engine MERCEDES-BENZ A CLASS 2012 Service Manual

erwise mist up as no fresh air is drawn into
the vehicle in air-recirculation mode.
R Use the ZONE function to adopt the tem-
perature settings on the driver's side for
the front-passenger side as well. The indi-
cator lamp in the á button goes out.
R Use the residual heat function if you want
to heat or ventilate the vehicle interior
when
the ignition is switched off. The resid-
ual heat function can only be activated or
deactivated with the ignition switched off.
ECO start/stop function During automatic engine switch-off, the cli-
mate

control only operates at a reduced capa-
city. If you require the full climate control out-
put, you can switch off the ECO start/stop
function by pressing the ECO button
(Y page 147). Operating the climate control system
Switching climate control on/off
Points to observe before use When the climate control is switched off, the
air supply and air circulation are also
switched off. The windows could then mist
up.

Therefore, switch off climate control only
briefly.
THERMATIC automatic climate control X
Turn the key to position 2 in the ignition
lock (Y page 143).
X To switch on: turn
control A clockwise to
the desired position (except position 0)
(Y page 123).
X To switch off: turn control A anti-clock-
wise to position 0(Y page 123). THERMOTRONIC automatic climate
control X
Turn the key to position 2 in the ignition
lock (Y page 143).
X To activate: press the à button.
The
indicator lamp in the à button lights
up. Airflow and air distribution are set to
automatic mode.
or
X Press the ^ button.
The

indicator lamp in the ^ button goes
out. The previous settings are reactivated.
X To deactivate: press the ^ button.
The
indicator lamp in the ^ button lights
up.
i THERMOTRONIC automatic climate con-
trol: switch on climate control primarily
using the à button. Activating/deactivating the cooling
with air dehumidification function
Points to observe before use If you deactivate the "Cooling with air dehu-
midification

function", the air inside the vehi-
cle will not be cooled in warmer weather. The
air inside the vehicle will not be dehumidified
either. The windows can mist up more
quickly. Therefore, only switch off the "Cool-
ing with air dehumidification function" briefly.
The "Cooling with air dehumidification" func-
tion is only available when the engine is run-
ning. The air inside the vehicle is cooled and
dehumidified according to the temperature
selected.
Condensation may drip from the underside of
the vehicle when cooling mode is active. This
is normal and not a sign that there is a mal-
function. 126
Operating the climate control system
Climate control

immediately to open/close the side window
in the door. The side window stops. To con-
tinue closing the side window, pull on the
W switch.
X Convenience closing feature: press and
hold the e button until the side win-
dows
and the panorama sliding sunroof are
closed.
The indicator lamp in the e button lights
up. Air-recirculation mode is activated.
If parts of the body are in the closing area
during convenience closing, proceed as fol-
lows:
X To open/close the side window, press the
W button.
The side window stops.
X To then open the side window, press the
W button again.
X To open/close the panorama sliding sun-
roof press the 3 button.
The panorama sliding sunroof stops.
X To then open the panorama sliding sunroof
press the 3 button again.
X Press the d
button again for longer than
2 seconds.
The side windows move in the opposite
direction.
i Notes on the automatic reversing func-
tion for:
R the side window

(Y page 84)
R the panorama sliding sunroof
(Y page 87)
X Convenience opening feature:
press and
hold the e button until the side win-
dows and the panorama sliding sunroof
have opened. The side windows and the
panorama sliding sunroof move back to
their original position.
The indicator lamp in the e button goes
out. Air-recirculation mode is deactivated.
i If you open the side windows or the pan-
orama sliding sunroof manually after clos-
ing with the convenience closing feature, they will remain in this position when
opened

using the convenience opening fea-
ture. Activating/deactivating the residual
heat function
The residual heat function is only available
with

THERMOTRONIC automatic climate con-
trol.
It is possible to make use of the residual heat
of the engine to continue heating the vehicle
for approximately 30 minutes after the engine
has been switched off. The heating time
depends on the temperature that has been
set for the vehicle interior.
i The blower will run at a low speed regard-
less of the airflow setting.
i If you activate the residual heat function
at high temperatures, only the ventilation
will be activated. The blower runs at
medium speed.
X Turn the key to position 0 in the ignition
lock or remove it ( Y page 143).
X To activate: press the Ì button.
The
indicator lamp in the Ì button lights
up.
X To deactivate: press the Ì button.
The
indicator lamp in the Ì button goes
out.
i Residual heat is deactivated automati-
cally:
R after approximately

30 minutes
R when the ignition is switched on
R if the battery voltage drops
R when the auxiliary heating is switched on Operating the climate control system
133
Climate control Z

Auxiliary heating
Important safety notes 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.
Flammable material such as leaves, grass or
twigs

may ignite if they come into contact with
hot parts of the exhaust system for extended
periods. There is a risk of fire.
When the auxiliary heating is switched on,
make sure that no flammable material can
come into contact with hot vehicle compo-
nents.
! Operating the auxiliary heating/ventila-
tion draws on the vehicle battery. After you
have heated or ventilated the vehicle a
maximum of two times, drive for a longer
distance.
i Switch the auxiliary heating on regularly
once a month for about ten minutes.
The auxiliary heating heats the air in the vehi-
cle interior to the set temperature. This
occurs without using the heat of the running
engine. The auxiliary heating is operated
directly using the vehicle's fuel. For this rea-
son, the fuel tank must be at least ¼ full to
ensure that the auxiliary heating functions. The auxiliary heating/ventilation automati-
cally adjusts to changes in temperature and
weather

conditions. For this reason, the aux-
iliary heating could switch from ventilation
mode to heating mode or from heating mode
to ventilation mode.
The auxiliary heating switches off when the
engine is switched off. The auxiliary ventila-
tion switches off when you turn the key to key
position 2(Y page 143).
The auxiliary heating switches off automati-
cally after 30 minutes.
You cannot use the auxiliary ventilation to
cool the vehicle interior to a temperature
lower than the outside temperature.
Before switching on X
Turn the key to position 2 in the ignition
lock (Y page 143).
X Set the desired temperature.
Auxiliary heating or ventilation can also be
switched on if the manually set climate con-
trol is activated. Optimum comfort can be
attained

when the system is set to automatic
mode. Set the temperature to 22 †.
The auxiliary heating/ventilation can be acti-
vated or deactivated using the remote control
or the button on the centre console.
The on-board computer can be used to spec-
ify up to three departure times, one of which
may be preselected ( Y page 224).134
Operating the climate control systemClimate control

Problems with the auxiliary heating/ventilation
Display messages Possible causes/consequences and
M Solutions$
FAIL The signal transmission between the transmitter and the vehicle
is faulty.
X
Change your position in relation to the vehicle, moving closer if
necessary.
X Make another attempt to switch the auxiliary heating on or off
using the remote control. ©
FAIL There is too little fuel in the fuel tank.
X
Refuel at the nearest filling station.
X Make another attempt to switch on the auxiliary heating using
the remote control. The auxiliary heating is faulty.
X
Have the auxiliary heating checked at a qualified specialist
workshop. FAIL The auxiliary heating cannot be switched on or has switched itself
off.
The
auxiliary heating was started more than twice when the engine
was switched off.
X Switch on the engine and let it run for more than ten seconds.
X Make another attempt to switch on the auxiliary heating using
the remote control. The auxiliary heating cannot be switched on or has switched itself
off.
The starter battery is not sufficiently charged.
X
Charge the starter battery.
X Make another attempt to switch on the auxiliary heating using
the remote control.138
Operating the climate control system
Climate control

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). Running-in notes
Important safety notes
New brake pads/linings and discs that have
been

replaced only achieve optimum braking
effect after several hundred kilometres of
driving. Compensate for the reduced braking
effect by applying greater force to the brake
pedal. The first 1500 km
If you treat the engine with sufficient care
from

the very start, you will be rewarded with
excellent performance for the remainder of
the engine's life.
R Drive at varying vehicle speeds and engine
speeds for the first 1500 km.
R Avoid overstraining the vehicle during this
period, e.g. driving at full throttle.
R Change gear in good time, before the rev
counter needle is Ô of the way to the red
area of the rev counter.
R Do not shift down a gear manually in order
to brake.
Vehicles with automatic transmission:
R Try to avoid depressing the accelerator
pedal beyond the point of resistance (kick-
down).
After 1,500 km, you may gradually bring the
vehicle up to full road and engine speeds. Additional running-in notes for AMG vehicles:
R
Do

not drive at speeds above 140 km/h for
the first 1,500 km.
R Only allow the engine to reach a maximum
engine speed of 4,500 rpm briefly.
i You should also observe these notes on
running-in if the engine or parts of the drive
train on your vehicle have been replaced. Driving
Important safety notes
G
WARNING
Objects in the driver's footwell may restrict
the clearance around the pedals or block a
depressed pedal. This jeopardises the oper-
ating and road safety of the vehicle. There is
a risk of an accident.
Stow

all objects securely in the vehicle so that
they do not get into the driver's footwell.
Always fit the floormats securely and as pre-
scribed in order to ensure that there is always
sufficient room for the pedals. Do not use
loose floormats and do not place several floor-
mats on top of one another. G
WARNING
Unsuitable footwear can hinder correct usage
of the pedals, e.g.:
R shoes with thick soles
R shoes with high heels
R slippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals. G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with

limitations, or not at all. This could affect,
for example, the power steering and the brake
boosting effect. You will require considerably 142
Driving
Driving and parking

more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving.
G
WARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only set the automatic transmission to the
respective drive positions when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. Otherwise, you could damage the
drive train.
! AMG vehicles: avoid full-load operation
and engine speeds greater than 5000 rpm
when the engine is cold. This helps to pro-
tect the engine and avoids uncomfortable
driving. Key positions
g
To remove the key
1 Power supply for some consumers, such
as the windscreen wipers 2
Ignition (power supply for all consumers)
and drive position
3 To start the engine
Vehicles with manual transmission: the
steering is locked when the key is taken out
of the ignition lock.
i If the key does not belong to the vehicle,
it can still be turned in the ignition lock.
However, the ignition will not be switched
on. The engine cannot be started. Starting the engine
Important safety notes G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these

exhaust gases leads to poisoning. There
is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation. G
WARNING
Flammable materials introduced through
environmental influence or by animals can
ignite

if in contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
! Do not depress the accelerator pedal
when starting the engine.
i Vehicles with a petrol engine: the
engine runs at a higher engine speed during
the cold start procedure so that the cata-
lytic converter can reach operating tem-
perature more quickly. The sound of the
engine may change as a result. Driving
143
Driving and parking Z

Manual transmission
X
Depress the brake pedal and keep it
depressed.
X Depress the clutch pedal fully.
X Shift to neutral N.
i You can only start the engine when the
clutch pedal is fully depressed.
Automatic transmission X
Shift the transmission to position P.
Transmission position display P is shown in
the multifunction display.
i When the transmission is in position N,
you

can also start the engine with the brake
pedal depressed.
Starting procedure X
To start a petrol engine: turn the key to
position 3 in the ignition lock
(Y page 143) and release it as soon as the
engine is running.
X To start a diesel engine: turn the key to
position 2 in the ignition lock
(Y page 143).
The % preglow indicator lamp in the
instrument cluster lights up.
X When the % preglow indicator lamp
goes out, turn the key to position
3(Y

page 143) and release it as soon as the
engine is running.
i You
can start the engine without preglow
if the engine is warm. Pulling away
Manual transmission !
Change
gear in good time and avoid spin-
ning the wheels. Otherwise, you could dam-
age the vehicle. X
Depress the brake pedal and keep it
depressed.
X Depress the clutch pedal fully.
X Shift to either first gear or reverse gear R.
X Release the electric parking brake
(Y page 163).
X Release the brake pedal.
X Slowly release the clutch pedal and gently
depress the accelerator pedal.
i Follow the shift recommendations in the
multifunction display for an economical
driving style ( Y page 151).
i The

vehicle locks centrally once you have
pulled away. The locking knobs in the doors
drop down.
You can open the doors from the inside at
any time.
You can also deactivate the automatic lock-
ing feature ( Y page 223).
Automatic transmission 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.
X Depress the brake pedal and keep it
depressed.
X Shift the transmission to position D or R.
X Release the brake pedal.
X Carefully depress the accelerator pedal.
The electric parking brake (Y page 163) is
automatically released.
The red ! indicator lamp in the instru-
ment cluster goes out. 144
Driving
Driving and parking

i
The vehicle locks centrally once you have
pulled away. The locking knobs in the doors
drop down.
You can open the doors from the inside at
any time.
You can also deactivate the automatic lock-
ing feature ( Y page 223).
i Upshifts take place at higher engine
speeds after a cold start. This helps the
catalytic converter to reach its operating
temperature more quickly.
Pulling away with a trailer To ensure that you do not roll backwards
when

pulling away on an uphill slope, engage
the electric parking brake.
X Press and hold handle :.
The electric parking brake continues to
brake and prevent the vehicle from rolling
backwards.
The red ! indicator lamp in the instru-
ment cluster remains lit.
X Depress the accelerator pedal.
X As soon as the vehicle/trailer combination
is held by the driving force of the engine,
release lever :.
The electric parking brake is released.
The red ! indicator lamp in the instru-
ment cluster goes out.
i For further information on the electric
parking brake, see ( Y page 163). Hill start assist G
WARNING
After a short time, hill start assist will no lon-
ger brake your vehicle and it could roll away.
There is a risk of an accident and injury.
Therefore, quickly move your foot from the
brake pedal to the accelerator pedal. Never
leave the vehicle when it is held by hill start
assist.
Hill start assist helps you when pulling away
forwards or in reverse on an uphill gradient.
It holds the vehicle for a short time after you
have

removed your foot from the brake pedal.
This gives you enough time to move your foot
from the brake pedal to the accelerator pedal
and depress it before the vehicle begins to
roll.
X Remove your foot from the brake pedal.
The

vehicle is then held for about a second.
X Pull away.
Hill start assist will not function if:
R you are pulling away on a level road or a
downhill gradient.
R on vehicles with automatic transmission,
the transmission is in position N.
R the electric parking brake is engaged.
R ESP ®
is malfunctioning.
Further information on holding the vehicle
stationary on uphill gradients

(Y page 154). ECO start/stop function
Introduction The ECO start/stop function switches the
engine

off automatically if the vehicle is stop-
ped under certain conditions.
When pulling away again, the engine starts
automatically. The ECO start/stop function
thereby helps you to reduce the fuel con-
sumption and emissions of your vehicle. Driving
145
Driving and parking Z

Important safety notes
G
WARNING
If the engine is switched off automatically and
you exit the vehicle, the engine is restarted
automatically.
The vehicle may begin moving.
There is a risk of accident and injury.
If you wish to exit the vehicle, always turn off
the ignition and secure the vehicle against
rolling away.
General notes :
ECO start/stop display
If the ¤ symbol is shown in green in the
multifunction display, the ECO start/stop
function switches the engine off automati-
cally if the vehicle stops moving.
The

stop/start function is automatically acti-
vated each time you start the engine with the
ignition key.
If the ECO start/stop function has been man-
ually deactivated ( Y page 147) or a malfunc-
tion has caused the system to be deactivated,
the ¤ symbol is not displayed.
AMG vehicles: the ECO start/stop function
is only available in drive program C.
Automatic engine switch-off General notes
The ECO start/stop function is operational
and the
¤ symbol is displayed in green in
the multifunction display, if:
R the indicator lamp in the ECO button is lit
green
R the

outside temperature is within the range
that is suitable for the system R
the engine is at normal operating temper-
ature
R the

set temperature for the vehicle interior
has been reached
R the battery is sufficiently charged
R the system detects that the windscreen is
not misted up when the air-conditioning
system is switched on
R the bonnet is closed
R the driver's door is closed and the driver's
seat belt is fastened
If not all conditions for automatic engine
switch-off are fulfilled, the ¤ symbol is
shown in yellow.
i All of the vehicle's systems remain active
when the engine is switched off automati-
cally.
i The engine can be switched off automat-
ically a maximum of four times (initial stop,
then three subsequent stops) in succes-
sion. The ¤ symbol is shown in yellow
in the multifunction display after the engine
has been started automatically for the
fourth time. When the ¤ symbol is
shown in green in the multifunction display,
automatic engine switch-off is again possi-
ble.
Vehicles with manual transmission
The ECO start/stop function switches off the
engine automatically at low speeds. X
Brake the vehicle.
X Engage neutral N(Y page 151) (follow
gearshift instruction : to engage neutral
N, if necessary).
X Release the clutch pedal.
The engine is switched off automatically.146
Driving
Driving and parking

Vehicles with automatic transmission
If the vehicle is braked to a standstill in
D or
N, the ECO start/stop function switches off
the engine automatically.
i The
HOLD function can be activated if the
engine has been switched off automati-
cally. It is then not necessary to continue
applying the brakes during the automatic
stop phase. When you depress the accel-
erator pedal, the engine starts automati-
cally and the braking effect of the HOLD
function is deactivated.
Automatic engine start General notes
The engine is started automatically if:
R
you

switch off the ECO start/stop function
by pressing the ECO button
R you engage reverse gear R
R the vehicle starts to roll
R the brake system requires this
R the temperature in the vehicle interior devi-
ates from the set range
R the system detects moisture on the wind-
screen when the air-conditioning system is
switched on
R the battery's charge status is too low
R the driver's seat belt is released or the driv-
er's door is opened
Vehicles with manual transmission
! Only engage gear when the clutch pedal
is depressed.
The engine is started automatically if you:
R depress the clutch pedal fully
R depress the accelerator pedal Vehicles with automatic transmission
The engine is started automatically if you:
R
release the brake pedal when HOLD is not
activated and the transmission is in posi-
tion D or N
R depress the accelerator pedal
R move the transmission out of position P
i Shifting the transmission to position P
does not start the engine.
i If you shift the transmission from R to D,
the ECO start/stop function is available
again once the ¤ symbol reappears in
green in the multifunction display.
Deactivating/activating the ECO start/
stop function ECO button
X
To switch off: press button :.
Indicator lamp ; and the ¤ symbol in
the multifunction display go out.
X To switch on: press button :.
Indicator lamp ; lights up.
If all conditions for automatic engine
switch-off ( Y page 146) are met, the ¤
symbol is shown in green in the multifunc-
tion display.
If not all conditions for automatic engine
switch-off ( Y page 146) are met, the ¤
symbol

is shown in yellow in the multifunc-
tion display. If this is the case, the ECO
start/stop function is not available. Driving
147
Driving and parking Z