2012 MERCEDES-BENZ A CLASS Owners Manual

Display messages Possible causes/consequences and
M SolutionsVehicles with Becker
®
MAP PILOT: if the Becker ®
MAP PILOT is
not connected, the radar sensor system is deactivated automati-
cally.
Blind Spot Assist is not available.
X Connect the Becker ®
MAP PILOT; see the separate operating
instructions. Lane Keeping
Assist currently
unavailable See
Owner's Manual Lane Keeping 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.
R there are no lane markings for a longer period.
R the
lane markings are worn, dark or covered, e.g. by dirt or snow.
Once the causes listed above no longer apply, the display message
goes out.
Lane Keeping Assist 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 162).
X Clean the windscreen. Lane Keeping
Assist inoperative Lane Keeping Assist is faulty.
X
Visit a qualified specialist workshop. Blind Spot Assist
currently unavail‐
able See Owner's
Manual Blind Spot Assist is temporarily inoperative.
You

have established the electrical connection between the trailer
and your vehicle.
X Press a on the steering wheel to confirm the display mes-
sage.
Blind Spot Assist is deactivated while towing a trailer. Display messages
247
On-board computer and displays Z

Display messages Possible causes/consequences and
M SolutionsBlind Spot Assist is temporarily inoperative. Possible causes:
R
the sensors are dirty.
R the function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
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.
The yellow 9 indicator lamps also light up in the exterior mir-
rors.
Once
the causes listed above no longer apply, the display message
goes out.
Blind Spot Assist 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 162).
X Clean the sensors ( Y page 294).
X Restart the engine. Blind Spot Assist
inoperative Blind Spot Assist is faulty.
The yellow
9 indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Park Assist cancel‐
led The driver's door is open and the driver's seat belt has not been
fastened.
X
Repeat the parking process with the seat belt fastened and the
driver's door closed. You inadvertently touched the multifunction steering wheel while
steering intervention was active.
X
While steering intervention is active, make sure not to touch the
multifunction steering wheel. The vehicle has started to skid and ESP
®
has intervened.
X Use Active Parking Assist again later (Y page 186).248
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
M SolutionsPark Assist inoper‐
ative You have just carried out a large number of turning or parking
manoeuvres.
Active Parking Assist will become available again after approx-
imately ten minutes (
Y page 186).
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Switch off and restart the engine.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. PARKTRONIC is faulty.
X
Visit a qualified specialist workshop. DISTRONIC PLUS off DISTRONIC PLUS has been deactivated (
Y page 173). If it was
deactivated automatically, a warning tone also sounds. DISTRONIC PLUS
available again DISTRONIC PLUS is operational again after having been tempo-
rarily unavailable. You can now reactivate DISTRONIC PLUS
(Y page 173).
DISTRONIC PLUS cur‐
rently
unavailable
See Owner's Manual DISTRONIC PLUS is temporarily inoperative. Possible causes:
R
the function is impaired due to heavy rain or snow.
R the sensors in the radiator trim are dirty
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 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 162).
X Clean the sensors in the radiator trim (Y page 294).
X Restart the engine. Display messages
249
On-board computer and displays Z

Display messages Possible causes/consequences and
M SolutionsDISTRONIC PLUS
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
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
--- km/h An activation condition for DISTRONIC PLUS is not fulfilled.
X
Check the activation conditions for DISTRONIC PLUS
(Y page 175). DISTRONIC PLUS and
SPEEDTRONIC inop‐
erative DISTRONIC PLUS and SPEEDTRONIC are faulty. A warning tone
also sounds.
X
Visit a qualified specialist workshop. Cruise control and
SPEEDTRONIC inop‐
erative SPEEDTRONIC and cruise control are malfunctioning.
A warning tone also sounds.
X
Visit a qualified specialist workshop. Limit
--- km/h While depressing the accelerator pedal beyond the pressure point
(kickdown), SPEEDTRONIC cannot be activated.
Cruise control
--- 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
Maximum speed
exceeded Only for certain countries: the maximum speed has been excee-
ded.
In addition, the multifunction display shows
120 km/h.
X Drive more slowly.250
Display messages
On-board computer and displays

Tyres
Display messages Possible causes/consequences and
M SolutionsTyre pressure
Check tyres The tyre pressure loss warning system has detected a significant
loss in pressure.
A warning tone also sounds.
G WARNING
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.
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 against rolling away ( Y page 162).
X Check the tyres and, if necessary, follow the instructions for a
flat tyre (Y page 300).
X Check the tyre pressures and, if necessary, correct the tyre
pressure.
X Restart the tyre pressure loss warning system when the tyre
pressure is correct (Y page 323). Check tyre pres‐
sures
then restart Run
Flat Indicator The tyre pressure loss warning system generated a display mes-
sage and has not been restarted since.
X
Set the correct tyre pressure in all four tyres.
X Restart the tyre pressure loss warning system (Y page 323). Run Flat Indicator
inoperative The tyre pressure loss warning system is faulty.
X
Visit a qualified specialist workshop. Display messages
251
On-board computer and displays Z

Vehicle
Display messages Possible causes/consequences and
M SolutionsTo start engine,
shift to either P
or N You have attempted to start the engine with the transmission in
position R or D.
X
Shift the transmission to position P or N.Auxiliary battery
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 P before
you switch off the engine.
X Before leaving the vehicle, apply the electric parking brake. Depress brake to
start engine You have attempted to start the engine with the transmission in
position N without depressing the brake pedal.
X
Depress the brake pedal. To shift out of P
or N
depress brake and
start engine You have attempted to shift the transmission to position
R or 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 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. Apply brake to
deselect Park (P)
position You have attempted to move the transmission selector lever to
position R, N or D without depressing the brake pedal.
X
Depress the brake pedal. Risk of vehicle
rolling
Transmission not
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 messages
On-board computer and displays

Display messages Possible causes/consequences and
M SolutionsWithout changing
gear,
consult workshop You cannot change the transmission position due to a malfunction.
A warning tone also sounds.
If transmission position
D is selected:
X Drive to a qualified specialist workshop without shifting the
transmission from position D.
If transmission position R, N or P is selected:
X Consult a qualified specialist workshop. Only select Park
(P) when
vehicle
is station‐
ary The vehicle is moving.
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Shift the transmission to position P.Reversing not
poss.

Consult work‐
shop The automatic transmission is malfunctioning. You cannot drive in
reverse.
X
Visit a qualified specialist workshop. Transmission Mal‐
function The automatic transmission is malfunctioning.
X
Visit a qualified specialist workshop. Transmission mal‐
function Stop The automatic transmission is malfunctioning.
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 162).
X Consult a qualified specialist workshop. Stop vehicle Shift
to P Leave engine
running The automatic transmission has overheated.
X
Drive on carefully.
If the display message disappears, the automatic transmission
is available again.
If the display message continues to be displayed:
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 162).
X Wait until the automatic transmission has cooled off and the
display message goes out. Display messages
253On-board computer and displays Z

Display messages Possible causes/consequences and
M SolutionsTrans. oil overhea‐
ted Drive on with
care AMG vehicles: the transmission oil has overheated.
Manual drive program
M and 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
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 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‐
function See Own‐
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 messages
On-board computer and displays