188Driving and operatingIncrease speed
With adaptive cruise control active,
hold RES/+ to increase speed
continuously. Push RES/+ repeatedly
to increase speed in small
increments.
Reduce speed With adaptive cruise control active,hold SET/- to decrease speed
continuously. Push SET/- repeatedly
to decrease speed in small
increments.
Resume stored speed
If the system is switched on but
inactive, then turn thumb wheel to
RES/+ at a speed above 25 km/h to
resume the stored speed.
Full speed range adaptive cruise
control on vehicles with automatic transmission
Full speed range adaptive cruise control will maintain a following
headway behind a detected vehicle
and slow your vehicle to a stop behind
that vehicle.In case of a brief stop of the vehicle
ahead the adaptive cruise control will drive off automatically without driveraction. If necessary, press RES/+ or
the accelerator pedal to resume
adaptive cruise control.
If the stopped vehicle ahead was
stopped for a longer time and then
begins to move forward, the green
illuminated vehicle ahead control
indicator A will flash and a warning
chime will sound as a reminder to
check traffic before proceeding.
When the vehicle ahead drives away,
press RES/+ or the accelerator pedal
to resume adaptive cruise control. If
stopped for more than five minutes or
if the driver door is opened and the
driver safety belt is unbuckled, the
electric parking brake is applied
automatically to hold the vehicle.
Control indicator m will illuminate. To
release electric parking brake, press
the accelerator pedal. Electric parking
brake 3 1779 Warning
When full speed range adaptive
cruise control is deactivated or
cancelled, the vehicle will no
longer be held at a stop and can
start to move. Always be prepared to manually apply the brake to hold the vehicle stationary.
Do not leave the vehicle while it is being held at a stop by the full
speed range adaptive cruise
control. Always move selector
lever to park position P and switch
off the ignition before leaving the
vehicle.
Setting the following distance
When adaptive cruise control detects
a slower moving vehicle in the driving path, it will adjust the vehicle speed tomaintain the following distance
selected by the driver.
The following distance can be set to
near, medium or far.
Driving and operating189
Press E, the current setting is shown
in the Driver Information Centre.
Press E again to change the
following distance. The setting is also displayed in the Driver Information
Centre.The selected following distance is
indicated by filled distance bars in the
adaptive cruise control page.
Note that the following distance
setting is shared with the sensitivity
setting of forward collision alert
3 193.
Example: If setting 3 (far) is selected,
then the driver is warned sooner
before a possible collision, also if
adaptive cruise control is inactive or
switched off.
9 Warning
The driver accepts full
responsibility for the appropriate
following distance based on traffic, weather and visibility conditions.
Following distance must be
adjusted or the system switched
off when required by the prevailing
conditions.
Detecting the vehicle ahead
The green illuminated vehicle ahead
control indicator A is displayed when
the system detects a vehicle in the driving path. The range of the sensors
is between 25 and 150 metres
depending on vehicle speed.
Forward collision alert 3 193.
190Driving and operatingIf this symbol does not display, or
displays briefly, adaptive cruise
control will not respond to vehicles
ahead.
Deactivation
Adaptive 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
190 km/h or slows down below
55 km/h (on vehicles with
automatic transmission it slows
down to a stop without
deactivating within five minutes).
● The Traction Control system is deactivated or operating.
● The Electronic Stability Control is
deactivated or operating.● There is no traffic and nothing detected on the road sides for
approx. one minute. 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.
● 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.
192Driving and operatingIf 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 on
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 while driving fast or ifthe 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
the set speed. For this reason,
decrease the set speed before the
exit or before the entry.
Vehicle path changes
If another vehicle enters your driving
path, adaptive cruise control will first
consider the vehicle when it is
completely in your path. Be ready to
take action and depress the brake
pedal, if you need to brake more
quickly.
Hill and trailer considerations9 Warning
Do not use adaptive cruise control
on steep hill roads.
System performance on hills depends
on vehicle speed, vehicle load, traffic
conditions and the road gradient. It
may not detect a vehicle in your path
while driving on hills. On steep hills,
you may have to use the accelerator
pedal to maintain your vehicle speed.
When going downhill you may have to
brake to maintain or reduce your
speed.
Note that applying the brake
deactivates the system.
Driving and operating193Radar unit
The radar unit is mounted behind the
radiator grille behind or below the
brand emblem.
9 Warning
The radar unit was aligned
carefully during manufacture.
Therefore, after a frontal accident, do not use the system. The front
bumper may appear to be intact,
however the sensor behind can be
out of position and react
incorrectly. After an accident,
consult 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.
194Driving and operatingA 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.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 which is projected on the
windscreen in the driver's field of
view.
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 V or E to set the alert
sensitivity to near, medium or far and
on some versions off.
Driving and operating195
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.
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.
Driving and operating197Active 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
supplemental use only to reduce
the vehicle speed before a
collision.
The system may not react for
pedestrians or animals. After a
sudden lane change, the system
needs a certain time to detect the
next preceding vehicle.
The driver shall 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.
A precondition is that forward collision
alert with front camera system is not
deactivated by pressing V on the
steering wheel 3 193or, with radar
sensor, that it is not deactivated in the
vehicle personalisation menu 3 125.
The system includes: ● brake preparation system
● emergency automatic braking
● forward looking brake assist
● intelligent brake assist (only with radar sensor)
Brake preparation system
When approaching a vehicle ahead
so quickly that a collision is likely, the brake preparation system slightlypressurizes 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