2012 MERCEDES-BENZ C-Class SEDAN maintenance

Driving tips
General driving tips
Important safety notes
GWARNING
Always remember that you must concentrate
primarily on driving the vehicle. The driver's
concentration must always be directed
primarily at road traffic. For your own safety
and that of others, we recommend that you
stop the vehicle at a safe place and in
accordance with the traffic conditions before
making or accepting a phone call.
Comply with all legal requirements if you use
the telephone while driving. Use the hands-
free system and only use the telephone when
road, weather and traffic conditions permit. In
some jurisdictions, it is forbidden for drivers
to use mobile phones while driving.
Only operate the audio system or COMAND
(Cockpit Management and Data System) in
compliance with all legal requirements and
when the road, weather and traffic conditions
permit. You may otherwise not be able to
observe the traffic conditions, endangering
yourself and others.
Remember that your vehicle covers a distance
of 44 feet (approximately 14 m) a second
when it is traveling at only 30 mph
(approximately 50 km/h).
Drive sensibly – save fuel
Observe the following tips to save fuel:
XThe tires should always be inflated to the
recommended tire pressure.XRemove unnecessary loads.XRemove roof racks when they are not
needed.XWarm up the engine at low engine speeds.XAvoid frequent acceleration or braking.XHave all maintenance work carried out as
indicated by the service intervals in the
Service Booklet or by the service interval
display.Fuel consumption also increases when
driving in cold weather, in stop-and-go traffic
and in mountainous terrain.
Drinking and drivingGWARNING
Drinking and driving and/or taking drugs and
driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and
judgment.
The possibility of a serious or even fatal
accident are greatly increased when you drink
or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs.
Pedals
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 that 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.
Rolling with the engine switched off
GWARNING
There is no power assistance for the steering
and the brake when the engine is not running.
Steering and braking requires significantly
more effort and you could lose control of the
vehicle and cause an accident as a result.
Do not turn off the engine while the vehicle is
in motion.
Driving tips155Driving and parkingZ

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

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).
Important safety notes
You will find an illustration of the instrument
cluster in the "At a glance" section
( Y page 29).
GWARNING
A driver's attention to the road and traffic
conditions must always be his/her primary
focus when driving.
For your safety and the safety of others,
selecting features through the multifunction
steering wheel should only be done by the
driver when traffic and road conditions permit
it to be done safely.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h ), your vehicle is
covering a distance of 44 feet (approximately
14 m) every second.
GWARNING
No messages will be displayed if either the
instrument cluster or the multifunction
display is inoperative.
As a result, you will not be able to see
information about your driving conditions,
such as
R speed
R outside temperature
R warning/indicator lamps
Rmalfunction/warning messages
R failure of any systems
Driving characteristics may be impaired.
If you must continue to drive, do so with added
caution. Contact an authorized Mercedes-
Benz Center as soon as possible.GWARNING
Malfunction and warning messages are only
indicated for certain systems and are
intentionally not very detailed. The
malfunction and warning messages are
simply a reminder with respect to the
operation of certain systems. They do not
replace the owner's and/or driver's
responsibility to maintain the vehicle's
operating safety. Have all required
maintenance and safety checks performed on
the vehicle. Bring the vehicle to an authorized
Mercedes-Benz Center to address the
malfunction and warning messages.
Displays and operation
Coolant temperature display
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.
The coolant temperature gauge is in the
instrument cluster on the left-hand side.
Under normal operating conditions and with
the specified coolant level, the coolant
temperature may rise to 248 ‡ (120 †).
194Displays and operationOn-board computer and displays

TiresProblemPossible causes/consequences and M Solutionsh
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.
Canada only:
The yellow tire pressure
monitor warning lamp
(pressure loss) is lit.GRisk of accident
The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XObserve the additional display messages in the multifunction
display.XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 319).XIf necessary, change a wheel ( Y page 334).h
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
60 seconds and then
remains lit.The tire pressure monitor is faulty.XObserve the additional display messages in the multifunction
display.XVisit a qualified specialist workshop.GWARNING
Each tire, including the spare (if provided), should be checked at least every two weeks 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, if available, 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
1 minute and then remain continuously illuminated. This sequence will be repeated every time
250Warning and indicator lamps in the instrument clusterOn-board computer and displays

Useful information ............................278
Engine compartment ........................278
Maintenance ...................................... 282
Care .................................................... 283277Maintenance and care

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).
Engine compartment
Hood
Opening the hood
GWARNING
Do not pull the release lever while the vehicle
is in motion. Otherwise, the hood could be
forced open by passing air flow.
This could cause the hood to come loose and
injure you and/or others.
GWARNING
Do not open the hood when the engine is
overheated. You could be seriously injured.
Observe the coolant temperature gauge to
determine whether the engine may be
overheated. If you see flames or smoke
coming from the engine compartment, move
away from the vehicle. Wait until the engine
has cooled. If necessary, call the fire
department.
GWARNING
There is a risk of injury if the hood is open,
even if the engine is not running.
Some engine components can become very
hot.
To avoid the risk of burns, only touch those
components described in the Operator's
Manual and observe the relevant safety notes.
GWARNING
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for
approximately 30 seconds or may even
restart after the engine has been turned off.
Stay clear of fan blades.
GWARNING
The engine is equipped with a transistorized
ignition system. Because of the high voltage,
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnostic
socket) of the ignition system:
R with the engine running
R while starting the engine
R when the ignition is switched on and the
engine is turned manually
XMake sure that the windshield wipers are
switched off.GWARNING
The windshield wipers and wiper linkage
could be set in motion.
When the hood is open, you or others could
be injured by the wiper linkage.
Make sure that the windshield wipers are
switched off. Remove the SmartKey or make
sure that no ignition position has been
selected with KEYLESS-GO. All indicator
lamps must be off in the instrument cluster.
278Engine compartmentMaintenance and care

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

yourself. Do not spill any engine oil on hot
engine parts.HEnvironmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful
to the environment.
! Use only engine oils and oil filters that
have been approved for vehicles equipped
with a service system. A list of the engine
oils and oil filters tested and approved in
accordance with the Mercedes-Benz
Specifications for Service Products can be
called up by visiting http://
www.mbusa.com (USA only). More
information about tested and approved
engine oils and oil filters is available from
any authorized Mercedes-Benz Center.
Damage to the engine or exhaust system is
caused by the following:
R using engine oils and oil filters which
have not been specifically approved for
the service system.
R replacing the engine oil or oil filter after
the replacement interval required by the
service system has elapsed
R using engine oil additives.
! Do not add too much oil. If the oil level is
above the "max" mark on the dipstick, too
much oil has been added. This can lead to
damage to the engine or the catalytic
converter. Have excess oil siphoned off.
Example: engine oil cap
XTurn cap : counterclockwise and remove
it.XAdd engine oil.
If the oil level is at or below the MIN mark
on the oil dipstick,
add 0.55 to 1.1 US qt (0.5 to 1.0 l) engine
oil.XReplace cap : on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.XCheck the oil level again with the oil
dipstick ( Y page 279).
Further information on engine oil
( Y page 349).
Checking and adding other service
products
Checking the coolant level
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down.
XTurn the SmartKey to position
2 (Y page 137) in the ignition lock.
On vehicles with KEYLESS-GO, press the
Start/Stop button twice ( Y page 137).XCheck the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).GWARNING
In order to avoid any potentially serious burns:
R use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system, or
if the coolant temperature display indicates
that the coolant is overheated.
R do not remove the pressure cap on the
coolant reservoir if the coolant temperature
is above 158 ‡ (70 †). Allow the engine to
cool down before removing the cap. The
280Engine compartmentMaintenance and care