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146Climate controlTemperature preselection
Set the preselected temperatures
separately for driver and front
passenger to the desired value using
the left and right control dials. The
knob on the passenger side changes
the temperature for the passenger
side. The knob on the driver's side
changes the temperature for the
driver's side or for both sides
depending on activation of
synchronisation SYNC.
Recommended temperature is 22 °C .
Temperature is indicated in displays
beside the control dials and as pop-
up in the Info-Display.
If the minimum temperature Lo is set,
the climate control system runs at maximum cooling, if cooling A/C is
switched on.
If the maximum temperature Hi is set,
the climate control system runs at maximum heating.
Note
If A/C is switched on, reducing the
set cabin temperature can cause the engine to restart from an Autostop or
inhibit an Autostop.
Stop-start system 3 157.
Dual zone temperature
synchronisation SYNC
Press Climate to enter the menu.
Touch SYNC to link passenger side
temperature setting to the driver side.
When passenger side control dial will be adjusted, synchronisation is
deactivated.Air conditioning A/C
Press Climate to enter the menu and
follow the touch button to switch air
conditioning A/C ON or A/C OFF.
Cooling is only functional when the
engine is running and climate control
fan is switched on.
The air conditioning system cools and
dehumidifies (dries) when outside
temperature is above a specific level. Therefore condensation may form
and drip from under the vehicle.
If no cooling or drying is required,
switch off the cooling system for fuel
saving reasons.
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Climate control149Basic 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 3 117.
Heated rear window and exterior mirrors b
3 37
Heated windscreen ,
3 38.
Heated seats ß
3 48.
Ventilated seats A
3 49Auxiliary 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 153 of 303
Climate control151Air 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 156 of 303

154Driving and operatingPower button
Electronic key must be inside the
vehicle.
Accessory power mode
Press Engine Start/Stop once without
operating clutch or brake pedal. The yellow LED in the button illuminates.
Steering wheel lock is released and
some electrical functions are
operable, ignition is off.Ignition on power mode
Press and hold Engine Start/Stop for
six seconds without operating clutch
or brake pedal. The green LED in the button illuminates, diesel engine ispreheating. Control indicators
illuminate and most electrical
functions are operable.Engine start
Press Engine Start/Stop briefly while:
● manual transmission: operating clutch pedal,
● automatic transmission: operating brake pedal with
selector lever in P or N.
Starting the engine 3 155.Ignition off
Press Engine Start/Stop briefly when
Autostop is activated or when engine is running and vehicle is stationary.
Automatic transmission: apply the
parking brake and engage P.
Press Engine Start/Stop briefly
without operating clutch or brake pedal when in ignition on power
mode.
Some functions remain active until
driver's door is opened, provided the
ignition was on previously.Emergency engine shut off during
driving
Press Engine Start/Stop for more
than two seconds or press twice
briefly within five seconds 3 155.
Steering wheel lock The steering wheel lock activates
automatically when:
● The vehicle is stationary.
● The ignition has been switched off.
● The driver's door is opened.
To release steering wheel lock, open
and close driver's door and switch on accessory mode or start the engine
directly.9 Warning
If the vehicle battery is discharged,
the vehicle must not be towed,
tow-started or jump-started as the
steering wheel lock cannot be
disengaged.
Page 159 of 303

Driving and operating157Stop-start systemThe 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.
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 Ò. Deactivation
is indicated when the LED in the
button illuminates.
AutostopVehicles with manual transmission
An Autostop can be activated at a
standstill or at a low speed up to
14 km/h.
Activate a conventional Autostop as
follows:
● Depress the clutch pedal.
● Set the lever to neutral.
● Release the clutch pedal.
The engine will be switched off while
the ignition stays on.Indication
An Autostop is indicated by the
needle at the AUTOSTOP position in
the tachometer.
After restarting, the idle speed is
indicated.
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.
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168Driving and operating● Special programmesautomatically adapt the shiftingpoints when driving up inclines or
down hills.
● In snowy or icy conditions or on other slippery surfaces, the
electronic transmission control
enables the driver to manually
select first, second or third gear
for starting off.
Kickdown
Pressing down the accelerator pedal
beyond the kickdown detent will lead
to maximum acceleration even in manual mode. The transmission
shifts to a lower gear depending on
engine speed and shifts to a higher
gear at high engine revolutions.
Overheat protection
In the event of transmission-
overheating due to high outside
temperatures or sporty driving style,
the torque and the maximum speed of the engine can be temporarily
reduced.Fault
In the event of a fault a vehicle
message is displayed in the Driver
Information Centre. Vehicle
messages 3 115.
6-gear automatic transmission:
electronic transmission control
enables only fourth gear; 8-gear
automatic transmission: electronic
transmission control enables only
third gear. The transmission no
longer shifts automatically.
Have the cause of the fault remedied by a workshop.
Interruption of power supply
In the event of an interruption of
power supply, the selector lever
cannot be moved out of the P
position. The ignition key cannot be
removed from the ignition switch.
If the vehicle battery is discharged,
start the vehicle using jump leads
3 264.
If the vehicle battery is not the cause
of the fault, release the selector lever.
1. Apply parking brake.
2. Release the selector lever trim from the centre console. Poke
with a finger into the leather socket below the selector lever
and push the trim upwards.
Rotate trim to the left.
Page 224 of 303

222Driving and operatingCaution
Use of fuel that does not comply toEN 228 or E DIN 51626-1 or
equivalent can lead to deposits or
engine damage.
Caution
Use of fuel with a lower octane
rating than the lowest possible
rating could lead to uncontrolled combustion and engine damage.
The engine specific requirements
regarding octane rating are given in
the engine data overview 3 280. A
country-specific label at the fuel filler
flap can supersede the requirement.
Fuel for diesel engines Only use diesel fuel that complies
with EN 590.
In countries outside the European
Union use Euro-Diesel fuel with a
sulfur concentration below 50 ppm.
Caution
Use of fuel that does not comply to EN 590 or similar can lead to
engine powerloss, increased wear
or engine damage.
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.
Refuelling
9 Danger
Before refuelling, switch off
ignition and any external heaters
with combustion chambers.
Follow the operating and safety
instructions of the filling station
when refuelling.
9 Danger
Fuel is flammable and explosive.
No smoking. No naked flames or
sparks.
If you can smell fuel in your
vehicle, have the cause of this
remedied immediately by a
workshop.
Caution
In case of misfuelling, do not
switch on ignition.
Fuel filler flap is located at right rear
side of vehicle.
Page 249 of 303
Vehicle care247No.Circuit52–53–54–55–56Starter57–58–59Left headlight (LED)60Cooling fan61–62–63–64–65Climate control66–67–68–No.Circuit69Right high beam (Halogen)/
Right headlight (LED)70Left high beam (Halogen)71–72Starter73–74Transmission control module75Engine control module76Exhaust reduction system77–78Horn79Washer system80–81Engine control module82–83Ignition coil84Ignition coil85PowertrainNo.Circuit86–87Diesel fuel heating88Air shutter89–90–91–92After boil pump93Electronic key system94–95Coolant pump96Diesel fuel heating97–98–99Coolant pump
After having changed defective fuses,
close the fuse box cover and press
until it engages.
If the fuse box cover is not closed
correctly, malfunction may occur.