info MERCEDES-BENZ C-Class SEDAN 2012 W204 Service Manual

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

Useful information ............................136
Breaking-in notes .............................. 136
Driving ............................................... 136
Automatic transmission ...................142
Refueling ............................................ 150
Parking ............................................... 153
Driving tips ........................................ 155
Driving systems ................................ 159135Driving and parking

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).
Breaking-in notes
The first 1000 miles (1500 km)
The more you look after the engine when it is
new, the more satisfied you will be with its
performance in the future.
R Drive at varying vehicle speeds and engine
speeds for the first 1000 miles (1500 km)
for this reason.
R Avoid overstraining the vehicle during this
period, e.g. driving at full throttle.
R Change gear in good time, at the latest
when the tachometer needle is 2
/ 3 of the
way to the red area in the tachometer
display.
R If possible, drive in drive program E (in AMG
vehicles in drive program C) for the first
1000 miles (1500 km).
R Do not manually shift to a lower gear to
brake the vehicle.
R If possible, do not depress the accelerator
pedal past the point of resistance
(kickdown).
R Only select shift ranges 3, 2 or 1 when
driving slowly, e.g. in mountainous terrain.
After 1000 miles (1500 km), you can increase
the engine speed gradually and bring the
vehicle up to full speed.
Additional breaking-in notes for AMG
vehicles:
R do not drive faster than 85 mph
(140 km/h) in the first 1000 miles
(1500 km).
R only allow the engine to reach a maximum
engine speed of 4500 rpm briefly.
R change gear in good time.
i You should also observe these notes on
running in if the engine or parts of the drive
train on your vehicle have been replaced.
i Always observe the respective speed
restrictions.
AMG vehicles with rear axle locking
differential
Your vehicle is equipped with a self-locking
differential on the rear axle. For better
protection of the differential on the rear axle,
carry out an oil change after a breaking-in
phase of 2000 miles (3000 km). This oil
change extends the service life of the
differential. Have the oil change carried out
at a qualified specialist workshop. Mercedes-
Benz recommends that you use an authorized
Mercedes-Benz Center for this purpose.
Driving
Important safety notes
GWARNING
Make sure absolutely no objects are
obstructing the pedals' range of movement.
Keep the driver's footwell clear of all
obstacles. If there are any floormats or
carpets in the footwell, make sure the pedals
still have sufficient clearance.
During sudden driving or braking maneuvers
the objects could get caught between the
pedals. You could then no longer brake or
accelerate. This could lead to accidents and
injury.
136DrivingDriving and parking

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

ANeutral
Do not shift the transmission to N
while driving. The transmission
could otherwise be damaged.
No power is transmitted from the
engine to the drive wheels.
Releasing the brakes will allow you
to move the vehicle freely, e.g. to
push it or tow it.
If ESP ®
is deactivated or faulty:
only shift the transmission to
position N if the vehicle is in danger
of skidding, e.g. on icy roads.
! Rolling in neutral N can damage
the drive train.7Drive
The automatic transmission
changes gear automatically. All
forward gears are available.
Changing gear
The automatic transmission shifts to the
individual gears automatically when it is in
transmission position D. This automatic
gearshifting behavior is determined by:
R a shift range restriction, if selected
R the selected drive program ( Y page 144)
R the position of the accelerator pedal
R the road speed
Driving tips
AMG vehicles
When shifting down, the double-clutch
function is active regardless of the currently
selected drive program. The double-clutch
function reduces load change reactions and
is conducive to a sporty driving style. The
sound generated by the double-clutch
function depends on the drive program
selected.
Kickdown
Use kickdown for maximum acceleration.
XVehicles for USA (except AMG
vehicles): fully depress the accelerator
pedal.
The transmission shifts to a lower gear
depending on the engine speed.XVehicles for Canada and AMG vehicles:
depress the accelerator pedal beyond the
pressure point.
The transmission shifts to a lower gear
depending on the engine speed.
Working on the vehicle
GWARNING
When working on the vehicle, engage the
parking brake and shift the automatic
transmission into park position P. Otherwise
the vehicle could roll away which could result
in an accident and/or serious personal injury.
Program selector button
General information
The program selector button allows you to
choose between different driving
characteristics.
Example: program selector button
144Automatic transmissionDriving and parking

E EconomyComfortable, economical
drivingS SportSporty driving styleM ManualManual gearshifting
i
For further information on the automatic
drive program, see ( Y page 146).
Only change from automatic drive program
E or S to manual drive program M when the
vehicle is stationary.
XPress program selector button :
repeatedly until the letter for the desired
gearshift program appears in the
multifunction display.
i When the engine is started, the automatic
transmission always switches to automatic
drive program E (drive program C in AMG
vehicles).
AMG vehicles
Drive program selector with manual drive program
C Controlled
EfficiencyComfortable, economical
drivingS SportSporty driving styleS+ SportPlusExtremely sporty driving
styleM ManualManual gearshiftingRS RACE
STARTOptimal vehicle
acceleration from a
standstilli For further information on the automatic
drive program, see ( Y page 146).
Only change from automatic drive program C,
S or S+ to manual drive program M when the
vehicle is stationary.XTurn drive program selector : until the
desired drive program appears in the
multifunction display in the speedometer.
The drive program indicator on drive
program selector : lights up in red.
i
The automatic transmission shifts to
automatic drive program C each time the
engine is started.
i RS cannot be selected during normal
driving. For further information on RACE
START, see ( Y page 174).
Steering wheel paddle shifters
:Left-hand steering wheel paddle shifter;Right-hand steering wheel paddle shifter
In the automatic drive program, you can
restrict or derestrict the shift range by using
the steering wheel paddle shifters
( Y page 146).
In the manual drive program, you can change
gear using the steering wheel paddle shifters
or the selector lever ( Y page 147).
i You can only change gear with the
steering wheel paddle shifters when the
transmission is in position D.
Automatic transmission145Driving and parkingZ

an authorized Mercedes-Benz Center for
this purpose.
! If the parking brake is being tested on a
brake dynamometer, the ignition must be
switched off (SmartKey or Start/Stop
button in position 0 or 1), as ESP ®
will
otherwise automatically intervene. The
brake system could otherwise be damaged.
Refueling
Important safety notes
GWARNING
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
personal injury.
Never allow sparks, flames or smoking
materials near gasoline.
Turn off the engine before refueling.
Whenever you are around gasoline, avoid
inhaling fumes and any skin or clothing
contact.
Direct skin contact with fuels and the
inhalation of fuel vapors are damaging to your
health.
GWARNING
Overfilling of the fuel tank may create
pressure in the system which could cause a
gas discharge. This could cause the gasoline
to spray back out when removing the fuel
pump nozzle, which could cause personal
injury.
GWARNING
C 300 and C 300 Sport with automatic
transmission:
Flexible fuel vehicle (with Ethanol up to
E85! sticker on the fuel filler flap):
Ethanol fuel (E85) and its vapors are highly
flammable, poisonous and fast burning.
Ethanol fuel can cause serious injury if ignited,
or if you come into contact with it or inhale its
vapors. Avoid inhaling ethanol vapors. Avoid
skin contact with ethanol. Extinguish any
naked flames before refueling. Never allow
sparks or smoking materials near ethanol.
! Do not use diesel to refuel vehicles with a
gasoline engine. Even small amounts of the
wrong fuel result in damage to the fuel
system and engine.
! Do not switch on the ignition if you
accidentally refuel with the wrong fuel.
Otherwise, the fuel will enter the fuel lines.
Notify a qualified specialist workshop and
have the fuel tank and fuel lines drained
completely.
Gasoline
Fuel grade
! You should only refuel with premium-
grade unleaded gasoline, as this avoids
damaging the catalytic converter.
Flexible fuel vehicles, identifiable from the
label inside the fuel filler flap, can be
refueled with E85. For further information
on flexible fuel, see "Fuel".
If engine running problems are apparent,
have the cause checked immediately and
repaired. Excess unburned fuel can
otherwise enter the catalytic converter,
leading to overheating and possibly
causing a fire.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
i Only refuel with premium-grade unleaded
gasoline with a specified minimum octane
number of 91 (average value of 96 RON/
86 MON).
You will usually find information about the
fuel grade on the pump. If you cannot find
the label on the pump, ask the staff for
assistance.
150RefuelingDriving and parking

C 300 and C 300 Sport with automatic
transmission: you can tell a flexible fuel
vehicle by the label inside the fuel filler flap.
You can find more information under "Fuel"
( Y page 347), or by contacting an
authorized Mercedes-Benz Service Center
or visiting http://www.mbusa.com (USA
only).
Refueling
Fuel filler flap
The fuel filler flap is unlocked or locked
automatically when you open or close the
vehicle with the SmartKey or using KEYLESS-
GO.
The position of the fuel filler cap is displayed
in the instrument cluster 8. The arrow
next to the filling pump indicates the side of
the vehicle.
:To open the fuel filler flap;To insert the fuel filler cap=Tire pressure table?Fuel type
Opening
XSwitch off the engine.XRemove the SmartKey from the ignition
lock.
KEYLESS-GO: open the driver’s door. This
switches the ignition to position 0, which
corresponds to having removed theSmartKey. The driver’s door can be closed
again.XPress the fuel filler flap in the direction of
arrow :.
The fuel filler flap opens slightly.XOpen the fuel filler flap.XTurn the fuel filler cap counter-clockwise
and remove it.XInsert the fuel filler cap into the holder
bracket on the inside of filler flap ;.XCompletely insert the pump nozzle into the
filler neck and refuel.XOnly fill the tank until the pump nozzle
switches off.
! Overfilling the fuel tank could damage the
fuel system.
Closing
XReplace the fuel filler cap and turn it
clockwise. The fuel filler cap audibly
engages.XClose the fuel filler flap.
i If you drive with the fuel filler cap open,
reserve fuel warning lamp 8 flashes. In
addition, the ; Check Engine warning
lamp may light up. A message appears in
the multifunction display ( Y page 228).
For further information on warning and
indicator lamps in the instrument cluster,
see ( Y page 246).
i Close the fuel filler flap before locking the
vehicle. A locking pin otherwise prevents
the fuel filler flap from closing after the
vehicle has been locked.
Fuel filler flap emergency release
GWARNING
Avoid contact with the vehicle walls as they
may contain sharp edges. Otherwise, you
could injure yourself while releasing the fuel
filler flap.
Refueling151Driving and parkingZ

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

Limited braking performance on salt-
treated roadsGWARNING
The layer of salt on the brake discs and the
brake pads/linings may cause a delay in the
braking effect, resulting in a significantly
longer braking distance, which could lead to
an accident.
To avoid this danger, you should:
R occasionally brake carefully, without
putting other road users at risk, when you
are driving on salted roads. This helps to
remove any salt that may have started to
build up on the brake discs and the brake
pads/linings.
R maintain a greater distance to the vehicle
ahead and drive with particular care.
R carefully apply the brakes at the end of a
trip and immediately after commencing a
new trip, so that salt residues are removed
from the brake discs.
Servicing the brakes
! If the red brake warning lamp lights up in
the instrument cluster and you hear a
warning tone while the engine is running,
the brake fluid level may be too low.
Observe additional warning messages in
the multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked
immediately. This work should be carried
out at an authorized Mercedes-Benz
Center.
All checks and maintenance work on the
brake system must be carried out at a
qualified specialist workshop. This work
should be carried out at an authorized
Mercedes-Benz Center.
Have the brake pads replaced and the brake
fluid renewed at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz
Center.
GWARNING
If brake pads or brake fluid other than those
recommended are used, the braking
properties of the vehicle can be degraded to
an extent that safe braking is substantially
impaired. This could result in an accident.
! Vehicles with 4MATIC: function or
performance tests may only be carried out
on a 2-axle dynamometer. If you are
planning to have the vehicle tested on such
a dynamometer, contact an authorized
Mercedes-Benz Center to obtain further
information first. Otherwise, you could
damage the drive train or the brake system.
! Vehicles with 4MATIC: as the ESP®
system operates automatically, the engine
and the ignition must be switched off
(SmartKey in position 0 or 1 in the ignition
lock or Start/Stop button in position 0 or
1 ) while the parking brake is being tested
on a brake dynamometer.
Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
! Vehicles with 4MATIC: as the ESP®
system operates automatically, the engine
and the ignition system must be switched
off (SmartKey in position 0 or 1 in the
ignition lock or Start/Stop button in
position 0 or 1) when:
R testing the parking brake on a brake
dynamometer.
R you intend to have the vehicle towed with
the front axle raised.
Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
If your brake system is subject only to
moderate loads, you should test the
functionality of your brakes at regular
intervals by pressing firmly on the brake pedal
at high speeds. This improves the grip of the
brake pads.
Driving tips157Driving and parkingZ