1998 JAGUAR X308 bank 1

patc
hed fastener of the same specification fitted. All mating th
reads must be thoroughly cleaned prior to fitting of the new
fastener.
Jaguar Specification JFS 02.01.04 patched fasteners incorporat e a plastic/polyester on the thread. Acting as a wedge
between the mating threads, this compound imposes a prevaili ng torque during tightening. Whilst this type of patched
fastener can be re-used, the imposed torq ue diminishes. It is therefore recommended that following third removal, this type
of patched fastener is discarded and a new fast ener of the same specification is fitted.
Special fasteners bearing the following pa rt numbers are of the micro-encapsulated adhesive type and following removal,
must be discarded and replaced by ne w items of the same specification:
CAC 8223
JZB 10060; JZB 10061; JZB 10078.
JZH 100027.
JZS 100082; JZS100087; JZS 100088; JZS 100089; JZS 100090; JZS 100118; JZS 100157; JZS 100164; JZS 100166.
NCA 1451 AA.
Vehicle Specifications

Purchasers are advised th
at th
e specification details set out in this manual apply to a range of vehicles and not to any
specific one. For the specificatio n of a particular vehicle, purchasers should consult their dealer.
The Manufacturer reserves the right to vary the specifications, with or without notice, and at such times and in such manner
as the Manufacturer thinks fit. Major as well as minor changes may be involved , in accordance with the Manufacturer's
policy of continuous improvement.
Whilst every effort is made to ensure the accuracy of the pa rticulars contained in this manual, neither the Manufacturer nor
the Dealer, by whom the manual is supplied, shall in any circumstances be held liable for any inaccuracy or the
consequences thereof.
Serv
ice Repair Operation Numbering
A
master index of numbered operations has been compiled for
universal application to all vehicles manufactured by Jaguar
Cars Ltd.
Each operation is allocated a number from the master index and cross-refers with an identical number in the Repair
Operation Times schedule. The number consists of six digits arranged in three pairs.
Each maintenance procedure in this manual is described in the sequence necessary to complete the operation in the
minimum time, as specified in the Repair Operation Times schedule for this range of vehicles.
Re
ferences to Left- and Right-Hand
R
eferences to the left- or
right-hand side of the vehicle are made as if viewing from the driver's seat.
Ref
erences to Engine Banks
Wi
th the engine installed in the vehicle, the right-hand cylinder
bank is designated Bank A, and the left-hand cylinder bank
is designated Bank B.
Specia
l Tools
Any special too

ls and equipment required
to perform a maintenance procedure, are shown at the beginning of each
maintenance procedure.

Engine System - General Infor
mation - Engine
Description an
d Operation

The AJ26 power unit is available in 3.2 L and 4.0 L versions, and comprises:
An eight cylinder 9
0 degree 'V' config
uration liquid cooled aluminium cylinder block incorporating 'Nikasil' plated
cylinder bores.
Pi
stons of open-ended skirt design, with
two compression and one oil control ring.
Two al
uminium cylinder heads, each
incorporating two camshafts.
F
our valves per cylinder.
Al

uminium valve lifters and top mounted shims.
Vari

able valve timing (VVT) of the inlet camshafts (4.0 L normally aspirated only).
Camshaft

covers manufactured from Vinylester.
Al

uminium timing cover which accommodat
es the crankshaft front oil seal.
Sin
gle row primary and secondary chains dr
ive the camshafts of each cylinder bank.
An alu
minium bed pl
ate, incorporating iron main bearing supports, which accomm odate the oil pump pick-up,

Speed an
d load
Coo
l
ant temperature
Ti
me el
apsed from start up
Cl
osed l
oop fuelling
Determination of the vapour concentration is made by stepped opening of the EVAP valve and subsequent monitoring of the
fuelling correction. This function is performed prior to purging, so that at the onse t of purging the EVAP valve can be set to
the optimum position. Should the ECM be unable to determine the concentration before purging, a default value is
employed, which is then modified whilst purging is in progress.
When the purging process is operational th e ECM modifies the basic fuelling calculation to maintain the correct air / fuel
ratio.
Purging is inhibited during fuel cut-off and stability / traction control intervention.
Coolant Temperature Sen
sor
Th
e
sensor outputs a voltage to the ECM which decreases as temperature increases.
Cooling Fans


In response to engi
ne coolant temperat
u
re and climate control system demand, the ECM will energize the cooling fans.
Climate Control Compressor
The E
C
M will allow the compressor clutch to be engaged if th
e engine temperature and load demand are normal. Should the
driver require maximum engine powe r or the coolant temperature be high, the request will be denied.
Cranking Signal

The ECM reacts to a signal fr
om th
e Body Processor Module (BPM) when the starter motor relay is energi
zed. This signal is
used to trigger starting, fu el and ignition strategies.
Engine Speed and Cranksh
aft Position
Engine
speed and cran
k position are moni
tored by a sensor which is mounted on the cylinder block (flywheel housing)
behind the crankshaft drive plat e. It indicates rotational speed to the ECM in the form of 12 pulses per crank revolution.
Engine speed is used for synchronization of fuel an d ignition systems, as well as other functions.
Camshaft Position
The ca
mshaft position sensor is mounted at
the rear of Bank 2 cylinder head on the inlet side and provides one signal every
720 degrees of crankshaft rotation. The signal, in conjunction with the signal from the crankshaft position sensor, indicates
to the ECM that the piston of cylinder 1A is approaching TDC on the compression stroke.
Variable Valve
Timing (Where Fitted)
By energi
si
ng a solenoid to allow the pass
age of pressurized oil on each of the inle t camshaft drives, the ECM can vary by a
single stepped amount, the relati ve timing of the inlet valves.
Ign
ition
Ignit
i
on spark is produced by
individual on-plug coil units.
There are two ignition amplifiers; module #1 drives coils 1A, 2B, 3B and 4A, whilst module #2 drives coils 1B, 2A, 3A and
4B. The ECM controls the amplifiers.

Thi
s sensor uses a piezo-electric sensing element to detect kn
ock which may occur under acceleration at critical conditions.
Should detonation be present the ECM will retard ignition timing of individual cylinders.
Exhaust G
as Recirculation
The EGR
valve (where fitted) reduces NOx
emissions by recirculating a portion of the exhaust gases back into the inlet
manifold.
Heated Oxyg
en Sensors
The h
eated oxygen sensors, one per bank, are situated upstream of the catalysts. Integral
to the sensors are heaters
(under ECM control) which allow the sensor s to reach their operating temperature as soon as possible after engine start. A
comparison between the level of oxygen in the exhaust gas to that in the atmosphere produces an output signal. This signal
is used by the engine closed loop fuel strategy to make fuelling corrections and so control overall emission levels.
Oxygen Sensors

Thes
e sensors, one per bank, are situated downstream of the
catalyst. The comparison of upstream and downstream signals
allows determination of cata lyst conversion efficiency.




Knock Sensor

En
gine - Engine
D
iagnosis and Testing
Sym

ptom Chart
Sy
mptom Chart
Pinp

oint test A: P1392 (P1397)
VVT solenoid circuit low input
S
pecial Tool(s)

D

igital multimeter

Generi

c scan tool
Sy

mptom
Possib
le Sources
Acti
on
D

TC P1392 VVT solenoid A circuit low input
So
lenoid coil open circuit
Harness open circuit or blown fuse
Connector pins(s) bent , loose or corroded
*
*
*
GO to
P
inpoint Test A

*
D
TC P1397 VVT solenoid B circuit low input
So
lenoid coil open circuit
Harness open circuit or blown fuse
Connector pins(s) bent , loose or corroded
*
*
*
GO to
P
inpoint Test A

*
D
TC P1393 VVT solenoid A circuit high input
So
lenoid coil short circuit
Harness short circuit
Connector pins(s) bent , loose or corroded
*
*
*
GO to
P
inpoint Test B

*
D
TC P1398 VVT solenoid B circuit high input
So
lenoid coil short circuit
Harness short circuit
Connector pins(s) bent , loose or corroded
*
*
*
GO to
P
inpoint Test B

*
D
TC P1396 VVT solenoid B malfunction
O
il pressure failure
VVT solenoid sticking
Connector pins(s) bent , loose or corroded
Crankshaft position sensor failure
ECM failure
*
*
*
*
*
GO to
P
inpoint Test C

*
P
INPOINT TEST A : P1392 (P1397) VVT SOLENOID CIRCUIT LOW INPUT
•
NOTE: References in brac
kets are for Bank B (2)
T
EST CONDITIONS
D
ETAILS/RESULTS/ACTIONS
A1

: RETRIEVE DTCS
•

NOTE: Battery and or ECM disconnection prior to scanning wi
ll erase all data, ensure that the correct DTC is present.

W
ith VVT connector PI031 - A bank or (PI032 - B bank)
disconnected, measure the resistance between the pins 1
and 2 at the VVT actuator
1
I
s the resistance less than 5
OHM or greater than 20 OHM?
Yes Renew the VVT solenoid and te st the system for normal
operation.
No GO to A4
A4: CHECK
HARNESS CONTINUITY

Pin
point test B: P1393 (P1398) VVT solenoid circuit high input
W
ith EM014 disconnected, measure the resistance
between EM014/009 and ground EM016L
1
I
s the resistance < 0.5 OHM?
Yes Reconnect EM014, EM015, PI031 or (PI032)
GO to A6
No Inspect harness / connector EM014, ground stud and
splice EMS37 for corrosion, damage, bent or pushed back
pins and repair as required. Test the system for normal
operation.
A6
: END
Perform

appropriate service drive cycle and check for the
presence of DTC.
1
Has
the fault code cleared?
Yes STOP
No Contact Jaguar Service
P
INPOINT TEST B : P1393 (P1398) VVT SOLENOID CIRCUIT HIGH INPUT
•
NOTE: References in brac
kets are for Bank B (2)
T
EST CONDITIONS
D
ETAILS/RESULTS/ACTIONS
B1

: RETRIEVE DTCS
•

NOTE: Battery and or ECM disconnection prior to scanning wi
ll erase all data, ensure that the correct DTC is present.

Connect
the scan tool
1
Have the DTC(s) and fr
eeze f
rame data been recorded?
Yes GO to B2
B2 : CH
ECK VVT COIL CONTINUITY
W
i
th VVT connector PI031 - A bank or (PI032 - B bank)
disconnected, measure the resistance between the pins 1
and 2 at the VVT actuator
1
I s
the resistance >20 OHM?
Yes Renew the VVT solenoid and te st the system for normal
operation.
No GO to B3
B3: CHECK
SHORT TO B+