2013 MERCEDES-BENZ CLA-CLASS warning light

Display messagesPossible causes/consequences and M SolutionsJ
Check brake fluid
levelThere is insufficient brake fluid in the brake fluid reservoir.
In addition, the red J warning lamp lights up in the instrument
cluster and a warning tone sounds.GWARNING
The braking efficiency may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.XSecure the vehicle against rolling away ( Y page 162).XConsult a qualified specialist workshop.XDo not top up the brake fluid. This does not correct the fault.#
Check brake pad
wearThe brake pads/linings have reached their wear limit.XVisit a qualified specialist workshop.PRE-SAFE
inoperative See
Owner's ManualImportant functions of PRE-SAFE ®
have failed. All other occupant
safety systems, e.g. airbags, remain available.XVisit a qualified specialist workshop immediately.Collision Preven‐
tion Assist Plus
currently unavail‐
able See Owner's
ManualCOLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R the radar sensor cover in the radiator trim is dirty.
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.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XSecure the vehicle against rolling away ( Y page 162).XClean the radar sensor cover in the radiator grille
( Y page 291).XRestart the engine.Display messages233On-board computer and displaysZProCarManuals.com

Display messagesPossible causes/consequences and M SolutionsýIf the symbol appears in the multifunction display, a seat belt
tongue has not been inserted in a rear seat belt buckle.GWARNING
A seat belt which is not worn correctly, or which has not been
engaged in the seat belt buckle correctly, cannot provide the
intended level of protection.
This poses an increased risk of injury.
XIf necessary, ask the occupants in the rear to fasten their seat
belts ( Y page 48).
Further information on the status indicator for the rear seat belts
( Y page 49).
6
Restraint sys. mal‐
function Consult
workshopThere is a malfunction in the SRS (Supplemental Restraint Sys-
tem). The 6 warning lamp also lights up in the instrument clus-
ter.GWARNING
The airbags or belt tensioners may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury.
XVisit a qualified specialist workshop.
Further information on occupant safety ( Y page 40).
6
Front left malfunc‐
tion Consult work‐
shop  or Front
right malfunction
Consult workshopSRS has malfunctioned at the front on the left or right. The 6
warning lamp also lights up in the instrument cluster.GWARNING
The airbags or belt tensioners may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury.
XVisit a qualified specialist workshop.Display messages235On-board computer and displaysZProCarManuals.com

Display messagesPossible causes/consequences and M Solutions6
Rear left-hand
side malfunction
Consult workshop  
or  Rear right-hand
side malfunction
Consult workshopSRS has malfunctioned at the rear on the left or right. The 6
warning lamp also lights up in the instrument cluster.GWARNING
The airbags or belt tensioners may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury.
XVisit a qualified specialist workshop.6
Left windowbag mal‐
function Consult
workshop  or Right
windowbag malfunc‐
tion Consult work‐
shopThere is a malfunction in the left-hand and/or right-hand window-
bag. The 6 warning lamp also lights up in the instrument clus-
ter.GWARNING
The left or right windowbag may either be triggered unintentionally
or, in the event of an accident, may not be triggered.
This poses an increased risk of injury.
XVisit a qualified specialist workshop.
Lights
i Display messages about LEDs:
This display message will only appear if all the LEDs have failed.
Display messagesPossible causes/consequences and M Solutionsb
Left cornering
light  or Right cor‐
nering lightThe left or right-hand cornering light is faulty.XCheck whether you are permitted to replace the bulb yourself
( Y page 114).
or
XVisit a qualified specialist workshop.b
Left dipped beam  
or  Right dipped
beamThe left or right-hand dipped-beam headlamp is faulty.XCheck whether you are permitted to replace the bulb yourself
( Y page 114).
or
XVisit a qualified specialist workshop.236Display messagesOn-board computer and displays
ProCarManuals.com

Display messagesPossible causes/consequences and M Solutionsb
Reversing lightThe reversing lamp is faulty.XCheck whether you are permitted to replace the bulb yourself
( Y page 114).
or
XVisit a qualified specialist workshop.b
Left tail lamp  or 
Right tail lamp The left or right-hand tail lamp is faulty.XCheck whether you are permitted to replace the bulb yourself
( Y page 114).
or
XVisit a qualified specialist workshop.b
Left daytime driv‐
ing lamp  or Right
daytime driving
lampThe left-hand or right-hand daytime driving lamp is faulty.XCheck whether you are permitted to replace the bulb yourself
( Y page 114).
or
XVisit a qualified specialist workshop.b
Intell. Light Sys‐
tem inoperativeThe Intelligent Light System is faulty. The lights remain available
without the Intelligent Light System.XVisit a qualified specialist workshop.b
Malfunction See
Owner's ManualThe exterior lighting is faulty.XVisit a qualified specialist workshop.Vehicles with trailer tow hitch: a fuse may have blown.XCheck the fuses ( Y page 312).XIf necessary, replace the blown fuse. Observe the warning notes
as you do so.
If the display message continues to be displayed:
XVisit a qualified specialist workshop.b
AUTO lights inoper‐
ativeThe light sensor is faulty.XVisit a qualified specialist workshop.b
Switch off lightsThe lights are still switched on when you leave the vehicle. A
warning tone also sounds.XTurn the light switch to Ã.Display messages239On-board computer and displaysZProCarManuals.com

Warning and indicator lamps in the instrument cluster
Seat belts
ProblemPossible causes/consequences and M Solutionsü
Only for certain coun-
tries: the red seat belt
warning lamp lights up
for six seconds after
the engine starts.The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.XFasten your seat belt ( Y page 46).ü
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.The driver's seat belt is not fastened.XFasten your seat belt ( Y page 46).
The warning tone ceases.ü
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.The driver or front passenger has not fastened their seat belt.XFasten your seat belt ( Y page 46).
The warning lamp goes out.There are objects on the front-passenger seat.XRemove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out.ü
The red seat belt warn-
ing lamp flashes and an
intermittent audible
warning sounds.The driver or front passenger has not fastened their seat belt. At
the same time, you are driving faster than 25 km/h or have briefly
driven faster than 25 km/h.XFasten your seat belt ( Y page 46).
The warning lamp goes out and the intermittent warning tone
ceases.There are objects on the front-passenger seat. At the same time,
you are driving faster than 25 km/h or have briefly driven faster
than 25 km/h.XRemove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out and the intermittent warning tone
ceases.Warning and indicator lamps in the instrument cluster255On-board computer and displaysZProCarManuals.com

Safety systemsProblemPossible causes/consequences and M SolutionsJ
The red brake system
warning lamp is lit while
the engine is running. A
warning tone also
sounds.There is insufficient brake fluid in the brake fluid reservoir.GWARNING
The braking efficiency may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.XSecure the vehicle against rolling away ( Y page 162).XDo not top up the brake fluid. Topping up will not rectify the
fault.XConsult a qualified specialist workshop.XObserve the additional display messages in the multifunction
display.!
The yellow ABS warning
lamp is lit while the
engine is running.ABS (Anti-lock Brake System) has been deactivated due to a fault.
Therefore, BAS (Brake Assist), COLLISION PREVENTION ASSIST,
COLLISION PREVENTION ASSIST PLUS, ESP ®
(Electronic Stability
Program), PRE-SAFE ®
, the HOLD function, hill start assist, the
adaptive brake lights and ESP ®
trailer stabilisation, for example,
are also deactivated.
ATTENTION ASSIST is deactivated.GWARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit 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 be unavailable.
256Warning and indicator lamps in the instrument clusterOn-board computer and displays
ProCarManuals.com

ProblemPossible causes/consequences and M Solutions!
The yellow ABS warning
lamp is lit while the
engine is running.ABS is temporarily unavailable. Therefore, BAS, COLLISION PRE-
VENTION ASSIST, COLLISION PREVENTION ASSIST PLUS, ESP ®
,
EBD (electronic brake force distribution), PRE-SAFE ®
, the HOLD
function, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation, for example, are also deactivated.
Possible causes:
R self-diagnosis is not yet complete.
R the on-board voltage may be insufficient.
ATTENTION ASSIST is deactivated.GWARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is a risk of an accident.
XCarefully 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:
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.Warning and indicator lamps in the instrument cluster257On-board computer and displaysZProCarManuals.com

ProblemPossible causes/consequences and M Solutions!
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds.EBD is faulty. Therefore, ABS, BAS, COLLISION PREVENTION
ASSIST, COLLISION PREVENTION ASSIST PLUS, ESP ®
,
PRE-SAFE ®
, the HOLD function, hill start assist, the adaptive brake
lights and ESP ®
trailer stabilisation, for example, are not available
either.
ATTENTION ASSIST is deactivated.GWARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.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.ABS and ESP ®
are malfunctioning. Therefore, BAS, COLLISION
PREVENTION ASSIST, COLLISION PREVENTION ASSIST PLUS,
EBD, PRE-SAFE ®
, the HOLD function, hill start assist; the adaptive
brake lights and ESP ®
trailer stabilisation, for example, are not
available either.
ATTENTION ASSIST is deactivated.GWARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.258Warning and indicator lamps in the instrument clusterOn-board computer and displays
ProCarManuals.com