Driving and operating225Deactivation of the functionalityAdaptive 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
120 mph or slows down below
28 mph.
● The Traction Control system is operating.
● Electronic Stability Control is operating.
● There is no traffic and nothing detected on the road sides for
several minutes. 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.
● Radar sensor is blocked by an ice
or water film.
● A fault is detected in the radar, engine or brake system.
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 and
indicated in brackets in the Driver
Information Centre. 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.
Switching off the system
Press C to switch off adaptive cruise
control. The control indicator m and
C in the Driver Information Centre
extinguish. 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 mountainroads, as it can lose the vehicle
ahead and require 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 completely suppresses the
226Driving and operatingvisibility. In case of sensor
blockage, clean the sensor
cover.
System limits ● 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 brake for pedestrians, animals,very slow speed driving or
stopped vehicles.
● Don't use adaptive cruise control when towing a trailer.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.
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 in
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 if 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
228Driving and operatingconsult a workshop to verify and
correct the adaptive cruise control sensor position.
Settings
Settings can be changed in the
vehicle personalisation menu in the
Info-Display.
Select the relevant setting in
Settings in the Info-Display.
Info-Display 3 121.
Vehicle personalisation 3 123.
Fault
If the adaptive cruise control does not
work due to temporary conditions
(e.g. blockage by ice) or if there is a
permanent system error, then a
message is displayed in the Driver
Information Centre.
Vehicle messages 3 122.
Forward collision alert The forward collision alert can help to
avoid or reduce the damage caused
by front-end crashes.
A vehicle ahead is indicated by a
control indicator A.
If a vehicle directly ahead is
approached too quickly, a warning
chime and alert in the Driver
Information Centre is provided.
A precondition is that forward collision
alert is activated in the vehicle
personalisation menu 3 123 or that it
is not deactivated by pressing V
(depending on the system, see
following).
Depending on the vehicle's
equipment, there are two variants of
the forward collision alert available:
● Forward collision alert based on
radar system
on vehicles equipped with
adaptive cruise control 3 221.
● Forward collision alert based on
front camera system
on vehicles with traditional cruise
control 3 218.
Forward collision alert based on
radar system
The system uses the radar sensor
behind the radiator grille to detect a
vehicle directly ahead, in your path,
within a distance of max. 150 metres.
Activation
Forward collision alert operates
automatically above walking speed, provided that Auto collision
preparation setting is not deactivated
in the vehicle personalisation menu
3 123.
230Driving and operatingSettings
Settings can be changed in the
vehicle personalisation menu in the
Info-Display.
Select the relevant setting in
Settings in the Info-Display.
Vehicle personalisation 3 123.
Forward collision alert based on
front camera system
Forward collision alert uses the front
camera system in the windscreen to
detect a vehicle directly ahead, in
your path, within a distance of approx.
60 metres.
Activation
Forward collision alert operates
automatically above 25 mph, if it is not deactivated by pressing V, see
below.
Selecting the alert sensitivity
The alert sensitivity can be set to
near, medium or far.
Press V; the current setting is shown
in the Driver Information Centre.
Press V again to change the alert
sensitivity.
Alerting the driver
The vehicle ahead control indicator
A illuminates green in the instrument
cluster when the system has detected
a vehicle in the driving path.Caution
The colour lighting of this control
indicator does not correspond to
local traffic laws on following
distance. The driver bears full
responsibility for maintaining safe
following distance according to
applicable traffic rules, weather
and road conditions etc. at all
times.
When the distance to a preceding
moving vehicle gets too small or when
approaching another vehicle too rapidly and a collision is imminent the collision alert symbol pops-up in the
232Driving and operatingIf there is no vehicle ahead or the
vehicle ahead is out of range, two
dashes will be displayed: -.- s.
If Adaptive cruise control is active,
this page shows the alert sensitivity
setting instead of following distance setting. 3 221.
Active Emergency Braking
Active emergency braking can help to reduce the damage and injury from
crashes with vehicles and obstacles
directly ahead, when a collision can no longer be avoided either by
manual braking or by steering. Before
the active emergency braking
applies, the driver is warned by the forward collision alert 3 228.
The feature uses various inputs (e.g.
radar sensor, brake pressure, vehicle speed) to calculate the probability of
a frontal collision.
Active emergency braking operates automatically above walking speed,
provided that Auto collision
preparation setting is not deactivated
in the vehicle personalisation menu
3 123.
The system includes: ● brake preparation system
● emergency automatic braking
● forward looking brake assist9Warning
This system is not intended to
replace the driver responsibility of driving the vehicle and looking
ahead. Its function is limited to
supplemental use only. The driver shall continue to apply the brake
pedal as the driving situation
dictates.
Brake preparation system
When approaching a vehicle ahead
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.
The brake system is prepared so that braking can occur more rapidly.
Emergency automatic braking
After the brake preparation and just
before the imminent collision, this
function automatically applies limited
braking to reduce the impact speed of the collision.
Forward looking brake assist
In addition to brake preparation
system and emergency automatic
braking, the forward looking brake
assist function makes the brake assist more sensitive. In this way,
depressing the brake pedal slightly
results immediately in a strong
braking. This function helps the driver
brake quicker and stronger before the imminent collision.
Driving and operating2339Warning
Active emergency braking is not
designed to apply strong
autonomous braking or to avoid automatically a collision. It is
designed to reduce the vehicle
speed before collision. It may not
react on stopped vehicles,
pedestrians or animals. After a
sudden lane change, the system
needs a certain time to detect the
next preceding vehicle.
The complete attention of the
driver is always required while
driving. The driver shall always be ready to take action and apply the brakes and steer to avoid
collisions. The system is designed
to work with all occupants wearing their seat belts.
System limitations
The active emergency braking has
limited or no function during rain,
snow or heavy dirt, as the radar
sensor can be covered by a water
film, dust, ice or snow. In case of
sensor blockage, clean the sensor
cover.
In some seldom cases the active
emergency braking system may
provide a short automatic braking in
situations that seem to be
unnecessary, for instance due to
traffic signs in a curve or due to
vehicles in another lane. This is
acceptable operation, the vehicle
does not need service. Firmly apply
the accelerator pedal to override the
automatic braking.
Settings
Settings can be changed in the
vehicle personalisation menu in the
Info-Display.
Select the relevant setting in
Settings in the Info-Display.
Vehicle personalisation 3 123.
Fault
In the event of a system service
requirement, a message is displayed
in the Driver Information Centre.If the system does not work as it
should, vehicle messages are
displayed in the Driver Information
Centre.
Vehicle messages 3 122.
Parking assist
Front-rear parking assist9 Warning
The driver bears full responsibility
for the parking manoeuvre.
Always check the surrounding
area when driving backwards or
forwards while using parking
assist system.
The front-rear parking assist
measures the distance between the vehicle and obstacles in front of and
behind the vehicle. It informs and
warns the driver by giving acoustic
signals and display indication.
It uses two different acoustic warning
signals for the front and rear
monitoring areas, each with a
different tone frequency. The signal
234Driving and operatingfor front obstacles sounds via the
front speakers, for rear obstacles it
sounds via the rear speakers.
The system has four ultrasonic
parking sensors each in the rear and
front bumper.
Activation
When reverse gear is engaged, the
front and rear parking assist is ready
to operate.
The system is also activated
automatically at a speed up to
7 mph.
An illuminated LED in the parking
assist button r indicates that the
system is ready to operate.
If r is switched off within an ignition
cycle, the front parking assist is
deactivated. If vehicle speed has exceeded 15 mph beforehand,
parking assist will be reactivated when speed drops below 7 mph.
Indication
The system warns the driver with
acoustic signals against potentially
hazardous obstacles behind and in
front of the vehicle.
Depending on which side of the
vehicle is closer to an obstacle, you
will hear acoustic warning signals on
the respective side of the vehicle. The
interval between the sounds
becomes shorter as the vehicle gets
closer to that obstacle. When the
distance is less than approx. 30 cm,
the sound is continuous.
Additionally, the distance to rear and
front obstacles is displayed by
changing distance lines in the Driver
Information Centre 3 116 or,
depending on the version, on the Info- Display 3 121.
Driving and operating235Rear obstacles are indicated
acoustically and visually at the same time.
Front obstacles are indicated visually
first. At distances less than 80 cm an
acoustic signal also sounds.
The distance indication can be
inhibited by vehicle messages with a higher priority. After dismissing themessage distance indication appears
again.
Deactivation
The rear parking assist automatically
switches off when reverse gear is
disengaged.
The front parking assist is deactivated
automatically at a speed above
7 mph.
Manual deactivation is also possible by pressing the parking assist button
r .
When the system is deactivated
manually, the LED in the button
extinguishes and Park Assist Off
pops-up in the Driver Information
Centre.
After a manual deactivation, the front- rear parking assist is activated again
if r is pressed or if reverse gear is
engaged.
The complete system can be
manually deactivated in the vehicle
personalisation menu in the
Info-Display. It remains deactivated
during the ignition cycle or until
activation in personalisation menu
again. Vehicle personalisation 3 123.
When using the trailer hitch change
the configuration settings in the
vehicle personalisation menu in the
Info-Display. Vehicle personalisation
3 123.
Fault
In the event of a fault or if the system
does not work temporarily, e.g.
because of high external noise level
or other interference factors, a
message pops-up in the Driver
Information Centre.
Vehicle messages 3 122.
Basic notes on parking assist
systems9 Warning
Under certain circumstances,
various reflective surfaces on
objects or clothing as well as