1998 JAGUAR X308 air filter

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.

F
or evaporative emissions components,
REFER to: Evaporative Emissions
(30
3-13
Evaporative Emissions, Diagnosis and Testing).
For ECT sensor tests,
REFER to: Electronic Engine Controls
(30
3-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
Engine stalls
soon after start
F
uel pump relay
ECM relay


Harness damage Fue

l pump
Engine coolan

t temperature
(ECT) sensor
Fue
l lines
F

uel pressure regulator
Air leakage


Check f
or DTCS. For fuel pump and ECM relay
tests,
REFER to: Fuel Charging and Controls
(30
3-04

Fuel Charging and Controls, Diagnosis and Testing).
Check fuel pressure.
REFER to: Fuel System Pressure Check
(31
0-
00 Fuel System - Genera l Information, General
Procedures).
For ECT sensor tests,
REFER to: Electronic Engine Controls
(30
3-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For fuel line information,
REFER to: Fuel Tank and Lines
(31
0-01 Fuel
Tank and Lines, Description and Operation).
For fuel pressure regulator,
REFER to: Fuel Charging and Controls
(30
3-04

Fuel Charging and Controls, Diagnosis and Testing).
For intake system information,
REFER to: Intake Air Distribution and Filtering

(30
3-12 Intake Air Distribution and Filtering,
Description and Operation).
Engine hesi
tates/poor acceleration
Fue
l pump
Air leakage


F

uel pressure regulator
Fue

l lines
Harness damage Throttl

e sensors
Throttl

e motor
Spark

plugs fouled, gapped
incorrectly
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
Exhaus
t gas recirculation (EGR)

(SC only)
Chec
k fuel pressure,
REFER to: Fuel System Pressure Check
(31
0-
00 Fuel System - Genera l Information, General
Procedures).
For intake system information,
REFER to: Intake Air Distribution and Filtering

(30
3-12 Intake Air Distribution and Filtering,
Description and Operation). For fuel pressure regulator,
REFER to: Fuel Charging and Controls
(30
3-04

Fuel Charging and Controls, Diagnosis and Testing).
For fuel lines information,
REFER to: Fuel Tank and Lines
(31
0-01 Fuel
Tank and Lines, Description and Operation).
For throttle position se nsor and throttle motor
relay tests,
REFER to: Electronic Engine Controls
(30
3-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For spark plug tests, GO to Pinpoint Test B.
.
For ign
ition system tests, GO to Pinpoint Test
A.
. F
or EGR information,
REFER to: Engine Emission Control
(30
3-08
Engine Emission Cont rol, Description and
Operation).
Engine ba
ckfires
Fue
l pump
Fue

l lines
Air leakage


Mass ai

r flow (MAF) sensor
Spark plugs


Check f

or water ingress into
spark plug wells
HT sho
rt to ground (tracking)
check rubber boots for cracks/damage
Chec
k fuel pressure,
REFER to: Fuel System Pressure Check
(31
0-
00 Fuel System - Genera l Information, General
Procedures).
For fuel pump and lines,
REFER to: Fuel Tank and Lines
(31
0-01 Fuel
Tank and Lines, Description and Operation).
For intake system,
REFER to: Intake Air Distribution and Filtering

(30
3-12 Intake Air Distribution and Filtering,
Description and Operation). For MAF sensor tests,

Driver Information
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.
REF E
R 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.
.
Engine s
urges
Air leakage
Fue
l
pump
Fue
l
lines
Mass ai
r fl
ow (MAF) sensor
Harness damage Throttl
e
sensors
Throttl
e
motor
Spark plugs
Check fo
r water ingress into
spark plug wells
HT short to ground (tracking) check rubber
boots for
cracks/damage
Fo r
intake system,
REFER to: Intake Air Distribution and Filtering

(30 3
-12 Intake Air Distribution and Filtering,
Description and Operation). Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For fuel pump and lines,
REFER to: Fuel Tank and Lines
(310
-01 Fuel
Tank and Lines, Description and Operation).
For MAF sensor, throttle position sensor and
throttle motor relay 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.
.
Engine detonates/k
nocks
Fue
l
lines
F
u
el pressure regulator
Air leakage
Mass air fl
ow (MAF) sensor
O
xygen senso
rs
Fue
l
pump
F
o
r fuel lines,
REFER to: Fuel Tank and Lines
(310
-01 Fuel
Tank and Lines, Description and Operation).
For fuel pressure regulator,
REFER to: Fuel Charging and Controls
(303
-04

Fuel Charging and Controls, Diagnosis and Testing).
For intake system,
REFER to: Intake Air Distribution and Filtering

(30 3
-12 Intake Air Distribution and Filtering,
Description and Operation).
For MAF sensor and oxyg en sensor tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
No t
hrottle response
Throttl
e
sensors
Throttl
e
motor
Fo
r th
rottle position sensor tests, throttle
motor relay tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
Poor throttle responseThrottl e
sensors
Throttl
e
motor
Air leakage Mass air fl

ow (MAF) sensor
F
or throttl
e position se
nsor and throttle motor
relay tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For intake system,
REFER to: Intake Air Distribution and Filtering

(30 3
-12 Intake Air Distribution and Filtering,
Description and Operation). For MAF sensor tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).

Diagnostic Trouble Code (D
TC) Index
Pinpoint Tests
Fue
l lines
Harness damage


Throttl

e sensors
Throttl

e motor
Spark plugs

fouled
Ignition coil

failure(s)
HT sho

rt to ground (tracking) check
rubber boots for cracks/damage
Exhaus
t gas recirculation (EGR)
F
or air intake syst
em information,
REFER to Section 303
-12
Intake Air

Distribu
tion and Filtering
.
F
or fuel pressure
regulator tests,
REF
ER to Section 303
-04
Fuel
Charging and Con

trols
.
F
or fuel line information,
REFER to Section 310
-01
Fuel Tank

and Lines.
F
or throttle sensor
circuit tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
Fo
r throttle motor
circuit tests,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
For ign
ition system tests,
REFER to Section 303
-07
Engine
Ignition.
Inspe
ct EGR components, for circuit
tests, GO to Pinpoint Test A.
.
DT
C
De
scription
Possib
le Source
Acti
on
P0400Exhaus

t gas
recirculation (EGR) flow malfunction
EGR
valve connector pins high
resistance
EGR pipe/exhaust manifold leak EGR pipe block
ed
EGR val

ve stuck open/closed,
blocked
EGR
valve failure
Check the EGR pi
pe, valve and manifold for
leaks/blockages. Check the EGR valve function.
For EGR valve circuit tests,GO to Pinpoint Test A.
.
P0405Exhaus
t gas
recirculation (EGR) drive
circuits open circuit
EGR valve power supply circuit o
pen circuit
EGR valve t

o ECM drive circuit
pair - EGR pins 1/3, 4/6 open circuit, high resistance
EGR val
ve failure (stepper motor
open circuit)
F
or EGR valve circuit tests,GO to Pinpoint Test
A.
.
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
ve failure (stepper motor
short circuit)
F
or EGR valve circuit tests,GO to Pinpoint Test
A.
.
P
INPOINT TEST A : DTC P0400, P0405; EGR VALV
E FLOW MALFUNCTION/DRIVE CIRCUITS OPEN
CIRCUIT
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
A1: CHECK

THE EMS POWER SU
PPLIES TO THE EGR VALVE
D
isconnect the EGR valve electrical connector, PI34.
1
Turn the ignition swi

tch to the ON
position.
2
Make sure the EMS re lay i
s energized.
Vehicles with AJ26 engine:
Me
asure the voltage between PI34, pins 02 and 05 (WP) and GROUND
Vehicles with AJ27 engine:
Me
asure the voltage between PI34, pins 02 and 05 (WU) and GROUND
3
Is th

e voltage at either pin less than 10 volts?
Yes

Intake Air Distribution and Filtering -
Torque Specificat
ions


Comp

onent
Nm
Thr
o
ttle intake elbow to intake manifold
18
-
24
Thro
tt
le body to throttle intake elbow
18
-
24
Left-hand support
bracket to
th
rottle intake elbow
16
-
20
Right-hand support
bracket to
throttle intake elbow
16
-
20
B
l
anking plate to throttle intake elbow
18
-
24
Inta
k
e manifold to engine
20
-
22
Supe
rcharger
drive belt idler pulley bolt
34
-
46
Supercharger
drive belt te
nsioner to alternator mounting bracket bolt
39
-
51
Supercharger
to eng
ine bolts
18
-
24
Charge air cooler in
let assembly to charge ai
r cooler bolts
18
-
24
Supercharger
outlet duct to supercharger bolts9-1
1
Charge air cooler in
let assembly to superchar
ger ou
tlet duct bolts
18-
24
Charge air cool
er to charge
air cooler adaptor
11
-
13
B
y
-pass valve to throttle intake elbow
8-
1
2

Intake Air Distribution and Filtering - Intake Air Distribution and Filtering
Description an
d Operation
I

ntake Air Distribution and Filtering - Normally Aspirated Vehicles
Air Intake Asse
mbly

The air cleaner assembly consists of a two piece box containing the air filter, an airflow/temperature unit and the air intake
duct which connects to the top of the throttle assembly. The en gine full load breather feeds into the intake duct from the
bank 1 camshaft cover. A tuned stub on the ai r intake duct reduces the intake noise level.
Mass Air Flow and Temperature Sensors

The intake air is monitored by the Mass Air Flow (MAF) sensor assembly which is fitted at the outlet of the air filter
assembly. Two sensors are incorporated in the MAF sensor assembly, measuring air flow and temperature (temperature
sensor arrowed); both sensors provide anal ogue signal inputs to the engine control module (ECM) and are further described
in Section 303-14.

P
arts List
CAUTION: Do not attempt to renew or adjust the throttle cable without consulting the relevant procedure. Two
procedures apply: reconnection of an original cable (19.70.04) or the fitting of a new cable (19.20.06).
The filtered air from the intake duct is drawn downwards through the throttle body to the intake elbow on which the throttle
body is mounted. The airflow through the throttle body is vari ed by the electrically operated throttle valve according to
driver demand and engine mana gement system requirements.
The throttle body assembly has the following features:
Con
vential cable operated input shaft connected to the accelerator pedal.
M

echanical guard to limit throttle angl
e should driver demand exceed ECM co ntrolled parameters and a mechanical
back-up in the event of a throttle motor failure.
Vacuum actuator for operation of the mech anical guard in cru
ise control mode.
Thr

ottle valve (blade) to regula
te air flow into the engine.
Thermostatic air valve to allow and con
t
rol air by-pass around the throttle.
D
C electric motor to operate the thro
ttle in response to ECM control.
Three
sensors (accelerator pedal, mechan
ical guard and the throttle valve) to relay positional information about the
input shaft to the ECM.
R
eturn and control springs fitted to th
e input shaft, mechanical guard, thro ttle valve and dc motor drive gear.
Throttle Cont
rol Modes
There are seven throttle control

modes:
1. 1. Normal
It
em
Par
t Number
De
scription
1—Acce

lerator pedal and mechanic
al guard position sensors
2—Throttl
e (blade)
position sensor
Throttle Body

the
intake elbow provide connections for vacuum actuators and are also used to redirect emissions into the engine.
On the right-hand side of the elbow a la rge diameter pipe connects to the brake servo. The smaller pipe provides a vacuum
feed to the fuel rail pressure regulator and throttle cruise control system. On the le ft-hand side of the elbow the front pipe
supplies vacuum control for the evaporative emissions system valves.
Emissions from the engine part load breather (bank 2) and pu rged fuel vapor from the EVAP valve are drawn via a common
T piece into the left-hand side of the intake elbow. Re-cir culated exhaust gas enters the intake elbow via the EGR valve
which is mounted directly on the rear of the elbow : where the EGR system is not used, a blanking plate is fitted.
The fuel system, throttle and emission control system s are described more fully in the relevant sections.
Intake Manifold

Filtered air from the vehicle's intake ducting is metered by th e electronic throttle and distributed to the two cylinder banks
via an integral intake manifold.
The intake manifold is manufactured in plastic with integral plastic fuel rails and metal-thread inserts; the very smooth
internal surfaces give excellent air flow.
Individual ducts lead off a central chamber to the inlet valves of each cylinder.
Silicon-rubber gaskets, loca ted in channels in the intake manifold, seal th e joints between the ducts and the cylinder heads.
Engine Ventilation

The e
ngine is ventilated through two brea
thers; a part-load breather and a full-load breather, one on each camshaft cover.
The outlet hose for the part-load breather is connected between the bank 2 camshaft cover and the intake elbow. The full-
load outlet hose is connected from the bank 1 camshaft cover to the intake duct between the MAF sensor assembly and the
throttle body.
Constructed in plastic, the hoses incorporate O-ring seal s and quick-release connectors; refer to Section 303-01.
I
ntake Air Distribution and Filtering - Supercharged Vehicles
Ai
r is supplied to the supercharger via an
intake cleaner/duct, throttle assembly and intake elbow which are similar to those
used for normally aspirated engines. The su percharger delivers pressurized air to two separate charge air cooler units, each
unit being mounted on the cy linder bank which it supplies. Pr essurized cooled air is fed from the charge air coolers directly
into each inlet port.