2011 MERCEDES-BENZ B-CLASS HATCHBACK change key battery

Changing the settings of the locking
system
X To change the setting: press and hold
down the %and& buttons simulta-
neously for approximately six seconds until
the battery check lamp flashes twice
(Y page 74).
i If the setting of the locking system is
changed within the signal range of the vehi-
cle, pressing the &or% buttonlocks
or 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.
You can change the setting of the locking
system in such a way that only the driver's
door and the fuel filler flap are unlocked. This
is useful if you frequently travel on your own. Restoring factory settings
X Press the %and& buttons simulta-
neously for approximately six seconds until
the battery check lamp flashes twice. Emergency key element
General notes If the vehicle can no longer be unlocked with
the key, use the emergency key element.
If you use the emergenc ykey element to
unlock and open the driver's door, the anti-
thef talarm system will be triggered
(Y page 68).
There are several ways to tur noff the alarm:
X Press the %or& button on the key.
or
X Insert the key into the ignition lock. 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. Battery of the key
Important safety notes G
WARNING
Batteries are toxic and contain caustic sub-
stances. For this reason, keep batteries out of
the reach of children.
If a battery has been swallowed, visi tadoctor
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 an
environmentally responsible
recycling system.
Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe- Key
73Opening and closing
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cialist workshop or to a col-
lection point for used batter-
ies.
Have the batteries changed at a qualified spe-
cialist workshop.
Checking the battery X
Press the &or% button.
The battery is working properly if battery
check lamp :lights up briefly.
The battery is discharged if battery check
lamp :does not light up briefly.
X Change the battery (Y page 74).
i If the key battery is checked within the
signal receptio nrange of the vehicle, press-
ing the &or% button:
R locks or
R unlocks the vehicle
i You can get a battery in any qualified spe-
cialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X
Take the emergency key elemen tout 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 no thold 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 from lint, grease and all other forms of
contamination.
X Insert the front tabs of battery tray
cover :and then press to close it.
X Insert the emergency key element into the
key.
X Check the function of all key buttons on the
vehicle. 74
KeyOpening and closing

Problems with the key
Problem Possible causes/consequences and
M Solutions
You cannot lock or
unlock the vehicle
using the key. The key battery is discharged or nearly discharged.
X
Try again to lock/unlock the vehicle using the remote control
function of the key. Point the tip of the key at the driver's door
handle from close range and press the %/& button.
If this does not work:
X Check the key battery and replace it if necessary (Y page 74).
X Lock (Y page 77) or unlock (Y page 78) the vehicle using
the emergency key element. The key is faulty.
X
Lock (Y page 77) or unlock (Y page 78) the vehicle using
the emergency key element.
X Have the key checked at a qualified specialist workshop. 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. The engine 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 engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 280).
or
X Jump-start the vehicle (Y page 283).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the key. The steering lock is mechanically blocked.
X
Remove the key and reinsert it into the ignition lock. While doing
this, turn the steering wheel in both directions. Key
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Interior lighting control
Important notes In order to preven
tthe vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time
except for when the key is in position 2in the
ignition lock.
Automatic interior lighting control X
To switch on: set the switch to centre
position B.
X To switch off: set the switch to the |
position.
The interior lighting automatically switches
on if you:
R unlock the vehicle
R open a door
R remove the key from the ignition lock
The interior lighting is activated for a short
time when the key is removed from the igni-
tion lock. You can activate this delayed
switch-off using the on-board computer
(Y page 202).
Manual interior lighting control X
To switch the front interior lighting on:
set the switch to the cposition.
X To switch the front interior lighting off:
set the switch to the |position.
X To switch the rear interior lighting on/
off: press the ubutton.
X To switch the reading lamps on/off:
press the pbutton. Crash-responsive emergency lighting
The interior lighting is activated automatically
if the vehicle is involved in an accident. X
To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or
X Lock and then unlock the vehicle using the
key. Replacing bulbs
Important safety notes
Xenon bulbs G
DANGER
Xenon bulbs are under high voltage. If you
touch the electrical contacts of a xenon bulb,
you could suffer an electric shock and be seri-
ously or even fatally injured. For this reason,
do not remove the cover of xenon bulbs.
Do not change the xenon bulbs yourself, but
have them replaced at a qualified workshop.
If your vehicle is equipped with xenon bulbs,
you can recognise this by the following: the
cone of light from the xenon bulbs moves
from the top to the bottom and back again
when you start the engine. For this to be
observed, the lights must be switched on
before starting the engine.
Bulbs and lamps are an important aspect of
vehicle safety. You must therefore make sure
that these function correctly at all times.
Have the headlamp setting checked regularly.
Other bulbs G
WARNING
Bulbs and lamps can be very hot. You should
therefore allow them to cool down before you
change them. Otherwise, you could be burned
if you touch them.
Keep bulbs out of the reach of children. Oth-
erwise, they could damage the bulbs, for
example, and injure themselves. Replacing bulbs
103Lights and windscreen wipers
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