ignition JAGUAR XFR 2010 1.G Repair Manual

7 Brake fluid level switch 8 LH rear wheel speed sensor 9 RH rear wheel speed sensor 10 RJB (rear junction box) 11 High mounted stop lamp 12 LH stop lamp 13 RH stop lamp 14 Diagnostic socket 15 TCM (transmission control module) 16 Electronic parking brake module 17 ECM (engine control module) 18 Instrument cluster 19 ABS (anti-lock brake system) module 20 JaguarDrive selector module 21 Adaptive damping control module 22 Adaptive speed control module 23 Yaw rate and lateral acceleration sensor 24 Roof opening panel motor/module 25 Brake booster vacuum sensor (3.0L vehicles only) 26 Steering angle sensor


Anti-Lock Brake System System Operation

ABS controls the speed of all road wheels to ensure optimum wheel slip when braking at the adhesion limit. The wheels are prevented from locking to retain effective steering control of the vehicle.

The brake pressures are modulated separately for each wheel. Rear brake pressures are controlled to maintain rear stability on
split friction surfaces.

Dynamic Stability Control

DSC (dynamic stability control) uses brakes and powertrain torque control to assist in maintaining the yaw stability of the
vehicle. While the ignition is energized the DSC function is permanently enabled, unless selected off using the DSC switch.

DSC enhances driving safety in abrupt maneuvers and in under-steer or over-steer situations that may occur in a bend. The
ABS module monitors the yaw rate and lateral acceleration of the vehicle, steering input and individual wheel speeds, then selectively applies individual brakes and signals for powertrain torque adjustments to reduce under-steer or over-steer
conditions.
In general:

In an under-steer situation the inner wheels are braked to counteract the yaw movement towards the outer edge of the
bend.
In an over-steer situation the outer wheels are braked to prevent the rear end of the vehicle from pushing towards the
outer edge of the bend.

The ABS module monitors the tracking stability of the vehicle using inputs from the wheel speed sensors, the steering angle sensor, and the yaw rate and lateral acceleration sensor. The tracking stability is compared with stored target data. Whenever
the tracking stability deviates from the target data, the ABS module intervenes by applying the appropriate control strategy. The following interactions occur in an intervention situation:

High speed CAN signal to the ECM, to reduce engine torque. Application of braking to the appropriate corner of the vehicle.
Trac DSC

TracDSC is an alternative setting of DSC with reduced system interventions. With TracDSC engaged, traction may be somewhat
increased, although stability may be reduced compared to normal DSC. TracDSC is intended for use only on dry tarmac, by
suitably experienced drivers and should not be selected for other surfaces or by drivers with insufficient skill and training to
operate the vehicle safely with the TracDSC function engaged.

The less restrictive TracDSC setting may be preferred, for example, by expert drivers engaged in high performance driving on
dry Tarmac surfaces such as tracks and circuits.
Switching between DSC and Trac DSC:

a decrease in engine torque. At the same time the ABS module will control the HCU to apply brake pressure to the relevant wheels to correct the understeer.

Electronic Brake Prefill (Vehicles With ACC Only)

Electronic brake prefill (Bosch ESP®plus8.1), senses any rapid throttle lift off, activating a small brake hydraulic pressure
build-up of approximately 3 to 5 bar (43.5 to 72.5 lbf/in²) in anticipation of the brakes being applied.

This application produces a quicker brake pedal response and consequently slightly shorter stopping distances. The system
supports vehicles with ACC (adaptive cruise control).

When the ABS module detects rapid throttle lift off (from the signals received from the ECM over the high speed CAN bus), it controls the HCU to apply a low brake pressure to assist in a quicker brake application.
Brake Vacuum Assist (3.0L Vehicles Only)

Operation of Brake Vacuum Assist generally occurs at the beginning of an ignition cycle when brake booster vacuum levels are
low; refer to Brake Booster Vacuum sensor, below.

Brake vacuum assist operation will be recognized by the driver experiencing a vibrating brake pedal and slight modulator noise.
This will be similar to that experienced when ABS system is operating.
As the engine warms up, Brake Vacuum Assist operation will become less frequent. However, it can be become more active
when vacuum levels are low due to driving at high-altitudes, or during frequent heavy-braking.

Noise levels during Brake Vacuum Assist may vary with initial system activity being the loudest observed. In some
circumstances initial activity may be interpreted as a 'thump' noise, particularly if there is no immediate and significant Brake
Vacuum Assist functionality.
In this circumstance system behavior is normal and should not be a cause for fault investigation.



Dynamic Stability Control Switch Component Description



Item Description 1 DSC switch The DSC switch is mounted in the floor console adjacent to the JaguarDrive selector.

DSC becomes active whenever the engine is running. A momentary press of the switch allows the driver to toggle between the
standard DSC settings and the optimized 'Trac DSC' settings. The message 'Trac DSC' or 'DSC on' will temporarily be displayed
in the instrument cluster message center. The amber DSC warning indicator in the instrument cluster remains illuminated while
'Trac DSC' is selected.
The DSC can be switched off by pressing and holding the switch for more than 10 seconds.

In each case the message 'DSC OFF' will be displayed in the instrument cluster message center to confirm DSC has been
switched off. The amber DSC warning indicator in the instrument cluster will remain illuminated. The system can be switched
back on again by simply pressing and releasing the switch. The message 'DSC ON' will then temporarily appear in the
instrument cluster message center to confirm the system is on.


NOTE: Switch requests may be delayed if the switch is pressed while a DSC operation is taking place. The switch request
will be displayed in the instrument cluster but the ABS module will not initiate any stability changes until it is safe to do so.
If a fault is detected with the DSC switch, the ABS module defaults to the 'DSC ON' setting and any switch requests are ignored.


WARNING: It is recommended that when using snow chains, Trac DSC is switched off and JaguarDrive control winter mode
is selected.

Wheel Speed Sensors



Item Description 1 Front wheel speed sensor 2 Rear wheel speed sensor An active wheel speed sensor is installed in each wheel hub to provide the ABS module with a rotational speed signal from each road wheel. The head of each front wheel speed sensor is positioned close to a magnetic encoder ring incorporated into
the inboard seal of the wheel bearing. The head of each rear wheel speed sensor is positioned close to a magnetic encoder
ring incorporated into the rear wheel bearing assembly. Each encoder ring contains 46 north and south poles. A fly lead
connects each sensor to the vehicle harness.

The wheel speed sensors each have a signal and a return connection with the ABS module. When the ignition is ON the ABS module supplies a signal feed to the wheel speed sensors and monitors the return signals. Any rotation of the road wheels
induces current fluctuations in the return signals, which are converted into individual wheel speeds and overall vehicle speed
by the ABS module. The ABS module broadcasts the individual wheel speeds and the vehicle speed on the high speed CAN bus for use by other

beams change state. The LEDs and detectors are mounted in such a way that only one beam will change state, either to broken or restored, at any one time.

The center (straight ahead) position of the steering wheel has to be learned by the ABS module every time the ignition is switched ON. The steering angle sensor is unable to determine the center position so inputs from the yaw rate and lateral
acceleration sensor and wheel speed signals are also used by the ABS module to help it perform this process. If extreme weather conditions are present, for example ice causing extreme wheel spin or understeer/oversteer, the ABS module may not be able to determine the center position of the steering wheel. In this situation 'DSC NOT AVAILABLE' will be displayed in the
instrument cluster message center and the amber warning indicator will illuminate.
Refer to: Information and Message Center (413-08 Information and Message Center, Description and Operation).

'DSC NOT AVAILABLE' will also be displayed if the ABS module detects a steering angle sensor fault. The amber warning indicator will illuminate until the fault is rectified.

Yaw Rate and Lateral Acceleration Sensor



The yaw rate and lateral acceleration sensor is mounted on the rear parcel shelf. The sensor is secured by two screws and
connects to the vehicle wiring via a four pin multiplug.

When the ignition is ON, the sensor receives a power feed from the CJB. The ground path for the sensor is located behind the left hand rear seat back. The sensor measures the yaw rate and lateral acceleration of the vehicle, providing values to the ABS module via a dedicated, private high speed CAN bus connection. The ABS module broadcasts these values on the high speed CAN bus for use by other systems.
If a sensor fault is detected by the ABS module, 'DSC NOT AVAILABLE' will be displayed in the instrument cluster message center and the amber warning indicator will illuminate.
Refer to: Information and Message Center (413-08 Information and Message Center, Description and Operation).

Published: 09-Jul-2014
Anti-Lock Control - Stability Assist - Anti-Lock Control - Stability Assist
Diagnosis and Testing

Principle of Operation

For a detailed description of the Anti-Lock Control - Stability Assist system, refer to the relevant Description and Operation
sections in the workshop manual. REFER to: (206-09 Anti-Lock Control - Stability Assist)

Anti-Lock Control - Stability Assist (Description and Operation), Anti-Lock Control - Stability Assist (Description and Operation), Anti-Lock Control - Stability Assist (Description and Operation).
Inspection and Verification


CAUTION: Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not
guarantee confirmation of a fault, and may also cause additional faults in the vehicle being tested and/or the donor vehicle.
1. Verify the customer concern.
2. Confirm if the Anti-Lock Brake System (ABS) warning light was illuminated, or still is.

NOTE: An intermittent fault may allow the warning light to go off. This does not necessarily mean the fault is not
present. Some warnings will appear to clear when the ignition is cycled. This is often because the warning has flagged as a
result of one of the vehicle's on-board diagnostic routines having run to detect the fault. If the same routine is not run when
the ignition status is set to ON, the warning will not re-flag until the routine does run.
3. Visually inspect for obvious signs of damage and system integrity.

Visual Inspection
Mechanical Electrical
Brake fluid level
Vacuum system
Wheel speed sensor installation
Wheel speed sensor air gap
Magnetic pulse wheel(s) (damaged/contaminated)
Steering angle sensor
Yaw rate sensor and accelerometer cluster installation
Incorrect wheel or tire size
Warning light operation
Fuses
Wheel speed sensors
Connectors/Pins
Harnesses
Steering wheel rotation sensor
Yaw rate sensor and accelerometer cluster
Booster pressure sensor
Hydraulic Control Unit (HCU)
4. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to
the next step.
5. If the cause is not visually evident check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.

DTC Index

For a list of Diagnostic Trouble Codes (DTCs) that could be logged on this vehicle, please refer to Section 100-00.
REFER to: Diagnostic Trouble Code (DTC) Index - DTC: Anti-Lock Braking System (ABS) (100-00 General Information, Description and Operation).

Anti-Lock Control - Stability Assist - Rear Wheel Speed Sensor
Removal and Installation Published: 11-May-2011



NOTES: Removal

Removal steps in this procedure may contain installation details.


The ignition must be switched off.


Some variation in the illustrations may occur, but the essential information is always correct.


1. WARNING: Do not work on or under a vehicle supported only by a jack.
Always support the vehicle on safety stands.
Raise and support the vehicle.

2. Disconnect the wheel speed sensor electrical connector.

between moving components such as the steering wheel to steering column shroud.

Grunt (Squawk/Whoop)

Grunt is a 'honking' sound elicited when coming off one of the steering stops. Grunt is generally excited during parking
manoeuvres with a low to medium speed steering input.

Hiss (Swish)

Hiss or Valve Hiss is a high-frequency sound coming from the steering gear when the system is loaded. It is a rushing or
'swish' noise that doesn't change frequency with RPM. Hiss is the general noise generated by the flow of hydraulic fluid through
restrictions in the steering system. Restrictions include the rotary steering valve, power steering tubes, connectors, tuning
orifices, etc. Hiss can be air-borne and structure-borne, but the structure-borne path through the steering intermediate shaft is
usually dominant.

Moan (Groan)

Moan is the general structure-borne noise of the steering system. Moan is primarily transmitted to the driver via the body
structure through the pump mount, engine mounts, power steering lines and power steering brackets. On some vehicles, moan
is a loud humming noise, often present when the wheel is turned and the system is loaded. It may change frequency with
engine RPM and if the system is loaded or unloaded.

Steering Gear Knock (Steering Gear Slap)


CAUTION: DO NOT attempt to adjust the steering gear yoke. Failure to follow this instruction will invalidate the steering
gear warranty.

Steering gear knock is a rattle sound and steering wheel vibration caused by separation of the steering gear and pinion while
driving over bumps. It is a structure-borne noise transmitted through the intermediate shaft and column. Steering gear knock
can also be heard as a 'thump' or impact noise that occurs with the vehicle stationary when the steering wheel is released
from a loaded position and allowed to return to rest. Noise occurs with the engine on or off.

Rattles

Rattles are noises caused by knocking or hitting of components in the steering system. Steering rattles can occur in the engine
compartment, the suspension, or the passenger compartment. Rattles can be caused by loose components, movable and
flexible components, and improper clearances.

Squeaks/Scrapes

Squeaks/Scrapes are noises due to friction or component rubbing anywhere in the steering system. Squeaks/Scrapes have
appeared in steering linkages and joints, in column components and in column and steering wheel trim.

Weep

Weep is an air-borne noise, occasionally generated when turning the steering across lock at a constant rate. When present on
a vehicle the noise, once initiated can often be maintained across a large proportion of the available steering movement.

Whistle

Whistle is similar to hiss but is louder and of a higher frequency. It is also more of a pure tone noise than hiss. Whistle is
air-borne and is generated by a high flow rate of hydraulic fluid through a small restriction.

Zip

Zip noise is the air-borne noise generated by power steering pump cavitation when power steering fluid does not flow freely
through the suction hose from the reservoir to the pump. Zip primarily occurs during cold weather at start-up.

Steering System Vibrations and Harshness
Buzz
Buzz is a tactile rotary vibration felt in the steering wheel when steering inputs are slow. Buzz can also be called a grinding
feel and it is closely related to grunt and is caused by high system gain with low damping. Buzz is generally excited during
parking manoeuvres with low to medium speed steering input.

Buzz (Electrical)

A different steering buzz can be caused by pulse width modulated (PWM) electric actuators used in variable assist steering
systems. This buzz is felt by turning the ignition key to run without starting the engine and holding onto the steering wheel.
In extreme cases, the buzz can be felt with the engine running also.

Column/Steering Wheel Shake

Column shake is a low frequency vertical vibration excited by primary engine vibrations.

Nibble (Shimmy)

Power Steering - Steering Gear
Removal and Installation Published: 04-Jul-2013



CAUTIONS: Removal

Make sure that only the manufacturers' recommended four wheel alignment equipment is used.


Do not turn the steering wheel with the steering column lower shaft disconnected as damage to the clockspring and
steering wheel switches may occur.
NOTES:


Make sure the steering is in the straight ahead position.


RHD illustration shown, LHD is similar.

Some variation in the illustrations may occur, but the essential information is always correct.

1. Raise and support the vehicle.

2. Center the steering wheel.
Lock in position and remove the ignition key.

3. Remove the front wheels and tires.
For additional information, refer to: Wheel and Tire (204-04 Wheels and Tires, Removal and Installation).

4. Remove the air deflector.
For additional information, refer to: Air Deflector (501-02 Front End Body Panels, Removal and Installation).

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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