118Driving and operatingTurbo 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.
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.On vehicles with manual
transmission, the engine is started 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.
DeactivationDeactivate the stop-start system
manually by pressing eco. The
deactivation is indicated when the
LED in the button extinguishes.
AutostopVehicles with manual transmission:
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.
Driving and operating119Indication
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.
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 sufficientlycharged 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 3 109.
Immediately after motorway driving,
an Autostop may be inhibited.New vehicle running-in 3 116.
Vehicle battery discharge protection To ensure reliable engine restarts,
several vehicle battery discharge
protection features are implemented
as part of the stop-start system.
Power saving measures
During an Autostop, several electrical
features, e.g. the 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 driverVehicles with manual transmission:
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 76.
120Driving and operatingRestart of the engine by the stop-
start system
The selector lever must be in neutralto 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, awarning 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 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 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.
● Switch off the engine.
● If the vehicle is on a level surface or uphill slope, engage
first gear 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
before removing the ignition
key. Turn the front wheels
towards the kerb.
● Close the windows and the sunroof.
● Remove the ignition key from the ignition switch. Turn the
steering wheel until the
steering wheel lock is felt to
engage.
● Lock the vehicle.
● The engine cooling fans may run
after the engine has been
switched off 3 150.
Driving and operating121Caution
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.
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.
Exhaust filter
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 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.
System requires manual cleaning
process
Under certain driving 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
122Driving and operatingindicated by illumination of % and a
warning message in the Driver
Information Centre.
% 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 manual 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 takes place quickest 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 anyreasons, control indicator Z
illuminates. 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 3 142, 3 203 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.
Driving and operating123Manual transmission
To engage reverse, depress the
clutch pedal and press the release button on the selector lever and
engage the gear.
If the gear does not engage, set the
lever to neutral, release the clutch
pedal and depress again; then repeat
gear selection.
Do not slip the clutch unnecessarily.
When operating, depress the clutch
pedal completely. Do not use the
pedal as a foot rest.
Caution
It is not advisable to drive with the hand resting on the selector lever.
Gear shift indication 3 77.
Stop-start system 3 118.
Brakes
The brake system comprises two
independent brake circuits.
If a brake circuit fails, the vehicle can
still be braked using the other brake
circuit. However, braking effect is
achieved only when the brake pedal
is depressed firmly. Considerably
more force is needed for this. The
braking distance is extended. Seek
the assistance of a workshop before
continuing the journey.
When the engine is not running, the
support of the brake servo unit
disappears once the brake pedal has been depressed once or twice.
Braking effect is not reduced, but
braking requires significantly greater
force. It is especially important to bear this in mind when being towed.
Control indicator R 3 76.
Antilock brake system
Antilock brake system (ABS)
prevents the wheels from locking.
Driving and operating125To reduce the operating forces ofthe parking brake, depress the
brake pedal at the same time.
Control indicator R 3 76.
Brake assist If the brake pedal is depressed
quickly and forcefully, maximum
brake force is automatically applied
(full braking).
Maintain steady pressure on the
brake pedal for as long as full braking
is required. Maximum brake force is
automatically reduced when the
brake pedal is released.
Hill start assist The system helps prevent unintendedmovement when driving away on
inclines.
When releasing the brake pedal after
stopping on an incline, the brakes
remain on for a further 2 seconds. The brakes release automatically as soon
as the vehicle begins to accelerate or the 2 seconds holding time is over.
The hill start assist is not active during
an Autostop.Ride control systems
Traction Control system
The Traction Control system (TC) is a component of the Electronic Stability
Control (ESC).
TC improves driving stability when
necessary, regardless of the type of
road surface or tyre grip, by
preventing the drive wheels from
spinning.
As soon as the drive wheels starts to
spin, engine output is reduced and
the wheel spinning the most is braked
individually. This considerably
improves the driving stability of the
vehicle on slippery road surfaces.
126Driving and operating
TC is operational after each engine
start as soon as control indicator b
extinguishes.
When TC operates b flashes.
9 Warning
Do not let this special safety
feature tempt you into taking risks
when driving.
Adapt speed to the road
conditions.
Deactivation
TC can be switched off when spinning of drive wheels is required: press b
briefly.
A status message appears in the
Driver Information Centre when TC is
deactivated.
When TC is deactivated, ESC
remains active.
TC is reactivated by pressing b
again. A status message pops up in the Driver Information Centre when
TC is reactivated.
TC is also reactivated the next time
the ignition is switched on.
Fault
If there is a fault in the system the
control indicator b illuminates
continuously and a message or a
warning code appears in the Driver
Information Centre. The system is not
operational.
Have the cause of the fault remedied by a workshop.
Electronic Stability Control
Electronic Stability Control (ESC)
improves driving stability when
necessary, regardless of the type of
road surface or tyre grip.
As soon as the vehicle starts to
swerve (understeer / oversteer),
engine output is reduced and the
wheels are braked individually.
ESC operates in combination with the Traction Control system (TC). It
prevents the drive wheels from
spinning.