2010 JAGUAR XFR Control module

18 Pinion 19 Steering gear rack bar 20 Valve sleeve The valve unit is an integral part of the steering gear. The principle function of the valve unit is to provide power assistance
(i.e. when parking) to optimize the effort required to turn the steering wheel.

The pinion housing of the valve is an integral part of the main steering gear casting. The pinion housing has four machined
ports which provide connections for pressure feed from the power steering pump, return fluid to the reservoir and pressure
feeds to each side of the cylinder piston.

The valve unit comprises an outer sleeve, an input shaft, a torsion bar and a pinion shaft. The valve unit is co-axial with the
pinion shaft which is connected to the steering column via the input shaft. The valve unit components are located in the
steering gear pinion housing which is sealed with a cap.

The outer sleeve is located in the main bore of the pinion housing. Three annular grooves are machined on its outer diameter.
PTFE (polytetrafluoroethylene) rings are located between the grooves and seal against the bore of the pinion housing. Holes
are drilled radially in each annular groove through the wall of the sleeve. The bore of the outer sleeve is machined to accept
the input shaft. Six equally spaced slots are machined in the bore of the sleeve. The ends of the slots are closed and do not
continue to the end of the outer sleeve. The radial holes in the outer sleeve are drilled into each slot.

The input shaft has two machined flats at its outer end which allow for the attachment of the steering column intermediate
shaft yoke. The flats ensure that the intermediate shaft is fitted in the correct position. The inner end of the input shaft forms
a dog-tooth which mates with a slot in the pinion shaft. The fit of the dog-tooth in the slot allows a small amount of relative
rotation between the input shaft and the pinion shaft before the dog-tooth contacts the wall of the slot. This ensures that, if
the power assistance fails, the steering can be operated manually without over stressing the torsion bar. The central portion of
the input shaft has equally spaced longitudinal slots machined in its circumference. The slots are arranged alternately around
the input shaft.

The torsion bar is fitted inside the input shaft and is an interference fit in the pinion shaft. The torsion bar is connected to the
input shaft by a drive pin. The torsion bar is machined to a smaller diameter in its central section. The smaller diameter allows
the torsion bar to twist in response to torque applied from the steering wheel in relation to the grip of the tyres on the road
surface.

The pinion shaft has machined teeth on its central diameter which mate with teeth on the steering gear rack. A slot, machined
in the upper end of the pinion shaft mates with the dog-tooth on the input shaft. The pinion shaft locates in the pinion
housing and rotates on ball and roller bearings.

Servotronic Valve

The Servotronic transducer valve is located in a port in the side of the steering gear valve housing. The valve is sealed in the
housing with an O-ring seal and is secured with two long screws into threaded holes in the housing. The Servotronic valve is a
transducer controlled valve which responds to control signals supplied from Servotronic software in the instrument cluster.

The Servotronic valve determines the hydraulic reaction at the steering gear rotary valve and controls the input torque required
to turn the steering wheel. The Servotronic system allows the steering to be turned with the optimum effort when the vehicle
is stationary or manoeuvred at slow speed. The hydraulic reaction changes proportional to the vehicle speed, with the required
steering effort increasing as the vehicle moves faster. At high speeds, the Servotronic system provides the driver with a good
feedback through the steering providing precise steering and improved stability.

The instrument cluster receives road speed signals from the ABS module and calculates the correct controlling signal for the Servotronic valve. The Servotronic software within the instrument cluster has a diagnostic capability which allows a Jaguar
approved diagnostic system to check the tune of the steering and retrieve fault codes relating to the Servotronic valve. Two
fault codes are stored relating to the valve for positive connection short to ground or battery and negative connection short to
ground or battery.

The Servotronic software within the instrument cluster also contains a number of steering maps which are selected via the car
configuration file depending on the vehicle model and tire fitment.

If a failure of the Servotronic valve or software occurs, the system will suspend Servotronic assistance and only a default level
of assistance will be available. Fault codes relating to the fault are stored in the instrument cluster. No warning lamps are
illuminated and the driver may be aware of the steering being 'heavier' than usual.
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Steering Column - Steering Column - Overview
Description and Operation

OVERVIEW Published: 11-May-2011

The steering column comprises the upper column assembly, the lower column assembly and the steering wheel. The 3
components are positively connected together to pass driver rotary input from the steering wheel to a linear output of the
steering rack.

The upper column assembly contains electrical adjustment for steering wheel reach and rake, the electric steering lock
mechanism and the steering angle sensor. Steering adjustment memory positions are stored in the driver's seat module.

The electric steering column is a standard fitment on all models. The upper column assembly contains electrical adjustment for
steering wheel reach and rake, the electric column lock mechanism and the steering angle sensor. Steering adjustment memory
positions are stored in the driver's seat module. The column also features a 'tilt away' function which moves the steering
column away from the driver allowing easier exit and entry to the vehicle.

Column adjustment is provided by a single motor for both reach and rake adjustment. Operation of the column adjustment is
controlled by a four way joystick type switch located in the column lower shroud. Column adjustment is an integral part of the
driver position memory system.
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8 Reach adjustment solenoid and potentiometer 9 Column adjustment motor 10 Instrument cluster 11 Steering column adjust switch 12 Driver's seat module (position memory)


STEERING COLUMN ADJUSTMENT System Operation

Power for the column adjustment motor is supplied via a megafuse in the BJB to the CJB. A fused supply from the CJB is passed to the instrument cluster which controls the power application to the motor.

The column adjust switch is hardwired to the instrument cluster. Up/down and in/out selections on the switch are each passed
through a resistor of differing values to the instrument cluster. The cluster monitors the output value from the switch and
operates the motor in the required direction and simultaneously energizes the required solenoid for rake or reach adjustment.
When the applicable solenoid is energized, a clutch is engaged and locates on a lead screw. The motor rotates the lead screw
and the rotational drive of the screw is transferred into linear movement of the applicable clutch to move either the rake or
reach adjustment. For reach adjustment, the lead screw drives the outer housing in or out as required. For rake adjustment the
lead screw drives a rake lever which moves the column up or down as required.

The position of the column is monitored by potentiometers which are connected to the instrument cluster. The cluster monitors
the output signal from the potentiometers to precisely control the positioning of the column in each plane.

The instrument cluster controls the memory positioning of the column via a medium speed CAN bus connection to the driver's seat module. The driver's seat module receives information regarding the particular remote handset used to enter the vehicle
and outputs positional information relative to that stored for the handset. This information is passed to the instrument cluster
via the medium speed CAN bus which moves the column to the memorized positions.
The column logic in the instrument cluster also incorporates an entry/exit mode. When the vehicle is unlocked or the ignition is
switched off, the instrument cluster lifts the column upwards to its maximum rake position to allow the driver more room below
the steering wheel and improve access/egress of the vehicle. When the ignition is next switched on the column will adjust to
its previous position.
The electric steering column lock is controlled by the CJB.

16 Ball (12 off) 17 Distance keeper 18 Crash tube The column comprises a cast magnesium mounting bracket which provides the attachment to the cross-beam. Attached to the
mounting bracket is a rake lever which is attached to the mounting bracket at the lower end with two pivot bearings. The
bearings allow the rake lever to rotate upwards or downward to adjust the column rake.

The rake lever also provides for the attachment of the rake housing which can slide within the lever to provide the reach
adjustment. Within the rake housing is the axial housing which is supported on each side with 6 ball bearings which allow the
rake housing to move forward or backwards. The bearings on each side are arranged in groups of 3 bearings and are separated
by a distance keeper which allows the housing to supported on bearings along its length. Within the axial housing is a tube
which is supported at the upper end of the column on the upper bearing. The tube has a central splined hole which provides for
the fitment of the splined shaft. The splined shaft can slide within the tube on the splines when the column reach is adjusted
or the column collapses in a crash condition. The splined shaft also passes rotary motion from the steering wheel through the
length of the column to the outer clamping yoke which is supported on the lower bearing.

The electric steering column lock is attached to the top of the rake lever. A lock bolt within the steering column lock engages in
one of 8 slots in the locking sleeve located at the lower end of the column preventing rotation of the steering wheel. The
locking sleeve is retained by a tolerance ring which in turn is located on the outer diameter of the tube yoke. The tolerance
ring allows a specified amount of torque to be applied to the splined shaft before it slips, preventing damage to the column
lock due to excessive force being applied to the steering wheel when the lock is engaged. The tolerance ring is designed to
slip on the splined shaft when the applied torque exceeds the fitted slip load of 200 Nm minimum. Repeated rotation of the
lock collar will reduce its slipping torque to 100 Nm minimum. The lock is controlled by the CJB.
A steering angle sensor is located at the upper end of the steering column and is attached to the crash adaptor. The sensor
measures steering rotation via a toothed wheel located on the splined tube at the upper end of the column. The sensor
receives a power supply from the CJB and supplies 2 signals (A and B) relating to the steering rotation to the ABS (anti-lock brake system) module. The module transmits this data on the high speed CAN bus for use by other vehicle systems. Refer to: Anti-Lock Control - Stability Assist (206-09 Anti-Lock Control - Stability Assist, Description and Operation).
The steering column is adjustable electrically, for reach and rake. The adjustment mechanism comprises an electric adjustment
motor, a lead screw, a rake solenoid, a reach solenoid, a reach clutch and a rake clutch. The column adjustment is controlled
manually using a joystick switch located on the LH (left-hand) side of the column lower cowl. The joystick can be moved
forward and backward to adjust the column reach in and out and moved up and down to adjust the rake. The switch selection
energizes the adjustment motor in the applicable direction and also engages the applicable solenoid and clutch.

When the joystick switch is rotated to the 'auto' position, the steering column will adjust to the uppermost rake position when
the ignition is switched off. It will re-adjust to the position corresponding to the memory position for the remote handset when
the ignition is switched on.

The memory function of the electric column is linked to and controlled by the driver's seat module. The module provides for the
storage of three separate memory positions which are stored against 3 individual remote handsets.
Refer to: Seats (501-10 Seating, Description and Operation).
The steering wheel locates on a splined shaft in the upper column assembly and is secured with a bolt. The steering wheel
houses the driver's airbag and switches for the audio system, gear change and speed control. A clockspring is used to connect
the steering wheel electrical components to the vehicle harness.

Two plastic shrouds are fitted to the upper column assembly. The lower shroud is fitted with an energy absorbing foam pad to
minimize leg injury in the event of an accident.
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Published: 11-May-2011
Steering Column Switches - Steering Column Switches - System Operation
and Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired; N = Medium speed CAN bus; P = Fibre Optic MOST ring



Item Description 1 Battery 2 BJB (battery junction box) 3 CJB (central junction box) 4 Heated steering wheel slip rings 5 Heated steering wheel control module 6 Steering wheel heater element

8 Steering column LH (left-hand) multifunction switch 9 Steering column RH (right-hand) multifunction switch 10 Instrument cluster 11 Speed control switches 12 Audio/telephone switches 13 Clockspring 14 Information and entertainment module 15 Media Oriented System Transport (MOST) ring connection to other vehicle systems 16 Medium speed CAN (controller area network) bus to other vehicle systems


LEFT HAND MULTIFUNCTION SWITCH

Turn Signal Indicators System Operation

The instrument cluster outputs a reference voltage to the turn signal indicator switch. When the switch is in the central off
position, the voltage flows through 3 resistors which are connected in series and back to the instrument cluster which monitors
the signal and determines the turn signal indicators are off. This information is broadcast on the medium speed CAN bus to the CJB.
When the switch is operated in the LH turn signal indicator position, the reference voltage from the instrument cluster is routed via 1 of the resistors. The returned signal voltage is detected by the instrument cluster which outputs a message on
the medium speed CAN bus to the CJB. The CJB activates the applicable turn signal indicators until it receives an off message from the instrument cluster.

When the switch is operated in the RH turn signal indicator position, the reference voltage from the instrument cluster is routed via 2 of the resistors. The returned signal voltage is detected by the instrument cluster which outputs a message on
the medium speed CAN bus to the CJB. The CJB activates the applicable turn signal indicators until it receives an off message from the instrument cluster.
Lighting Control Switch

The instrument cluster outputs 2 reference voltages to the rotary lighting control switch; one feed being supplied to the light
selection function of the switch and the second feed being supplied to the autolamp exit delay function. The switch position is
determined by instrument cluster by the change in returned signal voltage which is routed through up to 4 resistors in series
depending on the selection made.

When the lighting control switch is in the off position, the reference voltage flows through 1 of the resistors. The returned
signal voltage is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that no lighting selection is made. The reference voltage to the autolamp exit delay switch is routed through 4 resistors which is
detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that autolamp or exit delay has not been selected.

When the lighting control switch is in the sidelamp position, the reference voltage flows through 2 of the resistors. The
returned signal voltage is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the sidelamps. The reference voltage to the autolamp exit delay switch is routed through 4 resistors which is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that autolamp or exit delay has not been selected.

When the lighting control switch is in the headlamp position, the reference voltage flows through 3 of the resistors. The
returned signal voltage is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the headlamps. The reference voltage to the autolamp exit delay switch is routed through 4 resistors which is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that autolamp or exit delay has not been selected.

When the lighting control switch is in the autolamp position, the reference voltage flows through 4 of the resistors. The
returned signal voltage is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the autolamp function. The reference voltage to the autolamp exit delay switch is routed through 4 resistors which is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that autolamp has been selected.
Autolamp Exit Delay

When the lighting control switch is in any of the autolamp exit delay position, the lighting control switch reference voltage
flows through 4 of the resistors. The returned signal voltage is detected by the instrument cluster which outputs a message on
the medium speed CAN bus to the CJB that autolamps has been selected.
Depending on the selected position, the reference voltage to the autolamp exit delay switch is routed through 3, 2 or 1
resistors which is detected by the instrument cluster. The cluster outputs a message on the medium speed CAN bus to the CJB that autolamp exit delay period has been selected at 30, 60 or 120 seconds respectively.
Trip Function Button

The instrument cluster outputs a reference voltage to the trip function button. When the function button is pressed a ground

path is completed and a signal voltage is returned to the instrument cluster via a resistor. The returned reference voltage is
detected by the instrument cluster and performs the requested trip function.

RIGHT HAND MULTIFUNCTION SWITCH
The instrument cluster outputs 4 separate reference voltages to the following switch functions:
Wash/wipe switch
Intermittent wipe switch
Master wiper switch
Flick wipe switch.
Wash/Wipe Switch

The reference voltage is supplied to one of two resistors connected in parallel. When the switch is not being operated the
current flows through one resistor and the returned signal voltage is monitored by the instrument cluster. When the wash/wipe
switch is operated, a connection is made and the current flows through the second resistor. The change in signal voltage is
detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the wash/wipe function.
Intermittent Delay/Auto Wipe Switch

The reference voltage is supplied to the switch and can pass through up to 7 resistors, connected in series, for intermittent
delay selections and the auto wipe function.

When the rotary switch is in the auto position the reference voltage flows through 1 resistor. The returned signal voltage is
detected by the instrument cluster which determines auto wipe is selected. The instrument cluster outputs a message on the
medium speed CAN bus to the CJB to activate the auto wipe function.
With the rotary switch in one of the intermittent positions, the reference voltage is routed through up to 7 of the resistors
depending on the delay period selected. The returned signal voltage is detected by the instrument cluster which determines
selected delay period. The instrument cluster outputs a message on the medium speed CAN bus to the CJB to activate the selected intermittent wipe function.


NOTE: The delay period for the intermittent selections can vary according to vehicle speed.

Master Wiper Switch

The reference voltage supplied from the instrument cluster to the master wiper switch. The voltage can pass through up to 4
resistors connected in series.

When the switch is in the off position, the reference voltage passes through 4 resistors and the returned voltage is monitored
by the instrument cluster. The instrument cluster outputs a message on the medium speed CAN bus to the CJB that no wiper selections have been requested.

With the switch in the intermittent, slow wipe or fast wipe position, the reference voltage passes through 3, 2 or 1 resistors
respectively. The returned signal voltage is detected by the instrument cluster which determines selected delay period. The
instrument cluster outputs a message on the medium speed CAN bus to the CJB to activate the selected wipe function. Flick Wipe Switch

The reference voltage is supplied to one of two resistors connected in parallel. When the switch is not being operated the
current flows through one resistor and the returned signal voltage is monitored by the instrument cluster. When the flick wipe
switch is operated, a connection is made and the current flows through the second resistor. The change in signal voltage is
detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the flick wipe function.

STEERING COLUMN ADJUSTMENT SWITCH

The instrument cluster supplies 2 reference voltages to the column adjustment switch.

The first reference voltage is supplied to the joystick switch. When the switch is moved to one of its 4 positions, the switch
contact is completed and the reference voltage is passed through one of 4 different resistors with different values. The
returned signal voltage is measured by the instrument cluster which determines the selected column adjust request. The
instrument cluster outputs a supply to the steering column adjustment motor and energizes the applicable clutch solenoid to
move the column to the desired position.

The second reference voltage is supplied to the auto/manual selection of the switch. When the switch is in the auto position,
the reference voltage passes directly through the switch contacts and is measured by the instrument cluster. The instrument
cluster outputs a message on the medium speed CAN bus to the driver seat module which responds with the recorded memory position setting. The instrument cluster then activates the column adjustment motor and clutch solenoids to move the column
to the memorized position. When the switch is in the manual position the reference circuit is broken. The instrument cluster
detects the broken circuit and allows manual operation of the column adjustment switch to move the column.

HEATED STEERING WHEEL

The heated steering wheel receives a battery power supply via the CJB. The heated steering wheel is controlled by the driver using a selection on the TSD. When the driver selects the heated steering wheel to be active, the request is passed from the
TSD on the MOST ring to the information and entertainment module. The information and entertainment module converts the

battery power supply to be passed via the slip ring assembly in the steering wheel to the heated steering wheel control
module. The steering wheel module supplies power to the steering wheel heater element and also monitors the temperature
via a NTC (negative temperature coefficient) temperature sensor incorporated into the heater element. The control module
varies the power supply to the element to maintain the steering wheel rim at the optimum temperature.

Component Description STEERING COLUMN MULTIFUNCTION SWITCHES
The steering column multifunction switches are situated on the steering column and consists of the wiper switch, the turn
signal indicator/lighting switch and the trip computer switch.

The steering column adjustment switch is located in the steering column lower shroud on the LH side. The switch is a 4 position 'joystick' which controls reach and rake adjustment.

Steering wheel mounted switches on the LH side of the driver's airbag, control the audio and telephone functions. Switches on the RH side of the driver's airbag, control the speed control functions. For additional information, refer to:
Audio System (415-01A Information and Entertainment System, Description and Operation), Speed Control (310-03A, Description and Operation),
Speed Control (310-03B, Description and Operation),
Speed Control (310-03C, Description and Operation).

Two transmission paddle switches are located at the rear of the steering wheel.
Refer to: External Controls (307-05, Description and Operation).
LH Multifunction Switch



Item Description 1 High beam 2 Lighting control rotary switch 3 RH turn signal indicator 4 Headlamp flash 5 LH turn signal indicator 6 Trip computer function button The LH multifunction switch controls the following windshield wiper functions: