1998 JAGUAR X308 heater

Engine Cooling - Cooling System Draining and Vacuum Filling
Gene
ral Procedures
WARNING: To avoid having scalding ho t coolant or steam blowing out of the cooling system, use extreme care when
removing the coolant pressure cap from a hot cooling system. Wait until the engine has cooled, then wrap a thick cloth
around the coolant pressure cap and turn it slowly until the pressure begins to release. Step ba ck while the pressure is
released from the system. When certain al l the pressure has been released (still with a cloth) turn and remove the coolant
pressure cap from the coolant expansion tank. Failure to fo llow these instructions may result in personal injury.
• CAUTIONS:
The engine cooling syst em must be maintained with the correct concentration and type of anti-freeze solution to
prevent corrosion and frost damage. Failure to follow th is instruction may result in damage to the vehicle.
Engine coolant will damage the paint finished surfaces. If spilt, immediately remove the coolant and clean the area
with water.
• NOTE: Vehicles fitted with supercharged engines shown, V8 NA engines similar.
All vehicles
1. Set
the heater controls to maximum HOT.

2. WARN
ING: Relieve the cooling system pressure by
unscrewing the coolant pressure cap. Failure to follow this
instruction may result in personal injury.
Remove the coolant expans ion tank pressure cap.
3. Raise a
nd support the vehicle.

4. NOTE : Remov
e and discard the
radiator drain plug seal.
Drain the coolant into a suitable container.
Remove the radiato
r drain plug.
5. CAUTION: Do not over tighten the drain plug. Failure to
follow this instruction may result in damage to the vehicle.
• NOTE: Install a new radiator drain plug seal.
Install the coolant drain plug.

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.

P0122Throttle
position (TP) sensor 1 low
voltage
TP se ns
or to ECM sensing circuit 1
(TP sensor pin 3) open circuit or
high resistance
TP sensor fail
ure
F
o
r TP sensor circ
uit tests,GO to
Pinpoint Test D.
, and GO
to Pinpoint
Test K.
.
P0123Throttl e
position (TP) sensor 1
high voltage
TP se ns
or to ECM sensing circuit 1
(TP sensor pin 3) short circuit to
high voltage
TP sensor fail
ure
F
o
r TP sensor circ
uit tests,GO to
Pinpoint Test D.
, and GO
to Pinpoint
Test K.
.
P0125En
gine coolant temperature (ECT)
sensor response (for closed loop
fuel control)
Low/contaminated coolant Therm o
stat failure
ECT se
ns
or to ECM sensing circuit
high resistance, open circuit or
short circuit to high voltage
Che c
k coolant level and condition.
Check thermostat function. For ECT
sensor circuit tests,GO to Pinpoint
Test C.
.
P0131Right -
hand H02S sense circuit low
voltage
H02 S
disconnected
H0
2S to
ECM wiring open circuit
H0
2S short ci
rcuit to ground
H0
2S fail
ure
F
or R
ight-hand HO2S circuit tests,GO
to Pinpoint Test E.
.
P0132Right-
hand H02S sense circuit
high voltage
H02 S
sensing circuit short circuit to
high voltage
H0 2S groun
d braided shield open
circuit
H0 2S fail
ure
F
or R
ight-hand HO2S circuit tests,GO
to Pinpoint Test E.
.
P0133Right-
hand H02S sense circuit
slow response
Engine m
isfire
H02
S
disconnected
H0
2S mechanical damage

H0
2S to
ECM wiring intermittent
open circuit
H02 S
sensing circuit short circuit to
high voltage
H02S short ci
rcuit to ground
H02S groun

d braided shield open
circuit
H0 2S heater circuit faul
t
Exhaus
t leak

Low e
x
haust temperature
Injector fl
ow parti
ally blocked
Catal
y
st efficiency decrease
H0
2S fail
ure
Chec
k for 'en
gine misfire detected'
DTCs. For HO2S circuit tests,GO to
Pinpoint Test E.
.G
O to Pinpoint Test
F.
. Check for exhaust leaks,
REF
ER to Section 309
-00
Ex
haust
Sy
ste
m
.
Chec k inje
ctors,
REFER to Section 303
-04 Fu
el
Charging and Cont

rols
.
P0135Right
-
hand H02S heater circuit
malfunction
H02 S
disconnected
H0
2S h
eater power supply open
circuit
H0 2S heater to ECM wi
ring short
circuit or open circuit
H0 2S heater fai
lure
F
o
r right-hand HO2S heater circuit
tests,GO to Pinpoint Test F.
.
P0137Right-
hand catalyst monitor
sensor sense circuit low voltage
Catal y
st monitor sensor
disconnected
Catal y
st monitor sensor to ECM
wiring open circuit
Catal y
st monitor sensor short
circuit to ground
Cat a
lyst monitor sensor failure
F
or ri
ght-hand catalyst monitor sensor

circuit tests,GO to Pinpoint Test G.
.
P0138Right -
hand catalyst monitor
sensor sense circuit high voltage
Catal y
st monitor sensor sensing
circuit short circuit to high voltage
Catalyst
monitor sensor ground
braided shield open circuit
Cata
lyst monitor sensor failure
F
or ri
ght-hand catalyst monitor sensor

circuit tests,GO to Pinpoint Test G.
.
P0140Right -
hand catalyst monitor
sensor sense circuit no activity
Catal y
st monitor sensor
disconnected
Catal y
st monitor sensor
mechanical damage
Catal y
st monitor sensor to ECM
wiring open circuit
Catal y
st monitor sensor sensing
circuit short circuit to high voltage
Cataly
st monitor sensor short
circuit to ground
Catalyst
monitor sensor ground
braided shield open circuit
F or ri
ght-hand catalyst monitor sensor

circuit tests, GO to Pinpoint Test G.
.
Check f o
r exhaust leaks,
REFER to Section 309
-00 Ex
haust
Sy
ste
m
.
Chec k inje
ctors,
REFER to Section 303
-04 Fu
el
Charging and Con
t
rols
.

Exhaus
t leak
Low e

xhaust temperature
Cat

alyst monitor sensor failure
P0151Le

ft-hand H02S sense circuit low
voltage
H02
S disconnected
H0

2S to ECM wiring open circuit
H0

2S short circuit to ground
H0

2S failure
F
or left-hand HO2S circuit tests, GO
to Pinpoint Test H.
.
P0152Le
ft-hand H02S sense circuit high
voltage
H02
S sensing circuit short circuit to
high voltage
H0
2S ground braided shield open
circuit
H0
2S failure
F
or left-hand HO2S circuit tests,GO to
Pinpoint Test H.
.
P0153Le
ft-hand H02S sense circuit slow
response
Engine
misfire
H02

S disconnected
H0

2S mechanical damage
H0

2S to ECM wiring intermittent
open circuit
H02
S sensing circuit short circuit to
high voltage
H0
2S short circuit to ground
H0

2S ground braided shield open
circuit
H0
2S heater circuit fault
Exhaus

t leak
Low e

xhaust temperature
Injector fl

ow partially blocked
Catal

yst efficiency decrease
H0

2S failure
Chec
k for 'engine misfire detected'
DTCs. For HO2S circ uit tests, GO to
Pinpoint Test H.
. Check for exhaust
leak
s,
REFER to Section 309
-00
Exhaust
Sy

stem
.
Chec
k injectors,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P0155Left-hand H02S heater

circuit
malfunction
H02
S disconnected
H0

2S heater power supply open
circuit
H0
2S heater to ECM wiring short
circuit or open circuit
H0
2S heater failure
F
or left-hand HO2S heater circuit
tests,GO to Pinpoint Test I.
.
P0157Le
ft-hand catalyst monitor sensor
sense circuit low voltage
Catal
yst monitor sensor
disconnected
Catal
yst monitor sensor to ECM
wiring open circuit
Catal
yst monitor sensor short
circuit to ground
Cat
alyst monitor sensor failure
F
or left-hand catalyst monitor sensor
circuit tests,GO to Pinpoint Test J.
.
P0158Le
ft-hand catalyst monitor sensor
sense circuit high voltage
Catal
yst monitor sensor sensing
circuit short circuit to high voltage
Catalyst
monitor sensor ground
braided shield open circuit
Cat
alyst monitor sensor failure
F
or left-hand catalyst monitor sensor
circuit tests,GO to Pinpoint Test J.
.
P0160Le
ft-hand catalyst monitor sensor
sense circuit no activity
Catal
yst monitor sensor
disconnected
Catal
yst monitor sensor
mechanical damage
Catal
yst monitor sensor to ECM
wiring open circuit
Catal
yst monitor sensor sensing
circuit short circuit to high voltage
Catal
yst monitor sensor short
circuit to ground
Catalyst
monitor sensor ground
braided shield open circuit
Exhaus
t leak
Low e

xhaust temperature
Cat

alyst monitor sensor failure
F
or left-hand catalyst monitor sensor
circuit tests,GO to Pinpoint Test J.
.
Check f
or exhaust leaks,
REFER to Section 309
-00
Exhaust
Sy

stem
.
P0171Right

-hand cylinders combustion
too lean
Air
intake leak between MAF senso
r and th

rottle
F

uel filter system blockage
F

uel injector blockage
F

uel pressure regulator failure (low

fuel pressure)
Low f
uel pump output
Check ai
r intake system for leaks,
REFER to Section 303
-1
2 Intake Air
Distribu

tion and Filtering
.
Check the fuel fi
lter,
REFER to Section 310
-01
Fuel Tank
and Lines.
Chec
k the fuel injectors and fuel

KS fail
ure
P0335Cranksh
a
ft positi
on (CKP) sensor
circuit malfunction
CK P
sensor disconnected
CKP sensor air gap
i
n
correct/foreign matter on face
CKP sensor sen
s
ing circuit open
circuit, short circuit to ground,
short circuit to high voltage
CKP s e
nsor failure
F
or CKP sensor circ ui
t tests,GO to
Pinpoint Test N.
.
P0340Camshaft position
(CMP) sensor
circuit malfunction
CM P
sensor disconnected
CMP sensor air gap
i
n
correct/foreign matter on face
CMP sensor sen
s
ing circuit open
circuit, short circuit to ground,
short circuit to high voltage
CMP s e
nsor failure
F
or CMP sensor circ ui
t tests,GO to
Pinpoint Test O.
.
P0351Igniti
on coil primary/secondary
circuit malfunction, cyl 1
ECM to ignit
ion module primary
circuit open circuit, short circuit to
ground, high resistance
Igniti
on module to ignition coil
primary circuit open circuit, short
circuit to ground, high resistance
Ignition modu le
ground circuit
open circuit, hi gh resistance
Ignition coil fail
ure
Ignition modul
e
failure
F
o
r ignition circuit tests,
REFER to Section 303
-07 En
gine
Ignition. P0352Ignit
i
on coil primary/secondary
circuit malfunction, cyl 3
P0353Ignit i
on coil primary/secondary
circuit malfunction, cyl 5
P0354Ignit i
on coil primary/secondary
circuit malfunction, cyl 7
P0355Ignit i
on coil primary/secondary
circuit malfunction, cyl 2
P0356Ignit i
on coil primary/secondary
circuit malfunction, cyl 4
P0357Ignit i
on coil primary/secondary
circuit malfunction, cyl 6
P0358Ignit i
on coil primary/secondary
circuit malfunction, cyl 8
P0400Exhaus t gas
recirculation (EGR)
flow malfunction
EGR valve c
onnector pins high
resistance
EGR pipe/exhaust manifol
d leak
EGR pipe blocke

d
EGR valve st

uck open/closed,
blocked
EGR valve fai
lure
For EGR
pinpoint t
ests,
REFER to Section 303
-08 En
gine
Emission Control.
P0405Exhaus
t gas
recirculation (EGR)
drive circuits open circuit
EGR valve power supply circuit
o p
en circuit
EGR valve t
o
ECM drive circuit pair
- EGR pins 1/3, 4/6 open circuit,
high resistance
EGR val v
e failure (stepper motor
open circuit)
For EGR pinpoint t
ests,
REFER to Section 303
-08 En
gine
Emissi
on Control.
P0406Exhaus t gas
recirculation (EGR)
drive circuits short circuit
EGR valve t o
ECM drive circuit pair
- EGR pins 1/3, 4/6 short circuit to
ground or high voltage
EGR val v
e failure (stepper motor
short circuit)
For EGR pinpoint t
ests,
REFER to Section 303
-08 En
gine
Emissi
on Control.
P0420Right-
hand catalytic converter
efficiency below threshold
HO2S di
sconnected.
HO2
S
to ECM wiring fault.
HO2
S
heater to ECM wiring fault.
HO2
S
heater failure.
HO2
S
failure.
Cat
a
lyst monitor sensor failure.
Catal
y
tic converter failure.
R
e
fer to pinpoint tests for components

listed. Visually inspect catalytic
converters.
P0442Evaporati v
e emissions system
(EVAP) leak detected
Fue l
filler cap missing
Fu

el filler cap seal faulty
EVAP system
leak (can
ister
damage, pipework damage)
EVAP v a
lve to ECM drive circuit
open circuit, short circuit, high
resistance
EVAP valve to engine pu rge pipe
damaged/blocked/leaking
EVAP ope r
ating vacuum hose
F
or evaporati
ve emissions pinpoint
tests,
REFER to Section 303
-1 3
Evaporative

Emissi
ons
.

Is
the resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to E4
.
E4
: CHECK THE H02S GROUND
CIRCUIT FOR OPEN CIRCUIT
Re
connect the ECM electrical connector, EM12.
1
Meas

ure the resistance between EM21, pin 04 (BRD) and GROUND.
2
Is th

e resistance greater than 5 ohms?
Yes
REPAIR the circuit (this is a braide d lead which would require different repair techniques to standard
wiring). For additional information, refer to the wiring diagrams. CL EAR the DTC. TEST the system for
normal operation.
No INSTALL a new H02S.
REFER to Heated Oxygen Sensor (HO2S) RH

in this section.
CLEAR the DTC. TEST the syst em for normal operation.
PI
NPOINT TEST F : DTC P0133, P0135; RIGHT-HAND H02S HEATER CIRCUIT MALFUNCTION
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
F1:

CHECK THE H02S HEATER POWER SUPPLY CIRCUIT
D

isconnect the H02S electrical connector, EM21.
1
Turn the ignition swi

tch to the ON
position.
2
Meas
ure the voltage between EM21, pin 02 (WP) and GROUND.
3
Is the vol

tage greater than 10 volts?
Yes GO to F2
.
No

REPAIR the circuit. This circuit in cludes the EMS control relay and fu se 14 of the EMS fuse board. For
additional information, refer to the wiring diagrams. CLEAR the DT C. TEST the system for normal
operation.
F2: CHECK THE H02
S HEATER CONTROL CI
RCUIT FROM ECM FOR HIGH RESISTANCE
Di
sconnect the battery negative terminal.
1
D

isconnect the ECM electrical connector, EM15.
2
Me

asure the resistance between EM15, pin 02 (PU) and EM21, pin 01 (PU).
3
Is th

e resistance greater than 5 ohms?
Yes REPAIR the high resistance circui t. For additional information, refer to the wiring diagrams. CLEAR
the DTC. TEST the system for normal operation.
No GO to F3
.
F3: CHECK THE H02
S HEATER CONTROL CIRCUI
T FROM ECM FOR SHORT TO HIGH VOLTAGE
R
econnect the battery negative terminal.
1
Turn the ignition swi

tch to the ON
position.
2
Meas
ure the voltage between EM21, pin 01 (PU) and GROUND.
3
Is th

e voltage greater than 3 volts?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to F4
.
F4: CHECK THE H02
S HEATER CONTROL CI
RCUIT FROM ECM FOR SHORT TO GROUND
Turn the ignition swi
tch to the OFF
position.
1
Meas
ure the resistance between EM21, pin 01 (PU) and GROUND.
2
Is

the resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No INSTALL a new H02S.
REFER to Heated Oxygen Sensor (HO2S) RH

in this section.

Yes

REPAIR the high resistance circui t. For additional information, refer to the wiring diagrams. CLEAR
the DTC. TEST the system for normal operation.
No GO to H2
.
H
2: CHECK THE H02S SENSE CIRCUIT FOR SHORT TO HIGH VOLTAGE
R

econnect the battery negative terminal.
1
Turn the ignition swi

tch to the ON
position.
2
M
easure the voltage between EM12, pin 14 (G) and GROUND.
3
Is th

e voltage greater than 3 volts?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to H3
.
H
3: CHECK THE H02S SENSE CIRCUIT FOR SHORT TO GROUND
Turn the ignition swi

tch to the OFF
position.
1
Meas
ure the resistance between EM12, pin 14 (G) and GROUND.
2
Is

the resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to H4
.
H4:
CHECK THE H02S GROUND CIRCUIT FOR OPEN CIRCUIT
Re

connect the ECM electrical connector, EM12.
1
Meas

ure the resistance between EM23, pin 04 (BRD) and GROUND.
2
Is th

e resistance greater than 5 ohms?
Yes REPAIR the circuit (this is a braide d lead which would require different repair techniques to standard
wiring). For additional information, refer to the wiring diagrams. CL EAR the DTC. TEST the system for
normal operation.
No INSTALL a new H02S.
REFER to Heated Oxygen Sensor (HO2S) RH

in this section.
CLEAR the DTC. TEST the syst em for normal operation.
P
INPOINT TEST I : DTC P0153, P0155; LEFT-HAND H02S HEATER CIRCUIT MALFUNCTION
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
I

1: CHECK H02S HEATER POWER SUPPLY CIRCUIT
D

isconnect the H02S electrical connector, EM23.
1
Turn the ignition swi

tch to the
ON position.
2
Meas
ure the voltage between EM23, pin 02 (WP) and GROUND.
3
Is the vol

tage greater than 10 volts?
Yes GO to I2
.
No

REPAIR the power supply circuit to the H02S heater. This circuit includes the EMS control relay and
fuse 14 of the EMS fuse board. For additional info rmation, refer to the wiring diagrams. CLEAR the
DTC. TEST the system for normal operation.
I
2: CHECK H02S HEATER CONTROL CIRC
UIT FROM ECM FOR HIGH RESISTANCE
Di
sconnect the battery negative terminal.
1
D

isconnect the ECM electrical connector, EM15.
2
Meas

ure the resistance between EM15,
pin 01 (PS) and EM23, pin 01 (PS).
3
Is th
e resistance greater than 5 ohms?
Yes REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the
DTC. TEST the system for normal operation.
No GO to I3
.
I
3: CHECK H02S HEATER CONTROL CIRCUIT
FROM ECM FOR SHORT TO HIGH VOLTAGE
R
econnect the battery negative terminal.