Page 201 of 323

Driving and operating199If 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.
A precondition is that forward collision
alert in the vehicle personalisation
menu is not deactivated 3 126.
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. On
vehicles with head-up display, A is
projected on the windscreen.
The control indicator A changes to
yellow when the distance to a
preceding moving vehicle gets too
small.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 time to a potential collision
with a vehicle in front gets too small
and a collision is imminent, the
collision alert symbol pops-up in the
Driver Information Centre and the
driver gets notified by a flashing red
LED stripe or the pop-up symbol in
the head-up display which is
projected on the windscreen in the
driver's field of view.
Page 202 of 323

200Driving and operating
Simultaneously a warning chime
sounds. Depress the brake pedal and
steer the vehicle, if it is required by the
situation.
Selecting the alert sensitivity Press K to set the alert sensitivity to
near, medium or far.The first button press shows the
current setting on the Driver
Information Centre. Additional button
presses will change this setting. The
chosen setting will remain until it is
changed. The alert timing will vary based on vehicle speed. The faster
the vehicle speed, the farther away
the alert will occur. Consider traffic
and weather conditions when
selecting the alert timing.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 in the
personalisation menu, 3 126.
If the forward collision alert was
deactivated, alert sensitivity is set to
"medium" when ignition is switched on next time.
Page 203 of 323

Driving and operating201The 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:
● Driving on winding or hilly roads.● During nighttime driving.
● Weather limits visibility, such as fog, rain, or snow
● The sensor in the windscreen 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
the 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 inseconds, displayed on a page in the
Driver Information Centre.On Baselevel display, choose Info
Menu ? via MENU on the turn
signal lever and turn the adjuster
wheel to choose following distance
indication page, 3 113
On Mid- and Uplevel display, select
Info menu via steering wheel buttons
and press å to select following
distance indication 3 113.
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.
Page 204 of 323

202Driving and operating
If Adaptive cruise control is active,
this page shows the alert sensitivity
setting instead of following distance setting. 3 190.
System limitations In the following cases, following
distance indication sensor
performance is limited:
● Driving on winding or hilly roads.● During nighttime driving.
● Weather limits visibility, such as fog, rain, or snow.
● The sensor is blocked by snow, ice, slush, mud, dirt, windscreen
damage or affected by foreign
items, e.g. stickers.
Active emergency braking Active emergency braking can help toreduce the damage and injury from
crashes with vehicles, pedestrians 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 3 198 or the Front pedestrian
protection alert 3 205.
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
supplemental use only to reduce
the vehicle speed before a
collision.
The system may not react to
animals. After a sudden lane
change, the system needs a
certain time to detect the next
preceding vehicle.
The driver must always be ready
to take action and apply the brakes and steer to avoid collisions.
Functionality
If equipped only with front camera the
active emergency braking operates in forward gear above walking speed up
to 85 km/h.
With radar sensor active emergency
braking operates in forward gear
above walking speed at all speeds.
Page 205 of 323

Driving and operating203A precondition is that forward collision
alert with front camera system is not
deactivated in the vehicle
personalisation menu 3 126.
The system includes: ● brake preparation system
● emergency automatic braking
● forward looking brake assist
● intelligent brake assist (only with radar sensor)
● front pedestrian protection system
Brake preparation system When approaching a vehicle ahead
or a pedestrian so quickly that a
collision is likely, the brake
preparation system slightly
pressurizes 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.
If equipped only with front camera the system operates up to a speed of 80
km/h.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. 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 3 198 . On vehicles
with front pedestrian protection, front automatic braking can also occur
when a pedestrian ahead is detected,
indicated by the pedestrian ahead
indicator 7.
If equipped only with front camera the
system operates up to a speed of 80
km/h.
Below a speed of 40 km/h 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.
Page 206 of 323

204Driving and operatingIf equipped only with front camera the
system operates up to a speed of 85
km/h.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 to 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 must 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.
Intelligent Brake Assist
If the vehicle is equipped with radar
sensor Intelligent brake assist may
activate when the brake pedal is
applied quickly by providing a boost
to braking based on the speed of
approach and distance to a vehicle
ahead.
Minor brake pedal pulsations or pedal movement during this time is normal
and the brake pedal should continue
to be applied as needed. Intelligent
brake assist will automatically
disengage only when the brake pedal is released.9 Warning
Intelligent brake assist may
increase vehicle braking in
situations when it may not be
necessary. You could block the
flow of traffic. If this occurs, take
your foot off the brake pedal and
then apply the brakes as needed.
Front pedestrian protection
3 205.
Deactivation
Active emergency braking can be
deactivated in the personalisation
menu 3 126. If deactivated a
message is displayed in the Driver
Information Centre.
System limitations In some cases, the active emergencybraking 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 if the situation and the
surroundings permit.
In the following cases, Active
emergency braking performance is limited:
● Driving on winding or hilly roads.
● Detecting all vehicles, especially vehicles with a trailer, tractors,
muddy vehicles, etc.
Page 207 of 323

Driving and operating205● Detecting a vehicle whenweather limits visibility, such as infog, rain, or snow.
● During nighttime driving.
● Weather limits visibility, such as fog, rain, or snow.
● The sensor in the windscreen is blocked by snow, ice, slush, mud,dirt, windscreen damage or
affected by foreign items, e.g.
stickers.
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 3 124.
Front pedestrian protection Front pedestrian protection may help
to avoid or reduce the harm caused
by front-end crashes with nearby
pedestrians when driving in a forward
gear.
The system uses the front camera in
the windscreen to detect a pedestrian directly ahead, in your path.
Front pedestrian protection can
detect and alert to pedestrians in a
forward gear at speeds between 8
km/h and 80 km/h. Additionally Front
pedestrian protection can provide a
boost to braking or automatically
brake the vehicle.
During daytime driving, the system
detects pedestrians up to a distance
of approximately 40 metres. During
nighttime driving, system
performance is limited.Front pedestrian protection can be
set to Off, Alert, or Alert & Brake in
vehicle personalisation 3 126.9 Danger
Front pedestrian braking does not
provide an alert or automatically
brake the vehicle, unless it detects
a pedestrian.
The system may not detect
pedestrians, including children,
when the pedestrian is not directly ahead, not fully visible, not
standing upright, or when part of a
group.
Front pedestrian protection includes:
● detecting front pedestrian ahead● front pedestrian alert
● automatic braking
Page 208 of 323

206Driving and operatingDetecting front pedestrian ahead
A pedestrian ahead up to a distance
of approximately 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, a red flashing
LED alert or the pop-up symbol 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. A firm
press of the accelerator pedal will
also release Automatic braking and
Electric parking brake 3 180.
This system includes Intelligent brake assist, and the Emergency automatic
braking system may also respond to
pedestrians. See Active emergency
braking 3 202.
Automatic braking can be disabled in
the vehicle personalisation menu
3 126.
General information9 Warning
The driver must always be ready
to take action and apply the brakes and steer to avoid collisions.