warning MERCEDES-BENZ A-CLASS HATCHBACK 2015 Service Manual

R
a vehicle travelling in front on a different
line
R new vehicles or after a service on the COL-
LISION PREVENTION ASSIST PLUS system
Observe the important safety notes in the
"Running-in notes" section (Y page 156).
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at slow speeds where there is no visible
damage to the front of the vehicle.
Activating/deactivating The COLLISION PREVENTION ASSIST PLUS is
automatically active after switching on the
ignition.
You can activate or deactivate COLLISION
PREVENTION ASSIST PLUS in the on-board
computer (Y page 249). When deactivated,
the distance warning function and the auton- omous braking function are also deactivated.
Vehicles with black and white multifunc-
tion display: when COLLISION PREVENTION
ASSIST PLUS is activated, the multifunction
display in the status overview shows the Ä
symbol.
Vehicles with colour multifunction dis-
play: when COLLISION PREVENTION ASSIST
PLUS is deactivated, the multifunction dis-
play in the assistance graphic shows the æ
symbol.
Distance warning function General notes
The distance warning function can help you to
minimise the risk of a collision with the vehi-
cle in front or reduce the effects of such a
collision. If the distance warning function
detects that there is a risk of a collision, you
will be warned visually and acoustically. Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 69). G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. G
WARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation; do not rely on the distance warning
function alone.
Function
The distance warning function issues a warn- ing at speeds:
R of approximately 30 km/h or more, if, over
several seconds, the distance maintained
to the vehicle travelling in front is insuffi-
cient. The ·distance warning lamp
then lights up in the instrument cluster.
R of approximately 7 km/h or more, if you
rapidly approach a vehicle in front. An inter-
mittent warning tone will then sound, and
the · distance warning lamp will light
up in the instrument cluster. Driving safety systems
71Safety Z

X
Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause the system to display a
warning.
With the help of the radar sensor system, the distance warning function can detect obsta-
cles that are in the path of your vehicle for an
extended period of time.
Up to a speed of approximately 70 km/h, the
distance warning function can also react to
stationary obstacles, such as stopped or
parked vehicles.
Autonomous braking function If the driver does not react to the distance
warning signal in a critical situation, COLLI-
SION PREVENTION ASSIST PLUS can assist
with the autonomous braking function.
The autonomous braking function:
R gives the driver more time to react to criti-
cal driving situations
R can help the driver to avoid an accident or
R reduces the effects of an accident
Due to the nature of the system, complicated but non-critical driving conditions may also
cause the Autonomous Braking function to
intervene.
If the autonomous braking function demands
particularly high braking force, preventative
passenger protection measures (PRE-SAFE ®
)
are activated simultaneously (Y page 56).
Adaptive Brake Assist General notes
i Observe the "Important safety notes" sec-
tion (Y page 69).
With the help of Adaptive Brake Assist, the
distance warning signal can detect obstacles that are in the path of your vehicle for an
extended period of time.
If Adaptive Brake Assist detects a risk of col-
lision with the vehicle in front, it calculates
the braking force necessary to avoid a colli-
sion. If you apply the brakes forcefully, Adap-
tive Brake Assist will automatically increase
the braking force to a level suitable for the
traffic conditions.
Adaptive Brake Assist provides braking assis- tance in hazardous situations at speeds
above 7 km/h. It uses radar sensor technol-
ogy to assess the traffic situation.
Up to a speed of approximately 250 km/h,
Adaptive Brake Assist is capable of reacting
to moving objects that have already been
detected as such at least once over the period
of observation.
Up to a speed of approximately 70 km/h,
Adaptive Brake Assist reacts to stationary
obstacles.
If Adaptive Brake Assist demands particularly high braking force, preventative passenger
protection measures (PRE-SAFE ®
) are activa-
ted simultaneously (Y page 56).
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal
R there is no longer any danger of a collision
R no obstacle is detected in front of your
vehicle
Adaptive Brake Assist is then deactivated.
Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 69). G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions. 72
Driving safety systemsSafety

In such cases, Adaptive Brake Assist can:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation. G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, the Adaptive Brake Assist may not intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause Brake Assist to inter-
vene.
If Adaptive Brake Assist is not available due to a malfunction in the radar sensor system, thebrake system remains available with full
brake boosting effect and BAS. Adaptive brake lights
The adaptive brake lights warn following traf- fic in an emergency braking situation:
R by flashing brake lamps
R the hazard warning lamps are activated
If you brake sharply from a speed of more
than 50 km/h or if braking is assisted by BAS
or BAS PLUS, the brake lamps flash rapidly. In
this way, traffic travelling behind you is
warned in an even more noticeable 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 button (Y page 123). ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes" sec-
tion (Y page 69).
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 69).
ETS traction control is part of ESP ®
. On vehi-
cles with 4MATIC, 4ETS is a component of
ESP ®
.
Traction control brakes the drive wheels indi-
vidually 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 trans-
ferred to the wheel or wheels with traction.
Traction control remains active if you deacti-
vate ESP ®
.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 69). Driving safety systems
73Safety Z

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.
Vehicles without 4MATIC: when towing
away your vehicle with the front axle raised,
please observe the notes on ESP ®
(Y page 352).
If the å ESP®
OFF warning lamp lights up
continuously, ESP ®
is deactivated.
If the ÷ ESP®
warning lamp and the å
warning lamp are lit continuously, ESP ®
is not
available due to a malfunction.
Observe the information on warning lamps
(Y page 297) and display messages which
may be shown in the instrument cluster
(Y page 258).
Only use wheels with the recommended tyre
sizes. Only then will ESP ®
function properly.
Characteristics of ESP ®General notes
If the
÷ ESP warning lamp goes out before
beginning the journey, ESP ®
is automatically
active.
If ESP ®
intervenes, the ÷ESP®
warning
lamp flashes in the instrument cluster.
If ESP ®
intervenes:
X Do not deactivate ESP ®
under any circum-
stances.
X When pulling away, only depress the accel-
erator pedal as far as is necessary.
X Adapt your driving style to suit the prevail-
ing road and weather conditions.
ECO start/stop function
The ECO start/stop function switches the
engine off automatically if the vehicle stops
moving. When pulling away again, the engine starts automatically. ESP
®
remains in its pre-
viously selected status. Example:if ESP®
was deactivated before the engine was
switched off, ESP ®
remains deactivated when
the engine is switched on again.
Deactivating/activating ESP ®
(except
Mercedes‑AMG vehicles) Important safety notes
You can select between the following sta-
tuses of ESP ®
:
R ESP ®
is activated
R ESP ®
is deactivated 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
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilise the vehi-
cle if the vehicle starts to skid or a wheel
starts to spin.
Deactivating/activating ESP ®
You can deactivate or activate ESP ®
via the
on-board computer (Y page 248).
ESP ®
deactivated:
The å ESP®
OFF warning lamp in the
instrument cluster lights up.
ESP ®
activated:
The å ESP®
OFF warning lamp in the
instrument cluster goes out. 74
Driving safety systemsSafety

Characteristics when ESP
®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ESP®
warning lamp in
the instrument cluster flashes. In such situa-
tions, ESP ®
will not stabilise the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability
R Engine torque is no longer limited and the
drive wheels are able to spin
The spinning of the wheels results in a cut- ting action for better traction on loose sur-faces.
R Traction control is still activated
R COLLISION PREVENTION ASSIST is no lon-
ger available; nor is it activated if you brake
firmly with assistance from ESP ®
R PRE-SAFE ®
is no longer available; it is also
not activated if you brake firmly with assis-
tance from ESP ®
R ESP ®
still provides support when you brake
firmly
Deactivating/activating ESP ®
(Mercedes ‑AMG vehicles) Important safety notes
i Observe the "Important safety notes" sec-
tion (Y page 69).
You can select between the following sta-
tuses of ESP ®
:
R ESP ®
is activated
R SPORT handling mode is activated
R ESP ®
is deactivated
ESP ®
is activated every time the engine is
switched on, regardless of whether ESP ®
was
deactivated before the engine was switched
off. G
WARNING
When SPORT handling mode is activated,
there is a greater risk of skidding and acci-
dents. Only activate SPORT handling mode in the sit-
uations described in the following. 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.
In the following situations, it may be better to activate SPORT handling mode or deactivate
ESP ®
:
R when using snow chains
R in deep snow
R on sand or gravel
R on specially designated roads when the
vehicle's own oversteering and understeer-
ing characteristics are desired
Driving in SPORT handling mode or without
ESP ®
requires an extremely qualified and
experienced driver.
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilise the vehi-
cle if the vehicle starts to skid or a wheel
starts to spin.
Deactivating/activating ESP ® X
To activate SPORT handling mode:
briefly press button :.
The M handling mode warning lamp in
the instrument cluster lights up. The Driving safety systems
75Safety Z

SPORT handling mode
SPORT handling mode
message appears
in the multifunction display.
X To deactivate SPORT handling mode:
briefly press button :.
The M handling mode warning lamp in
the instrument cluster goes out.
X To deactivate ESP ®
:press button :until
the å ESP®
OFF warning lamp lights up
in the instrument cluster.
The ÷ OFF OFFmessage appears in the mul-
tifunction display.
X To activate ESP ®
:briefly press button :.
The å ESP®
OFF warning lamp in the
instrument cluster goes out. The ÷
ESP ®
ON
ON message appears in the multifunc-
tion display.
Characteristics of activated SPORT han-
dling mode
If SPORT handling mode is activated and one or more wheels start to spin, the ÷ESP®
warning lamp in the instrument cluster
flashes. ESP ®
only stabilises the vehicle to a
limited degree.
When SPORT handling mode is activated:
R ESP ®
only improves driving stability to a
limited degree
R Traction control is still activated
R Engine torque is no longer limited and the
drive wheels are able to spin
The spinning of the wheels results in a cut-
ting action for better traction on loose sur-faces.
R ESP ®
still provides support when you brake
firmly
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ESP®
warning lamp in
the instrument cluster does not flash. In such
situations, ESP ®
will not stabilise the vehicle. If you deactivate ESP
®
:
R ESP ®
no longer improves driving stability
R Engine torque is no longer limited and the
drive wheels are able to spin
The spinning of the wheels results in a cut-
ting action for better traction on loose sur- faces.
R Traction control is still activated
R COLLISION PREVENTION ASSIST is no lon-
ger available; nor is it activated if you brake
firmly with assistance from ESP ®
R PRE-SAFE ®
is no longer available; it is also
not activated if you brake firmly with assis-
tance from ESP ®
R ESP ®
still provides support when you brake
firmly
ESP ®
trailer stabilisation General notes
If your vehicle/trailer combination begins to
lurch, ESP
®
assists you in this situation. ESP ®
slows the vehicle down by braking and limit-
ing the engine output until the vehicle/trailer combination has stabilised.
Important safety notes G
WARNING
If road and weather conditions are poor,
trailer stabilisation will not be able to prevent the vehicle/trailer combination from swerv-
ing. Trailers with a high centre of gravity can
tip over before ESP ®
can detect this. There is
a risk of an accident.
Always adapt your driving style to the prevail-
ing road and weather conditions.
If your vehicle/trailer combination begins to
lurch, you can only stabilise the vehicle/
trailer combination by depressing the brake
firmly.
ESP ®
trailer stabilisation is active above
speeds of approximately 65 km/h. 76
Driving safety systemsSafety

ESP
®
trailer stabilisation does not work if
ESP ®
is deactivated or disabled because of a
malfunction. EBD (electronic brake force distribu-
tion)
General notes EBD monitors and controls the brake pres-
sure on the rear wheels to improve driving
stability while braking.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 69). G
WARNING
If EBD is malfunctioning, the rear wheels can
lock, e.g. under full braking. This increases 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 295) as well as dis-
play messages (Y page 260). 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 204)and
hill start assist (Y page 161). STEER CONTROL
General notes 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
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 69).
No steering support is provided from STEER
CONTROL, if:
R ESP ®
is malfunctioning
R the steering is faulty
If ESP ®
is malfunctioning, you will be assisted
further by the electrical power steering. Protection against theft
Immobiliser
The immobiliser prevents your vehicle from
being started without the correct key.
X To activate with the key: remove the key
from the ignition lock.
X To activate with KEYLESS-GO start func-
tion or KEYLESS-GO: switch the ignition
off and open the driver's door.
X To deactivate: switch on the ignition.
When leaving the vehicle, always take the key with you and lock the vehicle. Anyone can
start the engine if a valid key has been left
inside the vehicle.
i The immobiliser is always deactivated
when you start the engine. Protection against theft
77Safety Z

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). Key
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle, they could:
R open doors, thereby endangering other per-
sons or road users
R get out and be struck by oncoming traffic
R operate vehicle equipment and become
trapped, for example
In addition, the children could also set the
vehicle in motion, for example, if they:
R release the parking brake
R shift the automatic transmission out of park
position P or shift 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 and animals unattended in the vehi-
cle. Keep the keys out of the reach of children. G
WARNING
If you attach heavy or large objects to the key, the key could be unintentionally turned in the
ignition lock. This could cause the engine to
be switched off. There is a risk of an accident. Do not attach any heavy or large objects to the
key. Remove any bulky keyrings before insert-
ing the key into the ignition lock.
! Keep the key away from strong magnetic
fields. Otherwise, the remote control func-
tion could be affected.
Strong magnetic fields can occur in the
vicinity of powerful electrical installations.
Do not keep the key:
R with electronic devices, e.g. a mobile
phone or another key
R with metallic objects, e.g. coins or metal
film
R inside metallic objects, e.g. a metal case
Vehicles with KEYLESS-GO start function: do not keep the key in the luggage compart-
ment. Otherwise, the key may not be detec-
ted, e.g. when starting the engine using the
Start/Stop button.
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 from the out-
side, the double lock function is activated as
standard. It is then not possible to open the
doors from inside the vehicle. You can deac-
tivate the double lock function by deactivat-
ing the interior motion sensor (Y page 80).
The doors can then be opened from the inside after the vehicle has been locked from the
outside. You can open the rear doors from
inside the vehicle if they are not secured by
the child-proof locks (Y page 68). The anti-
theft alarm system is triggered if the door is 82
KeyOpening and closing

opened from the inside. Switch off the alarm
(Y page 78). 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. Key functions
:
& Locks the vehicle
; % Unlocks the vehicle
X To unlock centrally: press the%but-
ton.
If you do not open the vehicle within
approximately 40 seconds of unlocking:
R the vehicle locks again
R protection against theft is reactivated
X To lock: press the &button.
The key centrally locks/unlocks: R the doors
R the tailgate
R the fuel filler flap
When unlocking, the turn signals flash once.
When locking, they flash three times.
When the locator lighting is activated in Audio
20/COMAND Online, it lights up when it is
dark after the vehicle is unlocked with the
remote control (see separate operating
instructions). You can also set an audible signal to confirm
that the vehicle has been locked. The audiblesignal can be activated or deactivated using
the on-board computer (Y page 252). KEYLESS-GO
General notes Bear in mind that the engine can be started by
any of the vehicle occupants if there is a key
in the vehicle.
Locking and unlocking You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you need to carry
the key with you. You can combine the KEY-
LESS-GO functions with the functions of a
conventional key. Unlock the vehicle by using
KEYLESS-GO, for instance, and lock it using
the & button on the key.
The driver's door and the door at which the
handle is used must both be closed. The key
must be outside the vehicle. When locking or unlocking with KEYLESS-GO, the distance
between the key and the corresponding door
handle must not be greater than 1 m.
A check which periodically establishes a radio connection between the vehicle and the key
determines whether a valid key is in the vehi-
cle. This occurs, for example:
R when starting the engine
R whilst driving
R when the external door handles are
touched
R during convenience closing Key
83Opening and closing Z

The KEYLESS-GO function is changed as fol-
lows:
X To unlock the driver's door: touch the
inner surface of the door handle on the
driver's door.
X To unlock centrally: touch the inner sur-
face of the door handle on the front-
passenger door or the rear door.
X To lock centrally: touch the outer sensor
surface on one of the door handles.
X To restore the factory settings: press
and hold down the %and& buttons
simultaneously for approximately six sec-
onds until the battery check lamp flashes
twice (Y page 86). Emergency key element
General notes If the vehicle can no longer be unlocked with
the key or KEYLESS-GO, use the emergency
key element.
If you use the emergency key element to
unlock and open the driver's door or the tail-
gate, the anti-theft alarm system will be trig-
gered (Y page 78).
There are several ways to deactivate the
alarm:
X To deactivate the alarm with the key:
press the %or& button on the key.
or X Insert the key into the ignition lock.
or
X To deactivate the alarm with KEYLESS-
GO: press the Start/Stop button in the igni-
tion lock. The key must be in the vehicle.
or X Lock or unlock the vehicle using KEYLESS-
GO. The key must be outside the vehicle.
If you unlock the vehicle using the emergency
key element, the fuel filler flap will not be
unlocked automatically. X
To unlock the fuel filler flap: insert the
key into the ignition lock.
Removing the emergency key element X
Push release catch :in the direction of
the arrow and, at the same time, remove
emergency key element ;from the key.
Further information about:
R unlocking the driver's door (Y page 91)
R unlocking the luggage compartment
(Y page 93)
R locking the vehicle (Y page 92)
Inserting the emergency key element X
Push emergency key element ;com-
pletely into the key until it engages and
release catch :is back in its basic posi-
tion. Battery of the key
Important safety notes G
WARNING
Batteries contain toxic and corrosive substan- ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatal injury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention immediately. Key
85Opening and closing Z