Jaguar XJ (2008 year). Service manual — part 41

165

Adaptive Cruise Control (ACC)

R

Note: It is the driver’s responsibility to
select a gap appropriate to the driving
conditions.

Overriding the speed and follow mode

!

WARNING:

Whenever the driver is overriding the
ACC by depressing the accelerator
pedal, the ACC will not automatically
apply the brakes to maintain
separation from any vehicle ahead.

The set speed and gap can 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 panel 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
function will operate again and vehicle
speed will decrease to the set speed, or a
lower speed if follow mode is active.

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 panel 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, a red warning indicator and
DRIVER INTERVENE will be displayed on
the message centre. The driver must take
control.

Automatic switch off

Adaptive Cruise Control will disengage,
but not clear the memory when:
• The CANCEL button is pressed.
• The brake pedal is pressed.
• Neutral, Park or Reverse gear

positions are selected.

• Dynamic Stability Control (DSC)

activates.

Adaptive Cruise Control will disengage
and clear the memory when:
• The ignition switch is switched OFF.
• Maximum vehicle speed is reached.
• A fault occurs in the ACC system.

Resuming the set speed/follow mode

Caution: RESUME should only be used
if the driver is aware of the set speed
and intends to return to it.

By pressing the RESUME button 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 set speed will be displayed for four
seconds and the original set speed will be
resumed, unless a vehicle ahead causes
the follow mode to become active.

Hints on driving with ACC.

The system acts by regulating the speed
of the vehicle using engine control 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.

Adaptive Cruise Control (ACC)

166

L

An audible alarm will sound,
accompanied by a red warning indicator
and the message DRIVER INTERVENE if
the ACC detects:
• That a failure has occurred whilst the

system is active.

• That using maximum ACC braking

only is not sufficient.

• That the vehicle speed has decreased

below the minimum for ACC
operation.

Note:

•

Adaptive cruise control operates
when the gear selector lever is in
position 2, 3, 4, 5 or D.

•

When engaged, the accelerator pedal
rests in the raised position. Fully
release the pedal to allow normal ACC
operation.

Detection beam issues

Detection issues can occur:
• When driving on a different line to the

vehicle in front (A).

• With vehicles that edge into your lane

which can only be detected once they
have moved fully into your lane (B).

• There may be issues with the

detection of vehicles when going into
and coming out of a bend (C).

In these cases ACC may brake late or
unexpectedly. The driver should stay alert
and intervene if necessary.

167

Adaptive Cruise Control (ACC)

R

ACC malfunction

If a fault occurs during operation of the
system in cruise or follow modes, the
ACC system will switch OFF and cannot
be used until the fault is cleared.

A red warning indicator and the message
DRIVER INTERVENE appear briefly, and
are then replaced by an amber warning
indicator and the message CRUISE NOT
AVAILABLE.

If failure of the ACC or any related system
occurs at any other time, an amber
warning indicator will be displayed
accompanied by the message CRUISE
NOT AVAILABLE. It will not be possible
to activate the ACC system in any mode.

Accumulations of dirt, snow or ice on the
sensor or cover may inhibit ACC
operation. Fitting of a vehicle front
protector or metallised badges may also
affect ACC operation.

If this occurs in ACC cruise/follow mode,
the red warning indicator is displayed, the
audible alarm sounds and the message
DRIVER INTERVENE appears briefly.
These warnings are then replaced by the
amber warning indicator and the message
ACC SENSOR BLOCKED is displayed.
The system is no longer active.

Clearing the obstruction allows the
system to return to normal operation. If
the obstruction is present when ACC is
inactive, e.g. on initial starting or with the
ACC system switched off, the amber
warning indicator will be displayed with
the message ACC SENSOR BLOCKED.

Tires other than those recommended may
have different sizes. This can affect the
correct operation of the ACC.

FORWARD ALERT FUNCTION

Limited detection and warning of objects
ahead is provided during ACC operation
by the ACC DRIVER INTERVENE
warning.

The forward alert feature additionally
provides warnings whilst ACC is not
engaged; if an object is detected close
ahead then a warning tone and message
will be issued. The brakes will not be
applied.

This additional feature may be switched
on or off using the forward alert switch in
the lower outboard knee bolster
switchpack. When the indicator lamp in
the switch is on, forward alert is active.

The sensitivity of the warning may be
changed:
• Press the gap decrease button when

ACC is disengaged to display and
then decreases the sensitivity of the
alert.

• Press the gap increase button

displays and then increases the
sensitivity of the alert.

Both of these are accompanied by the
FORWARD ALERT message on the
message centre.

E86374

Automatic Speed Limiter

168

L

Automatic Speed Limiter

PRINCIPLE OF OPERATION

!

WARNING:

Automatic Speed Limiter (ASL) set
speeds must be within local speed
restriction limits. The driver must
always ensure that a safe speed is set,
taking into account the prevailing
traffic and road conditions.

ASL can be used in a situation where
varying vehicle speed is likely, but a
maximum speed must not be exceeded.

For example, where a local speed limit is
80km/h (50mph), the set speed could be
at that limit or just under. The driver is
then safe in the knowledge that the local
speed limit cannot be exceeded while
ASL is operating.

The ASL button allows the driver to select
between cruise control and the automatic
speed limiter.

The ASL can be to any speed between 30
km/h (18 mph) to 240 km/h (150 mph).

When the ASL system is selected, the
tell-tale status indicator in the switch will
illuminate. When the ASL button is
pressed again, the indicator will
extinguish, ASL will be cancelled and
cruise control will be available again.

USING THE ASL

Setting a speed limit

1. Press the ASL button. The tell tale

indicator in the switch will illuminate.

2. Press the RESUME button (1).

While a speed is being set or altered
the message centre display will show
the selected speed.

3. Use the +/- buttons (2) to set the

required speed.

4. The set speed can be adjusted at any

time by pressing the +/- buttons (2).

While a speed limit is being set or
altered, a message is displayed on the
message centre.

E86376

LIMITER SET

XXX km/h (MPH)

E86304

1

2

3