brake MERCEDES-BENZ C-CLASS COUPE 2011 Manual Online

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
Left
mirror indica‐
tor or
Right mir‐ ror indicator The turn signal in the left-hand or right-hand exterior mirror is
faulty.
X
Chec kwhether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. b
Third brake lamp The third brake 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-hand tail
lamp/brake lamp or
Right-hand tail lamp/brake lamp The left or right-hand tail lamp/brake 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 main beam
or
Right main beam The left or right-hand high beam 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 fog lamp
or
Right fog lamp The left-hand or right-hand front foglamp 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 fog lamp The rear foglamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 114).
or
X Visit a qualified specialist workshop. Display messages
249On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
Speed Limit Assist
currently unavail‐
able See Owner's
Manual Speed Limit Assis
tis deactivated and temporarily inoperative if:
R the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
Speed Limit Assist is operational againa nd the display message
disappears if:
R the dirt (e.g. slush) drops away while the vehicle is in motion.
R the system detects tha tthe camera is fully operational again.
If the display message continues to be displayed:
X Cleant he windscreen. Speed Limit Assist:
Unavailable in
this country Speed Limit Assist is only available in certain countries.
X
Drive on.
Speed Limit Assist is available again when you drive in a country
in which its use is approved. Speed Limit Assist
inoperative Speed Limit Assist is faulty.
X
Visit a qualified specialist workshop. HOLD
Off The HOLD function is deactivated. The vehicle is skidding.
Aw
arning tone also sounds.
X Reactivate the HOLD function later (Y page 177). The HOLD function is deactivated. When the brak
epedal is firmly
depressed, an activation condition is not fulfilled.
Aw arning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 177). Radar sensor
deactivated autom.
See Owner's Manual Vehicles with a navigation system: the vehicle is close to a radio
telescope facility and is therefore prohibited from transmitting any
radar signals. The radar sensor system has switched off automat-
ically (Y
page 363).
DISTRONI CPLUS (Y page 164) is deactivated automatically if it is
activated. Awarning tone also sounds.
Blind Spo tAssist (Y page 190) or Active Blind Spot Assist
(Y page 194) is deactivated automatically if it is activated. The
yellow 9indicator lamps also light up in the exterior mirrors.
BAS PLUS (Brake Assist PLUS) (Y page 66) and PRE-SAFE®
Brake
(Y page 71) are then also not available.
X Drive on.
Once you have moved far enough away from the radio telescope,
the above functions are available again. Display messages
257On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
Vehicles with Becker
®
MAP PILOT: if the Becker ®
MAP PILOT is
no tc onnected, the radar sensor system is deactivated automati-
cally.
BAS PLUS, DISTRONIC PLUS, Blind Spot Assist or Active Blind
Spot Assist and PRE-SAFE ®
Brake are not available.
X Connect the Becker ®
MAP PILOT, see the separate operating
instructions. Radar sensor
deactivated See
Owner's Manual The radar sensor system is deactivated.
X
Check whether or not the radar sensor system may be activated
(Y page 363).
X Switch on the radar sensor system (Y page 226).Lane Keeping
Assist currently
unavailable See
Owner's Manual or
Active Lane Keep‐ ing Assist cur‐
rently unavailable
See Owner's Manual Lane Keeping Assist or Active Lane Keeping Assist is deactivated
and temporarily inoperative if:
R
the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
R there are no lane markings for a longer period.
R the lane markings are worn, dark or covered, for example by dirt
or snow.
Lane Keeping Assist or Active Lane Keeping 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 camera is fully operational again.
If the display message continues to be displayed:
X Clean the windscreen. Lane Keeping
Assist inoperative
or
Active Lane Keeping Assist
inoperative Lane Keeping Assist or Active Lane Keeping Assist is faulty.
X
Visit a qualified specialist workshop. 258
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
DISTRONIC PLUS
currently unavail‐
able See Owner's
Manual DISTRONIC PLU
Sis deactivated and is temporarily inoperative if:
R the DISTRONIC PLUS cover in the radiator grille is dirty.
R the sensors in the bumpers are dirty.
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 its function is impaired due to heavy rain or snow.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Aw arning tone also sounds.
DISTRONIC PLU Sis operational againa nd the display message
disappears if:
R the dirt (e.g. slush) drops away while the vehicle is in motion.
R the system detects tha tthe sensors are fully available again.
R the system is within the operating temperature range.
If the display message continues to be displayed:
X Clean the DISTRONIC PLUS cover in the radiator grille
(Y page 309).
X Cleant he bumpers (Y page 309).
X Restart the engine. DISTRONIC PLUS
inoperative DISTRONIC PLUS is faulty. BAS PLUS and PRE-SAFE
®
Brake may
also have failed.
Aw arning tone also sounds.
X Visi taqualified specialist workshop. DISTRONIC PLUS
suspended You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
X
Take your foot off the accelerator pedal. DISTRONIC PLUS
--- km/h An activation condition for DISTRONIC PLUS is not fulfilled.
X
Check the activation conditions for DISTRONIC PLUS
(Y page 164). DISTRONIC PLUS and
SPEEDTRONIC
inoperative DISTRONIC PLUS and SPEEDTRONIC are faulty. A warning tone
also sounds.
X
Visit a qualified specialist workshop. Cruise control and
SPEEDTRONIC
inoperative Cruise control and SPEEDTRONIC are malfunctioning.
Aw
arning tone also sounds.
X Visi taqualified specialist workshop. Display messages
261On-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

Key (4-button multifunction steering wheel)
Display messages Possible causes/consequences and
M Solutions
Key does not
belong to vehicle You have put the wrong key in the ignition lock.
X
Use the correct key. +
Replace key The key needs to be replaced.
X
Visit a qualified specialist workshop. +
Change battery The batteries of the KEYLESS-GO key are discharged.
X
Change the batteries ( Ypage 80). Key not detected
(Red display message) The KEYLESS-GO key is not in the vehicle.
Aw
arning tone also sounds.
If the engine is switched off, you can no longer loc kthe 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 Apply the parking brake.
X Locate 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.
Aw
arning 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 Operate the vehicle with the key in the ignition lock if necessary. Key not detected
(White display mes-
sage) The KEYLESS-GO key cannot be detected at present.
X
Change the location of the key with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
X Change the location of the key with the KEYLESS-GO functions
in the vehicle.
X Operate the vehicle with the key in the ignition lock if necessary. +
Key still in vehi‐
cle The KEYLESS-GO key has been detected inside the vehicle during
locking.
X
Remove the KEYLESS-GO key from the vehicle. 270
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
+
Insert key KEYLESS-GO is temporarily malfunctioning or is defective.
Awarn-
ing tone also sounds.
X Insert the key into the ignition lock and turn it to the desired
position.
X Visi taqualified specialist workshop. Close doors
to lock veh. At least one door is open.
Awarning tone also sounds.
X Close all doors and loc kthe vehicle again. Key (12-button multifunction steering wheel)
Display messages Possible causes/consequences and
M Solutions
Â
Key does not
belong to vehicle You have put the wrong key in the ignition lock.
X
Use the correct key. Â
Replace key The key needs to be replaced.
X Visit a qualified specialist workshop. Â
Change key batter‐
ies The batteries of the KEYLESS-GO key are discharged.
X
Change the batteries (Y page 80).Â
Key not detected
(Red display message) The KEYLESS-GO key is not in the vehicle.
Aw
arning tone also sounds.
If the engine is switched off, you can no longer loc kthe 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 Apply the parking brake.
X Locate 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.
Aw
arning 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 Operate the vehicle with the key in the ignition lock if necessary. Display messages
271On-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