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Driving and operating191
Vehicle messages 3 119.
Forward collision alert The forward collision alert can help to
avoid or reduce the harm caused by
front-end impacts.
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 3 120 or that it
is not deactivated by pressing V
(depending on the system, see
below).
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 3 183.
● Forward collision alert based on
front camera system
on vehicles with no cruise control or traditional cruise control only
3 180.
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
3 120.
Selecting the alert sensitivity
The alert sensitivity can be set to
near, medium or far.
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192Driving and operating
Press E, the current setting is shown
in the Driver Information Centre.
Press E again to change the alert
sensitivity. The setting is also displayed in the Driver Information
Centre.Note that the alert timing sensitivity
setting is shared with the following
distance setting of the adaptive cruise control 3 183. So changing the alert
timing sensitivity changes the
adaptive cruise control following
distance setting.
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
short or when approaching another
vehicle too rapidly.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.
If a collision is imminent, the collision
alert symbol pops-up in the Driver
Information Centre and a warning
chime sounds. Depress the brake
pedal if it is required by the situation.
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Driving and operating193SettingsSettings 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.
Colour-Info-Display 3 117.
Vehicle personalisation 3 120.
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.
When the distance to a preceding
moving vehicle gets too short or when approaching another vehicle too
rapidly and a collision is imminent, the
collision alert symbol pops-up in the
Driver Information Centre.
Simultaneously, a warning chime sounds. Depress the brake pedal, if it
is required by the situation.
Deactivation
The system can be deactivated.
Press V repeatedly until Forward
Collision Alert Off appears in the
Driver Information Centre.
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194Driving and operatingGeneral information for both
variants of forward collision alert9 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 for vehicles only, but may also
react to other objects.
In the following cases, forward
collision alert may not detect a vehicle ahead or sensor performance may be 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 system uses,
depending on the vehicle equipment,
either the radar behind the radiator
grille or the front camera in the
windscreen to detect the distance of
a vehicle directly ahead in your lane.
It is active at speeds above 25 mph.
When a preceding vehicle is detected
ahead, the distance is indicated in
seconds, displayed on a page in the
Driver Information Centre 3 110.On Baselevel display set Settings
X with the Menu button and select
Following distance indication via the
adjuster wheel on the turn signal lever
3 110.
On Midlevel or Uplevel display, select
Info menu and press o to select
Following distance indication 3 110.
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: -.- s.
If Adaptive cruise control is active,
this page shows the following
distance setting instead 3 183.
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Driving and operating195Active emergency braking
Active emergency braking can help to reduce the damage 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 3 191.
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
3 120.
The system includes: ● brake preparation system
● emergency automatic braking
● forward looking brake assist9Warning
This system is not intended to
replace the driver responsibility for driving the vehicle and looking
ahead. Its function is limited to
supplemental use only. The driver must 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.
Below a speed of 11 mph the system
can apply full braking.
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,
depressing the brake pedal less
strongly results in immediate hard
braking. This function helps the driver
brake quicker and harder before the
imminent collision.9 Warning
Active emergency braking is not
designed to apply hard
autonomous braking or to
automatically avoid a collision. It is designed to reduce the vehicle
speed before a collision. It may not
react for stopped vehicles,
pedestrians or animals. After a
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196Driving and operatingsudden 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 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.
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.
Colour-Info-Display 3 117.
Vehicle personalisation 3 120.
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 do, vehicle messages are
displayed in the Driver Information
Centre.
Vehicle messages 3 119.
Parking assist
9 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.
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Driving and operating197Front-rear parking assist
The front-rear parking assist
measures the distance between the vehicle and obstacles in front and
behind the vehicle. The system gives acoustic signals and display
messages.
The system has four ultrasonic
parking sensors each in the rear and front bumper.
It uses two different acoustic warning
signals for the front and rear
monitoring areas, each with a
different tone frequency. The signal
for front obstacles sounds via the
front speakers, for rear obstacles it
sounds from the rear of the vehicle.
Activation
When reverse gear is engaged, the
front and rear parking assist is ready
to operate.
The front parking assist 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 the vehicle exceeds a speed of
7 mph, the front parking assist is
deactivated. The front parking assist
is always reactivated when vehicle
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 obstacles is shown in the Driver Information
Centre 3 110.
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198Driving and operating
The distance to a front and rear
obstacle is indicated by changing
distance lines around the vehicle.
Rear 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 in the Driver
Information Centre can be inhibited
by vehicle messages with a higher
priority. After approving the message
by pressing SET/CLR on the turn
signal lever or 9 on right steering
wheel control, 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 possible by
pressing the parking assist button
r briefly.
When the system is deactivated, the
LED in the button extinguishes.
Additionally, Park Assist Off pops-up
in the Driver Information Centre when the system is deactivated manually.
After a manual deactivation, the front
parking assist is activated again if the
parking assist button r is pressed
or if reverse gear is engaged.
Fault
In the event of a fault in the system or if the system does not work due to
temporary conditions, e.g. ice
covered sensors, a message is
displayed in the Driver Information
Centre.
Vehicle messages 3 119.
Advanced parking assist9 Warning
The driver bears full responsibility
for accepting the parking slot
suggested by the system and the
parking manoeuvre.
Always check the surrounding
area in all directions when using
advanced parking assist.