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Adaptive cruise control (ACC)

PRINCIPLE OF OPERATION • It is the driver’s responsibility to stay alert,
Adaptive cruise control (ACC)

The Adaptive Cruise Control (ACC) system is drive safely and be in control of the vehicle
designed to assist the driver in maintaining a at all times.
gap from the vehicle ahead, or maintaining a • Keep the front of the vehicle free from dirt,
set road speed, if there is no slower vehicle metal badges or objects, including vehicle
ahead. The system is intended to assist the front protectors, which may interfere with
driver, when following other vehicles which are radar operation.
in the same lane and travelling in the same • Do not use ACC when entering or leaving a
direction. motorway.

WARNING USING ACC

ACC is not a collision warning or The system is operated by controls mounted
avoidance system. Additionally, ACC on the steering wheel. The driver can also
will not react to: intervene at any time by use of the brake or
Stationary vehicles or vehicles moving at less accelerator pedal.
than 10 km/h (6 mph).
Pedestrians or objects in the roadway. 1 2
Oncoming vehicles in the same lane.
The ACC system is based on the use of a radar,
which projects a beam directly forward of the
vehicle, to detect objects ahead.

4 3
E91495

The steering wheel controls operate as follows:

1. Speed adjust control: The thumbwheel is
E91493 used to set the speed. Rotate upwards (+) to
increase, or downwards (-) to decrease the set
The radar is mounted centrally behind the speed, until the desired speed is obtained.
bumper, above the grille, to provide a clear 2. Gap increase or decrease: Four gap settings
view forward for the radar beam. are selectable by adjusting the thumbwheel.
• Only use ACC when driving on main roads,
3 . CANCEL - Cancels but retains the set speed
with free flowing traffic.
in memory.
• Do not use in poor visibility, specifically
4 . RESUME - Resumes the set speed after it
fog, heavy rain, spray or snow.
has been cancelled.
• Do not use on icy or slippery roads.

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Adaptive cruise control (ACC)

Setting the speed Set speeds outside this range will not be
Accelerate as normal until the required speed is captured.
reached. 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
WARNING
When in follow mode, the vehicle will
E91496 not decelerate automatically to a stop,
nor will the vehicle always decelerate
Briefly rotate the speed adjust control upwards quickly enough to avoid a collision without
(+), to store the speed in the memory and and driver intervention.
engage the system. The set speed will be
displayed on the message centre: Once a set speed has been selected, the
accelerator can be released and the set road
SET SPEED speed will be maintained.

80 KM/H (50 MPH) 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
Changing the speed until the gap to the vehicle ahead corresponds
There are three ways to change the set speed: to the preset gap (Gap 3, identified by 3
• Accelerate or brake to the desired speed chevrons is the default). The vehicle is now in
then briefly rotate the speed adjust control follow mode.
upwards (+). The warning indicator in the
• Increase or decrease the speed by rotating instrument panel will be
the speed adjust control upwards (+) or illuminated.
downwards (-), until the required set
speed is shown on the message centre.
The vehicle speed will gradually change to
the selected speed.
• Increase or decrease the speed in steps of
2 km/h (1 mph), by briefly rotating the
speed adjust control upwards (+) or
downwards (-), until the desired speed is
obtained.
ACC operates between approximately 34 km/h
and 180 km/h (21 mph and 112 mph)
dependent on the country specification.

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Adaptive cruise control (ACC)

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 to the vehicle ahead can be adjusted by
rotating the gap increase/decrease control on
E91497 the steering wheel. Four gap settings are
available and the selected gap is represented
The message centre will display the gap set. by the corresponding number of chevrons in
The shortest (Gap 1), represented by 1 front of the car icon displayed on the message
chevron, and the longest (Gap 4), represented centre (Gap1 = 1 chevron, Gap 4 = 4 chevrons).
by 4 chevrons, are illustrated above. After the ignition is switched on, the default
The vehicle will then maintain the time gap to gap setting (Gap 3), will be automatically
the vehicle ahead, until: selected ready for ACC operation.
• The vehicle ahead accelerates to a speed Note: When the ignition is switched off, the
above the set speed. gap setting will revert to the default setting
• The vehicle ahead moves out of lane or out (Gap 3) when switched on again.
of view. Note: It is the driver’s responsibility to select a
• A new gap distance is set. gap appropriate to the driving conditions.
If necessary, the 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.

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Adaptive cruise control (ACC)

Overriding the speed and follow mode ACC will disengage, and clear the memory,
when:
WARNING
• The ignition is switched off
Whenever the driver overrides the • Maximum vehicle speed is reached
ACC by pressing the accelerator
• A fault occurs in the ACC system.
pedal, the ACC will not automatically
apply the brakes to maintain the gap Resuming the speed and follow mode
to any vehicle ahead.
CAUTION
The set speed and gap can be overridden by
pressing the accelerator pedal, when cruising RESUME should only be used if the
at constant speed or in follow mode. If the driver is aware of the set speed and
vehicle is in follow mode, the warning indicator intends to return to it.
will extinguish when the ACC is overridden and By pressing the RESUME button after ACC has
CRUISE OVERRIDE will be displayed in the been cancelled (e.g. after braking), the ACC will
message centre. When the accelerator is become active again, provided that the set
released, ACC will operate again and vehicle speed memory has not been erased. The set
speed will decrease to the set speed, or a lower speed will be displayed for four seconds and
speed when appropriate if follow mode is the original set speed will be resumed, unless a
active. vehicle ahead causes follow mode to become
active.
Automatic low speed switch off
If vehicle speed decreases below 30 km/h Hints on driving with ACC
(18 mph), the ACC system automatically The system acts by regulating the speed of the
switches off and the warning indicator will vehicle using engine control and the brakes.
extinguish. Gear changes may occur in response to
If the brakes were being applied by the ACC deceleration or acceleration whilst in ACC.
system, they will be slowly released. ACC is not a collision avoidance system.
This will be accompanied by an audible However, during some situations, the system
warning and DRIVER INTERVENE will be may provide the driver with an indication that
displayed in the message centre. The driver intervention is required.
must take control. An audible alarm will sound, accompanied by
the message DRIVER INTERVENE, if the ACC
Automatic switch off
detects:
ACC will disengage, but not clear the memory,
• A failure has occurred while the system is
when:
active.
• The CANCEL button is pressed.
• That using maximum ACC braking only is
• The brake pedal is pressed. not sufficient.
• Neutral, Park or Reverse gear positions are Note: ACC operates when the gear selector
selected. lever is in position S or D.
• Dynamic Stability Control activates.

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Adaptive cruise control (ACC)

Note: When engaged, the accelerator pedal ACC malfunction
rests in the raised position. Fully release the If a malfunction occurs during operation of the
pedal to allow normal ACC operation. system in cruise or follow modes, the ACC
Note: When braking is applied by the ACC, the system will switch off and cannot be used until
vehicle brake lamps will be switched on the fault is cleared. The message DRIVER
although the brake pedal will not move. INTERVENE appears briefly, and is then
replaced by the message CRUISE NOT
Detection beam issues AVAILABLE. If malfunction of the ACC, or any
related system, occurs at any other time, the
1 message CRUISE NOT AVAILABLE will be
displayed. It will not be possible to activate the
ACC system in any mode.
Accumulations of dirt, snow or ice on the radar
or cover, may inhibit ACC operation. Fitting of
2 a vehicle front protector or metallised badges,
may also affect ACC operation.
The ACC system relies on its radar to detect
objects and constantly scans ahead. If the
radar detects no objects ahead in ACC or follow
3 mode, then the ACC will be deactivated, the
audible alarm sounds and the message
DRIVER INTERVENE displays briefly. The
message ACC SENSOR BLOCKED will then be
displayed.
The same messages may also be displayed
E91498 while driving on open roads with few objects
for the radar to detect.
Detection issues can occur:
Clearing the obstruction allows the system to
1. When driving on a different line to the
return to normal operation. If the obstruction is
vehicle in front.
present when ACC is inactive, e.g. on initial
2. With vehicles that edge into your lane. starting or with the ACC system switched off,
They can only be detected once they have the message ACC SENSOR BLOCKED will be
moved fully into your lane. displayed.
3. On bends in the road. There may be issues Tyres other than those recommended may
with the detection of vehicles in front, have different sizes. This can affect the correct
when going into and coming out of a bend. operation of the ACC.
CAUTION
In these cases, ACC may brake late or
unexpectedly. The driver should stay
alert and intervene if necessary.

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Adaptive cruise control (ACC)

FORWARD ALERT FUNCTION This Forward Alert feature may be switched on
or off using the Forward Alert switch in the
lower outboard knee bolster switchpack.
When this indicator in the message
centre 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 decrease
the sensitivity of the alert.
• Press the gap increase button to display
and then increase the sensitivity of the
alert.
Both of these alerts are accompanied by the
message FORWARD ALERT in the message
centre.

E91499

Limited detection and warning of objects ahead

is provided during ACC operation by the ACC
FORWARD ALERT warning.
The enhanced Forward Alert feature
additionally provides warnings whilst ACC is
not engaged; if an object is detected close
ahead, then the warning tone and message will
be issued. The brakes will not be applied. The
Forward Alert system does not initiate any
action, the driver must take appropriate action
when the FORWARD ALERT message is
displayed. However, the system monitors
driver actions, for instance, braking, steering
or indicating and may not initiate the warning
display if the appropriate action has been taken
early enough.

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Adaptive cruise control (ACC)

Message centre information messages

Message Warning Priority Meaning

Indicator Indicator
CRUISE ENGAGED None None Displayed when cruise control system is
operating.
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 None None Cruise control or Adaptive Cruise Control
AVAILABLE malfunction.
DRIVER INTERVENE None None Action by the driver to apply the brakes is
required.
SETSPEED XXX KM/H None None Speed set for Adaptive Cruise Control.
GAP None None Set the distance (time gap).
RADAR SENSOR None None Clean the front of the vehicle in the area of
BLOCKED the radar unit (the radar is mounted
centrally behind the bumper cover above the
grille).
FORWARD ALERT OFF None None Forward alert feature has been switched off.
WARNING: A warning will not be given for
objects detected in the vehicle’s path of
travel.
FORWARD ALERT None None Forward Alert feature has been switched on
or the setting changed. A warning will be
given for objects detected in the vehicle path
of travel. A longer gap indicates that the
system will warn when detected objects are
further away than the previous setting.

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