Driving and operating159extinguish. Therefore power downthe engine and ignition while
driving only when required in case
of emergency.
Starting the vehicle at low
temperatures
Starting the engine without additional heaters is possible down to -25 °С for
diesel engines and -30 °C for petrol
engines. Required is an engine oil
with the correct viscosity, the correct
fuel, performed services and a
sufficiently charged vehicle battery.
With temperatures below -30 °C the
automatic transmission requires a
warming phase of approx. 5 minutes.
The selector lever must be in position
P .
Automatic Starter Control
This function controls the engine
starting procedure. The driver does
not need to hold the key in position 3
or to hold Engine Start/Stop pressed.
Once applied, the system will go on starting automatically until the engine
is running. Because of the checking
procedure, the engine starts running
after a short delay.
Possible reasons for a non-starting
engine:
● Clutch pedal not operated (manual transmission).
● Brake pedal not operated or selector lever not in P or N
(automatic transmission).
● Timeout occurred.
Turbo engine warm-up
Upon start-up, engine available
torque may be limited for a short time, especially when the engine
temperature is cold. The limitation is
to allow the lubrication system to fully protect the engine.
Overrun cut-off The fuel supply is automatically cut-
off during overrun, i.e. when the
vehicle is driven with a gear engaged
but accelerator pedal is released.Stop-start system
The stop-start system helps to save
fuel and to reduce the exhaust
emissions. When conditions allow, it
switches off the engine as soon as the
vehicle is at a low speed or at a
standstill, e.g. at a traffic light or in a
traffic jam. It starts the engine
automatically as soon as the clutch is depressed. A battery sensor ensures
that an Autostop is only performed if
the vehicle battery is sufficiently
charged for a restart.
Activation
The stop-start system is available as
soon as the engine is started, the
vehicle starts-off and the conditions
as stated below in this section are
fulfilled.
160Driving and operatingDeactivation
Deactivate the stop-start system
manually by pressing eco. The
deactivation is indicated when the
LED in the button extinguishes.
Autostop If the vehicle is at a low speed or at a
standstill, activate an Autostop as
follows:
● Depress the clutch pedal.
● Set the lever to neutral.
● Release the clutch pedal.
The engine will be switched off while
the ignition stays on.
An Autostop is indicated by the
needle at the AUTOSTOP position in
the tachometer. On some versions a
control indicator in the instrument
cluster lights up when engine is in
Autostop.
During an Autostop, the heating and
brake performance will be
maintained.
Caution
The steering assist can be
reduced during an Autostop.
Conditions for an Autostop
The stop-start system checks if each
of the following conditions is fulfilled.
● The stop-start system is not manually deactivated.
● The bonnet is fully closed.
● The driver's door is closed or the driver's seat belt is fastened.
● The vehicle battery is sufficiently charged and in good condition.
● The engine is warmed up.
● The engine coolant temperature is not too high.
● The engine exhaust temperature is not too high, e.g. after driving
with high engine load.
● The ambient temperature is above -5 °C.
● The climate control system allows an Autostop.
● The brake vacuum is sufficient.
Driving and operating173ABS starts to regulate brake pressure
as soon as a wheel shows a tendency to lock. The vehicle remains
steerable, even during hard braking.
ABS control is made apparent
through a pulse in the brake pedal
and the noise of the regulation
process.
For optimum braking, keep the brake
pedal fully depressed throughout the
braking process, despite the fact that
the pedal is pulsating. Do not reduce
the pressure on the pedal.
After starting off, the system performs a self-test which may be audible.
Control indicator u 3 106.
Adaptive brake light During full braking, all three brake
lights flash for the duration of ABS
control.
Fault9 Warning
If there is a fault in the ABS, the
wheels may be liable to lock due
to braking that is heavier than
normal. The advantages of ABS are no longer available. During
hard braking, the vehicle can no longer be steered and may
swerve.
Have the cause of the fault remedied
by a workshop.
Parking brake
Manual parking brake9 Warning
Always apply parking brake firmly
without operating the release
button, and apply as firmly as
possible on a downhill or uphill
slope.
To release the parking brake, pull
the lever up slightly, press the
release button and fully lower the
lever.
Driving and operating183Change speed limit
With speed limiter active, hold or
briefly turn thumb wheel to RES/+ to
increase or SET/- to decrease the
desired maximum speed.
Exceeding the speed limit
When exceeding the limited speed
without driver input, the speed will
flash in the Driver Information Centre
and a chime sounds during this
period.
In the event of an emergency, it is
possible to exceed the speed limit by
depressing the accelerator pedal
firmly nearly to the final point. In this
case no chime appears.
Release the accelerator pedal and the speed limiter function is
reactivated once a speed lower than
the limit speed is obtained.
Deactivation Press y: speed limiter is deactivated
and the vehicle can be driven without
speed limit.The limited speed will be stored and
is indicated in brackets in the Driver
Information Centre. Additionally, a
corresponding message appears.
Resume limit speed
Turn thumb wheel to RES/+. The
stored speed limit will be obtained.
Switching off
Press L, the speed limit indication in
the Driver Information Centre
extinguishes. The stored speed is
deleted.
By pressing m to activate cruise
control or adaptive cruise control,
speed limiter is also deactivated and
the stored speed is deleted.
By switching off the ignition, speed
limiter is also deactivated, but the
speed limit will be stored for next
speed limiter activation.Adaptive cruise control
Adaptive cruise control (ACC) is an
enhancement to traditional cruise
control with the additional feature of
maintaining a certain distance behind the vehicle ahead.
Adaptive cruise control automatically decelerates the vehicle when
approaching a slower moving vehicle. It then adjusts the vehicle speed to
follow the vehicle ahead at the
selected following distance. The
vehicle speed increases or decreases
to follow the vehicle in front, but will
not exceed the set speed. It may
apply limited braking with activated
brake lights.
The adaptive cruise control can store and maintain speeds over approx.
15 mph. If following a vehicle ahead
driving slower than 15 mph, the
slower speed will be set. On vehicles
with automatic transmission, the
system brakes to a stop.
Driving and operating189If 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 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
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 press the brake
pedal, if you need to brake more
quickly.
Hill and trailer considerations
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. It is not
recommended to use adaptive cruise
control on steep hills.
192Driving and operating
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
A green illuminated vehicle ahead
control indicator A illuminates 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.
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.
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 3 121.
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.
Driving and operating1959Warning
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
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 wearingtheir 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.
Driving and operating205Select the relevant setting in Settings,
I Vehicle in the Colour-Info-Display.
Colour-Info-Display 3 117.
Vehicle personalisation 3 121.
The system is deactivated if the
vehicle is towing a trailer.
Deactivation is indicated by a
message in the Driver Information
Centre.
Notice
After production, the system
requires a calibration. For optimal
performance, drive as soon as
possible on a straight highway road
with roadside objects, e.g. guardrails
and barriers for some distance.
Fault
Occasional missed alerts can occur under normal circumstances or in
sharp curves. The system can
temporarily alert of objects in the blind spot at specific weather conditions(rain, hail etc). Driving on a wet road
or in the transitions from a dry area to a wet area can cause the system to
light up, as water splash can be
interpreted as an object. Otherwisethe system may light up due to
guardrails, signs, trees, shrubs or
other immobile objects. This is normal
operation and the system does not
need to be serviced.
Lane change alert may not operate
when the left or right corners of the
rear bumper are covered with mud,
dirt, snow, ice or slush. Cleaning
instructions 3 270.
In the event of a fault in the system or if the system does not work due to
temporary conditions, a message is
displayed in the Driver Information
Centre. Seek the assistance of a
workshop.
Rear view camera The rear view camera assists the
driver when reversing, by displaying a
view of the area behind the vehicle.
The view of the camera is displayed
in the Colour-Info-Display.9 Warning
The rear view camera does not
replace driver vision. Note that
objects that are outside the
camera's field of view and the
advanced parking assist sensors,
e.g. below the bumper or
underneath the vehicle, are not
displayed.
Do not reverse the vehicle by only looking at the Info-Display and
check the surrounding area
behind and around the vehicle
before reversing.
Activation
Rear view camera is automatically
activated when reverse gear is
engaged.