sensor MERCEDES-BENZ B-CLASS HATCHBACK 2014 User Guide

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
Please observe the information in the sec-
tion on running-in the vehicle
(Y page 158).
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.
Distance warning function Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 73).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
X To activate/deactivate: activate or deac-
tivate the distance warning function in the
on-board computer (Y page 244).
Vehicles with a black and white multi-
function display: when the distance warning
function is activated, the Äsymbol
appears in the status overview in the multi-
function display.
Vehicles with a colour multifunction dis-
play: when the distance warning function is
deactivated, the æsymbol appears in the
assistance graphics in the multifunction dis-
play.
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.
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.
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. Driving safety systems
75Safety Z

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.
If you approach an obstacle and the distance
warning function detects a risk of a collision, the system will alert you both visually and
acoustically.
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
Vehicles without DISTRONIC PLUS: the
autonomous braking function is available in
the following speed ranges:
R 7 - 105 km/h for moving objects
R 7 - 50 km/h for stationary objects
Vehicles with DISTRONIC PLUS: the auton-
omous braking function is available in the fol- lowing speed ranges:
R 7 - 200 km/h for moving objects
R 7 - 50 km/h for stationary objects
If the autonomous braking function demands
particularly high braking force, preventative
passenger protection measures (PRE-SAFE ®
)
are activated simultaneously.
Adaptive Brake Assist i
Observe the "Important safety notes" sec-
tion (Y page 73).
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. G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
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.
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. 76
Driving safety systemsSafety

Tow-away protection remains deactivated
until:
R the vehicle is unlocked again
R a door is opened and closed again and
R the vehicle is locked again
To prevent a false alarm, deactivate tow-away protection if you lock your vehicle and it:
R is being transported
R is being loaded onto a ferry or car trans-
porter, for example
R is parked on a movable surface, e.g. in a
split-level garage Interior motion sensor
Function When the interior motion sensor is primed, a
visual and audible alarm is triggered if move- ment is detected in the vehicle interior. This
can occur if someone reaches into the vehicle
interior, for example.
Priming X
Make sure that:
R the side windows are closed
R the panorama sliding sunroof is closed
R there are no objects, e.g. mascots, hang-
ing on the rear-view mirror or on the grab handles on the roof trim
This will prevent false alarms.
X Make sure that:
R the doors are closed
R the panorama sliding sunroof is closed
R the tailgate is closed
Only then is the interior motion sensor
primed.
X Lock the vehicle with the key or KEYLESS-
GO.
The interior motion sensor is primed after
approximately 30 seconds. Switching off X
Unlock the vehicle with the key or KEY-
LESS-GO.
or X Insert the key into the ignition lock.
or X Press the Start/Stop button.
The key must be in the vehicle.
The interior motion sensor is automatically switched off.
Deactivating X
Remove the key from the ignition lock.
or X Vehicles with KEYLESS-GO start func-
tion or KEYLESS-GO: switch off the engine
using the Start/Stop button and open the
driver's door.
X Press button :.
Indicator lamp ;flashes several times in
rapid succession.
X Lock the vehicle with the key or KEYLESS-
GO.
The interior motion sensor is deactivated.
The interior motion sensor remains deactiva- ted until:
R the vehicle is unlocked again and
R a door is opened and closed again and
R the vehicle is locked again 82
Protection against theftSafety

To prevent a false alarm, deactivate the inte-
rior motion sensor if you lock your vehicle
and:
R people or animals remain in the vehicle
R the panorama sliding sunroof remains open
R the side windows remain open
i UK only:
your vehicle is equipped with a
double-lock function. The doors cannot be
opened from the inside if the vehicle has
been locked with the key (Y page 93).
Deactivate the interior motion sensor
before you lock the vehicle with the key.
The doors can then be opened from the
inside after the vehicle has been locked
from the outside with the key. Observe the
"Important safety notes" (Y page 93). Protection against theft
83Safety 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 82).
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 72). The anti-
theft alarm system is triggered if the door is 86
KeyOpening and closing

X
To unlock the vehicle: touch the inner
surface of the door handle.
X To lock the vehicle: touch sensor sur-
face :or;.
Make sure that you do not touch the inner
surface of the door handle.
X Convenience closing feature: touch
recessed sensor surface ;for an exten-
ded period.
For further information on the convenience closing feature (Y page 99).X
To unlock the tailgate: pull the tailgate
handle.
Deactivating and activating If you do not intend to use the vehicle for an
extended period of time, you can deactivate
KEYLESS-GO. The key will then use very little power, thereby conserving battery power. For
the purposes of activation/deactivation, the
vehicle does not have to be nearby. X
To deactivate: press the&button on
the key twice in rapid succession.
The battery check lamp of the key
(Y page 90) lights up twice briefly and
KEYLESS-GO is deactivated.
X To activate: press any button on the key or
insert the key into the ignition lock.
KEYLESS-GO and all of its associated fea-
tures are available again. KEYLESS-GO start function
Bear in mind that the engine can be started by any of the vehicle occupants if there is a key
in the vehicle. Changing the settings of the locking
system
You can change the settings of the locking
system. This means that only the driver's door and the fuel filler flap are unlocked when the
vehicle is unlocked. This is useful if you fre-
quently travel alone.
X To change the setting: simultaneously
press the %and& buttons for
approximately 6 seconds until the battery
check lamp (Y page 90) flashes twice.
i If the setting of the locking system is
changed within the signal range of the vehi- cle, pressing the &or% button:
R locks or
R unlocks the vehicle
The key now functions as follows:
X To unlock the driver's door: press the
% button once.
X To unlock centrally: press the%but-
ton twice.
X To lock centrally: press the&button. 88
KeyOpening and closing

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: simulta-
neously press the %and& buttons
for approximately 6 seconds until the bat-
tery check lamp flashes twice
(Y page 90). Emergency key element
General notes If the vehicle can no longer be locked or
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 80).
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 95)
R unlocking the luggage compartment
(Y page 97)
R locking the vehicle (Y page 96)
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
89Opening and closing Z

Problem
Possible causes/consequences and
M
MSolutions You have lost a key. X
Have the key deactivated at a qualified specialist workshop.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. You have lost the emer-
gency key element. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. Doors
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.
Stow luggage or loads preferably in the lug-
gage compartment. Observe the loading
guidelines (Y page 298).
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,
the double lock function is activated as stand-
ard. It is then not possible to open the doors
from inside the vehicle. You can deactivate
the double lock function by deactivating the
interior motion sensor (Y page 82). 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 vehi- cle if they are not secured by the child-proof
locks (Y page 72). The anti-theft alarm system
is triggered if the door is opened from the
inside. Switch off the alarm (Y page 80). Unlocking and opening the doors
from the inside
X
Pull door handle ;.
If the door is locked, locking knob :pops
up. The door is unlocked and opens. Doors
93Opening and closing Z

For all countries except the United King-
dom:
You can open a door from inside the vehicle
even if it has been locked. You can only open
the rear doors from inside the vehicle if they
are not secured by the child-proof locks
(Y page 72).
If the vehicle has previously been locked with
the key from the outside, opening a door from the inside will trigger the anti-theft alarm sys-
tem. Switch off the alarm (Y page 80).
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 82).
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 72). The anti-
theft alarm system is triggered if the door is
opened from the inside. Switch off the alarm
(Y page 80). Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle
from the inside. This can be useful if you wish to lock the vehicle before pulling away, for
example. X
To unlock: press button :.
X To lock: press button ;.
If all the doors and the tailgate are closed,
the vehicle locks.
This does not lock or unlock the fuel filler flap. You cannot unlock the vehicle centrally from
the inside if the vehicle has been locked with
the key or KEYLESS-GO.
For all countries except the United King-
dom:
You can open a door from inside the vehicle
even if it has been locked.
If the vehicle has previously been locked with the key from the outside, opening a door from
the inside will trigger the anti-theft alarm sys- tem. Switch off the alarm (Y page 80).
You can open the rear doors from inside the
vehicle if they are not secured by the child-
proof locks (Y page 72).
When a locked door is opened from inside the vehicle, the previous unlocking process will
be observed if the vehicle has been:
R locked with the locking button for the cen-
tral locking or
R locked automatically
The vehicle will be fully unlocked if it had pre- viously been fully unlocked. Only the door
which has been opened from the inside is
unlocked if only the driver's door had been
previously unlocked.
Only for the United Kingdom: if the vehicle
has been locked with the key, the double lock
function is activated as standard. It is then not possible to open the doors from inside the 94
DoorsOpening and closing

vehicle. You can deactivate the double lock
function by deactivating the interior motion
sensor (Y page 82). 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 72). The anti-theft alarm system is
triggered if the door is opened from the
inside. Switch off the alarm (Y page 80).
The anti-theft alarm system is triggered if the door is opened from the inside. Switch off the alarm (Y page 80).
When a locked door is opened from inside the vehicle, the previous unlocking process will
be observed if the vehicle has been:
R locked with the locking button for the cen-
tral locking or
R locked automatically
The vehicle will be fully unlocked if it had pre- viously been fully unlocked. Only the door
which has been opened from the inside is
unlocked if only the driver's door had been
previously unlocked. Automatic locking feature
X
To deactivate: press and hold button :
for about five seconds until a tone sounds.
X To activate: press and hold button ;for
about five seconds until a tone sounds.
i If you press one of the two buttons and do
not hear a tone, the relevant setting has
already been selected. The vehicle is locked automatically when the
ignition is switched on and the wheels are
turning.
You could therefore be locked out if:
R the vehicle is being pushed.
R the vehicle is being towed.
R the vehicle is being tested on a dynamom-
eter.
You can also activate and deactivate the auto- matic locking function using the on-board
computer (Y page 247). Unlocking the driver's door (emer-
gency key element)
If the vehicle can no longer be locked or
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, the anti-
theft alarm system will be triggered
(Y page 80).
X Take the emergency key element out of the
key (Y page 89).
X Insert the emergency key element into the
lock of the driver's door as far as it will go. X
Turn the emergency key element anti-
clockwise as far as it will go to position 1.
The door is unlocked.
i On right-hand-drive vehicles, turn the
emergency key element clockwise. Doors
95Opening and closing Z