air condition MERCEDES-BENZ A-CLASS HATCHBACK 2012 Owner's Manual

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos- sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 24). Important safety notes
G
WARNING
Operating the integrated information systems and communications equipment in the vehicle
while driving will distract you from traffic con-
ditions. You could then lose control of the
vehicle. There is a risk of an accident.
Only operate these devices if road traffic con-
ditions permit. If you are unsure about the
surrounding conditions, pull over to a safe
location and make entries only while the vehi-
cle is stationary. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognise function
restrictions relevant to safety. The operating
safety of your vehicle may be impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
You must observe the legal requirements for
the country in which you are currently driving when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the mul- tifunction display. You should therefore make
sure your vehicle is operating safely at all times. Otherwise, a vehicle that is not oper-
ating safely may cause an accident.
For an overview, see the instrument panel
illustration (Y
page 30). Displays and operation
Instrument cluster lighting
The lighting in the instrument cluster, in the
displays and the controls in the vehicle inte-
rior can be adjusted using the brightness con- trol knob.
The brightness control knob is on the bottom
left of the instrument cluster (Y page 30).
X Turn the brightness control knob clockwise
or anti-clockwise.
If the light switch is set to Ã,Tor
L, the brightness is dependant upon
the brightness of the ambient light.
i The light sensor in the instrument cluster
automatically controls the brightness of
the multifunction display.
In daylight, the displays in the instrument
cluster are not illuminated. Coolant temperature gauge
The coolant temperature gauge is in the
instrument cluster on the right-hand side.
The reading may rise up to 120 † below nor-
mal driving conditions if the coolant has been filled correctly.
At high outside temperatures and when driv-
ing uphill, the coolant temperature may rise
to the end of the scale. Rev counter
! Do not drive in the overrevving range.
Doing so will damage the engine.
The red band in the rev counter indicates the
engine's overrevving range. 208
Displays and operationOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions J
Brake immediately Brake immediately Vehicles with manual transmission: a malfunction has occurred
while the HOLD function was activated.
A tone may also sound at regular intervals. If you attempt to lock the vehicle, the tone becomes louder.
You cannot start the engine.
X Paying attention to the traffic situation, immediately depress the
brake pedal firmly and hold until the display message disap-
pears.
X Secure the vehicle against rolling away (Y page 162).
You can restart the engine. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
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 Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the fault. #
Check brake pad Check brake pad
wear wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. PRE-SAFE
PRE-SAFE
inoperative See inoperative See
Owner's Manual Owner's Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. 236
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions PRE-SAFE
PRE-SAFE
Functions cur‐ Functions cur‐
rently rently
limited
limited See
See
Owner's Manual
Owner's Manual Adaptive Brake Assist 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 AMG vehicles: ESP ®
is deactivated.
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.
Adaptive Brake 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 radar sensor cover in the radiator grille (Y page 294).
X Restart the engine.
X AMG vehicles: reactivate ESP ®
(Y page 66). PRE-SAFE PRE-SAFE
Functions limited Functions limited
See Owner's Manual See Owner's Manual Adaptive Brake Assist is faulty. The distance warning signal may
also have failed.
X Visit a qualified specialist workshop. ü If the symbol appears in the multifunction display, a seat belt
tongue has been inserted into a rear seat belt buckle.
Further information on the status indicator for the rear seat belts
(Y page 49). ý If the symbol appears in the multifunction display, a seat belt
tongue has not been inserted in a rear seat belt buckle.
G WARNING
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.
X If necessary, ask the occupants in the rear to fasten their seat
belts (Y page 47).
Further information on the status indicator for the rear seat belts
(Y page 49). Display
messages
237On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions ?
Coolant Stop vehi‐ Coolant Stop vehi‐
cle Switch engine cle Switch engine
off off The coolant is too hot.
A warning tone also sounds.
G WARNING
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.
There is a risk of injury.
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 Wait until the engine has cooled down.
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 display message goes out
and the coolant temperature is below 120 †. The engine may
otherwise be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant level, the coolant temperature may rise to 120 †. # The battery is not being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Open the bonnet.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is OK: X Visit a qualified specialist workshop immediately. 244
Display
messagesOn-board computer and displays

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 Vehicles with Becker
®
MAP PILOT: if the Becker ®
MAP PILOT is not
connected, the radar sensor system is deactivated automatically.
Blind Spot Assist is not available.
X Connect the Becker ®
MAP PILOT; see the separate operating
instructions. Lane Keeping
Lane Keeping
Assist currently Assist currently
unavailable See unavailable See
Owner's Manual 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 Lane Keeping
Assist inoperative Assist inoperative Lane Keeping Assist is faulty.
X Visit a qualified specialist workshop. Blind Spot Assist
Blind Spot Assist
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual Blind Spot Assist is temporarily inoperative.
You have established the electrical connection between the trailer
and your vehicle.
X Press aon the steering wheel to confirm the display mes-
sage.
Blind Spot Assist is deactivated while towing a trailer. Display
messages
247On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Blind 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 9indicator 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 Blind Spot Assist
inoperative inoperative Blind Spot Assist is faulty.
The yellow
9indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Park Park
Assist
Assist cancel‐
cancel‐
led
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
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Park
Park
Assist
Assist inoper‐
inoper‐
ative
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 off DISTRONIC PLUS has been deactivated (Y
page 173). If it was
deactivated automatically, a warning tone also sounds. DISTRONIC PLUS
DISTRONIC PLUS
available again available again DISTRONIC PLUS is operational again after having been tempo-
rarily unavailable. You can now reactivate DISTRONIC PLUS
(Y
page 173). DISTRONIC DISTRONIC
PLUS
PLUScur‐
cur‐
rently
rently unavailable
unavailable
See Owner's Manual
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
249On-board computer and displays Z

Tyres
Display messages
Possible causes/consequences and
M
MSolutions Tyre pressure
Tyre pressure
Check tyres 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‐ Check tyre pres‐
sures sures
then restart Run then restart Run
Flat Indicator 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 Run
Flat
Flat Indicator
Indicator
inoperative
inoperative The tyre pressure loss warning system is faulty.
X Visit a qualified specialist workshop. Display
messages
251On-board computer and displays Z

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