2009 JAGUAR XF Message centre

Brakes
144

PRINCIPLE OF OPERATION
Brake pads
Brake pads require a period of bedding in when
new. Drive with extra caution for the first
500 km (300 miles) to avoid the need for heavy
braking.
Brake pad wear warning
When the brake pads are wearing low, the
warning message BRAKE PADS LOW is
displayed in the message centre. Arrange for
your vehicle to be se en by your Dealer/
Authorised Repairer at the earliest opportunity.
Wet conditions
Driving through heavy ra in or water can have
an adverse effect on braking efficiency. Under
such circumstances, it is recommended that
you lightly a pply the brakes intermittently to
dry the brakes.
ABS warning indicator
If this amber warning indicator
illuminates while driving and/or
ABS FAULT is displayed in the
message centre, drive with extra caution, avoid
heavy braking where possible, and seek
qualified assistance as soon as possible.
If this red warning indicator
illuminates while driving and/or the
message LOW BRAKE FLUID is
displayed in the message centre, check the
brake fluid level at the earliest opportunity and
top-up as required. See BRAKE FLUID CHECK
(page 206).
HINTS ON DRIVING WITH ABS
ABS (Anti-Lock Braking System) allows
maximum brake pressure, and thus maximum
braking efficiency, to be applied, and prevents
the road wheels locking. This allows the driver
to retain steering control during heavy braking
under most road conditions.
ABS optimises tyre to road adhesion under
maximum braking conditions, though it cannot
provide increased cornering ability.
WARNINGS
Do not rest your foot on the brake
pedal whilst the vehicle is in motion.
This may cause a light application of
the brakes, which can result in overheating,
reduced brake performance, and excessive
brake wear.
Never allow the vehicle to coast
(freewheel) with the engine turned
off. The engine must be running to
provide full braking assistance. The brakes will
still function with the e ngine off, but far more
pressure will be required to operate them.
If the red brake warning indicator
illuminates, safely bring the vehicle to
a stop, as quickly as possible. Seek
qualified assistance before proceeding.
Never place non-approved floor
matting or any ot her obstructions
under the brake pedal. This restricts
pedal travel and braking efficiency.
WARNINGS
ABS cannot overcome the physical
limitations of braking distance. Nor
can it overcome the lack of grip on a
road surface (e.g. aquaplaning on water).
Braking distance is increased on a
slippery surface. This applies to all
vehicles, even those fitted with ABS.
The driver should not be tempted to
take risks when driving, in the hope
that ABS will correct errors of
judgement. In all cases it remains the driver's
responsibility to driv e with due care and
attention, payi ng particular attention to the
effects of speed, weather, road conditions etc.

145
Brakes

During emergency braking conditions ABS
constantly monitors the speed of each wheel.
ABS varies the brake pressure to individual
wheels, according to the grip available. The
constant alteration of brake pressure can be
felt as a pulsing sensation through the brake
pedal. This is not a caus e for concern, as it is
designed to demonstrate to the driver that ABS
is operating.
ABS braking techniques
For optimum ABS performance, these
instructions on braking techniques during ABS
operation should be followed:
• Do not release the brake pressure when
the pulsating effect is felt. Maintain a
constant pressure until the manoeuvre is
completed.
• To familiarise y ourself with the feel of the
brake pedal during ABS braking, practise
an emergency stop pr ocedure, always
making sure it is safe to do so. With the
seat belts fitted to all occupants, drive the
vehicle at 32 km/h (20 mph) and brake
sharply.
• ABS enables the driver to steer around
obstacles during em ergency braking.
However, the consequences of turning
sharply at high speed cannot be overcome
by the ABS.
• Do not attempt to pump the brakes to
avoid skidding, as this can interfere with
ABS operation. The ABS will not allow the
wheels to skid under normal road
conditions.
• The ABS will tend to keep the vehicle
straight during braki ng. Because braking
distances may increase under certain road
conditions, it is nece ssary to plan and
make turning manoeuvres as early as
possible.
Electronic Brakeforce Distribution (EBD)
EBD balances the distribution of braking forces
between the wheels on the front and rear axles,
to maintain maximum braking under all vehicle
loading conditions.
For example; Under light loads, EBD applies
less braking effort to the rear wheels, to
maintain stability. Conv ersely, it allows full
braking effort to the rear wheels when the
vehicle is towing or is heavily laden.
A fault with the EBD system is
indicated by illumination of the red
brake warning indicator and the
message EBD FAULT is displayed in the
message centre. Gently stop the vehicle, as
soon as safety permit s, and seek qualified
assistance.

Brakes
146

Emergency Brake Assist (EBA)
The EBA system measures the rate at which the
brake pressure increases. If the system detects
an emergency braking situation, EBA
automatically init iates full braking effect. This
can reduce stopping dist ances in critical
situations.
EBA stops operating as soon as the brake pedal
is released.
EBA is part of the Dynamic Stability
Control (DSC) system and a fault
with the EBA system is indicated by
the amber DSC warning indicator illuminating
and DSC NOT AVAILABLE (with amber
backlight) displaying in the message centre.
Seek qualified assistan ce as soon as possible.
Brake vacuum assist
(V6 petrol models only)
When the engine is cold and/or engine vacuum
is low, Brake vacuum assist provides additional
brake pedal assistance. When the function is
operating, a pulsation ma y be felt through the
brake pedal - this is not a cause for concern.
A fault is indicate d by the message BRAKE
ASSIST FAULT (with amber backlight)
appearing in the message centre. Increased
brake pedal effort may be required to slow the
vehicle when the engine is cold and/or engine
vacuum is low. Seek qualified assistance.
ELECTRIC PARKING BRAKE (EPB)
The switch which operate s the parking brake is
mounted on the centre c onsole to the rear of
the gear selector.
To engage the parking brake (1): Pull the
parking brake switch up wards and release. The
switch will return to the neutral position. The
Parking brake warning and Brake fluid low
warning indicator on the instrument panel will
illuminate.
The Drive Away Release feature allows the
parking brake to release automatically as the
vehicle is driven away.
To disengage the parking brake (2): With the
ignition system on or with the engine running,
apply the foot brake and press the parking
brake switch down.
If the parking brake is a pplied while the vehicle
is stationary and D or R is selected, applying
the throttle will auto matically release the
parking brake.
The parking brake is also automatically
released when the gear selector is moved from
the P position.
WARNING
The EBA system is an additional
safety system; it is not intended to
relieve the driver of his or her
responsibility for exercising due care and
attention when driving.12
E95148

147
Brakes

If the parking brake is inadvertently applied
when the vehicle is moving at above 3 km/h
(1.8 mph), PARK BRAKE APPLIED is displayed
in the message centre, the warning indicator in
the instrument panel will illuminate and a
warning chime will sound.
If the parking brake is a pplied whilst the vehicle
is moving, releasing the switch will disengage
the parking brake. The parking brake cannot be
applied when the vehicle is moving, if the
accelerator pedal is pressed.
Note: If the vehicle is in motion, the parking
brake should only be used as an emergency
brake.
The warning indicator in the instrument panel
will remain on for a short time, if the parking
brake is applied when the ignition system is
reverted to the convenience mode.
If a fault in the system is detected,
the amber brake warning indicator
will illuminate and PARK BRAKE
FAULT or CANNOT APPLY PARK BRAKE will
be displayed in the message centre. Seek
qualified assistance as soon as possible.
If the battery has been discharged or
disconnected, APPLY FOOT AND PARK BRAKE
will be displayed in the message centre when
the ignition is next switched on. Depress the
foot brake and pull the parking brake switch up
to apply the parking brake. This is required to
reset the parking brake system. The parking
brake will now function correctly.
CAUTION
Always apply the parking brake when
the vehicle is parked.

Cruise control
158

Message centre information displays
Message Warning IndicatorPriority
Indicator Meaning
CRUISE OVERRIDE None None Driver is pressing the accelerator pedal,
overriding Cruise Control function.
Message will disappear when accelerator
pedal is released and Cruise Control
speed is resumed.
CRUISE CANCELLED None None Driver has cancelled cruise control or is
braking.
CRUISE NOT AVAILABLE None None Cruise C ontrol or Adaptive Cruise Control
malfunction.

Adaptive cruise control (ACC)
160

Setting the speed
Accelerate as normal until the required speed is
reached.
Rotate the speed adjustment control upwards
(+) to store the vehicle speed in the memory
and engage the system.
The set speed will be displayed on the message
centre (e.g. SETSPEED 80 KM/H (50 MPH) ).
Changing the speed
There are three ways to change the set speed:
•Accelerate or brake to the desired speed
then rotate the speed adjustment control
upwards ( +).
• Increase or decrease the speed by rotating
the speed adjustment control upwards ( +)
or downwards ( -), until the required set
speed is shown on the message centre.
The vehicle speed will gradually adjust to
the selected speed.
• Increase or decrease the speed in steps of
2 km/h (1 mph) by rotating the speed
adjustment control upwards (+) or
downwards ( -) briefly until the desired
speed is obtained.
ACC operates between approximately 30 km/h
and 180 km/h (18 mph and 112 mph)
dependent on the c ountry specification.
Set speeds outside th is range will not be
captured. The ACC may apply the brakes to slow down
the vehicle to the new set speed. The new set
speed will be displayed on the message centre
until ACC is cancelled.
Follow mode gap settings
Once a set speed has been selected, the driver
can release the accelerator and the set road
speed will be maintained.
When a vehicle ahead enters the same lane or
a slower vehicle is ahead in the same lane, the
vehicle speed will be adjusted automatically
until the gap to the vehicle ahead corresponds
to the default gap setting (gap level 3). The
vehicle is now in
follow mode.
The amber warning indicator in the
instrument panel will be
illuminated.
The message centre will display the gap set.
E97091
WARNING
When in follow mode, the vehicle will
not decelerate automatically to a stop,
nor will the vehicle always decelerate
quickly enough to avoid a collision, without
driver intervention.
E91497

161
Adaptive cruise control (ACC)

The vehicle will then maintain the constant time
gap to the vehicle ahead until:
•The vehicle ahead accelerates to a speed
above the set speed.
• The vehicle ahead moves out of lane or out
of view.
• A new gap distance is set.
If necessary, the vehicle brakes will be
automatically applied to slow the vehicle to
maintain the gap to the vehicle in front.
The maximum braking which is applied by the
ACC system is limited and can be overridden by
the driver applying the brakes, if required.
Note: Driver braking will cancel ACC.
If the ACC system predicts that its maximum
braking level will not be sufficient, then an
audible warning will sound while the ACC
continues to brake. DRIVER INTERVENE will be
displayed on the message centre. The driver
should take immediate action.
When in follow mode, the vehicle will
automatically return to the set speed when the
road ahead is clear, for instance when:
• The vehicle in front accelerates or changes
lane.
• The driver changes lane to either side or
enters an exit lane.
The driver should intervene if appropriate.
Changing the follow mode set gap
The gap from the vehicle ahead can be
decreased or increased by rolling the
thumbwheel on the stee ring wheel. Four gap
settings are available and the selected gap
setting will be displaye d on the message centre
when either ACC button is pressed. Each gap level is indicated by an
additional
chevron in front of th e vehicle icon in the
message centre (one chevron (gap level 1)
being the shortest, four chevrons (gap level 4)
being the longest). A fter the ignition is
switched on, the default gap (gap level 3) will
be automatically selected ready for ACC
operation.
Note: When the ignition is switched off, the
gap setting will revert to the default setting
(gap level 3) when switched on again.
Note: It is the driver’s responsibility to select a
gap appropriate to the driving conditions.
Overriding the speed and follow mode
The set speed and gap ca n be overridden by
pressing the accelerator pedal when cruising at
constant speed or in follow mode. If the vehicle
is in follow mode, the instrument warning
indicator will go out when the ACC is
overridden by the driver using the accelerator
and CRUISE OVERRIDE will be displayed on
the message centre. When the accelerator is
released the ACC functi on will operate again
and vehicle speed will decrease to the set
speed, or a lower spee d if follow mode is
active.
WARNING
Whenever the driver is overriding the
ACC by depressing the accelerator
pedal, the ACC will not automatically
apply the brakes to ma intain separation from
any vehicle ahead.

Adaptive cruise control (ACC)
162

Automatic low speed switch off
If the speed of the vehicle decreases below
30 km/h (18 mph), the ACC system will be
automatically switched off and the instrument
warning indicator will go out.
If the brakes were being applied by the ACC
system, they will be slowly released.
This will be accompanied by an audible
warning, and DRIVER INTERVENE will be
displayed on the message centre. The driver
must take control.
Automatic switch off
ACC will disengage, but not clear the memory
when;
• the CANCEL button ( 3) is pressed
• the brake pedal is pressed
• Neutral ( N), Park ( P) or Reverse ( R) gear
positions are selected
• Dynamic Stability Control activates.
ACC will disengage, and clear the memory
when;
• the ignition system is switched off
• maximum vehicle speed is reached
• a fault occurs in the ACC system.
Resuming the speed and follow mode
By pressing the RESUME button (4) after ACC
has been cancelled, for example, after braking,
the ACC will become active again provided that
the set speed memory has not been erased.
The original set speed will be resumed (unless
a vehicle ahead causes the follow mode to
become active) and the set speed will be
displayed in the message centre for four
seconds.
Hints on driving with ACC
The system acts by regulating the speed of the
vehicle using engine c ontrol and the brakes.
Gear changes may occur in response to
deceleration or acceleration whilst in ACC.
ACC is not a collision avoidance system.
However, during some situations the system
may provide the driver with an indication that
intervention is required.
An audible alarm will sound, accompanied by
the message DRIVER INTERVENE if the ACC
detects:
• A failure has occurred whilst the system is
active
• That using maximum ACC braking only is
not sufficient.
Note: ACC operates when the gear selector
lever is in position S or D.
Note: When engaged, the accelerator pedal
rests in the raised position. Fully release the
pedal to allow normal ACC operation.
Note: When braking is applied by the ACC, the
vehicle brake lamps will be switched on
although the brake pedal will not move.
CAUTION
RESUME should only be used if the
driver is aware of the set speed and
intends to return to it.