1994 JAGUAR XJ6 Diagnostic

Suspension Systems
1 1.4.8 Diagnostic Procedure
Condition
Hard steering
Shimmy
I----
Bump steer (unequal
side-to-side)
Sawtooth pattern or
t excessive tire wear
Uneven tire wear
(outer or inner
shoulder)
Fronvrear
suspension noises
Possible Cause
Side-to-side difference in caster.
Tire pressure Steering gear or linkage worn or defective.
Tire
conicity
Power steering gear or linkage worn,
damaged, or incorrect adjusted.
Wear of front suspension
lower/upper
wishbone ball joints.
Unequal tire pressure.
Brake system
fault(s)
Wheel/tire imbalance or runout.
Damaged tires, unbalanced or damaged
wheels.
Incorrect wheel alignment.
Steering system malfunction
Front damper malfunction.
Loose front damper mounting.
Damaged front suspension upper
or lower
ball joints.
Damaged or worn sub
-frame to body
mounting. Damaged or worn stabilizer bar insulators.
Damaged or worn stabilizer bar link.
Damaaed or worn wheel bearina.
Rear suspension damage.
Worn steering gear mounting bracket
housing insulators.
Excessive toe
-in (high edges inboard) or
toe-out (high edges outboard).
Incorrect tire pressure.
Excessive toe.
Excessive positive or negative camber.
Loose/missing front dampers and front
damper bolt to front suspension lower
wish bone.
Action
Check the alignment and if incorrect,
adjust the caster
if needed. Inspect
components for wear or damage.
Check for abnormal loading.
Check steering system
Inspect tire for excessive wear.
Check and adjust the tire air pressure.
Note: Excessively worn or uneven tires can
cause
pull/drift.
Check steering system.
Renew ball joints.
Inflate the tires to correct and uniform
pressure.
Check the brakes.
Check wheels and tires.
Check the tires and renew
if necessary.
Balance the wheels
if necessary.
Adjust wheel alignment.
Check steering system.
Renew front damper
if necessary.
Tighten front damper mounting.
-
Renew upper and lower ball joint.
Renew rear suspension bushing.
Renew insulators.
Renew link.
Renew/adjust wheel bearing.
If the caster is uniform, check and compare
the wheelbase at the right and left sides.
If
different, inspect the suspension
components for wear and damage.
Renew bracket housing insulators.
Check and adjust toe
-in.
Correct tire pressure.
Check toe and adjust
if needed.
Check the camber and
if incorrect inspect
the related components for wear or
damage.
Tighten/renew damper bolts.
Inspect wheel hubs.
0
0
0
lssue 1 August 1994 6 X300 VSM

Suspension Systems I.\" b-
1 1.4.8 Diagnostic Procedure (continued)
Condition
30dy 'rolls'
3ody leans
'oor ride comfort
Seneral driving
nstability
Steering wheel does
lot return properly
Steering wheel pulls
:o one side
4bnormal noise
from suspension
system
Possible Cause
Weak front stabilizer bar.
Damaged or worn lower wishbone stabilizer
bar insulator. Damaged or worn stabilizer bar link
Damaged or worn rear suspension
wishbone bushing.
Damper malfunction.
Worn or deteriorated rear stabilizer bar
bushing(s). (supercharged, sports and XJ12
only)
Damaged or worn rear wishbone bushing
and weak springs.
Worn or deteriorated rear stabilizer bar
bushing(s). (supercharged, sports and XJ12
only)
Front or rear damper malfunction.
Weak
spring(s1
Damaged tires or unbalanced wheels.
Incorrect wheel alignment.
Steering system malfunction.
Damaged front suspension lower and upper
ball joints.
Damaged or worn sub
-frame to body
mounting.
Damaged or worn stabilizer bar link
Damaged or worn lower wishbone stabilizer
bar insulator.
Weak
spring(s)
Worn or deteriorated rear stabilizer bushing
(s). (supercharged, sports and XJ12 only)
Damaged tires or unbalanced wheels and
incorrect tire pressure.
Incorrect wheel alignment.
Steering system malfunction.
Damaged front suspension lower and upper
ball joints.
Incorrect tire pressure.
Damaged front suspension lower and upper
ball joints. Braking system malfunction.
Steering system malfunction.
Damaged or worn sub
-frame to body
mounting.
Damaged tires, unbalanced wheels and
incorrect tire pressure.
Poor lubrication /wear of wheel bearing.
Wear of front suspension lower and upper
ball joints.
Damaged or worn front stabilizer bar
Damaged or worn stabilizer bar link.
Damaged or worn stabilizer bar bracket.
Looseness of suspension connections.
Damaged or worn rear wishbone bushing.
Front and rear damper malfunction.
Weak
spring.Worn or deteriorated rear
stabilizer bushing
(s). (supercharged, sports
and
XJ12 only)
Action
3enew front stabilizer bar.
3enew insulators.
3enew link.
Renew bushing.
Renew damper
if necessary.
Renew Bushina
Renew bushings and springs.
Renew Bushings.
Renew dampers.
Renew springs.
Check the tires.
Adjust the wheel alignment.
Check steering system.
Renew ball joints.
Renew bushing.
Renew link.
Renew insulator.
Renew springs.
Renew bushing
Check tires.
Adjust the wheel alignment.
Check steering system.
Renew ball joints.
Check and correct tire pressure.
Renew ball joints.
Check brakes.
Check steering system.
Renew bushing.
Check tires.
Renew wheel bearing.
Renew ball joints.
Renew stabilizer bar.
Renew link.
Renew bracket.
Tighten connections.
Renew bushing.
Renew dampers.
Renew bushing
Issue 1 August 1994 X300 VSM 7

12.1 ANTI-LOCK BRAKING SYSTEM (ASS), GENERAL DESCRIPTION
The anti-lock braking system (ABS) components are combined with a hydraulic booster and tandem master cylinder (TMC) to provide a two-circuit braking system. The anti-lock braking system comprises the following components:
0 Four inductive wheel speed sensors, hub end mounted
0 ABS warning light
0 Hydraulic module.
The hydraulic module consists of an electric motor driven pump,
two low pressure accumulators, valve block and an
ABS electronic control module.
m: Electronic control modules for vehicles without traction control are designated ABS CM. Control modules for
vehicles with traction control are designated ABS /TC CM.
The valve block houses solenoid operated valves which are activated by voltage signals from the control module. The
signals are generated using wheel speed information received from the wheel speed sensors.
For vehicles without traction control the valves operate on three circuits, two front and one rear, as necessary to pre
- vent wheel locking during braking. Brake pressure is modulated individually at thefront wheels and collectively at the
rear. Rear wheel control operates on a 'select low' principle i.e. locking in either wheel is sensed, and controlled brake
pressure is applied to both wheels.
For vehicles with traction control the valves operate on four circuits. During ABS control the rear wheel are controlled
on a 'select low' principle (as above), but during traction control operation the rear wheels are controlled individually.
0
1yQfB: Functional and diagnostic information for the ABS CM and the ABS/TC CM is contained in the Electrical Diag-
nostic Manual (EDM), Section 12.
ABS Warning lamp / Traction Control Warning lamp /Fluid level Indicator
The ABS and traction control warning lamps, mounted in the instrument panel, indicate a fault in the ABS or traction
control. These systems are inhibited or disabled when the lamps are lit, although conventional braking is unaffected.
When the ignition is switched on, an ABS self test is initiated. During this test, the ABS and traction control warning
lamps are
lit for approximately 1.7 seconds and then extinguish. A fault is indicated if the warning lamps remain lit or
come on whilst the vehicle is being driven.
W: The ABS self test is masked by the 5 second lamp test initiated when the ignition is switched on.
The fluid level indicator lamp, mounted in the instrument panel, is
lit when the brake fluid falls below the minimum
mark on the brake fluid reservoir.
ABS / Traction Control - Inhibit / Disable
Faults conditions are detected by the ABS/TC CM which disables the ABS and traction control until the fault is rectified.
The ABS and traction control warning lights on the instrument pack remains lit whilst a fault exists. The system will
be disabled when the following conditions occur:
0
0 Valve failure
0 Sensor failure
0 Main driver failure (internal ABS /TC CM fault)
0 Redundancy error (internal ABS JTC CM fault)
0 Overvoltage J undervoltage
0 Pump motor failure.
0 Throttle valve actuator motor failure (traction control vehicles only).
0 Throttle valve actuator potentiometer failure (traction control warning light only).
X300 VSM 1 Issue 1 August 1994

The input frequency from each wheel speed sensor signal is translated by the ABS I TC CM, into a comparable wheel
speed. The ABS / TC CM continually monitors the system. False wheel speed information, such as sudden speed
changes in excess of 20 km / h or excessive speeds, are detected as a 'sensor malfunction'. The ABS / TC CM reacts
to fault conditions in the following ways:
Inhibit- ABS/traction control is inhibited until the sensed speed returns to within an acceptable limit, whereupon ABS
/traction control is restored. Conventional braking is unaffected. Depending on vehicle speed the ABS/traction control
warning lights may come on.
DisaMe - ABS /traction control is Disabled (switched off) and the ABS /traction control warning lights come on. The
system will not be restored until the engine is switched off and restarted orthe fault has been rectified. Afterthe system
has been disabled, the warning lamps remain on until the vehicle has reached a speed of 20 km/ h during thefirst igni- tion cycle after fault rectification.
Full diagnostic information for the ABS /TC
CM is given in the Electrical Diagnostic Manual (EDM), Section 12.
Issue 1 August 1994 2 X300 VSM

12.1.5. ABS Components
Hydraulic Module
The hydraulic module is located under the bonnet adjacent
to the engine compartment firewall. It is secured within a steel mounting bracket at three securing points. All elec- tronic and power connections are made through one cable
loom connect ion.
The hydraulic pump
(1 Fig. 1) is a reciprocating two-circuit pump in which one brake circuit is assigned to each pump
circuit. The pump supplies adequate pressure and volume
supply to the brake circuits under anti
-lock braking condi- tions. The pump is driven by and electric motor (2 Fig. 1). The
pump housing incorporates two low pressure accumulators
and damping chambers for each brake circuit.
A modulator valve block
(3 Fig. 1) incorporates the ABS CM or ABS / TC CM (4 Fig. 1). Vehicles with traction control are
fitted with a throttle position actuator (5 Fig. I), which is an
electrical device controlled by the ABS 1 TC CM.
Valve blocks on vehicles without traction control comprise
six solenoid valves, three normally open (NO) inlet valves
and three normally closed
(NC) outlet valves. These valve
blocks have three outlet ports. Valve blocks on vehicles with
traction control comprise nine solenoid valves, four
NO inlet valves,four NC outlet valves and one special isolating valve.
Fig. 2 shows a hydraulic module for vehicles with traction
control. The valve block (2 Fig. 2) has four outlet ports (Indi- vidual control of the driven wheels).
A BS CM, A BS / TC CM
The ABS CM or ABS TCI CM locates beneath the modulator
valve block and is secured by
two screws. The CM houses
the solenoids which operate the inlet and outletvalves of the
modulator valve block. When fitted, the valve stems locate
in the
CM mounted solenoids. There is no electrical connec- tion between the CM and the modulator valve block. Fig. 3 shows an ABS TC 1 CM having nine solenoids.
The
CM functions include the following:
0 Providing control signals for the operation of ABS
and traction control solenoid valves
0 Calculating wheel speed from voltage signals trans- mitted by the wheel speed sensors
0 Monitoring of all electrical components
0 On Board Diagnostics (OBD): storage of possible fail- ures in a non-volatile memory.
The signals from the four wheel speed sensors are indepen
- dently processed by the ABS CM or ABSITC CM, calculating
numerical values which correspond directly to the wheel
speed. These values are converted into control signals for
pressure modulation during ABS control.
The ABS and traction control
are continuously monitored,
whilst the ignition is on,for possiblefaults and interruptions.
If a fault is detected, the module deactivates the ABS and
indicates this by lighting the ABS warning lamp. In a fault
condition, conventional braking is unaffected. The module
stores fault codes in a non
-volatile memory which can be
read via the OBD link.
U: For electrical diagnostic information on the ABS I traction control systems, refer to EDM, Section 12. Fia.
1
Fia. 2
Fin. 3 I
J70286
Issue 1 August 1994 X300 VSM

Body Components & Trim
13.1 GENERAL DESCRIPTION
This section covers the following areas of the vehicle body:
0 Battery cover
0 Carpets - passenger compartment, trunk
0 Console - including radio, glovebox
0 Doors -frames, sealing, locks, trim, glazing
0 Fascia
0 Fuel filler flap assembly
0 Footrest
0 Hood - liners, gas strut, locking,
0 Illuminated sunvisor - inc mirror
0 Interior trim - trim pads, finishers, veneers
0 Mirrors - internal, external
0 Rear parcel tray
0 Roof console
0 Roof lining (headlining)
o Seats -front, rear -
0 Seat belts - front, rear
0 Sliding roof
0 Steering column cowl
0 Underscuttle pad
Refer to Appendix
A4 - Body Systems & Body Repair for information relating to crash-damage repairs and to the fol- lowing external components: exterior trim, bumpers, windscreen and rear screen, closures and sealing.
Refer to Section 15, Electrical for details of the following motors and solenoids: driver's and interior mirrors, window
lift, sunroof, seat / headrest and locking mechanisms (doors, trunk and filler cap).
Refer to Section 15, Electrical and Electrical Diagnostic Manual (EDM) for details of the passenger and driver airbags.
X300 VSM 1 Issue 1 August 1994

Body Components & Trim d-!P
13.2
13.2.1 Doors, Description
Doors are of welded, mild steel frames welded to the door panels; sponge rubber primary and secondary seals are
mounted on the doors. Internal insulation is provided by a foam water shedder attached to the door by press fitting and doublesided adhesive tape.
Front and rear door armrests are attached to supports riveted to each door frame; the attaching screws are fitted
with access covers. Upper and lower trim pads and a door pocket are attached to each of the doors by clips and screws. multi-plug connectors are used to provide a means of connecting the guard lamps, window lift switches and loud- speakers, external mirror and regulator (front doors only), which are housed within the doors.
Central locking is provided subject to market variations: Dead Locking for UK
/ Europe and Driver only unlock for N America. Door locks are eight disc, bayonet fixing, barrels with integral lock / unlock switches. Keys include ‘in-key’
transponders which are programmed to the vehicle via the Jaguar Diagnostic System also operate the engine immobi
- lisation system.
CAUTION: When removing the door panel water shedder, a foam membrane attached to each door panel by a com- bination of pressfitting (upper area) and bydouble-sided tape (bottom area), it is important that the shed- der is refitted correctly to maintain the water seal.
It is advisable not to disturb the bottom (taped) portion of the water shedder unless absolutely necessary
- it is possible to unclip the top of the shedder and bend it over to gain access to the inner panel.
If
it is necessary to disturb the bottom attachment, eg to remove the water shedder from the door panel,
the existing water shedder must be discarded and a new one fitted to ensure that the seal is maintained.
On refitting, the new water shedder should be pressed onto the door panel at the top and then the adhes- ive tape backing strip peeled off to enable the shedder to be pressed home at the bottom.
DOORS AND FUEL FILLER FLAP
13.2.2 front and Rear Door Trim Pad Veneer Panel,
Renew
SRO 76.47.11
76.47.12
. Reposition the inner door handle. See Fig. 1.
Remove the inner handle escutcheon plate blanking plate.
Undo and remove the inner handle escutcheon plate se-
. Remove the plate and gasket.
. Carefully Undo and remove the veneer panel.
Undo and remove the retaining clip securing screws.
. Remove the retaining clip assemblies.
9 Place the veneer panel aside.
Place the new veneer panel to the front.
Fit the retaining clip assemblies.
. Fit and tighten the retaining clip securing screws.
. Fit and fully seat the veneer panel to the door.
. Reposition the inner door handle.
. Fit the gasket and plate over the inner door handle.
. Fit and tighten the escutcheon plate securing screw.
. Refit the blanking plate.
curing
screw.
Fig.
1
0
0
0
0
Issue 1 August 1994 2 X300 VSM

Climate Control Systems
0 Because HFC 134A is fully recycleable it may be 'cleaned' by the recovery equipment and re-used following
removal from a system.
0 Leak tests should only be carried out with an electronic analyzer which is dedicated to HFC 134A. Never use a CFC 12 analyzer or naked flame type.
0 Do not attempt to 'guess' the amount of refrigerant in a system, always recover and recharge with the correct
charge weight. In this context do not depress the charge or discharge port valves to check for the presence of
refrigerant.
14.1.3 Handling Lubricating Oil
0 Avoid breathing lubricant mist, it may cause irritation to your respiratory system.
0 Always decant fresh oil from a sealed container and do not leave oil exposed to the atmosphere for any reason
other than to fill or empty a system. PAG oil is very hygroscopic (absorbs water) and will rapidly become con-
taminated by atmospheric moisture.
PAG oil is
NOTcompatible with previously used mineral based oils and must NEVER be mixed (Fig. 1). Do not
re
-use oil when it has been separated from refrigerant, following a recovery cycle. Dispose of used oil safely.
14.1.4 System Maintenance
0 When depressurizing a system do not vent
refrigerant directlyto atmosphere, always use Jaguar
approved recovery equipment.
0 Always decant compressor oil from a sealed con- tainer and do not leave oil exposed to the atmosphere
for any reason other than to fill or empty
a system.
PAG oil is very hygroscopic and will rapidly become
contaminated by atmospheric moisture.
0 Plug pipes and units immediately after disconnection
and only unplug immediately priorto connection. Do
not leave the system open to atmosphere.
0 It is not necessary to renew the receiver drier when- ever the system has been 'opened' as previously ad-
vised - see note this page. However,if a unit or part
of the system is left open for more than five minutes,
it may be advisable to renew the receiver drier. This
guidance is based on
U.K average humidity levels;
therefore, locations with lower humidity will be less
critical to moisturecontamination of the unit.
It must
be stressed that there is not
a 'safe' period for workto
be carried out in: ALWAYS plug pipes and units im-
mediately after disconnection and only remove plugs
immediately prior to connection.
J82-387
Fin. 1
U: The receiver / drier MUST be renewed if the compressor has failed or if it is suspected that debris may be in
the system.
0 If replacement parts are supplied without transit plugs and seals DO NOT use the parts. Return them to your
supplier.
0 Diagnostic equipment for pressure, mass and volume should be calibrated regularly and certified by a third
party organization.
0 Use extreme care when handling and securing aluminium fittings, always use a backing spanner and take
special care when handling the evaporator.
0 Use only the correct or recommended tools for the job and apply the manufacturer's torque specifications.
Issue 1 August 1994 2 X300 VSM