air conditioning MERCEDES-BENZ C-Class SEDAN 2012 W204 Owner's Manual

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

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

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

cold tires on a fully loaded vehicle and for the
maximum permissible vehicle speed.
The tire pressure table contains the
recommended tire pressures for cold tires
under various operating conditions, i.e.
differing load and speed conditions.
Increased vehicle weight due to
optional equipment
This is the combined weight of all standard
and optional equipment available for the
vehicle, regardless of whether it is actually
installed on the vehicle or not.
Rim
This is the part of the wheel on which the tire
is mounted.
GAWR (Gross Axle Weight Rating)
The GAWR is the maximum permissible axle
weight. The actual load on an axle must never
exceed the gross axle weight rating. The
gross axle weight rating can be found on the
vehicle identification plate on the B-pillar on
the driver's side.
Speed rating
The speed rating is part of the tire
identification. It specifies the speed range for
which the tire is approved.
GVW (Gross Vehicle Weight)
The gross vehicle weight comprises the
weight of the vehicle including fuel, tools, the
spare wheel, accessories installed,
occupants, luggage and the drawbar
noseweight, if applicable. The gross vehicle
weight must not exceed the gross vehicle
weight rating GVWR as specified on the
vehicle identification plate on the B pillar on
the driver's side.
GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permissible gross
weight of a fully loaded vehicle (the weight of
the vehicle including all accessories,
occupants, fuel, luggage and the drawbar
noseweight, if applicable). The gross vehicle
weight rating is specified on the vehicle
identification plate on the B-pillar on the
driver's side.
Maximum loaded vehicle weight
The maximum weight is the sum of the curb
weight of the vehicle, the weight of the
accessories, the total load limit and the
weight of the optional equipment installed at
the factory.
Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa is the
equivalent of 1 psi. Another unit for tire
pressure is bar. There are 100 kilopascals
(kPa) to 1 bar.
Load index
In addition to the load bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifies the load bearing
capacity more precisely.
Curb weight
The weight of a vehicle with standard
equipment including the maximum capacity
of fuel, oil and coolant. It also includes the air-
conditioning system and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage.
332Definition of terms for tires and loadingWheels and tires

Refrigerant of the air-conditioning
system
The air-conditioning system is filled with
R134a refrigerant and a special PAG
lubricant.
! Never use refrigerant R 12 (CFC) or
mineral lubricants. Otherwise, you could
damage the air-conditioning system.
Brake fluid
GWARNING
Over a period of time, the brake fluid absorbs
moisture from the air; this lowers its boiling
point.
If the boiling point of the brake fluid is too low,
vapor pockets may form in the brake system
when the brakes are applied hard (e.g. when
driving downhill). This would impair braking
efficiency.
You should have the brake fluid renewed at
regular intervals. The brake fluid change
intervals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz. Information about approved brake
fluids can be obtained from any authorized
Mercedes-Benz Center or on the Internet at
http://bevo.mercedes-benz.com.
Coolant
Important safety notes
The coolant is a mixture of water and
antifreeze/corrosion inhibitor. It performs
the following tasks:
R corrosion protection
R antifreeze protection
R raising the boiling point
The engine cooling system is filled at the
factory with coolant that contains an
antifreeze/corrosion inhibitor that ensures
protection down to approximately -35 ‡
(-37 †).
! Only add coolant that has been premixed
with the desired antifreeze protection.
Otherwise, the engine could be damaged.
Further information on coolants and on
filling can be found in the Mercedes-Benz
Specifications for Service Products, MB
Approval 310.1, e.g. on the Internet at
http://bevo.mercedes-benz.com . You can
also consult an authorized Mercedes-Benz
Center.
! Always use a suitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
If the coolant has antifreeze protection down
to -35 ‡ (-37 †), the boiling point of the
coolant under operating conditions is
approximately 266 ‡ (130 †).
Your vehicle has a range of aluminum
components. Aluminum components in the
engine make it necessary to use antifreeze/
corrosion inhibitor coolant that has been
specifically formulated to protect the
aluminum parts. Using other antifreeze/
corrosion inhibitors without these
characteristics affects the service life.
The coolant must be used throughout the year
in order to maintain the necessary corrosion
350Service products and capacitiesTechnical data