light MERCEDES-BENZ B-CLASS HATCHBACK 2015 Service Manual

Key functions
:
& Locks the vehicle
; % Unlocks the vehicle
X To unlock centrally: press the%button.
If you do not open the vehicle within approx-
imately 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 charge socket 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 audible
signal can be activated or deactivated using the
on-board computer (Y page 187).KEYLESS-GO
General notes Bear in mind that the drive system can be star-
ted 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 KEYLESS-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 han- dle is used must both be closed. The key must beoutside the vehicle. When locking or unlocking
with KEYLESS-GO, the distance between the keyand 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 vehicle. This occurs, for example:
R when starting the drive system
R whilst driving
R when the external door handles are touched
R during convenience closing X
To unlock the vehicle: touch the inner sur-
face of the door handle.
X To lock the vehicle: touch sensor surface :
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 extended
period.
For further information on the convenience
closing feature (Y page 83).72
KeyOpening and closing

X
To unlock the tailgate: pull tailgate han-
dle :.
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 or 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 flashes
twice briefly and lights up once, then KEY-
LESS-GO is deactivated (Y page 74).
X To activate: press any button on the key.
or X Insert the key into the ignition lock.
KEYLESS-GO and all of its associated features
are available again. KEYLESS-GO start function
General notes Bear in mind that the drive system can be star-
ted 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 sys-
tem. This means that only the driver's door and
the charge socket flap are unlocked when the
vehicle is unlocked. This is useful if you fre-
quently travel alone.
X To change the setting: press and hold down
the % and& buttons simultaneously
for about six seconds until the battery indica-
tor lamp (Y page 74) flashes twice.
If the setting of the locking system is changed
within the signal range of the vehicle, pressing
the & or% button:
R locks or
R unlocks the vehicle
The key now functions as follows:
X To unlock: press the%button once.
X To unlock centrally: press the%button
twice.
X To lock centrally: press the&button.
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 surface
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 simul-
taneously for approximately six seconds until
the battery check lamp flashes twice
(Y page 74). Emergency key element
General notes If the vehicle can no longer be unlocked with the
key or KEYLESS-GO, use the emergency key ele-
ment.
If you use the emergency key element to unlock
and open the driver's door or the tailgate, the
anti-theft alarm system will be triggered
(Y page 68). Key
73Opening and closing Z

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

The battery is discharged if battery check
lamp :does not light up briefly.
X Replace the battery (Y page 75).
i If the key battery is checked within the sig-
nal reception range of the vehicle, pressing
the & or% button:
R locks or
R unlocks the vehicle
i You can obtain a battery from any qualified
specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X Take the emergency key element out of the
key (Y page 73). X
Press emergency key element ;into the
opening in the key in the direction of the arrow
until battery tray cover :opens. When doing
so, do not hold cover :shut.
X Remove battery tray cover :.X
Repeatedly tap the key against your palm until
battery =falls out.
X Insert the new battery with the positive ter-
minal facing upwards. Use a lint-free cloth to
do so. X
Make sure that the surface of the battery is
free of lint, grease and other contamination.
X Insert the front tabs of battery tray cover :
and then press to close it.
X Insert emergency key element into the key
(Y page 74).
X Check the function of all key buttons on the
vehicle. Key
75Opening and closing Z

Problem
Possible causes/consequences and
M
MSolutions There is a fault with KEYLESS-GO.
X Lock/unlock the vehicle using the remote control function of the
key.
X Have the vehicle and key checked at a qualified specialist work-
shop.
If the vehicle can also not be locked/unlocked using the remote con-
trol function:
X Lock (Y page 80) or unlock (Y page 80) the vehicle using the
emergency key element.
X Have the vehicle and key checked at a qualified specialist work-
shop. The drive system 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 drive system again.
If this does not work: X Check the 12 V battery and charge it if necessary (Y page 256).
or
X Check the high-voltage battery and charge it if necessary
(Y page 135).
or
X Jump-start the vehicle (Y page 258).
or
X Consult a qualified specialist workshop. The drive system cannot
be started using the
Start/Stop button. The
key is in the vehicle. The vehicle is locked.
X Unlock the vehicle and try to start the vehicle again. The key battery is discharged or nearly discharged.
X Check the key battery (Y page 74) and replace it if necessary
(Y page 75).
If this does not work: X Start your vehicle with the key in the ignition lock. There is interference from a powerful source of radio waves.
X Start your vehicle with the key in the ignition lock. 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. Key
77Opening and closing Z

If the tailgate can no longer be unlocked:
R using the key, or
R using the remote operating switch in the door
control panel:
Use the emergency release on the inside of the tailgate.
You can reach the emergency release via the
luggage compartment.
Opening X
Remove the luggage compartment cover
(Y page 230).
X Fold rear seat backrest forwards
(Y page 228).
X Take the emergency key element out of the
key (Y page 73).
X Insert emergency key element ;into open-
ing :in the trim and push it in.
X Open the tailgate.
X Insert the emergency key element into the
key (Y page 74). Side windows
Important safety notes
G
WARNING
While opening the side windows, body parts
could become trapped between the side win- dow and the door frame as the side window
moves. There is a risk of injury.
Make sure that nobody touches the side win-
dow during the opening procedure. If some-
body becomes trapped, release the switch or pull the switch to close the side window again. G
WARNING
While closing the side windows, body parts in the closing area could become trapped. There is a risk of injury.
When closing make sure that no parts of the
body are in the closing area. If somebody
becomes trapped, release the switch or press
the switch to open the side window again. G
WARNING
If children operate the side windows they
could become trapped, particularly if they are left unsupervised. There is a risk of injury.
Activate the override feature for the rear side
windows. When leaving the vehicle, always
take the key with you and lock the vehicle.
Never leave children unattended in the vehi-
cle. Side window reversing feature
The side windows are equipped with an auto-
matic reversing feature. If a solid object blocks
or restricts a side window from travelling
upwards during the automatic closing process,
the side window opens again automatically. Dur-
ing the manual closing process, the side window
only opens again automatically after the corre-
sponding switch is released. The automatic
reversing feature is only an aid and is no substi- tute for your attention when closing a side win-
dow. G
WARNING
The reversing function does not react:
R to soft, light and thin objects, e.g. small fin-
gers
R while resetting
This means that the reversing feature cannot
prevent someone being trapped in these sit-
uations. There is a risk of injury.
When closing, make sure that no parts of the
body are in the closing area. If someone
becomes trapped, press the switch to open
the side window again. 82
Side windowsOpening and closing

AMG Exclusive Package:
when you lock the
vehicle, you can close the side windows at the
same time.
i Notes on the reversing feature for the side
windows (Y page 82).
Using the key X
Vehicles with Exclusive Package or AMG
Exclusive Package but without KEYLESS-
GO and the KEYLESS-GO start function: for
the following operations, point the tip of the
key at the door handle on the driver's door.
The key must be close to the driver's door
handle.
i Vehicles with KEYLESS-GO or the KEY-
LESS-GO start function: the key must be in
close proximity to the vehicle.
X Press and hold the &button until the side
windows are fully closed.
X To interrupt convenience closing: release
the & button.
Using KEYLESS-GO The driver's door and the door at which the han-
dle is used must both be closed. The key must beoutside the vehicle. The gap between the key
and the corresponding door handle should not
be greater than 1 m. X
Touch recessed sensor surface :on the
door handle until the side windows are fully
closed.
i Make sure you only touch recessed sensor
surface :.
X Make sure that all the side windows are
closed. X
To interrupt convenience closing: release
recessed sensor surface :on the door han-
dle. Resetting the side windows
If a side window can no longer be closed fully,
you must reset it.
X Close all doors.
X Turn the key to position 1or 2in the ignition
lock (Y page 126).
X Pull the corresponding switch on the door
control panel until the side window is com-
pletely closed (Y page 83).
X Hold the switch for an additional second.
If the side window opens again slightly:
X Immediately pull the corresponding switch on
the door control panel until the side window is completely closed (Y page 83).
X Hold the switch for an additional second.
X If the corresponding side window remains
closed after the button has been released, the
side window has been reset correctly. If this is not the case, repeat the steps above again. 84
Side windowsOpening and closing

Problems with the side windows
G
WARNING
If you close a side window again immediately after it has been blocked or reset, the side window
closes with increased or maximum force. The reversing function is then not active. Parts of the
body could be trapped in the closing area in the process. This poses an increased risk of injury or even fatal injury.
Make sure that no parts of the body are in the closing area. To stop the closing process, releasethe switch or push the switch again to reopen the side window. Problem
Possible causes/consequences and
M MSolutions A side window cannot be
closed because it is
blocked by objects, e.g.
leaves in the window
guide. X
Remove the objects.
X Close the side window. A side window cannot be
closed and you cannot
see the cause. If a side window is obstructed during closing and reopens again
slightly:
X Immediately after the window blocks, pull the corresponding switch
again until the side window has closed.
The side window is closed with increased force.
If a side window is obstructed again during closing and reopens again slightly:
X Immediately after the window blocks, pull the corresponding switch
again until the side window has closed.
The side window is closed without the anti-entrapment feature. Side windows
85Opening and closing 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). Correct driver's seat position
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. X
Observe the safety notes on seat adjustment
(Y page 87).
X Make sure that seat =is correctly adjusted.
Manual seat adjustment (Y page 88)Electrical seat adjustment (Y
page 88)
When adjusting the seat, make sure that:
R you are as far away from the driver's airbag
as possible
R you are sitting in a normal upright position
R you can fasten the seat belt properly
R you have moved the backrest to an almost
vertical position
R you have set the seat angle so that your
thighs are gently supported
R you can depress the pedals properly
X Check whether the head restraint is adjusted
correctly (Y page 89).
When doing so, make sure that you have
adjusted the head restraint so that the back of
your head is supported at eye level by the
centre of the head restraint.
X Observe the safety notes on steering column
adjustment (Y page 92).
X Make sure that steering wheel :is adjusted
correctly.
Adjusts the steering wheel (Y page 92)
When adjusting the steering wheel, make
sure that:
R you can hold the steering wheel with your
arms slightly bent
R you can move your legs freely
R you can see all the displays in the instru-
ment cluster clearly
X Observe the safety guidelines for seat belts
(Y page 36).
X Check whether you have fastened seat
belt ;properly (Y page 37).
The seat belt should:
R fit snugly across your body
R be routed across the middle of your shoul-
der
R be routed across your hips in the pelvic
area
X Before starting off, adjust the rear-view mirror
and the exterior mirrors (Y page 93) so that
you have a good view of road and traffic con-
ditions.
X Vehicles with a memory function: save the
seat and exterior mirror settings
(Y page 96). 86
Correct driver's seat positionSeats, steering wheel and mirrors

X
To raise: pull the head restraint up to the
desired height.
X To lower: press release catch :and push
the head restraint down until it is in the
desired position.
Removing and fitting the rear seat head
restraints X
Fold the seat backrest slightly forwards in
order to remove the head restraint
(Y page 228).
X To remove: pull the head restraint up to the
stop.
X Press release catch :and pull the head
restraint out of the guides.
X To refit: insert the head restraint so that the
notches on the bar are on the left when
viewed in the direction of travel.
X Push the head restraint down until you hear it
engage in position. Adjusting the 4-way lumbar support
You can adjust the contour of the front seat
backrests individually to provide optimum sup-
port for your back. :
Raises the backrest contour
; Softens the backrest contour
= Lowers the backrest contour
? Hardens the backrest contour Switching the seat heating on/off
Switching on/off G
WARNING
If you repeatedly switch on seat heating, the
seat cushion and backrest padding may
become very hot. The health of vehicle occu-
pants with limited temperature sensitivity or a limited ability to react to excessively high
temperatures may be affected or they may
even suffer burn-like injuries. There is a risk of
injury.
Therefore, do not switch on the seat heating
repeatedly. The three red indicator lamps in the button indi-
cate the heating level you have selected.
The system automatically switches down from
level 3to level 2after approximately eight
minutes. 90
SeatsSeats, steering
wheel and mirrors