warning lights MERCEDES-BENZ A CLASS 2012 Owner's Guide

Storing the current speed and calling up
the last stored speed
G
WARNING
If you call up a stored speed and this is dif-
ferent from the current speed, the vehicle
accelerates or brakes. If you do not know
what the stored speed is, the vehicle may
accelerate or brake unexpectedly. There is a
risk of an accident.
Take the traffic conditions into account
before calling up the stored speed. If you do
not know what the stored speed is, store the
desired speed again.
X Briefly pull the cruise control lever towards
you =.
X Remove your foot from the accelerator
pedal.
The first time cruise control is activated, it
stores the current speed or regulates the
speed of the vehicle to the previously
stored speed.
Setting a speed Keep in mind that it may take a brief moment
until
the vehicle has accelerated or braked to
the set speed.
X Press the cruise control lever up : for a
higher

speed or down ? for a lower speed.
X Keep the cruise control lever pressed until
the desired speed is reached.
X Release the cruise control lever.
The new speed is stored.
X To adjust the set speed in 1 km/h incre-
ments: briefly press the cruise control
lever up : or down ? to the pressure
point.
The

last stored speed increases or decrea-
ses in 1 km/h increments.
X To adjust the set speed in 10 km/h
increments:

press the cruise control lever
briefly up : or down ? beyond the pres-
sure point.
The last stored speed increases or decrea-
ses in 10 km/h increments. i
Cruise control is not deactivated if you
depress the accelerator pedal. For exam-
ple, if you accelerate briefly to overtake,
cruise control adjusts the vehicle's speed
to

the last speed stored after you have fin-
ished overtaking.
Deactivating cruise control There are several ways to deactivate cruise
control:
X
Briefly press the cruise control lever for-
wards B.
or
X Brake
or
X Briefly press the cruise control lever in the
direction of arrow A.
Variable SPEEDTRONIC is selected. LIM
indicator

lamp ; in the cruise control lever
lights up.
Cruise control is automatically deactivated if:
R you engage the electric parking brake.
R you are driving at less than

30 km/h.
R ESP ®
intervenes or you deactivate ESP ®
R while driving a vehicle with manual trans-
mission, you shift into neutral or depress
the clutch pedal for longer than six sec-
onds.
R on vehicles with manual transmission, you
shift to a gear that is too high, and as a
result the engine speed is too low.
R on vehicles with automatic transmission,
you shift into position N while driving.
If cruise control is deactivated, you will hear
a warning tone. You will see the Cruise
control off message in the multifunction
display for approximately five seconds.
i The last speed stored is cleared when you
switch off the engine. 170
Driving systems
Driving and parking

Other vehicles changing lane
DISTRONIC PLUS has not detected the vehi-
cle
cutting in yet. The distance to this vehicle
will be too short.
Narrow vehicles DISTRONIC PLUS has not yet detected the
vehicle in front on the edge of the carriage-
way, because of its narrow width. The dis-
tance

to the vehicle in front will be too short.
Obstructions and stationary vehicles DISTRONIC PLUS does not brake for obsta-
cles

or stationary vehicles. If, for example, the detected vehicle turns a corner and reveals
an

obstacle or stationary vehicle, DISTRONIC
PLUS will not brake for these.
Crossing vehicles DISTRONIC PLUS may detect vehicles that
are

crossing your lane by mistake. Activating
DISTRONIC PLUS at traffic lights with cross-
ing traffic, for example, could cause your vehi-
cle to pull away unintentionally. HOLD function
Important safety notes G
WARNING
When leaving the vehicle, it can still roll away
despite
being braked by the HOLD function if:
R there is a malfunction in the system or in
the voltage supply
R the HOLD function is deactivated by the
accelerator pedal being depressed, e.g. by
a vehicle occupant
R the electrical system in the engine com-
partment, the battery or the fuses are tam-
pered with
R the battery is disconnected
There is a risk of an accident.
Before leaving the vehicle, always deactivate
the HOLD function and secure the vehicle
from rolling away. Driving systems
179
Driving and parking Z

Problems with PARKTRONIC
Problem Possible causes/consequences and
M SolutionsOnly the red segments
in the PARKTRONIC
warning
displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is deacti-
vated after approx-
imately five seconds,
and the indicator lamp
in the PARKTRONIC
button lights up. PARKTRONIC has malfunctioned and has switched off.
X
If problems persist, have PARKTRONIC checked at a qualified
specialist workshop. Only the red segments
in the PARKTRONIC
warning

displays are lit.
PARKTRONIC is deacti-
vated after approx-
imately five seconds. The PARKTRONIC sensors are dirty or there is interference.
X
Clean the PARKTRONIC sensors ( Y page 294).
X Switch the ignition back on. The problem may be caused by an external source of radio or
ultrasound waves.
X
See if PARKTRONIC functions in a different location. Active Parking Assist
Important safety notes Active Parking Assist is only an aid. It is not a
substitute

for your attention to the immediate
surroundings. The responsibility for safe
manoeuvring and parking remains with you.
Make sure that there are no persons, animals
or objects in range while manoeuvring and
parking. G
WARNING
The vehicle will veer out when parking and can
take
you onto sections of the oncoming lane.
As a result, you may collide with other road
users. There is a risk of an accident.
When parking, pay attention to other road
users. Stop the vehicle if necessary or cancel
the Active Parking Assist parking procedure.
! If unavoidable, you should drive over
obstacles such as kerbs slowly and not at a sharp angle. Otherwise, you may damage
the wheels or tyres.
Active

Parking Assist may also display spaces
not suitable for parking, e.g.:
R parking or stopping prohibitions
R in front of driveways or entrances and exits
R unsuitable surfaces
Parking tips:
R on narrow roads, drive as closely as possi-
ble past the parking space.
R parking spaces that are littered, overgrown
or partially occupied by trailer drawbars
might be identified incorrectly or not at all.
R snowfall or heavy rain may lead to a parking
space being measured inaccurately.
R pay attention to the PARKTRONIC
(Y page 184) warning messages during the
parking procedure. 186
Driving systems
Driving and parking

10 km/h when exiting a parking space.
Otherwise, Active Parking Assist will be
cancelled.
X Stop when PARKTRONIC sounds the con-
tinuous warning tone, if not before.
X Vehicles with manual transmission:
shift to first or reverse gear as required
while the vehicle is stationary.
Vehicles with automatic transmission:
shift
to position D or R as required while the
vehicle is stationary.
Active Parking Assist immediately steers in
the other direction. The Park Assist
active Accelerate and brake
Observe surroundings message appears
in the multifunction display.
i You will achieve the best results by wait-
ing

for the steering procedure to complete
before pulling away.
If you reverse after activation, the steering
wheel is moved to the straight-ahead posi-
tion.
X Drive forwards or reverse the vehicle, being
ready to brake at all times.
X Stop as soon as PARKTRONIC sounds the
continuous warning tone, if not before.
X Drive forwards and reverse as prompted by
the

PARKTRONIC warning displays, several
times if necessary.
Once you have exited the parking space com-
pletely, the steering wheel is moved to the
straight-ahead position. You hear a tone and
the Park Assist switched off message
appears

in the multifunction display. You will
then have to steer and merge into traffic on
your own. PARKTRONIC is still available. Cancelling Active Parking Assist You can cancel Active Parking Assist at any
time.
X
Stop the movement of the multifunction
steering wheel or steer yourself.
Active Parking Assist will be cancelled at
once. The Park Assist cancelled mes-
sage appears in the multifunction display.
or
X Press the PARKTRONIC button on the
centre console

(Y page 185).
PARKTRONIC is switched off and Active
Parking Assist is immediately cancelled.
The Park Assist cancelled message
appears in the multifunction display.
Active Parking Assist is cancelled automati-
cally if:
R you engage the electric parking brake.
R parking using Active Parking Assist is no
longer possible.
R you are driving faster than 10 km/h.
R a

wheel spins and ESP ®
intervenes or fails.
The ÷ warning lamp lights up in the
instrument cluster.
A warning tone sounds. The parking space
symbol disappears and the multifunction dis-
play shows the Park Assist cancelled
message.
When Active Parking Assist is cancelled, you
must steer again yourself.
If a system malfunction occurs, the vehicle is
braked to a standstill. To drive on, depress the
accelerator again.
Towing a trailer For vehicles with a trailer tow hitch, the min-
imum required length for parking spaces is
slightly increased.
If you have attached a trailer to your vehicle,
you should not use Active Parking Assist.
Once

the electrical connection is established
between your vehicle and the trailer, Active
Parking Assist is no longer available. PARK-
TRONIC is deactivated for the rear area. 190
Driving systems
Driving and parking

Indicator and warning display
Blind
Spot Assist is not active at speeds below
approximately 30 km/h. Vehicles in the mon-
itoring range are then not indicated. :
Yellow indicator lamp/red warning lamp
If Blind Spot Assist is switched on, indicator
lamp : in the exterior mirrors lights up yel-
low up to a speed of

30 km/h. At speeds
above 30 km/h, the indicator lamp goes out
and Blind Spot Assist is operational.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
30 km/h, warning lamp : on the corre-
sponding side lights up in red. This warning
always occurs when a vehicle enters the blind
spot monitoring range from behind or from
the side. When you overtake a vehicle, the
warning only occurs if the difference in speed
is less than 12 km/h.
The yellow indicator lamp goes out if reverse
gear is engaged. Blind Spot Assist is then
deactivated.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp : flashes. If
the turn signal remains on, detected vehicles
are indicated by the flashing of red warning
lamp :. There are no further warning tones. Activating Blind Spot Assist
X
Make sure that the radar sensor system
(Y page 223) and Blind Spot Assist
(Y page

219) are activated in the on-board
computer.
X Turn the key to position 2 in the ignition
lock.
Warning lamps : in the exterior mirrors
light up red for approximately
1.5 seconds

and then turn yellow.
Towing a trailer
If
you attach a trailer, make sure that you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Blind Spot Assist is then
deactivated. The indicator lamp lights up yel-
low in the exterior mirrors and the Blind
Spot Assist currently unavailable
See Owner's Manual message appears in
the multifunction display.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, switch off Blind Spot Assist if:
R the key is in position 2 in the ignition
lock.
R the engine is not running.
R the electrical connection to the trailer
has been established.
Lane Keeping Assist General notes
Lane Keeping Assist monitors the area in
front

of your vehicle by means of a camera at
the top of the windscreen. Lane Keeping
Assist detects lane markings on the road and
warns you before you leave your lane unin-
tentionally. Driving systems
199
Driving and parking Z

Speed Limit Assist
Displaying Speed Limit Assist
X
Press the = or ; button on the steer-
ing wheel to select the Assist. menu.
X Press the 9 or : button to select
Speed Limit Assist.
X Press the a button.
Under certain conditions, detected speed
limits are shown in the multifunction dis-
play

(Y page 196).
Activating/deactivating the Speed Limit
Assist message function
X Press the =
or ; button on the steer-
ing wheel to select the Assist. menu.
X Press the 9 or : button to select
Speed Limit Assist.
X Press the a button.
The multifunction display shows Speed
Limit Assist.
X Press the : button.
The current selection is displayed.
X To activate or deactivate: press a.
If
the Speed Limit Assist message function
is activated, a detected speed limit is auto-
matically displayed for five seconds. Other
items in the multifunction display are not
shown during this time.
When Speed Limit Assist is operational and
the message function is activated, the
assistance graphic shows the Ä sym-
bol.
Deactivating/activating ESP ®i
Observe
the "Important safety notes" sec-
tion in the description of ESP ( Y page 65).G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilises the vehicle. There is an increased risk
of skidding and an accident.
Only

deactivate ESP ®
in the situations descri-
bed in the following. It may be best to deactivate ESP
®
in the fol-
lowing situations:
R when using snow chains
R in deep snow
R on sand or gravel
Deactivating/activating ESP ®
on AMG vehi-
cles ( Y page 66).
For further information about ESP ®
, see
(Y page 65).
X Start the engine.
X Press the =
or ; button on the steer-
ing wheel to select the Assist. menu.
X Press the 9 or : button to select
ESP.
X Press the a button.
X To activate/deactivate: press the a
button again.
ESP ®
is deactivated if the å warning
lamp in the instrument cluster lights up
continuously when the engine is running.
If the ÷
warning lamp and the å warn-
ing lamp are lit continuously, ESP ®
is not
available due to a malfunction.
Observe the information on warning lamps
(Y page 260).
Observe the information on display messages
(Y page 230).
Activating/deactivating the distance
warning function X
Press the =
or ; button on the steer-
ing wheel to select the Assist. menu.
X Press the 9 or : button to select
Distance warning.
X Press the a button.
The current selection is displayed.
X To activate/deactivate: press the a
button again.
When the distance warning function is
deactivated, the æ symbol appears in
the multifunction display in the assistance
graphics display. 218
Menus and submenus
On-board computer and displays

X
Press the 9 or : button to select
Radar sensor (See Owner's Man.).
You will see the selected setting: Activa‐
ted or Deactivated.
X Press the a button to save the setting.
i In some countries you must deactivate
the radar sensor system. For further infor-
mation, see ( Y page 350).
If the radar sensor system is switched off,
Blind Spot Assist is deactivated
(Y page 197).
Heating Changing the departure time
X
Press the = or ; button on the steer-
ing wheel to select the Settings menu.
X Press the : or 9 button to select
theHeating submenu.
X Press a to confirm.
You will see the selected setting.
X Press a to confirm.
X Press the : or 9
button to select A,
B or Change C.
X Press a to confirm.
You can now change the departure time.
X Press the =
or ; button to select the
display to be changed: hours, minutes.
X Press the : or 9 button to set the
selected display.
X Press the a button to store the entry.
The yellow indicator lamp on the auxiliary
heating button lights up.
Selecting the departure time or deactivat-
ing a selected departure time
X Press the =
or ; button on the steer-
ing wheel to select the Settings menu.
X Press the :
or 9 button to select the
Heating submenu.
X Press a to confirm.
You will see the selected setting.
X Press a to confirm. X
Press : or 9 to select one of the
three departure times or Timer off (no
timer active).
X Press a to confirm.
If a departure time is selected, the yellow
indicator lamp lights up on the auxiliary
heating button.
Changing the departure time
Only vehicles with auxiliary heating
(Y page 134) have this function.
In the Heating submenu, you can select a
stored

departure time or change a departure
time.
The auxiliary heating timer function calcu-
lates the switch-on time according to the out-
side temperature so that the vehicle is pre-
heated by the departure time. When the
departure time is reached, the auxiliary heat-
ing continues to heat for a further five
minutes and then switches off. The auxiliary
heating adopts the THERMATIC or
THERMOTRONIC temperature setting.
You can switch off the auxiliary heating by
using the remote control or the auxiliary heat-
ing button on the centre console. G
DANGER
If the exhaust pipe is blocked or sufficient
ventilation is not possible, toxic exhaust
fumes can enter the vehicle, especially car-
bon monoxide. This is the case, e.g. in
enclosed spaces, or if the vehicle is stuck in
snow. There is a risk of fatal injuries.
You should switch off the auxiliary heating in
enclosed

spaces which do not have an extrac-
tion system, e.g. a garage. If the vehicle is
stuck in snow and you must leave the auxiliary
heating running, keep the exhaust pipe and
the area around the vehicle clear of snow. To
guarantee a sufficient supply of fresh air, open
a window on the side of the vehicle away from
the wind. G
WARNING
When the auxiliary heating is switched on,
parts of the vehicle can become very hot. 224
Menus and submenus
On-board computer and displays

Safety systems
Display messages Possible causes/consequences and
M Solutions!÷
currently unavail‐
able See Owner's
Manual ABS (Anti-lock Braking System), ESP
®
(Electronic Stability Pro-
gram), BAS (Brake Assist), PRE-SAFE ®
, the HOLD function, hill
start assist and ESP ®
trailer stabilisation are temporarily unavail-
able.
The adaptive brake lights and COLLISION PREVENTION ASSIST
may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster.
ATTENTION ASSIST is deactivated.
Possible causes:
R self-diagnosis is not yet complete.
R the on-board voltage may be insufficient
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 Carefully drive on a suitable stretch of road, making slight steer-
ing movements, at a speed above

20 km/h.
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop. !÷
inoperative See
Owner's Manual ABS, ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist
and
ESP®
trailer stabilisation are unavailable due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST
may also have failed.
In addition, the J, ÷, å and ! warning lamps light
up in the instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING230
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
M SolutionsThe 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 Drive on carefully.
X Visit a qualified specialist workshop immediately. ÷
currently unavail‐
able See Owner's
Manual 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.
In addition, the ÷ and å warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
The self-diagnosis function, for example, may not be 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.
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop. Display messages
231
On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions÷
inoperative See
Owner's Manual ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist and
ESP ®
trailer stabilisation are not available due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST
may also have failed.
In addition, the ÷ and å warning lamps light up in the
instrument cluster.
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 Drive on carefully.
X Visit a qualified specialist workshop. T!
÷
inoperative See
Owner's Manual EBD (electronic brake force distribution), ABS, ESP
®
, BAS, PRE-
SAFE ®
,

the HOLD function, hill start assist and ESP ®
trailer stabi-
lisation are unavailable due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST
may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster and a warning tone sounds.
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 Drive on carefully.
X Visit a qualified specialist workshop immediately.232
Display messages
On-board computer and displays