JAGUARS-TYPEChassis
58
Power Assisted Steering
Introduction
The Jaguar S-TYPE has a variable assist rack and
pinion steering gear and variable rack ratio. The
variable steering rack ratio reduces the number of
turns from lock to lock (2.8) to enhance parking
manoeuvrability whilst maintaining the on-centre
steering precision required at high speed. Full
power assistance is provided for parking. Steering
assistance decreases smoothly at a calibrated rate
to raise driver steering efforts as vehicle speed
increases.
Servicing
There are no carry over parts from XK or XJ Series
vehicles.
The rack is mounted to the rear of cross member
Number 2. The PAS pump is belt driven. A PAS
cooler matrix is located within the radiator
package.
Low PAS pump speeds problems are prevented by
increasing engine speed. A power steering
pressure (PSP) switch senses the demand on the
pump at low engine speeds and increases the
speed to a pre-set minimum.
Hose connections to the pump and the steering
gear are quickfit connectors. The quick connect
tube must be pushed into the existing tube nut
port, along the centreline. The assembly is
complete when the tube end bottoms out in the
port with an audible click/snap. Correct assembly
should be verified by pulling the quickfit tube end.
Servicing of the PAS line involves removal of the
quickfit nut. Replacement PAS lines are supplied
complete with quickfit nut and sealing washer. If
the joint is disturbed it is compulsory to replace
the PTFE sealing ring otherwise leaks are
inevitable. Replacement sealing washers may be
installed with the use of Service tool
D90P-3517-A.
Care must be taken when removing the quickfit
nut from the V6 engine pump as the pulley is
PHENOLIC and is susceptible to damage. The V8
pump installation provides a short jumper tube
from the pump to improve accessibility to the
high-pressure hose connection. The PAS pulley
D.211.247
PA S R AC K
D.211.258
POWER STEERING PRESSURE SWITCH
JAGUARS-TYPEChassis
59
D.211.248
FRONT STEERING ARM requires a Service tool to assist removal. Low-
pressure hose connections are made using
Constant Tension (CT) clamps. Pinion hydraulic
connections are orientated with the bottom
connector low pressure with the longer nut, as
current vehicles.
The PAS fluid is for PAS only; it is not to be used
for transmissions. After manual filling, the system
must be bled using a vacuum pump to remove all
the air from the system to prevent system noises.
Fluid level is checked through a sight window on
the reservoir.
Components replaceable are complete pump,
steering rack, reservoir or hose assembly.
A non-serviceable 10-micron filter is located
within the reservoir to maintain fluid cleanliness
throughout the life of the vehicle. It is essential as
with all Jaguars that the system does not become
contaminated. Cap all ports on disassembly to
prevent contamination ingress. As with current
vehicles, the fluid and reservoir must be renewed
if any major component is replaced i.e. Rack,
pump or cooler.
The road wheels should be set straight ahead and
the steering wheel locked (using service tool
F7LC-3F732-BF) when removal and assembly of
the steering gear or intermediate shaft is required.
This is necessary to prevent damage to the air bag
clock spring within the steering upper column
assembly. The intermediate shaft can only be
assembled to its mating components in one
location. Steering wheel alignment can only be
achieved by adjustment at the tie-rods. A
dimensional check of the steering rack position
may be necessary to verify rack centre.
Steering Column
The steering column assembly is completely new
and uses no parts from previous Jaguar
assemblies:
¥ Construction of the upper column assembly is
based on the use of aluminium extrusions and
castings.
¥ A two shaft lower column assembly is used.
¥ The electronically controlled steering lock, the
steering column lock module (SCLM), is a
physically separate component from the
ignition switch which is fascia mounted.
¥ The dynamic stability control (DSC) steering
wheel position sensor is fitted to the upper
column assembly.
Steering Wheel
The steering wheel consists of a magnesium
armature with a central steel insert. The steering
column and wheel insert are splined with a flat so
that the wheel can only be fitted in one position.
Any misalignment of the steering wheel is
corrected by adjusting the tie rods. The splined
fitting also has a locking taper which requires the
use of a 2 legged puller to remove the wheel.
The steering wheel incorporates the the airbag
module, horn mechanism and the optional cruise
control and audio/phone switches.
JAGUARS-TYPEChassis
61
D.211.253
LOWER STEERING COLUMN
Lower Steering Column Assembly
The adjustable column assembly is connected to
the steering rack via a lower assembly consisting
of two shafts linked by a universal joint. The lower
shaft incorporates a sliding section which is
secured by a pinch bolt on installation. To stabilise
the shaft to shaft joint, the upper of the two shafts
is supported by a bearing assembly where it passes
through the bulkhead.
Gaiter
Bearing and Seal
Slider
¥ Steering column lock module (SCLM) with
splined locking collar on the column.
¥ The retractor box, mounted on the underside
of the lower extrusion, houses the column
wiring harness and connectors with sufficient
cable to allow for column telescopic
movement.
JAGUARS-TYPEChassis
62
J.211.257
STEERING COLUMN LOCK MODULE
Steering Column Lock (where fitted)
Lock Operation
The steering column lock module (SCLM) and
ignition key switch are separate assemblies and
activation of the lock is remotely controlled by the
instrument pack, GECM and RECM. The column is
unlocked on insertion of the ignition key and is
locked when the key is withdrawn.
The SCLM is mounted on top of the lower casting,
on the upper column assembly, by two shear
bolts. A locking bolt projects down from the SCLM
through a hole in the lower casting to engage into
a splined collar on the steering column. The SCLM
is an integrated non-serviceable assembly, housinga motor and worm drive for the locking bolt and
also an electronic printed circuit board. When
activated, the locking bolt is driven positively in
both the lock (down) and unlock (up) directions
and has a spring to help locate it into the trough
of the splined collar. When disengaging, the
locking bolt is driven upwards until it operates a
microswitch (within the SCLM) which causes the
motor to stop and also signals via the SCP bus that
the steering lock is off. To engage the lock, the
motor is energised for 350ms to lower the bolt.
System Control
The lock motor is powered by a switched 12V line
from the RECM and switched ground line from the
GECM, with both supplies being applied only
during lock operation. Initiation of motor drive
and direction and power supply switching is
controlled by the instrument pack via the SCP bus
when ignition key insertion or withdrawal is
detected. Identification is checked between the
SCLM and the other modules and the system will
not operate if, for example, a module has been
replaced and not re-programmed. System
diagnostics include defective modules and
incorrect module identification and also certain
SCLM faults, ie unconfimed lock or unlock
conditions and failed microswitch.
Steering Column Shrouds
The upper part of the column assembly is
enclosed by two plastic shrouds, upper and lower.
The steering column adjust switch, controlling tilt
and reach for the electrically powered steering
column assembly, is mounted on the side of the
lower shroud.
SCLM
JAGUARS-TYPEClimate Control
67 Pipework
The suction hose and liquid line are a one-piece
assembly. A single screw connects them to the air
conditioning unit manifold at the bulkhead. A
further screw fixing and push-in clip secures them
at the side of the engine bay. The liquid line fixed
to the cooling module then joins with a block
fitting and the suction hose connects with a quick
connect fitting and routes across the underneath
of the cooling module to the compressor. The
compressor suction and discharge hoses are also a
one piece assembly.
A pressure transducer is fitted to the discharge
hose as it connects to the rear of the condenser.
The high side charge port is situated on the
manifold connecting to the receiver drier whilst
the low side is adjacent to the compressor behind
the LH front wheel.
The compressor is a 9Occ scroll, which is variable
from 100% to 30%. Compressor is standard
specification to all vehicles although package
makes them unique to V6 and V8.
Air Distribution
Air distribution is as follows:
¥ Defrost duct integral with the fascia.
¥ Face vents, plenum, manifold, centre face
duct, side face duct, side window demist duct
are all sub-assembled into the fascia.
¥ Driver and front seat passenger foot ducts are
installed in the fascia after it has been fitted
to the vehicle.
¥ Rear foot ducts are fitted to the underframe.
¥ Rear face duct fitted to transmission tunnel.
¥ Rear face vent fitted to console.
¥ Extractor boxes fitted in rear quarter panels.
All flaps are electric servo controlled and
comprise:
¥ Fresh/recirculation - heater/evaporator unit.
¥ Cold air bypass - heater/evaporator unit.
¥ Foot flap - mounted on plenum.
¥ Defrost flap - mounted on plenum.
¥ Face flap - mounted on plenum.
Sensors, for operation of the system, are:
¥ Ambient temperature sensor - located behind
the lower front grille.
¥ Solar sensor - fitted to the top centre of the
fascia at the defrost grille
¥ In-car sensor - aspirated from the plenum
venturi sensor mounted inboard of the
steering column.¥ Two heater air outlet sensors
¥ One evaporator air outlet sensor
Servicing
Routine servicing consists of particle filter
replacement.
Replaceable items on the climate control system
are:
¥ Servo complete with linkages
¥ Sensors
¥ Evaporator and seals
¥ Heater core and seals
¥ Blower motor
¥ Impeller/blower motor wheel
¥ Hoses
¥ Registers/vents
¥ Ducts, except the defrost
¥ Defrost and side window demist grilles
¥ Control unit
¥ Compressor
¥ Water pump
¥ Water valve
¥ Receiver/drier
¥ Condenser
There are no panel diagnostics but PDU facility is
available with extensive capability, similar to
current XJ and XK Series.
System refrigerant is R134a. Vehicle charge weight
is 800 gms and charging is through the high side
charge port only.
Oil type is WSH-MIC231-B and refill quantity is
180 cc -220 cc.
Special tools are hose clamp pliers and air-
conditioning hoses spring lock de-coupler.
General information
Ensure that the grille at the base of the windshield
is kept clear of leaves, snow or other obstructions.
A solar sensor is mounted on top of the fascia, in
the centre of the defrost grille, and this should not
be covered.
The air conditioning system should be run briefly
at least once each week with a cold setting to
prevent the seals from drying out with subsequent
refrigerant leaks.
When the engine and vehicle interior are cold the
fan speed may be low until the engine has warmed
up, this avoids excessively cold air being blown
into the cabin.
JAGUARS-TYPEElectrical/Electronic
70
BATTERY AND FUSE BOX POWER DISTRIBUTION
1. Front power distribution box (fusebox)
2. Primary junction box (fusebox)
3. Power stud
4. Battery Positive cable
5. Rear power distribution box (fusebox)
6. Battery Negative cable
7. Battery8. Clean power fuse (Megafuse)
9. Clean power feed
10. Secondary junction box.
11. Starter motor
12. Alternator/starter positive cable
13. Alternator
Power Distribution Cables
Heavy duty power distribution cables connect the
battery to the body and to the engine starter and
the vehicle fuse boxes. The distribution cable from
the clean power fuse to the front fusebox is
routed on the LH side of the vehicle and along
part of the main body wiring harness.
Harnesses
The vehicle harnesses plug directly into
components or component flying leads using
locking connectors. The main harness layout is
shown in the illustration on the following page.
12
10
4
1113
3
9
8
65
7
12
JAGUARS-TYPEElectrical/Electronic
73 STANDARD CORPORATE PROTOCOL (SCP) NETWORK
Powertrain
Control Module
Vehicle Emergency
Control Module
Throttle Actuator
Control Module
General Electronic
Control Module
Rear Electronic
Control Module
Navigation
Control Module
Adaptive Damping
Control Module
Voice Activation
Control Module
Air Conditioning
Control Module
Data Link
Connector
Instrument
Pack
Audio Unit
Steering Column
Lock Module
Dynamic Stability
Control Module
Secondary
Junction BoxDriver Seat
Control Module
Driver Door
Control Module
ABS/TC
Control Module
JAGUARS-TYPEElectrical/Electronic
74The SCP communication network will remain
operational even with severing of one of the bus
wires. Communications will also continue if one
of the bus wires is shorted to ground or battery
positive voltage (B+), or if some , but not all,
termination resistors are lost.
Unlike the SCP communication network, the
ISO 9141 communication network will not
function if the wire is shorted to ground or battery
positive voltage (B+). Also, if one of the modules
on the ISO 9141 network loses power or shorts
internally, communication to that module will fail.
Control Modules
The vehicle control module functions are
described briefly below (for further information
refer to the relevant sections throughout the
Guide).
Anti Lock Brake/Traction Control and
Dynamic Stability Control, Control Modules
The anti-lock brake control module is connected
to the SCP communication network. The module
comes in two forms. The first type is the standard
equipped anti-lock brake system (ABS) with
traction control (TC). It controls the brake
pressure to the four wheels to keep the vehicle
under control while braking.
The second type of ABS is optional and is called
dynamic stability control (DSC). This control
module adds yaw sensors to the package to help
in sensing a loss of vehicle control.
Audio Control Unit
The audio control unit is connected to the SCP
communication network and also to the audio
control protocol (ACP) communication network.
The audio control unit communicates with the
compact disc and the cellular phone transceiver.
Driver Door Control Module (DDCM)
DDCM is connected to the SCP communication
network. The module controls many functions
including power windows, driver mirror, power
locks, and keyless remote entry.Driver Seat Control Module (DSCM)
The DSCM is connected to the SCP
communication network. The DSCM is located
under the driver seat and controls the seat
positions. The module also communicates with the
DDCM to control the driver seat memory
functions.
Control Module Locations
Key to illustration on following page:
1.Anti-lock brake system/Traction control
system or Dynamic stability control
(ABS/TCCM or DSCCM)
(non-handed)
2.Throttle actuator control module (TACM)
(non-handed)
3.Powertrain control module (PCM) (handed)
4.Air conditioning control module (A/CCM)
(non-handed)
5.Restraint control module (RCM) (non-handed)
6.Sliding roof control module (SRCM)
(non-handed)
7.Passenger seat heater control module
(PSHCM) (non-handed)
8.Rear electronic control module (RECM)
(non-handed)
9.Vehicle information control module (VICM)
(Japan only)
10.Adaptive damping control module (ADCM)
(non-handed)
11.Parking aid control module (PACM)
(non-handed)
12.Navigation control module (NCM)
(non-handed)
13.Vehicle emergency control module (VECM)
(non-handed)
14.Voice-activated control module (VACM)
(non-handed)
15.Cellular telephone control module (CTCM)
(non-handed)
16.Driver seat heater control module (DSHCM)
(non-handed)
17.Driver seat control module (DSCM) (handed)
18.Driver door control module (DDCM)
(handed)
19.Instrument pack (handed)
20.General electronics control module (GECM)
(non-handed)
21.Steering column lock module (SCLM) (handed)