1998 JAGUAR X308 303

Default mode Definitions
MECHANIC
AL LIMP-HOME MODE:

No elec
tronic throttle operation (mechanical
operation for last quarter of pedal travel)
Ma
ximum 25° throttle opening,
depending on adjustment of th rottle mechanical linkage
Engine speed restri
cted to 3000
rpm maximum, by fuel cut-off
High i
dle 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 o
l inhibited
REVERSE THROTTLE PROGRESSION ENABLED:
Elec
tronic throttle operation, limited to maximum 25°
Cruise (speed) contr
o
l 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 restri
cted to 3000 rp
m maximum, by fuel cut-off.
Cruise (speed) contr o
l inhibited
LIMP-HOME UNAVAILABLE:
Cruise (speed) contro
l inhibited
Re

verse throttle pr
ogression engaged at second occurrence of DTC flagging
AmberRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P01 16,
P0117, P0118, P0125
Ambe
rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P01 01,
P0102, P0103, P0104
Ambe
rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P03 00,
P0301, P0302, P0303, P0304, P0305,

P0306, P0307, P0308, P1313, P1314
Ambe rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P03 27,
P0328, P0332, P0333, P1648
Ambe
rRestri
cted
Performance
R e
verse throttle pr
ogression enabled
P1474
AmberRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P1230
Ambe rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P1671
Ambe rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P11 12,
P1113
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1601 (SC on
ly)
AmberRestri
cted
Performance
Gearbox defau l
t to 4th gear
P16
05 (
NA only)
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P0702
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1795
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1796
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1797
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1605
Ambe
rNoneGearbox defau l
t to 4th gear
P0705 (SC on
ly)
AmberNoneGearbox defau l
t to 4th gear
P0706
Ambe
rNoneGearbox defau l
t to 4th gear
P1720

Diagnostic Trouble Code (D
TC) index
D
iagnostic Trouble Code (DTC) Index
DT

C
De
scription
Possib
le Source
Acti
on
P0300Ran

dom misfire detected
ECM t
o ignition coil primary circuit
faults (cylinder misfire detected
DTCs also logged)
Ignition coil
ground circuit; open
circuit, high resistance
F
uel injector circuit fault(s)
(injector DTCs also logged)
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
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

Actions)
W
orn camshaft/broken valve
springs
For ign
ition system tests,GO
to Pinpoint Test A.
. For
inje
ctor circuit tests,
REFER to: Fuel Charging and
Controls (30
3-04 Fuel
Charging and Controls,
Description and Operation).
Check compressions. For
spark plug tests,GO to
Pinpoint Test B.
.
Check fuel
pressure,
REFER to: Fuel System
Pressure Check (31
0-00 Fuel
System - General
Information, General
Procedures).
For fuel injectors,
REFER to: Fuel Charging and
Controls (30
3-04 Fuel
Charging and Controls,
Diagnosis and Testing).
For fuel tank and lines
information,
REFER to: Fuel Tank and
Lin
es

(310-01 Fuel Tank and
Lines, Description and
Operation).
Check PAS pulley bolt torque
(REFER to technical service
bulletins). For engine
information,
REFER to: Specifications

(3
03-01 Engine,
Specifications).
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
P0351Igni

tion coil primary/secondary circuit
malfunction, cyl 1
ECM to
ignition module primary
circuit open circuit, short circuit to
ground, high resistance
Igni
tion 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
failure
Ignition modul

e failure
F
or ignition circuit tests,GO to

Pinpoint Test A.
.
P0352Igni
tion coil primary/secondary circuit
malfunction, cyl 3
P0353Igni
tion coil primary/secondary circuit
malfunction, cyl 5
P0354Igni
tion coil primary/secondary circuit
malfunction, cyl 7
P0355Igni
tion coil primary/secondary circuit
malfunction, cyl 2
P0356Igni
tion coil primary/secondary circuit
malfunction, cyl 4
P0357Igni
tion coil primary/secondary circuit
malfunction, cyl 6
P0358Igni
tion coil primary/secondary circuit
malfunction, cyl 8
P1313Misfire rate
catalyst damage, Right-hand
cylinders. NOTE. This DTC will flag only
when accompanied by a random or
individual cylinder misfire DTC; P0300,
R
efer to possible causes for P0300-P0308
R
efer to actions for P0300-
P0308.

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 - 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.

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.

E
vaporative Emissions - Evaporative Emissions
D
iagnosis and Testing
Prelim

inary Inspection
1.
1. Vis
ually inspect for obvious signs of mechanical or electrical damage.
V
isual Inspection Chart
2.
2. If
an obvious cause for an observed or
reported concern is found, correct th e cause (if possible) before proceeding
to the next step.
3. 3. If the concern is not visually evident, verify the symptom and proceed with diagnosis, using the Jaguar approved
diagnostic system, where available.
4. 4. Where K-Line or Vacutec equipment is available, it should be used as an aid to diagnosis. The equipment must be
capable of testing to the 0.020 thou standard (2001 MY on).
Diagnostic Drive Cycles
Following th
e setting of a DTC, the appropriate repairs must
be carried out, and the normal operation of the system
checked. This will be done by performing a series of drive cycles which will enable the vehicle to operate the evaporative
emissions system as a function check. For details of the drive cycles,
REFER to Section 303
-1
4 Electronic Engine Controls
.
ECM adapt
ations.
Diagnostic Trouble Code
(D
TC) index/Symptom Chart
1.
1. Wh
ere 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).
2. 2. 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.
3. 3. 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.
CAUTION: 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.
MechanicalElectrical
Engi
ne oil level
Coo

ling system coolant level
Fue

l level
Fuel contaminatio
n
/grade/quality
Throttle body Poly

-vee belt
F
uses
W

iring harness
E

lectrical connector(s)
Sens

or(s)
Engine

control module (ECM)

Driver Info
rmation
•

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: A trip is an ignition OFF, 30 seconds delay, ignition ON cycle, plus a minimum coolant temperature increase of 22°
C (40°F) after which the coolant temperat ure should reach a minimum 71°C (160°F)
Diagnostic Trouble C
ode (DTC) index
Sy
m
ptom
Possib
l
e Source
Acti
o
n
D
i
fficulty in filling
R
e
striction in the vapor line between the fuel tank and the
carbon canister outlet/atmospheric port
Check f or free f
low of air.
F
u
el smell
Adaptat
i
ons incomplete
Cani
st
er purge valve inoperative
Carry
o
ut the adaptations
procedure,
REFER to Section 303
-14 Ele c
tronic Engine Controls
.
Chec k cani
ster purge valve
operation.
M e
ssage center display

(see below)
Fue l
filler cap missing/not
tightened after refuelling
Check fu
el filler cap condition
and fitment.
Warning Li
ght
Mess
age Defaul
t Mode
DT
C
RedCheck Engine (after two
trip
s)
ECM de
fa
ult (canister purge inhibited, adaptive fuel
metering inhibited)
P0442,
P0444, P0445,
P0447, P0448.
Re dCheck Engine (after two
trip
s)
No
neP04 52,
P0453.
Di
agno
stic
Trouble Code
De scr
iption
Possib
l
e Source
Acti
o
n
P0442Sy
st
em leak detected
F
u
el tank filler cap seal defective
Sy
ste
m leak (c
anister damage,
pipework damage)
Cani st
er close valve leaking
F
u
el tank leak
Chec
k fi
ller cap,
system pipework,
fuel tank,GO to Pinpoint Test A.
.
F o
r fuel tank information,
REFER to Section 310
-01 Fu
el Tank

and Lines.
P0444Canist
er purge valve circuit
open circuit
Cani st
er purge valve to ECM
drive circuit; open circuit, high
resistance
Cani st
er purge valve failure
F
or purge
valve circuit tests,GO to
Pinpoint Test B.
.
P0445Canist
er purge valve circuit
short circuit
Cani st
er purge valve to ECM
drive circuit; short circuit to ground
Canist
er purge valve failure
(stuck closed)
F or purge
valve circuit tests,GO to
Pinpoint Test B.
.
P0447Canist
er close valve (CCV)
circuit open circuit.
CCV power su pply ci
rcuit; open
circuit, short circuit
CCV to ECM drive circuit;
open
circuit, high resistance, short circuit to B+ voltage
CCV failure
Fo
r CCV circuit tests,GO to Pinpoint

Test C.
.
P0448Canist
er Close Valve (CCV)
circuit short circuit
Cani st
er close valve to ECM drive

circuit; short circuit to ground
Cani st
er close valve failure
F
o
r CCV circuit tests,GO to Pinpoint

Test C.
.
P0452 Fu
el tank Pressure (FTP)
sensor circuit; low voltage (low pressure)
FTP sen
sor disconnected
FTP sen

sor to ECM sense circuit;
open circuit, short circuit to ground
FTP sens
or to ECM power supply
circuit open circuit, short circuit to ground
FT
P sensor failure
For FT
P se
nsor circuit tests,GO to
Pinpoint Test D.
.
P0453Fu
el tank Pressure (FTP)
sensor circuit; high voltage
(high pressure)
FTP sen
sor to ECM signal ground
circuit open circuit
F T
P sensor to ECM wiring
(supply, sense, signal ground),
short circuit to each other
FTP sen
sor to ECM sense circuit
short circuit to B+ voltage
For FT P se
nsor circuit tests,GO to
Pinpoint Test D.
.
FT
P sensor failure
Sym
ptom Chart

generates a signal when th
e dr
ive plate passes the sensor
sen
ds the ECM signals indicating crankshaft position and engine speed
is e

ssential for calculating spark timing
En

gine Coolant Temperature (ECT) Sensor
sen
ds the ECM a signal indicating the temperature of the engine coolant
is a t

emperature dependent resistor with a negative temperature coefficient (resistance changes inversely with
respect to temperature) and is constantly monitored by the ECM
Intake Air Temperature (IAT) Sensor

is m
ounted in the same housing as the MA
F sensor but is not a serviceable item
sen
ds the ECM a signal indicating the temperature of the air entering the engine
is a t

emperature dependent resistor which has a negative
temperature coefficient (its resistance changes inversely
with respect to ambient temperature).
Knock S
ensor (KS)
is a pi
ezo-electric device which sends a signal
to the ECM indicating engine detonation
Between 700 and 6800 rpm, the ECM will retard individual cylinder ignition timing when detonation occurs while allowing
the other cylinders to continue operating normally.
During acceleration, at critical load and speed conditions, the ECM retards ignition timing to prevent the onset of detonation.
H
eated Oxygen Sensor (HO2S)
are
positioned upstream of the catalytic convertor
is equipped with

a heating element wh
ich improves the response time of the sensors during engine warm-up
h
as the ability to generate a voltage signal proportional to the oxygen content of the exhaust gases leaving the
engine
pr
ovides feedback information to the ECM used to calc
ulate fuel delivery and provide optimum gas emissions
Variable V
alve Timing (VVT) Solenoid
R
efer to section 303-01.