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Driving and operating159extinguish. Therefore power downthe 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 the key in position 3
or 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 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.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. It starts the engine
automatically as soon as the clutch is depressed. A 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.
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160Driving and operatingDeactivation
Deactivate the stop-start system
manually by pressing eco.
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.
An Autostop is indicated by the
needle at the AUTOSTOP position in
the tachometer. On some versions, a control indicator in the instrument
cluster illuminates when engine is in
Autostop.
During an Autostop, the heating and
brake performance will be
maintained.Caution
The steering assist can be
reduced during an Autostop.
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.
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Driving and operating161● The climate control systemallows 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 3 155.
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 orswitched 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 Depress the clutch pedal to restart the
engine.
The engine start is indicated by the
needle at the idle speed position in
the tachometer.
If the selector lever is shifted out of
neutral before depressing the clutch
first, control indicator - illuminates
or is shown as a symbol in the Driver
Information Centre.
Control indicator - 3 105.
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 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.
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162Driving and operatingParking9Warning
● 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
approx. one second.
The electric parking brake is
applied when control indicator
m illuminates 3 105.
● 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 34.
● The engine cooling fans may run
after the engine has been
switched off 3 226.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.
Notice
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.
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Driving and operating163Engine exhaust9Danger
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
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 7 and 12 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.
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
indicated 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.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.Caution
If the cleaning process is
interrupted, there is a risk of
provoking severe engine damage.
If cleaning is not possible for any
reasons, Z illuminates and a warning
message appears in the Driver
Information Centre. Engine power
may be reduced. Seek the assistance
of a workshop immediately.
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.
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164Driving and operatingCatalytic converter
The catalytic converter reduces the
amount of harmful substances in the
exhaust gases.Caution
Fuel grades other than those listed on pages 3 213, 3 281 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.
AdBlue
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 designation of this fluid is AdBlue Ⓡ 1)
. It is a non-toxic, non-flammable,
colourless and odourless fluid which
consists of 32% urea and 68% water.9Warning
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.
Level warnings
The AdBlue consumption is approx.
4000 mpg and depends on the driving
behaviour.
If the AdBlue level falls below a
certain value, a level warning AdBlue
Range: 1500 mi will be displayed in
the Driver Information Centre.
A volume of at least 5 litres of AdBlue must be refilled as soon as possible.
Driving is possible without any
restrictions.
1) Registered trademark of the Verband der Automobilindustrie e.V. (VDA).
Page 167 of 325

Driving and operating165If AdBlue is not refilled within a certain
distance, further level warnings are
displayed in the Driver Information Centre depending on the current
AdBlue level. Later on requests to
refill AdBlue and finally the
announcement to prevent an engine
restart are displayed. These
restrictions are a legal requirement.
At an AdBlue range of 560 miles, the
following warning messages are
alternately displayed in the Driver
Information Centre:
● AdBlue Low Refill Now
● Engine Restart Prevented in 560
miles
Additionally, control indicator Y
flashes continuously and a warning
chime sounds four times every
three minutes.
Before the prevention of an engine restart is activated, the following
warning messages:
● AdBlue Empty Refill Now
● Engine Will Not Restart
are alternately displayed in the Driver
Information Centre.Additionally, control indicator Y
flashes continuously and a warning
chime sounds four times every
three minutes.
After the prevention of an engine
start, the following message:
Refill AdBlue To Start Vehicle
will be displayed.
To restart the engine, the tank must be filled with AdBlue first.
High emission warnings
If the exhaust emission rises above a certain value, warnings similar to the
range warnings as described above
will be displayed in the Driver
Information Centre.
Requests to have the exhaust system
checked and finally the
announcement to prevent an engine
restart are displayed. These
restrictions are a legal requirement.
Seek your workshop for assistance.Refilling AdBlueCaution
Only use AdBlue that complies
with European standards
DIN 70 070 and ISO 22241-1.
Do not use additives.
Do not dilute AdBlue.
Otherwise the selective catalytic
reduction system could be
damaged.
Notice
Only use the designated AdBlue canisters for refilling, to prevent a
topping-up of too much AdBlue.
Additionally, the fumes in the tank
are captured in the canister and do
not emerge.
Since AdBlue has a limited
durability, check the date of expiry
before refilling.
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166Driving and operatingNotice
A volume of at least 5 litres of AdBlue must be added when refilling.
Otherwise the refilling of AdBlue
may not be detected by the system.
In case AdBlue refill is not
successfully detected:
1. Continuously drive the vehicle for 10 minutes making sure that
vehicle speed is always higher
than 12 mph.
2. If AdBlue refill is detected successfully, AdBlue supply-
driven limitations will disappear.
If AdBlue refill is still not detected,
seek the assistance of a workshop.
If AdBlue must be refilled at
temperatures below -11 °C, the
refilling of AdBlue may not be
detected by the system. In this
event, park the vehicle in a space
with a higher ambient temperature
until AdBlue is liquefied.Notice
When unscrewing the protective cap
from the filler neck, ammonia fumes
may emerge. Do not inhale as the fumes have a pungent smell. The
fumes are not harmful by inhalation.
The vehicle must be parked on a level surface.
The filler neck for AdBlue is located
behind the fuel filler flap.
The fuel filler flap is located at right rear side of the vehicle.
The fuel filler flap can only be opened
if the vehicle is unlocked.
1. Remove key from ignition lock.
2. Close all doors to avoid ammonia fumes entering the interior of the
vehicle.
3. Release the fuel filler flap by pushing the flap 3 215.
4. Unscrew protective cap from the
filler neck.
5. Open AdBlue canister.
6. Mount one end of the hose on the
canister and screw the other end
on the filler neck.
7. Lift the canister until it is empty. 8. Unscrew the hose from the filler neck.
9. Mount the protective cap and turn
clockwise until it engages.
Notice
Dispose of AdBlue canister and
hose according to environmental
requirements.