2012 MERCEDES-BENZ SLK250 door lock

of your shoulder and the lap section across
your hips.
X Engage belt tongue 0003in buckle 0023.
X If necessary, pull upwards on the shoulder
section of the seat belt to tighten the belt
across your body.
The seat belt on the front-passenger side is
equipped with a special seat belt retractor to
securely fasten a child restraint system in the
front-passenger seat. For further information
about special seat belt retractors, see
(Y page 55).
For more information about releasing the seat
belt with release button 0022, see "Releasing
seat belts" (Y page 51).
Seat belt adjustment i
AMG vehicles do not include the seat-belt
adjustment function.
The seat-belt adjustmen tfunction adjusts the
driver's and front-passenger seat belt to the
upper body of the occupants.
The belt strap is tightened slightly when:
R you engage the belt tongue in the belt
buckle and you then turn the SmartKey to
position 2in the ignition lock.
R the SmartKey is in position 2in the ignition
loc ka nd you then engage the belt tongue
in the buckle.
The seat-belt adjustment will apply a
retraction force if any slack is detected
between the occupant and the sea tbelt. Do
not hold on to the seat belt tightly while it is
adjusting. You can switch the seat-belt
adjustment on and off in the on-board
computer (Y page 194).
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. More
information about PRE-SAFE ®
can be found
in the "PRE-SAFE ®
(preventative occupant
protection)" section (Y page 47). Releasing seat belts X
Press release button 0022(Ypage 50) and
guide belt tongue 0003back towards belt
loop 0002.
! Make sure that the seat belt is fully rolled
up. Otherwise, the seat belt or belt tongue
will be trapped in the door or in the seat
mechanism. This could damage the door,
the door trim panel and the seat belt.
Damaged seat belts can no longer fulfill
their protective function and must be
replaced. Visit a qualified specialist
workshop.
Belt warning for the driver and front
passenger Regardless of whether the driver's and front-
passenger seat belts have already been
fastened, the
001Aseat belt warning lamp will
light up for six seconds each time the engine
is started. It then goes out if the driver and
the fron tpassenger have fastened their seat
belts.
If the driver's seat belt is no tfastened when
the engine is started, an additional warning
tone will sound. The warning tone goes out
after approximately six seconds or once the
driver's seat belt is fastened.
If after six seconds the driver's or front-
passenger seat belt is no tfastened and the
doors are closed, the 001Aseat belt warning
lamp will remain lit:
R until the driver's or fron tpassenger's seat
belt is fastened
R once the vehicle has exceeded a speed of
15 mph (25 km/h), in addition a warning
tone will sound with increasing intensity for
up to 60 seconds or until the driver's or
front-passenger seat belt is fastened.
If the driver or fron tpassenger unfastens their
seat belt during the journey, the 001Aseat
belt warning lamp lights up and the warning
tone sounds again. Occupant safety
51Safety Z

R
When securing a child in achild restraint
system on the front-passenger seat, you
must:
- move the front-passenger seat as far
back as possible
- use a child restraint system that is
suitable for the age, size and weight of
the child
- observe the manufacturer's installation
instructions in order to install and secure
the child restraint system correctly.
R For children larger than the typical 12-
month-old child, the front-passenger front
air bag may or may not be activated. G
WARNING
Infants and small children should never share
a seat belt with another occupant. In the event
of an accident, they could be crushed
between the occupant and seat belt.
Ac hild's risk of serious or fatal injuries is
significantly increased if the child restraints
are not properly secured in the vehicle and/
or the child is not properly secured in the child
restraint.
Children that are too large for a child restraint
must travel in seats using normal seat belts.
Position the shoulder belt across the chest
and shoulder, not face or neck.Ab ooster seat
may be necessary to achieve proper seat belt
positioning for children over 41 lb (18 kg) until
they reach a height where a lap-shoulder belt
fits properly without a booster.
When the child restraint is not in use, remove
it from the vehicle or secure it with the seat
belt to prevent the child restraint from
becoming a projectile in the event of an
accident.
If an infant or child is traveling in the vehicle:
X Secure the infant or child with an
appropriate infant or child restraint recommended for the child's age and
weight.
X Make sure that the infant or child is
properly secured at all times while the
vehicle is in motion. G
WARNING
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 unattended in the
vehicle, even if they are secured in a child
restraint system, or with access to an
unlocked vehicle. Achild's unsupervised
access to a vehicle could result in an accident
and/or serious personal injury. The children
could:
R injure themselves on parts of the vehicle
R be seriously or fatally injured through
excessive exposure to extreme heat or cold
R injure themselves or cause an accident with
vehicle equipment that can be operated
even if the SmartKey is removed from the
ignition lock or removed from the vehicle,
such as seat adjustment, steering wheel
adjustment, or the memory function
If children open a door, they could injure other
persons or get out of the vehicle and injure
themselves or be injured by following 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 the child could be burned on these
parts. G
WARNING
Do not carry heavy or hard objects in the
passenger compartmentu nless 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 54
Children in the vehicleSafety

G
WARNING
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. G
WARNING
PRE-SAFE ®
Brake cannot always detect
comple xtraffic 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 rada rsources
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 G
WARNING
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.
X
To activate/deactivate: activate or
deactivate PRE-SAFE ®
Brake in the on-
board computer (Y page 190).
The 0001 symbol appears in the
multifunction display as long as the HOLD
function is not activate d(Ypage 168).
On vehicles with Parking Guidance, the
0001 symbol is displayed when Pis
engaged or is selected or if you drive faster
than 22 mph (35 km/h).
For PRE-SAFE ®
Brake to assist you when
driving, the radar senso rsystem mus tbe
switched on (Y page 194) and be
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 system
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.
X To activate with the SmartKey: remove
the SmartKey from the ignition lock.
X To activate with KEYLESS-GO: switch the
ignition off and open the driver's door.
X To deactivate: switch on the ignition.
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 64
Theft deterrent locking systemSafety

Cente
rorcall 1-800-FOR-MERCedes (in
USA) or 1-800-387-0100 (in Canada). ATA (anti-theft alarm system)
Av isual 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
R the glove box
R the stowage space under the armrest
The alarm is not switched off, even if you
close the open door that has triggered it, for
example.
i If the alarm stays on for more than
30 seconds, the mbrace (USA only) or TELE
AI D( Canada only) emergency call system
initiates a call to the Custome rAssistance
Center automatically. The emergency call
system initiates the call provided that:
R you have subscribed to the mbrace/
TELE AID service.
R the mbrace/TELE AID service has been
activated properly.
R the required mobile phone, power supply
and GPS are available. X
To arm: lock the vehicle with the SmartKey
or KEYLESS-GO.
Indicator lamp 0002flashes. The alarm
system is armed after approximately
15 seconds.
X To disarm: unlock the vehicle with the
SmartKey or KEYLESS-GO.
X To stop the alarm using the SmartKey:
insert the SmartKey into the ignition lock.
The alarm is switched off.
or
X Press the 0010or000F button on the
SmartKey.
The alarm is switched off.
X To stop the alarm using KEYLESS-GO:
grasp the outside door handle. The
SmartKey must be outside the vehicle.
The alarm is switched off.
or
X Press the Start/Stop button on the
dashboard. The SmartKey must be inside
the vehicle.
The alarm is switched off. Theft deterrent locking system
65Safety Z

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 23).SmartKey
Important safety notes
G
WARNING
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. Achild'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.
G
WARNING
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.
X Check the battery in the SmartKey and
replace it if necessary (Y page 71).
X Unlock the driver's door using the
mechanical key (Y page 76).
X Lock the vehicle using the mechanical key
(Y page 76).
X Have 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 glove box
R the stowage compartment in the center
console
R the fuel filler flap 68
SmartKeyOpening/closing

0002
000F Locks the vehicle
0003 0006 Unlocks the trunk lid
0023 0010 Unlocks the vehicle
When unlocking, the turn signals flash once.
When locking, they flash three times.
When it is dark, the surround lighting also
comes on if it is activated in the on-board
computer (Y page 193).
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 194).
X To unlockc entrally:press the0010
button.
If you do not open th evehicle within
approximately 40 seconds of unlocking:
R the vehicle is locked again.
R the thef tdeterrent locking system is armed
again.
X To lock centrally: press the000Fbutton. KEYLESS-GO
Important notes on the use of KEYLESS-
GO R
Do not keep the KEYLESS-GO key together
with:
- electronic devices, e.g. a mobile phone
or another key
- metallic objects, e.g. coins or metal foil. This can affect the functionality of
KEYLESS-GO.
R Bear in mind that the engine can be started
by any of the vehicle occupants if there is
a KEYLESS-GO key in the vehicle.
Locking and unlocking centrally You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry
the SmartKey with you. You can combine the
KEYLESS-GO functions with those of a
conventional key, e.g. using KEYLESS-GO to
unlock and pressing the
000Fbutton to lock.
When locking and unlocking using KEYLESS-
GO, the distance between the SmartKey and
the corresponding door handle must not
exceed 3 ft (1 m).
KEYLESS-GO checks whether a valid key is in
the vehicle by periodically establishing a radio
connection between the vehicle and the key.
This happens:
R when the external door handles are
touched
R when starting the engine
R while the vehicle is in motion X
To unlock the vehicle: touch the inner
surface of the door handle.
X To lock the vehicle: touch sensor
surface 0002.
X Convenience closing feature: touch
recessed sensor surface 0003for an
extended period (Y page 81). SmartKey
69Opening/closing Z

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 settings of the locking
system so that when unlocking, only the
driver's door, the lockabl estowage
compartments in the vehicle interior 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 0010and000F buttons
simultaneously for approximately
si xs econds until the battery chec klamp
flashes twice ( Ypage 71).
i If the setting of the locking system is
changed within the signal range of the
vehicle, pressing the 000For0010 button
locks or unlocks the vehicle.
The SmartKey now functions as follows:
X To unlock the driver's door: press the
0010 button once.
X To unlock centrally: press the0010
butto ntwice.
X To lock centrally: press the000Fbutton.
The KEYLESS-GO function is changed as
follows:
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
surface of the front-passenger door handle.
X To lock centrally: touch the outersensor
surface on one of the door handles. Restoring the factory settings
X Press the 0010and000F buttons
simultaneously for approximately
six seconds until the battery chec klamp
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-thef talarm system will be triggered
(Y page 65).
There are several ways to tur noff the alarm:
X To turn the alarm off with the
SmartKey: press the0010or000F 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
ignition 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 fla pwill not be unlocked
automatically.
X To unlock the fuel filler flap: insert the
SmartKey in the ignition lock.
Removing the mechanical key 70
SmartKeyOpening/closing

Problems with the SmartKey
Problem Possible causes/consequences and
0001 Solutions
You 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 0010/
000F button.
If this does not work:
X Check the SmartKey battery (Y page 71) and replace it if
necessary (Y page 71).
X Lock (Y page 76) or unlock (Y page 76) the vehicle using
the mechanical key. The SmartKey is faulty.
X
Lock (Y page 76) or unlock (Y page 76) the vehicle using
the mechanical key.
X Have 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.
X 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 0010/000Fbutton. There is a malfunction with KEYLESS-GO.
X 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 0010/000Fbutton.
X Have KEYLESS-GO checked at a qualified specialist workshop.
If this does not work:
X Check the SmartKey battery (Y page 71) and replace it if
necessary (Y page 71).
X Lock (Y page 76) or unlock (Y page 76) the vehicle using
the mechanical key. 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. SmartKey
73Opening/closing Z