1998 JAGUAR X308 air intake

Fuel D
istribution
Fuel is supplied to th
e engine
via eight fuel injectors (one pe r cylinder). The injectors are located in two fuel rails which r un
the length of each cylinder bank and ar e integral with the air intake manifold.
Fuel pumped from the tank enters a feed pipe at the rear of bank 2. Fuel flow is along bank 2 fuel rail, across the top front
of the engine (cross-over pipe) and through bank 1 fuel rail, the unused fuel re turning to the tank via a pressure regulator.
The fuel injectors are each controlled electrically from the engine control module (ECM).
A test valve is fitted to the cross-over pipe connecting the fu el rails at the front of the intake manifold. This valve allows the
fuel system to be depr essurized during servicin g and troubleshooting.
Fuel Injector

Eight, side-fed, dual straight-jet fuel injectors are fi tted in the fuel rails.
The injector consists of a solenoid, core, needle valve and ho using. When a control signal from the ECM is applied to the
solenoid coil, the needle valve lifts up and fuel is injected under pressure into the intake port. The fuel sprays from the
injectors are directed onto the back of the intake valves.
The injection quantity is determined by the length of time that the ECM signal is applied to the solenoid coil.
The injectors installed in the fuel rails of supercharged engines are of a higher flow rating than those installed in normally
aspirated engines and are secured in position by spring clips. Seals are instal led between the injector mounts of the fuel
rails and the related re cesses in the charge air cooler adaptors.
Pressure Regulator

Fuel Char
ging and Controls - Fuel Charging and Controls
D
iagn
osis and Testing
I
n
spection and Verification
1.
1. Veri fy the customer concern.
2. 2. Confi
rm which, if any, warning li
ghts and/or messages were displayed on the instrument cluster.
• NOTE: If any warning lights and/or me ssages were displayed when the fault occurred, refer to the Driver Information
table for DTCs associated with the display, then to the DTC index table for possible sources and actions. Some warnings will
appear to clear when the ignition is cycl ed. This is often because the warning has flagged as a resu lt of one of the vehicle's
on-board diagnostic routines having run to detect the fault. If the same routine is not run when the ignition is switched ON,
the warning will not reflag until the routine does run. See the DTC summaries for drive cycle routines.
3. 3. Visually inspect for obvious signs of mechanical or electrical damage.
Vi
sual Inspection Chart
4.
4. Veri fy the foll
owing syst
ems are working correctly:
Air intake
system
Cooling system


Charging system
5. 5. If
an obvious cause for an observed or
reported concern is found, correct th e cause (if possible) before proceeding
to the next step.
6. 6. Where the Jaguar approved diagnostic sy stem is available, complete the S93 report before clearing any or all fault
codes from the vehicle.
• NOTE: If a DTC cannot be cleared, then there is a permanent fault present that flag s again as soon as it is cleared (the
exception to this is P1260, which will only clear following an ignition OFF/ON cycle after rectification).
7. 7. If the cause is not visually evident and the Jaguar approv ed diagnostic system is not available, use a fault code
reader to retrieve the fault codes be fore proceeding to the Diagnostic Trou ble Code (DTC) Index Chart, or the
Symptom Chart if no DTCs are set.
• NOTE: If the DTC flagged was not present for two or more co nsecutive cycles, it is classed as temporary, and will be
deleted following three cycl es during which no fault was present. This could result in a reported wa rning light/message with
no stored DTCs. If a fault is present for three consecutive cycles, the DTC becomes permanent, and will remain in the
module's memory for 40 drive cycl es (a cycle is an ignition OFF/ON, which will occur during the owner's normal use of the
vehicle. No action on the part of the technician is necessary to perform this cycle. A drive cycle is a series of conditions
needed to make the on-board diagnostic ro utine run, and may need a specific action on the part of the technician. See the
DTC summaries for drive cycle routines).
8. 8. Using the Jaguar approved diagnostic system where available, and a scan tool where not, check the freeze frame
data for information on the conditions applicable when the fault was flagged. The format of this will vary,
depending on the tool used, but can pr ovide information useful to the technician in diagnosing the fault.
MechanicalElectrical
Engine
oil level
Coo
ling system coolant
lev
el
Fuel contamination
Throttle body Poly-ve
e belt
Fu
ses
W
i
ring harness
E
l
ectrical connector(s)
Sens
o
r(s)
Engine
control module (E
CM)
Tran
s
mission control module
Check spark plu
g type. Only r
e
sisted plugs should be fitted. Refer to specifications
section for gap
Relay date codes. I
f the date on the rela
y is between R6 k1 and R6 k8, replace the
relay

(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.

Driver Informa
tion Chart
•
NOTE: Use this table to identify DTCs associated with the me
ssage center display, then refer to the DTC index for possible
sources and actions.
• NOTE: For definitions of Default Modes, see the foot of this table.
Engine deton
ates/knocks
Fue
l pump
HO2 sensors Air leakage Blocked part-load breather
(
service action S474)
Mass ai

r flow (MAF) sensor
Chec
k fuel pressure.
REFER to Section 310
-00
Fuel System
- Gen
eral
Informati

on
.
F
or HO2 sensor circuit
tests, check for DTC
indicating which sensor and follow indicated
pinpoint test. For intake system information,
REFER to Section 303
-1
2 Intake Air Distribution
and F

iltering
.
Check service
action S474. For MAF sensor circuit
tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
No

throttle response
Throttl
e sensors
Throttl

e motor
F
or throttle position se
nsor and throttle motor
relay tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
Poor throttle responseThrottl

e sensors
Throttl

e motor
Air leakage Mass ai

r flow (MAF) sensor
F
or throttle position se
nsor and throttle motor
relay tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
Fo
r intake system,
REFER to Section 303
-1
2 Intake Air Distribution
and F

iltering
.
For MAF
sensor tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
Warning
lightMess
age
De
fault Mode
DT
C
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P1224
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P1229
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P01
22, P0123,
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P02
22, P0223
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P0121
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P11
22, P1123
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P12
22, P1223
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P11
21, P1632
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P12
51, P0560, P1658
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P1631
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P1611
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P1633
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P1609
Re

d
Engine
Failsafe
Mode
Lim
p-Home
P05
06, P0507
Re

d
Engine
Failsafe
Lim
p-Home
P1656

Default mode Definitions

MECH
ANICAL LIMP-HOME MODE:

No el
ectronic throttle operation (mechanical
operation for last quarter of pedal travel)
M
aximum 25° throttle opening,
depending on adjustment of th rottle mechanical linkage
Engine
speed restricted to 3000
rpm maximum, by fuel cut-off
Hi
gh idle speed (1200 rpm approx.)
Misfire

at idle, due to cylinder cut as a means of control
ling idle speed (the misfire will switch cylinders, as the
strategy varies th e cylinder cut)
Cruise (speed) contr
ol inhibited
REVERSE THROTTLE PROGRESSION ENABLED:
El
ectronic throttle operation, limited to maximum 25°
Cruise (speed) contr

ol inhibited
• NOTE: The throttle oper ation uses the same map as for reverse gear.
ENGINE SPEED LIMIT:
Engine
runs normally, up to 3000 rpm
Engine

speed restricted to 3000
rpm maximum, by fuel cut-off
Cruise (speed) contr
ol inhibited
LIMP-HOME UNAVAILABLE:
Cruise (speed) contr
ol inhibited
R

everse throttle pr
ogression engaged at second occurrence of DTC flagging
Diagnostic Trouble Code (D
TC) index
DT
C
Cond
ition
P
ossible Causes
Acti
on
P0171Right-hand cylinders combustion too

leanAir
intake leak between MAF
sensor and throttle
F
uel filter system blockage
F

uel injector blockage
F

uel pressure regulator failure (low

fuel pressure)
Low f
uel pump output
H0

2S harness wiring fault
E

xhaust leak (before catalyst)
ECM receivi

ng incorrect signal from

one or more of the following
sensors - ECT, MAF, IAT, TP.
Fo
r intake system,
REFER to Section 303
-12
Intake Air

Distribu
tion and Filtering
.
F
or fuel filter,
REFER to Section 310
-01
Fuel Tank
and Lines.
Chec
k the fuel injectors. Check the
fuel pressure regu lator. Check fuel
pressure. For HO2S circuit tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
F
or exhaust information,
REFER to Section 309
-00
Exhaust
Sy

stem
.
For se
nsor circuit tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
P0172Right-hand cylinders combustion too

ri
ch
Engine
misfire
Bl

ocked air filter
F

uel system return blockage
Leak

ing fuel injector(s)
F

uel pressure regulator failure
(high fuel pressure)
ECM receivi
ng incorrect signal from

one or more of the following sensors - ECT, MAF, IAT, TP
Chec
k for 'engine misfire detected'
DTCs. Check the air filter element,
REFER to Section 303
-12
Intake Air

Distribu
tion and Filtering
.
Chec
k the fuel lines,
REFER to Section 310
-01
Fuel Tank
and Lines.
Chec
k the fuel injectors,
REFER to Fuel Injectors
- in t
his
section.
For fuel pressure regulator check,GO
to Pinpoint Test D.
.
Check the fuel
pressure,

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.

1.
Install
fuel injector(s).
1. Install new O-rings, lubricated with petroleum jelly, to
fuel injector.
2. Install fuel in jector into fuel rail. Press firmly until it is
felt to click into place.
3. Hold injector firmly down and fit injector securing clip
in the correct orientation.

2. Conne
ct fuel injector harness.
1. Reposition harness.
2. Tighten nuts which secure harness to camshaft cover.
3. Re-connect injectors.
3. Install charge air c ooler; refer to 18.50.18 and / or 18.50.19.
4. Install supercharger asse mbly; refer to 18.50.15.
5. Install supercharger driv e belt; refer to 18.50.08.
6. Install coolant outlet pi pe; refer to 26.31.08.
7. Install throttle induction elbow; refer to 19.70.28.
8. Install exhaust gas re-circulation valve (EGR) if applicable;
refer to 17.45.01.
9. Install throttle body ; refer to 19.70.04.
10. Install supercharger outlet duct; refer to 18.50.16.
11. Install air cleaner cover / intake assembly; re fer to 19.10.30.
12. Refill cooling system; refer to (SC) 26.10.01 .
13. Reconnect battery ground cable (IMPORTANT, see SRO
86.15.15 for further information).