2010 JAGUAR XFR ABS

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.

JaguarDrive Control Sub-System Faults
If a fault occurs in a sub-system, the driver is alerted by the illumination of a warning indicator and/or an appropriate message
for that sub-system in the instrument cluster message center. No JaguarDrive Control message will be shown when a failed
sub-system displays its own message.

When a sub-system fault is present and the driver attempts to select a different JaguarDrive Control mode or at the next
ignition on cycle, a message 'WINTER MODE FAULT' or 'DYNAMIC MODE FAULT' will appear in the message center. This
generally implies that the JaguarDrive Control system has a fault, but only because a sub-system fault is preventing its
operation. This message will be displayed once per ignition cycle, but is repeated if a further selection is made by the driver
using the JaguarDrive Control buttons or at the next ignition on cycle.


NOTE: The message 'WINTER MODE FAULT' or 'DYNAMIC MODE FAULT' can also in very rare circumstances be generated
by a fault in the JaguarDrive Control module.

It is not possible for the JaguarDrive Control module to cause any fault behavior (warning indicator illumination or message
generation) in any of the sub-systems. Illumination of a sub-system warning indicator and/or a sub-system related message
will never be associated with a JaguarDrive Control module or JaguarDrive Control system fault.

The sub-system control modules can detect a fault with the CAN (controller area network) bus signal from the transmission
selector module. If a fault in the JaguarDrive Control system is detected, the sub-system control modules will operate in the
'special modes off' setting. The sub-system control modules will record a fault code for a failure of the JaguarDrive Control CAN signal. These faults can be retrieved using the Jaguar approved diagnostic tool and will provide useful information to indicate
investigation of the JaguarDrive Selector module or the CAN bus network. JaguarDrive Control System or Control Module Fault

If a fault occurs in the JaguarDrive Control system, all button icon LED (light emitting diode)'s will be turned off (background
illumination will remain on) and pressing of the JaguarDrive Control buttons is ignored. The instrument cluster message center
will display a message 'WINTER MODE FAULT' or 'DYNAMIC MODE FAULT' when the fault occurs, if the fault is present and the
driver attempts to select a special mode (if the control module is able to do this) or at the next ignition on cycle.

The JaguarDrive Control buttons and control module (JaguarDrive Selector module) are an integral unit. If a fault occurs in
either component, the whole unit will require replacement, however, this is extremely unlikely.
CAN Bus Faults

If a CAN bus fault exists and prevents JaguarDrive Control system operation, all of the JaguarDrive Control button icon LED's will be illuminated and rotation pressing of the JaguarDrive Control buttons is ignored.

If the instrument cluster does not receive a JaguarDrive Control system CAN bus message from the JaguarDrive Control module, the message 'SPECIAL MODE UNAVAILABLE' will be displayed when the fault occurs and will be repeated at every
ignition on cycle.
User Error

A special mode change while DSC or ABS is active (this includes ABS cycling) may be misinterpreted as a system fault.

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.

www.JagDocs.com

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

Does the brake pedal return to its original position? Yes
No action required, vehicle is OK.
No
GO to K2. K2: CHECK FOR BRAKE PEDAL BINDING 1 Disconnect the brake booster from the brake pedal. Check the brake pedal to ensure free operation. Is the brake pedal operating freely? Yes
Install a new brake booster as required. REFER to:
Brake Booster (206-07 Power Brake Actuation, Removal and Installation), Brake Booster - RHD (206-07, Removal and Installation).
Re-test the system for normal operation.
No
Repair or install new brake pedal. Re-test the system for normal operation. Component Tests

Brake Booster

1. Check all hoses and connections. All unused vacuum connectors should be capped. Hoses and their connections should
be correctly secured and in good condition with no holes and no collapsed areas. Inspect the valve on the brake booster
for damage.
2. Check the hydraulic brake system for leaks or low fluid.

3. With the automatic transmission in PARK, stop the engine and apply the parking brake. Pump the brake pedal several
times to exhaust all vacuum in the system. With the engine switched off and all vacuum in the system exhausted,
apply the brake pedal and hold it down. Start the engine. If the vacuum system is operating, the brake pedal will tend
to move downward under constant foot pressure. If no motion is felt, the vacuum booster system is not functioning.

4. Remove the vacuum hose from the brake booster. Manifold vacuum should be available at the brake booster end of the
hose with the engine at idle speed and the automatic transmission in PARK. Make sure that all unused vacuum outlets
are correctly capped, hose connectors are correctly secured and vacuum hoses are in good condition. When it is
established that manifold vacuum is available to the brake booster, connect the vacuum hose to the brake booster and
repeat Step 3. If no downward movement of the brake pedal is felt, install a new brake booster.

5. Operate the engine for a minimum of 10 seconds at a fast idle. Stop the engine and allow the vehicle to stand for 10
minutes. Then, apply the brake pedal with approximately 89 N (20lb) of force. The pedal feel (brake application) should
be the same as that noted with the engine running. If the brake pedal feels hard (no power assist), install a new valve
and then repeat the test. If the brake pedal still feels hard, install a new brake booster. If the brake pedal movement
feels spongy, bleed the brake system.
REFER to: Brake System Bleeding (206-00 Brake System - General Information, General Procedures). Brake Master Cylinder

Usually, the first and strongest indicator of anything wrong in the brake system is a feeling through the brake pedal. In
diagnosing the condition of the brake master cylinder, check pedal feel as evidence of a brake concern. Check for brake warning
lamp illumination and the brake fluid level in the brake master cylinder reservoir.
Normal Conditions
The following conditions are considered normal and are not indications that the brake master cylinder is in need of repair.

Modern brake systems are designed to produce a pedal effort that is not as hard as in the past. Complaints of light
pedal efforts should be compared to the pedal efforts of another vehicle of the same model and year.
The fluid level will fall with brake pad wear.

Abnormal Conditions

Changes in the brake pedal feel or brake pedal travel are indicators that something could be wrong in the brake system. The
diagnostic procedure and techniques use brake pedal feel, warning indicator illumination and low brake fluid level as indicators
to diagnosing brake system concerns. The following conditions are considered abnormal and indicate that the brake master
cylinder is in need of repair:

NOTE: Prior to carrying out any diagnosis, make sure the brake system warning indicator is functional.
Brake pedal goes down fast. This could be caused by an external or internal leak.
Brake pedal goes down slowly. This could be caused by an internal or external leak.
Brake pedal is low or feels spongy. This condition may be caused by no fluid in the brake master cylinder, reservoir cap
vent holes clogged or air in the hydraulic system.
Brake pedal effort is excessive. This may be caused by a bind or obstruction in the pedal/linkage, a faulty non-return
valve, booster or insufficient booster vacuum.
Rear brakes lock up during light pedal force. This may be caused by damaged brake pads, a partially applied parking
brake, a damaged ABS sensor or bearing failure.
Brake pedal effort erratic. This condition could be caused by the brake booster or incorrectly installed brake pads.
Brake warning indicator is on. This may be caused by low fluid level or float assembly damaged. www.JagDocs.com

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.

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).

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