182Driving and operatingAdaptive cruise control automatically
decelerates the vehicle when
approaching a slower moving vehicle. It then adjusts the vehicle speed to
follow the vehicle ahead at the
selected following distance. The
vehicle speed increases or decreases
to follow the vehicle in front, but will
not exceed the set speed. It may
apply limited braking with activated
brake lights.
The adaptive cruise control can store set speed over 30 km/h for manual
transmission. On vehicles with
automatic transmissions the system
can brake until a full stop and drive off
from a stop.
Adaptive cruise control uses radar
and camera sensors to detect the
vehicles ahead. If no vehicle is
detected in the driving path, the
adaptive cruise control will behave
like a conventional cruise control.
Adaptive cruise control is mainly
advised to be used on long straight
roads like highways or country roads
with steady traffic. Do not use the
system if it is not advisable to
maintain a constant speed.
Control indicator A 3 103, C 3 103.9 Warning
The complete driver attention is
always required while driving with
adaptive cruise control. The driver stays fully in control of the vehicle
because the brake pedal, the
accelerator pedal and the cancel
switch have priority over any
adaptive cruise control operation.
Switching on
Illustrations show different versions.
Driving and operating183Press C to switch on adaptive cruise
control. C appears in the Driver
Information Centre.
Activation by setting the speed
Adaptive cruise control can be
activated at speeds above 25 km/h on
vehicles with automatic transmission
or 30 km/h on vehicles with manual
transmission. The upper speed limit is 180 km/h.
Accelerate to the desired speed and
turn thumb wheel to SET/-, the
current speed is stored and
maintained.
The adaptive cruise control symbol
C , the following distance setting and
set speed are indicated in the Driver
Information Centre.
The accelerator pedal can be
released. Adaptive cruise control
remains activated while gear shifting.
Overriding set speed
It is always possible to drive faster
than the selected set speed by
depressing the accelerator pedal.
When the accelerator pedal is
released, the vehicle returns to the
desired distance if a slower vehicle is
ahead. Otherwise it returns to the
stored speed.
Once the system is activated,
adaptive cruise control decelerates or
brakes if it detects a vehicle ahead,
which is slower or closer than the
desired following distance.9 Warning
Accelerating by the driver
deactivates automatic braking by
the system. This is indicated as a
pop-up warning in the Driver
Information Centre.
Increase speed
With adaptive cruise control active,
hold thumb wheel turned to RES/+:
speed increases continuously in large
increments, or repeatedly activate
RES/+: speed increases in small
increments.
The current speed can be stored and maintained by pressing the
accelerator pedal and simultaneously turning the thumb wheel to SET/-.
Reduce speed With adaptive cruise control active,
hold thumb wheel turned to SET/-:
speed decreases continuously in
large increments, or repeatedly
activate SET/-: speed decreases in
small increments.
The current speed can be stored and
maintained by pressing the
accelerator pedal and simultaneously turning the thumb wheel to SET/-.
Resume stored speed
If the system is switched on but
inactive, then turn thumb wheel to
RES/+ at a speed above 25 km/h to
resume the stored speed.
184Driving and operatingFull speed range adaptive cruise
control on vehicles with automatic
transmission
Full speed range adaptive cruise
control will maintain a following
distance behind a detected vehicle
and slow your vehicle to a stop behind
that vehicle.
In case of a brief stop of the vehicle
ahead the adaptive cruise control will drive off automatically without driver
action. If necessary, press RES/+ or the accelerator pedal to resume
adaptive cruise control.
If the stopped vehicle ahead was
stopped for a longer time and then
begins to move forward, the green
illuminated vehicle ahead control
indicator A will flash and a warning
chime will sound as a reminder to
check traffic before resuming.
When the vehicle ahead drives away,
press RES+ or the accelerator pedal
to resume adaptive cruise control. If
stopped for more than five minutes or
if the driver's door is opened and the
driver's seat belt is unbuckled, the electric parking brake is appliedautomatically to hold the vehicle.Control indicator m will illuminate. To
release electric parking brake, press
the accelerator pedal. Electric parking
brake 3 1719 Warning
When full speed range adaptive
cruise control is deactivated or
cancelled, the vehicle will no
longer be held at a stop and can
start to move. Always be prepared to manually apply the brake to hold the vehicle stationary.
Do not leave the vehicle while it is being held at a stop by the full
speed range adaptive cruise
control. Always move selector
lever to park position P and switch
off the ignition before leaving the
vehicle.
Setting the following distance
When adaptive cruise control detects
a slower moving vehicle in the driving path, it will adjust the vehicle speed tomaintain the following distance
selected by the driver.
The following distance can be set to
near, medium or far.
Press E, the current setting is shown
in the Driver Information Centre.
Press E again to change the
following distance. The setting is also displayed in the Driver Information
Centre.
Driving and operating185
The selected following distance is
indicated by filled distance bars in the
adaptive cruise control page.
Note that the following distance
setting is shared with the sensitivity
setting of forward collision alert
3 189.
Example: If setting 3 (far) is selected,
then the driver is warned sooner
before a possible collision, also if
adaptive cruise control is inactive or
switched off.
9 Warning
The driver accepts full
responsibility for the appropriate
following distance based on traffic, weather and visibility conditions.
Following distance must be
adjusted or the system switched
off when required by the prevailing
conditions.
Adaptive cruise control in Sport
mode
On vehicles with Flex Ride driving
modes, the driver can slightly
increase the Adaptive cruise control
acceleration when Sport mode is
selected.
Detecting the vehicle ahead
The green illuminated vehicle ahead
control indicator A is displayed when
the system detects a vehicle in the driving path. The range of the sensors
is between 25 and 150 metres
depending on vehicle speed.
Forward collision alert 3 189.
If this symbol does not display, or
displays briefly, adaptive cruise
control will not respond to vehicles ahead.
186Driving and operatingDeactivation
Adaptive cruise control is deactivated by the driver when:
● y is pressed.
● Brake pedal is applied.
● Clutch pedal is depressed for more than four seconds.
● Selector lever of automatic transmission is moved to N.
The system is also automatically
deactivated when:
● Vehicle speed accelerates above
190 km/h or slows down below
25 km/h, on vehicles with
automatic transmission it slows
down to a stop without
deactivating within five minutes.
● The Traction Control system is deactivated or operating.
● The Electronic Stability Control is
deactivated or operating.
● There is no traffic and nothing detected on the road sides for
approx. one minute. In this case there are no radar echoes and
the sensor may report that it is
blocked.● The active emergency braking system is applying the brakes.
● Driving on steep inclines.
● The radar sensor is blocked by an ice or water film.
● A fault is detected in the radar, camera, engine or brake system.
● The brakes are too hot.
Additionally, the system is
automatically deactivated on vehicles with automatic transmission (full
speed range adaptive cruise control)
when:
● The electric parking brake is applied.
● The vehicle is being held to a stop
by the system for more than
five minutes.
● The vehicle stops, the driver's seat belt is unbuckled and the
driver's door is opened.
When adaptive cruise control is
deactivated, the control indicator m
changes from green to white and a
pop-up message is displayed in the
Driver Information Centre.
The stored speed is maintained.
On Midlevel display, the stored speed is indicated in brackets in the Driver
Information Centre when the system
is deactivated but not switched off.
On Uplevel display, the adaptive
cruise control symbol C changes
from green to white when the system
is deactivated but not switched off.
9 Warning
When adaptive cruise control is
deactivated, the driver must take
over full brake and engine control
immediately.
Switching off
Press C to switch off adaptive cruise
control. C in the Driver Information
Centre extinguishes. The stored
speed is deleted.
Driving and operating187Switching off the ignition also
switches off adaptive cruise control
and deletes the stored speed.
Driver's attention ● Use adaptive cruise control carefully on bends or mountainroads, as it can lose the vehicle
ahead and needs time to detect it again.
● Do not use the system on slippery roads as it can create
rapid changes in tyre traction
(wheel spinning), so that you
could lose control of the vehicle.
● Do not use adaptive cruise control during rain, snow or
heavy dirt, as the radar sensor
can be covered by a water film,
dust, ice or snow. This reduces or
suppresses completely the
visibility. In case of sensor
blockage, clean the sensor
cover.System limits9 Warning
The system's automatic brake
force does not permit hard braking and the braking level may not be
sufficient to avoid a collision.
● After a sudden lane change, the system needs a certain time to
detect the next preceding
vehicle. So if a new vehicle is
detected, the system may
accelerate instead of braking.
● Adaptive cruise control does ignore the oncoming traffic.
● Adaptive cruise control does not consider pedestrians and
animals for braking and driving
off.
● Adaptive cruise control considers
stopped vehicles only at low
speed.
● Do not use adaptive cruise control when towing a trailer.
● Do not use adaptive cruise control on roads with an incline ofmore than 10%.
Bends
The adaptive cruise control calculates
a predicted path based on the
centrifugal force. This predicted path
considers the current bend
characteristic, but cannot consider a
future bend change. The system may lose the current vehicle ahead or
consider a vehicle which is not in the
actual lane. This can happen when
entering or exiting a bend or if the
bend gets stronger or weaker. If it no
longer detects any vehicle ahead,
then control indicator A will
extinguish.
188Driving and operatingIf the centrifugal force is too high in a
bend, the system slows down the vehicle slightly. This braking level is
not designed to avoid spinning-off the
bend. The driver is responsible for
reducing the selected speed before
entering a bend and in general to
adapt the speed to the road type and
to existing speed limits.
Motorways
On motorways, adapt the set speed
to the situation and the weather.
Always consider that adaptive cruise
control has a limited visibility range, a
limited braking level and a certain
reaction time to verify if a vehicle is on
the driving path or not. Adaptive
cruise control may not be able to
brake the vehicle in time to avoid a
collision with a much slower vehicle or after a lane change. This is
particularly true while driving fast or ifthe visibility is reduced due to weather
conditions.
While entering or exiting a motorway,
adaptive cruise control may lose the
vehicle ahead and accelerate up to
the set speed. For this reason,
decrease the set speed before the
exit or before the entry.
Vehicle path changes
If another vehicle enters your driving
path, adaptive cruise control will first
consider the vehicle when it is
completely in your path. Be ready to
take action and depress the brake
pedal, if you need to brake more
quickly.
Hill and trailer considerations9 Warning
Do not use adaptive cruise control
on steep hill roads.
System performance on hills depends
on vehicle speed, vehicle load, traffic
conditions and the road gradient. It
may not detect a vehicle in your path
while driving on hills. On steep hills,
you may have to use the accelerator
pedal to maintain your vehicle speed.
When going downhill you may have to
brake to maintain or reduce your
speed.
Note that applying the brake
deactivates the system.
Driving and operating189Radar unit
The radar unit is mounted behind the
radiator grille behind or below the
brand emblem.
9 Warning
The radar unit was aligned
carefully during manufacture.
Therefore, after a frontal accident, do not use the system. The front
bumper may appear to be intact,
however the sensor behind can be
out of position and react
incorrectly. After an accident,
consult a workshop to verify and
correct the adaptive cruise control
sensor position.
Settings
Settings can be changed in the
vehicle personalisation menu in the
Colour-Info-Display.
Select the relevant setting in Settings,
I Vehicle in the Colour-Info-Display.
Info-Display 3 111.
Vehicle personalisation 3 117.
Fault
If the adaptive cruise control does not work due to temporary conditions
(e.g. blockage by ice, overheated
brakes or low speed manoeuvres) or
if there is a permanent system error,
then a message is displayed in the
Driver Information Centre.
Vehicle messages 3 115.
Forward collision alert The forward collision alert may help toavoid or reduce the harm caused by
front-end crashes.
If the vehicle is equipped with
conventional cruise control, the
forward collision alert uses the front
camera in the windscreen to detect a
vehicle directly ahead, in your path.
If the vehicle is equipped with
adaptive cruise control, the forward
collision alert uses the radar sensor
and front camera to detect a vehicle
directly ahead, in your path.
A vehicle ahead is indicated by the
control indicator A.
If a vehicle directly ahead is
approached too quickly, a warning
chime and alert in the Driver
Information Centre is provided.
Additionally the driver gets notified by
a flashing red LED stripe or a pop up
symbol in the head-up display which
is projected on the windscreen in the
driver's field of view.