190Driving and operating● There is no traffic and nothingdetected on the road sides forapprox. one minute. In this casethere 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.
Switching off
Press C to switch off adaptive cruise
control. C in the Driver Information
Centre extinguishes. 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
Driving and operating193consult 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 3 121.
Vehicle personalisation 3 125.
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 3 123.
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 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 which is
projected on the windscreen in the
driver's field of view.
A precondition is that forward collision
alert with front camera system is not
deactivated by pressing V on the
steering wheel or, with radar sensor,
that it is not deactivated in the vehicle
personalisation menu 3 125.
Activation
Forward collision alert with front
camera detects vehicles to distances
of approximately 60 metres and
operates automatically at all speeds
above walking speed.
Forward collision alert with radar
sensor detects vehicles to distances of approximately 150 metres and
operates automatically at all speeds
above walking speed.
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.
The control indicator A changes to
yellow when the distance to a
preceding moving vehicle gets too
small or when approaching another
vehicle too rapidly.
Driving and operating195
Note that the alert timing sensitivity
setting is shared with the following distance setting of the adaptive cruise control. So changing the alert timing
sensitivity changes the adaptive
cruise control following distance
setting.
Deactivation The system can be deactivated.
On forward collision alert with radar
sensor the system can be disabled by
the personalisation menu, 3 125.
On forward collision alert with front
camera press V repeatedly until
Forward Collision Alert Off appears in
the Driver Information Centre.
If the forward collision alert was
deactivated, alert sensitivity is set to
"medium" when ignition is switched on next time.
The last selected setting will be stored
when the ignition is switched off.
General information9 Warning
Forward collision alert is just a
warning system and does not
apply the brakes. When
approaching a vehicle ahead too
rapidly, it may not provide you
enough time to avoid a collision.
The driver accepts full
responsibility for the appropriate
following distance based on traffic, weather and visibility conditions.
The complete attention of the
driver is always required while
driving. The driver must always be
ready to take action and apply the
brakes.
System limitations
Forward collision alert is designed to warn on vehicles only, but may reactalso to other objects.
In the following cases, forward
collision alert may not detect a vehicle ahead or sensor performance is
limited:
● on winding roads
● when weather limits visibility, such as fog, rain, or snow
● when the sensor is blocked by snow, ice, slush, mud, dirt,
windscreen damage or affected
by foreign items, e.g. stickers
Following distance indication
The following distance indication
displays the distance to a preceding
moving vehicle. The front camera in
196Driving and operatingthe windscreen is used to detect the
distance of a vehicle directly ahead in
the vehicle's path. It is active at
speeds above 40 km/h.
When a preceding vehicle is detected
ahead, the distance is indicated in
seconds, displayed on a page in the
Driver Information Centre.
On Midlevel display, choose Info
Menu ? via MENU on the turn
signal lever and turn the adjuster
wheel to choose following distance
indication page, 3 115On Uplevel display, select Info menu
via steering wheel buttons and press o to select following distance
indication 3 115.
The minimum indicated distance is 0.5 seconds.
If there is no vehicle ahead or the
vehicle ahead is out of range, two
dashes will be displayed: -.- sec.
If Adaptive cruise control is active,
this page shows the alert sensitivity
setting instead of following distance
setting. 3 185.
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 3 193.
The feature uses various inputs (e.g.
camera sensor, radar sensor, brake
pressure, vehicle speed) to calculate
the probability of a frontal collision.9 Warning
This system is not intended to
replace the driver responsibility for driving the vehicle and looking
ahead. Its function is limited to
Driving and operating1993 193. If deactivated a message is
displayed in the Driver Information
Centre.
On vehicles with radar sensor the
system can be disabled in the
personalisation menu in the Info-
display, 3 125.
System limitations
In some cases, the active emergency braking system may provide an
automatic braking in situations that
seem to be unnecessary, for instance in parking garages, due to traffic signs
in a curve or due to vehicles in
another lane. This is normal
operation, the vehicle does not need
service. Firmly apply the accelerator
pedal to override the automatic
braking.Emergency automatic braking may not:
● detect a vehicle ahead on winding or hilly roads.
● detect all vehicles, especially vehicles with a trailer, tractors,
muddy vehicles, etc.
● detect a vehicle when weather limits visibility, such as in fog,rain, or snow.
To avoid malfunction keep the areas
of the camera sensor in the
windscreen and the radar sensor in
the radiator grille always clean from
dirt, dust, ice and snow.
Complete attention is always required
while driving, and you should be
ready to take action and apply the
brakes and/or steer the vehicle to
avoid crashes.
Fault
In case the system requires a service, a message is displayed in the Driver
Information Centre.If the system does not work as it
should do, vehicle messages are
displayed in the Driver Information
Centre.
Vehicle messages 3 123.
Parking assist General information
When the trailer hitch is attached,
change the configuration settings in
the vehicle personalisation menu in
the Info-Display. Vehicle
personalisation 3 125.
When attaching a trailer or bike
carrier to the trailer hitch, the parking
assist is deactivated.
Rear parking assist9 Warning
It is the driver who bears full
responsibility for the parking
manoeuvre.
Always check the surrounding
area while reversing and using the rear parking assist system.
200Driving and operatingThe rear parking assist makes
parking easier by measuring the
distance between the vehicle and
rear obstacles. It informs and warns
the driver by giving acoustic signals
and display indication.
The system has four ultrasonic
parking sensors in the rear bumper.
Activation
After ignition is switched on, the rear
parking assist is activated.
An illuminated LED in the parking
assist button r indicates that the
system is ready to operate.
Indication
The system warns the driver with acoustic signals against potentially
hazardous obstacles behind the
vehicle in a distance range up to
50 cm while a forward gear is
engaged, or up to 1.5 metres while
reverse gear is engaged.
Depending on which side of the
vehicle is closer to an obstacle, you
will hear acoustic warning signals in the vehicle on the respective side.
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
obstacles is displayed by changing
distance lines in the Driver
Information Centre 3 115.
The distance indication can be
inhibited by vehicle messages with a
higher priority. After dismissing the
message distance indication appears again.Deactivation
Press parking assist button r to
deactivate, the LED in the button
extinguishes.
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, the LED
in the button flashes for
three seconds and then extinguishes. A message is indicated in the Driver
Information Centre.
Driving and operating201Front-rear parking assist9Warning
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 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 system has four ultrasonic
parking sensors each in the rear and front bumper.
Activation
The system is activated automatically
at a speed up to 11 km/h.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 25 km/h beforehand,
parking assist will be reactivated when speed drops below 11 km/h.
When the system is deactivated, the
LED in the button extinguishes and
Park Assist Off pops-up in the Driver
Information Centre.
202Driving and operatingIndication
The system warns the driver with
acoustic signals against potentially
hazardous obstacles in front of the
vehicle in a distance range up to
80 cm and against potentially
hazardous obstacles behind the
vehicle in a distance range up to
50 cm while a forward gear is
engaged, or up to 1.5 m while reverse gear is engaged.
Depending on which side of the
vehicle is closer to an obstacle, you
will hear acoustic warning signals in the vehicle on the respective side.
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 3 115 or,
depending on the version, on the Info-
Display 3 121.
The distance indication can be
inhibited by vehicle messages with a
higher priority. After dismissing the
message distance indication appears again.
Deactivation
The system is deactivated
automatically when vehicle speed
exceeds 11 km/h.
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 3 125.
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 3 123.