2012 MERCEDES-BENZ A-CLASS HATCHBACK brake

Display messages
Possible causes/consequences and
M
MSolutions b
Left-hand tail Left-hand tail
lamp/brake lamp lamp/brake lamp
or
Right-hand tail
Right-hand tail
lamp/brake lamp lamp/brake lamp The left or right-hand tail lamp/brake lamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 112).
or
X Visit a qualified specialist workshop. b
Left main beam Left main beam
or
Right main beam
Right main beam The left or right-hand main-beam headlamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 112).
or
X Visit a qualified specialist workshop. b
Number plate lamp Number plate lamp The left or right-hand licence plate lamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 112).
or
X Visit a qualified specialist workshop. b
Front Front
foglamp
foglamp left
left
or Front foglamp
Front foglamp
right
right The left-hand or right-hand front foglamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 112).
or
X Visit a qualified specialist workshop. b
Rear fog lamp Rear fog lamp The rear foglamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 112).
or
X Visit a qualified specialist workshop. b
Front Front
left
leftparking
parking
lamp
lamp orFront
Front
right parking lamp
right parking lamp The front left or front right parking lamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 112).
or
X Visit a qualified specialist workshop. b
Reversing light Reversing light The reversing lamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 112).
or
X Visit a qualified specialist workshop. Display
messages
241On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Speed Limit Assist
Speed Limit Assist
Currently unavail‐ Currently unavail‐
able See Owner's able See Owner's
Manual Manual Speed Limit Assist is deactivated and 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.
Speed Limit Assist is operational again. Speed Speed
Limit
LimitAssist:
Assist:
Unavailable in
Unavailable in
this country this country Speed Limit Assist is only available in certain countries.
X Drive on.
Speed Limit Assist is available again as soon as you drive into a
country in which its use is approved. Speed Speed
Limit
LimitAssist
Assist
inoperative
inoperative Speed Limit 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 179). 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 179). Radar sensor deac‐ Radar sensor deac‐
tivated See Own‐ tivated See Own‐
er's Manual er's Manual The radar sensor system is deactivated.
X Check whether or not the radar sensor system may be activated
(Y page 350).
X Switch on the radar sensor system (Y page 223).Radar sensor deac‐
Radar sensor deac‐
tivated tivated
autom.
autom.See
See
Owner's Manual
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 is deactivated automati-
cally.
If Blind Spot Assist was activated, it is no longer available. The
yellow 9indicator lamps also light up in the exterior mirrors.
X Drive on.
Blind Spot Assist is available again as soon as the vehicle is far
enough away from the radio telescope facility (Y page 350).246
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions DISTRONIC PLUS
DISTRONIC PLUS
inoperative inoperative DISTRONIC PLUS is faulty. Adaptive Brake Assist may also have
failed.
A warning tone also sounds.
X Visit a qualified specialist workshop. DISTRONIC PLUS DISTRONIC PLUS
inactive inactive 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
--- km/h --- km/h An activation condition for DISTRONIC PLUS is not fulfilled.
X Check the activation conditions for DISTRONIC PLUS
(Y page 175). 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. Cruise Cruise
control
control and
and
SPEEDTRONIC inop‐
SPEEDTRONIC inop‐
erative erative SPEEDTRONIC and cruise control are malfunctioning.
A warning tone also sounds.
X Visit a qualified specialist workshop. Limit
Limit
--- km/h --- km/h While depressing the accelerator pedal beyond the pressure point
(kickdown), SPEEDTRONIC cannot be activated. Cruise control
Cruise control
--- km/h --- km/h A condition for activating cruise control has not been met.
You have tried to store a speed below 30 km/h, for example.
X If conditions permit, drive faster than 30 km/h and store the
speed.
X Check the activation conditions for cruise control (Y page 169).120 km/h 120 km/h
Maximum speed Maximum speed
exceeded exceeded Only for certain countries: the maximum speed has been excee-
ded.
In addition, the multifunction display shows
120 km/h 120 km/h.
X Drive more slowly. 250
Display
messagesOn-board computer and displays

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 automatic transmission is no longer
being charged.
X Visit a qualified specialist workshop at the next opportunity.
X Until then, set the automatic transmission to position Pbefore
you switch off the engine.
X Before leaving the vehicle, apply the electric parking brake. Depress brake to
Depress brake to
start engine start engine You have attempted to start the engine with the transmission in
position Nwithout depressing the brake pedal.
X Depress the brake pedal. To shift out of P
To shift out of P
or N or N
depress brake and depress brake and
start engine start engine You have attempted to shift the transmission to position
Ror D
without starting the engine.
X Start the engine.
X Depress the brake pedal.
i It is only possible to shift the transmission from position
Pto
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 Pinto another transmission position when
the engine is running. 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
R,Nor Dwithout depressing the brake pedal.
X Depress the brake pedal. Risk of vehicle Risk of vehicle
rolling rolling
Transmission not Transmission not
in P in P The driver's door is open and the transmission is in position
R,N or
D.
A warning tone also sounds. X Shift the transmission to position P.
X Secure the vehicle against rolling away (Y page 162).252
Display messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Trans.
Trans.
oil
oiloverhea‐
overhea‐
ted Drive on with
ted Drive on with
care care AMG vehicles: the transmission oil has overheated.
Manual drive program
Mand the temporarily active manual drive
program are no longer available. The engine power output is
reduced.
X Allow the vehicle to cool down. 4matic currently 4matic currently
unavailable unavailable 4MATIC (permanent all-wheel drive) has overheated. The vehicle is
only driven by the front wheels.
X Drive on.
The airflow cools 4MATIC more quickly.
When the display message goes out, 4MATIC is available again and the vehicle is driven by all four wheels. 4matic inoperative
4matic inoperative 4MATIC is malfunctioning. The vehicle is only driven by the front
wheels.
X Visit a qualified specialist workshop. A The tailgate is open.
G WARNING
When the engine is running, exhaust gases can enter the vehicle
interior if the tailgate is open.
There is a risk of poisoning.
X Close the tailgate. ? The bonnet is open.
A warning tone also sounds.
G WARNING
The open bonnet may then block your view when the vehicle is in
motion.
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.
X Apply the electric parking brake.
X Close the bonnet. Active bonnet mal‐ Active bonnet mal‐
function See Own‐ function See Own‐
er's Manual er's Manual The active bonnet (pedestrian protection) is not active due to a
malfunction or because it has already been triggered.
X Visit a qualified specialist workshop. C At least one door is open. A warning tone also sounds.
X Close all doors. 254
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions j
Check trailer Check trailer
hitch lock hitch lock The trailer tow hitch is not correctly engaged.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Apply the electric parking brake.
X Engage the trailer coupling's ball coupling in the end position
(Y page 203).
Otherwise, the trailer may detach itself. Ð
Power Power
steering
steering mal‐
mal‐
function See Own‐
function See Own‐
er's Manual er's Manual The power steering assistance is faulty.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident. X Check whether you are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified
specialist workshop.
X If you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop. &
inoperative Bat‐ inoperative Bat‐
tery low tery low You have attempted to switch on the auxiliary heating or to acti-
vate a departure time using the on-board computer after operating
the auxiliary heating twice.
X Let the engine run for 10 seconds.
The auxiliary heating is operational again. The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on (Y page 134).
X Drive for a longer distance.
The battery is being charged. The auxiliary heating is operational
again as soon as the on-board electrical system voltage is suf-
ficient. &
inoperative inoperative
Refuel
Refuel
vehicle
vehicle There is too little fuel in the fuel tank. The auxiliary heating cannot
be switched on (Y page 134).
X Refuel at the nearest filling station. Display
messages
255On-board computer and displays Z

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