190Driving and operatingAlerting the driver
A green illuminated vehicle ahead
control indicator A illuminates 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
small 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.
Settings
Settings can be changed in the Auto
collision preparation menu in the
vehicle personalisation 3 129.
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.
Driving and operating191Alerting the driver
A green illuminated vehicle ahead
control indicator A illuminates 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 small 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 the following
message appears in the Driver
Information Centre.
General information for both
variants of forward collision alert
9 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
The system is designed to warn only for vehicles, but may react also onother metallic 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, or
windscreen damage
192Driving and operatingFollowing distanceindication
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 3 116.
Press MENU on the turn signal lever
to select Vehicle Information Menu
X and turn the adjuster wheel to
choose following distance indication
page.
The minimum indicated distance is 0.5 s.
If there is no vehicle ahead or the
vehicle ahead is out of range, two
dashes will be displayed: -.- s.
Active 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 3 188.
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
3 129.
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.
Driving and operating193Brake preparation system
When approaching a vehicle ahead
so quickly that a collision is likely, the brake preparation system slightlypressurises 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.9 Warning
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 Auto
collision preparation menu in the
vehicle personalisation, 3 129.
Fault
In the event of a system service
requirement, a message is displayed
in the Driver Information Centre.
194Driving and operating
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. 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 via the rear speakers.
Driving and operating195Parking assist button D and
operation logic
Front-rear parking assist is equipped
with D. If the vehicle is additionally
equipped with advanced parking
assist (see the following separate
description), both systems will be
operated by pressing D.
Short press on D deactivates or
activates the front parking assist.
Long press on D (approx.
one second) activates or deactivates
the advanced parking assist.
Button logic to operate the systems is as follows:
● Front-rear parking assist is active: short press deactivates
front-rear parking assist.
● Front-rear parking assist is active: long press activates
advanced parking assist if a
forward gear is engaged.
● Advanced parking assist is active: short press activates
front-rear parking assist.
● Advanced parking assist is active: long press deactivates
advanced parking assist.
● Advanced parking assist and front-rear parking assist are
active: short press deactivates
both systems.
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 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 may be shown in the Driver
Information Centre 3 116.
196Driving 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, 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 D 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
D 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, control indicator
r illuminates or a message is
displayed in the Driver Information
Centre.
Vehicle messages 3 122.
Control indicator r 3 113.
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.
200Driving and operatingBasic notes on parking assist
systems9 Warning
Under certain circumstances,
various reflective surfaces on
objects or clothing as well as
external noise sources may cause the system to fail to detect
obstacles.
Special attention must be paid to
low obstacles which can damage
the lower part of the bumper.
Caution
Performance of the system can be reduced when sensors are
covered, e.g. by ice or snow.
Performance of the parking assist
system can be reduced due to
heavy loading.
Special conditions apply if there
are taller vehicles in the vicinity
(e.g. off-road vehicles, mini vans,
vans). Object identification and
correct distance indication in the
upper part of these vehicles
cannot be guaranteed.
Objects with a very small reflection
cross-section, e.g. objects of
narrow size or soft materials, may
not be detected by the system.
Parking assist systems do not
detect objects outside the
detection range.
Notice
The parking assist system can be
activated and deactivated by
changing the settings in the
Info-Display. If a trailer coupling is
attached, it must be selected in the
menu.
Vehicle personalisation 3 129.
Notice
The parking assist system
automatically detects factory-fitted
towing equipment. It is deactivated
when the connector is plugged in.
It is possible that the sensor detects
a non-existing object (echo
disturbance) caused by external acoustical or mechanic
disturbances.
Advanced parking assist system
may not respond to changes in the
parking space after initiating a
parallel parking manoeuvre.
Notice
If engaging a forward gear and
exceeding a certain speed, the rear
parking assist will be deactivated
when the rear carrier system is
extended.
If engaging reverse gear first, the
parking assist will detect the rear
carrier system and provide a buzzing sound. Press D briefly to
deactivate the parking assist.
Notice
After production, the advanced
parking assist requires a calibration.
For optimal parking guidance, a
driving distance of at least 22 miles,
including a number of bends, is
required.