2010 JAGUAR XFR ESP

2 Main piston 3 Tube 4 Bypass valve (closed) 5 Piston and rod assembly ACCELEROMETERS


Three accelerometers are used in the adaptive dynamics system. The accelerometers are located as follows:
One each on the rear edge of the radiator support panel.
One in the luggage compartment, in the rear LH corner adjacent to the rear lamp assembly.
The accelerometers measure acceleration in the vertical plane and output a corresponding analogue signal to the adaptive
damping module. The algorithms in the adaptive damping module calculate the heave, pitch and roll motions of the vehicle,
which are used by the module to control road induced body modes.

Each accelerometer is connected to the adaptive damping module via three wires, which supply ground, 5 V supply and signal
return.

The sensing element comprises a single parallel plate capacitor, one plate of which moves relative to the other dependant on
the force (acceleration) applied. This causes the capacitance to change as a function of applied acceleration. This capacitance
is compared with a fixed reference capacitor in a bridge circuit and the signal is processed by means of a dedicated integrated
circuit to generate an output voltage that varies as a function of applied acceleration. The sensors output a signal voltage of
approximately 1 V/g ± 0.05 V/g.

SUSPENSION HEIGHT SENSORS



Four suspension height sensors are used in the adaptive dynamics system, two for the front suspension and two for the rear
suspension. A front suspension height sensor is attached to each side of the front subframes and connected by a sensor arm
and sensor link to the related lower lateral arm of the front suspension. A rear suspension height sensor is attached to each
side of the rear subframe and connected by a sensor arm and sensor link to the related upper control arm of the rear
suspension. On each suspension height sensor, the sensor arm and sensor link convert linear movement of the suspension into
rotary movement of the sensor shaft.
The sensors are also used for the static dynamic headlamp leveling system on vehicles fitted with xenon headlamps.

The suspension height sensors measure suspension displacement at each corner of the vehicle and output a corresponding
analogue signal to the adaptive damping module. The algorithms in the adaptive damping module calculate the position,
velocity and frequency content of the signals and use the results for wheel control.
Each suspension height sensor is connected to the adaptive damping module via three wires, which supply ground, 5 V supply

Published: 11-May-2011
Ride and Handling Optimization - Ride and Handling Optimization - System
Operation and Component Description
Description and Operation



JAGUARDRIVE CONTROL OPERATION

Engine Management System System Operation

The Engine Management System (EMS) varies the accelerator pedal maps to change the amount of torque per percentage of
pedal travel. The EMS can also change the accelerator pedal response to control the allowed torque change relative to the
speed of pedal travel.

Each driving mode uses a combination of operating parameters for each sub-system. Changing between driving modes initiates
a different set of operating characteristics, which will be noticeable to the driver. The driver will notice differences in engine
response when, for example, the accelerator pedal is held in a constant position and the driving mode is changed from Winter
to Dynamic, the driver will notice the torque and engine speed increase. Similarly, if the mode is changed from Normal or
Dynamic to Winter the driver will notice a reduction in torque and engine speed.


NOTE: The change in torque and engine speed can take approximately 30 seconds and care must be taken not to confuse
the JaguarDrive Control system operation with an EMS fault.
Transmission Control

The TCM (transmission control module) changes the shift maps for the JaguarDrive Control mode selected. This changes the
shift points providing early or late upshifts and downshifts. For example, on slippery surfaces in Winter mode the transmission
will select 2nd gear for starting from a standstill on a flat surface to minimize wheel slip.
Anti-lock Braking System Control

The ABS (anti-lock brake system) module controls several vehicle functions and adjusts the operating parameters of these
functions to optimize the selected JaguarDrive Control mode. Traction control uses different slip/acceleration thresholds to
improve traction and vehicle composure. For example, the system sensitivity is increased on slippery surfaces to reduce wheel
spin.

If TracDSC is selected or DSC is switched off, then subsequently the JaguarDrive Control mode is changed, DSC is automatically
switched back on (or to TracDSC for Dynamic mode).

The stability control uses different threshold values for the selected mode, reducing the requirement for the driver to change
the DSC system mode for optimum performance in various driving scenarios.
Incorrect Mode Usage

Selection of an inappropriate mode is discouraged in the following ways:

The active mode icon is continually displayed in the instrument cluster message center
In any special mode, when the ignition has been in the off position continuously for more than 6 hours, the JaguarDrive
Control system defaults to the special modes off (DSC on).

Selection of an inappropriate mode for the conditions will not endanger the driver or immediately cause damage to the vehicle.
Continued use of an inappropriate mode may reduce the life of some components. The driver may notice a different vehicle
response, with the engine and transmission responses being different than in the special modes off.
Driver Information

The instrument cluster contains a message center, which displays vehicle information to the driver. The message center
contains the JaguarDrive Control mode icons, which display the currently selected mode. If no symbol is displayed, no special
mode is selected and the system is in special modes off.

Any required changes to the subsystems are also passed to the driver in the form of warning illumination in the instrument
cluster or appropriate messages in the message center, DSC off for example.

In Dynamic mode when the transmission is in manual mode, the gear information is displayed in amber when the appropriate
engine speed is reached for optimum sporty change point.

DIAGNOSTICS

JaguarDrive Control relies on the correct functionality of the sub-systems. If one of the sub-systems develops a fault, the
JaguarDrive Control system will not function, even though the fault is not in the JaguarDrive Control system.

The JaguarDrive Selector module and rotary control should only be investigated if there are no apparent faults in any of the
sub-systems. If a fault in a sub-system is subsequently corrected, the JaguarDrive Control system will function normally after
an ignition on and off cycle.

BRAKE CALIPERS System Operation

When hydraulic pressure is supplied to the caliper, the pistons extend to force the inner pad against the brake disc. The caliper
reacts and slides along two guide pins to bring the outer pad into contact with the brake disc.

BRAKE PAD WEAR SENSORS

When a brake pad incorporating a brake pad wear sensor is approximately 75% worn, the sensor wire within the pad material
is worn through and the brake pad wear sensor goes open circuit. When the instrument cluster detects the open circuit, it
illuminates the amber LED (light emitting diode) in the brake warning indicator, displays an appropriate warning in the
message center and sounds a warning chime.
Refer to: Instrument Cluster (413-01 Instrument Cluster, Description and Operation).

NOTE: A new pad wear sensor lead must be fitted whenever the brake pads are changed, irrespective of the brake pad
warning sensor being triggered.



BRAKE CALIPERS Component Description

Each caliper is mounted within a fixed carrier that is secured to the front wheel knuckle with two bolts. The inboard brake pad
of the LH (left-hand) brake incorporates a wear sensor.

Each outboard brake pad is installed with a pressed steel anti-rattle spring. On SC (supercharger) vehicles, a badge with the
'R' symbol is formed on the anti-rattle spring.

BRAKE PAD WEAR SENSORS

The brake pad wear sensor is wired in series with a wear sensor on the RH (right-hand) rear brake and the instrument cluster.
If the thickness of one of the brake pads connected to a wear sensor decreases to a predetermined limit, the instrument
cluster illuminates the brake warning indicator.

BRAKE CALIPERS System Operation

When hydraulic pressure is supplied to the caliper, the pistons extend to force the inner pad against the brake disc. The caliper
reacts and slides along two guide pins to bring the outer pad into contact with the brake disc.

BRAKE PAD WEAR SENSORS

When a brake pad incorporating a brake pad wear sensor is approximately 75% worn, the sensor wire within the pad material
is worn through and the brake pad wear sensor goes open circuit. When the instrument cluster detects the open circuit, it
illuminates the amber LED (light emitting diode) in the brake warning indicator, displays an appropriate warning in the
message center and sounds a warning chime.
Refer to: Instrument Cluster (413-01 Instrument Cluster, Description and Operation).

NOTE: A new pad wear sensor lead must be fitted whenever the brake pads are changed, irrespective of the brake pad
warning sensor being triggered.



BRAKE CALIPERS Component Description

Each caliper is mounted within a fixed carrier that is secured to the rear wheel knuckle with two bolts. Each outboard brake pad
is installed with a wire anti-rattle spring.

The brake calipers on SC (supercharger) vehicles are painted and also include a logo badge, secured with two screws, which
must be removed in order to change the brake pads.
The inboard brake pad of the RH (right-hand) brake incorporates a wear sensor.

BRAKE PAD WEAR SENSORS

The brake pad wear sensor is wired in series with a wear sensor on the LH (left-hand) front brake and the instrument cluster. If
the thickness of one of the brake pads connected to a wear sensor decreases to a predetermined limit, the instrument cluster
illuminates the brake warning indicator.

7 Instrument cluster 8 Parking brake switch 9 Parking brake actuator


Static Apply System Operation

The EPB module receives a vehicle speed signal from the ABS (anti-lock brake system) module on the high speed CAN bus. If the parking brake switch is pulled to the 'Apply' position and vehicle speed is less than 2 mph (3 km/h), the EPB module will
instigate its 'Static Apply' mode and drive the actuator to apply full parking brake force to the rear wheels.

The EPB module monitors the current drawn by the actuator and compares this to information held within its configuration
software to determine when full braking force has been applied.

Dynamic Apply

There are two 'Dynamic Apply' modes; low speed dynamic and high speed dynamic. The low speed dynamic mode operates at
speeds between 2 mph (3 km/h) and 20 mph (32 km/h). The high speed dynamic mode operates at speeds above 20 mph (32
km/h).

If the parking brake switch is pulled up to the 'Apply' position and vehicle speed is within the low speed dynamic range, the
EPB module drives the actuator to apply full parking brake force to the rear wheels.

If the parking brake switch is pulled up to the 'Apply' position and vehicle speed is within the high speed dynamic range, the
EPB module will apply braking force to the rear wheels at a slower rate until full braking load is reached or the switch is
released. The rate with which braking force is applied is controlled by the EPB module, which monitors both current drawn by
the actuator and positional information from the actuator hall sensor and compares this to information held within its
configuration software.

Drive Away Release

The EPB module will initiate its 'Drive Away Release' function and automatically release the parking brake if the following
conditions are detected:
The engine is running.
Drive , or reverse is selected.
Positive throttle movement is detected.

The EPB module receives messages of gear selector position and throttle angle over the high speed CAN bus from the TCM (transmission control module) and the ECM (engine control module) respectively.

Release from Park

The EPB module will initiate its 'Release from Park' function and automatically release the parking brake if the gear selector is
moved from Park to any position except Neutral.

Repairs

Before carrying out any work on the parking brake system, the Jaguar approved diagnostic system must be connected and the
'parking brake unjam' routine run. The routine can be found in the 'Vehicle Configuration' area, under the 'Set-up and
Configuration' menu. After any work has been carried out on the parking brake, the system will require resetting.


CAUTION: Do not use the 'Emergency Release' tool to allow work to be carried out on the parking brake. Work can only be
carried out on the parking brake system after the 'parking brake unjam' routine has been run.

Resetting

If the electrical supply is disconnected from the EPB module, the actuator will loose its position memory. On battery
re-connection and ignition on, 'APPLY FOOT AND PARK BRAKE' will be displayed in the instrument cluster message center
indicating the parking brake requires resetting.
Refer to: Parking Brake (206-05, Diagnosis and Testing).

Operating Voltages

The EPB module will only operate the actuator if the power supply from the battery is between 9 V and 16 V. At any voltage
within this range, the actuator is able to fully tighten and release the brake cables. If the power supply falls outside of the
range, a fault code is stored in the EPB module and can be retrieved using the Jaguar approved diagnostic system.

Published: 11-May-2011
Anti-Lock Control - Stability Assist - Anti-Lock Control - Stability Assist - Overview
Description and Operation

Overview

The ABS (anti-lock brake system) and DSC (dynamic stability control) system features a Bosch modulator, which is an
integrated four-channel HCU (hydraulic control unit) and ABS module. The unit is located in the rear of the engine compartment on the passenger side, and is installed in the brake hydraulic circuit between the brake master cylinder and the four brake
calipers.

The ABS module is connected to the high speed CAN (controller area network) bus, and actively interacts with other vehicle system control modules and associated sensors to receive and transmit current vehicle operating information.

When required, the ABS module will actively intervene and operate the HCU during braking or vehicle maneuvers to correct the vehicle attitude, stability, traction or speed. During incidents of vehicle correction, the ABS module may also request the ECM (engine control module) to control engine power in order to further stabilize and correct the vehicle.
To provide full system functionality, the ABS and DSC system comprise the following components: DSC switch.
Four wheel speed sensors.
Steering angle sensor.
Yaw rate and lateral acceleration sensor.
Stoplamp switch.
Instrument cluster indicator lamps.
Integrated ABS module and HCU. Brake booster vacuum sensor (3.0L vehicles only).

Two variants of ABS module are available, Bosch ESP®8.1 and Bosch ESP®plus8.1. The Bosch ESP®plus8.1 system is fitted to vehicles with ACC (adaptive cruise control) and incorporates a new feature to Jaguar known as 'electronic brake prefill'.

Electronic brake prefill, 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. When the ECM detects rapid throttle lift off it signals the ABS module which controls the HCU to apply a low brake pressure to assist in a quicker brake application.

NOTE: All vehicles with ACC are supported by the Bosch ESP®plus8.1 system.

The ABS provides the following brake functions that are designed to assist the vehicle or aid the driver: ABS. DSC, including Trac DSC.
CBC (corner brake control).
EBD (electronic brake force distribution).
ETC (electronic traction control).
EBA (emergency brake assist).
EDC (engine drag-torque control).
Understeer control.
Electronic brake prefill (vehicles with ACC only).
Brake vacuum assist (3.0L vehicles only).

All the brake functions listed are automatically active when the ignition is in power mode and the engine is running. The DSC
system can be selected to off using the DSC switch.


WARNING: Although the vehicle is fitted with DSC, it remains the drivers responsibility to drive safely according to the
prevailing conditions.

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.

compartment, forward of the front suspension housing.

On petrol engine vehicles, a fluid cooler is located in front of the engine cooling radiator. Diesel models do not have a fluid
cooler.

Servotronic 2 adds electronic control and speed sensitive steering to the steering gear. The Servotronic 2 feature provides easy
and comfortable steering operation when parking, improved 'road feel' at increased road speeds and adds an integrated,
positive center feel feature which optimises steering wheel torque during high speed driving. The Servotronic 2 system is
controlled by software which is incorporated into the instrument cluster. The software responds to road speed signals and
controls the power assistance via a transducer valve located on the steering gear valve housing.