154Driving and operatingPower 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 3 155.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 two seconds or press twice
briefly within five seconds 3 155.
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.
Driving and operating155Operation 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 gear shift 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) or the brake pedal
(automatic transmission) and press
Engine Start/Stop .
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 21.
For unlocking or locking the doors,
see fault in radio remote control unit
or electronic key system 3 23.
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 outletsStarting 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.
Press Engine Start/Stop briefly: an
automatic procedure operates the
starter with a short delay until the engine is running.
156Driving and operatingTo switch off the engine when vehicleis stationary, press
Engine Start/Stop briefly. Automatic
transmission: apply the parking brake
and engage P.
Manual transmission: during an
Autostop, the engine can be started
by depressing the clutch pedal
3 157.
Automatic transmission: during an
Autostop, the engine can be started
by releasing the brake pedal 3 157.
Emergency engine shut off during driving
If the engine needs to be switched offduring driving in case of emergency,
press Engine Start/Stop for more than
two seconds or press twice briefly
within five 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.
five 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.
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.
Driving and operating157Stop-start systemThe 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.
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.
DeactivationDeactivate the stop-start system
manually by pressing Ò. Deactivation
is indicated when the LED in the
button illuminates.
AutostopVehicles 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.
During 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.
158Driving and operating● The driver's door is closed or thedriver'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.
● The self-cleaning function of the diesel particle filter is not active.
● The vehicle was driven at least at
walking speed since the last
Autostop.
Otherwise an Autostop will be
inhibited.
Certain settings of the climate control
system may inhibit an Autostop. See
Climate control chapter for more
details 3 140.Immediately after motorway driving,
an Autostop may be inhibited.
New vehicle running-in 3 153.
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 transmissionConventional restart
All engines have conventional restart.
Depress the clutch pedal without
depressing the brake pedal to restart
the engine.
On engines with late restart a
conventional restart is only possible
without depressed brake pedal.Late restart
All engines have late restart in
addition to conventional restart. Late
restart is only active on gradients up to 5%.
● Depress the brake pedal.
● Depress the clutch pedal.
● Select first gear.
● Release the brake pedal to restart the engine.
Vehicles 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.
Driving and operating159● The driver's seat belt isunfastened 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 system requests 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.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. one second and check
if the control indicator m
illuminates.
The electric parking brake is applied when control indicator
m illuminates 3 99.
● 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
removing the ignition key or
switching off ignition on
vehicles with power button. 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 removing the ignition
key or switching off ignition on
vehicles with power button.
Turn the front wheels towards
the kerb.
● Close the windows and the sunroof.
● Remove the ignition key from the ignition switch or switch off
ignition on vehicles with power
button. Turn the steering wheel
until the steering wheel lock is
felt to engage.
For vehicles with automatic
transmission, the key can only
be removed when the selector
lever is in position P.
●
Lock the vehicle with button e on
the radio remote control.
Activate the anti-theft alarm
system 3 30.
● The engine cooling fans may run
after the engine has been
switched off 3 231.
160Driving and operatingCaution
After running at high enginespeeds 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.
Diesel particle filter
Automatic cleaning process
The diesel particle filter system filters
harmful 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 process
Under certain driving conditions, e.g.
short 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
Driving and operating161indicated by % and a warning
message in the Driver Information
Centre.
% with a warning message
illuminates when diesel particle filter
is full. Start cleaning process as soon
as possible.
% with a warning message flashes
when diesel particle 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 revolutions per minute.
Shift down if necessary. Diesel
particle filter cleaning is then started.
Cleaning takes place quickest at high
engine speeds and loads.
The control indicator % extinguishes
as soon as the self-cleaning
operation is complete. Keep on
driving until self-cleaning operation is
complete.Caution
If the cleaning process is
interrupted, there is a risk of
provoking severe engine damage.
Cleaning process not possible
If cleaning is not possible for anyreasons, 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 3 221, 3 280 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.