Driving and operating161starting 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).
● Brake pedal not operated (manual transmission
automated).
● 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.
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.
The engine switches on automatically
when certain conditions apply or
restart is activated by a driver.
Activation The stop-start system is available assoon 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 D. The
deactivation is indicated when the
LED in the button illuminates.
Autostop
Vehicles with manual transmission
Depending on the engine, two
versions of an Autostop are available. See engine data to identify the engine
identifier code for your vehicle
3 286.
Conventional Autostop
All engines except B16DTU have only
the conventional Autostop.
176Driving and operatingManual mode
To utilise the engine braking effect,
select a lower gear in good time when
driving downhill. Changing into
manual mode is only possible while
the engine is running or during an
Autostop.
Rocking the vehicle
Rocking the vehicle is only
permissible if the vehicle is stuck in
sand, mud or snow. Move the selector
lever between R and D in a repeat
pattern. Do not race the engine and
avoid sudden acceleration.
Parking
The most recently engaged gear (see transmission display) remains
engaged when switching off ignition.
With N, no gear is engaged.
Therefore always apply the parking
brake when switching off ignition. If
parking brake is not applied, P flashes
in the transmission display and the
key cannot be removed from the
ignition switch. P stops flashing in the
transmission display as soon as the
parking brake is slightly applied.When the ignition is switched off, the
transmission no longer responds to
movement of the selector lever.
Emergency operation to avoid
freezing of the parking brake 3 164.
Manual mode
If a higher gear is selected when the
engine speed is too low, or a lower
gear when the speed is too high, the
shift is not executed. This prevents
the engine from running at too low or too high an engine speed. A warning
message is displayed in the Driver
Information Centre. Vehicle
messages 3 122.
If engine speed is too low, the
transmission automatically shifts to a
lower gear.
When + or - is selected in automatic
mode, the transmission switches to
manual mode and shifts accordingly.
Gear shift indication
The symbol R or S with a number
beside is indicated when gearshifting
is recommended for fuel saving
reasons.Shift indication appears only in
manual mode.
Electronic driving programmes
● Following a cold start, the operating temperature
programme increases engine
speed to quickly bring the
catalytic converter to the required
temperature.
● The adaptive programme tailors gearshifting to the driving
conditions, e.g. greater load or
gradients.
Kickdown
If the accelerator pedal is pressed down completely in automatic mode,
the transmission shifts to a lower gear
depending on engine speed.
Fault
To prevent damage to the manual transmission automated, the clutch is engaged automatically at high clutch
temperatures.
Driving and operating177In the event of a fault, a warning
message is displayed in the Driver
Information Centre. Vehicle
messages 3 122.
Continued driving is restricted or not
possible, depending on the fault.
Have the cause of the fault remedied
by a workshop.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 before
continuing 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 3 109.
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 3 110.
Adaptive brake light During full braking, all three brake
lights flash for the duration of ABS
control.
Driving and operating183DeactivationBriefly press SPORT. Sport mode is
deactivated the next time the ignition
is switched on.Driver assistance
systems9 Warning
Driver assistance systems are
developed to support the driver
and not to replace the driver's
attention.
The driver accepts full
responsibility when driving the
vehicle.
When using driver assistance
systems, always take care
regarding the current traffic
situation.
Cruise control
The cruise control can store and
maintain speeds of approx. 20 mph to maximum vehicle speed. Deviations
from the stored speeds may occur
when driving uphill or downhill.
Activating in first gear is not possible.
Do not use the cruise control if it is not advisable to maintain a constant
speed.
Illustrations show different versions.
186Driving and operating
On Uplevel display L changes to
green.
Change 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 of the functionality Press y: speed limiter is deactivated
and the vehicle can be driven without speed limit.
On Midlevel display the stored limited
speed is indicated in brackets.
On Uplevel display L changes to
white.
Additionally, a corresponding
message appears.
Speed limiter is deactivated, but not
switched off. Last stored speed
remains in memory for later speed
resume.
Resume limit speed
Turn thumb wheel to RES/+. The
stored speed limit will be obtained
and is indicated without brackets in the Driver Information Centre.
Switching off the system
Press L, the speed limit indication
extinguishes in the Driver Information Centre. 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 is an
enhancement to conventional cruise control with the additional feature ofmaintaining a certain distance behind the vehicle ahead.
190Driving and operating9Warning
The Driver accepts full
responsibility to drive with the
appropriate following distance
based on traffic, weather, visibility and regional regulation. Followingdistance 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 3 194.
If this symbol does not display, or
displays briefly, adaptive cruise
control will not respond to vehicles ahead.
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 four seconds.
● Selector lever of automatic transmission is moved to N.
The system is also automatically
deactivated when:
● Vehicle speed accelerates above
120 mph or slows down below
15 mph. Vehicles with automatic
transmission 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 need to cool down.
Additionally, the system is
automatically deactivated on vehicles with automatic transmission (full
speed range adaptive cruise control)
when:
● The incline uphill or downhill is greater than 20%.
● The electric parking brake is applied.
192Driving and operating● Adaptive cruise control doesignore the oncoming traffic.
● Adaptive cruise control does not consider pedestrians and
animals for braking and driving off.
● Adaptive cruise control considers
stopped vehicles only at low
speed.
● Do not use adaptive cruise control when towing a trailer.
● Do not use adaptive cruise control on roads with an incline ofmore than 10%.
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. The
camrea applies a certain correction
based on the detectable lane
markings. The control indicator A will
extinguish, if a vehicle ahead is no longer detected.
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 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.
194Driving and operatingFault
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 3 122.
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.
A 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 3 124.
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