2014 MERCEDES-BENZ C-CLASS SALOON stop start

Key
Display messages
Possible causes/consequences and
M
MSolutions Â
Key does not Key does not
belong to vehicle belong to vehicle You have put the wrong key in the ignition lock.
X Use the correct key. Â
Replace key Replace key The key needs to be replaced.
X Visit a qualified specialist workshop. Â
Change key batter‐ Change key batter‐
ies ies The key batteries are discharged.
X Replace the batteries (Y page 94).Â
Key not detected Key not detected
(white display mes-
sage) The key is currently undetected.
X Change the location of the key in the vehicle.
If the key still cannot be detected: X Insert the key into the ignition lock and turn it to the desired
position. Â
Key not detected Key not detected
(red display message) The 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.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Locate the key.
X Press aon the steering wheel to confirm the display mes-
sage. 350
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Because there is interference from a strong source of radio waves,
the key is not detected whilst the engine is running.
A warning tone also sounds.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Operate the vehicle with the key in the ignition lock if necessary. Â
Remove starting Remove starting
button, then button, then
insert key insert key The key is continually undetected.
The key detection function has a temporary malfunction or is
faulty. A warning tone also sounds.
X Insert the key into the ignition lock and turn it to the desired
position.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
Safety
Seat belts Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ü
N
Only for certain countries: the red seat belt warning lamp lights up for
6 seconds after the engine starts.
The seat belt warning lamp reminds the driver and front passenger to fasten
their seat belts.
X Fasten your seat belt (Y page 49).ü
N
Only for certain countries: the red seat belt warning lamp lights up after the
engine starts. In addition, a warning tone sounds for up to 6 seconds.
The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 49).
The warning tone ceases. Wa
rning and indi cator lamps in the instrument cluster
351On-board computer and displays Z

Safety systems
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions J
N
The yellow brake system warning lamp lights up while the engine is running
or the ECO start/stop function is activated.
Hybrid vehicle: the yellow brake system warning lamp is shown in driving
condition READY.
G WARNING
The brake system is malfunctioning and the braking characteristics may be
affected.
There is a risk of an accident. X If the multifunction display shows a display message, please observe this.
X Drive on carefully.
X Visit a qualified specialist workshop. J
N
The red brake system warning lamp is lit while the engine is running.
Hybrid vehicles: the red brake system warning lamp is shown in driving con-
dition READY.
A warning tone also sounds.
G WARNING
The brake boosting effect is malfunctioning and the braking characteristics
may be affected.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying attention to
road and traffic conditions. Do not continue driving under any circumstan-
ces.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. Warning and indicator lamps in the instrument cluster
353On-board computer and displays Z

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ÷
N
The yellow ESP ®
warning lamp is lit while the engine is running.
Hybrid vehicles: the yellow ESP ®
warning lamp is shown in driving condition
READY.
ESP ®
, BAS, BAS PLUS, COLLISION PREVENTION ASSIST PLUS, PRE ‑SAFE®
,
PRE‑SAFE ®
PLUS, PRE‑SAFE ®
Brake, HOLD function, hill start assist,
ESP ®
trailer stabilisation, Crosswind Assist, adaptive brake lights, STEER
CONTROL, Active Lane Keeping Assist and Active Blind Spot Assist are
unavailable due to a malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions
listed above.
The braking distance may thus increase in an emergency braking situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Visit a qualified specialist workshop. å
N
The yellow ESP ®
OFF warning lamp is lit while the engine is running or the
ECO start/stop function is activated.
Hybrid vehicles: the yellow ESP ®
warning lamp is shown in driving condition
READY.
ESP ®
is deactivated.
G WARNING
If ESP ®
is deactivated, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Reactivate ESP ®
.
In rare cases (Y page 81), it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 80).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Drive on carefully.
X Have ESP ®
checked at a qualified specialist workshop. 358
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Engine
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ;
N
The yellow engine diagnostics warning lamp lights up while the engine is
running.
There may be a fault, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engine may be running in emergency mode.
X Have the vehicle checked as soon as possible at a qualified specialist work-
shop.
Vehicles with a diesel engine: the fuel tank has been run dry (Y page 203).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emergency running
mode is cancelled. The vehicle need not be checked. 8
N
The yellow reserve fuel warning lamp is on while the engine is running.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level drops into the reserve range.
X Refuel at the nearest filling station. ?
N
The red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the bar display.
The temperature sensor for the coolant temperature gauge is faulty.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traffic condi-
tions, and switch off the engine. Do not continue driving under any circum- stances.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Consult a qualified specialist workshop. 360
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ?
N
The red coolant warning lamp comes on while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked
or the electric engine radiator fan may be malfunctioning.
The coolant is too hot and the engine is no longer being cooled sufficiently.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic condi-
tions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Leave the vehicle and keep a safe distance from the vehicle until the engine
has cooled down.
X Check the coolant level and top up the coolant, observing the warning notes
(Y page 393).
X If you have to top up the coolant frequently, have the engine cooling system
checked.
X Make sure that the air supply to the engine radiator is not blocked, e.g. by
frozen slush.
X Do not start the engine again until the coolant temperature is below 120 †.
The engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g. driving in
mountainous terrain and stop-start traffic. ?
N
The red coolant warning lamp comes on while the engine is running. A
warning tone also sounds.
The coolant temperature has exceeded 120 †. The airflow to the engine radi- ator may be blocked or the coolant level may be too low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine is overhea-
ted can cause some fluids which may have leaked into the engine compart-
ment to catch fire.
In addition, steam from an overheated engine can cause serious burns, which
can occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic condi-
tions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away (Y page 207).Warning and indicator lamps in the instrument cluster
361On-board computer and displays Z

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions X
Leave the vehicle and keep a safe distance from the vehicle until the engine
has cooled down.
X Check the coolant level and top up the coolant, observing the warning notes
(Y page 393).
X If you have to top up the coolant frequently, have the engine cooling system
checked.
X Make sure that the air supply to the engine radiator is not blocked, e.g. by
frozen slush.
X If the coolant temperature is below 120 †, you can continue driving to the
nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g. driving in
mountainous terrain and stop-start traffic. Hybrid system
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions J
N
The yellow RBS (Recuperative Brake System) warning lamp is on. In addi-
tion, a warning tone may sound.
G Risk of accident
RBS is malfunctioning. The automatic engine switch-off function may also be deactivated.
X Observe the messages in the multifunction display (Y page 314).
X Drive on carefully.
X Visit a qualified specialist workshop. 362
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Closing the bonnet
X
Lower the bonnet and let it fall from a
height of approximately 20 cm.
X Check that the bonnet has engaged prop-
erly.
If the bonnet can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force. Radiator
Do not cover up the radiator. Do not use ther-
mal mats, insect protection covers or any-
thing similar. Doing so can cause the Onboard Diagnostics System to display inaccurate val-
ues. Some of these values are legally required
and must always be correct. Engine oil
General notes Depending on your driving style, the vehicle
consumes up to 0.8 litres of oil per 1,000 km.
The oil consumption may be higher than this
when the vehicle is new or if you frequently
drive at high engine speeds.
Depending on the engine, the oil dipstick may be installed at a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly, wait approximately
30 minutes before carrying out the meas-
urement. Checking the oil level using the oil dip-
stick G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. Example
X Pull oil dipstick :out of the oil dipstick
tube.
X Wipe off oil dipstick :.
X Slowly 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.
X If the oil level has dropped to MIN mark =
or below, top up with 1.0 l of engine oil.
Adding engine oil G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. 392
Engine compartmentMaintenance and care