2012 MERCEDES-BENZ C-Class SEDAN ignition

iThe cooling with air dehumidification
function uses refrigerant R134a. This
coolant does not contain
chlorofluorocarbons, and therefore does
not damage the ozone layer.
Activating/deactivatingXTo activate: press the ¿ button.
The indicator lamp in the ¿ button lights
up.XTo switch off: press the ¿ button.
The indicator lamp in the ¿ button goes
out. The cooling with air dehumidification
function has a delayed switch-off feature.
Problems with the cooling with air
dehumidification function
When you press the ¿ button, the
indicator lamp in the button flashes three
times or remains off. You can no longer switch
on the cooling with air dehumidification
function.
XConsult a qualified specialist workshop.
Setting climate control to automatic
GWARNING
If you switch off the cooling function, the
vehicle will not be cooled when weather
conditions are warm. The windows can fog up
more quickly. Window fogging may impair
visibility and endanger you and others.
In automatic mode, the set temperature is
maintained automatically at a constant level.
The system automatically regulates the
temperature of the dispensed air, the airflow
and the air distribution.
Automatic mode will achieve optimal
operation if cooling with air dehumidification
is also activated. If desired, cooling with air
dehumidification can be deactivated.
XTurn the SmartKey to position 2 in the
ignition lock.XSet the desired temperature.XTo activate: press the à button.
The indicator lamp in the à button lights
up. Automatic air distribution and airflow
are activated.
i 3-zone automatic climate control: when
automatic mode is activated, you can
select a climate mode setting
( Y page 127).
XTo switch off: press the _ button.
or
XPress the K or I button.
The indicator lamp in the à button goes
out. Automatic air distribution and airflow
are deactivated.
Adjusting the climate mode settings
(AIR FLOW)
This function is only available with 3-zone
automatic climate control.
The climate mode settings are especially
effective at high temperatures.
You can select the following climate mode
settings in automatic mode:
FOCUShigh airflow that is set slightly
coolerMEDIUMmedium airflow, standard settingDIFFUSElow airflow that is set slightly
warmer and with less draftXTurn the SmartKey to position 2 in the
ignition lock.XPress the à button.XPress the ñ button repeatedly until the
desired climate mode appears in the
display.Operating the climate control system127Climate controlZ

Setting the temperature
Dual-zone automatic climate control
Different temperatures can be set for the
driver's and front-passenger sides.
XTurn the SmartKey to position 2 in the
ignition lock.XTo increase/reduce: turn controls : and
B clockwise or counter-clockwise
( Y page 123).
Only change the temperature setting in
small increments. Start at 72 ‡ (22 †).
3-zone automatic climate control
Automatic climate control climate zones
You can select different temperature settings
for the driver's and front-passenger sides as
well as for the rear compartment.
XTurn the SmartKey to position 2 in the
ignition lock.XTo increase/reduce the temperature in
the front: turn controls : and B
clockwise or counter-clockwise
( Y page 125).
Only change the temperature setting in
small increments. Start at 72 ‡ (22 †).XTo increase/reduce the temperature in
the rear compartment using the front
control panel: press the á button.
The indicator lamp in the á button goes
out.XTurn control : clockwise or counter-
clockwise ( Y page 125).
Only change the temperature setting in
small increments. Start at 72 ‡ (22 †).XTo increase/reduce the temperature in
the rear compartment using the rear
control panel: press the r or s
button on the rear control panel.
Only change the temperature setting in
small increments. Start at 72 ‡ (22 †).
i If you leave the vehicle parked for longer
than 30 minutes, the temperature setting
for the rear compartment then switches
back to 22 ‡.
Setting the air distribution
Air distribution settings
PDirects air through the center and side
air ventsODirects the airflow through the
footwell air ventsSDirects air through the center, side and
footwell vents¯Directs air through the defroster ventsbDirects the airflow through the
defroster, center and side air vents 12aDirects air through the defroster and
footwell vents_Directs the airflow through the
defroster, center and side air vents as
well as the footwell air vents 12
i
Regardless of the air distribution setting,
airflow is always directed through the side
air vents.. The side air vents can only be
closed when the controls on the side air
vents are turned downwards.
12 Canada only.128Operating the climate control systemClimate control

XTurn the SmartKey to position 2 in the
ignition lock.XPress the _ button repeatedly until the
desired symbol appears in the display.
The indicator lamp in the à button goes
out. Automatic control is deactivated and
the air distribution is controlled according
to the selected setting.
Setting the airflow
XTurn the SmartKey to position 2 in the
ignition lock.XTo increase/reduce: press the K or
I button.
i
You can use automatic climate control to
set the airflow in the rear compartment
separately.
Switching the ZONE function on/off
This function is only available in vehicles for
Canada.
XTo switch on: press the á button.
The indicator lamp in the á button lights
up.
Dual-zone automatic climate control: the
temperature setting for the driver's side is
not adopted for the front-passenger side.
3-zone automatic climate control: the
temperature setting for the driver's side is
not adopted for the front-passenger side
and the rear compartment.
When the buttons for temperature, airflow or
air distribution are activated, the temperature
setting for the driver's side is not adopted for
the other climate control zones.
XTo switch off: press the á button.
The indicator lamp in the á button goes
out.
Dual-zone automatic climate control: the
temperature setting for the driver's side is
adopted for the front-passenger side.3-zone automatic climate control: the
temperature setting for the driver's side is
adopted for the front-passenger side and
the rear compartment.
Defrosting the windshield
You can use this function to defrost the
windshield or to defrost the inside of the
windshield and the side windows.
i You should only select the defrosting
function until the windshield is clear again.
XTurn the SmartKey to position 2 in the
ignition lock.XTo activate: press the ¬ button.
The indicator lamp in the ¬ button lights
up.
The climate control system switches to the
following functions:
R cooling with air dehumidification on
R high airflow 13
R high temperature 13
R air distribution to the windshield and
front side windows
R air-recirculation mode offXTo switch off: press the ¬ button.
The indicator lamp in the ¬ button goes
out. The previously selected settings come
into effect again. The cooling with air
dehumidification function remains on. Air-
recirculation mode remains deactivated.
or
XPress the à button.
The indicator lamp in the ¬ button goes
out. Airflow and air distribution are set to
automatic mode.
or
XTurn temperature control : or B
clockwise or counter-clockwise
( Y page 123), ( Y page 125).13
Depending on the outside temperature.Operating the climate control system129Climate controlZ

orXPress the K or I button.
MAX COOL maximum cooling
The MAX COOL function is only available in
vehicles for the USA.
MAX COOL is only operational when the
engine is running.
When you activate MAX COOL, climate
control switches to the following functions:
R maximum cooling
R maximum airflow
R air-recirculation mode on
XTo activate: press the Ù button.
The indicator lamp in the button lights up.XTo deactivate: press the Ù button
again.
The indicator lamp goes out. The previously
selected settings come into effect again.
Defrosting the windows
Windows fogged up on the inside
XActivate the cooling with air
dehumidification function ¿.XActivate automatic mode Ã.XIf the windows continue to fog up, activate
the defrosting function ( Y page 129).
i
You should only select this setting until
the windshield is clear again.
Windows fogged up on the outside
XSwitch on the windshield wipers.XPress the _ button repeatedly until the
O or P symbol appears in the
display.
i You should only select this setting until
the windshield is clear again.
Rear window defroster
Activating/deactivatingGWARNING
Any accumulation of snow and ice should be
removed from the rear window before driving.
Visibility could otherwise be impaired,
endangering you and others.
The rear window defroster has a high current
draw. You should therefore switch it off as
soon as the window is clear as it only switches
off automatically after several minutes.
If the battery voltage is too low, the rear
window defroster may switch off.
XTurn the SmartKey to position 2 in the
ignition lock.XPress the ¤ button.
The indicator lamp in the ¤ button lights
up or goes out.
Problems with the rear window
defroster
The rear window defroster has deactivated
itself prematurely or cannot be activated.
XSwitch off any consumers that are not
required, e.g. reading lamps or interior
lighting.
When the battery is sufficiently charged,
the rear window defroster is activated
again automatically.
Activating/deactivating air-
recirculation mode
You can deactivate the flow of fresh air if
unpleasant odors are entering the vehicle
from outside. The air already inside the
vehicle will then be recirculated.
The operation of air-recirculation mode is the
same for all control panels.
GWARNING
Fogged windows impair visibility,
endangering you and others. If the windows
130Operating the climate control systemClimate control

begin to fog on the inside, switching off the
air recirculation mode immediately should
clear interior window fogging. If interior
window fogging persists, make sure the air
conditioning is activated, or press the ¬
button.XTurn the SmartKey to position 2 in the
ignition lock.XTo activate: press the g button.
The indicator lamp in the g button lights
up.
i In the event of high pollution levels 14
or at
high outside temperatures, air-
recirculation mode is automatically
activated. When air-recirculation mode is
activated automatically, the indicator lamp
in the g button is not lit.
Outside air is added after about 30
minutes.
XTo switch off: press the g button.
The indicator lamp in the g button goes
out.
i Air-recirculation mode deactivates
automatically:
R after approximately five minutes if
outside temperatures are less than about
41 ‡ (5 †)
R after approximately five minutes if
cooling with air dehumidification is
deactivated
R after approximately 30 minutes if outside
temperatures are over about
41 ‡ (5 †)
Activating/deactivating the residual
heat function
The residual heat function is only available in
vehicles for Canada with automatic climate
control.
It is possible to make use of the residual heat
of the engine to continue heating the
stationary vehicle for up to 30 minutes after
the engine has been switched off. The heating
time depends on the temperature that has
been set.
i The blower will run at a low speed
regardless of the airflow setting.
i If you activate the residual heat function
at high temperatures, only the ventilation
will be activated. The blower runs at
medium speed.XTurn the SmartKey to position 0 in the
ignition lock or remove it.XTo activate: press the Ì button.
The indicator lamp in the Ì button lights
up.XTo switch off: press the Ì button.
The indicator lamp in the Ì button goes
out.
i Residual heat is deactivated
automatically:
R after about 30 minutes
R when the ignition is switched on
R if the battery voltage drops
R if the coolant temperature is too low
Setting the air vents
Important safety notes
GWARNING
When operating the climate control, the air
that enters the passenger compartment
through the air vents can be very hot or very
cold (depending on the set temperature). This
could cause burns or frostbite to unprotected
skin in the immediate area of the air vents.
Always keep sufficient distance between
unprotected parts of the body and the air
vents. If necessary, use the air distribution
adjustment to direct the air to air vents in the
14 Automatic climate control only.Setting the air vents131Climate controlZ

GWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
GWARNING
It is dangerous to shift the automatic
transmission out of parking position P or
neutral position N if the engine speed is
higher than idle speed. If your foot is not firmly
on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only shift the automatic transmission to
the desired drive position when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. You could otherwise damage the
drive train.
! AMG vehicles: at low engine oil
temperatures (below 68 ‡ (+20 †), the
maximum engine speed is restricted in
order to protect the engine. To protect the
engine and maintain smooth engine
operation, avoid driving at full throttle when
the engine is cold.
SmartKey positions
SmartKeygTo remove the SmartKeyVehicles with automatic transmission:
shift the transmission to position P1Power supply for some consumers, such
as the windshield wipers2Ignition (power supply for all consumers)
and drive position3To start the engine
If the SmartKey is in position 0 in the ignition
lock for an extended period of time, it can no
longer be turned in the ignition lock. The
steering is then locked. To unlock, remove the
SmartKey and reinsert it into the ignition lock.
The steering is locked when you remove the
SmartKey from the ignition lock.
i The SmartKey can be turned in the
ignition lock even if it is not the correct
SmartKey for the vehicle. The ignition is not
switched on. The engine cannot be started.
KEYLESS-GO
General information
Vehicles with KEYLESS-GO are equipped with
a SmartKey featuring an integrated KEYLESS-
GO function and a detachable Start/Stop
button.
The Start/Stop button must be inserted into
the ignition lock and the SmartKey must be in
the vehicle.
Driving137Driving and parkingZ

Pressing the Start/Stop button several times
in succession corresponds to the different
SmartKey positions in the ignition lock. This
is only the case if you are not depressing the
brake pedal.
If you depress the brake pedal and press the
Start/Stop button, the engine starts
immediately.
The Start/Stop button can be removed from
the ignition lock. Then, you can insert the
SmartKey into the ignition lock.
i You do not have to remove the Start/Stop
button from the ignition lock when you
leave the vehicle. However, you should
always take the SmartKey with you when
leaving the vehicle. The vehicle can be
started with the Start/Stop button if the
SmartKey is in the vehicle.:Start/Stop button;Ignition lockXInsert Start/Stop button : into ignition
lock ;.
i
When you insert Start/Stop button :
into ignition lock ;, the system requires a
detection time of approximately two
seconds before you can use Start/Stop
button :.
Start/Stop button
=USA only?Canada onlyXPosition 0: if Start/Stop button : has not
yet been pressed, this corresponds to the
SmartKey being removed from the ignition.XPosition 1: press Start/Stop button :.
You can now activate the windshield
wipers, for example.
i If you then open the driver's door when in
this position, the power supply is
deactivated.
XPosition 2 (ignition): press Start/Stop
button : twice.
i
If you press Start/Stop button : once
when in this position and the driver's door
is open, the power supply is deactivated
again.
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. If an indicator lamp does not go out after
the engine is started or if it lights up while the
vehicle is in motion, see ( Y page 241).
Starting the engine
Important safety notes
GWARNING
Inhalation of exhaust gas is hazardous to your
health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and possible death.
138DrivingDriving and parking

Do not run the engine in confined areas (such
as a garage) which are not properly ventilated.
If you think that exhaust gas fumes are
entering the vehicle while driving, have the
cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one
window fully open at all times.
! Do not depress the accelerator pedal
when starting the engine.
i The catalytic converter preheats for up to
30 seconds after a cold start. The sound of
the engine may change during this time.
Automatic transmissionXShift the transmission to position P.
The transmission position display in the
multifunction display shows P.
i
You can also start the engine when the
transmission is in position N.
Starting procedure with the SmartKey
i To start the engine using the SmartKey
instead of KEYLESS-GO, pull the Start/
Stop button out of the ignition lock.
XTurn the SmartKey to position 3 in the
ignition lock (Y page 137) and release it as
soon as the engine is running.
Using KEYLESS-GO to start the engine
GWARNING
As long as the SmartKey is in your vehicle, the
vehicle can be started. Therefore, never leave
children unattended in the vehicle, as they
could otherwise accidentally start the engine.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Do
not leave children unattended in the vehicle,
or with access to an unlocked vehicle. A
child's unsupervised access to a vehicle could
result in an accident and/or serious personal
injury.
i The Start/Stop button can be used to
start the vehicle without inserting the
SmartKey into the ignition lock. The Start/
Stop button must be inserted into the
ignition lock and the SmartKey must be in
the vehicle.XDepress the brake pedal and keep it
depressed.XPress the Start/Stop button ( Y page 137)
once.
The engine starts.
Pulling away
Automatic transmission
GWARNING
It is dangerous to shift the automatic
transmission out of parking position P or
neutral position N if the engine speed is
higher than idle speed. If your foot is not firmly
on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.
i It is only possible to shift the transmission
from position P to the desired position if
you depress the brake pedal. Only then is
the selector lever lock released.
XDepress the brake pedal and keep it
depressed.XShift the transmission to position D or R.XRelease the parking brake ( Y page 154).XRelease the brake pedal.XCarefully depress the accelerator pedal.
!
If a warning tone sounds and the
Release Park. Brake message appears
in the multifunction display, the parking
brake is still applied. Release the parking
brake.
Driving139Driving and parkingZ