warning lights MERCEDES-BENZ B-CLASS HATCHBACK 2015 User Guide

after an accident. Take this into account, par-
ticularly if a seat belt tensioner was triggered or
an airbag was deployed.
An electric motor is used by PRE-SAFE ®
to trig-
ger the tightening of the seat belt in hazardous
situations. This procedure is reversible.
If the belt tensioners are triggered or an airbag is
deployed, you will hear a bang, and a small
amount of powder may also be released. The
6 restraint system warning lamp lights up.
Only in rare cases will the bang affect your hear-
ing. In general, the powder released is not haz-
ardous to health but may cause short-term
breathing difficulties to persons suffering from
asthma or other pulmonary conditions. Provided it is safe to do so, you should leave the vehicle
immediately or open the window in order to pre- vent breathing difficulties.
Operation During the first stage of a collision, the restraint
system control unit evaluates important physi-
cal data relating to vehicle deceleration or accel-
eration, such as:
R duration
R direction
R intensity
Based on the evaluation of this data, the
restraint system control unit triggers the seat
belt tensioners in the event of a head-on or rear
collision.
A seat belt tensioner can only be triggered if:
R the ignition is switched on
R the components of the restraint system are
operational. You can find further information
under: "Restraint system warning lamp"
(Y page 34)
R the belt tongue has engaged in the belt buckle
of the respective front seat
The seat belt tensioners in the rear compart-
ment are triggered independently of the lock
status of the seat belts.
If the restraint system control unit detects a high severity accident, in certain head-on collisions,
additional components of the restraint system
are deployed independently of each other:
R front airbags and driver's kneebag
R windowbag, if the system determines that
deployment can offer additional protection to
that provided by the seat belt On vehicles with the automatic front-passenger
front airbag deactivation system: depending on the person in the front-passenger seat, the
front-passenger front airbag is either disabled or
enabled. The front-passenger front airbag can
only be deployed in an accident if the
PASSENGER AIR BAG ON indicator lamp is lit.
Observe the information on the PASSENGER AIR BAG indicator lamps (Y page 35).
Your vehicle has two-stage front airbags. In the
first deployment stage, the front airbag is filled
with propellant gas to reduce the risk of injuries. The front airbag is fully deployed if the second
deployment stage is activated within a few mil-
liseconds.
The activation threshold for the seat belt ten-
sioners and airbags is determined based on the
evaluation of the vehicle's rate of deceleration
or acceleration at various points in the vehicle.
This process is pre-emptive in nature. The trig-
gering/deployment process should take place
in good time at the start of the collision.
The rate of vehicle deceleration or acceleration
and the direction of the force are essentially
determined by:
R the distribution of forces during the collision
R the collision angle
R the deformation characteristics of the vehicle
R the characteristics of the object with which
the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a deci-
sive role in the deployment of an airbag, nor do
they provide an indication of airbag deployment.
The vehicle may be deformed significantly with-out an airbag being deployed. This is the case if
only parts which are relatively easily deformed
are affected and the rate of deceleration is not
high. Conversely, an airbag may be deployed
even though the vehicle suffers only minor
deformation. This is the case if, for example,
very rigid vehicle parts such as longitudinal body
members are hit, and sufficient deceleration
occurs as a result.
If the restraint system control unit detects a side impact, the applicable components of the
restraint system are activated independently of
each other.
R Sidebags on the side on which an impact
occurs, independent from the seat belt ten-
sioner and seat belt usage
Vehicles with the automatic front-passenger
airbag deactivation system: the sidebag on Occupant safety
47Safety Z

You can thus avoid the risks that could arise as
a result of:
R a child restraint system that is not detected
by the automatic front-passenger front airbag deactivation system
R the unintentional disabling of the front-
passenger front airbag
R the unsuitable positioning of the child
restraint system, e.g. too close to the dash-
board Please observe the warning notice on the front-
passenger sun visor, see the illustration. G
WARNING
If you secure a child on the co-driver's seat in a rearward-facing child restraint system and
the PASSENGER AIR BAG ON indicator lamp
lights up, the co-driver's airbag could be
deployed in the event of an accident. The childcould be struck by the airbag. There is an
increased risk of injury, possibly even fatal.
In this case, always ensure that the co-driver's
airbag is disabled. The PASSENGER AIRBAG
OFF indicator lamp must light up.
NEVER use a rearward facing child restraint on a seat protected by an ACTIVE AIRBAG in front of
it; DEATH or SERIOUS INJURY to the CHILD can
occur.
If the PASSENGER AIR BAG ON indicator lamp is lit, the front-passenger front airbag is enabled
(Y page 35). Vehicles without the automatic front-
passenger front airbag deactivation
system If the front-passenger seat of your vehicle is not
equipped with the automatic front-passenger
front airbag deactivation system, this is indica-
ted by a special sticker. The sticker is affixed to
the side of the dashboard on the front-
passenger side. The sticker is visible when you
open the front-passenger door.
If you turn the key to position 2in the ignition
lock, the PASSENGER AIR BAG OFF and
PASSENGER AIR BAG ON indicator lamps light
up briefly. However, they have no function and
do not indicate that there is an automatic front-
passenger front airbag deactivation system.
Always fit the rearward-facing restraint system
to a suitable rear seat in this case (Y page 54).
Observe the following information under "Rear-
ward-facing child restraint system" and
"Forward-facing child restraint system" as well
as information on the suitable positioning of the child restraint system (Y page 54).
Rearward-facing child restraint system If it is absolutely necessary to fit a rearward-
facing child restraint system to the front-
passenger seat, always make sure that the
front-passenger front airbag is disabled. Only if
the PASSENGER AIR BAG OFF indicator lamp is
lit continuously (Y page 35)is the front-
passenger front airbag disabled.
Always observe the information on suitable
positioning of the child restraint system
(Y page 54) in addition to the child restraint
system manufacturer's installation and operat-
ing instructions. Children in the vehicle
53Safety Z

Override feature for the rear side win-
dows X
To enable/disable: press button:.
If indicator lamp ;is lit, operation of the rear
side windows is disabled. Operation is only
possible using the switches in the driver's
door. If indicator lamp ;is off, operation is
possible using the switches in the rear com-
partment. Pets in the vehicle
G
WARNING
If you leave animals unsupervised or unse-
cured in the vehicle, they may push a button
or a switch, for example.
They could:
R activate vehicle equipment and become
trapped, for example
R switch vehicle systems on or off, thus
endangering other road users
In the event of an accident, sudden braking or
abrupt changes of direction, unsecured ani-
mals could be flung around the vehicle, injur-
ing the vehicle occupants. There is a risk of an accident and injury.
Never leave animals unattended in the vehi-
cle. Always secure animals correctly during a
journey, e.g. in an animal transport box. Driving safety systems
Driving safety systems overview
In this section, you will find information about
the following driving safety systems:
R ABS (A nti-lock Braking System)
(Y page 61)
R BAS (Brake AssistSystem) (Y page 62)
R COLLISION PREVENTION ASSIST PLUS
(Y page 62)
R Adaptive brake lights (Y page 65)
R ESP ®
(Electronic StabilityProgram)
(Y page 65)
R EBD (e lectronic brake force distribution)
(Y page 66)
R ADAPTIVE BRAKE (Y page 67)
R STEER CONTROL (Y page 67) Important safety notes
If you fail to adapt your driving style or if you are
inattentive, the driving safety systems can nei-
ther reduce the risk of an accident nor override
the laws of physics. Driving safety systems are
merely aids designed to assist driving. You are
responsible for maintaining the distance to the
vehicle in front, for vehicle speed, for braking in
good time, and for staying in lane. Always adapt your driving style to suit the prevailing road and weather conditions and maintain a safe distance
from the vehicle in front. Drive carefully.
The driving safety systems described only work as effectively as possible when there is ade-
quate contact between the tyres and the road
surface. Please pay special attention to the
notes on tyres, recommended minimum tyre
tread depths etc. (Y page 266).
In wintry driving conditions, always use winter
tyres (M+S tyres) and, if necessary, snow
chains. Only in this way will the driving safety
systems described in this section work as effec-
tively as possible. ABS (Anti-lock Braking System)
General notes ABS regulates brake pressure in such a way that
the wheels do not lock when you brake. This Driving safety systems
61Safety Z

allows you to continue steering the vehicle when
braking.
The ! ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
ABS works from a speed of about 8 km/h,
regardless of road-surface conditions. ABS
works on slippery surfaces, even when you only
brake gently.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 61). G
WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid- ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
If ABS is malfunctioning, other systems, includ-
ing driving safety systems, will also become
inoperative. Observe the information on the ABS warning lamp (Y page 216) and display mes-
sages which may be shown in the instrument
cluster (Y page 190).
Brakes X
If ABS intervenes: continue to depress the
brake pedal with force until the braking sit-
uation is over.
X To make a full brake application: depress
the brake pedal with full force.
If ABS intervenes when braking, you will feel a
pulsing in the brake pedal.
The pulsating brake pedal can be an indication
of hazardous road conditions; this serves as a
reminder to take extra care while driving. BAS (Brake Assist)
General notes BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 61). G
WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking X
Keep the brake pedal depressed firmly until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. COLLISION PREVENTION ASSIST
PLUS
General notes i
Observe the "Important safety notes" sec-
tion (Y page 61).
COLLISION PREVENTION ASSIST PLUS consists of a distance warning function with an autono-
mous braking function and Adaptive Brake
Assist.
COLLISION PREVENTION ASSIST PLUS can help you to minimise the risk of a collision with the
vehicle in front or reduce the effects of such a
collision.
If COLLISION PREVENTION ASSIST PLUS
detects that there is a risk of a collision, you will
be warned visually and acoustically. If you do not react to the visual and audible collision warning,autonomous braking can be initiated in critical
situations. If you apply the brake yourself in a 62
Driving safety systemsSafety

critical situation, the COLLISION PREVENTION
ASSIST PLUS Adaptive Brake Assist assists you.
Important safety notes Detection of hazardous situations can be par-
ticularly impaired by:
R
dirt on the sensors or obscured sensors
R snow or heavy rain
R interference by other radar sources
R strong radar reflections, for example, in multi-
storey car parks
R a narrow vehicle travelling in front, e.g. a
motorcycle
R a vehicle travelling in front on a different line
R new vehicles or after a service on the COLLI-
SION PREVENTION ASSIST PLUS system
Observe the important safety notes in the
"Running-in notes" section (Y page 125).
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow speeds where there is no visible damage to thefront of the vehicle.
Activating/deactivating The COLLISION PREVENTION ASSIST PLUS is
automatically active after switching on the igni-
tion.
You can activate or deactivate COLLISION PRE-
VENTION ASSIST PLUS in the on-board com-
puter (Y page 183). When deactivated, the dis-
tance warning function and the autonomous
braking function are also deactivated.
If COLLISION PREVENTION ASSIST PLUS is
deactivated, the æsymbol appears in the
assistance graphics display.
Distance warning function General notes
The distance warning function can help you to
minimise the risk of a collision with the vehicle 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 61). 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 warning at speeds:
R of approximately 30 km/h or more, if, over
several seconds, the distance maintained to
the vehicle travelling in front is insufficient.
The · distance warning lamp then lights
up in the instrument cluster.
R of approximately 7 km/h or more, if you rap-
idly approach a vehicle in front. An intermit-
tent warning tone will then sound, and the
· distance warning lamp will light up in the
instrument cluster. Driving safety systems
63Safety Z

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 conditions
may also cause Brake Assist to intervene.
If Adaptive Brake Assist is not available due to a malfunction in the radar sensor system, the
brake system remains available with full brake
boosting effect and BAS. Adaptive brake lights
The adaptive brake lights warn following traffic
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 warning
lamps are activated automatically. If the brakes
are applied again, the brake lamps light up con- tinuously. 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 100). 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 vehi- cle 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 (Electronic Traction System) i
Observe the "Important safety notes" sec-
tion (Y page 61).
ETS traction control is part 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 transfer-
red to the wheel or wheels with traction.
Traction control remains active if you deactivate
ESP ®
.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 61). 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 towing your vehicle with the front axle
raised, observe the notes on ESP ®
(Y page 262).
When towing your vehicle away with the rear
axle raised, observe the notes on ESP ®
(Y page 262).
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. Driving safety systems
65Safety Z

Observe the information on warning lamps
(Y page 218) and display messages which may
be shown in the instrument cluster
(Y page 190).
Only use wheels with the recommended tyre
sizes. Only then will ESP ®
function properly.
Characteristics of ESP ®Characteristics of ESP
®
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 acceler-
ator pedal as far as is necessary.
X Adapt your driving style to suit the prevailing
road and weather conditions.
Deactivating/activating ESP ®Important safety notes
You can select between the following statuses
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 follow-
ing 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 vehicle
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 182).
ESP ®
deactivated:
The å ESP®
OFF warning lamp in the instru-
ment cluster lights up.
ESP ®
activated:
The å ESP®
OFF warning lamp in the instru-
ment cluster goes out.
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 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 cutting
action for better traction on loose surfaces.
R Traction control is still activated
R COLLISION PREVENTION ASSIST is no longer
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 assistance
from ESP ®
R ESP ®
still provides support when you brake
firmly EBD (electronic brake force distribu-
tion)
General notes EBD monitors and controls the brake pressure
on the rear wheels to improve driving stability
while braking.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 61). 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. 66
Driving safety systemsSafety

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 ignition
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 charge socket flap will not be
unlocked automatically.
Removing the emergency key element X
Push release catch :in the direction of the
arrow and, at the same time, remove emer-
gency key element ;from the key.
Further information about:
R unlocking the driver's door (Y page 80)
R unlocking the luggage compartment
(Y page 81)
R locking the vehicle (Y page 80)
Inserting the emergency key element X
Push emergency key element ;completely
into the key until it engages and release
catch :is back in its basic position. 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. H
Environmental note Batteries contain pollutants.
It is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in anenvironmentally responsible
recycling system. Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-
lection point for used batter-
ies.
Mercedes-Benz recommends that you have the
battery replaced at a qualified specialist work-
shop.
Checking the battery X
Press the &or% button.
The battery is working properly if battery
check lamp :lights up briefly. 74
KeyOpening and closing

Mirrors
Rear-view mirror
X
Anti-dazzle mode: pivot anti-dazzle
switch :forwards or back. Exterior mirrors
Adjusting the exterior mirrors G
WARNING
You could lose control of your vehicle if you do the following while driving:
R adjust the driver's seat, head restraint,
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 mirror and fasten your seat belt before starting the vehicle's drive system. G
WARNING
The exterior mirrors reduce the size of the
image. Objects visible in the mirrors are
closer than they appear. You could misjudge
the distance from road users driving behind
you when changing lanes, for instance. There is a risk of an accident.
You should therefore always look over your
shoulder to determine the actual distance
from road users driving behind you. X
Turn the key to position 1or 2in the ignition
lock (Y page 126).
X Press button :for the left-hand exterior mir-
ror or button ;for the right-hand exterior
mirror.
The indicator lamp in the corresponding but-
ton lights up in red.
The indicator lamp goes out again after some
time. You can adjust the selected mirror using
adjustment button =as long as the indicator
lamp is lit.
X Press adjustment button =up, down, or to
the left or right until you have adjusted the
exterior mirror to the correct position. You
should have a good overview of traffic condi-
tions.
The convex exterior mirrors provide a larger field
of vision.
After the engine has been started, the exterior
mirrors are automatically heated at low outside temperatures. Heating takes a maximum of ten
minutes.
i The exterior mirrors can also be heated
manually by switching on the rear window
heating. Mirrors
93Seats, steering wheel and mirrors Z

Useful information
i This Owner's Manual describes all models,
series and optional equipment for your vehi-
cle that were available at the time of going to
press. National variations are possible. Note
that your vehicle may not be equipped with all
of the functions described. This is also the
case for systems and functions relevant to
safety.
i Read the information on qualified specialist
workshops: (Y page 23). Exterior lighting
General notes
For reasons of safety, Mercedes-Benz recom-
mends that you drive with the lights switched on
even during the daytime. In some countries,
operation of the headlamps varies due to legal
requirements and self-imposed obligations. Driving abroad
General notes If your journey takes you to countries where
vehicles are driven on the opposite side of the
road to the country in which the vehicle is reg-
istered, your headlamps must be switched to
symmetrical dipped beam as soon as possible
after crossing the border (only vehicles with
Intelligent Light System). This prevents oncom-
ing traffic from being dazzled. Symmetrical
lights do not illuminate as large an area of the
edge of the carriageway.
Vehicles with bi-xenon or halogen head-
lamps It is not necessary to switch your headlamps to
symmetrical dipped beam when driving in coun- tries where vehicles are driven on the opposite
side of the road to the country in which the vehi-
cle is registered. Legal requirements are fulfilled
without switching the headlamps to symmetri-
cal dipped beam. Vehicles with Intelligent Light System Before crossing the border, set the headlamps
to symmetrical dipped beam and after returning
back to asymmetrical dipped beam via the
"Dipped-beam headlamps for driving on the
right/left" function in the on-board computer
(Y page 187).
If the headlamps are converted to symmetrical
dipped beam, the "motorway mode" and "exten- ded range foglamps" functions are not available. Setting the exterior lighting
Setting options Exterior lighting can be set using the:
R light switch
R combination switch (Y page 99)
R headlamp range adjustment (only vehicles
with halogen headlamps) (Y page 99)
R on-board computer (Y page 186)
Light switch Operation
1
W
Left-hand parking lamps
2 X
Right-hand parking lamps
3 T
Side lamps, licence plate and instru-
ment cluster lighting
4 Ã
Automatic headlamp mode, controlled
by the light sensor
5L Dipped-beam/main-beam headlamps
B R
Rear foglamp
If you hear a warning tone when you leave the
vehicle, the lights may still be switched on.
X Turn the light switch to the Ãposition. Exterior lighting
97Lights and windscreen wipers