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Driving and operating159Power button
Electronic key must be inside the
vehicle.
Accessory power mode
Press Engine Start/Stop once without
operating clutch or brake pedal. The yellow LED in the button illuminates.
Steering wheel lock is released and
some electrical functions are
operable, ignition is off.Ignition on power mode
Press and hold Engine Start/Stop for
six seconds without operating clutch
or brake pedal. The green LED in the button illuminates, diesel engine ispreheating. Control indicators
illuminate and most electrical
functions are operable.Engine start
Press Engine Start/Stop briefly while:
● manual transmission: operating clutch pedal,
● automatic transmission: operating brake pedal with
selector lever in P or N.
Starting the engine 3 160.Ignition off
Press Engine Start/Stop briefly when
Autostop is activated or when engine is running and vehicle is stationary.
Automatic transmission: apply the
parking brake and engage P.
Press Engine Start/Stop briefly
without operating clutch or brake pedal when in ignition on power
mode.
Some functions remain active until
driver's door is opened, provided the
ignition was on previously.Emergency engine shut off during
driving
Press Engine Start/Stop for more
than 2 seconds or press twice briefly
within 5 seconds 3 160.
Steering wheel lock The steering wheel lock activates
automatically when:
● The vehicle is stationary.
● The ignition has been switched off.
● The driver's door is opened.
To release steering wheel lock, open
and close driver's door and switch on accessory mode or start the engine
directly.9 Warning
If the vehicle battery is discharged,
the vehicle must not be towed,
tow-started or jump-started as the
steering wheel lock cannot be
disengaged.
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160Driving and operatingOperation on vehicles with
electronic key system in case of
failure
If either the electronic key fails or the
battery of the electronic key is weak,
the Driver Information Centre may
display No Remote Detected or
Replace Battery in Remote Key when
you try to start the vehicle.
Open the cover of the centre console
in front of the selector lever. Place the
electronic key across with buttons
upside in the transmitter pocket
beside the power outlet, as shown in
the illustration.
Other objects, e.g. other keys,
transponder, tags, coins etc. must be
removed from the pocket.
Depress the clutch pedal (manual
transmission), the brake pedal and
press Engine Start/Stop . Release the
button after starting procedure
begins.
To switch off the engine, press
Engine Start/Stop again. Remove the
electronic key from the transmitter
pocket.
This option is intended for
emergencies only. Replace the
electronic key battery as soon as
possible 3 22.
For unlocking or locking the doors,
see fault in radio remote control unit
or electronic key system 3 25.
Retained power off The following electronic systems can
work until the driver's door is opened
or for 10 minutes after the ignition is switched off:● power windows
● sunroof
● power outlets
Starting the engine
Vehicles with power button
Manual transmission: operate clutch
and brake pedal.
Automatic transmission: operate
brake pedal and move selector lever
to P or N.
Do not operate accelerator pedal.
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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.
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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.
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Driving and operating163During an Autostop, the heating and
brake performance will be
maintained.
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.● Between the last restart and a new Autostop must be about10 seconds.
● The self-cleaning function of the exhaust filter is not active.
● The vehicle was driven at least at
walking speed since the last
Autostop.
Otherwise an Autostop will be
inhibited.
The stop-start system will be
deactivated on inclines of 12% or
more.
Certain settings of the climate control
system may inhibit an Autostop. See
Climate control chapter for more
details 3 145.
Immediately after motorway driving,
an Autostop may be inhibited.
New vehicle running-in 3 158.
Vehicle battery discharge protection
To ensure reliable engine restarts,
several battery discharge protection
features are implemented as part of
the stop-start system.Power saving measures
During an Autostop, several electrical
features e.g. auxiliary electric heater
or heated rear window are disabled or
switched to a power saving mode.
The fan speed of the climate control
system is reduced to save power.
Restart of the engine by the driver
Vehicles with manual transmission
All engines can be restarted in two
ways: with a conventional restart or a
late restart.Conventional restart
Depress the clutch pedal without
depressing the brake pedal to restart
the engine.Late restart
Late restart is only available on
inclines up to 5%.
● Depress the brake pedal.
● Depress the clutch pedal.
● Select first gear.
● Release the brake pedal to restart the engine.
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164Driving and operatingVehicles with automatic transmission
Release the brake pedal or move selector lever out of D into N or P to
restart the engine.
Restart of the engine by the stop- start system
The selector lever must be in neutral to enable an automatic restart.
If one of the following conditions
occurs during an Autostop, the
engine will be restarted automatically
by the stop-start system:
● The stop-start system is manually deactivated.
● The bonnet is opened.
● The driver's seat belt is unfastened and the driver's door
is opened.
● The engine temperature is too low.
● The charging level of the vehicle battery is below a defined level.
● The brake vacuum is not sufficient.
● The vehicle is driven at least at walking speed.● The climate control systemrequests an engine start.
● The air conditioning is manually switched on.
If the bonnet is not fully closed, a warning message is displayed in the
Driver Information Centre.
If an electrical accessory, e.g. a
portable CD player, is connected to
the power outlet, a brief power drop
during the restart might be noticeable.
Note
If a trailer or a bike carrier is
attached, late restart is deactivated.
Parking9 Warning
● Do not park the vehicle on an
easily ignitable surface. The
high temperature of the
exhaust system could ignite the
surface.
● Always apply the parking brake. Pull switch m for
approx. 1 second and check if
the control indicator m
illuminates.
The electric parking brake is
applied when control indicator
m illuminates 3 107.
● Switch off the engine. ● If the vehicle is on a level surface or uphill slope, engage
first gear or set the selector
lever to position P before
switching off ignition. On an
uphill slope, turn the front
wheels away from the kerb.
If the vehicle is on a downhill
slope, engage reverse gear or
set the selector lever to position P before switching off ignition.
Turn the front wheels towards
the kerb.
● Close the windows and the sunroof.
● Switch off ignition with power button. Turn the steering wheel
until the steering wheel lock is
felt to engage.
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Driving and operating165● Lock the vehicle by pressing thebutton on the door handle or the
button e on the remote control.
● Activate the anti-theft alarm system.
● The engine cooling fans may run
after the engine has been
switched off 3 237.Caution
After running at high engine
speeds or with high engine loads,
operate the engine briefly at a low load or run in neutral for
approx. 30 seconds before
switching off, in order to protect
the turbocharger.
Note
In the event of an accident with
airbag deployment, the engine is
turned off automatically if the vehicle
comes to a standstill within a certain time.
Engine exhaust9 Danger
Engine exhaust gases contain
poisonous carbon monoxide,
which is colourless and odourless and could be fatal if inhaled.
If exhaust gases enter the interior
of the vehicle, open the windows.
Have the cause of the fault
rectified by a workshop.
Avoid driving with an open load
compartment, otherwise exhaust
gases could enter the vehicle.
Exhaust filter
The exhaust filter is a particle filter for diesel and gasoline engines.
Automatic cleaning process
The exhaust filter system filters soot particles out of the exhaust gases.
The system includes a self-cleaning
function that runs automatically
during driving without any notification. The filter is cleaned by periodically
burning off the soot particles at high
temperature. This process takes
place automatically under set driving
conditions and may take up to
25 minutes. Typically it needs
between seven and twelve minutes.
Autostop is not available and fuel
consumption may be higher during
this period. The emission of smells
and smoke during this process is
normal.
System requires cleaning Under certain conditions, e.g. drivingshort distances, the system cannot
clean itself automatically.
If cleaning of the filter is required and
if previous driving conditions did not
enable automatic cleaning, it will be
indicated by a warning message in
the Driver Information Centre.
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166Driving and operatingA warning message appears when
exhaust filter is full. Start cleaning
process as soon as possible.
A warning message also appears
when exhaust filter has reached the
maximum filling level. Start cleaning
process immediately to avoid
damage to the engine.
Activate self-cleaning process
To activate cleaning process,
continue driving, keep engine speed
above 2000 rpm. Shift down if
necessary. Exhaust filter cleaning is
then started.
Cleaning process is completed more
quickly at high engine speeds and
loads.
Keep on driving until self-cleaning
operation is complete and the display message disappears.Caution
If possible, do not interrupt
cleaning process. Drive until
cleaning is completed to avoid the need for service or repair by a
workshop.
Cleaning process not possible
If cleaning is not possible for anyreason, control indicator Z
illuminates and a warning message
appears in the Driver Information
Centre. Engine power may be
reduced. Seek the assistance of a
workshop immediately.
Catalytic converter
The catalytic converter reduces the
amount of harmful substances in the
exhaust gases.
Caution
Fuel grades other than those listed on pages 3 227, 3 291 could
damage the catalytic converter or
electronic components.
Unburnt petrol will overheat and
damage the catalytic converter.
Therefore avoid excessive use of the starter, running the fuel tank
dry and starting the engine by
pushing or towing.
In the event of misfiring, uneven
engine running, a reduction in engine performance or other unusual
problems, have the cause of the fault
rectified by a workshop as soon as
possible. In an emergency, driving
can be continued for a short period,
keeping vehicle speed and engine
speed low.