warning lights MERCEDES-BENZ C-CLASS COUPE 2011 Workshop Manual

Display messages Possible causes/consequences and
M Solutions
J
Brake immediately A malfunction has occurred while the HOLD function or DIS-
TRONIC PLUS is active.
or
Vehicles with manual transmission: with the HOLD function acti-
vated, you have either:
R
opened the driver's doo rand released the sea tbelt or
R switched off the engine or
R opened the bonnet
At one may also sound at regular intervals. The tone becomes
louder if you attempt to lock the vehicle.
You cannot start the engine.
X Paying attention to the traffic situation, immediately depress the
brake pedal firmly and hold until the display message disap-
pears.
X Prevent the vehicle from rolling away before you leave it
(Y page 321).
You can restart the engine. J
Check brake fluid
level G
Risk of accident
There is insufficien tbrake fluid in the brake fluid reservoir. In addi-
tion, the red Jwarning lamp in the instrument cluster lights
up and a warning tone sounds.
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 circumstances.
X Apply the parking brake.
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the error. #
Check brake wear The brake pads/linings have reached their wearl
imit.
X Visit a qualified specialist workshop. PRE-SAFE
inoperative See
Owner's Man. G
Risk of injury
Important function sof PRE-SAFE ®
have failed .All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. Display messages
241On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
ý G
Risk of injury
If the symbol appears in the multifunction display, aseat belt
tongue has not been clipped into a rear seat belt buckle.
X If necessary, ask the occupants in the rear to fasten their seat
belts.
For further information on the status indicator for the rear seat
belts: (Y page 54). Child seat in
wrong position
See Owner's Manual G
Risk of injury
Vehicles with automatic child seat recognition on the front-
passenger seat: the child seat is positioned incorrectly.
X Fit the child seat in the correct position. G
Risk of injury
Vehicles with automatic child seat recognition on the front-
passenger seat: the automatic child seat recognition sensor is
faulty.
X Visit a qualified specialist workshop. 6
Restraint
sys. mal‐
function Consult
workshop G
Risk of injury
There is a malfunction in the SRS (Supplemental Restraint Sys-
tem). The 6warning lamp also lights up in the instrument clus-
ter.
X Visit a qualified specialist workshop. 6
Front
left malfunc‐
tion Consult work‐
shop or
Front right malfunction
Consult workshop G
Risk of injury
SRS has malfunctioned at the front on the left or right. The 6
warning lamp also lights up in the instrument cluster.
X Visit a qualified specialist workshop. Display messages
243On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
6
Rear left malfunc‐
tion Consult work‐
shop or
Rear right malfunction Con‐
sult workshop G
Risk of injury
SRS has malfunctioned at the rear on the left or right. The 6
warning lamp also lights up in the instrumen tcluster.
X Visit a qualified specialist workshop. 6
Left
windowbag mal‐
function Consult
workshop or
Right windowbag malfunc‐
tion Consult work‐
shop G
Risk of injury
There is a malfunction in the left-hand and/or right-hand window-
bag. The 6warning lamp also lights up in the instrumen tclus-
ter.
X Visit a qualified specialist workshop. Lights (4-button multifunction steering wheel)
i Display messages about LEDs:
This display message will only appear if all LEDs have failed. Displa
ymessages Possible causes/consequences and
M Solutions
b
Left corner. light
or
Right corner. light The left or right-hand cornering light is faulty.
X
Chec kwhether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. b
Left dipped beam
or
Right dipped-beam The left or right-hand dipped-beamh
eadlamp is faulty.
X Check whether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. b
Trailer left tail
lamp or
Trailer right tail lamp The left or right-hand trailer tail lamp is faulty.
X
Check whether you are permitted to change the bulb yourself.
or
X Visit a qualified specialist workshop. 244
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
b
Left daytime driv‐
ing lamp
or
Right daytime driving lamp The lef
torright daytime driving lamp is defective.
X Check whether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. b
Malfunction The exterior lighting is faulty.
X
Visit a qualified specialist workshop. Vehicles with trailer tow hitch: a fuse may have blown.
X
Check the fuses (Y page 333).
X If necessary, replace the blown fuse. Observe the warning notes
as you do so.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. b
AUTO
lights inoper‐
ative The light sensor is faulty.
X
Visit a qualified specialist workshop. b
Switch off lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X
Turn the light switch to Ã.Lights (12-button multifunction steering wheel)
i Display messages about LEDs:
This display message will only appear if all LEDs have failed. Display messages
247On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
b
Front
left parking
lamp or
Front right parking lamp The front left or front right parking lamp is faulty.
X
Chec kwhether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. b
Reversing light The reversing lamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. b
Rear left side
marker lamp or
Rear right side marker lamp The rear left or right side marker lamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. b
Left daytime driv‐
ing lamp or
Right daytime driving
lamp The left or right-hand daytime driving lamp is defective.
X
Check whether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. b
Intell. Light Sys‐
tem inoperative The Intelligent Light System is faulty. The lights remain available
without the Intelligent Light System.
X
Visit a qualified specialist workshop. b
Malfunction See
Owner's Manual The exterior lighting is faulty.
X
Visit a qualified specialist workshop. Vehicles with trailer tow hitch: a fuse may have blown.
X
Check the fuses (Y page 333).
X If necessary, replace the blown fuse. Observe the warning notes
as you do so.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. b
AUTO
lights inoper‐
ative The light sensor is faulty.
X
Visit a qualified specialist workshop. 250
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
b
Switch off lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Tur nthe light switch to Ã. Adaptive Main-beam
Assist inoperative Adaptive Highbeam Assist is faulty.
X
Visit a qualified specialist workshop. Adaptive Main-beam
Assist currently
unavailable See
Owner's Manual Adaptive Highbeam Assist is deactivated and temporarily inoper-
ative if:
R
the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
X Cleant he windscreen.
Adaptive Highbeam Assist is available again if:
R the dirt (e.g. slush) drops away while the vehicle is in motion.
R the system detects that the camera is fully operational again.
The Adaptive Main-beam Assist available again message
is displayed. Engine (4-button multifunction steering wheel)
Display messages Possible causes/consequences and
M Solutions
Top up
coolant The coolant level is too low.
X Top up the coolant, observing the warning notes when doing so
(Y page 303).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. ?
Stop vehicle Sw.
eng. Off The coolant is too hot.
Aw
arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Wait until the display message disappears before restarting the
engine. Otherwise, there is a risk of engine damage.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately. Display messages
251On-board computer and displays Z

Warning and indicator lamps in the instrument cluster
Seat belt
Problem Possible causes/consequences and
M Solutions
7
Only for certain coun-
tries: the red sea
tbelt
warning lamp lights up
for six seconds after
the engine starts. The seat belt warning lamp reminds the driver and fron
tpassenger
to fasten their seat belts.
X Faste nyour seat belt (Y page 51). 7
Only for certain coun-
tries: the red seat belt
warning lamp lights up
after the engine starts.
In addition, a warning
tone sounds for up to
six seconds.
G
Risk of injury
The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 51).
The warning tone ceases. 7
The red seat belt warn-
ing lamp lights up after
the engine starts, as
soon as the driver's or
the front-passenger
door is closed. G
Risk of injury
The driver or front passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 51).
The warning lamp goes out. G
Risk of injury
There are objects on the front-passenger seat.
X Remove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out. Warning and indicator lamps in the instrument cluster
273On-board computer and displays Z

Safety systems
Problem Possible causes/consequences and
M Solutions
J
The red brake system
warning lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
G
Risk of accident
There is insufficient brake fluid in the fluid reservoir.
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 circumstances.
X Apply the parking brake.
X Consult a qualified specialist workshop immediately.
X Observe the additional display messages in the multifunction
display.
Do not top up the brake fluid. This does not correct the error. !
The yellow ABS warning
lamp is lit while the
engine is running.
G
Risk of accident
ABS (Anti-lock Brake System) has been deactivated due to a fault.
For this reason, BAS (Brake Assist), BAS PLUS, ESP ®
(Electronic
Stability Program), PRE-SAFE ®
,P RE-SAFE ®
Brake ,the HOLD func-
tion, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation are also deactivated, for example.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit 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 trans-
mission, will not be available. Warning and indicator lamps in the instrument cluster
275On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
!
The yellow ABS warning
lamp is lit while the
engine is running. G
Risk of accident
ABS is temporarily unavailable. Therefore, BAS, BAS PLUS, ESP ®
,
EBD (electronic brake force distribution), PRE-SAFE ®
,
PRE-SAFE ®
Brake, the HOLD function, hill start assist, the adaptive
brake lights and ESP ®
trailer stabilisation, for example, are also
deactivated.
Self diagnosis is not yet complete.
or
For example, the on-board voltage may be insufficient.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
ATTENTION ASSIST is deactivated.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements, at a speed above 20 km/h.
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. !
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds. G
Risk of accident
EBD is faulty. Therefore, ABS,B AS, BAS PLUS, ESP®
, PRE-SAFE ®
,
PRE-SAFE ®
Brake, the HOLD function, hill start assist, the adaptive
brake lights and ESP ®
trailer stabilisation, for example, are not
available either.
The brake system continue sto function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
ATTENTION ASSIST is deactivated.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 276
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
J֌!
The red brake warning
lamp, the yellow ESP
®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running. G
Risk of accident
ABS and ESP ®
are malfunctioning. Therefore, BAS, BAS PLUS,
EBD, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD function, hill start
assist, the adaptive brake lights and ESP ®
trailer stabilisation, for
example, are not available either due to a malfunction.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
ATTENTION ASSIST is deactivated.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. ÷
The yellow ESP
®
warn-
ing lamp flashes while
the vehicle is in motion. G
Risk of accident
ESP ®
or traction control has intervened because there is a risk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
X Only depress the accelerator pedal as far as necessary when
pulling away.
X Release the accelerator pedal while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Vehicles with a 12-button multifunction steering wheel only: do
not deactivate ESP ®
.
For exceptions: (Y page 67). å
Vehicles with a 12-but-
ton multifunction steer-
ing wheel only:
The yellow ESP
®
OFF
warning lamp is lit while
the engine is running. G
Risk of accident
ESP ®
and ESP ®
trailer stabilisation are deactivated. ESP ®
will not
stabilise the vehicle if it starts to skid or if awheel starts to spin.
X Reactivate ESP ®
.
Exceptions: (Y page 67).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Have ESP ®
checked at a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
277On-board computer and displays Z