trailer MERCEDES-BENZ C-CLASS COUPE 2011 Service Manual

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
Left cornering
light or
Right cor‐ nering light The lef
torright-hand cornering light 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 dipped beam
or
Right dipped beam The left or right-hand dipped-beam headlamp 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. b
Trailer left indi‐
cator or
Trailer right indicator The left or right-hand trailer tur
nsignal lamp is faulty.
X Check whether you are permitted to change the bulb yourself.
or
X Visit a qualified specialist workshop. b
Trailer brake lamp The trailer brake lamp is faulty.
X
Check whether you are permitted to change the bulb yourself.
or
X Visit a qualified specialist workshop. b
Rear
left indicator
or
Rear right indi‐ cator The rear left-hand or rear right-hand tur
nsignal is faulty.
X Check whether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. b
Front left indica‐
tor or
Front right indicator The front left-hand or front right-hand turn signal is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. 248
Display messagesOn-board computer and displays

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
Blind Spot Assist
currently unavail‐
able See Owner's
Manual or
Active Blind Spot Assist
currently unavail‐
able See Owner's
Manual Blind Spot Assis
torActive Blind Spot Assist is temporarily inop-
erative if:
R you have established the electrical connection between the
traile rand your vehicle.
R the sensors are dirty.
R its functio nis impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
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.
The yellow 9indicator lamps also light up in the exterior mir-
rors.
X When towing a trailer, confirm the display message with a.
When driving without a trailer:
Blind Spot Assist or Active Blind Spot Assist is operational again
and the display message disappears if:
R the dirt (e.g. slush) drops away while the vehicle is in motion.
R the system detects that the sensors are fully available again.
R the radar sensor system is back within the operating tempera-
ture range.
If the display message continues to be displayed:
X Cleant he sensors (Y page 309).
X Restart the engine. Blind Spot Assist
inoperative or
Active Blind Spot Assist inoperative Blind Spot Assist or Active Blind Spot Assist is faulty.
The yellow
9indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Parking Guidance
inoperative Parking Guidance is malfunctioning (Y
page 183).
X Restart the engine.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. Display messages
259On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
With the Hold function activated, 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 Shift the transmission to position P.
You can restart the engine. N The boot lid is open.
X
Close the boot lid. M G
Risk of accident
Vehicles with an anti-theft alarm system: the bonnet is open. 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 Apply the parking brake.
X Close the bonnet. C At least one door is open.
Awarning tone also sounds.
X Close all doors. _
Front left seat
backr. not locked
or
Front right seat backr. not
locked The driver's or front-passenger seat backres
tis not engaged. A
warning tone also sounds.
X Push the backrest back until it engages. Check trailer
hitch lock G
Risk of accident
Vehicles with a retractable trailer coupling:
The trailer tow hitch is not correctly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Apply the parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 201).266
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
N The boo
tlid is open.
X Close the boot lid. M G
Risk of accident
The bonnet is open .Awarning tone also sounds.
X Pull ove rand stop the vehicle safely as soo nas possible, paying
attention to road and traffic conditions.
X Apply the parking brake.
X Close the bonnet.
If the active bonnet (pedestrian protection) has been triggered:
X Reset the bonnet (Y page 300).
X Close the bonnet. Active bonnet
malfunction See
Owner's Manual The active bonnet (pedestrian protection) is not active due to a
malfunction.
X
Visit a qualified specialist workshop. C At least one door is open.
Awarning tone also sounds.
X Close all doors. _
Front left seat
backrest not locked
or
Front right seat backrest not
locked The driver's or front-passenger seat backres
tis not engaged. A
warning tone also sounds.
X Push the backrest back until it engages. j
Check trailer
hitch lock G
Risk of accident
The trailer tow hitch is not correctly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Apply the parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 201).268
Display messagesOn-board computer and displays

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

Problem Possible causes/consequences and
M Solutions
M
AMG vehicles only:
The yellow SPORT han-
dling mode warning
lamp is lit while the
engine is running.
G
Risk of accident
SPORT handling mode is activated. ESP ®
only stabilises the vehi-
cle in extreme situations. ESP ®
intervention may not be able to
provide sufficient assistance in such situations and the vehicle
may start to skid.
X Reactivate ESP ®
.
For exceptions: (Y page 67).
If ESP ®
cannot be activated:
X Have ESP ®
checked at a qualified specialist workshop. ֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. G
Risk of accident
ESP ®
, BAS, BAS PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD
function, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation are not available due to a malfunction .ESP ®
will not
stabilise the vehicle if it starts to skid or if awheel starts to spin.
The brake system continues to function normally, but without the
functions listed above.
ATTENTION ASSIST is deactivated.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 278
Warning and indicator lamps in the instrument clusterOn-board computer and displays