2011 MERCEDES-BENZ C-Class Engine

Display messagesPossible causes/consequences and M Solutionsb
Check Rear Left
Sidemarker Lamp
or
Check Rear Right
Sidemarker LampThe rear left or right side marker lamp is faulty.XCheck whether you are permitted to change the bulb yourself
( Y page 111).
or
XVisit a qualified specialist workshop.b
Check Left Daytime
Running Light
or
Check Right
Daytime Running
LightThe left or right-hand daytime running light is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 111).
or
XVisit a qualified specialist workshop.b
Active Headlamps
InoperativeThe active light function is faulty.XVisit a qualified specialist workshop.b
Malfunction See
Operator's ManualThe exterior lighting is faulty.XVisit a qualified specialist workshop.b
Auto Lamp Function
InoperativeThe light sensor is faulty.XVisit a qualified specialist workshop.b
Switch Off LightsThe lights are still switched on when you leave the vehicle. A
warning tone also sounds.XTurn the light switch to c.
Engine
Display messagesPossible causes/consequences and M Solutions+
Check Coolant
Level See
Operator's ManualThe coolant level is too low.XAdd coolant, observing the warning notes when doing so
( Y page 240).XIf coolant needs adding more often than usual, have the engine
coolant system checked at a qualified specialist workshop.194Display messagesOn-board computer and displays
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GWarning
Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn
if it comes into contact with hot engine parts. You could be seriously burned.
! The coolant level is too low. Avoid making long journeys with too little coolant in the cooling
system. The engine will otherwise be damaged.
The display messages and the corresponding symbol that indicate that the coolant level is
too low must not be ignored.
Display messagesPossible causes/consequences and M Solutions?
Coolant Level Low
Stop Vehicle Turn
Engine OffThe coolant is too hot.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XMake sure that the air supply to the radiator is not blocked, e.g.
by snow, slush or ice.XWait until the display message disappears before restarting the
engine. There is otherwise a risk of engine damage.XPay attention to the coolant temperature display.XIf the temperature increases again, visit a qualified specialist
workshop immediately.The poly-V-belt may have torn.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is OK:
XWait until the display message disappears before restarting the
engine. There is otherwise a risk of engine damage.XPay attention to the coolant temperature display.XVisit a qualified specialist workshop.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.
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! If the coolant temperature exceeds 248 ‡(120 †) do not continue driving. The engine will
otherwise be damaged.Display messagesPossible causes/consequences and M Solutions?The engine fan is faulty.XAt coolant temperatures below 248 ‡ (120 †), continue driving
to the next qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-start driving.#The battery is not being charged.
Possible causes are:
R a faulty alternator
R a torn poly-V-belt
R a malfunction in the electronicsXPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is OK:
XVisit a qualified specialist workshop.4
Check Engine Oil
At Next
Refueling Check
Engine Oil at Next
RefuelingThe engine oil level has dropped to a critical level.
A warning tone also sounds.XCheck the oil level ( Y page 239).XIf necessary, add the engine oil ( Y page 240).XHave the engine checked for leaks if engine oil has to be added
more often than usual.
Information on approved engine oils can be obtained from any qualified specialist workshop
or on the Internet at http://www.mbusa.com (USA only).
! The oil level is too low. Avoid long journeys with too little engine oil. There is a risk of
engine damage.
The display messages and the corresponding symbol that indicate that the oil level is too
low must not be ignored.
196Display messagesOn-board computer and displays
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Display messagesPossible causes/consequences and M Solutionsh
Check Tire PressureGRisk of accident
The tire pressure in one or more tires has dropped significantly.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XIf necessary, change a wheel ( Y page 286).XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 277).h
Correct Tire
PressureThe tire pressure is insufficient in at least one of the tires or the
tire pressure difference between the wheels is too great.XCheck the tire pressures at the next opportunity. If necessary,
correct the tire pressure ( Y page 277).
Vehicle
Display messagesPossible causes/consequences and M SolutionsShift to 'P' or 'N'
to Start EngineYou have attempted to start the engine with the transmission in
position R or D. XShift the transmission to position P or N.P
Shift to 'P'You turned off the engine with the Start/Stop button and opened
the driver's door while the transmission was in position N.
or
You have attempted to turn off the engine with the Start/Stop
button while the transmission was in position R or D.XShift the transmission to position P.AWagon: the tailgate is open.XClose the tailgate.NThe trunk lid is open. XClose the trunk lid.MGRisk of accident
The hood is open.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XClose the hood.200Display messagesOn-board computer and displays
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Display messagesPossible causes/consequences and M Solutions+
Obtain a new keyThe SmartKey needs to be replaced.XVisit a qualified specialist workshop.+
Replace Key BatteryThe batteries of the KEYLESS-GO key are discharged.XChange the batteries ( Y page 74).+
Don't Forget Your
KeyThe display message is displayed for a maximum of 60 seconds
and is just a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.XTake the KEYLESS-GO key with you when leaving the vehicle.+
Key Not Detected
(red display message)The KEYLESS-GO key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XLocate the KEYLESS-GO key.The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
A warning tone also sounds.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XOperate the vehicle with the KEYLESS-GO key in the ignition
lock if necessary.+
Key Not Detected
(white display
message)The KEYLESS-GO key cannot be detected at present.XChange the location of the key with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
XChange the location of the key with the KEYLESS-GO functions
in the vehicle.XOperate the vehicle with the KEYLESS-GO key in the ignition
lock if necessary.202Display messagesOn-board computer and displays
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Display messagesPossible causes/consequences and M Solutions+
Key Detected in
VehicleThe KEYLESS-GO key has been detected inside the vehicle during
locking.XRemove the KEYLESS-GO key from the vehicle.+
Remove 'Start'
Button and Insert
KeyKEYLESS-GO is temporarily malfunctioning or is defective. A
warning tone also sounds.XInsert the SmartKey into the ignition lock and turn it to the
desired position.XVisit a qualified specialist workshop.+
Close Doors to
Lock VehicleAt least one door is open. A warning tone also sounds.XClose all doors and lock the vehicle again.
Warning and indicator lamps in the instrument cluster
Brakes
ProblemPossible causes/consequences and M Solutions$ (USA only)
J (Canada only)
The red brake system
warning lamp comes on
while the vehicle is
moving. A warning tone
also sounds.You are driving with the parking brake engaged.XRelease the parking brake.
The warning lamp goes out and the warning tone ceases.$ (USA only)
J (Canada only)
The red brake system
warning lamp comes on
while the engine is
running. A warning tone
also sounds.GRisk of accident
There is insufficient brake fluid in the fluid reservoir.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.XEngage the parking brake.XConsult a qualified specialist workshop immediately.XObserve the additional display messages in the multifunction
display.
Do not add brake fluid. This will not rectify the problem.
Warning and indicator lamps in the instrument cluster203On-board computer and displaysBA 204 USA, CA Edition A 2011; 1; 5, en-UShereepeVersion: 3.0.3.62010-05-20T09:17:30+02:00 - Seite 203Z

GWarning
Driving with the brake warning lamp illuminated can result in an accident. Have your brake system
checked immediately if the brake warning lamp stays on. Do not add brake fluid before checking
the brake system.
Overfilling the brake fluid reservoir can result in spilling brake fluid on hot engine parts and the
brake fluid catching fire. You can be seriously burned.
Seat belts
ProblemPossible causes/consequences and M Solutions7
After starting the
engine, the red seat
belt warning lamp lights
up for 6 seconds.The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.XFasten your seat belt ( Y page 50).7
After starting the
engine, the red seat
belt warning lamp lights
up. In addition, a
warning tone sounds
for up to 6 seconds.GRisk of injury
The driver's seat belt is not fastened.
XFasten your seat belt ( Y page 50).
The warning tone ceases.7
The red seat belt
warning lamp lights up
after the engine starts,
as soon as the driver's
or the front-passenger
door is closed.GRisk of injury
The driver or front passenger has not fastened their seat belt.
XFasten your seat belt ( Y page 50).
The warning lamp goes out.GRisk of injury
There are objects on the front-passenger seat.
XRemove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out.204Warning and indicator lamps in the instrument clusterOn-board computer and displays
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Safety systemsProblemPossible causes/consequences and M Solutions!
The yellow ABS warning
lamp is lit while the
engine is running. GRisk of accident
ABS (Anti-lock Brake System) is deactivated due to a malfunction.
Therefore, ESP ®
(Electronic Stability Program), BAS (Brake Assist),
EBD (Electronic Brake force Distribution) and hill start assist are
also deactivated.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic
transmission, will not be available.
!
The yellow ABS warning
lamp is lit while the
engine is running.GRisk of accident
ABS is temporarily unavailable. ESP ®
, BAS and EBD, for example,
are therefore not available either.
Self diagnosis is not yet complete.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XCarefully drive a suitable distance making slight steering
movements at a speed above 12 mph (20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.206Warning and indicator lamps in the instrument clusterOn-board computer and displays
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