2012 MERCEDES-BENZ C-Class SEDAN Engine light

For your safety, we strongly recommend that you contact an authorized Mercedes-Benz Center
immediately to have the system checked. Otherwise the SRS may not be activated when needed
in an accident, which could result in serious or fatal injury, or it might deploy unexpectedly and
unnecessarily which could also result in injury.
Engine
ProblemPossible causes/consequences and M Solutions;
The yellow Check
Engine warning lamp
lights up while the
engine is running.There may be a malfunction, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system
R in the fuel system
The emission limit values may be exceeded and the engine may
be running in emergency mode.XHave the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states, you are required by law to immediately visit a
qualified specialist workshop as soon as the yellow Check
Engine warning lamp lights up. If in doubt, check whether such
legal regulations apply in the state/province in which you are
currently driving.
8
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion. In addition, the
yellow Check Engine
warning lamp ;
may light up.The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.XObserve the additional display messages in the multifunction
display.XCheck that the fuel filler cap is correctly closed.XIf the fuel filler cap is not correctly closed: close the fuel filler
cap.XIf the fuel filler cap is closed: visit a qualified specialist
workshop.8
The yellow reserve fuel
warning lamp lights up
while the engine is
running.The fuel level has dropped into the reserve range.XRefuel at the nearest gas station.246Warning and indicator lamps in the instrument clusterOn-board computer and displays

ProblemPossible causes/consequences and M Solutions?
The red coolant
warning lamp lights up
while the engine is
running and the coolant
temperature gauge is
at the start of the scale.The temperature sensor for the coolant temperature gauge is
defective.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.XApply the parking brake.XConsult a qualified specialist workshop.Warning and indicator lamps in the instrument cluster247On-board computer and displaysZ

GWARNING
Driving when your engine is overheated can cause some fluids which may have leaked into the
engine compartment to catch fire. You could be seriously burned.
Steam from an overheated engine can cause serious burns which can occur just by opening the
engine hood. Stay away from the engine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until the engine has cooled down.
! If the coolant temperature exceeds 248 ‡(120 †) do not continue driving. The engine will
otherwise be damaged.
Driving systems
ProblemPossible causes/consequences and M Solutions·
The red distance
warning lamp lights up
while the vehicle is in
motion. A warning tone
also sounds.GRisk of accident
The warning is issued if you approach a stationary vehicle or a
vehicle driving ahead of you at too high a speed.
XBe prepared to brake immediately.XPay careful attention to the traffic situation. You may have to
brake or take evasive action.
More information about DISTRONIC PLUS ( Y page 161) and
PRE-SAFE ®
Brake ( Y page 65).
Warning and indicator lamps in the instrument cluster249On-board computer and displaysZ

even if the SmartKey is removed from the
ignition lock or removed from the vehicle,
such as seat adjustment, steering wheel
adjustment, or the memory function
If children open a door, they could injure other
persons or get out of the vehicle and injure
themselves or be injured by following traffic.
Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and the child could be burned on these
parts.GWARNING
Never touch the heating element or sides of
the lighter; they are extremely hot. Hold the
knob only.
Make sure any children traveling with you do
not injure themselves or start a fire with the
hot cigarette lighter.
XTurn the SmartKey to position 2 in the
ignition lock.XTo open: slide cover : forwards until it
engages.XPress in cigarette lighter ;.
Cigarette lighter ; will pop out
automatically when the heating element is
red-hot.XTo close: press cover : briefly at the
front.
The cover moves back.12 V sockets
Points to observe before use
The sockets can be used for accessories, e.g.
lamps or mobile phone chargers with a
maximum current draw of 180 W (15 A).
If you use the sockets for long periods when
the engine is switched off, the battery may
discharge.
XTurn the SmartKey to position 1 in the
ignition lock.
i An emergency cut-out ensures that the
on-board voltage does not drop too low. If
the on-board voltage is too low, the power
to the sockets is automatically cut. This
ensures that there is sufficient power to
start the engine.
Socket in the rear-compartment center
console
XPull cover ; out by its top edge.XLift up the cover of socket :.
115 V power socket
GWARNING
The 115V AC socket operates at high voltage.
Use the 115V AC socket in the vehicle with
the same caution and prudence that you
exercise when using power outlets at home.
Keep any fluids away from the 115V AC
socket. Do not clean the socket with fluids or
tapered objects. Keep the 115V AC socket
Features263Stowing and featuresZ

XPull release lever : for the hood.
The hood is released.
! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
XReach into the gap, pull hood catch
handle ; up and lift the hood.
Once you have lifted the hood about
15 inches (40 cm), it is automatically
opened the rest of the way and held open
by the gas-filled struts.
Closing the hood
GWARNING
When closing the hood, use extreme caution
not to catch hands or fingers. Be careful that
you do not close the hood on anyone.
Make sure the hood is securely engaged
before driving off. Do not continue driving if
the hood can no longer engage after an
accident, for example. The hood could
otherwise come loose while the vehicle is in
motion and injure you and/or others.
XLower the hood and let it fall from a height
of approximately 8 inches (20 cm).XCheck that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force.Engine oil
Notes on the oil level
Depending on the driving style, the vehicle
consumes up to 0.9 US qts. (0.8 l) of oil over
a distance of 600 miles (1000 km). The oil
consumption may be higher than this when
the vehicle is new or if you frequently drive at
high engine speeds.
Checking the oil level using the oil
dipstick
XPark the vehicle on a level surface.
To check the oil level with the engine at
normal operating temperature, switch the
engine off and wait for approximately five
minutes.XPull oil dipstick : out of the dipstick guide
tube.XWipe off oil dipstick :.XSlowly slide oil dipstick : into the guide
tube to the stop, and take it out again.
If the level is between MIN mark = and
MAX mark ;, the oil level is correct.XIf the oil level has sunk to MIN mark = or
below, add
0.55 to 1.1 US qt (0.5 to 1.0 liter) engine oil.
Adding engine oil
GWARNING
If engine oil comes into contact with hot
engine parts, it may ignite and you could burn
Engine compartment279Maintenance and careZ

the wheel that is diagonally opposite the
wheel you wish to change.
Securing the vehicle on slight downhill gradients
XOn downhill gradients: place chocks or
other suitable items in front of the wheels
of the front and rear axle.
Raising the vehicle
GWARNING
When jacking up the vehicle, only use the jack
which has been specifically approved by
Mercedes-Benz for your vehicle.
The jack is designed exclusively for jacking up
the vehicle at the jacking points built into both
sides of the vehicle. The jack saddle must be
placed centrally under the jacking point. The
jack must always be vertical when in use,
especially on inclines or declines.
The jack is intended only for lifting the vehicle
briefly for wheel changes. It is not suited for
performing maintenance work under the
vehicle. To help avoid personal injury, use the
jack only to lift the vehicle during a wheel
change.
Never get beneath the vehicle while it is
supported by the jack. Keep hands and feet
away from the area under the lifted vehicle.
Always lower the vehicle onto sufficient
capacity jackstands before working under the
vehicle.
Always firmly engage the parking brake and
block the wheels with wheel chocks or other
sizable objects before raising the vehicle with
the jack. Do not disengage the parking brake
while the vehicle is raised.
Make sure that the ground on which the
vehicle is standing and where you place the
jack is solid, level and not slippery. If
necessary, use a large underlay. On slippery
surfaces, such as tiled floors, you should use
a non-slip underlay, for example a rubber mat.
Do not use wooden blocks or similar objects
as a jack underlay. Otherwise, the jack may
not be able to achieve its load-bearing
capacity if it is not at its full height.
Never start the engine when the vehicle is
raised.
Also observe the notes on the jack.XUsing lug wrench :, loosen the bolts on
the wheel you wish to change by about one
full turn. Do not unscrew the bolts
completely.
The jacking points are located just behind the
wheel housings of the front wheels and just
in front of the wheel housings of the rear
wheels (arrows).
Flat tire295Breakdown assistanceZ

dashboard. You could damage the
dashboard or the cover.XTo open: pull out cover : slightly at the
bottom in the direction of arrow =.XPull cover : outwards in the direction of
arrow ; and remove it.XTo close: clip in cover : on the front of
the dashboard.XFold cover : inwards until it engages.
Fuse box in the engine compartment
XMake sure that the windshield wipers are
turned off.GWARNING
Make sure that the windshield wipers are
switched off and that the SmartKey is
removed from the ignition lock before you
open the cover of the fuse box. Otherwise, the
windshield wipers and the wiper rods above
the cover could be set in motion. This could
lead to you or others being injured by the
wiper rods.
XOpen the hood ( Y page 278).XRemove any existing moisture from the
fuse box using a dry cloth.XTake lines ; from the guides.XTo open: open clamps :.XRemove the fuse box cover forwards.
!
Make sure that no moisture can enter the
fuse box when the cover is open.
XTo close: check whether the rubber seal is
lying correctly in the cover.XInsert the cover at the rear of the fuse box
into the retainer.XFold down the cover and close clamps :.XSecure lines ; in the guides.
!
The cover must be seated properly,
otherwise moisture or dirt could impair the
function of the fuses.
XClose the hood ( Y page 279).
Fuse box in the trunk
XOpen the trunk lid ( Y page 80).306FusesBreakdown assistance

Fuel
Important safety notesGWARNING
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.
Premium-grade unleaded gasoline
! To ensure the longevity and full
performance of the engine, only premium-
grade unleaded gasoline may be used.
If there is no premium-grade unleaded
gasoline available and regular-grade
unleaded gasoline may be used; please
observe the following precautions:
R only fill the fuel tank to half full with
regular-grade unleaded gasoline and fill
the rest with premium-grade unleaded
gasoline as soon as possible.
R do not drive at the maximum speed.
R avoid sudden acceleration.
R if the vehicle is carrying a light load, e.g.
two passengers without luggage, do not
allow the engine to rev above
3,000 rpm.
R if the vehicle is fully loaded or is being
operated in mountainous terrain, do not
depress the accelerator pedal further
than Ô of the pedal travel.
Flexible fuel vehicles
Important safety notes
Flexible fuel vehicles can be recognized by
the sticker on the inside of the filler flap.
Flexible fuel vehicles can be operated with
premium-grade unleaded gasoline and
ethanol (E85) or a mixture of both. Ethanol
fuel (E85) is a mixture of approximately 85%
ethanol and 15% unleaded gasoline.
GWARNING
Ethanol fuel (E85) and its vapors are highly
flammable, poisonous and highly
combustible. Ethanol fuel causes serious
injury if it ignites, if it comes into contact with
your skin or if you inhale the vapors. Avoid
inhaling ethanol vapors and ethanol coming
into contact with your skin. Before refueling,
extinguish all naked flames. Never allow
sparks or smoking materials near ethanol.
Changing the fuel type
For best performance and drivability, it is
recommended that you use either one or the
other fuel. Avoid alternating regularly
between the two different types of fuel.
When changing between the fuel types,
ensure that the following conditions are met:
R the fuel level is below half full.
R the fuel level is above the reserve level. This
is identifiable by the fuel tank reserve
warning lamp not being lit.
R you add more than 5 gallons (20 liters) of
fuel.
R you switch off the engine before refueling.
R the engine is started and runs for at least
five minutes immediately after refueling.
These precautions should prevent the
possibility of engine difficulties arising from
changing to a different fuel type.
If the engine still doesn't run correctly, refuel
with at least 3 US gal (12 l) of premium-grade
unleaded gasoline. This may improve the
running of the engine.
Service products and capacities347Technical dataZ