2014 MERCEDES-BENZ C-CLASS SALOON brake

Display messages
Possible causes/consequences and
M
MSolutions !
Turn on the igni‐ Turn on the igni‐
tion to release tion to release
the parking brake the parking brake The red
!indicator lamp lights up.
You attempted to release the electric parking brake while the igni-
tion was switched off.
X Switch the ignition on. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
Braking efficiency may be impaired.
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 circumstances.
X Secure the vehicle against rolling away (Y page 207).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the fault. #
Check brake pad Check brake pad
wear wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
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
Once the causes listed above no longer apply, the display message goes out.
COLLISION PREVENTION ASSIST 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 207).
X Restart the engine. 322
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
inoperative inoperative COLLISION PREVENTION ASSIST PLUS is temporarily inoperative
due to a malfunction. Adaptive Brake Assist may also have failed.
X Visit a qualified specialist workshop. PRE-SAFE inopera‐
PRE-SAFE inopera‐
tive See Owner's tive See Owner's
Manual Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. PRE-SAFE
PRE-SAFE
Functions
Functions
currently limited
currently limited
See Owner's Manual See Owner's Manual PRE
‑SAFE ®
PLUS or PRE ‑SAFE®
Brake is temporarily inoperative.
Possible causes:
R the 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
Once the causes listed above no longer apply, the display message
goes out.
PRE ‑SAFE ®
PLUS and PRE ‑SAFE®
Brake are 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 207).
X Restart the engine. PRE-SAFE PRE-SAFE
Functions
Functions
limited See Own‐
limited See Own‐
er's Manual er's Manual PRE
‑SAFE ®
PLUS or PRE‑ SAFE®
Brake is unavailable due to a mal-
function. BAS PLUS might also be deactivated.
X Visit a qualified specialist workshop. Display
messages
323On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Radar sensors
Radar sensors
dirty See Owner's dirty See Owner's
Manual Manual At least one of the following driving systems or driving safety sys-
tems is temporarily restricted or inoperative:
R PRE-SAFE ®
PLUS
R PRE-SAFE ®
Brake
R COLLISION PREVENTION ASSIST PLUS
R Active Lane Keeping Assist
R Active Blind Spot Assist
R DISTRONIC PLUS
Possible causes:
R the sensors in the radiator trim and/or in the bumpers are dirty
R the function of the driving system and/or driving safety system
is impaired due to heavy rain or snow
A warning tone also sounds.
Once the causes listed above no longer apply, the display message
goes out. All driving systems/driving safety systems are operative 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 207).
X Switch off the engine.
X Clean the sensors (Y page 401) in the following locations:
R in the radiator trim
R in the front bumper
R in the rear bumper, particularly in the middle of the rear
bumper
X Restart the engine.
The display message disappears. ü ü If this symbol appears in the multifunction display, a seat belt
tongue has been inserted into a rear seat belt buckle.
Further information on the status indicator for the rear seat belts
(Y page 50). 324
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions b
Trailer left indi‐ Trailer left indi‐
cator catororTrailer
Trailer
right indicator
right indicator The left or right-hand trailer turn signal lamp is faulty.
X Observe the separate operating instructions provided by the
trailer manufacturer. b
Trailer brake lamp Trailer brake lamp The trailer brake lamp is faulty.
X Observe the separate operating instructions provided by the
trailer manufacturer. b
Rear left indica‐ Rear left indica‐
tor tor
orRear right
Rear right
indicator
indicator The rear left-hand or rear right-hand turn signal is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 142).
or
X Visit a qualified specialist workshop. b
Front left indica‐ Front left indica‐
tor tor
orFront right
Front right
indicator
indicator The front left-hand or front right-hand turn signal is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 142).
or
X Visit a qualified specialist workshop. b
Left Left
mirror
mirror indica‐
indica‐
tor
tor orRight mir‐
Right mir‐
ror indicator
ror indicator The turn signal in the left-hand or right-hand exterior mirror is
faulty.
X Visit a qualified specialist workshop. b
Left brake lamp Left brake lamp
or
Right brake lamp
Right brake lamp The left or right-hand brake lamp is faulty.
X Visit a qualified specialist workshop. b
Third brake lamp Third brake lamp The third brake lamp is faulty.
X Visit a qualified specialist workshop. b
Left-hand tail Left-hand tail
lamp/ brake lamp/ brake
lamp lampor
Right-hand
Right-hand
tail lamp/ brake
tail lamp/ brake
lamp lamp The left or right-hand tail lamp/brake lamp is faulty.
X Visit a qualified specialist workshop. 330
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Park
Park
Assist
Assist inoper‐
inoper‐
ative
ative PARKTRONIC is malfunctioning or faulty.
X Follow the instructions and helpful hints in the "Problems with
PARKTRONIC" section (Y page 239).
If the display message continues to be displayed: X Visit a qualified specialist workshop. Active Parking Assist is unavailable or faulty.
X Switch off the ignition and restart the engine.
If Active Parking Assist continues to be unavailable (the jsymbol
is not shown in the multifunction display):
X Visit a qualified specialist workshop. Traffic Sign Traffic Sign
Assist currently Assist currently
unavailable See unavailable See
Owner's Manual Owner's Manual Traffic Sign Assist is temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
X Clean the windscreen.
If the system detects that the camera is fully operational, the dis-
play message disappears.
Traffic Sign Assist is operational again. Traffic Sign Traffic Sign
Assist inoperative Assist inoperative Traffic Sign Assist is faulty.
X Visit a qualified specialist workshop. ë
Off Off The HOLD function is deactivated. The vehicle is skidding.
A warning tone also sounds.
X Reactivate the HOLD function later (Y page 232). The HOLD function is deactivated. When the brake pedal is firmly
depressed, an activation condition is not fulfilled.
A warning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 232). DISTRONIC PLUS off DISTRONIC PLUS off DISTRONIC PLUS has been deactivated (Y
page 222).
If it was not deactivated by the driver, a warning tone also sounds. DISTRONIC PLUS
DISTRONIC PLUS
available again available again DISTRONIC PLUS is operational again after having been tempo-
rarily unavailable. You can now reactivate DISTRONIC PLUS
(Y
page 222). 340
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions DISTRONIC
DISTRONIC
PLUS
PLUScur‐
cur‐
rently
rently unavailable
unavailable
See Owner's Manual
See Owner's Manual DISTRONIC PLUS is temporarily inoperative.
DISTRONIC PLUS Steering Assist and Stop&Go Pilot are also tem-
porarily inoperative.
Possible causes:
R the 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.
Once the causes listed above no longer apply, the display message goes out.
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 207).
X Restart the engine. DISTRONIC PLUS DISTRONIC PLUS
inoperative inoperative DISTRONIC PLUS is faulty.
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 222). DISTRONIC
DISTRONIC
PLUS
PLUSand
and
SPEEDTRONIC inop‐
SPEEDTRONIC inop‐
erative erative DISTRONIC PLUS and SPEEDTRONIC are faulty. A warning tone
also sounds.
X Visit a qualified specialist workshop. Display
messages
341On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Rectify tyre pres‐
Rectify tyre pres‐
sure sure The tyre pressure is too low in at least one of the tyres, or the tyre
pressure difference between the wheels is too great.
X Check the tyre pressures at the next opportunity (Y page 433).
X If necessary, correct the tyre pressure.
X Restart the tyre pressure monitor (Y page 435).Check tyre(s)
Check tyre(s) The tyre pressure in one or more tyres has dropped significantly.
The wheel position is displayed in the multifunction display.
A warning tone also sounds.
G WARNING
Underinflated tyres pose the following risks:
R the tyres may burst, especially as the load and vehicle speed
increase
R the tyres may wear excessively and/or unevenly, which may
greatly impair tyre traction
R the driving characteristics, as well as steering and braking, may
be greatly impaired
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do so.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Check the tyres and, if necessary, follow the instructions for a
flat tyre (Y page 408).
X Check the tyre pressure (Y page 433).
X If necessary, correct the tyre pressure. Warning Warning
tyre
tyredefect
defect The tyre pressure in one or more tyres has dropped suddenly. The
wheel position is displayed in the multifunction display.
G WARNING
If you drive with a flat tyre, there is a risk of the following hazards:
R a flat tyre affects the ability to steer or brake the vehicle
R you could lose control of the vehicle
R continued driving with a flat tyre will cause excessive heat build-
up and possibly a fire
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do so.
X Secure the vehicle to prevent it from rolling away (Y page 207).
X Check the tyres and, if necessary, follow the instructions for a
flat tyre (Y page 408).344
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Tyre press. moni‐
Tyre press. moni‐
tor currently tor currently
unavailable unavailable Due to a source of radio interference, no signals can be received
from the wheel sensors. The tyre pressure monitor is temporarily
malfunctioning.
X Drive on.
The tyre pressure monitor restarts automatically as soon as the
cause has been rectified. Wheel sensor(s) Wheel sensor(s)
missing missing There is no signal from the tyre pressure sensor of one or several
wheels. The pressure of the affected tyre is not displayed in the
multifunction display.
X Have the faulty tyre pressure sensor replaced at a qualified spe-
cialist workshop. Tyre press. moni‐ Tyre press. moni‐
tor tor
inoperative
inoperative No
No
wheel sensors
wheel sensors The wheels fitted do not have suitable tyre pressure sensors. The
tyre pressure monitor is deactivated.
X Fit wheels with suitable tyre pressure sensors.
The tyre pressure monitor is activated automatically after driv-
ing for a few minutes. Tyre press. moni‐ Tyre press. moni‐
tor inoperative tor inoperative The tyre pressure monitor is faulty.
X Visit a qualified specialist workshop. Vehicle
Display messages
Possible causes/consequences and
M
MSolutions To start engine,
To start engine,
shift to either P shift to either P
or N or N You have attempted to start the engine with the transmission in
position
Ror D.
X Shift the transmission to position Por N. Auxiliary battery Auxiliary battery
malfunction malfunction The auxiliary battery for the transmission is no longer being
charged.
X Visit a qualified specialist workshop. Apply brake to Apply brake to
deselect Park (P) deselect Park (P)
position position You have attempted to move the transmission selector lever to
position
D,Ror Nwithout depressing the brake pedal.
X Depress the brake pedal. Display
messages
345On-board computer and displays Z