check engine MERCEDES-BENZ C-Class SEDAN 2015 W205 Owner's Guide

Display messages
Possible causes/consequences and
0050
0050Solutions DISTRONIC
DISTRONIC
PLUS
PLUSCur‐
Cur‐
rently
rently Unavailable
Unavailable
See
See Operator's
Operator's Man‐
Man‐
ual
ual DISTRONIC PLUS is temporarily inoperative.
DISTRONIC PLUS Steering Assist and Stop&Go Pilot are also tem-
porarily inoperative.
Possible causes are:
R function is impaired due to heavy rain or snow.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
A warning tone also sounds.
When the causes stated above no longer apply, the display mes-
sage disappears.
DISTRONIC PLUS is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 174).
X Restart the engine. DISTRONIC PLUS DISTRONIC PLUS
Inoperative Inoperative DISTRONIC PLUS is defective.
The following may have also failed:
R BAS PLUS with Cross-Traffic Assist
R PRE-SAFE ®
Brake
R DISTRONIC PLUS with Steering Assist and Stop&Go Pilot
A warning tone also sounds.
X Visit a qualified specialist workshop. DISTRONIC DISTRONIC
PLUS
PLUSSus‐
Sus‐
pended
pended You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
X Remove your foot from the accelerator pedal. DISTRONIC PLUS
DISTRONIC PLUS
- - - mph - - - mph An activation condition for DISTRONIC PLUS is not fulfilled.
X Check the activation conditions for DISTRONIC PLUS
(Y page 185). Display
messages
275On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions 00CC
Steering Malfunc‐ Steering Malfunc‐
tion See Opera‐ tion See Opera‐
tor's Manual tor's Manual The electric steering lock is malfunctioning.
G WARNING
The steering may be locked by the electric steering lock.
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.
X Secure the vehicle against rolling away (Y page 174).
X Do not drive on and consult the nearest qualified specialist
workshop. _
Before Starting Before Starting
the Engine, Turn the Engine, Turn
Steering Wheel Steering Wheel The electric steering lock was unable to unlock the steering.
X Remove the key from the ignition lock.
X To unlock the steering, move the steering wheel slightly.
X Insert the key into the ignition lock again. Phone No Service
Phone No Service Your vehicle is outside the network provider's transmitter/
receiver range.
X Wait until the mobile phone operational readiness symbol
appears in the multifunction display. 00B2
Check Washer Fluid Check Washer Fluid The washer fluid level in the washer fluid reservoir has dropped
below the minimum.
X Add washer fluid (Y page 327).SmartKey
Display messages
Possible causes/consequences and
0050 0050Solutions 00AF
Key Does Not Key Does Not
Belong to Vehicle Belong to Vehicle You have put the wrong SmartKey in the ignition lock.
X Use the correct SmartKey. 00AF
Take Take
Your
YourKey
Keyfrom
from
Ignition
Ignition The SmartKey is in the ignition lock.
X Remove the SmartKey. 00AF
Obtain a New Key Obtain a New Key The SmartKey needs to be replaced.
X Visit a qualified specialist workshop. 282
Display
messagesOn-board computer and displays

Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 00E5
0051
The yellow ESP ®
warning lamp is lit while the engine is running.
ESP ®
, BAS, BAS PLUS, COLLISION PREVENTION ASSIST PLUS, PRE ‑SAFE®
,
PRE‑SAFE ®
PLUS, PRE‑SAFE ®
Brake, HOLD function, hill start assist, Cross-
wind Assist, 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 in an emergency braking situation can thus increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Visit a qualified specialist workshop. 00BB
0051
The yellow ESP ®
OFF warning lamp is lit while the engine is running or the
ECO start/stop function is activated.
ESP ®
is deactivated.
G WARNING
If ESP ®
is switched off, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Reactivate ESP ®
.
In rare cases (Y page 72), it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 72).
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. Warning and indicator lamps in the instrument cluster
289On-board computer and displays Z

Warning/
indicator
lamp
0051
0051 Signal type
Possible causes/consequences and 0050 0050Solutions 00490024
0051
0049 (USA only), 0024(Canada only): the red indicator lamp for the electric
parking brake flashes or is lit and/or the yellow warning lamp for the electric parking brake is lit.
X Observe the additional display messages in the multifunction display. 0075
0051
The red restraint system warning lamp is lit while the engine is running.
The restraint system is faulty.
G WARNING
The air bags or Emergency Tensioning Devices may either be triggered unin-
tentionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury. X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Have the restraint system checked at a qualified specialist workshop imme-
diately.
For further information about the restraint system, see (Y page 42).290
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Engine
Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 00B9
0051
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 (for vehicles with gasoline engines)
R in the fuel system
The emission limit values may be exceeded and the engine may be in emer-
gency mode.
X Have the vehicle checked as soon as possible at a qualified specialist work-
shop.
In some states, you must immediately visit a qualified specialist workshop as
soon as the yellow Check Engine warning lamp lights up. This is due to the legal
requirements in effect in these states. If in doubt, check whether such legal
regulations apply in the state in which you are currently driving. 00B6
0051
The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
X Refuel at the nearest gas station. 00B6
0051
The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the 00B9Check 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.
X Check that the fuel filler cap is correctly closed.
X If the fuel filler cap is not correctly closed: close the fuel filler cap.
X If the fuel filler cap is closed: visit a qualified specialist workshop.00AC
0051
The red coolant warning lamp lights up while the engine is running and the
coolant temperature gage is at the start of the bar display.
The temperature sensor for the coolant temperature gage is defective.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
X Pull 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.
X Secure the vehicle against rolling away (Y page 174).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
291On-board computer and displays Z

Warning/
indicator
lamp
0051
0051 Signal type
Possible causes/consequences and 0050 0050Solutions 00AC
0051
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 Pull over and stop the vehicle safely and switch off the engine, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 174).
X Leave the vehicle and keep a safe distance from the vehicle until the engine
has cooled down.
X Check the coolant level and add coolant, observing the warning notes
(Y page 327).
X If you need to add coolant more often than usual, have the engine coolant
system checked.
X Make sure that the air supply to the engine radiator is not blocked, e.g. by
snow, slush or ice.
X Do not start the engine again until the coolant temperature is below 248 ‡
(120 †). Otherwise, the engine could be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in mountainous
terrain, and stop-and-go traffic. 00AC
0051
The red coolant warning lamp comes on while the engine is running. A
warning tone also sounds.
The coolant temperature has exceeded 248 ‡ (120 †). The airflow to the
engine radiator may be blocked or the coolant level may be too low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some fluids which may have leaked into the engine compartment to catch fire.
Steam from the overheated engine can also cause serious burns which can
occur just by opening the hood.
There is a risk of injury.
X Observe the additional display messages in the multifunction display.
X Pull over and stop the vehicle safely and switch off the engine, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 174).292
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions X
Leave the vehicle and keep a safe distance from the vehicle until the engine
has cooled down.
X Check the coolant level and add coolant, observing the warning notes
(Y page 327).
X If you need to add coolant more often than usual, have the engine coolant
system checked.
X Make sure that the air supply to the engine radiator is not blocked, e.g. by
snow, slush or ice.
X At coolant temperatures below 248 ‡(120 †), drive to the nearest qualified
specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in mountainous
terrain, and stop-and-go traffic. Driving systems
Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 00BA
0051
The red distance warning lamp lights up while the vehicle is in motion. A
warning tone also sounds.
You are approaching a vehicle or a stationary obstacle in your line of travel at too high a speed.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to brake or take
evasive action.
Further information on PRE ‑SAFE®
Brake (Y page 74).
For further information about the distance warning function of COLLISION
PREVENTION ASSIST PLUS, see (Y page 69). Warning and indicator lamps in the instrument cluster
293On-board computer and displays Z

Vehicle
Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 00CC
0051
The red power steering warning lamp is lit while the engine is running.
The power steering is malfunctioning.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident. X Check whether you are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified specialist
workshop.
X If you are unable to steer safely: do not drive on. Contact the nearest
qualified specialist workshop. Warning and indicator lamps in the instrument cluster
295On-board computer and displays Z

!
Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood. Example
X Make sure that the windshield wipers are
turned off.
X Pull release lever 0043on the hood.
The hood is released. X
Reach into the gap, pull hood catch han-
dle 0044up and lift the hood.
If you lift the hood by approximately 15 in
(40 cm), the hood is opened and held open automatically by the gas-filled strut.
Closing the hood X
Lower the hood and let it fall from a height
of approximately 8 in (20 cm).
X Check 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. Radiator
Do not cover up the radiator, such as with a
thermal mat or insect protection cover. The
readings of the on-board-diagnostic system
may otherwise be inaccurate. Some of these
readings are required by law and must be
accurate at all times. Engine oil
General notes Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per
600 miles (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 in 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 about 30 minutes
before carrying out the measurement.
Checking the oil level using the oil dip-
stick G
WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following. Engine compartment
325Maintenance and care Z

X
Replace cap 0043on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.
X Check the oil level again with the oil dip-
stick (Y page 325).
Further information on engine oil
(Y page 400). Additional service products
Checking coolant level G
WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following. G
WARNING
The engine cooling system is pressurized, par- ticularly when the engine is warm. When
opening the cap, you could be scalded by hotcoolant spraying out. There is a risk of injury.
Let the engine cool down before opening the
cap. Wear eye and hand protection when
opening the cap. Open the cap slowly half a
turn to allow pressure to escape. X
Park the vehicle on a level surface. Only check the coolant level when the vehi-
cle is on a level surface and the engine has
cooled down.
X Turn the SmartKey to position 2in the igni-
tion lock (Y page 157).
or
X On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 157).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).
X Turn the SmartKey to position
0(Y page 157) in the ignition lock.
or
X On vehicles with KEYLESS-GO, pull the
Start/Stop button from the ignition lock
(Y page 157).
X Slowly turn cap 0043half a turn counter-
clockwise to allow excess pressure to
escape.
X Turn cap 0043further counter-clockwise and
remove it.
If the coolant is at the level of marker bar 0087
in the filler neck when cold, there is enough coolant in coolant expansion tank 0044.
If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar 0087in the filler
neck when warm, there is enough coolant
in expansion tank 0044.
X If necessary, add coolant that has been tes-
ted and approved by Mercedes-Benz.
X Replace cap 0043and turn it clockwise as far
as it will go.
For further information on coolant, see
(Y page 401).
Adding washer fluid to the windshield
washer system G
WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot. Engine compartment
327Maintenance and care
Z