2012 MERCEDES-BENZ A-CLASS HATCHBACK warning light

Problem
Possible causes/consequences and
M
MSolutions Vehicles with a petrol
engine:
The engine is not run-
ning smoothly and is
misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
X Have the cause rectified immediately at a qualified specialist
workshop. The coolant tempera-
ture display is showing
more than 120 †. The
coolant warning lamp
may also be on and a
warning tone may
sound. The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X Stop as soon as possible and allow the engine and the coolant to
cool down.
X Check the coolant level (Y page 288). Observe the warning
notes as you do so and top up the coolant if necessary. If the coolant level is correct, the engine radiator fan may be faulty.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. Manual transmission
Gear lever
! Only engage gear when the clutch pedal is
depressed.
! When shifting to
5thand 6thgear, you
must press the shift lever to the right. Oth- erwise, you could shift unintentionally into
3rd or4th gear and damage the engine or
transmission.
If you shift down at too high a speed (trans-
mission braking), this can cause the engine
to overrev, leading to engine damage.
Do not use the clutch bite point to keep the vehicle stationary on uphill gradients.
There is otherwise a risk of damaging the
clutch.
! On long and steep downhill gradients,
especially if the vehicle is laden or towing a trailer, you must shift into gear
1, 2or3in
good time. This uses the engine's braking
effect. This relieves the load on the brake
system and prevents the brakes from over-
heating and wearing too quickly. Gear lever
k
Reverse gear
1 to6
Forward gears 150
Manual transmissionDriving and parking

cle from rolling away by applying the parking
brake.
Vehicles with manual transmission X
Shift to either first gear or reverse gear R.
X Turn the key to position 0in the ignition
lock and remove it.
The immobiliser is activated.
X Apply the electric parking brake.
Vehicles with automatic transmission All vehicles (except AMG vehicles)
X Apply the electric parking brake.
X Shift the transmission to position P.Selector lever in AMG vehicles
AMG vehicles:
X Apply the electric parking brake.
X Press Pbutton :.
X Turn the key to position 0in the ignition
lock and remove it.
The immobiliser is activated.
i If you switch the engine off with the trans-
mission in position Ror D, the automatic
transmission shifts to Nautomatically.
If you then open one of the front doors or
remove the key from the ignition, the auto-
matic transmission shifts to P.
If you shift the automatic transmission to N
before switching off the engine, the auto-
matic transmission remains in Neven if a
door is opened. Electric parking brake
General notes G
WARNING
If you leave children unattended in the vehi-
cle, they could set the vehicle in motion by, for example:
R releasing the parking brake
R shifting an automatic transmission out of
parking position P
R shifting a manual transmission into neutral
R starting the engine
They could also operate vehicle equipment.
There is a risk of an accident and injury.
When leaving the vehicle, always take the key with you and lock the vehicle. Never leave
children unattended in the vehicle. i
The electric parking brake carries out a
function check at regular intervals when
the engine is switched off. Noises that
occur are normal.
Engaging/releasing manually Engaging
X Push handle :.
When the electric parking brake is applied,
the ! red indicator lamp lights up in the
instrument cluster.
i The electric parking brake can also be
applied when the key is removed. Parking
163Driving and parking Z

Releasing
X Pull handle :.
The red !indicator lamp in the instru-
ment cluster goes out.
i You can only release the electric parking
brake when the key is in position 1or 2in
the ignition lock.
Applying automatically The electric parking brake is applied auto-
matically:
R if DISTRONIC PLUS brings the vehicle to a
standstill (vehicles with automatic trans-
mission) or
R if the HOLD function is keeping the vehicle
stationary.
In addition, at least one of the following con-
ditions must be fulfilled:
R the engine is switched off
R the driver's door is open and the seat belt is
not fastened
R there is a system malfunction
R the power supply is insufficient
R the vehicle is stationary for a lengthy
period.
The red !indicator lamp in the instrument
cluster lights up.
i The electric parking brake is not automat-
ically applied if the engine is switched off by
the ECO start/stop function.
Releasing automatically i
The electric parking brake can only be
released automatically in vehicles with
automatic transmission.
The electric parking brake of your vehicle is
released automatically when all of the follow- ing conditions are fulfilled:
R the engine is running.
R the transmission is in position Dor R.
R the seat belt is fastened.
R you depress the accelerator pedal. If the transmission is in position
R, the tailgate
must be closed.
If your seat belt is not fastened, the following conditions must be fulfilled to automatically
release the electric parking brake:
R the driver's door is closed.
R you have shifted out of transmission posi-
tion Por you have previously driven faster
than 3km/h.
Emergency braking The vehicle can also be braked during an
emergency using the electric parking brake.
X While driving, push handle :of the electric
parking brake (Y page 163).
i The vehicle is braked for as long as han-
dle :of the electric parking brake
pressed. The longer the electric parking
brake handle :is depressed, the greater
the braking force.
During braking:
R a warning tone sounds
R the Release parking brake Release parking brake message
appears
R the red !indicator lamp in the instru-
ment cluster flashes
When the vehicle has been braked to a stand- still, the electric parking brake is engaged. Parking up the vehicle
If you leave the vehicle parked up for longer
than four weeks, the battery may be damaged by exhaustive discharging.
If you leave the vehicle parked up for longer
than six weeks, the vehicle may suffer dam-
age as a result of lack of use.
X Visit a qualified specialist workshop and
seek advice.
i You can obtain information about trickle
chargers from a qualified specialist work-
shop. 164
ParkingDriving an
d parking

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

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

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