests,
GO to Pinpoint Test E.
.
F or ECM
relay tests,
REFER to Section 303
-14 Elec tronic En
gine
Controls.
Check bull etins for throttl
e cleaning procedure. For

CMP/CKP sensor tests,
REFER to Section 303
-14 Elec tronic En
gine
Controls.
Chec k fu
el pressure,
REFER to Section 310
-00 Fu
el System
- Ge
n
eral
Informati
o
n
.
F or MAF sensor and
ECT sensor tests,
REFER to Section 303
-14 Electronic En
gine
Controls.
For fuel l
ine information,
REFER to Section 310
-01
Fuel Tank and Lines
.
F or i
ntake system information,
REFER to Section 303
-1 2
Intake Air Distribution
and F
ilt
ering
.
F o
r fuel pressure regulato
r check, GO to Pinpoint
Test D.
.
Engine h e
sitates/poor
acceleration
Fue l
pump
Exhaus
t gas
recirculation
(EGR)
Air leakage Stop lamp swi t
ch
Throttl
e
sensors
Throttl
e
motor
Spark plugs

fouled
Check f
o
r water ingress into
spark plug wells
Ignition coil fail
ure(s)
HT sho
rt to ground (tracking)
check rubber
boots for
cracks/damage
ECM failu r
e
Chec
k fu
el pressure,
REFER to Section 310
-00 Fu
el System
- Ge
n
eral
Informati
o
n
.
F o
r EGR information,
REFER to Section 303
-08 En gin
e Emission
Control.
F or i
ntake system information,
REFER to Section 303
-1 2
Intake Air Distribution
and F
ilt
ering
.
F or stop l
amp switch in
formation, refer to the
wiring diagrams. For throttle position sensor and throttle motor relay tests,
REFER to Section 303
-14 Elec tronic En
gine
Controls.
For ign i
tion system,
REFER to Section 303
-07 En
gine Ignition
.
Contact dealer techn i
cal
support for advice on
possible ECM failure.
Engine ba ckfiresFuel
pump
Air leakage MAF s
e
nsor
HO2 sensors Spark plugs
Check fo
r water ingress into
spark plug wells
HT short to ground (tracking) check rubber
boots for
cracks/damage
Ignition coil fail
ure(s)
Chec
k fu
el pressure,
REFER to Section 310
-00 Fu
el System
- Ge
n
eral
Informati
o
n
.
F or i
ntake system information,
REFER to Section 303
-1 2
Intake Air Distribution
and F
ilt
ering
.
For MAF and HO2
sensor circuit tests,
REFER to Section 303
-14 Electronic En
gine
Controls.
For igni
tion system,
REFER to Section 303
-07 En
gine Ignition
.
Engine
s
urges
Air leakage Fue
l
pump
Stop lamp swi
t
ch
MAF s
e
nsor
Harness Throttl
e
sensors
Throttl
e
motor
Spark plugs
Check fo
r water ingress into
spark plug wells
HT sho rt to ground (tracking)
check rubber
boots for
cracks/damage
ECM failu r
e
F
or i
ntake system information,
REFER to Section 303
-1 2
Intake Air Distribution
and F
ilt
ering
.
Chec k fu
el pressure,
REFER to Section 310
-00 Fu
el System
- Gen
e
ral
Informati
o
n
.
F or stop l
amp switch in
formation, refer to the
wiring diagrams. For MAF se nsor, throttle position
sensor and throttle motor relay tests,
REFER to Section 303
-14 Elec tronic En
gine
Controls.
For ign i
tion system,
REFER to Section 303
-07 En
gine Ignition
.
Contact dealer techn i
cal
support for advice on
possible ECM failure.

• NO
TE: When performing electrical voltag
e or resistance tests, always use a digital multimeter (DMM) accurate to 3
decimal places, and with an up-t o-date calibration certificate. When testing resistance, always take the resistance of the
DMM leads into account.
• NOTE: Check and rectify basic faults before beginning diagnostic ro utines involving pinpoint tests.
Sym
ptom Chart
Sy
m
ptom
Possib
l
e source
Acti
o
n
Engine
cranks, but does
not fire
Secu
rit
y system /Immobiliser
engaged
Harness Fue l
system
ECM fault

Contact deal er techni
cal support for
information on security system. Check fuel
system pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For ECM tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
Engine cranks and
fi
res, but will not
start
Fu
el pump relay
Fuel

pump
Cyl
i
nder compression loss
(short-term. Refer to bulletin; 303-52)
Engine coolan t
temperature
(ECT) sensor
Spark plugs fouled, gapp
ed
incorrectly
Ignition coil fail
ure(s)
Check f
o
r water ingress into
spark plug wells
HT sho rt to ground (tracking)
check rubber
boots for
cracks/damage
Fo
r fuel pump relay tests,
REFER to: Fuel Charging and Controls
(303
-04

Fuel Charging and Controls, Diagnosis and Testing).
Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For compression loss, REFER to the technical service bulletins. For ECT sensor tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For spark plug tests, GO to Pinpoint Test B.
.
For ign i
tion system tests, GO to Pinpoint Test
A.
.
Diff
icult to start cold
Batt
ery Fuel
pump
Cyl
i
nder compression loss
(short-term. Refer to bulletin; 303-52)
Spark plugs fouled, gapp
ed
incorrectly
F o
r battery information,
REFER to: Battery and Cables
(414
-01 Battery,

Mounting and Cables, Description and Operation).
Check fuel pressure.
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For compression loss, REFER to the technical service bulletins. For spark plug tests, GO to
Pinpoint Test B.
. For ig
nition system tests, GO
to Pinpoint Test A.
.
Diff
icult to start hot
Roc
h
ester valve
Injec
t
or leak
Purge
val
ve
Fue
l
pump
Engine coolan
t
temperature
(ECT) sensor
F or R
ochester
valve test,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For injector leak test, REFER to technical
service bulletins. Check fuel pressure. For evaporative emissions components,
REFER to: Evaporative Emissions
(303
-13
Evaporative Emissions, Diagnosis and Testing).
For ECT sensor tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
D iff
icult to start after hot soak
(vehicle standing after engine has reached operating temperature)
Roc h
ester valve
Injec
t
or leak
Purge
val
ve
Fue
l
pump
Engine coolan
t
temperature
(ECT) sensor
F or R
ochester
valve test,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For injector leak test, REFER to technical service bulletins. Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).