2010 JAGUAR XFR sensor

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.

10.























11. NOTE: Left-hand shown, right-hand similar.

Special Tool(s): 303-588 Special Tool(s): 206-080 Special Tool(s): 206-081 Using the special tools, fully retract the brake
caliper piston.














12.
Repeat the above procedure on the opposite side.

Installation


1. NOTE: The brake pad wear sensor retaining tang must be
installed to the sensor prior to installation to the brake
pad.











2. To install, reverse the removal procedure.

3. Repeat the above procedure on the opposite side.

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.

6 Pulsation damper 7 Separation valve 8 Damping chambers 9 Separation valve 10 Shuttle valve 11 Hydraulic pumps 12 Motor 13 Shuttle valve 14 Pressure sensor - all vehicles 15 Low pressure accumulator 16 Check valve 17 Low pressure accumulator 18 Inlet valve 19 Inlet valve 20 Inlet valve 21 Inlet valve 22 Outlet valve 23 Outlet valve 24 Outlet valve 25 Outlet valve 26 Pressure sensors - vehicles fitted with adaptive speed control only 27 RH front brake 28 LH rear brake 29 RH rear brake 30 LH front brake www.JagDocs.com

Brake fluid Shell ESL Dot 4 Torque Specifications
Description Nm lb-ft lb-in Brake master cylinder primary pressure transducer 30 22 – Brake tubes to hydraulic control unit (HCU) 17 13 – Rear wheel speed sensor retaining bolt 6 – 53 Yaw rate sensor and accelerometer retaining nuts 7 – 62 Hydraulic control unit (HCU) retaining bolts 8 – 71 Steering wheel rotation sensor retaining screws 4 – 35 Steering column to lower shroud retaining screws 3 – 27 www.JagDocs.com

Published: 02-Sep-2011
Anti-Lock Control - Stability Assist - Anti-Lock Control - Stability Assist - Component Location
Description and Operation


NOTE: RHD (right-hand drive) installation shown, LHD (left-hand drive) installation similar.
Component Location



Item Description 1 ABS (anti-lock brake system) module 2 RH (right-hand) front wheel speed sensor 3 Instrument cluster 4 Steering angle sensor 5 Yaw rate and lateral acceleration sensor 6 RH rear wheel speed sensor 7 LH (left-hand) rear wheel speed sensor 8 LH front wheel speed sensor

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.

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

Control Diagram

NOTE: A = Hardwired; D = High speed CAN (controller area network) bus; N = Medium speed CANCAN bus; V = Private CAN bus.


Item Description 1 Battery 2 BJB (battery junction box) (250 A megafuse) 3 CJB (central junction box) 4 EJB (engine junction box) 5 LH (left-hand) front wheel speed sensor