180Driving and operatingRelease the accelerator pedal and
the speed limiter function is
reactivated once a speed lower than the limit speed is obtained.
Deactivation of the functionality
Press y: speed limiter is deactivated
and the vehicle can be driven without
speed limit.
On Baselevel display the stored
limited speed is indicated in brackets.
On Mid- or Uplevel display L
changes to white.
Additionally, a corresponding
message appears.
Speed limiter is deactivated, but not
switched off. Last stored speed
remains in memory for later speed
resume.
Resume limit speed
Turn thumb wheel to RES/+. The
stored speed limit will be obtained
and is indicated without brackets in
the Driver Information Centre.
Switching off the system
Press L, the speed limit indication
extinguishes in the Driver Information Centre. The stored speed is deleted.
By pressing m to activate cruise
control or adaptive cruise control,
speed limiter is also deactivated and
the stored speed is deleted.
By switching off the ignition, speed
limiter is also deactivated, but the
speed limit will be stored for next
speed limiter activation.
Adaptive cruise control
Adaptive cruise control is an
enhancement to conventional cruise
control with the additional feature of maintaining a certain distance behind the vehicle ahead.Adaptive 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.
To facilitate overtaking a vehicle on
the motorway, the activation of the
turn lights reduces the following
distance for a short time. This function is implemented only on the respective
driver's side depending on left or right
hand drive vehicle configuration.
The adaptive cruise control can store
set speed over 19 mph. On vehicles
with automatic transmissions the
system can brake until a full stop and drive off from a stop.
Driving and operating183Full speed range adaptive cruise
control on vehicles with automatic transmission
Full speed range adaptive cruisecontrol will maintain a following
distance behind a detected vehicle
and slow your vehicle to a stop behind
that vehicle.
When the vehicle ahead accelerates
after a brief stop, the adaptive cruise
control will drive off automatically
without driver action. If necessary,
press RES/+ or the accelerator pedal
to resume adaptive cruise control.
Pressing the accelerator pedal allows more control over the acceleration
after driving off. Note that automatic
braking is disabled during usage of
the accelerator pedal.
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 proceeding.9 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 moving. Always be prepared
to manually apply the brake pedal
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 drivingpath, it will adjust the vehicle speed to
maintain the following distance
selected by the driver.
The following distance can be set to
near, medium or far.
Press K, the current setting is shown
in the Driver Information Centre.
Press K again to change the
following distance. The setting is also
displayed in the Driver Information
Centre.
Driving and operating185Detecting 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 m 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.
Indication on Driver Assistance page
If the system is active and a preceding vehicle is detected, the bars in front of the vehicle symbol appear green and
indicate set gap position.
Deactivation of the functionality
Adaptive cruise control is deactivated by the driver when:
● y is pressed.
● Brake pedal is applied.
● Clutch pedal is depressed for more than 4 seconds.
● Selector lever of automatic transmission is moved to N.
The system is also automatically
deactivated when:
● Vehicle speed accelerates above
120 mph or slows down below
15 mph. Vehicles with automatic
transmission slows down to a
stop without deactivating within
5 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 forapprox. 1 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 need to cool down.
186Driving and operatingAdditionally, the system is
automatically deactivated on vehicles
with automatic transmission (full
speed range adaptive cruise control)
when:
● The incline uphill or downhill is greater than 20%.
● The electric parking brake is applied.
● The vehicle is being held to a stop
by the system for more than
5 minutes.
● The vehicle stops, the driver's seat belt is unbuckled and thedriver's door is opened.
When adaptive cruise control is
deactivated, the control indicator C
changes from green to white and a
pop-up message is displayed in the
Driver Information Centre.
The stored speed is maintained.The stored speed is indicated in
brackets in the Driver Information
Centre when the system is
deactivated but not switched off.
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 the system
Press v to switch off adaptive cruise
control. The control indicator C
extinguishes in the Driver Information Centre. The stored speed is deleted.
Switching 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 mountain
roads, 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.
Driving and operating187System limits9Warning
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. The
camera applies a certain correction
based on the detectable lane
markings. The control indicator A will
extinguish, if a vehicle ahead is no longer detected.
If 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. Furthermore,
adaptive cruise control was designed to brake as late as possible to allow
changing the lane before the
automatic braking. Adaptive cruise
control may not be able to brake the
vehicle in time to avoid a collision with
188Driving and operatinga much slower vehicle or after a lane
change. This is particularly true while
driving fast or if the 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 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. Full speed range
adaptive control is deactivated
automatically, as the vehicle is
stopping uphill on an incline greater than 10%. In this condition, be
prepared to take control of the
vehicle.
Note that applying the brake
deactivates the system.
Radar unit
The radar unit is mounted behind the
radiator grille or below the brand
emblem.
9 Warning
The radar unit was aligned
carefully during manufacture.
Therefore, in the event of a front-
end impact, 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
194Driving and operatingIf equipped only with front camera the
active emergency braking operates in forward gear above walking speed up
to 50 mph.
If equipped with radar sensor, active
emergency braking operates in
forward gear at all speeds above
walking speed. Only front pedestrian
protection is active up to 50 mph.
Activation
A precondition is that Forward
Collision System and Front
pedestrian detection are not
deactivated in the vehicle
personalisation menu 3 122.
Brake preparation system
When approaching a vehicle ahead
or a pedestrian so quickly that a
collision is likely, the brake
preparation system slightly
pressurises the brakes. This reduces
the response time, when a manual or
automatic braking is requested.Emergency automatic braking
After activation of brake preparation
system and just before the imminent
collision, this function automatically
applies limited braking to reduce the
impact speed of the collision or
prohibit a crash.
If active emergency braking is
applied, a message appears in the Driver Information Center and a
chime sounds.
Depending on the situation, the
vehicle may automatically brake
moderately or hard. This front
automatic braking can only occur if a
vehicle ahead is detected, indicated by the vehicle ahead indicator A
3 189. On vehicles with front
pedestrian protection, front automatic braking can also occur when a
pedestrian ahead is detected.
Below a speed of 25 mph the system
can apply full braking.
Emergency automatic braking may
slow the vehicle to a complete stop to
try to avoid a potential crash. If this
happens, emergency automatic
braking may engage the electricparking brake to hold the vehicle at a
stop. To release press the electric
parking brake button or firmly press
the accelerator pedal.9 Warning
Emergency automatic braking is
an emergency crash preparation
feature and is not designed to
avoid crashes. Do not rely on the
system to brake the vehicle.
Emergency automatic braking will
not brake outside of its operating speed range and only responds to
detected vehicles and
pedestrians.
Forward looking brake assist
In addition to the brake preparation
system and emergency automatic
braking, the forward looking brake
assist function makes the brake assist more sensitive. Therefore, pressing
the brake pedal less strongly results
in immediate hard braking. This
function helps the driver brake
quicker and harder before the
imminent collision.
Driving and operating197Front pedestrian protection includes:● detecting front pedestrian ahead
● front pedestrian alert
● automatic braking
Detecting front pedestrian ahead
A pedestrian ahead up to a distance
of approx. 40 m is indicated by the
control indicator 7 in the instrument
cluster. On vehicles with head-up
display, 7 is projected on the
windscreen.
Front pedestrian alert
When approaching a detected
pedestrian too quickly, the collision
alert symbol pops up in the Driver Information Centre and the pop-upsymbol 7 in the head-up display is
projected on the windscreen in the
driver's field of view. A warning chime is provided. The brake system may
prepare for driver braking to occur
more rapidly which can cause a brief, mild deceleration. Continue to apply
the brake pedal as required.
Cruise control or Adaptive cruise
control may be disengaged when the
Front pedestrian alert occurs.
Automatic braking If a crash into a pedestrian directly
ahead is imminent, and the brakes
have not been applied, Automatic
braking may automatically brake
moderately or brake hard. This can
help to avoid some very low speed
pedestrian crashes or reduce
pedestrian injury.
Automatic braking levels may be
reduced under certain conditions,
such as higher speeds.If this happens, automatic braking
may engage the Electric parking
brake to hold the vehicle at a stop.
Release the parking brake. Pressing
the accelerator pedal will also release Automatic braking and Electric
parking brake 3 170.
This system includes Intelligent brake
assist, and the Emergency automatic braking system may also respond to
pedestrians.
Active emergency braking 3 193.
Automatic braking can be disabled in
the vehicle personalisation menu
3 122.
General information9 Warning
The driver must always be ready
to take action and apply the brakes and steer to avoid collisions.