Jaguar XJ (2008 year). Service manual — part 42

169

Automatic Speed Limiter

R

Note: The message is also displayed at
other times as an information display.

When ASL is selected and a set speed
inserted, the engine will respond normally
up to the set speed. Further accelerator
pedal pressure will not increase the
vehicle speed beyond your set speed.

Suspending ASL

ASL can be suspended by pressing the
CANCEL button (3). Applying sudden,
rapid acceleration (kickdown) will also
suspend ASL.

Resuming ASL

If ASL has been suspended, it can be
reinstated with a single press of the
RESUME button (1), however, ASL will
only reinstate if the vehicle speed is less
than the current speed set in memory and
greater than 30 km/h (18 mph). The
message centre will display an
appropriate message if the vehicle speed
is too fast to resume ASL.

Exceeding the set speed

If the set speed is exceeded, e.g.on a
steep downhill section, the message
centre will display an appropriate
message along with an amber warning
indicator.

There are three categories of over limit
displays:

1. If the set speed is exceeded by up to

15 km/h (9 mph), the message centre
will display the message along with an
amber warning indicator.

2. If the set speed is exceeded by more

than 15 km/h (9 mph), the message
centre will display the message along
with a flashing amber warning
indicator.

3. If the set speed is exceeded by more

than 15 km/h (9 mph) for a duration of
five seconds, the message centre will
display the message along with a
flashing amber warning indicator and
also give an audible warning tone.

Use your brakes to rectify the situation.

ASL unavailable

If ASL is not available due to a fault, the
message centre will display an
appropriate message along with an
amber warning indicator.

When the ignition is switched off, ASL is
deactivated and any set speed is deleted
from memory.

LIMITER

CANCELLED

TOO FAST TO

RESUME LIMIT

OVER LIMIT

XXX km/h (MPH

LIMITER NOT

AVAILABLE

Stability Control

170

L

Stability Control

DYNAMIC STABILITY
CONTROL (DSC)

Unless it has been switched off, Dynamic
Stability Control is operational whenever
the engine is running. If the system is
operating, the warning indicator in the
instrument panel will flash.

The Dynamic Stability Control (DSC)
system controls the Anti-lock Braking
System (ABS), traction control and yaw
control of the vehicle.

Yaw control determines the vehicle’s
direction relative to the driver’s inputs
(sideslip and under/oversteer). It applies
braking pressure to individual wheels if
excessive variation is detected. This
ensures that the vehicle follows the
driver’s intended direction of travel.

Traction control will intervene to prevent
wheel spin, by automatically reducing the
power output from the engine and
applying braking to individual wheels.

This improves acceleration, particularly
on surfaces with uneven friction,
for example, one wheel on ice and the
other on tarmac.

ABS helps to prevent the road wheels
from locking and skidding during
emergency braking.

When the ABS system is operating,
the warning indicator in the instrument
panel will flash.

The Dynamic Stability Control system can
be switched OFF by pressing the switch
on the centre console switchpack. The
warning indicator in the instrument panel
will remain on and a message will be
shown to indicate that the system has
been switched OFF. If the switch is
pressed again the system will switch ON.

If cruise control is engaged it will
automatically disengage if stability control
activates.

A system malfunction is indicated by the
illumination of the amber DSC warning
indicator and the message DSC FAULT.

It is safe to drive the vehicle but the
system may not activate under wheel spin
or slide conditions. Report the fault to a
Jaguar Dealer as soon as possible.

!

WARNING:

• The fact that the vehicle is fitted

with Dynamic Stability Control must
never allow the driver to be
tempted into taking risks which
could affect his/her safety or that of
other road users. In all cases it
remains the driver’s responsibility
to drive safely according to the
prevailing conditions.

• It is recommended that when using

snow chains, DSC should be
switched OFF.

E86378

171

Braking System

R

Braking System

ANTI-LOCK BRAKING SYSTEM
(ABS)

This system helps to prevent the road
wheels from locking and skidding during
emergency braking, assisting the driver to
maintain full steering and directional
stability.

The factor controlling ultimate stopping
distance and cornering ability is tire/road
adhesion.

!

WARNING:

The fact that a vehicle is fitted with ABS
must never allow the driver to be
tempted into taking risks which could
affect his/her safety or that of other
road users.

!

WARNING:

The addition of ABS cannot overcome
the consequences of trying to stop in
too short a distance or cornering at too
high a speed, or the risk of
aquaplaning.

!

WARNING:

The driver should always take road
conditions into account.

A slippery road surface always
requires more braking distance for a
given speed, even with ABS.

A possible increase in stopping
distance compared to locked wheels
may occur during ABS operation on
slushy snow, gravel, sand, or some
heavily corrugated or ridged warning
sections of road surfaces.

ABS optimises tire/road adhesion under
maximum braking conditions though it
cannot provide increased cornering
ability. There is no need for special
braking techniques, such as pumping the
brakes, to achieve optimum braking
distances and control on poor or slippery
road surfaces. Tires must be in good
condition to achieve maximum adhesion.

During normal braking the ABS will not be
activated. However, if the braking force
applied begins to exceed tire/road
adhesion the ABS will automatically
activate, preventing the road wheels from
locking.

In these circumstances a pulsating effect
will be felt from the brake pedal indicating
that the system is functioning.
The pulsating effect is due to small
fluctuations in pressure supplied to the
brakes by the system to maintain full
tire/road adhesion.

Under severe braking on some road
surfaces tire noise may be apparent even
though the wheels will at no time become
locked.

ABS MONITORING

The ABS control module monitors the
ABS electrical system from ignition switch
ON to ignition switch OFF.

Any malfunction will be indicated by the
anti-lock warning indicator coming on.

Should a fault develop in the ABS system,
the brake system will still operate
conventionally and with the same
standard of performance as vehicles not
equipped with ABS.

Braking System

172

L

Hints on driving with ABS

The Anti-lock Brake System (ABS) helps
the driver to maintain full steering and
directional stability during emergency
braking by preventing the road wheels
from locking and skidding. ABS
constantly monitors the speed of each
road wheel and varies brake pressure to
each, according to the available grip. ABS
optimises the tire-to-road adhesion under
maximum braking.

When ABS is activated, you will feel a
pulsating effect on the brake pedal. This is
normal and you must maintain maximum
pressure on the brake pedal for ABS to be
effective.

ABS will enable you to steer around
obstacles during emergency braking.
ABS will not eliminate the dangers
inherent when:
• driving too close to the vehicle in front

of you

• aquaplaning
• cornering with excessive speed
• poor road surfaces.

Anti-lock Brake System (ABS) warning
indicator

!

WARNING:

If the ABS warning indicator illuminates
whilst driving, avoid heavy braking.
Seek qualified assistance as soon as
possible. Failure to follow this
instruction may lead to personal injury
or loss of vehicle control.

If a fault is detected in the ABS, the ABS
warning indicator will illuminate. Drive
with care if the ABS warning indicator
illuminates or remains on after the bulb
check cycle. The brake system will
continue to function normally, but without
ABS braking.

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 initiates the
full braking effect. This can reduce
stopping distances in critical situations,
which can help an inexperienced driver to
stop in the same distance as an
experienced driver.

!

WARNING:

The EBA system is an additional safety
system: it is not intended to relieve the
driver of his responsibility for
exercising due care and attention when
driving.