226Driving and operatingDeactivation of the functionality
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
45 km/h.
● The Traction Control system is operating.
● Electronic Stability Control is operating.
● There is no traffic and nothing detected on the road sides forseveral minutes. 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.
● Radar sensor is blocked by an ice
or water film.
● A fault is detected in the radar, engine or brake system.
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 and
indicated in brackets in the Driver
Information Centre. 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 the system
Press C to switch off adaptive cruise
control. The control indicator m and
C in the Driver Information Centre
extinguish. 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 mountainroads, as it can lose the vehicle
ahead and require 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 completely suppresses the
Driving and operating227visibility. In case of sensor
blockage, clean the sensor
cover.
System limits ● The system's automatic brake force does not permit hard
braking and the braking level
may not be sufficient to avoid a
collision.
● After a sudden lane change, the system needs a certain time to
detect the next preceding
vehicle. So if a new vehicle is
detected, the system may
accelerate instead of braking.
● Adaptive cruise control does ignore the oncoming traffic.
● Adaptive cruise control does not brake for pedestrians, animals,very slow speed driving or
stopped vehicles.
● Don't use adaptive cruise control when towing a trailer.Bends
The adaptive cruise control calculates
a predicted path based on the
centrifugal force. This predicted path
considers the current bend
characteristic, but cannot consider a
future bend change. The system may lose the current vehicle ahead or
consider a vehicle which is not in the
actual lane. This can happen when
entering or exiting a bend or if the
bend gets stronger or weaker. If it no
longer detects any vehicle ahead,
then control indicator A will
extinguish.
If 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 in
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 if driving fast or if the
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
228Driving and operatingthe 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 considerations
System performance on hills and
when towing a trailer 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, especially
when towing a trailer, you may have
to brake to maintain or reduce your
speed.
Note that applying the brake
deactivates the system. It is not
recommended to use adaptive cruise
control on steep hills especially when towing a trailer.Radar unit
The radar unit is mounted behind the
radiator grille 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,
Driving and operating229consult a workshop to verify and
correct the adaptive cruise control
sensor position.
Settings
Settings can be changed in the
vehicle personalisation menu in the
Info-Display.
Select the relevant setting in
Settings in the Info-Display.
Info-Display 3 121.
Vehicle personalisation 3 124.
Fault
If the adaptive cruise control does not
work due to temporary conditions
(e.g. blockage by ice) or if there is a
permanent system error, then a
message is displayed in the Driver
Information Centre.
Vehicle messages 3 122.
Forward collision alert The forward collision alert can help to
avoid or reduce the damage caused
by front-end crashes.
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 3 124 or that it
is not deactivated by pressing V
(depending on the system, see
following).
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 3 222.
● Forward collision alert based on
front camera system
on vehicles with traditional cruise
control 3 219.
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
3 124.
230Driving and operatingSelecting the alert sensitivity
The alert sensitivity can be set to
near, medium or far.
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 top line of the Driver
Information Centre.
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.
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.
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 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 and a
warning chime sounds. Depress the
brake pedal, if it is required by the
situation.
Driving and operating233If 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 alert sensitivity
setting instead of following distance setting. 3 222.
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 3 229.
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
3 124.
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.
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.
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.
Vehicle care277No.Circuit16Starter17Transmission control module18Heated rear window19Front power windows20Rear power windows21Rear electrical centre (with fuse
box in the load compartment)
Heated front seats (without fuse box in the load compartment)22Left high beam (Halogen)23–24Right headlight (LED)25Left headlight (LED)26Front fog lights27Diesel fuel heating28Stop-start system29Electric parking brake30ABSNo.Circuit31Adaptive cruise control32Airbag33Adaptive forward lighting/Auto‐
matic light control34Exhaust gas recirculation35Exterior mirror/Rain sensor36Climate control37Canister vent solenoid38Vacuum pump39Central control module40Windscreen washer/Rear
window washer system41Right high beam (Halogen)42Radiator fan43Windscreen wiper44Windscreen wiper45Radiator fan46–No.Circuit47Horn48Radiator fan49Fuel pump50Headlamp levelling/Adaptive
forward lighting51Air shutter52Auxiliary heater/Diesel engine53Transmission control module/
Engine control module54Vacuum pump/Instrument
panel cluster/Heating ventila‐
tion/Air conditioning system
After having changed defective fuses,
close the fuse box cover and press
until it engages.
If the fuse box cover is not closed
correctly, malfunctions may occur.
278Vehicle careInstrument panel fuse box
In left-hand drive vehicles, the fuse
box is behind the storage
compartment in the instrument panel.
Open the compartment and push it to the left to unlock. Fold the
compartment down and remove it.
In right-hand drive vehicles, the fuse
box is located behind a cover in the
glovebox. Open the glovebox, then
open the cover and fold it down.
No.Circuit1Cruise control/Speed limiter/
Adaptive cruise control/Steering wheel controls2Exterior lights/Body control
module3Exterior lights/Body control
module4Infotainment system5Infotainment system/Instrument6Power outlet/Cigarette lighter7Power outlet8Left low beam/Body control
module9Right low beam/Body control
module/Airbag module10Door locks/Body control module11Interior fan12–13Sunblind