2012 MERCEDES-BENZ C-Class SEDAN air condition

1, 2, 3 ...
115 V socket ...................................... 263
12 V socket see Sockets
4ETS
see ETS/4ETS (Electronic
Traction System)
4MATIC (permanent four-wheel
drive) .................................................. 175
4MATIC off-road system ................... 175
A
ABS (Anti-lock Braking System) Display message ............................ 214
Function/notes ................................ 59
Important safety notes ....................59
Warning lamp ................................. 242
Activating/deactivating cooling
with air dehumidification ................. 126
Active Blind Spot Assist Activating/deactivating (on-
board computer) ............................ 205
Function/information ....................187
Active Driving Assistance package . 187
Active Lane Keeping Assist Activating/deactivating (on-
board computer) ............................ 205
Display message ............................ 229
Function/information ....................190
Active light function ......................... 110
Active Light System Display message ............................ 224
Active service system PLUS
see ASSYST PLUS service interval
display
ADAPTIVE BRAKE ................................. 64
Adaptive Highbeam Assist Display message ............................ 225
Function/notes ............................. 110
Switching on/off (on-board
computer) ...................................... 207
Additives (engine oil) ........................ 349
Air bags Display message ............................ 221
Front air bag (driver, front
passenger) ....................................... 39
Important safety notes ....................38
Knee bag .......................................... 40
PASSENGER AIR BAG OFF
indicator lamp .................................. 42
Pelvis air bag ................................... 41
Safety guidelines ............................. 37
Side impact air bag ..........................40
Window curtain air bag ....................42
Air-conditioning system
see Climate control
AIR FLOW ........................................... 127
Air pressure see Tire pressure
Air vents
Glove box ....................................... 132
Important safety notes ..................131
Rear ............................................... 133
Setting ........................................... 131
Setting the center air vents ...........132
Setting the side air vents ...............132
Alarm system
see ATA (Anti-Theft Alarm system)
Alertness Assistant
see ATTENTION ASSIST
AMG menu (on-board computer) ..... 210
Anti-lock Braking System see ABS (Anti-lock Braking System)
Anti-Theft Alarm system
see ATA (Anti-Theft Alarm system)
Ashtray ............................................... 262
Assistance menu (on-board
computer) .......................................... 204
ASSYST PLUS see ASSYST PLUS service interval
display
ATA (Anti-Theft Alarm system)
Activating/deactivating ...................67
Function ........................................... 67
Switching off the alarm ....................67
ATTENTION ASSIST
Activating/deactivating .................205
Display message ............................ 228
Function/notes ............................. 182
Audio menu (on-board computer) .... 201
Audio system see separate operating instructions 4Index

Remote controlGarage door opener .......................270
Reporting safety defects .................... 25
Reserve (fuel tank) see Fuel
Reserve fuel
Display message ............................ 228
Warning lamp ................................. 246
see Fuel
Residual heat (climate control) ........ 131
Restraint system see SRS (Supplemental Restraint
System)
Reverse gear
Engaging (automatic
transmission) ................................. 142
Roadside Assistance (breakdown) .... 22
Roller blind see Roller sunblind
Roller sunblind
Panorama roof with power tilt/
sliding panel ..................................... 88
Rear side windows .........................261
Rear window .................................. 261
Roof carrier ........................................ 259
Roof lining and carpets (cleaning
guidelines) ......................................... 289
Roof load (maximum) ........................ 351
Route see Route guidance (navigation)
Route guidance (navigation) ............ 200
S
Safety Children in the vehicle .....................53
Child restraint systems ....................53
Occupant Classification System
(OCS) ............................................... 42
Overview of occupant safety
systems ........................................... 36
Safety systems
see Driving safety systems
Seat belts
Adjusting the height ......................... 51
Belt force limiters ............................ 52
Cleaning ......................................... 289
Correct usage .................................. 49
Emergency Tensioning Devices ........ 52
Fastening ......................................... 50
Important safety guidelines .............48
Releasing ......................................... 51
Safety guidelines ............................. 37
Special seat belt retractor ...............55
Warning lamp ................................. 239
Warning lamp (function) ................... 51
Seats
Adaptive seat backrests (AMG
vehicles) .......................................... 97
Adjusting (electrically) .....................94
Adjusting (manually and
electrically) ...................................... 94
Adjusting lumbar support ................97
Adjusting the 4-way lumbar
support ............................................ 97
Adjusting the head restraint ............95
Cleaning the cover .........................288
Correct driver's seat position ........... 92
Important safety notes ....................93
Seat heating problem ......................98
Seat ventilation problem ..................99
Storing settings (memory
function) ........................................ 103
Switching seat heating on/off .........98
Switching seat ventilation on/off ....98
Sensors (cleaning instructions) ....... 287
Service see ASSYST PLUS service interval
display
Service interval display
Displaying service messages .........283
Hiding service messages ...............283
Notes ............................................. 283
Service messages ..........................282
Service menu (on-board computer) . 206
Service products Brake fluid ..................................... 350
Capacities ...................................... 346
Coolant (engine) ............................ 350
Engine oil ....................................... 349
Fuel ................................................ 347
Important safety notes ..................344
Refrigerant (air-conditioning
system) .......................................... 350
Washer fluid ................................... 351Index15

Information for customers in
California
Under California law you may be entitled to a
replacement of your vehicle or a refund of the
purchase price or lease price, if after a
reasonable number of repair attempts
Mercedes-Benz USA, LLC and/or its
authorized repair or service facilities fail to fix
one or more substantial defects or
malfunctions in the vehicle that are covered
by its express warranty. During the period of
18 months from original delivery of the
vehicle or the accumulation of 18 000 miles
(approximately 29 000 km) on the odometer
of the vehicle, whichever occurs first, a
reasonable number of repair attempts is
presumed for a retail buyer or lessee if one or
more of the following occurs:(1)the same substantial defect or
malfunction results in a condition that is
likely to cause death or serious bodily
injury if the vehicle is driven, that defect
or malfunction has been subject to repair
two or more times, and you have directly
notified Mercedes-Benz USA, LLC in
writing of the need for its repair.(2)the same substantial defect or
malfunction of a less serious nature than
category (1) has been subject to repair
four or more times and you have directly
notified Mercedes-Benz in writing of the
need for its repair.(3)the vehicle is out of service by reason of
repair of the same or different substantial
defects or malfunctions for a cumulative
total of more than 30 calendar days.
Please send your written notice to:
Mercedes-Benz USA, LLC
Customer Assistance Center
One Mercedes Drive
Montvale, NJ 07645-0350
Maintenance
The Service and Warranty Booklet describes
all the necessary maintenance work which
should be done at regular intervals.
Always have the Service and Warranty
Booklet with you when you bring the vehicle
to an authorized Mercedes-Benz Center. The
service advisor will record every service for
you in the Service and Warranty Booklet.
Roadside Assistance
The Mercedes-Benz Roadside Assistance
Program offers technical help in the event of
a breakdown. Calls to the toll-free Roadside
Assistance Hotline are answered by our
agents 24 hours a day, 365 days a year.
1-800-FOR-MERCedes(1-800-367-6372)
(USA)
1-800-387-0100 (Canada)
For additional information, refer to the
Mercedes-Benz Roadside Assistance
Program brochure (USA) or the "Roadside
Assistance" section in the Service and
Warranty booklet (Canada). You will find both
in your vehicle literature portfolio.
Change of address or change of
ownership
In the event of a change of address, please
send us the "Change of Address Notice"
found in the Service and Warranty
Information Booklet, or simply call the
Mercedes-Benz Customer Assistance Center
(in the USA) at the hotline number
1-800-FOR-MERCedes(1-800-367-6372) or
Customer Service Center (in Canada) at
1-800-387-0100. This will assist us in
contacting you in a timely manner should the
need arise.
If you sell your Mercedes, please leave the
entire literature in the vehicle so that it is
available to the next owner.
22Introduction

GWARNING
If the BAS malfunctions, the brake system still
functions, but without the additional brake
boost available that the BAS would normally
provide in an emergency braking maneuver.
Therefore, the braking distance may increase.
BAS PLUS (Brake Assist System Plus)
BAS PLUS is only available in vehicles
equipped with DISTRONIC PLUS.
i Observe the "Important safety notes"
section ( Y page 59).
At speeds above approximately
20 mph (30 km/h), BAS PLUS assists you
when braking in hazardous situations and
uses the radar sensor system to evaluate the
traffic conditions.
i This device has been approved by the FCC
as a "Vehicular Radar System". The radar
sensor is intended for use in an automotive
radar system only. Removal, tampering, or
altering of the device will void any
warranties, and is not permitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
With the help of the radar sensor system, BAS
PLUS can detect obstacles that are in the
path of your vehicle for an extended period of
time.
At speeds up to approximately
40 mph (70 km/h), BAS PLUS can also detect
stationary obstacles, for example stopped or
parked vehicles.
Should you approach an obstacle and BAS
PLUS has detected a risk of collision, BAS
PLUS calculates the braking force necessary
to avoid a rear-end collision. Should you apply
the brakes forcefully, BAS PLUS can
automatically increase the braking force to a
level suitable for the traffic conditions.
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal.
R there is no longer any danger of a rear-end
collision.
R no obstacle is detected in front of your
vehicle.
BAS PLUS is then deactivated.
For BAS PLUS to assist you when driving, the
radar sensor system must be switched on and
operational, see "Radar sensor system" in the
index.
GWARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations. BAS
PLUS cannot intervene in these cases.
There is a risk of an accident. Always pay
careful attention to the traffic situation and be
ready to brake.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R the possibility of strong radar reflections,
for example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
GWARNING
BAS PLUS does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R in curves
As a result, BAS PLUS cannot intervene in
critical situations. There is a risk of an
60Driving safety systemsSafety

The system automatically adapts the low-
beam headlamp range depending on the
distance to the other vehicle. Once the
system no longer detects any other vehicles,
it reactivates the high-beam headlamps.
The system's optical sensor is located behind
the windshield near the overhead control
panel.XTo activate: activate the Adaptive
Highbeam Assist function using the on-
board computer ( Y page 207).XTurn the light switch to c or à .XPress the combination switch beyond the
pressure point in the direction of arrow :
( Y page 109).
If it is dark and the light sensor activates
the low-beam headlamps, the _
indicator lamp in the instrument cluster
lights up.
If you drive faster than approximately
28 mph (45 km/h):
the headlamp range is set automatically
depending on the distance between the
vehicle and other road users.
If you drive faster than approximately
35 mph (55 km/h) and no other road users
are identified:
the high-beam headlamps are switched on
automatically. The K indicator lamp in
the instrument cluster also lights up.When you drive slower than approximately
30 mph (45 km/h) or if other road users
are identified or if the roads are sufficiently
illuminated:
the high-beam headlamps are switched off
automatically. The K indicator lamp in
the instrument cluster goes out. The _
indicator lamp in the instrument cluster
stays on.XTo deactivate: move the combination
switch back to its normal position.
The _ indicator lamp in the instrument
cluster goes out.GWARNING
The Adaptive Highbeam Assist is only an aid
intended to support you while driving. The
driver is and remains responsible for proper
vehicle lighting in accordance with the
prevailing light, sight and traffic conditions.
The system may be impaired or unavailable
when
R visibility is poor, e.g. due to snow, rain, fog,
or heavy spray
R the optical sensor area of the windshield is
dirty, fogged up, or covered by a sticker for
example
The system cannot recognize the following
road users:
R Road users without a lighting system of
their own, e.g. pedestrians
R Road users with dim lighting of their own,
e.g. cyclists
R Road users whose lighting is obstructed,
e.g. road users behind a guardrail
R In some seldom cases, even road users with
a lighting system of their own may be
recognized too late or not at all.
The automatic high-beam headlamps will then
not be deactivated or it will be activated in
spite of preceding or oncoming road users.
This could endanger you and/or others and
cause an accident. Always pay close attention
to the traffic situation and switch off the high
beam manually if necessary.
Exterior lighting111Lights and windshield wipersZ

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops ( Y page 24).
Overview of climate control systems
Important safety notes
GWARNING
Severe conditions (e.g. strong air pollution)
may require replacement of the filter before
its scheduled replacement interval. A clogged
filter will reduce the air volume to the interior
and the windows could fog up, impairing
visibility and endangering you and others.
Have a blocked filter replaced at a Mercedes-
Benz Center as soon as possible.
GWARNING
Follow the recommended settings for heating
and cooling given on the following pages.
Otherwise, the windows could fog up,
impairing visibility and endangering you and
others.
The automatic climate control adjusts the
temperature and the humidity of the vehicle
interior and filters undesired substances from
the air.
The automatic climate control is only
operational when the engine is running. 11
Optimum operation is only achieved if you
drive with the side windows and sliding
sunroof/panorama roof with power tilt/
sliding panel closed.
i Ventilate the vehicle for a brief period
during warm weather, e.g. using the
convenience opening feature ( Y page 84).
This will speed up the cooling process and
the desired vehicle interior temperature
will be reached more quickly.
i The integrated filter can filter out most
particles of dust and completely filters out
pollen. A clogged filter reduces the amount
of air supplied to the vehicle interior. For
this reason, you should always observe the
interval for replacing the filter, which is
specified in the Service Booklet. As it
depends on environmental conditions, e.g.
heavy air pollution, the interval may be
shorter than stated in the Service Booklet.
i It is possible that the residual heat
function may be activated automatically an
hour after the SmartKey is removed. The
vehicle is then ventilated for 30 minutes to
dry the air-conditioning system.11 Automatic climate control: the residual heat function can only be activated/deactivated when the ignition
is switched off.122Overview of climate control systemsClimate control

Notes on using 3-zone automatic
climate control
The following contains instructions and
recommendations to enable you to get the
most out of your automatic climate control.
R Activate climate control using the à and
¿ buttons. The indicator lamps in the
à and ¿ buttons light up.
R In automatic mode, you can also use the
ñ button to set a climate mode
(FOCUS/MEDIUM/DIFFUSE). The
MEDIUM level is recommended.
R Set the temperature to 72 ‡ (22 †).
R Only use the "defrosting" function briefly
until the windshield is clear again.
R Only use "air-recirculation" mode briefly,
e.g. if there are unpleasant outside odors
or when in a tunnel. The windows could
otherwise fog up as, in air-recirculation
mode, no fresh air is drawn into the vehicle.
R Use the ZONE function to adopt the
temperature settings on the driver's side
for the front-passenger side and the rear
compartment as well. The indicator lamp in
the á button goes out.
R Use the residual heat function if you want
to heat or ventilate the vehicle interior
when the ignition is switched off. The
"residual heat" function can only be
activated or deactivated with the ignition
switched off.
Operating the climate control system
Activating/deactivating climate
control
Important information
GWARNING
When the climate control system is
deactivated, the outside air supply and
circulation are also deactivated. Only choose
this setting for a short time. Otherwise the
windows could fog up, impairing visibility and
endangering you and others.
i Switch on climate control primarily using
the à button ( Y page 127).
Activating/deactivatingXTurn the SmartKey to position 2 in the
ignition lock.XTo switch on: press the à button.
The indicator lamp in the à button lights
up. Airflow and air distribution are set to
automatic mode.
or
XPress the ^ button.
The indicator lamp in the ^ button goes
out. The previously selected settings come
into effect again.XTo switch off: press the ^ button.
The indicator lamp in the ^ button lights
up.
Activating/deactivating the cooling
with air dehumidification function
Important information
The cooling with air dehumidification function
is only available when the engine is running.
The air inside the vehicle is cooled and
dehumidified according to the temperature
selected.
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.
Condensation may drip from the underside of
the vehicle when it is in cooling mode. This is
normal and not a sign that there is a
malfunction.
126Operating the climate control systemClimate control

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