2012 MERCEDES-BENZ A CLASS check engine

Adaptive brake lamps
If you brake sharply from a speed of more
than
50 km/h or if braking is assisted by BAS
or adaptive Brake Assist, the brake lamps
flash rapidly. In this way, traffic travelling
behind you is warned in an even more notice-
able manner.
If you brake sharply from a speed of more
than 70 km/h to a standstill, the hazard warn-
ing lamps are activated automatically. If the
brakes are applied again, the brake lamps
light up continuously. The hazard warning
lamps switch off automatically if you travel
faster than 10 km/h. You can also switch off
the hazard warning lamps using the hazard
warning switch button (Y page 108).
i Adaptive brake lamps are only available in
certain countries. ESP
®
(Electronic Stability Program)
General notes i
Observe
the "Important safety notes" sec-
tion (Y page 61).
ESP ®
monitors driving stability and traction,
i.e. power transmission between the tyres
and the road surface.
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilise the
vehicle. The engine output is also modified to
keep the vehicle on the desired course within
physical limits. ESP ®
assists the driver when
pulling away on wet or slippery roads. ESP ®
can also stabilise the vehicle during braking.
ETS/4ETS (Electronic Traction System) i
Observe
the "Important safety notes" sec-
tion (Y page 61).
ETS/4ETS traction control is part of ESP ®
.
ETS brakes the drive wheels individually if
they spin. This enables you to pull away and
accelerate on slippery surfaces, for example if the road surface is slippery on one side. In
addition, more drive torque is transferred to
the wheel or wheels with traction.
ETS remains active when you deactivate
ESP
®
.
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilise
the vehicle. In addition, other driving
safety systems are switched off. This increa-
ses the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
! When testing the electric parking brake
on a braking dynamometer, switch off the
ignition. Application of the brakes by
ESP ®
may otherwise destroy the brake sys-
tem.
! Vehicles with 4MATIC: switch off the igni-
tion when the electric parking brake is
being tested using a dynamometer.
Application of the brakes by ESP ®
may oth-
erwise destroy the brake system.
! Vehicles with 4MATIC: function or per-
formance tests may only be carried out on
a 2-axle dynamometer. Before operating
the vehicle on such a dynamometer, please
consult a qualified specialist workshop.
You could otherwise damage the drive train
or the brake system.
! Do not tow vehicles with 4MATIC with the
front or rear axle raised.
Vehicles without 4MATIC: when towing your
vehicle with the front axle raised, it is impor-
tant that you observe the notes on
ESP ®
(Y page 312).
Vehicles with 4MATIC: when towing your
vehicle with both axles on the ground, it is
important that you observe the notes on
ESP ®
(Y page 312). Driving safety systems
65
Safety Z

EBD (electronic brake force distribu-
tion)
i Observe
the "Important safety notes" sec-
tion for driving safety systems
(Y page 61). G
WARNING
If EBD has malfunctioned, the rear wheels can
still lock, e.g. under full braking. This increa-
ses the risk of skidding and an accident.
You should therefore adapt your driving style
to

the different handling characteristics. Have
the brake system checked at a qualified spe-
cialist workshop.
Observe information regarding indicator and
warning lamps ( Y page 258) as well as dis-
play messages (Y page 232).
EBD monitors and controls the brake pres-
sure on the rear wheels to improve driving
stability while braking. ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and

offers increased braking comfort. In addi-
tion to the braking function, ADAPTIVE BRAKE
also has the HOLD function (Y page 180) and
hill start assist ( Y page 145). For further
information, see Driving tips (Y page 166). STEER CONTROL
STEER
CONTROL helps you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilisation.
This steering support is provided in particular
if:
R both right wheels or both left wheels are on
a wet or slippery road surface when you
brake
R the vehicle starts to skid.
If there is an ESP ®
malfunction, you will not
receive any steering support from STEER CONTROL. Power steering will, however, con-
tinue to function.
Anti-theft systems
Immobiliser
The immobiliser prevents your vehicle from
being started without the correct key.
X To activate:
remove the key from the igni-
tion lock.
X To deactivate: switch on the ignition.
When leaving the vehicle, always take the key
with
you and lock the vehicle. The engine can
be started by anyone with a valid key that is
left inside the vehicle.
i The immobiliser is always deactivated
when you start the engine. ATA (Anti-Theft Alarm system)
X
To prime: lock the vehicle with the key.
Indicator lamp : flashes. The alarm sys-
tem is primed after approximately
15 seconds.
X To deactivate:
unlock the vehicle with the
key.
or
X Insert the key into the ignition lock. Anti-theft systems
69
Safety Z

Problem Possible causes/consequences and
M SolutionsThe engine cannot be
started using the key. The on-board voltage is too low.
X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 304).
or
X Jump-start the vehicle (Y page 308).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the key. The steering lock is mechanically blocked.
X
Remove the key and reinsert it into the ignition lock. While doing
this, turn the steering wheel in both directions. Doors
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shift the automatic transmission out of
parking position P.
R shift the manual transmission into neutral.
R start the engine.
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 or animals unattended in the vehicle.
Always keep the key out of reach of children. G
WARNING
If persons (particularly children) are exposed
to heat or cold for a prolonged period, there
is

a risk of serious or even fatal injuries. Never
leave persons (particularly children) unatten-
ded in the vehicle.
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside.

People in the vehicle can no longer get
out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld-
erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked with the key,
then the double lock function is activated as
standard. You can deactivate the double lock
function by deactivating the interior motion
sensor (Y page 70). The doors can then be
opened from the inside after the vehicle has
been locked from the outside. The anti-theft Doors
79
Opening and closing Z

Adjusting the seat backrest side bol-
sters
X
To set the side bolsters of the seat
backrest narrower: press button A.
X To set the side bolsters of the seat
backrest wider: press button B. Steering wheel
Important safety notes
G
WARNING
You could lose control of the vehicle while
driving if you:
R adjust the driver's seat, steering wheel or
mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust
the driver's seat, head restraint, steer-
ing wheel and mirrors and fasten your seat
belt before starting the engine. G
WARNING
Children could become trapped by the steer-
ing wheel if they adjust it. There is a risk of
injury.
When

leaving the vehicle, always take the key
with you and lock the vehicle. Never leave
children unattended in the vehicle. Adjusting the steering wheel
G
WARNING
The steering wheel may move unexpectedly if
you adjust it while driving. This could cause
you to lose control of the vehicle. There is a
risk of an accident.
Make sure that the steering wheel is locked
before driving off. Never unlock the steering
wheel when the vehicle is in motion. :
Release lever
; To adjust the steering wheel height
= To adjust the steering wheel position
(fore-and-aft adjustment)
X Push release lever : down completely.
The steering column is unlocked.
X Adjust the steering wheel to the desired
position.
X Push release lever : up completely.
The steering column is locked.
X Check if the steering column is locked.
When doing so, try to push the steering
wheel up or down or try to move it in the
fore-and-aft direction. Mirrors
Rear-view mirror
X
Anti-dazzle mode: pivot anti-dazzle
switch : forwards or back. 98
Mirrors
Seats, steering wheel and mirrors

The interior lighting is activated for a short
time when the key is removed from the igni-
tion lock. You can activate this delayed
switch-off using the on-board computer
(Y page 223).
Manual interior lighting control
X
To switch the front interior lighting on:
set the switch to the c position.
X To switch off the interior lighting: set the
switch to the | position or (if the door
is closed) to the centre position.
X To switch the rear interior lighting on/
off: press the u button.
X To switch the reading lamps on/off:
press the p button. Crash-responsive emergency lighting
The
interior lighting is activated automatically
if the vehicle is involved in an accident.
X To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or
X Lock and then unlock the vehicle using the
key. Replacing bulbs
Important safety notes
Xenon bulbs G
DANGER
Xenon bulbs are under high voltage. You can
get
an electric shock if you remove the cover
of the xenon bulb and touch the electrical
contacts. There is a risk of fatal injury.
Never touch the parts or the electrical con-
tacts of the xenon bulb. Always have work on
the xenon bulbs carried out at a qualified spe-
cialist workshop. If your vehicle is equipped with xenon bulbs,
you can recognise this by the following: the
cone of light from the xenon bulbs moves
from the top to the bottom and back again
when you start the engine. For this to be
observed, the lights must be switched on
before starting the engine.
Bulbs and lamps are an important aspect of
vehicle

safety. You must therefore make sure
that these function correctly at all times.
Have the headlamp setting checked regularly.
Other bulbs G
WARNING
Bulbs, lamps and plug connectors can
become very hot during use. When replacing
a

bulb, you could burn yourself on these com-
ponents. There is a risk of injury.
Allow these components to cool down before
replacing the bulb.
There are bulbs other than the xenon bulbs
that you cannot replace. Replace only the
bulbs listed (Y page 113). Have the bulbs that
you cannot replace yourself replaced at a
qualified specialist workshop.
If you require assistance replacing bulbs, con-
sult a qualified specialist workshop.
Do not touch the glass tube of new bulbs with
your bare hands. Even minor contamination
can burn into the glass surface and reduce
the service life of the bulbs. Always use a lint-
free cloth or only touch the base of the bulb
when fitting.
Only use bulbs of the correct type.
If the new bulb still does not light up, consult
a qualified specialist workshop.
Bulbs and lamps are an important aspect of
vehicle safety. You must therefore make sure
that these function correctly at all times.
Have the headlamp setting checked regularly. 112
Replacing bulbs
Lights and windscreen wipers

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

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

Problem Possible causes/consequences and
M SolutionsVehicles 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 5th and 6th gear, you
must

press the shift lever to the right. Oth-
erwise, you could shift unintentionally into
3rd or 4th 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, 2 or 3
in
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 to 6 Forward gears150
Manual transmission
Driving and parking