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Driving and operating135
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 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 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 the eco button.
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.
■ Set the lever in neutral.
■ Release the clutch pedal.
The engine will be switched off while
the ignition stays on.
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136Driving and operating
An Autostop is indicated by the
needle at the AUTOSTOP position in
the tachometer.
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.
■ 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 3 125.
Immediately after motorway driving
an Autostop may be inhibited.
New vehicle running-in 3 133.
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 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.
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Driving and operating137
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 (DIC).
Control indicator - 3 90.
Restart of the engine by the
stop-start system The selector lever has to 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
DIC.
If an electrical accessory, e.g. a
portable CD player, is connected to
the power outlet, a brief power drop during 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.
Activate the manual parking
brake without pressing the
release button. Apply as firmly
as possible on a downhill slope
or uphill slope. Depress foot
brake 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 90.
■ 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
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138Driving and operatingkey. Turn the front wheels
towards the kerb.
■ Close the windows and the soft top.
■ Remove the ignition key. 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 switchedoff 3 185.
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.
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
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
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Driving and operating139
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 the cleaning of the filter is required
and if previous driving conditions did
not enable automatic cleaning, it will
be indicated by control indicator %.
Simultaneously Diesel partic. filter is
full continue driving appears in the
Driver Information Centre (DIC).
% illuminates when diesel particle
filter is full. Start cleaning process as
soon as possible.
% 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.
If additionally a message appears in
the DIC that cleaning is not possible,
seek the assistance of a workshop.Caution
If the cleaning process is
interrupted, there is a risk of
provoking severe engine damage.
Cleaning takes place quickest at high engine speeds and loads.
The control indicator % extinguishes
as soon as the self-cleaning
operation is complete.
Catalytic converter
The catalytic converter reduces the
amount of harmful substances in the
exhaust gases.Caution
Fuel grades other than those listed on pages 3 175, 3 236 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
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140Driving and operating
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 the DEF used is AdBlue Ⓡ 1)
. 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.
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 (DIC).
A volume of at least 5 litres of AdBlue
must be refilled as soon as possible.
Driving is possible without any
restrictions.
If AdBlue is not refilled within a certain distance, further level warnings are
displayed in the DIC 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 DIC:
■ AdBlue Low Refill Now
■ Engine Restart Prevented in 560
miles
Additionally, the control indicator Y
flashes continuously and a warning
chime sounds four times every
three minutes.1) Registered trademark of the Verband der Automobilindustrie e.V. (VDA).
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Driving and operating141
Before the prevention of the engine
restart is activated, the following
warning messages:
■ AdBlue Empty Refill Now
■ Engine Will Not Restart
are alternately displayed in the DIC.
Additionally the control indicator Y
flashes continuously and a warning
chime sounds four times every
three minutes.
After the prevention of the 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 (DIC).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.
Notice
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.
If AdBlue must be refilled at
temperatures below -11 °C, the
refilling of AdBlue may not be
detected by the system. In this case, 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.
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142Driving and operating
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. Pull fuel filler flap at the recess and open 3 175.
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.
Exchanging AdBlue
If less than 5 litres of AdBlue have
been refilled during the last 2 years,
the remaining fluid should be
exchanged since AdBlue has a
limited durability.Caution
Disregard could lead to damage to
the selective catalytic reduction
system.
Automatic transmission
The automatic transmission permits
automatic gearshifting (automatic
mode) or manual gearshifting
(manual mode).
Manual shifting is possible in manual
mode by tapping the selector lever
3 144.
Transmission display
The mode or selected gear is shown
in the transmission display.