162Driving and operatingOverrun 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.
Depending on driving conditions, the
overrun cut-off may be deactivated.
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. The ignition stays on.
Activation
The stop-start system is activated as
soon as the engine is started, the
vehicle starts-off and the conditions
as stated below in this section are
fulfilled.Deactivation
Deactivate the stop-start system
manually by pressing Ò. Deactivation
is indicated when the LED in the
button illuminates.
Autostop
Vehicles with manual transmission
An Autostop can be activated at a
standstill or at a low speed up to
14 km/h.Activate a conventional 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.
Indication
An Autostop is indicated by the
needle at the AUTOSTOP position in
the tachometer.
After restarting, the idle speed is
indicated.
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.
196Driving and operatingIf no action is performed while the
message is displayed, the last set offset will be used and the message
disappears after 3 seconds.
The new set speed including offset is displayed in the Driver Information
Centre.
System limitations
Intelligent adaptive cruise control has
the same limitations as the traffic sign assistant 3 220.
Implicit speed limits may be
considered with a delay, e.g. city entry, city exit, or motorway entry
signs.
The system may ignore a particular
traffic sign or use a wrong speed limit.
A new speed limit from the navigation may be taken over automatically after
a certain distance since the last
detected traffic sign or when entering
a new road segment, e.g. road exits
or round-abouts.Forward collision alert
The forward collision alert is part of
the forward collision system 3 124. It
can help to avoid or reduce the harm
caused by front-end crashes.
A vehicle ahead is indicated by the
control indicator A.
Additionally, the status of the forward
collision alert is indicated on the
Driver Assistance page in the Driver
Information Center 3 112.
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
and front camera to detect a vehicle
directly ahead, in your path.
Forward collision alert with front
camera detects vehicles to distances
of approx. 60 m and operates
automatically at all speeds above
walking speed.Forward collision alert with radar
sensor detects vehicles to distances
of approx. 150 m and operates
automatically at all speeds above
walking speed.
Activation
A precondition is that forward collision
alert in the vehicle personalisation
menu is not deactivated 3 124.
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. On
vehicles with head-up display, A is
projected on the windscreen.
The control indicator A changes to
amber when the distance to a
preceding moving vehicle gets too
small.Caution
The colour lighting of this control
indicator does not correspond to
local traffic laws on following