2012 MERCEDES-BENZ A-CLASS HATCHBACK display

Safety systems
Problem
Possible causes/consequences and
M
MSolutions J
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.
G WARNING
The 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 162).
X Do not top up the brake fluid. Topping up will not rectify the fault.
X Consult a qualified specialist workshop.
X Observe 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.
BAS (Brake Assist), COLLISION PREVENTION ASSIST, ESP ®
(Elec-
tronic Stability Program), PRE ‑SAFE®
, the HOLD function, hill start
assist, the adaptive brake lights and ESP ®
trailer stabilisation are
also therefore deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
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.
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 be unavailable. 258
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions !
The yellow ABS warning
lamp is lit while the
engine is running. ABS is temporarily unavailable. Therefore, BAS, COLLISION PRE-
VENTION ASSIST, 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 deacti-
vated.
Possible causes:
R Self-diagnosis is not yet complete.
R the on-board voltage may be insufficient
ATTENTION ASSIST is deactivated.
G WARNING
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.
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. Warning and indicator lamps in the instrument cluster
259On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions !
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, 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.
G WARNING
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.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit 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, EBD, PRE ‑SAFE®
, the HOLD function, hill
start assist, the adaptive brake lights and ESP ®
trailer stabilisa-
tion, for example, are not available either.
ATTENTION ASSIST is deactivated.
G WARNING
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.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 260
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions ÷
The yellow ESP
®
warn-
ing lamp flashes while
the vehicle is in motion. 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 Accelerate more gently while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
For exceptions, see: (Y page 65).å
The yellow ESP
®
OFF
warning lamp is lit while the engine is running. ESP
®
and ESP ®
trailer stabilisation are deactivated. ESP ®
will not
stabilise the vehicle if it starts to skid or if a wheel starts to spin.
G WARNING
If ESP ®
is deactivated, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Reactivate ESP ®
.
For exceptions, see: (Y page 65).
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. M
AMG vehicles only:
The yellow SPORT han-
dling mode warning
lamp is lit while the
engine is running.
SPORT handling mode is activated.
G WARNING
When SPORT handling mode is switched on, ESP ®
is unable to
stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Only switch on SPORT handling mode in certain situations
(Y page 66). Warning and indicator lamps in the instrument cluster
261On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions ֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, COLLISION PREVENTION ASSIST, PRE ‑SAFE®
, the
HOLD function, hill start assist, the adaptive brake lights and
ESP ®
trailer stabilisation are not available due to a malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance may thus 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.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. ֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist and
ESP ®
trailer stabilisation are temporarily unavailable.
The adaptive brake lights and COLLISION PREVENTION ASSIST
may also have failed.
ATTENTION ASSIST is deactivated.
Self-diagnosis is not yet complete.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance may thus 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.
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. 262
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions !
The red indicator lamp
for the electric parking
brake flashes or is lit
and/or the yellow
warning lamp for the
electric parking brake
is lit. X
Observe the additional display messages in the multifunction
display. 6
The red SRS warning
lamp is lit while the
engine is running.
There is a malfunction in the SRS (Supplemental Restraint Sys-
tem).
G WARNING
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. X Drive on carefully.
X Have SRS checked at a qualified specialist workshop immedi-
ately.
For further information about the Supplemental Restraint System, see (Y page 41). Warning and indicator lamps in the instrument cluster
263On-board computer and displays Z

Engine
Problem
Possible causes/consequences and
M
MSolutions ;
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.
X Have 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).
X Start 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.
X Refuel 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.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 162).
X Consult a qualified specialist workshop. 264
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions ?
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 malfunc-
tioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 162).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant (Y page 288).
Observe the warning notes as you do so.
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the coolant temperature is
below 120 †. The engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid 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.
G WARNING
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.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 162).Warning and indicator lamps in the instrument cluster
265On-board computer and displays Z