Driving and operating161Press Engine Start/Stop briefly: an
automatic procedure operates the
starter with a short delay until the engine is running, see automatic
starter control.
To switch off the engine when vehicle
is stationary, press
Engine Start/Stop briefly. Automatic
transmission: apply the parking brake
and engage P.
To start the engine during an
Autostop:
Manual transmission: during an
Autostop, the engine can be started
by depressing the clutch pedal
3 162.
Automatic transmission: during an
Autostop, the engine can be started
by releasing the brake pedal 3 162.
Emergency engine shut off during driving
If the engine needs to be switched off during driving in case of emergency,
press Engine Start/Stop for more than
2 seconds or press twice briefly within 5 seconds.9 Danger
Switching off the engine during
driving may cause loss of power
support for brake and steering
systems. Assistance systems and
airbag systems are disabled.
Lighting and brake lights will
extinguish. Therefore power down the 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 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 startsrunning 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.
Driving and operating173Fault
In the event of a fault a vehicle
message is displayed in the Driver
Information Centre.
Vehicle messages 3 123.
6-gear automatic transmission:
electronic transmission control
enables only fourth gear; 8-gear
automatic transmission: electronic
transmission control enables only
third gear. The transmission no
longer shifts automatically.
Have the cause of the fault remedied
by a workshop.
Interruption of power supply In the event of an interruption of
power supply, the selector lever
cannot be moved out of the P
position.
If the vehicle battery is discharged,
start the vehicle using jump leads
3 275.
If the vehicle battery is not the cause
of the fault, release the selector lever.
1. Apply parking brake.
2. Release the selector lever trim from the centre console. Poke
with a finger into the leather
socket beside the selector lever
and pull the trim up carefully, there
is a cable attached to it. Slide trim
slightly forward as it is hinged on
its rear side. Tilt loose trim to the
left side to aviod tensioning the
cable.3. Insert a small stick (e.g. a pen or screwdriver) into the opening nearthe selector lever. Push down the
stick vertically and move the
selector lever out of P. If this
position is engaged again, the
selector lever will be locked again.
Have the cause of the power
supply interruption remedied by a
workshop.
4. Mount the selector lever trim onto
the centre console and refit.
Driving and operating175If a service message is displayed in
the Driver Information Centre, the
system may have limited functionality
(or be completely disabled in some
cases, i.e. the vehicle switches to
Front-wheel drive). Seek the
assistance of a workshop.
Towing the vehicle 3 277.Brakes
The brake system comprises twoindependent brake circuits.
If a brake circuit fails, the vehicle can
still be braked using the other brake
circuit. However, braking effect is
achieved only when the brake pedal
is depressed firmly. Considerably
more force is needed for this. The
braking distance is extended. Seek the assistance of a workshop beforecontinuing the journey.
When the engine is not running, the
support of the brake servo unit
disappears once the brake pedal has
been depressed once or twice.
Braking effect is not reduced, but
braking requires significantly greater
force. It is especially important to bear this in mind when being towed.
Control indicator R 3 107.
Active emergency braking 3 200.
Antilock brake system Antilock brake system (ABS)
prevents the wheels from locking.ABS 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 3 108.
Adaptive brake light During full braking, all three brake
lights flash for the duration of ABS
control.
176Driving and operatingFault9Warning
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
9 Warning
Before leaving the vehicle, check
parking brake status. Control
indicator m must illuminate
constantly.
Electric parking brake
Applying when vehicle is stationary
9 Warning
Pull switch m for a minimum of
1 second until control indicator m
illuminates constantly and electric
parking brake is applied 3 107.
The electric parking brake
operates automatically with
adequate force.
Before leaving the vehicle, check
the electric parking brake status.
Control indicator m 3 107.
The electric parking brake can always
be activated, even if the ignition is off.
Do not operate electric parking brake
system too often without engine
running as this will discharge the vehicle battery.
Releasing
Switch on ignition. Keep foot brake
pedal depressed and then push
switch m.
Drive away function
Vehicles with manual transmission:
Depressing the clutch pedal and then
slightly releasing the clutch pedal and slightly depressing the accelerator
pedal releases the electric parking
brake automatically. This is not
possible when switch m is pulled at
the same time.
Vehicles with automatic transmission: Engaging D and then depressing the
accelerator pedal releases the
electric parking brake automatically.
This is not possible when switch m is
pulled at the same time.
186Driving and operatingAdaptive 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.
To facilitate overtaking a vehicle on
the motorway, the activation of the
turn lights reduces the following
distance for a short time. This function is implemented only on the respective
driver's side depending on left or right
hand drive vehicle configuration.
The adaptive cruise control can store set speed over 30 km/h. On vehicles
with automatic transmissions the
system can brake until a full stop and
drive off from a stop.Adaptive cruise control uses radar
and camera sensors to detect the
vehicles ahead. If no vehicle is
detected in the driving path, the
adaptive cruise control will behave
like a conventional cruise control
3 182.
For additional information including a
video, visit us online.
Adaptive cruise control is mainly
advised to be used on long straight
roads like highways or country roads
with steady traffic. Do not use the
system if it is not advisable to
maintain a constant speed.
Control indicator A 3 111, C 3 111.
Additionally, the status of the
adaptive cruise control is indicated on
the Driver Assistance page in the
Driver Information Center 3 112.9 Warning
The complete driver attention is
always required while driving with
adaptive cruise control. The driver stays fully in control of the vehicle
because the brake pedal, the
accelerator pedal and the cancel
switch have priority over any
adaptive cruise control operation.
Switching on the system
Press v to switch on adaptive cruise
control. C appears in the Driver
Information Centre.
190Driving and operatingAdaptive cruise control in Sport
mode
On vehicles with Flex Ride driving
modes, the driver can slightly
increase the Adaptive cruise control
acceleration when Sport mode is
selected. This function can be
deactivated in the Flex Ride
visualisation menu 3 180.
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 m depending
on vehicle speed.
Forward collision alert 3 196.
If this symbol does not display, or
displays briefly, adaptive cruise
control will not respond to vehicles
ahead.
Indication on Driver Assistance page
If the system is active and a preceding vehicle is detected, the bars in front of the vehicle symbol appear green and
indicate set gap position.
Deactivation 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 4 seconds.
● Selector lever of automatic transmission is moved to N.
Driving and operating193If 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. Furthermore,
adaptive cruise control was designed to brake as late as possible to allow
changing the lane before the
automatic braking. 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 if the visibility is
reduced due to weather conditions.
While entering or exiting a motorway, adaptive cruise control may lose thevehicle 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 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. Full speed range
adaptive control is deactivated
automatically, as the vehicle is
stopping uphill on an incline greater than 10%. In this condition, be
prepared to take control of the
vehicle.
Note that applying the brake
deactivates the system.
Driving and operating201If equipped only with front camera the
active emergency braking operates in
forward gear above walking speed up to 80 km/h.
If equipped with radar sensor, active
emergency braking operates in
forward gear at all speeds above
walking speed. Only front pedestrian
protection is active up to 80 km/h.
Activation A precondition is that Forward
Collision System and Front
pedestrian detection are not
deactivated in the vehicle
personalisation menu 3 124.
Brake preparation system When approaching a vehicle ahead
or a pedestrian 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.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.
If active emergency braking is
applied, a message appears in the Driver Information Center and a
chime sounds.
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
3 196. On vehicles with front
pedestrian protection, front automatic
braking can also occur when a
pedestrian ahead is detected.
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.