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104Instruments and controls● If a warning message appears inthe Driver Information Centre.
● If the parking assist detects an object.
● If unintended lane change occurs.
● If the exhaust filter has reached the maximum filling level.
When the vehicle is parked and/or the driver's door is opened
● With exterior lights on.
During an Autostop ● If the driver's door is opened.
Battery voltage When the vehicle battery voltage is
running low, a warning message will
appear in the Driver Information
Centre.1. Switch off immediately any electrical consumers which are
not required for a safe ride, e.g.
seat heating, heated rear window or other main consumers.
2. Charge the vehicle battery by driving continuously for a while or
by using a charging device.
The warning message will disappear
after the engine has been started
twice consecutively without a voltage
drop.
If the vehicle battery cannot be
recharged, have the cause of the fault
remedied by a workshop.Vehicle personalisation
The vehicle's behaviour can be
personalised by changing the settings
in the Info-Display.
Some of the personal settings for
different drivers can be memorised individually for each vehicle key.
Memorised settings 3 23.
Depending on vehicle equipment and
country-specific regulations, some of
the functions described below may
not be available.
Some functions are only displayed or
active when the engine is running.
Personal settings in the
Graphic-Info-Display
CD 400plus/CD 400/CD 300
Page 129 of 261

Climate control127Climate controlClimate control systems.............127
Heating and ventilation system 127
Air conditioning system ...........128
Electronic climate control system .................................... 130
Auxiliary heater ........................134
Air vents ..................................... 135
Adjustable air vents .................135
Fixed air vents ......................... 135
Maintenance .............................. 135
Air intake ................................. 135
Air conditioning regular operation ................................ 136
Service .................................... 136Climate control systems
Heating and ventilation system
Controls for: ● temperature
● air distribution
● fan speed
● demisting and defrosting
Heated rear window Ü 3 35.
Temperature
red:warmblue:coldHeating will not be fully effective until
the engine has reached normal
operating temperature.
Air distributions:to windscreen and front door
windowsM:to head area via adjustable air
ventsK:to foot well and windscreen
All combinations are possible.
Fan speed
Adjust the air flow by switching the fan to the desired speed.
Page 130 of 261
128Climate controlDemisting and defrosting
●Press V: fan automatically
switches to higher speed, the air
distribution is directed towards
the windscreen.
● Set temperature control to warmest level.
● Switch on heated rear window Ü.
● Open side air vents as required and direct them towards the doorwindows.
Air conditioning system
In addition to the heating and
ventilation system, the air
conditioning system has controls for:
n:cooling4:air recirculation
Heated seats ß 3 55, Heated
steering wheel * 3 79.
Cooling n
Press n to switch on cooling. The
LED in the button illuminates to
indicate activation. Cooling is only
functional when the engine is running and climate control fan is switched on.
Press n again to switch off cooling.
The air conditioning system cools and
dehumidifies (dries) as soon as the
outside temperature is slightly above
the freezing point. Therefore
condensation may form and drip from under the vehicle.
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132Climate control
If the minimum temperature Lo is set,
the climate control system runs at
maximum cooling, if cooling n is
switched on.
If the maximum temperature Hi is set,
the climate control system runs at
maximum heating.
Note
If n is switched on, reducing the set
cabin temperature can cause the
engine to restart from an Autostop or inhibit an Autostop.
Stop-start system 3 140.
Demisting and defrosting the
windows V
●
Press V. 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 heated rear window Ü.
● To return to previous mode: press V. To return to automatic
mode: press AUTO.
Setting of automatic rear window heating can be changed in the
Settings menu in the Info-Display.
Vehicle personalisation 3 104.
Note
If V is pressed while the engine is
running, an Autostop will be inhibited
until V is pressed again.
If s is pressed with the fan switched
on and the engine running, an
Autostop will be inhibited until s is
pressed again or until the fan is
switched off.
If V is pressed while the engine is
in an Autostop, the engine will restart automatically.
If s is pressed with the fan switched
on while the engine is in an
Autostop, the engine will restart
automatically.
Stop-start system 3 140.
Manual settings Climate control system settings can
be changed by activating the buttons
and rotary knobs as follows.
Changing a setting will deactivate the automatic mode.
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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
Note
Refrigerant R-134a contains
fluorinated greenhouse gases.
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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.
The stop-start system will be disabled
on inclines of 12% or more.
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 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 3 130.
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 electrical
features such as auxiliary electric
heater or rear window heating are
disabled or switched 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 Depress the clutch pedal to restart the
engine.
Page 204 of 261
202Vehicle careNo.Circuit1Engine control module2Lambda sensor3Fuel injection, ignition system4Fuel injection, ignition system5–6Mirror heating7Fan control8Lambda sensor, engine cooling9Rear window sensor10Vehicle battery sensor11Trunk release12Adaptive forward lighting, auto‐
matic light control13ABS Valves14–15Engine control module16Starter17Transmission control moduleNo.Circuit18Heated 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 brake30ABS pump31–32Airbag33Adaptive forward lighting, auto‐
matic light control34Exhaust gas recirculation
Page 205 of 261
Vehicle care203No.Circuit35Power windows, rain sensor,
exterior mirror36Climate control37–38Vacuum pump39Fuel system control module40Windscreen washer system41Right high beam (Halogen)42Radiator fan43Windscreen wiper44–45Radiator fan46–47Horn48Radiator fan49Fuel pump50Headlamp levelling, adaptive
forward lightingNo.Circuit51–52Auxiliary 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, malfunctions may occur.
Instrument panel fuse box
In left-hand drive vehicles, the fuse
box is behind the storage
compartment in the instrument panel.
Open the compartment and push it to the left to unlock. Fold the
compartment down and remove it.