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Driving and operating1990:ignition off: Some functions
remain active until key is
removed or driver's door is
opened, provided the ignition was
on previously1:accessory power mode: Steering wheel lock released, some
electrical functions are operable,
ignition is off2:ignition on power mode: Ignition
is on, diesel engine is preheating.
Control indicators illuminate and
most electrical functions are
operable3:engine start: Release key after
starting procedure beginsSteering wheel lock
Remove key from ignition switch and
turn steering wheel until it engages.9 Danger
Never remove the key from
ignition switch during driving as
this will cause steering wheel lock.
Retained power off
The following electronic systems can
work until the driver's door is opened
or for ten minutes after the ignition is
switched off:
● power windows
● power outlets
Starting the engine
Turn key to position 1 to release the
steering wheel lock.
Manual transmission: operate clutch
and brake pedal.
Automatic transmission: operate
brake pedal and move selector lever
to P or N.
Do not operate the accelerator pedal. Diesel engines: turn the key to
position 2 for preheating and wait until
control indicator ! extinguishes.
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200Driving and operatingTurn key briefly to position 3 and
release: an automatic procedure
operates the starter with a short delay
until the engine is running, see
Automatic Starter Control.
Manual transmission: during an
Autostop, the engine can be started
by depressing the clutch pedal
3 201.
Automatic transmission: during an
Autostop, the engine can be started
by releasing the brake pedal 3 201.
Before restarting or to switch off the engine, turn the key back to position
0 .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
The start of 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 battery.
With temperatures below -30 °C the
automatic transmission need 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 have to hold the key in position 3.
Once applied, the system will go on
starting 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).
● 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.
Page 203 of 341

Driving and operating201Stop-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. It starts the engine
automatically as soon as the clutch is
depressed. A vehicle battery sensor
ensures that an Autostop is only
performed if the vehicle battery is
sufficiently charged for a restart.
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.Deactivation
Deactivate the stop-start system
manually by pressing eco. The
deactivation is indicated when the
LED in the button extinguishes.
Autostop If the vehicle is at a low speed or at a
standstill, activate an Autostop as
follows:
● Depress the clutch pedal.
● Move the selector 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 restart, the idle speed is
indicated.
The stop-start system will be disabled
on inclines of 12% or more.
During an Autostop, the heating and
brake performance will be
maintained.
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202Driving and operatingConditions 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.
● 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.
Certain settings of the climate control
system may inhibit an Autostop. See
Climate control chapter for more
details 3 191.
Immediately after motorway driving,
an Autostop may be inhibited.
New vehicle running-in 3 198.
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 such as auxiliary electric
heater or rear window heating are
disabled or switched into a power-
saving mode. The fan speed of the
climate control system is reduced to
save power.
Restart of the engine by the driver Depress the clutch pedal to restart the
engine.When the engine is restarted, control
indicator D in the Driver Information
Centre extinguishes.
If the selector lever is shifted out of
neutral before depressing the clutch
pedal first, control indicator -
illuminates or is shown as a message
in the Driver Information Centre.
Control indicator - 3 112.
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.
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Driving and operating203● The charge level of the vehiclebattery 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 engine restart may 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. Activate the manual
parking brake without pressing the release button. Apply as
firmly as possible on a downhill slope or uphill slope. Depress
brake pedal at the same time to
reduce operating force.
For vehicles with electric
parking brake, pull switch m for
a minimum of one second until
control indicator m illuminates
constantly and electric parking
brake is applied 3 112.
● 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. 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. Turn the front wheels
towards the kerb.
● Close the windows.
● Remove the ignition key from the ignition switch. 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.
● Activate the anti-theft alarm system.
● The engine cooling fans may run
after the engine has been
switched off 3 260.
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204Driving 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.
Exhaust filter
The exhaust filter is a particle filter for diesel and gasoline engines.
Automatic cleaning process
The exhaust 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
Under certain conditions, e.g. driving
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
indicated by illumination of % and a
warning message in the Driver Information Centre.
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Driving and operating205% illuminates along with a warning
message when exhaust filter is full.
Start cleaning process as soon as
possible.
% flashes along with a warning
message 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.
Control indicator % extinguishes as
soon as the self-cleaning operation is
complete. Keep on driving until self-
cleaning operation is complete.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 3 245, 3 312 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.
Page 208 of 341

206Driving and operatingAdBlue
General information The selective catalytic reduction
(BlueInjection) is a method to
substantially reduce the nitrogen
oxides in the exhaust emission. This
is achieved by injecting a Diesel
Exhaust Fluid (DEF) into the exhaust system. The ammonia released by
the fluid reacts with nitrous gases
(NO x) from the exhaust and turns it
into nitrogen and water.
The designation of this fluid is
AdBlue ®
. It is a non-toxic, non-
flammable, colourless and odourless
fluid which consists of 32% urea and
68% water.9 Warning
Avoid contact of your eyes or skin
with AdBlue.
In case of eye or skin contact,
rinse off with water.
Caution
Avoid contact of the paintwork with AdBlue.
In case of contact, rinse off with water.
AdBlue freezes at a temperature of
approx. -11 °C. As the vehicle is
equipped with an AdBlue pre-heater,
the emissions reduction at low
temperatures is ensured. The AdBlue
pre-heater works automatically.
The typical AdBlue consumption is
approx. 1.2 litres per 1000 km for
vehicles with engine B16DTH or
B16DTJ and approx. two litres per
1000 km for vehicles with engine
B20DTH. The consumption can also
be higher depending on driving
behaviour (e.g. high load or towing).
AdBlue tank
At a remaining volume of approx. five litres, there is a liquid level switch.
Warning messages are displayed
only below that threshold. Tank
volume 3 317.
Level warnings
Depending on the calculated range of AdBlue, different messages are
displayed in the Driver Information
Centre. The messages and the
restrictions are a legal requirement.
The first possible warning is AdBlue
Range: 2400 km .
This warning will show up once briefly with the calculated range. Driving is
possible without any restrictions.
The next warning level is entered with
a range below 1750 km. The
message with the current range will
always be displayed when ignition is
switched on and needs to be
confirmed 3 117 . Refill AdBlue before
entering the next warning level.
At an AdBlue range below 900 km,
the following warning messages are
alternately displayed and cannot be
dismissed:
● AdBlue Low Refill Now
● Engine Restart Prevented in 900
km .
Additionally, control indicator Y
flashes continuously.