Page 161 of 343
Climate control159Maintenance
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.
Pollen filter
The pollen filter cleans dust, soot,
pollen and spores from the air
entering the vehicle through the air
intake.
Air 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
Page 162 of 343

160Driving and operatingDriving and operatingDriving hints............................... 160
Starting and operating ...............161
Engine exhaust .......................... 166
Automatic transmission .............. 167
Manual transmission ..................171
Brakes ........................................ 171
Ride control systems .................174
Driver assistance systems .........179
Fuel ............................................ 210
Trailer hitch ................................ 217Driving hints
Control of the vehicleNever coast with engine not
running (except during Autostop)
Many systems will not function in this
situation ( e.g. brake servo unit, power
steering). Driving in this manner is a
danger to yourself and others. All
systems function during an Autostop,
but there will be a controlled reduction
in power steering assist and vehicle
speed is reduced.
Stop-start system 3 163.
Idle boost
If charging of the vehicle battery is
required due to battery condition, the
power output of the generator must
be increased. This will be achieved by
an idle boost which may be audible.
On vehicles with Uplevel-Combi-
Display, a message appears in the
Driver Information Centre.Pedals
To ensure the pedal travel is
uninhibited, there must be no mats in the area of the pedals.
Steering If power steering assist is lost
because the engine stops or due to a
system malfunction, the vehicle can
be steered but may require increased
effort.
Control indicator c 3 116.Caution
Vehicles equipped with hydraulic
power steering:
If the steering wheel is turned until it reaches the end of its travel, and
is held in that position for more
than 15 seconds, damage may
occur to the power steering
system and there may be loss of
power steering assist.
Page 163 of 343

Driving and operating161Starting and operating
New vehicle running-in Do not brake unnecessarily hard for
the first few journeys.
During the first drive, smoke may
occur because of wax and oil
evaporating off the exhaust system.
Park the vehicle in the open for a
while after the first drive and avoid
inhaling the fumes.
During the running-in period fuel and
engine oil consumption may be
higher and the cleaning process of the diesel particle filter may take
place more often. Autostop may be inhibited to allow for charging the
battery.
Diesel particle filter 3 166.Ignition switch positions0=Ignition off1=Steering wheel lock released,
ignition off2=Ignition on, for diesel engine:
preheating3=Starting
Retained power off
The following electronic systems can
work until the driver's door is opened
or at the latest for 10 minutes after the
ignition is switched off:
■ Power windows
■ Sunroof
■ Power outlets
Power to the Infotainment system will continue to operate for 30 minutes oruntil the key is removed from the
ignition switch, regardless of whether
any door will be opened.
Starting the engine
Manual transmission: operate clutch.
Automatic transmission: operate
brake and move the selector lever to
P or N.
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162Driving and operating
Do not operate the accelerator pedal.Diesel engine: turn the key to position2 for preheating until control
indicator ! extinguishes.
Turn the key briefly to position 3 and
release: an automatic procedure
operates the starter with a short delay
as long as the engine is running, see
Automatic Starter Control.
Before restarting or to switch off the
engine, turn the key back to position
0 .
During an Autostop, the engine can
be started by depressing the clutch
pedal.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. 5 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 is released.
Page 165 of 343

Driving and operating163Stop-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 assoon 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.
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.
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.
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164Driving and operating
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
AutostopOtherwise an Autostop will be
inhibited.
Certain settings of the climate control
system may inhibit an Autostop. See
Climate control chapter for more
details 3 153.
Immediately after motorway driving
an Autostop may be inhibited.
New vehicle running-in 3 161.
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 electric
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.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 - 3 114.
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
Page 167 of 343

Driving and operating165
■ 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 electric 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 3 114.
■ 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 ignitionkey. Turn the front wheels
towards the kerb.
■ Close the windows and the sunroof.
■ 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.
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.
Page 168 of 343

166Driving and operatingEngine 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 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 or warning
code 55 appears in the Driver
Information Centre.
% 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 g illuminates additionally,
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.