2012 MERCEDES-BENZ CLS key battery

If you pull on the handle of the trunk lid, only
the trunk of the vehicle is unlocked.
Changing the settings of the locking
system
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.
XTo change the setting: press and hold
down the % and & buttons
simultaneously for approximately six
seconds until the battery check lamp
( Y page 76) flashes twice.
i
If the setting of the locking system is
changed within the signal range of the
vehicle, pressing the & or % button
locks or unlocks the vehicle.
The SmartKey now functions as follows:
XTo unlock the driver's door: press the
% button once.XTo unlock centrally: press the %
button twice.XTo lock centrally: press the & button.
The KEYLESS-GO function is changed as
follows:
XTo unlock the driver's door: touch the
inner surface of the door handle on the
driver's door.XTo unlock centrally: touch the inner
surface of the door handle on the front-
passenger door or the rear door.XTo lock centrally: touch the outer sensor
surface on one of the door handles.
Restoring the factory settings
XPress the % and & buttons
simultaneously for approximately six
seconds until the battery check lamp
flashes twice.Mechanical key
General notes
If the vehicle can no longer be locked or
unlocked with the SmartKey, 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 69).
There are several ways to turn off the alarm:
XTo turn the alarm off with the
SmartKey: press the % or & button
on the SmartKey.
or
XInsert the SmartKey into the ignition lock.
or
XTo deactivate the alarm with KEYLESS-
GO: press the Start/Stop button in the
ignition lock. The SmartKey must be in the
vehicle.
or
XLock 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.
XTo unlock the fuel filler flap: insert the
SmartKey in the ignition lock.
Removing the mechanical key
SmartKey75Opening/closingZ

XPush release catch : in the direction of
the arrow and at the same time, remove
mechanical key ; from the SmartKey.
SmartKey battery
Important safety notes
It is advisable to have batteries replaced at a
qualified specialist workshop, e.g. at an
authorized Mercedes-Benz Center.
GWARNING
Batteries contain toxic and caustic
substances. For this reason, keep batteries
out of the reach of children.
If a battery has been swallowed, seek medical
help immediately.
GWARNING
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. Observe
government disposal guidelines. California
residents, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm .
Checking the battery
XPress the & or % button.
The SmartKey battery is working properly if
battery check lamp : lights up briefly.
If battery check lamp : does not light up
briefly during the test, the SmartKey battery
is discharged.
XChanging the battery ( Y page 76)
i
The battery can be obtained from any
authorized Mercedes-Benz Center.
i If the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the & or % button locks or
unlocks the vehicle.
Changing the battery
You require a CR 2025 3 V cell battery.
XTake the mechanical key out of the
SmartKey ( Y page 75).XPress 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.XRemove battery tray cover :.XRepeatedly tap the SmartKey against your
palm until battery = falls out.XInsert the new battery with the positive
terminal facing upwards. Use a lint-free
cloth to do so.76SmartKeyOpening/closing

XMake sure that the surface of the battery is
free from lint, grease and all other forms of
contamination.XInsert the front tabs of battery tray
cover : and then press to close it.XInsert the mechanical key into the
SmartKey.XCheck the function of all SmartKey buttons
on the vehicle.SmartKey77Opening/closingZ

Problems with the SmartKeyProblemPossible causes/consequences and M SolutionsYou cannot lock or
unlock the vehicle
using the SmartKey.The SmartKey battery is discharged or nearly discharged.XTry 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.
If this does not work:
XCheck the SmartKey battery and replace it if necessary
( Y page 76).XLock ( Y page 81) or unlock ( Y page 81) the vehicle using
the mechanical key.The SmartKey is faulty.XLock ( Y page 81) or unlock ( Y page 81) the vehicle using
the mechanical key.XHave the SmartKey checked at a qualified specialist workshop.You can no longer lock
or unlock the vehicle
using KEYLESS-GO.There is interference from a powerful source of radio waves.XLock/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.There is a malfunction with KEYLESS-GO.XLock/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.XHave KEYLESS-GO checked at a qualified specialist workshop.
If this does not work:
XCheck the SmartKey battery and replace it if necessary
( Y page 76).XLock ( Y page 81) or unlock ( Y page 81) the vehicle using
the mechanical key.You have lost a
SmartKey.XHave the SmartKey canceled at an authorized Mercedes-Benz
Center.XReport the loss immediately to the vehicle insurers.XIf necessary, have the locks changed as well.You have lost the
mechanical key.XReport the loss immediately to the vehicle insurers.XIf necessary, have the locks changed as well.78SmartKeyOpening/closing

ProblemPossible causes/consequences and M SolutionsThe engine cannot be
started using the
SmartKey.The on-board voltage is too low.XSwitch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
XCheck the starter battery and charge it if necessary
( Y page 302).
or
XJump-start the vehicle ( Y page 305).
or
XConsult a qualified specialist workshop.The engine cannot be
started using KEYLESS-
GO. The SmartKey is in
the vehicle.A door is open. Therefore, the SmartKey cannot be detected as
easily.XClose the door and try to start the vehicle again.There is interference from a powerful source of radio waves.XStart your vehicle with the SmartKey in the ignition lock.Doors
Important safety notes
GWARNING
When leaving the vehicle, always remove the
SmartKey from the ignition lock. Always take
the SmartKey with you and lock the vehicle.
Do not leave children unsupervised in the
vehicle, even if they are secured in a child
restraint system, and do not give them access
to an unlocked vehicle. A child's unsupervised
access to a vehicle could result in an accident
and/or serious personal injury. They could:
R injure themselves on vehicle parts
R be seriously or fatally injured by extreme
heat or cold
R injure themselves or have an accident with
vehicle equipment that may still be in
operation even after the SmartKey has
been removed from the ignition, such as the
seat adjustment, steering wheel
adjustment or memory function.
If children open a door, they could cause
severe or even fatal injury to other persons; if
they get out of the vehicle, they could injure
themselves when doing so or be seriously or
even fatally injured by any passing traffic.
Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and a child could be burned on these
parts.GWARNING
Do not carry heavy or hard objects in the
passenger compartment or trunk unless they
are firmly secured in place.
Unsecured or improperly positioned cargo
increases a child's risk of injury in the event
of
R strong braking maneuvers
R sudden changes of direction
R an accident
Doors79Opening/closingZ

XInsert the mechanical key into the trunk lid
lock as far as the stop.XTurn the mechanical key clockwise from
position 1 to position 2.XRemove the mechanical key.XInsert the mechanical key into the
SmartKey.
Unlocking the trunk (mechanical key)
! The trunk lid swings upwards when
opened. Therefore, make sure that there is
sufficient clearance above the trunk lid.
If the trunk cannot be unlocked with the
SmartKey or KEYLESS-GO, use the
mechanical key.
If you use the mechanical key to unlock and
open the trunk lid, the anti-theft alarm system
will be triggered ( Y page 69).
XTake the mechanical key out of the
SmartKey ( Y page 75).XInsert the mechanical key into the trunk lid
lock as far as the stop.XTurn the mechanical key counter-clockwise
from position 1 as far as it will go to
position 2.
The trunk is unlocked.XTurn the mechanical key back to position
1 and remove it.XInsert the mechanical key into the
SmartKey.
Trunk emergency release
You can open the trunk lid from inside the
vehicle with the emergency release button.
XBriefly press emergency release
button :.
The trunk lid unlocks and opens.
The trunk lid can be unlocked and opened
with the trunk lid emergency release when
the vehicle is stationary or while driving.
Trunk lid emergency release light:
R emergency release button : flashes for
30 minutes after the trunk lid is opened.
R emergency release button : flashes for
60 minutes after the trunk lid is closed.
The trunk lid emergency release does not
open the trunk lid if the battery is
disconnected or discharged.
Trunk85Opening/closingZ

The system automatically switches down
from level 2 to level 1 after approximately ten
minutes.
The system automatically switches off
approximately 20 minutes after it is set to
level 1.XMake sure that the SmartKey is in position
2 in the ignition lock.XTo switch on: press button : repeatedly
until the desired heating level is set.XTo switch off: press button : repeatedly
until all the indicator lamps go out.
Problems with the seat heating
The seat heating has switched off
prematurely or cannot be switched on. The
vehicle's electrical system voltage is too low
because too many electrical consumers are
switched on.
XSwitch off electrical consumers which you
do not need, such as the rear window
defroster or interior lighting.
Switching the seat ventilation on/off
Switching on/off
The three blue indicator lamps in the buttons
indicate the ventilation level you have
selected.
i If the battery voltage is too low, the seat
ventilation may switch off.
XMake sure that the SmartKey is in position
2 in the ignition lock.XTo switch on: press button : repeatedly
until the desired ventilation level is set.
i You can open the side windows and the
sliding sunroof with the SmartKey
( Y page 87). The seat ventilation of the
driver's seat automatically switches to the
highest level.
XTo switch off: press button : repeatedly
until all the indicator lamps go out.
Problems with the seat ventilation
The seat ventilation has switched off
prematurely or cannot be switched on. The
vehicle's electrical system voltage is too low
because too many electrical consumers are
switched on.
XSwitch off electrical consumers which you
do not need, such as the rear window
defroster or interior lighting.
Steering wheel
Important safety notes
GWARNING
Do not adjust the steering wheel while driving.
Adjusting the steering wheel while driving
could cause the driver to lose control of the
vehicle.
The electrical steering wheel adjustment
feature can be operated at any time.
Therefore, do not leave children unattended
in the vehicle, or with access to an unlocked
vehicle. A child's unsupervised access to a
vehicle could result in an accident and/or
serious personal injury.
98Steering wheelSeats, steering wheel and mirrors

Adjusting the steering wheel
electrically:To adjust the steering wheel height;To adjust the steering wheel position
(fore-and-aft adjustment)
i Related topics:
R EASY-ENTRY/EXIT feature
( Y page 99)
R Storing settings ( Y page 102)
Steering wheel heating
Switching on/off
The steering-wheel heating heats the leather
areas of the steering wheel.
XMake sure that the SmartKey is in position
2 in the ignition lock.XTo switch on/off: turn the lever in the
direction of arrow : or ;.
Indicator lamp = lights up or goes out.i The steering wheel heating may switch off
temporarily if:
R the temperature of the vehicle interior is
above 86 °F (30 °C)
R the temperature of the steering wheel is
above 95 °F (35 °C).
Indicator lamp = remains on.
Problems with the steering wheel
heating
If the steering wheel heating indicator lamp
on the lower left lever of the steering column
is flashing, the steering wheel heating has
switched off automatically. The vehicle's
electrical system voltage is too low because
too many electrical consumers are switched
on.
XSwitch off electrical consumers which you
do not need, such as the rear window
defroster or interior lighting.
Once the battery is sufficiently charged, the
steering wheel heating will switch back on
automatically.
EASY-ENTRY/EXIT system
Important safety notes
The EASY-ENTRY/EXIT feature makes getting
in and out of your vehicle easier.
You can activate and deactivate the EASY-
ENTRY/EXIT feature in the on-board
computer ( Y page 212).
GWARNING
You must make sure no one can become
trapped or injured by the moving steering
wheel when the easy-entry/exit feature is
activated.
To stop steering wheel movement, move
steering wheel adjustment stalk or press the
memory position switch.
Do not leave children unattended in the
vehicle, or with access to an unlocked vehicle.
Children could open the driver's door and
Steering wheel99Seats, steering wheel and mirrorsZ