2010 JAGUAR XFR lock

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

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:

Item Description 1 ABS warning indicator (USA only) 2 ABS warning indicator (Canada and Mexico only) 3 ABS warning indicator (all except USA, Canada and Mexico) 4 DSC warning indicator 5 Brake warning indicator (USA only) 6 Brake warning indicator (all except USA) The instrument cluster and message center contains warning indicators and warning messages to display the operating status
of the anti-lock control - stability assist functions. The warning indicators and messages provide a visual notification of either
a system warning or information indication to the driver. There are three warning indicators on the instrument cluster, which
vary dependant on market, and several types of message relating to the anti-lock control - stability assist functions. The DSC
OFF message is accompanied by an audible warning.
The following anti-lock control - stability assist warning indicators are installed in the instrument cluster:
An amber ABS warning indicator. A red brake warning indicator.
An amber DSC warning indicator.

Refer to: Instrument Cluster (413-01 Instrument Cluster, Description and Operation) / Information and Message Center (413-08
Information and Message Center, Description and Operation). Instrument Cluster Warning Indicators

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).

Published: 11-May-2011
Anti-Lock Control - Stability Assist - Anti-Lock Brake System (ABS) Module
Removal and Installation

Removal


1. NOTE: The anti-lock braking system (ABS) module mounted to the
hydraulic control unit (HCU) cannot be serviced separately. If the ABS
module requires replacement, the unit must be replaced as a complete
assembly.
Remove the HCU.
For additional information, refer to: Hydraulic Control Unit (HCU)
(206-09, Removal and Installation).

Installation

1. Install the HCU.
For additional information, refer to: Hydraulic Control Unit (HCU)
(206-09, Removal and Installation).
www.JagDocs.com

Anti-Lock Control - Stability Assist - Front Wheel Speed Sensor
Removal and Installation

Removal Published: 11-May-2011


1. WARNING: Make sure to support the vehicle with axle stands.
Raise and support the vehicle.

2. Refer to: Fender Splash Shield (501-02 Front End Body Panels, Removal and Installation).


3. NOTE: LH illustration shown, RH is similar.























4. NOTE: LH illustration shown, RH is similar.