four wheel drive 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

Position of exterior mirror, front-
passenger side ............................... 102
Rear view camera .......................... 181
see PARKTRONIC
Parking aid
Parking Guidance ........................... 178
see Exterior mirrors
see PARKTRONIC
Parking brake
Display message ............................ 216
Notes/function .............................. 154
Parking Guidance
Display message ............................ 230
Important safety notes ..................178
Parking lamps (changing bulbs) ...... 115
PARKTRONIC Deactivating/activating .................177
Driving system ............................... 175
Function/notes ............................. 175
Problem (malfunction) ...................178
Range of the sensors .....................176
Warning display ............................. 177
PASSENGER AIR BAG OFF indicator
lamp ...................................................... 42
Pedals ................................................. 155
Permanent four-wheel drive see 4MATIC (permanent four-
wheel drive)
Plastic trim (cleaning instructions) . 288
Power washers .................................. 284
Power windows see Side windows
PRE-SAFE ®
Brake (vehicles with
DISTRONIC PLUS) Display message ............................ 218
Function/notes ................................ 65
Switching on/off ........................... 205
Warning lamp ................................. 249
Preventive occupant safety
system
see PRE-SAFE ®
(Preventive
occupant safety system)
Product information ............................ 21
Program selector button .................. 144
Pulling away Automatic transmission .................139Q
Qualified specialist workshop ........... 24
R
RACE START (AMG vehicles) ............. 174
RACETIMER (on-board computer) .... 211
Radar sensor system Activating/deactivating .................208
Display message ............................ 229
Radio
Selecting a station .........................201
see separate operating instructions
Reading lamp ..................................... 112
Rear compartment Setting the airflow .........................129
Setting the air vents ......................133
Rear fog lamp
Display message ............................ 223
Switching on/off ........................... 108
Rear seat
Display message ............................ 237
Folding the backrest forwards/
back ............................................... 257
Rear view camera
Cleaning instructions .....................287
Function/notes ............................. 181
Rear-view mirror
Anti-glare (manual) ........................101
Dipping (automatic) .......................102
Rear window blind ............................ 261
Rear window defroster Problem (malfunction) ...................130
Rear window heating
Switching on/off ........................... 130
Rear window wiper
Replacing the wiper blade .............. 118
Switching on/off ........................... 117
Refueling
Fuel gauge ....................................... 29
Important safety notes ..................150
Refueling process ..........................151
see Fuel
Releasing the parking lock
manually (automatic
transmission) ..................................... 149
14Index

considerably higher degree of effort is
necessary to brake and steer the vehicle.
Vehicles with automatic transmissionXApply the parking brake firmly.XShift the transmission to position P.
Using the SmartKey
XTurn the SmartKey to position 0 in the
ignition lock and remove it.
The immobilizer is activated.
i The SmartKey can only be removed if the
transmission is in position P.
Using KEYLESS-GO
XPress the Start/Stop button (Y page 137).
The engine stops and all the indicator
lamps in the instrument cluster go out.
i When the driver's door is closed, this
corresponds to SmartKey position 1. When
the driver's door is open, it corresponds to
SmartKey position 0 or "SmartKey
removed".
If you attempt to switch off the engine while
the selector lever is in a position other than
P , a message appears in the multifunction
display and you hear a tone.
Parking brake
GWARNING
Engaging the parking brake while the vehicle
is in motion can cause the rear wheels to lock
up. You could lose control of the vehicle and
cause an accident. In addition, the vehicle's
brake lights do not light up when the parking
brake is engaged.
GWARNING
When leaving the vehicle, always remove the
SmartKey from the starter switch, take it with
you, and lock the vehicle. Do not leave
children unattended in the vehicle, or with
access to an unlocked vehicle. Children could
release the parking brake and/or shift the
automatic transmission out of park position
P , either of which could result in an accident
and/or serious personal injury.XTo apply: depress parking brake ; firmly.
When the engine is running, the $ (USA
only) or J (Canada only) indicator lamp
lights up in the instrument cluster.XTo release: depress the brake pedal and
keep it depressed.XPull release handle :.
When the ignition is switched on or the
engine is running, the $ (USA only) or
J (Canada only) indicator lamp goes out
in the instrument cluster.
Parking the vehicle for a long period
If you leave the vehicle parked for longer than
four weeks, the battery may be damaged by
exhaustive discharge.
XConnect a trickle charger.
i You can obtain information about trickle
chargers from a qualified specialist
workshop, e.g. an authorized Mercedes-
Benz Center.
If you leave the vehicle parked for longer than
six weeks, the vehicle may suffer damage as
a result of lack of use.
XVisit a qualified specialist workshop and
seek advice.154ParkingDriving and parking

The multifunction display shows the RACE
START active message.
RACE START is deactivated when a speed of
approximately 30 mph (Canada: 50 km/h) is
reached. Drive program S+ is activated.
SPORT handling mode remains activated.
RACE START is deactivated immediately if
you release the accelerator pedal during
RACE START or if any of the activation
conditions are no longer fulfilled. The
multifunction display shows the RACE START
not possible See Operator's Manual
message.
i If RACE START is used repeatedly within
a short period of time, it is only available
again after the vehicle has been driven a
certain distance.
4MATIC (permanent four-wheel drive)
4MATIC ensures that all four wheels are
permanently driven. Together with ESP ®
, it
improves the traction of your vehicle
whenever a drive wheel spins due to
insufficient grip.
GWARNING
If a drive wheel is spinning due to insufficient
traction:
R While driving off, apply as little throttle as
possible.
R While driving, ease up on the accelerator
pedal.
R Adapt your speed and driving style to the
prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The 4MATIC cannot prevent accidents
resulting from excessive speed.
! Never tow the vehicle with one axle
raised. This may damage the transfer case.
Damage of this sort is not covered by the
Mercedes-Benz Limited Warranty. All
wheels must remain either on the ground
or be fully raised. Observe the instructions
for towing the vehicle with all wheels in full
contact with the ground.
i In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if
you use winter tires ( M+S tires), with snow
chains if necessary.
PARKTRONIC
Important safety notes
i PARKTRONIC is only available in Canada.
GWARNING
The PARKTRONIC is a supplemental system.
It is not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always remains with the driver.
GWARNING
Make sure no persons or animals are in or
near the area in which you are parking/
maneuvering. Otherwise, they could be
injured.
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is activated automatically when
you:
R switch on the ignition
R shift the transmission to position D, R or N
R release the parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper.
Driving systems175Driving and parkingZ

Display messagesPossible causes/consequences and M SolutionsCheck Tire
Pressure SoonGRisk of accident
The tire pressure loss warning system has detected a significant
loss in pressure.
A warning tone also sounds.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XCheck the tires and, if necessary, change the wheel
( Y page 334).XCheck the tire pressures and, if necessary, set to the correct
tire pressure.XRestart the tire pressure loss warning system when the tire
pressure is correct ( Y page 317).Check Tire Pressure
Then Restart Run
Flat IndicatorThe tire pressure loss warning system generated a display
message and has not been restarted since.XSet the correct tire pressure in all four tires.XRestart the tire pressure loss warning system ( Y page 317).Run Flat Indicator
InoperativeThe tire pressure loss warning system is defective.XVisit a qualified specialist workshop.Tire pressures
will be displayed
after driving a
few minutesThe tire pressure monitor is measuring the tire pressure.XDrive on.
The tire pressures appear in the multifunction display after you
have been driving for a few minutes.Tire Press. Monitor
InoperativeThe tire pressure monitor is defective.XVisit a qualified specialist workshop.Tire Press. Monitor
Inoperative No
Wheel SensorsThe wheels mounted do not have a suitable tire pressure sensor.
The tire pressure monitor is deactivated.XMount wheels with suitable tire pressure sensors.
The tire pressure monitor is activated automatically after driving
for a few minutes.234Display messagesOn-board computer and displays

GWARNING
The tire pressure loss warning system does
not provide a warning for wrongly selected tire
inflation pressures. Always adjust tire
inflation pressure according to the Tire and
Loading Information placard on the driver's
door B-pillar or on the tire inflation pressure
label located on the inside of the fuel filler flap.
The tire pressure loss warning system does
not replace regular checks of the tire inflation
pressures since a gradual pressure loss in
more than one tire cannot be detected by the
tire pressure loss warning system.
The tire pressure loss warning system is not
able to issue a warning due to a sudden
dramatic loss of tire inflation pressure (e.g.
tire blowout caused by a foreign object). In
this case bring the vehicle to a halt by carefully
applying the brakes and avoiding abrupt
steering maneuvers.
The function of the tire pressure loss warning
system is limited or delayed if:
R snow chains are mounted to your vehicle's
tires.
R road conditions are wintry.
R you are driving on sand or gravel.
R you adopt a very sporty driving style
(cornering at high speeds or driving with
high rates of acceleration).
R you are driving with a heavy load (in the
vehicle or on the roof).
Restarting the tire pressure loss
warning system
Restart the tire pressure loss warning system
if you have:
R changed the tire pressure
R changed the wheels or tires
R mount new wheels or tires
XBefore restarting, consult the Tire and
Loading Information placard on the
B-pillar on the driver's side or the tire
pressure table on the inside of the fuel filler
flap to ensure the tire pressure in all fourtires is set correctly for the current
operating conditions.XObserve the notes in the section on tire
pressures ( Y page 313).GWARNING
The tire pressure loss warning system can
only give reliable warnings if you have set the
correct tire pressure.
If an incorrect tire pressure is set, these
incorrect values will be monitored.
A tire with insufficient pressure results in
vehicle instability when driving, thus
increasing the risk of an accident.
XMake sure that the SmartKey is in
position 2 ( Y page 137) in the ignition lock.XPress the = or ; button to select the
Service menu.XPress the 9 or : button to select
Tire Pressure .XPress the a button.
The Run Flat Indicator Active
Press 'OK' to Restart message
appears in the multifunction display.
If you wish to confirm the restart:
XPress the a button.
The Tire Pressure Now OK? message
appears in the multifunction display.XPress 9 or : to select Yes.XPress the a button.
The Run Flat Indicator Restarted
message appears in the multifunction
display.
After a teach-in period, the tire pressure
loss warning system will monitor the set
tire pressures of all four tires.
If you wish to cancel the restart:
XPress the % button.
or
XIf the Tire Pressure Now OK? message
appears, press 9 or : to select
Cancel .318Tire pressureWheels and tires

XPress the a button.
The tire pressure values stored at the last
restart will continue to be monitored.
Tire pressure monitor
Important safety notes
If a tire pressure monitor system is installed,
the vehicle's wheels have sensors that
monitor the tire pressures in all four tires. The
tire pressure monitor warns you if the
pressure drops in one or more of the tires. The
tire pressure monitor only functions if the
correct wheel electronics units are installed
on all wheels.
The tire pressure monitor has a yellow
warning lamp in the instrument cluster for
indicating pressure loss/malfunctions (USA)
or pressure loss (Canada). Whether the
warning lamp flashes or lights up indicates
whether a tire pressure is too low or the tire
pressure monitoring system is
malfunctioning:
R if the warning lamp is lit continuously, the
tire pressure on one or more tires is
significantly too low. The tire pressure
monitor is not malfunctioning.
R USA only: if the warning lamp flashes for
60 seconds and then remains lit constantly,
the tire pressure monitor is malfunctioning.
GWARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire
pressure label on the inside of the fuel filler
flap. If your vehicle has tires of a different size
than the size indicated on the Tire and Loading
Information placard or the tire pressure label,
you should determine the proper tire pressure
for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires are significantly underinflated.
Accordingly, when the low tire pressure
telltale illuminates, you should stop and check
your tires as soon as possible, and inflate
them to the proper pressure. Driving on a
significantly underinflated tire causes the tire
to overheat and can lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle's
handling and stopping ability.
Please note that the TPMS is not a substitute
for proper tire maintenance, and it is the
driver's responsibility to maintain correct tire
pressure, even if underinflation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale.
USA only:
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined with
the low tire pressure telltale. When the
system detects a malfunction, the telltale will
flash for approximately one minute and then
remain continuously illuminated. This
sequence will be repeated every time the
vehicle is started as long as the malfunction
exists.
When the malfunction indicator is illuminated,
the system may not be able to detect or signal
low tire pressure as intended. TPMS
malfunctions may occur for a variety of
reasons, including the installation of
incompatible replacement or alternate tires
or wheels on the vehicle that prevent the
TPMS from functioning properly. Always
check the TPMS malfunction telltale after
replacing one or more tires or wheels on your
vehicle to ensure that the replacement or
alternate tires and wheels allow the TPMS to
continue to function properly.
i USA only:Tire pressure319Wheels and tiresZ

Tire pressure monitor warning
messages
If the tire pressure monitor detects a
significant pressure loss on one or more tires,
a warning message is shown in the
multifunction display. A warning tone also
sounds and the tire pressure warning lamp
lights up in the instrument cluster.
Each tire that is affected by a significant loss
of pressure is highlighted with a color.
If the Correct Tire Pressure message
appears in the multifunction display:
XCheck the tire pressure on all four wheels
and correct it if necessary.
i If the wheel positions on the vehicle are
interchanged, the tire pressures may be
displayed for the wrong positions for a
short time. This is rectified after a few
minutes of driving, and the tire pressures
are displayed for the correct positions.
Restarting the tire pressure monitor
GWARNING
It is the driver's responsibility to set the tire
pressure to the recommended cold tire
pressure. Underinflated tires affect the ability
to steer or brake the vehicle. You might lose
control over the vehicle.
When you restart the tire pressure monitor,
all existing warning messages are deleted and
the warning lamps go out. The monitor uses
the currently set tire pressures as the
reference values for monitoring. In most
cases, the tire pressure monitoring system
recognizes the new reference values
automatically.
However, you can also define reference
values manually as described here:
XSet the tire pressure ( Y page 313) to the
value recommended for the corresponding
driving situation on the Tire and Loading
Information placard on the driver's side
B-pillar.Additional tire pressure values for driving
at high speeds or with heavy loads can be
found in the tire pressure table on the
inside of the fuel filler flap.XMake sure that the tire pressure is correct
on all four wheels.XMake sure that the SmartKey is in position
2 in the ignition lock.XPress the = or ; button on the
steering wheel to select the Service
menu.XPress the 9 or : button to select
Tire Pressure .XPress the a button.
The multifunction display shows the
current tire pressure of the individual tires
or the Tire pressures will be
displayed after driving a few
minutes message.XPress the : button.
The Use Current Pressures as New
Reference Values message appears in
the multifunction display.
If you wish to confirm the restart:
XPress the a button.
The Tire Press. Monitor Restarted
message appears in the multifunction
display.
After driving for a few minutes, the system
checks whether the current tire pressures
are within the specified range. The new tire
pressures are then accepted as reference
values and monitored.
If you wish to cancel the restart:
XPress the % button.
The tire pressure values stored at the last
restart will continue to be monitored.Tire pressure321Wheels and tiresZ

the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance.GWARNING
If ice has formed on the road, tire traction will
be substantially reduced. Under such weather
conditions, drive, steer and brake with
extreme caution.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road
surfaces.
You should pay special attention to road
conditions when temperatures are around
the freezing point.
Mercedes-Benz recommends a minimum tire
tread depth of 1
/ 6 in (4 mm) for all four winter
tires ( Y page 312) to maintain normal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow covered
surfaces in comparison to summer tires.
Stopping distance, however, is still
considerably greater than when the road is
not covered with ice or snow. Take
appropriate care when driving.
! Avoid wheelspin. This can lead to damage
to the drive train.
Temperature
GWARNING
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heat build-up and possible tire
failure.
The temperature grades are A (the highest),
B, and C. These represent the tire's
resistance to the generation of heat and its
ability to dissipate heat when tested under
controlled conditions on a specified indoor
laboratory test wheel. Sustained high
temperature can cause the material of the tire
to degenerate and reduce tire life, and
excessive temperature can lead to sudden
tire failure. The grade C corresponds to a level
of performance which all passenger car tires
must meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades B and A
represent higher levels of performance on the
laboratory test wheel than the minimum
required by law.
Tire labeling
Tire labeling overview
The following markings are on the tire in
addition to the tire name (sales designation)
and the manufacturer's name:
:Uniform tire Quality Grading Standard
( Y page 331);DOT, Tire Identification Number
( Y page 330)=Maximum tire load ( Y page 325)?Maximum tire pressure ( Y page 316)AManufacturerBTire material ( Y page 331)CTire size designation, load-bearing
capacity and speed rating ( Y page 328)Tire labeling327Wheels and tiresZ