2012 MERCEDES-BENZ S-CLASS SEDAN child lock

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops ( Y page 31).
SmartKey
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
If a key ring is too heavy or too large, the
weight acting on the key could cause it to turn
in the ignition lock or catch on the steering
wheel. This could cause the engine to be
switched off suddenly. You may lose control
of the vehicle and cause an accident. Do not
attach any heavy or large key rings to the key
that is inserted in the ignition.
General notes
If you cannot lock or unlock the vehicle with
the SmartKey, either the battery in the
SmartKey is discharged, the SmartKey is
faulty or the starter battery is discharged.
XCheck the battery in the SmartKey and
replace it if necessary ( Y page 85).XUnlock the driver's door using the
mechanical key ( Y page 90).XLock the vehicle ( Y page 91).XHave the starter battery and the battery
contacts checked at a qualified specialist
workshop.
If the SmartKey is faulty, contact Roadside
Assistance or a qualified specialist workshop.
SmartKey functions
The SmartKey centrally locks/unlocks:
R the doors
R the trunk lid
R the fuel filler flap
82SmartKeyOpening/closing

Removing the mechanical keyXPush release catch : in the direction of
the arrow and at the same time, remove
mechanical key ; from the SmartKey.
SmartKey battery
Important safety notes
Have the batteries changed at a qualified
specialist workshop.
GWARNING
Batteries contain toxic substances.
Swallowing batteries can lead to serious
health issues or death.
Keep batteries out of the reach of children.
Seek medical attention immediately if a
battery is swallowed.
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 batteryXPress the & or % button.
The battery is working properly if battery
check lamp : lights up briefly
If battery check lamp : does not light up
briefly during the test, the battery is
discharged.
XChanging the battery ( Y page 85)
i
You can obtain the battery at a qualified
specialist workshop.
i If the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the & or % button locks or
unlocks the vehicle.
Replacing the battery
You require a CR 2025 3 V cell battery.
XTake the mechanical key out of the
SmartKey ( Y page 84).XPress mechanical key ; into the opening
in the SmartKey in the direction of theSmartKey85Opening/closingZ

ProblemPossible causes/consequences and M SolutionsYou have lost the
mechanical key.XReport the loss immediately to the vehicle insurers.XIf necessary, have the locks changed as well.The engine cannot be
started using the
SmartKey.The on-board voltage is too low.XRemove the SmartKey and reinsert it into the ignition lock.XStart the engine within 30 seconds of inserting the SmartKey
into the ignition lock.XRepeat if necessary.
If the engine does not start after several attempts:
XCheck the starter battery and charge it if necessary
( Y page 480).
or
XJump-start the vehicle ( Y page 483).
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.88DoorsOpening/closing

GWARNING
Do not carry heavy or hard objects in the
passenger compartment 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
Unlocking and opening doors from
the inside
You can open a door from inside the vehicle
even if it has been locked. You can only open
the rear doors from inside the vehicle if they
are not secured by the child-proof locks
( Y page 71).
Only open the door when the traffic situation
permits.
If the vehicle was previously locked with the
SmartKey or with KEYLESS-GO, opening the
vehicle from the inside will activate the anti-
theft alarm system. Switch off the alarm
( Y page 79).
XPull door handle ;.
If the door is locked, locking knob : pops
up. The door is unlocked and can be
opened.Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle
from the inside.
The central locking/unlocking button does
not lock or unlock the fuel filler flap.
i You cannot unlock the vehicle centrally
from the inside if the vehicle has been
locked with the SmartKey or KEYLESS-GO.XTo unlock: press button :.XTo lock: press button ;.
If the front-passenger door is closed, the
vehicle locks.
You can open a front door from inside the
vehicle even if it has been locked. Only open
the door when the traffic situation permits.
If the vehicle has been locked with the central
locking button:
R and the SmartKey is set to its factory
setting, the entire vehicle is unlocked if a
front door is opened from the inside
R and the SmartKey is set to an individual
setting, only the front door that is opened
from inside the vehicle is unlocked.
If the vehicle has been locked centrally with
the SmartKey or with KEYLESS-GO, it is not
unlocked when the release button for the
central locking is used.
Automatic locking feature
When the ignition is switched on and the
wheels of the vehicle are turning at a speed
Doors89Opening/closingZ

of more than 9 mph (15 km/h), the vehicle
locks automatically.
You could therefore be locked out when:
R the vehicle is being pushed.
R the vehicle is being towed.
R the vehicle is being tested on a
dynamometer.
You can switch off the automatic locking
function via COMAND ( Y page 269).
Power closing feature
The power closing feature pulls the doors and
trunk lid into their locks automatically even if
they are only partly closed.
GWARNING
To prevent possible personal injury, always
keep hands and fingers away from the door or
trunk opening when closing a door or the
trunk lid. Be especially careful when small
children are around.
If danger threatens, pull the inside or outside
door handle, or pull the trunk lid handle.
To prevent personal injury, never activate the
closing assist mechanism by tampering with
the door or trunk lid latch.
GWARNING
Only drive with the doors closed. Otherwise,
one or more of the doors could open while the
vehicle is in motion, putting you and/or
others at risk.
GWARNING
Make sure the trunk lid is closed when the
engine is running and while driving. Among
other dangers, deadly carbon monoxide (CO)
gases may enter the vehicle interior resulting
in unconsciousness and death.
XPower closing feature (doors): push the
door past the first detent position of the
lock.
The power closing feature will pull the door
fully closed.XPower closing feature (trunk lid): lightly
push the trunk lid closed.
The power closing feature will pull the trunk
lid fully closed.
Unlocking the driver's door
(mechanical key)
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 79).
XTake the mechanical key out of the
SmartKey ( Y page 84).XInsert the mechanical key into the lock of
the driver's door as far as it will go.XFirmly turn the mechanical key
counterclockwise as far as it will go to
position 1 and hold it in this position.XPull the door handle quickly.
The locking knob pops up.
The door is unlocked.XTurn the mechanical key back and remove
it.XPull the door handle again.XInsert the mechanical key into the
SmartKey.90DoorsOpening/closing

Locking the vehicle
If the vehicle can no longer be locked with the
SmartKey, you can lock it by taking the
following steps. If the central locking in the
vehicle is malfunctioning, you cannot lock the
trunk.XPress down the locking knobs on the open
rear doors.XClose the rear doors.XOpen the front-passenger door.XClose the driver's door and the trunk lid.XPress down the locking knob of the driver's
door inside the vehicle.XPress down the locking knob of the open
front-passenger door.
i Make sure that you have the SmartKey on
your person and that it has not been left in
the vehicle.
XClose the front-passenger door.XMake sure that the doors and the trunk are
locked.
i If you lock the vehicle as described above,
the fuel filler flap is not locked. The anti-
theft alarm system is not armed.
Trunk
Important safety notes
Do not leave the SmartKey in the trunk. You
could otherwise lock yourself out.
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
GWARNING
Make sure the trunk lid is closed when the
engine is running and while driving. Among
other dangers, deadly carbon monoxide (CO)
Trunk91Opening/closingZ

gases may enter the vehicle interior resulting
in unconsciousness and death.
! The trunk lid swings upwards when
opened. Therefore, make sure that there is
sufficient clearance above the trunk lid.
You can limit the opening angle of the trunk
lid. This could be useful, for example, if there
is insufficient space above the trunk lid. You
can switch the Trunk Opening-height
Restriction function on or off via COMAND
( Y page 269).
To open the trunk lid completely, a minimum
clearance of 5.90 ft (1.80 m) above the
ground is necessary.
Vehicles without trunk lid remote closing
feature: the trunk lid can be:
R opened and closed manually from outside
R opened automatically from outside
R opened automatically from inside
R locked separately
R unlocked with the mechanical key
R opened with the emergency release button
Vehicles with trunk lid remote closing
feature: the trunk lid can be:
R opened and closed manually from outside
R opened and closed automatically from
outside
R opened and closed automatically from
inside
R locked separately
R unlocked with the mechanical key
R opened with the emergency release button
Opening and closing manually
Opening
XPress the % button on the SmartKey.XPull handle :.XRaise the trunk lid.
Closing
GWARNING
To prevent possible personal injury, always
keep hands and fingers away from the trunk
opening when closing the trunk lid. Be
especially careful when small children are
around.
XPull the trunk lid down using recess :.XIf necessary, lock the vehicle with
the & button on the SmartKey
( Y page 82) or with KEYLESS-GO
( Y page 83).
i
If a KEYLESS-GO key is detected in the
trunk, the trunk lid cannot be locked and
then opens again.
92TrunkOpening/closing

Opening/closing automatically from
outside
Important safety notesGWARNING
Make sure the trunk lid is closed when the
engine is running and while driving. Among
other dangers, deadly carbon monoxide (CO)
gases may enter the vehicle interior resulting
in unconsciousness and death.
! The trunk lid swings upwards when
opened. Therefore, make sure that there is
sufficient clearance above the trunk lid.
To open the trunk lid completely, a minimum
clearance of 5.90 ft (1.80 m) above the
ground is necessary.
Opening
You can open the trunk lid using the
SmartKey.
XPress and hold the F button on the
SmartKey until the trunk lid opens.
Closing
GWARNING
Monitor the closing procedure carefully to
make sure no one is in danger of being
injured. To prevent possible personal injury,
always keep hands and fingers away from the
trunk opening when closing the trunk lid. Be
especially careful when small children are
around. To stop the closing procedure, do one
of the following:
R Press button F on the SmartKey.
R Press the remote trunk opening/closing
switch (on the driver's door).
R Press the trunk closing switch.
R Press the KEYLESS-GO locking/closing
switch.
R Pull the trunk lid handle.
Even with the SmartKey removed from the
starter switch or the SmartKey with KEYLESS-
GO removed from the vehicle, the remote
trunk opening/closing switch can be
operated. 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.
You can close the trunk lid automatically by
using the closing button 3
or locking button 4
.XTo close: press closing button : in the
trunk lid.XTo close and lock simultaneously:
Press locking button ; in the trunk lid.
i
If you leave a KEYLESS-GO key in the
trunk, the trunk lid will not lock.
Opening/closing automatically from
inside
GWARNING
Maintain sight of the area around the rear of
the vehicle while operating the trunk lid with
the door mounted switch. Monitor the closing
procedure carefully to make sure no one is in
danger of being injured.
To interrupt the closing procedure, release
the door mounted remote trunk opening/
closing switch again.
3 For vehicles with the trunk lid remote closing feature only.
4 For vehicles with the trunk lid remote closing feature and KEYLESS-GO only.Trunk93Opening/closingZ