Can bus JAGUAR XFR 2010 1.G Repair Manual

Symptom Possible Cause Action The parking brake will not
engage or release (with
parking brake warning
message)
Cables fouled, trapped or damaged
Cables incorrectly routed or installed
Rear lining wear
Actuator malfunction
Caliper malfunction
Check the rear and primary
cables for correct installation
and damage
Inspect the rear brake linings for
wear
Re-calibrate the parking brake,
refer to the calibration procedure
Check the rear service brake for
correct installation and operation No communication with the
parking brake module
Fuse
Module off Bus
CAN network error
Parking brake module fault
Check fuses
Ensure battery is fully charged
and in serviceable condition.
Check battery voltage at parking
brake module
Check CAN network using
manufacturer approved
diagnostic system 'Park brake Fault' displayed on
message center with
associated warning lamps
Parking brake system fault
Check the parking brake module
for DTCs and refer to DTC Index Brakes drag
Parking brake not re-calibrated after battery has
been disconnected or has been in a state of
discharge, or repairs have been carried out to
the rear service or parking brake system
Service brake system fault
Re-calibrate parking brake, refer
to the calibration procedure
Check the service brake for
correct operation DTC Index

For a list of diagnostic trouble codes that could be logged on this vehicle, please refer to Section 100-00.
REFER to: Diagnostic Trouble Code (DTC) Index - DTC: Electric Parking Brake (PBM) (100-00 General Information, Description and Operation).

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

Press and hold the DSC switch for less than 10 seconds.
The message center will temporarily display either Trac DSC or DSC ON.
The warning indicator in the instrument panel will illuminate while Trac DSC is selected.
The warning indicator will flash when DSC or Trac DSC is active.


NOTE: If cruise control is engaged, it will automatically disengage if DSC activates.

Refer to: Speed Control (310-03 Speed Control - 2.7L V6 - TdV6, Description and Operation).

Corner Brake Control

CBC (corner brake control) influences the brake pressures, below and within DSC and ABS thresholds, to counteract the yawing moment produced when braking in a corner. CBC produces a correction torque by limiting the brake pressure on one side of the
vehicle.

Electronic Brake Force Distribution

EBD (electronic brake force distribution) limits the brake pressure applied to the rear wheels. When the brakes are applied, the
weight of the vehicle transfers forwards, reducing the ability of the rear wheels to transfer braking effort to the road surface.
This may cause the rear wheels to slip and make the vehicle unstable.

EBD uses the ABS braking hardware to automatically optimize the pressure to the rear brakes, below the point where ABS is normally invoked.


NOTE: Only the rear brakes are controlled by the EBD function.
Electronic Traction Control

ETC (electronic traction control) attempts to optimize forward traction by reducing engine torque, or by applying the brake of a
spinning wheel until traction is regained.

ETC is activated if an individual wheel speed is above that of the vehicle reference speed (positive slip) and the brake pedal is
not pressed. The brake is applied to the spinning wheel, allowing the excess torque to be transmitted to the non-spinning
wheel through the drive line. If necessary, the ABS module also sends a high speed CAN bus message to the ECM to request a reduction in engine torque.

When the DSC function is selected off using the DSC switch, the braking and engine torque reduction features are both
disabled, except when the JaguarDrive control is in winter mode. When the JaguarDrive control is in winter mode, selecting the
DSC function off retains the braking and engine torque reduction features, but reduces intervention levels compared to DSC
and Trac DSC modes.

Emergency Brake Assist

EBA (emergency brake assist) assists the driver in emergency braking situations by automatically increasing the applied
braking effort. The ABS module invokes EBA when: The brake pedal is rapidly pressed.
The brake pedal is pressed hard enough to bring the front brakes into ABS operation.
When the brake pedal is rapidly pressed, the ABS module increases the hydraulic pressure to all of the brakes until the threshold for ABS operation is reached. This action applies the maximum braking effort for the available traction. The ABS module monitors for the sudden application of the brakes, using inputs from the brake pedal switch and from the pressure
sensor within the HCU (hydraulic control unit). With the brake pedal pressed, if the rate of increase of hydraulic pressure
exceeds the predetermined limit, the ABS module invokes emergency braking.
When the brake pedal is pressed hard enough to bring the front brakes into ABS operation, the ABS module increases the hydraulic pressure to the rear brakes up to the ABS threshold.
EBA operation continues until the driver releases the brake pedal, sufficiently for the hydraulic pressure in the HCU to drop below a threshold value stored in the ABS module.
Engine Drag-Torque Control
EDC (engine drag-torque control) prevents wheel slip caused by any of the following: A
sudden decrease in engine torque when the accelerator is suddenly released.
A downshift using the Jaguar sequential shift function on automatic transmission vehicles.

When the ABS module detects the onset of wheel slip without the brakes being applied, the ABS module signals the ECM via the high speed CAN bus to request a momentary increase in engine torque.
Understeer Control

Understeer Logic Control is a proactive system which monitors the vehicle for understeer by comparing signals from the yaw
rate and lateral acceleration sensor with signals from the steering angle sensor and wheel speed sensors. www.JagDocs.com

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

center and an amber warning indicator will illuminate.
Refer to: Information and Message Center (413-08 Information and Message Center, Description and Operation).

As the wheel speed sensors are active devices, a return signal is available when the road wheels are not rotating. This enables
the ABS module to check the condition of the speed sensors while the vehicle is stationary.
Steering Angle Sensor



The steering angle sensor measures the steering wheel angle and the rate of change of the steering wheel angle. These
measurements are received by the ABS module and broadcast on the high speed CAN bus for use by other systems.
The steering angle sensor is mounted on the steering column upper shroud mounting bracket, immediately behind the
multifunction switches, and is secured by 2 screws. A fly lead connects the sensor to the passenger compartment wiring
harness via a 4 pin multiplug.
The sensor is housed in a 'U' shaped plastic casing and contains two offset LED (light emitting diode)s facing two detectors.

An encoder ring is mounted on the inner steering column shaft and intersects the LEDs and detectors. The encoder ring contains 60 slots which break and restore the light beams between the LEDs and the detectors as the steering wheel is

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).

Stoplamp Switch


The stoplamp switch is mounted on the brake pedal box and is connected to the vehicle harness via a four pin multiplug.

When the brake pedal is pressed, the switch contacts close. This allows a hard wired signal feed to be sent to the ECM. A stoplamp switch status message is then sent from the ECM to the ABS module on the high speed CAN bus. The ABS module is then able to control braking force accordingly in conjunction with the HCU.

NOTE: The stoplamp switch also forms part of the speed control system.
For additional information, refer to:

Speed Control (310-03 Speed Control - 2.7L V6 - TdV6, Description and Operation),
Speed Control (310-03 Speed Control - 3.0L NA V6 - AJ27, Description and Operation),
Speed Control (310-03 Speed Control - 4.2L NA V8 - AJV8/4.2L SC V8 - AJV8, Description and Operation). www.JagDocs.com

Published: 20-May-2014
Steering Column - Steering Column - System Operation and Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired; D = High speed CAN bus; N = Medium speed CAN bus



Item Description 1 Battery 2 BJB (battery junction box) - Megafuse (175A) 3 RJB (rear junction box) 4 Electric steering column lock 5 High Speed CAN (controller area network) bus to other vehicle systems 6 CJB (central junction box)