2012 MERCEDES-BENZ B-CLASS key battery

Automatic transmission
Automatic drive program ............... 144
Changing gear ............................... 143
DIRECT SELECT lever .....................140
Display message
............................ 220
Drive program display ....................141
Driving tips .................................... 143
Emergency running mode ..............147
Engaging drive position .................. 142
Engaging neutral ............................ 141
Engaging reverse gear ................... 141
Engaging the park position ............ 141
Holding the vehicle stationary on
uphill gradients .............................. 143
Kickdown ....................................... 143
Manual drive program ....................144
Overview ........................................ 140
Problem (malfunction) ...................147
Program selector button ................143
Pulling away ................................... 136
Starting the engine ........................ 135
Steering wheel paddle shifters ...... 144
Transmission position display ........ 141
Transmission positions .................. 142
Automatic transmission
emergency mode ............................... 147B
Backup lamp Changing bulbs .............................. 109
Display message ............................ 211
Bag hook

............................................ 243
BAS (Brake Assist System) ................. 59
Battery (SmartKey) Checking .......................................... 70
Important safety notes .................... 70
Replacing ......................................... 70
Battery (vehicle)
Charging ........................................ 288
Display message ............................ 213
Important safety notes .................. 285
Jump starting ................................. 289
Belt force limiter
Activation ......................................... 49
Function ........................................... 49
Blinds
see Roller sunblind Blind Spot Assist
Activating/deactivating .................195
Display message

............................ 216
Notes/function .............................. 181
Brake Assist
see BAS (Brake Assist System)
Brake fluid
Display message ............................ 207
Notes ............................................. 332
Brake lamps
Adaptive ........................................... 62
Changing bulbs .............................. 109
Display message ............................ 209
Brakes
ABS .................................................. 59
Adaptive Brake Assist ......................61
BAS .................................................. 59
Brake fluid (notes) .........................332
Display message ............................ 201
Driving tips .................................... 154
Important safety notes .................. 154
Maintenance .................................. 155
Parking brake ................................ 150
Warning lamp ................................. 225
Breakdown
see Flat tire
see Towing away/tow-starting
Bulbs
see Changing bulbs C
Calling up a malfunction see Display messages


Car
see Vehicle
Care
Carpets .......................................... 277
Car wash ........................................ 271
Display ........................................... 275
Exhaust pipe .................................. 275
Exterior lights ................................ 274
Gear or selector lever ....................276
Interior ........................................... 275
Matte finish ................................... 273
Notes ............................................. 271
Paint .............................................. 273
Plastic trim .................................... 276 Index
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(vehicles without the EASY-
VARIO-PLUS system)
.....................240
Folding the backrest (rear
compartment) forwards/back
(vehicles with the EASY-VARIO-
PLUS system) ................................ 241
Seat belts
Adjusting the height ......................... 48
Belt force limiters ............................ 49
center rear-compartment seat
.........48
Cleaning ......................................... 277
Correct usage .................................. 46
Emergency Tensioning Devices ........ 49
Fastening ......................................... 47
Important safety guidelines .............45
Releasing ......................................... 48
Safety guidelines ............................. 40
Warning lamp ................................. 224
Warning lamp (function) ................... 49
Seats
Adjusting (electrically) .....................88
Adjusting (manually) ........................ 88
Adjusting the 4-way lumbar
support ............................................ 90
Adjusting the head restraint ............ 89
Cleaning the cover ......................... 276
Correct driver's seat position ........... 86
Important safety notes .................... 87
Seat heating problem ...................... 91
Storing settings (memory function) .. 95
Switching seat heating on/off ......... 91
Sensors (cleaning instructions) .......275
Service menu (on-board computer) . 196
Service products Brake fluid ..................................... 332
Coolant (engine) ............................ 333
Engine oil ....................................... 332
Fuel ................................................ 330
Important safety notes .................. 329
Refrigerant (air-conditioning
system) .......................................... 334
Washer fluid ................................... 334
Service work
see ASSYST PLUS
Settings
Factory (on-board computer) ......... 199
On-board computer ....................... 196
Setting the air distribution ...............126Setting the airflow
............................ 126
Side impact air bag ............................. 44
Side marker lamp (display
message) ............................................ 211
Side windows Cleaning ......................................... 274
Convenience closing feature ............ 78
Convenience opening feature
..........78
Important safety information ........... 77
Opening/closing .............................. 77
Problem (malfunction) .....................79
Resetting ......................................... 79
Sliding sunroof
see Panorama roof with power
tilt/sliding panel
SmartKey
Changing the battery ....................... 70
Changing the programming ............. 69
Checking the battery ....................... 70
Convenience closing feature ............ 78
Convenience opening feature .......... 78
Display message ............................ 223
Door central locking/unlocking ....... 68
Important safety notes .................... 68
Loss ................................................. 72
Mechanical key ................................ 69
Positions (ignition lock) ................. 135
Problem (malfunction) .....................72
Starting the engine ........................ 135
SmartKey positions (ignition lock) ..135
Snow chains ...................................... 301
Sockets Center console .............................. 251
Luggage compartment ................... 251
Points to observe before use ......... 250
Rear compartment ......................... 251
Specialist workshop ............................ 24
Speed, controlling see Cruise control
Speedometer
Activating/deactivating the
additional speedometer .................196
Digital ............................................ 190
In the Instrument cluster ................. 29
Segments ...................................... 187
Selecting the unit of measurement 196
see Instrument cluster Index
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Characteristics when ESP
®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ ESP®
warning lamp in
the instrument cluster flashes. In such
situations, ESP ®
will not stabilize the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability.
R the engine's torque is no longer limited and
the drive wheels are able to spin. The
spinning of the wheels results in a cutting
action, which provides better grip.
R ETS is still active.
R ESP ®
still provides support when you
brake. EBD (electronic brake force
distribution)
i Observe the "Important safety notes"
section for driving safety systems
(Y page 59). G
WARNING
If EBD has malfunctioned, the rear wheels can
still lock, e.g. under full braking. This
increases the risk

of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have
the brake system checked at a qualified
specialist workshop.
Observe information regarding indicator and
warning lamps ( Y page 225) as well as
display messages ( Y page 203).
EBD monitors and controls the brake
pressure on the rear wheels to improve
driving stability while braking. ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and offers increased braking comfort. In
addition to the braking function, ADAPTIVE
BRAKE also has the HOLD function
(Y page 168) and hill start assist (Y page 136). For further information, see
Driving tips (Y page 154).
STEER CONTROL
STEER CONTROL helps

you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilization.
This steering assistance is provided in
particular if:
R both right wheels or both left wheels are on
a wet or slippery road surface when you
brake
R the vehicle starts to skid
If ESP ®
is malfunctioning, you will not receive
steering support from STEER CONTROL.
Power steering will, however, continue to
function. Theft deterrent locking system
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
X To activate: remove the SmartKey from
the ignition lock.
X To deactivate: switch on the ignition.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. The
engine can be started by anyone with a valid
SmartKey that is left inside the vehicle.
i The immobilizer is always deactivated
when you start the engine.
In the event that the engine cannot be
started when the starter battery is fully
charged, the immobilizer may be faulty.
Contact an authorized Mercedes-Benz
Center or call

1-800-FOR-MERCedes (in the
USA) or 1-800-387-0100 (in Canada). 64
Theft deterrent locking system
Safety
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X
To lock centrally: press button :.
The SmartKey centrally locks/unlocks:
R the doors
R the tailgate
R the fuel filler flap
The turn signals flash once when unlocking
and three times when locking.
i When it is
dark, the surround lighting also
comes on if it is activated in the on-board
computer (Y page 198).
i You can also set an audible signal to
confirm that the vehicle has been locked.
The audible signal can be activated and
deactivated using the on-board computer
(Y page 199). Changing the settings of the locking
system
You can change the settings of the locking
system. When you then unlock the vehicle
only the driver's door and the fuel filler flap
are unlocked. This is useful if you frequently
travel on your own.
X To change the setting: press and hold
down the % and & buttons
simultaneously for approximately six
seconds until the battery check lamp
(Y page 70) flashes twice.
i 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 SmartKey now functions as follows:
X To unlock the driver's door: press the
% button once.
X To unlock centrally: press the %
button twice.
X To lock centrally: press the & button.
X To restore the factory settings: press
and hold down

the % and & buttons simultaneously for approximately six
seconds until the battery check lamp
flashes twice (
Y page 70). Mechanical key
General notes If the vehicle can no longer be unlocked with
the SmartKey, use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm
system will be triggered (
Y page 65).
There are several ways to turn off the alarm:
X Press the

% or & button on the
SmartKey.
or
X Insert the SmartKey into the ignition lock.
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. SmartKey
69
Opening and closing Z
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SmartKey battery
Important safety notes G
WARNING
Batteries contain toxic and corrosive
substances. 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 batteries 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 ( Y page 70). i
If the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the &

or % button:
R locks or
R unlocks the vehicle
i You can get a battery at any qualified
specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X
Take the mechanical key out of the
SmartKey (Y page 69). X
Press mechanical key ; into the opening
in the SmartKey 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 SmartKey against your
palm until battery = falls out.
X Insert the new battery with the positive
terminal facing upwards. Use a lint-free
cloth to do so.70
SmartKey
Opening and closing
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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 mechanical key into the
SmartKey.
X Check the function of all SmartKey buttons
on the vehicle. SmartKey
71
Opening and closing Z
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Problems with the SmartKey
Problem Possible causes/consequences and
M SolutionsYou cannot lock or
unlock the vehicle
using the SmartKey. The SmartKey battery is discharged or nearly discharged.
X
Try again to lock/unlock the vehicle using the remote control
function of the SmartKey. Point the tip of the SmartKey at the
driver's door handle from close range and press the % or
& button.
If this does not work:
X Check the SmartKey battery and replace it if necessary
(Y page 70).
X Unlock ( Y page 75) or lock ( Y page 75) the vehicle using the
mechanical key. There is interference from a powerful source of radio waves.
X
Try again to lock/unlock the vehicle using the remote control
function of the SmartKey. Point the tip of the SmartKey at the
driver's door handle from close range and press the % /
& button. The SmartKey is faulty.
X
Unlock ( Y page 75) or lock ( Y page 75) the vehicle using the
mechanical key.
X Have the SmartKey checked at a qualified specialist workshop. You have lost a
SmartKey. X
Have the SmartKey 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
mechanical key. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well.72
SmartKeyOpening and closing
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Problem Possible causes/consequences and
M SolutionsThe engine cannot be
started using the
SmartKey. 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 285).
or
X Jump-start the vehicle (Y page 289).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the
SmartKey. The steering lock is mechanically blocked.
X
Remove the SmartKey and reinsert it into the ignition lock. While
doing this, turn the steering wheel in both directions. Doors
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shift the automatic transmission out of
parking position P.
R starting the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you
and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. G
WARNING
If persons, particularly children are subjected
to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle. Unlocking and opening doors from
the inside
X
To unlock a front door: pull door
handle ;.
Locking knob : pops up.
The door is unlocked and can be opened. Doors
73
Opening and closing Z
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