change key battery MERCEDES-BENZ B-CLASS SPORTS 2015 Owners Manual

Deactivating and activating
If you do not intend to use the vehicle for a
longer period of time, you can deactivate KEY-
LESS-GO. The SmartKey will then use very lit- tle power, thereby conserving battery power.
For the purposes of activation/deactivation,
the vehicle must not be nearby. X To deactivate: press the&button on
the SmartKey twice in rapid succession.
The battery check lamp of the SmartKey( Y page 73) lights up twice briefly and
KEYLESS-GO is deactivated.
X To activate: press any button on the
SmartKey or insert the SmartKey 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
SmartKey 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 doorand the fuel filler flap are unlocked when the
vehicle is unlocked. This is useful if you fre-
quently travel on your own.
X To change the setting: simultaneously
press the %and& buttons for
approximately 6 seconds until the battery
check lamp ( Ypage 73) flashes twice.
iIf 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 SmartKey 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.
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 73).
Mechanical key
General notes
If the vehicle can no longer be locked or
unlocked with the SmartKey or KEYLESS-GO, use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door or the trunk lid, the
anti-theft alarm system will be triggered( Y page 67).
There are several ways to turn off the alarm:
X To turn the alarm off with the SmartKey:
press the %or& button on the
SmartKey.
or X Insert the SmartKey into the ignition lock.
or
X To deactivate the alarm with KEYLESS- GO: press the Start/Stop button in the igni-
72SmartKey
Opening and closing

tion lock. The SmartKey must be in the
vehicle.
or
X Lock or unlock the vehicle using KEYLESS-
GO. The SmartKey must be outside the
vehicle.
If you unlock the vehicle using the mechanical key, the fuel filler flap will not be unlocked
automatically. X To unlock the fuel filler flap: insert the
SmartKey into the ignition lock.
Removing the mechanical key
X Push release catch :in the direction of
the arrow and at the same time remove
mechanical key ;from the SmartKey.
For further information about:
R unlocking the driver's door ( Ypage 78)
R unlocking the cargo compartment(Y page 80)
R locking the vehicle ( Ypage 79)
Inserting the mechanical key
X
Push mechanical key ;completely into
the SmartKey until it engages and release
catch :is back in its basic position.
SmartKey battery
Important safety notes
GWARNING
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.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National
guidelines must be observed during disposal.
In California, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm .
Mercedes-Benz recommends that you have
the battery replaced at a qualified specialist
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 ( Ypage 74).
SmartKey73
Opening and closing
Z

Problems with the seat heating
ProblemPossible causes/consequences andMSolutions
The seat heating has
switched off prema-
turely or cannot be
switched on.The on-board voltage is too low because too many electrical con-
sumers are switched on.
X Switch off electrical consumers that you do not need, such as
the rear window defroster or interior lighting.
Once the battery is sufficiently charged, the seat heating will
switch back on automatically.
Steering wheel
Important safety notes
GWARNING
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 engine.
GWARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk ofinjury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Neverleave children unsupervised in the vehicle.
Adjusting the steering wheel
GWARNING
If the steering wheel is unlocked while the
vehicle is in motion, it could change position
unexpectedly. This could cause you to lose
control of the vehicle. There is a risk of anaccident.
Before starting off, make sure the steering
wheel is locked. Never unlock the steering
wheel while the vehicle is in motion.
:Release lever
;To adjust the steering wheel height
=To adjust the steering wheel position
(fore-and-aft adjustment)
X Push release lever :down completely.
The steering column is unlocked.
X Adjust the steering wheel to the desiredposition.
X Push release lever :up completely.
The steering column is locked.
X Check if the steering column is locked.
When doing so, try to push the steering
wheel up or down or try to move it in the
fore-and-aft direction.
Steering wheel97
Seats, steering wheel and mirrors
Z

Control panel in the grab handle in the
rear compartment
:To switch the reading lamp on/off
Interior lighting control
General notes
In order to prevent the vehicle's battery from discharging, the interior lighting functions are
automatically deactivated after some time
unless the SmartKey is in position 2in the
ignition lock.
The color and brightness for the ambient
lighting may be set using COMAND or Audio
20 (see the separate operating instructions).
Automatic interior lighting control
X To switch on: set the switch to center
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 SmartKey from the ignition
lock.
The interior light is activated for a short while when the SmartKey is removed from the igni-
tion lock. This delayed switch-off can be
adjusted using COMAND or Audio 20 (see the separate Operator's Manual).
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 or (if the
door is closed) to the center 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
SmartKey.
Replacing bulbs
Important safety notes
GWARNING
Bulbs, lamps and connectors can get very hotwhen operating. If you change a bulb, you
could burn yourself on these components.
There is a risk of injury.
Allow these components to cool down beforechanging a bulb.
Do not use a bulb that has been dropped or if
its glass tube has been scratched.
The bulb may explode if: R you touch it
R it is hot
R you drop it
R you scratch it
Only operate bulbs in enclosed lamps
designed for that purpose. Only install spare
Replacing bulbs109
Lights and windshield wipers
Z

SmartKey
Display messagesPossible causes/consequences andMSolutions
Â
Key Does Not
Belong to Vehicle
You have put the wrong SmartKey in the ignition lock.
X Use the correct SmartKey.
Â
TakeYourKeyfrom
Ignition
The SmartKey is in the ignition lock.
X Remove the SmartKey.
Â
Obtain a New Key
The SmartKey needs to be replaced.
X Visit a qualified specialist workshop.
Â
ReplaceKeyBattery
The SmartKey battery is discharged.
X Change the battery ( Ypage 74).
Â
Don't Forget Your
Key
The display message is shown for a maximum of 60 seconds and
is only a reminder.
You have opened the driver's door with the engine switched off.
The SmartKey is not in the ignition lock.
X Take the SmartKey with you when you leave the vehicle.
Â
Key Not Detected
(red display message)
The SmartKey is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Ypage 152).
X Locate the SmartKey.
Because there is interference from a strong source of radio waves,
the key is not detected whilst the engine 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 Secure the vehicle against rolling away ( Ypage 152).
X Insert the SmartKey into the ignition lock and bring into keymode.
234Display messages
On-board computer and displays

XDepress and hold the brake pedal.
X Shift the automatic transmission to posi-
tion N.
X Leave the SmartKey in position 2in the
ignition lock.
X Release the brake pedal.
X Release the electric parking brake.
X Switch on the hazard warning lamps(Y page 107).
iIn order to signal a change of direction
when towing the vehicle with the hazard
warning lamps switched on, use the com-
bination switch as usual. In this case, only
the indicator lamps for the direction of
travel flash. After resetting the combina-
tion switch, the hazard warning lamp starts
flashing again.
Transporting the vehicle
!
You may only secure the vehicle by the
wheels, not by parts of the vehicle such as
axle or steering components. Otherwise,
the vehicle could be damaged.
X Turn the SmartKey to position 2in the igni-
tion lock ( Ypage 135).
X Shift the transmission to position N.
As soon as the vehicle has been loaded: X Prevent the vehicle from rolling away by
applying the electric parking brake.
X Shift the transmission to position P.
X Turn the SmartKey to position 0in the igni-
tion lock and remove it.
X Secure the vehicle.
The towing eye can be used to pull the vehicle
onto a trailer or transporter for transporting
purposes.
Notes on 4MATIC vehicles
!
Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised,
as doing so will damage the transmission.
Vehicles with 4MATIC may only either be
towed away with both axles on the ground or be loaded up and transported.
If the vehicle's transmission, front, or rear
axle is damaged, have the vehicle transported on a truck or trailer.
In the event of damage to the electrical
system:
If the battery is defective, the automatic
transmission will be locked in position P. To
shift the automatic transmission to positionN , you must provide power to the vehicle's
electrical system in the same way as when
jump-starting ( Ypage 293).
Have the vehicle transported on a transporter
or trailer.
Tow-starting (emergency engine
starting)
!
Vehicles with automatic transmission
must not be tow-started. You could other-
wise damage the automatic transmission.
iYou can find information on "Jump-start-
ing" under ( Ypage 293).
Fuses
Important safety notes
GWARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher amper-
age, the electric cables could be overloaded.
This could result in a fire. There is a risk of an
accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
298Fuses
Roadside Assistance