2013 MERCEDES-BENZ CLA ECU

Display messagesPossible causes/consequences and M SolutionsCheck tyresThe tyre pressure in one or more tyres has dropped significantly.
The wheel position is displayed in the multifunction display.
A warning tone also sounds.GWARNING
With tyre pressures which are too low, there is a risk of the fol-
lowing hazards:
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.
XStop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do
so.XSecure the vehicle against rolling away ( Y page 162).XCheck the tyres and, if necessary, follow the instructions for a
flat tyre ( Y page 298).XCheck the tyre pressure ( Y page 322).XIf necessary, correct the tyre pressure.Caution, tyre
defectThe tyre pressure in one or more tyres has dropped suddenly. The
wheel position is displayed in the multifunction display.GWARNING
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.
XStop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do
so.XSecure the vehicle against rolling away ( Y page 162).XCheck the tyres and, if necessary, follow the instructions for a
flat tyre ( Y page 298).Display messages249On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsTo shift out of P
or N
depress brake and
start engineYou have attempted to shift the transmission to position R or D
without starting the engine.XStart the engine.XDepress the brake pedal.
i It is only possible to shift the transmission from position P to
the desired position if you depress the brake pedal. Only then
can the parking lock be deactivated. If you do not depress the
brake pedal, the DIRECT SELECT lever can still be moved but
the parking lock remains engaged.
i At transmission fluid temperatures below Ò20 † you can only
shift out of position P into another transmission position when
the engine is running.
Depress brake to
shift out of posi‐
tion PYou have attempted to move the transmission selector lever to
position R, N or D without depressing the brake pedal.XDepress the brake pedal.Risk of vehicle
rolling
Transmission not
in PThe driver's door is open and the transmission is in position R, N
or D.
A warning tone also sounds.XShift the transmission to position P.XSecure the vehicle against rolling away ( Y page 162).Without changing
gear,
consult workshopYou cannot change the transmission position due to a malfunction.
A warning tone also sounds.
If transmission position D is selected:XDrive to a qualified specialist workshop without shifting the
transmission from position D.
If transmission position R, N or P is selected:
XConsult a qualified specialist workshop.Only select Park
(P) when
vehicle is station‐
aryThe vehicle is moving.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XShift the transmission to position P.Reversing not
poss. Consult work‐
shopThe automatic transmission is malfunctioning. You cannot drive in
reverse.XVisit a qualified specialist workshop.Display messages251On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsTransmission mal‐
functionThe automatic transmission is malfunctioning.XVisit a qualified specialist workshop.Transmission mal‐
function StopThe automatic transmission is malfunctioning.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).XConsult a qualified specialist workshop.Stop vehicle Shift
to P Leave engine
runningThe automatic transmission has overheated.XDrive on carefully.
If the display message disappears, the automatic transmission
is available again.
If the display message continues to be displayed:
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).XWait until the automatic transmission has cooled off and the
display message goes out.NThe boot lid is open.XClose the boot lid.MThe bonnet is open.
A warning tone also sounds.GWARNING
The open bonnet may then block your view when the vehicle is in
motion.
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.XApply the electric parking brake.XClose the bonnet.Active bonnet mal‐
function See Own‐
er's ManualThe active bonnet (pedestrian protection) is not active due to a
malfunction or because it has already been triggered.XVisit a qualified specialist workshop.CAt least one door is open. A warning tone also sounds.XClose all doors.252Display messagesOn-board computer and displays

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 displaysZ

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

EngineProblemPossible causes/consequences and M Solutions;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running.There may be a fault, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engine may
be running in emergency mode.XHave the vehicle checked as soon as possible at a qualified
specialist workshop.Vehicles with a diesel engine: the fuel tank has been run dry
( Y page 161).XStart the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emer-
gency running mode is cancelled. The vehicle need not be
checked.æ
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated when the fuel level
drops into the reserve range.XRefuel at the nearest filling station.?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the
start of the scale.The temperature sensor for the coolant temperature gauge is
faulty.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.XStop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.XSecure the vehicle against rolling away ( Y page 162).XConsult a qualified specialist workshop.262Warning and indicator lamps in the instrument clusterOn-board computer and displays

ProblemPossible causes/consequences and M Solutions?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator
may be blocked or the electric engine radiator fan may be mal-
functioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.XObserve the additional display messages in the multifunction
display.XStop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.XSecure the vehicle against rolling away ( Y page 162).XLeave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.XCheck the coolant level and top up the coolant ( Y page 285).
Observe the warning notes as you do so.XIf you have to top up the coolant frequently, have the engine
cooling system checked.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.XDo not start the engine again until the coolant temperature is
below 120 †. The engine may otherwise be damaged.XDrive to the nearest qualified specialist workshop.XAvoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic.?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.The coolant temperature has exceeded 120 †. The airflow to the
engine radiator may be blocked or the coolant level may be too
low.GWARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine
is overheated can cause some fluids which may have leaked into
the engine compartment to catch fire.
Steam from an overheated engine can cause serious burns which
can occur just by opening the bonnet.
This poses a risk of injury.
XObserve the additional display messages in the multifunction
display.XStop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.XSecure the vehicle against rolling away ( Y page 162).Warning and indicator lamps in the instrument cluster263On-board computer and displaysZ

TyresProblemPossible causes/consequences and M Solutionsh
The yellow tyre pres-
sure monitor warning
lamp (pressure loss/
malfunction) is lit.The tyre pressure monitor has detected a loss of pressure in at
least one of the tyres.GWARNING
With tyre pressures which are too low, there is a risk of the fol-
lowing hazards:
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.
XStop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do
so.XSecure the vehicle against rolling away ( Y page 162).XObserve the additional display messages in the multifunction
display.XCheck the tyres and, if necessary, follow the instructions for a
flat tyre ( Y page 298).XCheck the tyre pressure ( Y page 322).XIf necessary, correct the tyre pressure.h
The yellow tyre pres-
sure monitor warning
lamp (pressure loss/
malfunction) flashes for
approximately one
minute and then
remains lit.The tyre pressure monitor is faulty.GWARNING
The system is possibly unable to recognise or register low tyre
pressure.
There is a risk of an accident.
XObserve the additional display messages in the multifunction
display.XVisit a qualified specialist workshop.Warning and indicator lamps in the instrument cluster265On-board computer and displaysZ