1998 JAGUAR X308 ESP

•
NOTE: For convenience, pinpoint test il
lustrations indicating voltage measurements do not always accurately reflect the
conventional method of connecting a multimeter. More explicitly, if the multimeter probes are connected as shown in some
illustrations (positive probe to ground), the voltage reading would be preceded by the negative sign '-', indicating that the
probes have been connected in the reverse manner to the norm al convention. The accuracy of the reading is not affected
and the '-' sign can be ignored when comparing the reading with the results indicated in the text of the pinpoint test.
Removal and Installation
Re
moval procedure(s), formatted
in the recommended sequence
Il
lustrated guide to the use of special tools
Il

lustrations to support the relevant text
Installation

procedure as above and including special re
commendations for processes, lubricants and tightening
torques.
Cir
cuit Diagrams
To
understand the relationship between the vehicle electric
al system and the system circuit diagrams, refer to the
appropriate Electrical Guide.
Fault Identificatio
n (DTC)
The diagnostic trouble codes (DTCs) are
li
sted in Section 303-00 under Diagno
stic Trouble Codes and include, where
applicable, the corresponding manual section reference.

High
tension (electrical)
ht
Hourh
Hydro

carbon
HC
I
Idl

e Air Control
IACEl
ectrical control of throttle bypass air
Idl

e Air Control Valve
IACVStepper motor dri
ven device which vari
es the volume of air by-passing the
throttle to maintain the programmed idle speed
Ignitionign
Ignition am
plifier
IAD
evice which amplifies the i
gniti
on system output
Ignition groundIGN GND
In

ertia Fuel Shut-off
IFSAn
inertia system that shuts off the fuel supply when activated by pre-
determined force limits brough t about by (e.g.) collision
In
ertia Fuel Shut-off
Switch
IFSSShut
s down fuel and ignition systems in the event of a vehicle impact
Inta

ke air
Air drawn t
hrough a cleaner and distri
buted to each cylinder for use in
combustion
InputI/PAn
electrical input signal to a controlling device
Inta

ke Air Temperature
IATTem
perature of intake air
Inta

ke Air Temperature
Sensor
IATSDe
vice used to measure IAT
Inta

ke Air Temperature
Sensor Ignition
IATSITherm
istor which signals the ECM to retard
the ignition timing in response to
high inlet air temperatures
Inta
ke Air Temperature
Sensor Injection
IATSFTher
mistor which inputs air density information to the ECM
Internal diameteri.

dia
Inte

rnational Standards
Organization
ISO
K
Kilogramme (mass)kg
Kilogram
me (force)
kg
f
Ki

logramme force per
square centimeter
kg
f/cm2
Kilom

eter
km
Ki

lometer per hour
km
/h
Kilopasc

al
kP
a
KilovoltkV
Knock

Sensor
KSSens
or which detects the onset of detonation, and signals the ECM to retard
the ignition
L
Le
ft-hand
LH
Left-hand drive veh

icle
LHD
Le

ft-hand thread
LH Thd
Ligh

t Emitting Diode
LEDLigh
t-emitting semiconductor diode used
in alphanumeric displays and as an
indicator lamp
Liqu
id Crystal Display
LCDOp
tical digital display system, applied voltage to which varies the way the
crystals reflect light, thereby modifying the display
LiterL
Low ten
sion
ltPrim
ary circuit of the ignition system, linking the battery to the primary
winding in the ignition coil
M
Malfu
nction Indicator
Lamp
MILA
required on-board indicator to aler
t the driver of an emission related
malfunction
Mani
fold Absolute
Pressure
MAPAbsolute pressure o
f the intake manifold air
Mani

fold Absolute
Pressure Sensor
MAPSSensor loca
ted in the ECM and
ported to the intake manifold
Manifol
d Surface
Temperature
MST
Mass Ai
r Flow
MAFSy
stem which provides inform
ation on the mass flow rate of the intake air to
the engine
Mass Ai
r Flow Sensor
MAFSHot-wi
re sensor which monitors air flow
into the intake manifold for fueling
and ignition control
Maxim
um
max.

Identification
Codes -
Identification Codes
Descr
iption and Operation
En

gine Number
The en
gine number (10 digits) is stamped on a raised pad on th
e front of the engine block near the thermostat housing. The
piston grade reference (8 digits) is also shown.
Automatic Transmission
Number
The
serial number of the transmission unit is displayed on
a metal or bar code label attached to the LH side of the
transmission casing.
Veh
icle Identification
Dependent
upon market, the VIN and other info
rmation is displayed on a label located ei ther on the rear edge of the LH front
door or on the body front upper crossmember. For certain mark ets, the VIN appears on a bar code label referred to as the
Certification Label and additionally carries the month and year of manufacture, vehicle weight data and paint and trim codes.
The VIN is also displayed on a plate visible through the windshie ld. It is essential that the vehicle identification number (VIN)
is quoted when ordering parts, and in all associated correspondence.

ItemDe
scription
GVW

R
G
ross Vehicle Weight Rating
GAW

R F
Gros
s Front Axle Weight Rating
GAW

R R
Gros
s Rear Axle Weight Rating
Pai

nt
Pai
nt Code
TrimTrim

Code

Suspension System - General Information - Front Camber and Caster
Adjust
ment
Gen
eral Procedures
• NOTE: Before any work is commenced, th e vehicle must be checked to establish that it conforms to the Jaguar original
specification, e.g. wheels, ti res, tire pressures, etc.
• NOTE: The vehicle must be unladen and the fuel tank full when measuring suspension geometry.

1.
Road test the vehicle to establish the exact nature of the
complaint, e.g. pulling to one side, wander.
2. Measure the suspension geometry, fill in the 'Suspension
Geometry Record Form', and co ntact Jaguar Technical Support
for assistance.
3. Technical Support will give advice on the course of action to be
taken to rectify the problem.
4. Each lower wishbone pivots on and is secured to the front
crossbeam by two fulcrum bolts. A circular eccentric flange
formed under the hexagonal head of each fulcrum bolt, has
raised graduation marks to indicate radial position. A washer
with a 'D' shaped hole locates on a flat on the threaded section
of each bolt. This ensures that the washer rotates with the bolt,
maintaining an eccentric position corresponding with the
flanged head. The outer face of the washer is punch marked,
ensuring correct instal lation with the chamfered face inwards.
This permits the washer to rotate freely in the crossbeam cam
reaction plate during a djustm ent. Each fulcrum bolt and
washer are secured by a self locking nut.
On rotation of the bolt, lateral movement of the eccentric flange
and washer is restricted by the cam plate faces, forcing the bolt
shank to move laterally in the crossbeam slots. Lateral
movement of the bolt shank re sults in corresponding inward
and outward movement of th e wishbone arm, effecting
adjustment of wh eel alignment.
Rotation of the front fulcrum bolt principally adjusts wheel
caster angle, with a small amount of camber angle change.
Adjustment of the rear fulcrum bo lt mainly alters wheel camber
angle with a small amount of caster angle change.
On vehicles with VIN up to 833124, fulcrum bolt eccentric
flanges have raised graduation marks representing 15 degree
increments of bolt rotati on from 0 to 90 degrees.
On vehicles with VIN from 833125, the fulcrum bolt graduation
marks represent bolt shank ho rizontal movement in 1mm
increments from 0 to 3mm.
The upper wishbone and fulcrum shaft are not adjustable and
play no part in steering geometry adjustment.

Rear
Suspension - Rear Suspension
Description an
d Operation

Description
The i
ndependent rear suspension incorporates co-axial sp
ring and shock absorber units, a subframe, wishbone tie,
pendulum assembly, mounting brac ket, differential strut, cast wishbones and hub carriers. The suspension assembly is
positively located by the subframe, mounting bracket and differential strut.
Each wi
shbone pivots on a fulcru
m bolt which locates in the wishbone tie and pendulum assembly.
The wish
bone tie and pendulum assemblies are respectively in
stalled at the front and rear of the final drive housing.
The differential
strut is secured to the wishbone tie assembly.
Two ti

e rods are installed between the front of the
subframe and the top of the final drive housing.
The ou
ter extremity of each wishbone
is secured to its respective hub carrier assembly by a fulcrum bolt.
Each fulcrum bolt head incorporates an ec centric circular flange which locates in a groove in the front face of the wishbone
arm. Rotation of the fulcrum bolt results in horizontal movement of the bolt shank in an elongated hole in the rear of the
wishbone arm. This acti on achieves corresponding movement of the hub carrier, facilita ting adjustment of road wheel toe-
in.
It
em
Par
t Number
De
scription
1—Hub Carrier
2—Wi

shbone
3—Sprin

g
4—Shock Absorber
5—Suspensi

on Turret

6—Suspensi
on Subframe
7—Moun

ting Bracket
8—D

ifferential Strut
9—Stabilizer Ba

r (Supercharged and
Sport Suspension Models only)
10—Bum
p Stop

Each r
oad spring and is located between the wishbone in
tegral spring seat and the body suspension turret.
Each shoc
k absorber unit is installed
co-axially within the road spring.
The lo
wer end of each shock absorber is secured to the
wishbone by a bolt which also functions as a pivot.
Adaptive damping is av
ailable as an option.
A
rear stabi
lizer bar is installed on
Supercharged and Sport Suspension models . Mounted at the rear of the wishbone
tie assembly, the stabilizer bar is connected to the wishbone by short links.
Op era
tion
As each road wheel r
i
ses, move
ment is transmitted through th e hub carrier assembly to the wishbone and axle shaft. The
corresponding rise of the wishbone compre sses the road spring and partially telescopes the shock absorber. During this
action, the spring absorbs result ing shocks and the shock absorber minimizes spring oscillation.
During cornering, vehicle weight is transferred to the outer road wheel with a resulting tendency for the inner wheel to lift.
On Supercharged and Sport Suspension vehicl es, a rear stabilizer bar assists in minimizing this tendency by transferring a
proportion of potential lift of the inner wheel to the outer wheel. This results in enhanced body stability with improved
cornering capabilities.

I
nstallation


18
.
WARNING: With assistance, support the rear suspension
and axle assembly during remo val. Failure to follow this
instruction may result in personal injury.
Remove the rear suspensi on and axle assembly.
E
nsure that the hydr
aulic pipes, brake calipers, harnesses
and the drive shaft will not obstruct the rear suspension
and axle assembly during removal.
Carefull
y lower the rear suspen
sion and axle assembly and
traverse clear of vehicle.

19
.
Retrieve the subframe mounting bush shims.
20. With assistance, position th e rear suspension and axle
assembly on to a bench.
21. Clean the subframe mounting bushes and corresponding body
locations.

1. Apply a th
in coat of grease to the subframe bushes and place
the shims in position.
2. WARNING: With assistance, support the rear suspension

O
ne locking wheel nut is fitted to each road wheel and can on
ly be removed by using the correctly coded socket. For road
wheels with exposed wheel nuts, each locking wheel nut is provided with a cover, which is removed using the cover removal
tool.
Locking wheel nuts have different coded keyway combinations with corresponding coded sockets. The correct socket, and
cover removal tool are supplied with the vehicle toolkit. Sets of sockets are available to Jaguar dealers.
Temporary Spare Wheel
•
NOTE: When using this type of spare wheel note that:
Speed

must not exceed 80 km/h (50 mph).
The normal ro

ad wheel must be reinstalled as soon as possible.
On

ly one temporary wheel may be installed to the vehicle.
Tracti

on control (where fitted
) must be switched OFF.
In certain markets, the spare wheel supplied with the vehicle is of the temporary-use type, it is narrower than the normal
road wheel and takes up less room in the luggage compartment.
Tire
s
The
radial ply tires shown in the 204-04
Specification Section are recommended by Jaguar to meet the high speed
performance of the vehicle. Only tires of identical specification may be fitted as replacements. Unde r no circumstances must
cross-ply tires be fitted.
Tire Inflation Pressures
Al
l recommended tires, including winter tire
s, must be inflated to the pressures shown in the 204-04 Specification Section.
Inflation pressures must only be checked when the tires are cold.
Tire Replac
ement and Wheel-Interchanging
W
hen renewal of tires is necessary, it is
preferable to fit a complete set. If two replacement tires are fitted (to one axle),
they must be of the same manufacturer and type as those on the other axle.
No attempt must be made to interchange wh eels from the front to the rear or vice-versa, as wear produc es a characteristic
pattern on each tire depending upon its po sition on the vehicle. If this position is changed after wear has occurred, the
performance of the tire w ill be adversely affected.
It should be remembered that new tires must be balanced befo re installing to the vehicle.
Win
ter Tires
•
NOTE: Speed must not exceed 210 km/h (131 mph) when winter tires are installed.
Jaguar recommended winter tires as specified in 204-04 Specification Section must only be fitted in complete four-wheel
sets of the same type and size.
Snow Chains and Spike Spider Traction System

Jagu
ar recommended snow chains, must on
ly be installed when using 16 inch wheels with 255/60 R16 winter tires.
• NOTE: When using snow chains or the spike spider traction system, note that:
Snow ch
ains and the spike spider
traction system must only be fitted to the rear wheels.
O
nly Jaguar recommended snow chains and spik
e spider traction system must be used.
The m
aximum permissible speed with winter tires and snow chains or the spike spider traction system fitted is 48
km/h (30 mph).
Tracti
on control (where fitted) must be
switched OFF when using snow chains or the spike spider traction system.