Page 138 of 293
136Climate controlAir conditioning regularoperation
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
Notice
Refrigerant R-134a contains
fluorinated greenhouse gases.
Page 141 of 293

Driving and operating139Ignition 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 ten minutes after the ignition is switched off:
● power windows
● sunroof
● power outlets
Power to the Infotainment system will continue to operate for 30 minutes or
until 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.
Do not operate the accelerator pedal.
Diesel engine: turn the key to position 2 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
Starting 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 vehicle battery.
With temperatures below -30 °C the
automatic transmission needs a
warming phase of approx. five
minutes. The selector lever must be
in position P.
Page 143 of 293

Driving and operating141The engine will be switched off whilethe 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 power steering assist may 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 3 130.
Immediately after motorway driving,
an Autostop may be inhibited.
New vehicle running-in 3 138.
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 heated rear window 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.
Page 189 of 293

Driving and operating187Some fuel does not contain sufficient
quantities of additive to keep fuel
injectors and intake valves clean.
To make up for this lack of
detergency, add Fuel System
Treatment PLUS to the fuel tank at
every engine oil change or every
10,000 miles, whichever occurs first.
It is available at your workshop.
Fuels containing oxygenates such as
ethers and ethanol, as well as
reformulated fuel, are available in
some cities. If these fuels comply with
the previously described
specification, then they are
acceptable to use. However, E85
(85% ethanol) and other fuels
containing more than 15% ethanol
must be used only in FlexFuel
vehicles.Caution
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 86.
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
Page 223 of 293
Vehicle care221Engine compartment fusebox
The fuse box is in the front left of the
engine compartment.
Disengage the cover and fold it
upwards until it stops. Remove the
cover vertically upwards.
No.Circuit1Engine control module2Lambda sensor3Fuel injection/Ignition system4Fuel injection/Ignition system5–6Mirror heating/Anti-theft alarm
system7Fan control/Engine control
module/Transmission control
module8Lambda sensor/Engine cooling9Rear window sensor10Vehicle battery sensor11Trunk release12Adaptive forward lighting/Auto‐
matic light control13ABS14Rear window wiper15Engine control module
Page 224 of 293

222Vehicle careNo.Circuit16Starter17Transmission control module18Heated rear window19Front power windows20Rear power windows21Rear electrical centre22Left high beam (Halogen)23Headlamp washer system24Right low beam (Xenon)25Left low beam (Xenon)26Front fog lights27Diesel fuel heating28Start stop system29Electric parking brake30ABS31Adaptive cruise control32AirbagNo.Circuit33Adaptive forward lighting/Auto‐
matic light control34Exhaust gas recirculation35Exterior mirror/Rain sensor36Climate control37Canister vent solenoid38Vacuum pump39Central control module40Windscreen washer/Rear
window washer system41Right high beam (Halogen)42Radiator fan43Windscreen wiper44Windscreen wiper45Radiator fan46–47Horn48Radiator fanNo.Circuit49Fuel pump50Headlamp levelling/Adaptive
forward lighting51Air shutter52Auxiliary heater/Diesel engine53Transmission control module/
Engine control module54Vacuum pump/Instrument
panel cluster/Heating ventila‐
tion/Air conditioning system
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.
Page 227 of 293
Vehicle care225No.Circuit1–2Trailer outlet3Parking assist4–5–6–7Power seat8–9–10–11Trailer module/Trailer socket12Trailer module13Trailer outlet14Rear seat/Electrical folding15–16Interior mirror17Power outletNo.Circuit18–19Steering wheel heating20Sunroof21Heated front seats22–23–24–25–26Deactivated logistic mode27–28–29–30–31Amplifier/Subwoofer32Active damping system/Lane
departure warningVehicle tools
Tools
Vehicles without spare wheel Some tools and the towing eye are
located in a tool box in the load
compartment below the floor cover.
Page 250 of 293

248Vehicle careIf using a vehicle wash, comply with
the vehicle wash manufacturer's
instructions. The windscreen wiper and rear window wiper must be
switched off. Remove antenna and
external accessories such as roof
racks etc.
If you wash your vehicle by hand,
make sure that the insides of the
wheel housings are also thoroughly
rinsed out.
Clean edges and folds on opened
doors and the bonnet as well as the
areas they cover.
Clean bright metal mouldings with a
cleaning solution approved for
aluminium to avoid damages.Caution
Always use a cleaning agent with
a pH value of four to nine.
Do not use cleaning agents on hot surfaces.
Have the door hinges of all doors
greased by a workshop.
Do not clean the engine compartment with a steam-jet or high-pressure jet
cleaner.
On vehicles with emblem touchpad:
when cleaning with a high-pressure
jet cleaner ensure a minimum
distance of 30 cm when working
around the tailgate to prevent
unintended unlocking.
Thoroughly rinse and leather-off the
vehicle. Rinse leather frequently. Use
separate leathers for painted and
glass surfaces: remnants of wax on
the windows will impair vision.
Exterior lights
Headlight and other light covers are
made of plastic. Do not use any
abrasive or caustic agents, do not use
an ice scraper, and do not clean them
dry.
Polishing and waxing
Wax the vehicle regularly (at the
latest when water no longer beads).
Otherwise, the paintwork will dry out.Polishing is necessary only if the paint
has become dull or if solid deposits
have become attached to it.
Paintwork polish with silicone forms a protective film, making waxing
unnecessary.
Plastic body parts must not be treated
with wax or polishing agents.
Windows and windscreen wiper
blades
Use a soft lint-free cloth or chamois
leather together with window cleaner
and insect remover.
When cleaning the rear window from
inside, always wipe in parallel to the
heating element to prevent damage.
For mechanical removal of ice, use a
sharp-edged ice scraper. Press the
scraper firmly against the glass so
that no dirt can get under it and
scratch the glass.
Remove dirt residues from smearing
wiper blades by using a soft cloth and window cleaner. Also make sure to
remove any residues such as wax,
insect residues and similar from the
window.