2012 MERCEDES-BENZ S-Class warning

then sound and the · distance warning
lamp in the instrument cluster will light up.XBrake immediately in order to increase the
distance from the vehicle in front.
or
XTake evasive action provided it is safe to do
so.
If the driver and front passenger have their
seat belt fastened, PRE-SAFE ®
Brake can also
brake the vehicle automatically at speeds
from approximately 4 mph (7 km/h) to
approximately 124 mph (200 km/h).
Due to the nature of the system, particularly
complicated driving conditions may cause
unnecessary warnings or the unnecessary
intervention of PRE-SAFE ®
Brake. To stop the
braking action, you can either depress the
accelerator pedal further, activate kickdown
or release the brake pedal.
The braking action of PRE-SAFE ®
Brake is
ended automatically if:
R you maneuver to avoid the obstacle.
R there is no longer any danger of a rear-end
collision.
R there is no longer an obstacle detected in
front of your vehicle.
i USA only: this device has been approved
by the FCC as a "Vehicular Radar System".
The radar sensor system is intended for use
in an automotive radar system only.
Removing, altering or tampering with the
device will void any warranties, and is not
permitted by the FCC. Do not tamper with,
alter, or use in any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
i Canada only: this device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause interference,
and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the
device will void any warranties, and is not
permitted. Do not tamper with, alter, or use
in any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
With the help of the radar sensor system,
PRE-SAFE ®
Brake can detect obstacles that
are in front of your vehicle for an extended
period of time.
At speeds up to approximately 40 mph
(70 km/h), PRE-SAFE ®
Brake can also react
to stationary obstacles, for example stopped
or parked vehicles.
If you approach an obstacle and PRE-SAFE ®
Brake detects a risk of collision, the system
will initially alert you both visually and
acoustically. If you do not brake or take
evasive action, the system will warn you by
automatically braking the vehicle gently. If
there is an increased risk of collision,
preventative passenger protection measures
(PRE-SAFE ®
) are activated (Y page 55). If the
risk of collision remains at speeds of over
20 mph (30 km/h) and you do not brake, take
evasive action or accelerate significantly, the
vehicle may perform automatic braking up to
emergency braking. Automatic emergency
braking is not performed until immediately
prior to an accident that can no longer be
avoided.GWARNING
Even if PRE-SAFE ®
Brake slows the vehicle
before an imminent rear-end collision, the
system cannot avert a collision without the
intervention of the driver. There is a risk of an
accident. Brake according to the situation or
take evasive action. Delayed intervention by
the driver can lead to an accident.
74Driving safety systemsSafety

GWARNING
PRE-SAFE®
Brake cannot always detect
complex traffic situations properly.
In these cases, PRE-SAFE(R) Brake may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
There is a risk of an accident. Always pay
particular attention to the traffic situation and
be ready to brake, especially if PRE-SAFE(R)
Brake warns you. Terminate the intervention
in a non-critical driving situation.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R the possibility of strong radar reflections,
for example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
GWARNING
PRE-SAFE ®
Brake does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R in curves
As a result, PRE-SAFE ®
Brake cannot
intervene in critical situations. There is a risk
of an accident. Always pay careful attention
to the traffic situation and be ready to brake.
In order to maintain the appropriate distance
to the vehicle in front and thus prevent a
collision, you must apply the brakes yourself.
XTo activate/deactivate: activate or
deactivate PRE-SAFE ®
Brake in the on-
board computer ( Y page 384).
After activation, the Ä symbol is
displayed on the left in the instrument
cluster.
For PRE-SAFE ®
Brake to assist you when
driving, the radar sensor system must be
switched on ( Y page 387) and operational.
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensors checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle.
Theft deterrent locking systems
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
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.
XTo activate with the SmartKey: remove
the SmartKey from the ignition lock.XTo activate with KEYLESS-GO: switch the
ignition off and open the driver's door.XTo deactivate: switch on the ignition.
i
The immobilizer is always deactivated
when you start the engine.
ATA (Anti-Theft Alarm system)
A visual and audible alarm is triggered if the
alarm system is armed and you open:
R a door
R the vehicle with the mechanical key
R the trunk lid
R the hood
Theft deterrent locking systems75SafetyZ

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 could 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 82).XUnlock the driver's door using the
mechanical key ( Y page 87).XLock the vehicle ( Y page 88).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
General notes
i USA only:
This device complies with Part 15 of the
FCC Rules. Operation is subject to the
following two conditions:
1. This device may not cause harmful
interference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation.
78SmartKeyOpening/closing

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
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 battery
XPress 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 82)
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.
Changing the battery
You require a CR 2025 3 V cell battery.
XTake the mechanical key out of the
SmartKey ( Y page 81).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.82SmartKeyOpening/closing

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 in
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 478).
or
XJump-start the vehicle ( Y page 481).
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.Doors85Opening/closingZ

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
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 67).
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 75).
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
The vehicle locks automatically when the
ignition is switched on and the wheels of the
86DoorsOpening/closing

vehicle are turning at a speed of more than
9 mph (15 km/h).
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 264).
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 75).
XTake the mechanical key out of the
SmartKey ( Y page 81).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.Doors87Opening/closingZ

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)
88TrunkOpening/closing