1998 JAGUAR X308 engine

REFE
R to Section 310
-00
Fu
el
Sy
ste
m
- General

Information
.
Check f o
r DTCs indicating a sensor
fault,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
P0174
Left-hand cyl i
nders combustion too
lean
Air in
take leak between MAF
sensor and throttle
F u
el filter system blockage
F
u
el injector blockage
F
u
el pressure regulator failure (low

fuel pressure)
Low f u
el pump output
H0
2S harness wiri
ng fault
E
x
haust leak (before catalyst)
ECM receivi
n
g incorrect signal from

one or more of the following sensors - ECT, MAF, IAT, TP
F o
r air intake sy
stem information,
REFER to Section 303
-12 Int
ake Air

Distribu tion and Filterin
g
.
Check the fuel fi lter,
REF
ER to Section 310
-01
Fu
el Tank
and Lines.
Chec k the
fuel injectors,
REFER to Fuel Injectors
- in t h
is
section.
For fuel pressure regulator check,GO
to Pinpoint Test D.
. Ch
eck the fuel
pressure,
REFER to Section 310
-00 Fu
el
Sy
ste
m
- General

Information
.
Check f o
r DTCs indicating which HO2

sensor is faulty,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
Check f o
r DTCs indicating a sensor
fault,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
P0175Left-hand cyli

nders combustion too
rich
Engine m
isfire
Bl
ocked air
filter
F
u
el system return blockage
Leak
i
ng fuel injector(s)
F
u
el pressure regulator failure
(high fuel pressure)
ECM receivi n
g incorrect signal from

one or more of the following sensors - ECT, MAF, IAT, TP
Check for 'en
gine misfire detected'
DTCs. Check the air filter element,
REFER to Section 303
-12 Int
ake Air

Distribu tion and Filterin
g
.
Chec k the
fuel lines,
REFER to Section 310
-01 Fu
el Tank
and Lines.
Chec k the
fuel injectors,
REFER to Fuel Injector
- Vehicles Wi
thout: Supercharger
/

Fue
l Injector
- Ve
hicles With
:
Supercharger
in this
section.
For fuel pressure regulator check,GO
to Pinpoint Test D.
. Check for DT
Cs
indicating a sensor fault,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
P0201F
u
el injector circuit malfunction, Cyl

1
Injector discon n
ected
Inject
or wir
ing open or short circuit

Injector fail
ure
F
o
r fuel injector circuit tests,GO to
Pinpoint Test A.
.
P0202Fu
el injector circuit malfunction, Cyl

3
P0203F u
el injector circuit malfunction, Cyl

5
P0204F u
el injector circuit malfunction, Cyl

7
P0205Fu
el injector circuit malfunction, Cyl

2
P0206Fu
el injector circuit malfunction, Cyl

4
P0207F u
el injector circuit malfunction, Cyl

6
P0208F u
el injector circuit malfunction, Cyl

8
P0300Ran d
om misfire detected
ECM t
o
ignition coil primary circuit
faults (cylinder misfire detected DTCs also logged)
Ignition coil ground circuit; open
ci
rcuit, high resistance
F
u
el injector circuit fault(s)
(injector DTCs also logged)
F o
r ignition circuit tests,
REFER to Section 303
-07 En
gine
Ignition.
F or engi
ne information,
REFER to Section 303
-00 En
gine
Sy
ste
m
- General

Information
.
F o
r fuel injector circuit tests,GO to

Ignition coil
failure(s)
HT sho

rt to ground (tracking)
check rubber boots for cracks/damage
Spark plug
failure/fouled/incorrect
gap
Cy
linder compression low
F

uel delivery pressure (low/high)
F

uel injectors restricted/leaking
Fuel contamination


P

AS pulley bolts loose (see Service

Action S462)
W
orn camshaft/broken valve
springs
P
inpoint Test
A.
.
Check fuel
pressure,
REFER to Section 310
-00
Fuel
Sy

stem
- General
Information
.
Chec
k fuel injectors,
REFER to Fuel Injectors
- in t
his
section.
Check service actions.
P0301Misfire
detected, Cyl 1
R
EFER to possible sources for P0300
R
EFER to actions for P0300.
P0302Misfire

detected, Cyl 3
P0303Misfire

detected, Cyl 5
P0304Misfire

detected, Cyl 7
P0305Misfire

detected, Cyl 2
P0306Misfire

detected, Cyl 4
P0307Misfire

detected, Cyl 6
P0308Misfire

detected, Cyl 8
P0460F

uel level sense signal performance
Fue
l level sensor
to instrument
cluster circuits in termittent short
or open circuit
F
uel level sensor failure
Instrument cluster
faul
t (incorrect
fuel level data)
F
or fuel level sensor tests,GO to
Pinpoint Test B.
.
P1224Throttl
e control position error
Thro
ttle adaptations not performed

after battery disconnect
TP se
nsor disconnected
TP se

nsor to ECM sense circuits;
open circuit, hi gh resistance
Throttl
e motor relay failure
Th

rottle motor relay to ECM circuit

fault
Throttl
e motor relay power supply
open circuit
ECM ground circuit faul
t (relay coil
drive)
Throttl
e motor to ECM drive
circuits; open circuit, short circuit, high resistance
Throttl
e motor failure
Throttl

e body failure
Carry
out the throttle adaptation
procedure,
REFER to Section 303
-14
Electronic
Engine

Controls
.
ECM adaptations. For
throttle motor
relay tests, throttle position sensor tests, ECM ground tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
P1229Throttl

e motor control circuit
malfunction
Throttl
e motor disconnected
Throttl

e motor to ECM drive
circuits; short circuit or open circuit
Throttl
e motor failure
Fo
r throttle moto
r relay tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
P1250Engine

load malfunction
Air
intake leak
Engine

breather leak
TP se

nsor circuit fault (DTC P0121)

Throttl
e valve spring failure
F
or air intake system,
REFER to Section 303
-12
Intake Air

Distribu
tion and Filtering
.
Chec
k engine breather system for
leaks. For TP sensor tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
P1313Right-hand cylinders misfire rate
cat
alyst damage (this DTC will flag
only when accompanied by an
individual cylinder misfire DTC: P0300-P0308)
R
efer to possible causes for P0300-P0308
R
efer to actions for P0300-P0308.
P1314L

eft-hand cylinders misfire rate
catalyst damage (this DTC will flag only when accompanied by an
individual cylinder misfire DTC: P0300-P0308)
R
efer to possible causes for P0300-P0308
R
efer to actions for P0300-P0308.

Pinpoint Tests
P1316Mi
sfire excess emission (this DTC
will flag only when accompanied by an individual cylinder misfire DTC: P0300-P0308)
Re
fer to possible causes for P0300-P0308
R
e
fer to actions for P0300-P0308.
P1611Thr
o
ttle angle malfunction
TP sensor
ci
rcuit fault
APP sensor circuit faul
t Throttle
assembly failure
ECM failu
r
e
F
or TP and APP
sens
or circuit tests,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
F o
r throttle assembly information,
refer to throttle body in this section.
Contact dealer technical support for advice on possible ECM failure.
P1612Throttl e
offset malfunction
TP sensor
ci
rcuit fault
APP sensor circuit faul
t Throttle
assembly failure
ECM failu
r
e
F
or TP and APP
sens
or circuit tests,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
F o
r throttle assembly information,
refer to throttle body in this section.
Contact dealer technical support for advice on possible ECM failure.
P1646Fu
el pump 2 relay malfunction (this
DTC applies only to the
supercharger secondary fuel pump)
Fu
el pump 2 relay failure
Fu

el pump 2 relay to ECM circuit
fault
Fu
el pump 2 relay coil power
supply open circuit
ECM ground circuit faul t (relay coil

drive)
For fuel pump 2 r
elay circuit tests,
GO to Pinpoint Test C.
.
PI
NPOINT TEST A : DTC P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208; FUEL
INJECTOR CIRCUIT MALFUNCTION
• NOTE
: The DTC set will indicate which cylinder injector or circ
uit is faulty. Only in the event of multiple cylinder misfires
will it be necessary to chec k more than one injector or circuit, in which case, multiple DTCs will be set.
TES
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
A1
: CH
ECK THE INJECTOR COIL RESISTANCE
Turn the ignition swi
t
ch to the OFF
position.
1
Disconne
ct the relevant injector electrical connector
, (IJ03 to IJ10, vehicles with AJ26 engine, PI07 to
PI14, vehicles with AJ27 engine).
2
Meas ure t
he resistance between the injector pins.
3
Is
t
he resistance between 12 and 16 ohms?
Yes GO to A2
.
No
INST
ALL a new injector.
REFER to Fuel Injector
- Ve hicles With
out: Supercharger

in this
section.
CLEAR the DTC. TEST the system for normal operation.
A2: CHECK
THE INJECTOR COIL INSULATION
Meas
ure t
he resistance between the inje
ctor pin 01 and the injector body.
1
Measure t
he resistance between the inje
ctor pin 02 and the injector body.
2
Are both re
sistances greater than 10 Mohms?
Yes GO to A3
.
No
INST
ALL a new injector. CLEAR the DTC. TE
ST the system for normal operation.
A3: CHECK THE INJECTOR
SUPPLY VOLTAGE
Turn the ignition swi
t
ch to the ON
position.
1
Disconne
ct the relevant injector electrical connector
, (IJ03 to IJ10, vehicles with AJ26 engine, PI07 to
PI14, vehicles with AJ27 engine).
2
Meas ure t
he voltage between the relevant injector harness electrical connector (IJ03 to IJ10, vehicles

with AJ26 engine, PI07 to PI 14, vehicles with AJ27 engine), pin 02 (BR) and GROUND.
3
Is the volt
age greater than 12 volts?
Yes GO to A4
.
No
R
EPAIR the circuit between the relevant injector harn
ess electrical connector, pin 02 and battery. This

ci
rcuit includes the EMS fuse box,
fuse 05, and the fuel injection relay. For additional information,
refer to the wiring diagrams. CLEAR DTC. TEST the system for normal operation.
A4: CHECK
THE INJECTOR GROUND
CIRCUIT FOR HIGH RESISTANCE
Turn the ignition swi
tch to the OFF
position.
1
Di
sconnect the battery negative terminal.
2
D

isconnect the ECM electrical connector, (EM15, vehi
cles with AJ26 engine, EM84, vehicles with AJ27
engine).
3
Meas
ure the resistance between the relevant injector harness electrical connector (IJ03 to IJ10,
vehicles with AJ26 engine, PI07 to PI14, vehicles with AJ27 engine), pin 01 and the ECM electrical
connector, pins as follows -
Vehicles with AJ26 engine:
Cy
l 1 IJ03, pin 01 (BU) and EM15, pin 07
Cy

l 2 IJ07, pin 01 (BU) and EM15, pin 18
Cy

l 3 IJ04, pin 01 (BN) and EM15, pin 17
Cy

l 4 IJ08, pin 01 (BN) and EM15, pin 05
Cy

l 5 IJ05, pin 01 (BG) and EM15, pin 16
Cy

l 6 IJ09, pin 01 (BG) and EM15, pin 04
Cy

l 7 IJ06, pin 01 (BW) and EM15, pin 06
Cy

l 8 IJ10, pin 01 (BW) and EM15, pin 15
Vehicles with AJ27 engine:
Cy
l 1 PI07, pin 01 (B
G) and EM84, pin 02
Cy
l 2 PI11, pin 01 (BW) and EM84, pin 06
Cy

l 3 PI08, pin 01 (BO) and EM84, pin 21
Cy

l 4 PI12, pin 01 (BW) and EM84, pin 04
Cy

l 5 PI09, pin 01 (B
G) and EM84, pin 14
Cy
l 6 PI13, pin 01 (BO) and EM84, pin 03
Cy

l 7 PI10, pin 01 (BW) and EM84, pin 05
Cy

l 8 PI14, pin 01 (BR) and EM84, pin 13
4
Is th

e resistance greater than 5 ohms?
Yes REPAIR the circuit between the relevant injector harness electrical connector pin 01 and the engine
control module electrical connecto r. For additional information, refer to the wiring diagrams. CLEAR
the DTC. TEST the system for normal operation.
No GO to A5
.
A5: CHECK
THE INJECTOR GROUND CI
RCUIT FOR SHORT CIRCUIT TO BATTERY
R
econnect the battery negative terminal.
1
Meas

ure the voltage between the relevant injector harness electrical connector (IJ03 to IJ10, vehicles

with AJ26 engine, PI07 to PI14, vehicles with AJ27 engine), pin 01 and GROUND.
2
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 A6
.
A6: CHECK
THE INJECTOR GROUND CI
RCUIT FOR SHORT CIRCUIT TO GROUND
Meas
ure the resistance between the relevant injector harness electrical connector (IJ03 to IJ10,
vehicles with AJ26 engine, PI07 to PI14, vehicles with AJ27 engine), pin 01 and GROUND.
1
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 Contact dealer technical support for advice on possible ECM failure.
P
INPOINT TEST B : DTC P0460; FUEL
LEVEL SENSE SIGNAL PERFORMANCE
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
B1: CHECK

THE FUEL LEVEL SENSOR REFERENCE GROUND
Di

sconnect the fuel level sensor electrical connector, BT15.
1

C2: CHECK THE FUEL
PUMP 2 RELAY TO ECM CIRCUIT
Di

sconnect the battery negative terminal.
1

D
isconnect the ECM electrical connector, EM13.
2

Meas
ure the resistance between the rela
y base, pin 02 and EM13, pin 09 (KB).
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 INSTALL a new fuel pump 2 relay. CLEAR the DT C. TEST the system for normal operation.
P
INPOINT TEST D : CHECK THE FUEL PRESSURE REGULATOR FUNCTION
CAUTI
ON: Do not run the engine for more than
30 seconds with the vacuum hose disconnected.
T
EST CONDITIONS
D
ETAILS/RESULTS/ACTIONS
D

1: CHECK FOR FUEL PRESSURE CHANGE
WHEN THE REGULATOR IS DISCONNECTED
Connect a
fuel pressure gauge set,
REFER to Section 310
-00
Fuel System
-

General Informati
on
. 1

St
art the engine.
2

N
ote the fuel pressure readin
g with the fuel pressure regu lator vacuum hose connected.
3

Di
sconnect the fuel pressu
re regulator vacuum hose.
4

N
ote the new reading.
5

Doe
s the fuel pressure increase when the hose is disconnected?
Yes Check for DTCs. Carry out the pinpoint tests indicated.
No INSTALL a new fuel presssure regulator. TEST the system for normal operation.
P
INPOINT TEST E : DTC P1230;
FUEL PUMP RELAY MALFUNCTION
•
NOTE: This DTC applies only to the N/A system si
ngle fuel pump, and the S/C system fuel pump 1
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
E1

: CHECK THE FUEL PUMP
RELAY BATTERY SUPPLY
R
emove the fuel pump relay.
1

Meas
ure the voltage between the
relay base, pin 03 and GROUND.
2

Is th
e voltage less than 10 volts?
Yes REPAIR the circuit between the rela y base, pin 03 and the battery power bus. This circuit includes the
trunk fuse box and the high power protection module . For additional information, refer to the wiring
diagrams. CLEAR the DTC. TEST th e system for normal operation.
No GO to E2
.
E2
: CHECK THE FUEL PUMP RELAY IGNITION SWITCHED SUPPLY
Turn the ignition swi

tch to the
ON position.
1

Meas
ure the voltage between the
relay base, pin 01 and GROUND.
2

Is th
e voltage less than 10 volts?
Yes REPAIR the circuit between the rela y base, pin 01 and battery. This circuit includes the trunk fuse box,

fuse 16 of the left-hand fuse box, the ignition po
sitive relay and the high power protection module.
For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal
operation.
No GO to E3
.
E3
: CHECK THE FUEL PUMP RELAY TO
ECM CIRCUIT FOR HIGH RESISTANCE
Di
sconnect the battery negative terminal.
1

D
isconnect the ECM electrical connector, EM83.
2

Meas
ure the resistance between EM83, pi
n 04 (WR) and the relay base, pin 02.
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

INSTALL a new fuel pump relay. CLEAR the DTC. TEST the system for normal operation. If the DTC is
repeated, contact dealer technical support for advice on possible ECM failure.

Fuel Ch
arging and Controls
- Fuel Injector4.0L NA V8 - AJ27/3.2L NA V8 -
AJ26
Re
moval and Installation
Remov

al
S
pecial Tool(s)

R

emover - Fuel Injector
303-539 (JD 231)
1. Disconnect battery ground cable (IMPORTANT, see SRO
86.15.19 for further information).
2. WARNING: BEFORE PROCEEDING, IT IS ESSENTIAL THAT
THE WARNING NOTES GIVEN IN SECTION 100-00 (UNDER THE
HEADING 'SAFETY PRECAUTIONS') ARE READ AND
UNDERSTOOD.
Depressurize the fuel sy stem; refer to 19.50.02.

3. R
emove engine covers.

4. Di
sconnect bank 1 or 2 inject
or connectors and reposition
harness to allow access to injectors.
5. Remove bolts which secure fuel injector clamp plate to inlet
manifold.

Accessory Drive - Accessory Drive

Description an
d Operation

Parts List
Cran
kshaft Pulley
The combined crankshaft
pulley and torsio
nal vibration damper drives a single, seve n ribbed vee belt. The belt drives all of
the engine-mounted accessories; the generator, the power assi sted steering pump, the air-conditioning compressor and the
coolant water pump.
I
dler Pulley
An i
dler pulley, on the right-hand
accessory mounting, increases the wrap-angle around the generator pulley.
Coolant Pump Drive
The coolan
t pump pulley is the
uppermost of the accessory drive pulleys. Th e coolant pump is fitted between the two
cylinder banks on the front face of the engine.
Air Conditioning Compressor Drive

Thi

s is positioned at the lowest poin
t of the front-end accessory-d rive on the left hand side accessory mounting.
It
em
Par
t Number
De
scription
1—Coo

lant Pump Drive
2—Ai

r-Conditioning Compressor Drive
3—Power Steer

ing Pump Drive
4—Au

tomatic Belt Tensioner
5—Crankshaft Pul

ley
6—Idle

r Pulley
7—Generator Dri

ve

The
automatic belt tensioner consists of an idler pulley which is
free to rotate on a bearing, located at the end of a spring-
loaded pivot arm.
The pivot arm can be turned counter-clockwise (viewed from th e front of the engine) for belt removal and installation.
A belt-wear indicator is incorporated on th e rear horizontal face of the pivot arm.
It
em
De
scription
1Bel

t Wear Indicator
2Re

new Belt Indicator
3N

ew Belt Maximum Length
4N

ew Belt Minimum Length
Au
tomatic Belt Tensioner