2015 MERCEDES-BENZ B-CLASS HATCHBACK change key battery

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

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

Folding the exterior mirrors in/out elec-
trically X
Turn the key to position 1or 2in the ignition
lock (Y page 126).
X Briefly press button :.
Both exterior mirrors fold in or out.
i Make sure that the exterior mirrors are
always folded out fully while driving. They
could otherwise vibrate.
i If you are driving faster than 47 km/h, you
can no longer fold in the exterior mirrors.
Resetting the exterior mirrors If the battery has been disconnected or com-
pletely discharged, the exterior mirrors must be
reset. The exterior mirrors will otherwise not
fold in when you select the "Fold in mirrors whenlocking" function in the on-board computer
(Y page 188).
X Turn the key to position 1in the ignition lock
(Y page 126).
X Briefly press button :.
Folding the exterior mirrors in/out
automatically If the "Fold in mirrors when locking" function is
activated in the on-board computer
(Y page 188):
R the exterior mirrors fold in automatically as
soon as you lock the vehicle from the outside
R the exterior mirrors fold out again automati-
cally as soon as you unlock the vehicle and
then open the driver's or front-passenger
door
i If the exterior mirrors have been folded in
manually, they do not fold out. Exterior mirror pushed out of position If an exterior mirror has been pushed out of
position (forwards or backwards), proceed as
follows:
X Vehicles without electrically folding exte-
rior mirrors: manually move the exterior mir-
ror into the correct position.
X Vehicles with electrically folding exterior
mirrors: press and hold the mirror-folding
button (Y page 94) until you hear a click and
the mirror audibly engages into position.
The mirror housing is engaged again and you can adjust the exterior mirrors as usual
(Y page 93). Automatic anti-dazzle mirrors
G
WARNING
Electrolyte may escape if the glass of an auto- matic anti-dazzle mirror breaks. Electrolyte is
harmful and causes irritation. It must not
come into contact with your skin, eyes, res-
piratory organs or clothing or be swallowed.
There is a risk of injury.
If you come into contact with electrolyte,
observe the following:
R immediately rinse off electrolyte from your
skin with water.
R immediately and thoroughly rinse electro-
lyte out of eyes using clean water.
R if electrolyte is swallowed, immediately
rinse out your mouth thoroughly. Do not
induce vomiting.
R if electrolyte comes into contact with skin
or eyes or is swallowed, seek medical atten-
tion immediately.
R immediately change out of clothing that has
been in contact with electrolyte.
R if an allergic reaction occurs, seek medical
attention immediately.
The "Automatic anti-dazzle mirrors" function is
only available if the vehicle is equipped with the
"Mirror package". 94
MirrorsSeats, steering wheel and
mirrors

Display messages
Possible causes/consequences and
M
MSolutions Â
Change Change
key
keybatteries
batteries The key battery is discharged.
X Replace the battery (Y page 75).Â
Key not detected Key not detected
(red display message) The key is not in the vehicle.
A warning tone also sounds.
If the drive system is switched off, you can no longer lock the vehicle
centrally or start the drive system.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Safeguard the vehicle against rolling away (Y page 145).
X Locate the key. There is interference from a strong source of radio waves, and as a
result the key is not detected while the drive system is running.
A warning tone also sounds.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Safeguard the vehicle against rolling away (Y page 145).
X Insert the key into the ignition lock and bring into key mode. Â
Key not detected Key not detected
(white display message) The key is currently undetected.
X Change the location of the key in the vehicle.
If the key still cannot be detected:
X Operate the vehicle with the key in the ignition lock if necessary. Â
Remove Remove
starting
starting but‐
but‐
ton,
ton, then
theninsert
insert key
key The key is continually undetected.
KEYLESS-GO is temporarily malfunctioning or is defective. A warning
tone also sounds.
X Insert the key into the ignition lock and turn it to the desired posi-
tion.
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
General notes
Some systems perform a self test when the ignition is switched on. Some warning and indicator
lamps may temporarily switch on or flash during the test. This behaviour is nothing to be concerned about.
The warning and indicator lamps will alert you to a malfunction if they switch on or flash after the
drive system is started or while driving. Wa
rning and indi cator lamps in the instrument cluster
213On-board computer and displays Z

Removing the towing eye
X
Loosen the towing eye and unscrew it.
X Place the towing eye in the stowage well
under the luggage compartment floor
(Y page 249).
X Vehicles with a TIREFIT kit: replace the tyre
inflation compressor. Towing the vehicle with both axles on
the ground
It is important that you observe the safety
instructions when towing away your vehicle
(Y page 260).
X On vehicles with KEYLESS-GO or the KEY-
LESS-GO start function: you must use the
key instead of the Start/Stop button
(Y page 127).
The transmission automatically shifts to posi-
tion Pwhen you open the driver's or front-
passenger door or when you remove the key
from the ignition lock. In order to ensure that the transmission stays in position Nwhen towing
the vehicle, you must observe the following
points:
X Make sure that the vehicle is stationary.
X Turn the key to position 2in the ignition lock.
X Depress the brake pedal and keep it
depressed.
X Shift the transmission to position N.
X Release the brake pedal.
X Release the electric parking brake.
X Switch on the hazard warning lamps
(Y page 100).
X Leave the key in position 2in the ignition lock.
If the 12 V battery indicator lamp lights up, you
must observe the following points:
X Pull over and safely stop the vehicle as soon
as possible, paying attention to road and traf-
fic conditions.
X Shift the transmission to position P.
X Apply the electric parking brake.
i In order to signal a change of direction when
towing the vehicle with the hazard warning
lamps switched on, use the combination
switch as usual. In this case, only the turn
signals for the desired direction flash. When you reset the combination switch, the hazard
warning lamps start flashing again. Towing the vehicle with the front axle
raised
When towing your vehicle with the front axle
raised, it is important that you observe the
safety instructions (Y page 260).
! The ignition must be switched off if you are
towing the vehicle with the front axle raised.
Intervention by ESP ®
could otherwise dam-
age the brake system.
X On vehicles with KEYLESS-GO or the KEY-
LESS-GO start function: you must use the
key instead of the Start/Stop button
(Y page 127).
X Make sure that the vehicle is stationary.
X Turn the key to position 2in the ignition lock.
X When the vehicle is stationary, depress the
brake pedal and keep it depressed.
X Shift the transmission to position P.
X Release the brake pedal.
X Release the electric parking brake.
X Deactivate tow-away protection (Y page 68).
X Deactivate automatic locking (Y page 187).
X Switch on the hazard warning lamps
(Y page 100).
X Turn the key in the ignition lock to position 0
and leave the key in the ignition lock. Towing the vehicle away with the rear
axle raised
When towing your vehicle away with the rear
axle raised, it is important that you observe the safety instructions (Y page 260).
! The ignition must be switched off if you are
towing the vehicle with the rear axle raised.
Intervention by ESP ®
could otherwise dam-
age the brake system. 262
RecoveryBreakdown assistance