warning MERCEDES-BENZ A-CLASS HATCHBACK 2012 Owners Manual

dynamic changes in the bars at the start of
a journey. During a prolonged driving time,these changes are smaller. For more
dynamic changes, perform a manual reset.
For further information on the ECO display,
see (Y page 212). Braking
Important safety notes G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
This increases the risk of skidding and having
an accident.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients Change into a lower gear in good time on long
and steep downhill gradients. Take particular note of this when driving a laden vehicle and
when towing a trailer. For vehicles with auto-
matic transmission, you need to have selec-
ted manual drive program M(Ypage 156).
i This also applies if you have activated
cruise control, SPEEDTRONIC or DIS-
TRONIC PLUS.
This will use the braking effect of the engine,
so less braking will be required to prevent the
vehicle from gaining speed. This relieves the
load on the brake system and prevents the
brakes from overheating and wearing too
quickly.
i Briefly depressing the accelerator pedal
on downhill gradients while the manual
drive program Mis temporarily activated
(vehicles with automatic transmission): the
automatic transmission may switch back to the last active automatic drive program Eor
S. The automatic transmission may shift to a higher gear. This can reduce the engine's
braking effect.
Heavy and light loads G
WARNING
The braking system can overheat if you leave your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There is
a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal and the accelerator pedal while driving.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If heavy demands are made on the brakes, do not park the vehicle immediately. Drive on for
a short while. This allows the airflow to cool
the brakes more quickly.
If the brakes have been used only moderately,
you should occasionally test their effective-
ness. To do this, brake more firmly from a
higher speed, paying attention to traffic con-
ditions. This improves the grip of the brakes.
Wet road surfaces If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first time. This may also occur after a car wash orafter driving through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehi-
cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up
the brake discs, thereby drying them more
quickly and protecting them against corro-
sion. 166
Driving tipsDriving and parking

Limited braking performance on salt-
treated roads If you drive on salted roads, a layer of salt
residue may form on the brake discs and
brake pads. This can result in a significantly
longer braking distance.
R Brake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so.
R Carefully depress the brake pedal and the
beginning and end of a journey.
R Maintain a greater distance to the vehicle
ahead.
New brake pads/linings New and replaced brake pads and discs only
reach their optimum braking effect after sev-
eral hundred kilometres of driving. Compen-
sate for this by applying greater force to the
brake pedal.
For safety reasons, Mercedes-Benz recom-
mends that you only have brake pads/linings fitted to your vehicle which have been
approved for Mercedes-Benz vehicles or
which correspond to an equivalent quality
standard. Brake pads/linings which have not been approved for Mercedes-Benz vehicles or
which are not of an equivalent quality could
affect your vehicle's operating safety. Driving on wet roads
Aquaplaning If water has accumulated to a certain depth
on the road surface, there is a danger of aqua- planing occurring, even if:
R you are driving at low speeds
R the tyres have adequate tread depth
For this reason, do not drive in tyre ruts and
brake carefully. Driving on flooded roads !
Bear in mind that vehicles travelling in
front or in the opposite direction create
waves. This may cause the maximum per-
missible water depth to be exceeded.
These notes must be observed under all
circumstances. You could otherwise dam-
age the engine, the electronics or the trans- mission.
If you have to drive on stretches of road on
which water has collected, please bear in
mind that:
R the maximum permissible fording depth in
still water is 25 cm
R you should drive no faster than walking
pace Winter driving
General notes G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
This increases the risk of skidding and having
an accident.
Do not shift down for additional engine brak-
ing on a slippery road surface. G
DANGER
If the exhaust pipe is blocked or adequate
ventilation is not possible, poisonous gases
such as carbon monoxide (CO) may enter the vehicle. This is the case, e.g. if the vehicle
becomes trapped in snow. There is a risk of
fatal injury.
If you leave the engine or the auxiliary heating
running, make sure the exhaust pipe and area
around the vehicle are clear of snow. To
ensure an adequate supply of fresh air, open a window on the side of the vehicle that is not
facing into the wind. Driving tips
167Driving and parking Z

Have your vehicle winterproofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Winter operation"
section (Y page 320).
Driving with summer tyres Observe the notes in the "Winter operation"
section (Y page 320).
Slippery road surfaces G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
This increases the risk of skidding and having
an accident.
Do not shift down for additional engine brak-
ing on a slippery road surface.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
X Vehicles with manual transmission:
shift to neutral.
X Vehicles with automatic transmission:
shift the transmission to position N.
X Try to bring the vehicle under control by
using corrective steering.
You should drive particularly carefully on slip-
pery road surfaces. Avoid sudden accelera-
tion, steering and braking manoeuvres.
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Changes in the outside temperature are dis-
played after a short delay.
Indicated temperatures just above the freez-
ing point do not guarantee that the road sur-
face is free of ice. The road may still be icy,
especially in wooded areas or on bridges. You should pay special attention to road condi-
tions when temperatures are around freezing
point.
i For more information on driving with
snow chains, see (Y page 321). Driving systems
Cruise control
Important safety notes If you fail to adapt your driving style, cruise
control can neither reduce the risk of an acci-
dent nor override the laws of physics. Cruise
control cannot take into account road,
weather or traffic conditions. Cruise control is only an aid. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed,
for braking in good time, and for staying in the lane.
Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed
(e.g. in heavy traffic or on winding roads).
R on smooth or slippery roads. Braking or
accelerating can cause the drive wheels to
lose traction and the vehicle could then
skid.
R when there is poor visibility, e.g. due to fog,
heavy rain or snow.
If there is a change of drivers, advise the new driver of the speed stored.
General notes Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. You must
select a lower gear in good time on long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer. For vehi-
cles with automatic transmission, you need to have selected manual drive program
M(Y page 156). By doing so, you will make
use of the braking effect of the engine. This
relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly.
Use cruise control only if road and traffic con-
ditions make it appropriate to maintain a
steady speed for a prolonged period. You can store any road speed above 30 km/h. 168
Driving systemsDriving and parking

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 Nwhile driving.
If cruise control is deactivated, you will hear a warning tone. You will see the Cruise con‐
Cruise con‐
trol off trol off message in the multifunction dis-
play for approximately five seconds.
i The last speed stored is cleared when you
switch off the engine. 170
Driving systemsDriving and parking

Storing the current speed
You can use the cruise control lever to limit
the speed to any speed above 30 km/hw hile
the engine is running.
X Briefly press the cruise control lever up :
or down ?.
The current speed is stored. For five sec-
onds, the multifunction display shows the
stored speed, e.g. Limit 100 km/h Limit 100 km/h.
The segments in the speedometer light up
from the start of the scale up to the stored
speed.
Storing the current speed and calling up
the last stored speed G
WARNING
If you call up the stored speed and it is lower
than the current speed, the vehicle deceler-
ates. If you do not know the stored speed, the vehicle could decelerate unexpectedly. There
is a risk of an accident.
Pay attention to the road and traffic condi-
tions before calling up the stored speed. If you do not know the stored speed, store the
desired speed again.
X Briefly pull the cruise control lever towards
you =.
X To adjust the set speed in 1 km/h incre-
ments: briefly press the cruise control
lever up :to the pressure point for a
higher speed, or down ?for a lower speed.
or
X Keep the cruise control lever pressed to the
pressure point until the desired speed is
set. Press the cruise control lever up :for
a higher speed or down ?for a lower
speed.
X To adjust the set speed in 10 km/h
increments: briefly press the cruise con-
trol lever up :past the pressure point for a higher speed, or down
?for a lower
speed.
or
X Keep the cruise control lever pressed
beyond the pressure point until the desired
speed is set. Press the cruise control lever
up : for a higher speed or down ?for a
lower speed.
Deactivating variable SPEEDTRONIC
It is not possible to deactivate variable
SPEEDTRONIC by braking.
There are several ways to deactivate variable SPEEDTRONIC:
X Briefly press the cruise control lever for-
wards B.
or X Briefly press the cruise control lever in the
direction of arrow A.
LIM indicator lamp ;in the cruise control
lever goes out. Variable SPEEDTRONIC is
deactivated.
Cruise control or DISTRONIC PLUS is selec- ted.
Variable SPEEDTRONIC is automatically
deactivated if:
R you depress the accelerator pedal beyond
the pressure point (kickdown), but only if
your current speed does not differ by more
than 20 km/h from the stored speed. You
will hear a warning tone if this is the case.
R on vehicles with manual transmission, if
you shift to a higher gear and as a result, the
engine speed is too low.
i The last speed stored is cleared when you
switch off the engine.
Permanent SPEEDTRONIC You can use the on-board computer to limit
the speed permanently to a value between
160 km/h(e.g. for driving on winter tyres) and
the maximum speed (Y page 223).
Shortly before the stored speed is reached, it appears in the multifunction display. 172
Driving systemsDriving and parking

Permanent SPEEDTRONIC remains active,
even if variable SPEEDTRONIC is deactivated.
You cannot exceed the stored limit speed,
even if you depress the accelerator pedal
beyond the pressure point (kickdown). DISTRONIC PLUS
Important safety notes G
WARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. G
WARNING
DISTRONIC PLUS cannot always clearly iden- tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS. G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 40% of the maximum braking force. If this
braking force is insufficient, DISTRONIC PLUS
warns you visually and audibly. There is a risk
of an accident.
In such cases, apply the brakes yourself and
try to take evasive action. !
If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations. To prevent dam-
age to the vehicle, deactivate DISTRONIC
PLUS and the HOLD function in the follow- ing or other similar situations:
R when towing the vehicle
R in the car wash
If you fail to adapt your driving style, DIS-
TRONIC PLUS can neither reduce the risk of
an accident nor override the laws of physics. DISTRONIC PLUS cannot take road and
weather conditions or traffic conditions into
account. DISTRONIC PLUS is only an aid. You
are responsible for the distance to the vehicle
in front, for vehicle speed, for braking in good time, and for staying in the lane.
Do not use DISTRONIC PLUS:
R in road and traffic conditions which do not
allow you to maintain a constant speed
(e.g. in heavy traffic or on winding roads).
R on smooth or slippery roads. Braking or
accelerating can cause the drive wheels to
lose traction and the vehicle could then
skid.
R when there is poor visibility, e.g. due to fog,
heavy rain or snow.
DISTRONIC PLUS may not detect narrow
vehicles driving in front, e.g. motorcycles, or
vehicles driving on a different line.
In particular, the detection of obstacles can
be impaired by:
R dirt on the sensors or anything else cover-
ing the sensors
R snow or heavy rain
R interference by other radar sources
R the possibility of strong radar reflections,
for example, in multi-storey car parks
If DISTRONIC PLUS no longer detects a vehi-
cle in front, it may unexpectedly accelerate to the speed stored. Driving systems
173Driving and parking Z

This speed can:
R be too high for a filter lane or a slip road
R be so high in the right lane that you pass
vehicles driving on the left
R be so high in the left lane that you pass
vehicles driving on the right
If there is a change of drivers, advise the new driver of the speed stored.
General notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. DIS-
TRONIC PLUS brakes automatically so that
the set speed is not exceeded.
You must select a lower gear in good time on long and steep downhill gradients, especially if the vehicle is laden or towing a trailer. For
this, you need to have selected manual drive
program M(Ypage 166). By doing so, you will
make use of the braking effect of the engine.
This relieves the load on the brake system and prevents the brakes from overheating and
wearing too quickly.
If a slower-moving vehicle is detected in front,
DISTRONIC PLUS brakes your vehicle. It
maintains the preset distance to the vehicle in front.
If DISTRONIC PLUS detects that there is a risk of a collision, you will be warned visually and
acoustically. Without your intervention, DIS-
TRONIC PLUS cannot prevent a collision. An
intermittent warning tone will then sound and
the distance warning lamp will light up in the instrument cluster. Brake immediately to
increase the distance to the vehicle driving in
front, or take evasive action, provided it is
safe to do so.
The radar sensor system is switched off auto- matically in the vicinity of radio telescope
facilities (Y page 350).
For DISTRONIC PLUS to assist you when driv- ing, the radar sensor system must be:
R activated (Y page 223)
R operational i
In some countries you must deactivate
the radar sensor system (Y page 223).
For further information about the radar sen- sor system; see (Y page 350).
DISTRONIC PLUS is automatically deactiva-
ted if:
R you are driving slower than 25 km/h and
there is no longer a vehicle in front or
R the vehicle ahead has not been detected
If there is no vehicle in front, DISTRONIC
PLUS operates in the same way as cruise
control in the speed range between 30 km/h
and 200 km/h. If a vehicle is driving in front of
you, it operates in the speed range between
0 km/h and 200 km/h.
Do not use DISTRONIC PLUS on roads with
steep gradients.
Cruise control lever With the cruise control lever, you can operate
DISTRONIC PLUS and variable SPEED-
TRONIC.
The LIM indicator lamp on the cruise control
lever indicates which system you have selec- ted:
R LIM indicator lamp off: DISTRONIC PLUS
is selected.
R LIM indicator lamp on: variable SPEED-
TRONIC is selected. :
To store the current speed or a higher
speed
; To set the specified minimum distance
= LIM indicator lamp 174
Driving systemsDriving and parking

When DISTRONIC PLUS is activated, one or
two segments ;in the set speed range light
up.
i For design reasons, the speed displayed
in the speedometer may differ slightly from
the speed set for DISTRONIC PLUS.
If DISTRONIC PLUS detects a vehicle in front,
segments ;between speed of the vehicle in
front :and stored speed =light up. Assistance graphic in vehicles with a colour multi-
function display
: Vehicle in front, if detected
; Specified minimum distance to the vehi-
cle in front; adjustable
= Own vehicle
? DISTRONIC PLUS active (text only
appears when the cruise control lever is
actuated)
In the Assistance menu (Y page 217) of the
on-board computer, you can select the assis- tance graphic.
X Select the Distance display
Distance display function
using the on-board computer
(Y page 217).
i You will see the stored speed for approx-
imately five seconds when you activate
DISTRONIC PLUS.
Activating at the current speed/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
(Y page 174) towards you ?.
X Remove your foot from the accelerator
pedal.
DISTRONIC PLUS is activated. The first
time it is activated, the current speed is
stored. Otherwise, it sets the vehicle cruise
speed to the previously stored value.
Setting a speed Keep in mind that it may take a brief moment
until the vehicle has accelerated or braked to the set speed. :
To store the current speed or a higher
speed
; To store the current speed or a lower
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. DISTRONIC PLUS
is activated and adjusts the vehicle's speed to the new speed stored. 176
Driving systemsDriving and parking

DISTRONIC PLUS is automatically deactiva-
ted if:
R you apply the electric parking brake or if the
vehicle is automatically secured with the
electric parking brake
R you are driving slower than 10 km/h and
there is no longer a vehicle in front, or if the vehicle in front is no longer detected
R ESP ®
intervenes or you deactivate ESP ®
R the transmission is in the P,Ror Nposition
R you switch off the radar sensor system
R you pull the cruise control lever towards
you in order to pull away and the front-
passenger door or one of the rear doors is
open
R the vehicle is skidding
R you activate Active Parking Assist
If DISTRONIC PLUS is deactivated, you will
hear a warning tone. You will see the DIS‐
DIS‐
TRONIC TRONIC PLUS
PLUSoff
offmessage in the multifunc-
tion display for approximately five seconds.
In the Assistance menu (Y page 217) of the
on-board computer, you can select the assis-
tance graphic. :
Vehicle in front, if detected
; Distance indicator: current distance to
the vehicle in front
= Specified minimum distance to the vehi-
cle in front; adjustable
? Own vehicle
X Select the Distance display
Distance display function
using the on-board computer
(Y page 217). Tips for driving with DISTRONIC PLUS General notes
The following contains descriptions of certain
road and traffic conditions in which you must be particularly attentive. In such situations,
brake if necessary. DISTRONIC PLUS is then
deactivated.
Cornering, going into and coming out of a
bend The ability of DISTRONIC PLUS to detect vehi-
cles when cornering is limited. Your vehicle
may brake unexpectedly or late.
Vehicles which are not driving in the mid- dle of their lane DISTRONIC PLUS may not detect vehicles
which are not driving in the middle of their
lane. The distance to the vehicle in front will
be too short.178
Driving systemsDriving an
d 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
179Driving and parking Z