Page 159 of 329

Climate control157Manual air recirculation n
Press n to activate the air
recirculation mode. The LED in the
button illuminates to indicate
activation.
Press n again to deactivate
recirculation mode.
9 Warning
The exchange of fresh air is
reduced in air recirculation mode.
In operation without cooling the air humidity increases, so the
windows may mist up from inside.
The quality of the passenger
compartment air deteriorates,
which may cause the vehicle
occupants to feel drowsy.
In warm and very humid ambient air conditions, the windscreen may mist
up from outside, when cold air is
directed towards it. If windscreen
mists up from outside, activate
windscreen wiper and deactivate w.
Automatic air recirculation
An air humidity sensor switches
automatically to external air if internal air humidity is too high.
Demisting and defrosting the
windows à
● Press à. The LED in the button
illuminates to indicate activation.
● Temperature and air distribution are set automatically and the fan
runs at high speed.
● Switch on air conditioning A/C ON in Climate setting menu
by pressing Climate, if required.
● Switch on heated rear window b.
Page 160 of 329
158Climate control● Switch on heatedwindscreen , if available.
● To return to previous mode press
à again, to return to automatic
mode press AUTO.
Note
If à is pressed while the engine is
running, an Autostop will be inhibited until à is pressed again.
If à is pressed while the engine is in
an Autostop, the engine will restart
automatically.
Stop-start system 3 167.Deactivation or activation of
Electronic climate control system
ON/OFF
Cooling, fan and automatic mode can
be switched off by pressing ON/OFF.
When the system is deactivated, the
LED in the button ON/OFF is not
illuminated.
Activation by pressing ON/OFF again
or AUTO . The LED in the button
illuminates to indicate activation.
Version with heated
windscreen ,
If the vehicle is equipped with heated
windscreen, button ON/OFF is
replaced by button ,.
Climate control system will then
switched off by button â. Switch on
by pressing (.
Page 161 of 329
Climate control159Basic settingsFollowing settings can be changed in
the Personalisation menu in the
Info-Display:
● fan speed regulation in automatic
mode.
● settings of automatic rear window
heating.
● settings of automatic windscreen
dehumidification
● settings of automatic seat heating
Vehicle personalisation 3 127.
Heated rear window and exterior mirrors b
3 42
Heated windscreen ,
3 42.
Heated seats q
3 54.
Ventilated seats r
3 54Auxiliary heater
Air heater
Quickheat is an electric auxiliary air
heater which automatically warms up
the passenger compartment more
quickly.Air vents
Adjustable air vents At least one air vent must be open
while cooling is on.
Illustration shows centre air vents in
instrument panel.
Page 162 of 329
160Climate control
Illustration shows outer air vents in
instrument panel.
Illustration shows air vents for rear
passenger.
Direct the flow of air by tilting and
swivelling the slats.
To close the vent, swivel the slat
sideways.9 Warning
Do not attach any objects to the
slats of the air vents. Risk of
damage and injury in case of an
accident.
Fixed air vents
Additional air vents are located
beneath the windscreen and door windows and in the foot wells.
Maintenance
Air intake
The air intake in front of the
windscreen in the engine
compartment must be kept clear to
allow air intake. Remove any leaves,
dirt or snow.
Cabin air filter
Change filter regulary for maximum
effect.
Page 163 of 329
Climate control161Air conditioning regular
operation
In order to ensure continuously
efficient performance, cooling must
be operated for a few minutes once a month, irrespective of the weather
and time of year. Operation with
cooling is not possible when the
outside temperature is too low.
Service For optimal cooling performance, it is
recommended to annually check the
climate control system, starting
three years after initial vehicle
registration, including:
● functionality and pressure test
● heating functionality
● leakage check
● check of drive belts
● cleaning of condenser and evaporator drainage
● performance check
● cabin air filter check
Page 170 of 329

168Driving and operatingDuring 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 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.
The stop-start system will be
deactivated on inclines of 12% or
more.
Certain settings of the climate control
system may inhibit an Autostop. See
Climate control chapter for more
details 3 150.
Immediately after motorway driving,
an Autostop may be inhibited.
New vehicle running-in 3 163.
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
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.
Page 171 of 329

Driving and operating169Vehicles with automatic transmissionRelease 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.
● 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 systemrequests 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 3 109.
● 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
switching off ignition. 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 switching off ignition.
Turn the front wheels towards
the kerb.
● Close the windows and the sunroof.
● Switch off ignition with power button. Turn the steering wheel
until the steering wheel lock is
felt to engage.
Page 234 of 329

232Driving and operatingCaution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
This damage would not be
covered by the vehicle warranty.
Some fuels, mainly high octane
racing fuels, can contain an octane
enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use fuels or fuel additives with MMT as they can
reduce spark plug life and affect
emission control system
performance. The malfunction
indicator light Z may
illuminate 3 109. If this occurs, seek
the assistance of a workshop.
Fuel for diesel engines
Only use diesel fuel that complies
with EN 590 and which has a sulphur
concentration of max. 10 ppm.
Fuels with a biodiesel (compliant with
EN 14214) content of max. 7% by
volume may be used (e.g. named
B7).
If travelling in countries outside the
European Union occasional use of Euro-Diesel fuel with a sulphur
concentration below 50 ppm is
possible.
Caution
Frequent usage of diesel fuel
containing more than 15 ppm
sulphur will cause severe engine
damage.
Caution
Use of fuel that does not comply to EN 590 or similar can lead to
engine powerloss, increased wear
or engine damage and may affect
your warranty.
Do not use marine diesel oils, heating
oils, Aquazole and similar diesel-
water emulsions. Diesel fuels must
not be diluted with fuels for petrol
engines.
Low temperature operation At temperatures below 0° C, some
diesel products with biodiesel blends may clog, freeze or gel, which mayaffect the fuel supply system. Starting
and engine operation may not work
properly. Make sure to fill winter
grade diesel fuel at ambient
temperatures below 0°C.
Arctic grade diesel fuel can be used
in extreme cold temperatures below
-20° C. Using this fuel grade in warm
or hot climates is not recommended