abs module JAGUAR XFR 2010 1.G Owner's Guide
Page 532 of 3039
6 Oil temperature sensor 7 High speed CAN from suspension control module 8 CJB (central junction box)
System Operation
ELECTRONIC
DIFFERENTIAL
-
5.0L
SUPERCHARGER
VEHICLES
FROM
2010MY
The
multi-plate
clutch
prevents
excessive
differential
slip and
therefore
maximizes
the
traction
performance
of
the
vehicle.
This
is
fundamentally
different
from
'braked'
traction
control
systems,
which
can
only
counteract
differential
slip when it
occurs.
A
certain
amount
of
differential
slip is
required
to
allow
the
vehicle
to
turn
corners
and
to
remain
stable
under
control
of
the
ABS
(anti-lock
brake
system).
The
system
is
completely
automatic and
does
not
require
any
special
driver
input.
The
multi-plate
clutch
actively
controls
the
torque
flow
through
the
differential
and
optimizes
the
torque
distribution in
the
driveline.
The
clutch
biases
the
torque
from
the
differential
to
the
wheel
with the
higher
grip
and prevents
the
wheel
with the
lower
grip
from
spinning.
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Page 537 of 3039
bus allows the DLM to communicate with other systems on the vehicle.
A certain amount of differential slip is required to allow the vehicle to turn corners and to remain stable under control of the
ABS. The ADM monitors the driver's demands through primary vehicle controls and automatically sets the slip torque in the differential. The system is completely automatic and does not require any special driver input.
The differential strategy in the ADM includes:
A pre-loading function, increasing locking torque with increased driving torque.
A slip controller to decrease locking torque for optimum comfort, e.g. parking.
The ADM memorizes the position of the motor when the ignition is switched off.
CAN bus messages used by the ADM include wheel speed, steering angle, automatic transmission speed, temperature information, car configuration, axle ratios and mode inputs.
The ADM also sends messages via the CAN bus to tell other control modules on the network the status of the electronic differential. The clutch torque and default mode status are some of the main signals sent out by the ADM.
If the DLM or ADM are replaced, a Jaguar approved diagnostic system must be connected to the vehicle and the differential
self-calibration procedure must be performed. This procedure must also be performed if the motor or electronic differential is
replaced.
If a fault occurs with the electronic differential, the ADM, the DLM, or one of the required input signals, the ADM records an
error code and displays a warning in the message center.
The following messages can be displayed:
Message Description Chime E-DIFF NOT
AVAILABLE Differential temperature has reached the overheat threshold. System deactivated until temperature
returns within limits. Single E-DIFF FAULT Fault has occurred with electronic differential. System deactivated until fault rectified. Single
Page 648 of 3039
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.
Page 651 of 3039
Stoplamp Switch
The stoplamp switch is mounted on the brake pedal box. One of the prerequisites for releasing the parking brake is that the
foot brake is applied. The EPB module is able to determine the position of the footbrake by monitoring the status of the
stoplamp switch via a hardwired electrical connection.
The stoplamp switch also forms part of:
The ABS. Refer to: Anti-Lock Control - Stability Assist (206-09 Anti-Lock Control - Stability Assist, Description and Operation). The speed control system. For additional information, refer to:
Speed Control (310-03A, Description and Operation),
Speed Control (310-03B, Description and Operation),
Speed Control (310-03C, Description and Operation).
Page 668 of 3039
Published: 11-May-2011
Hydraulic Brake Actuation - Hydraulic Brake Actuation - Component Location
Description and Operation
NOTE: RHD (right-hand drive) installation shown, LHD (left-hand drive) installation similar.
Component Location
Item Description 1 Brake master cylinder and fluid reservoir 2 Brake pedal 3 Brake pipes 4 Stoplamp switch 5 ABS (anti-lock brake system) module/ HCU (hydraulic control unit) 6 Brake booster
Page 673 of 3039
1 LH (left-hand) front brake 2 RH (right-hand) rear brake 3 LH rear brake 4 RH front brake 5 Primary circuit inlet port 6 Secondary circuit inlet port The ABS module is located in the passenger side, rear engine bay and incorporates the HCU. The HCU is a four channel unit that modulates the supply of hydraulic pressure to the brakes under control of the ABS module.
The primary and secondary outlets of the master cylinder are connected to the primary and secondary circuits within the HCU. The primary circuit in the HCU has separate outlet ports to the RH front and LH rear brakes. The secondary circuit in the HCU has separate outlet ports to the LH front and RH rear brakes.
Page 674 of 3039
CAUTION: The ABS module and the HCU are a single unit and must not be separated.
HCU Schematic Diagram
Item Description 1 Brake booster 2 Primary circuit 3 Secondary circuit 4 HCU
Page 691 of 3039
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
Page 692 of 3039
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.
Page 694 of 3039
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: