2015 MERCEDES-BENZ C-Class COUPE door lock

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
The alarm is not switched off, even if you
close the open door that triggered it, for
example.
i If the alarm continues for more than
30 seconds, the mbrace emergency call
system automatically notifies the Cus-
tomer Assistance Center. This is done
either by text message or data connection. The emergency call system sends the mes-sage or data provided that:
R you have subscribed to the mbrace ser-
vice.
R the mbrace service has been activated
properly.
R the necessary mobile phone network is
available. X
To arm: lock the vehicle with the SmartKey
or KEYLESS-GO.
Indicator lamp 0043flashes. The alarm sys-
tem is armed after approximately
15 seconds.
X To deactivate: 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 0036or0037 button on the
SmartKey.
The alarm is switched off.
X To stop the alarm using KEYLESS-GO:
grasp the outside door handle. The Smart-
Key must be outside the vehicle.
The alarm is switched off.
or X Press the Start/Stop button on the dash-
board. The SmartKey must be inside the
vehicle.
The alarm is switched off. 72
Protection against theftSafety

Useful information
i This Operator's Manual describes all
models and all standard and optional equip- ment 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 Read the information on qualified special-
ist workshops (Y page 26). SmartKey
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 shifting the automatic transmission out of
park position P
R Start 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. G
WARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be uninten-
tionally turned in the ignition lock. This could
cause the engine to be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to the
SmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
! Keep the SmartKey away from strong
magnetic fields. Otherwise, the remote
control function could be affected.
Strong magnetic fields can occur in the
vicinity of powerful electrical installations.
R Do not keep the KEYLESS-GO key:
- with electronic devices, e.g. a mobile
phone or another SmartKey
- with metallic objects, e.g. coins or metal
foil
- inside metallic objects e.g. a metal case
This can affect the functionality of the
SmartKey. SmartKey functions
The SmartKey centrally locks/unlocks:
R the doors
R the trunk lid
R the fuel filler flap 0043
0037 To lock the vehicle
0044 0054 To unlock the trunk lid
0087 0036 To unlock the vehicle 74
SmartKeyOpening and closing

The turn signals flash once when unlocking
and three times when locking.
When it is dark, the surround lighting also
comes on if it is activated in the on-board
computer (Y page 202).
You can also set an audible signal to confirm that the vehicle has been locked. The audiblesignal can be activated and deactivated using
the on-board computer (Y page 203).
X To unlock centrally: press the0036but-
ton.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
R the vehicle is locked again.
R the theft deterrent locking system is armed
again.
X To lock centrally: press the0037button. KEYLESS-GO
General notes Bear in mind that the engine can be started by
any of the vehicle occupants if there is a KEY-LESS-GO key in the vehicle.
Locking/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
functions of KEYLESS-GO with those of a con- ventional SmartKey. Unlock the vehicle by
using KEYLESS-GO, for instance, and lock it
using the 0037button on the SmartKey.
When locking or unlocking with KEYLESS-GO,
the distance between the SmartKey and the
corresponding door handle must not be
greater than 3 ft (1 m). KEYLESS-GO checks whether a valid Smart-
Key is in the vehicle by periodically establish-
ing a radio connection between the vehicle
and the SmartKey. 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 sur-
face 0043.
X Convenience closing feature: touch
recessed sensor surface 0044for an exten-
ded period.
Further information on the convenience clos-
ing feature (Y page 87).
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. This means that only the driver's door and the fuel filler flap are unlocked when the
vehicle is unlocked. This is useful if you fre-
quently travel on your own.
X To change the setting: press and hold
down the 0036and0037 buttons simulta-
neously for approximately six seconds until
the battery check lamp (Y page 77)
flashes twice. SmartKey
75Opening and closing Z

i
If the setting of the locking system is
changed within the signal range of the vehi- cle, pressing the 0037or0036 button:
R locks or
R unlocks the vehicle
The SmartKey now functions as follows:
X To unlock the driver's door: press the
0036 button once.
X To unlock centrally: press the0036but-
ton twice.
X To lock centrally: press the0037button.
The KEYLESS-GO function is changed as fol-
lows:
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 sur-
face of the front-passenger door handle.
X To lock centrally: touch the outer sensor
surface on one of the door handles
(Y page 75).
X To restore the factory settings: press
and hold down the 0036and0037 buttons
simultaneously for approximately six sec-
onds until the battery check lamp flashes
twice. Mechanical key
General notes If the vehicle can no longer be locked or
unlocked with the SmartKey or the KEYLESS- GO key, 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 72).
X To end the alarm: insert the SmartKey into
the ignition lock.
i With KEYLESS-GO:
remove the Start/
Stop button from the ignition lock before-
hand. 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 0043in the direction of
the arrow and at the same time remove
mechanical key 0044from the SmartKey.
Inserting the mechanical key X
Push mechanical key 0044completely into
the SmartKey until it engages, and release
catch 0043is back in its basic position. SmartKey battery
Important safety notes Mercedes-Benz recommends that you have
the batteries replaced at a qualified specialist
workshop. G
WARNING
Batteries contain toxic and corrosive substan- ces. 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. 76
SmartKeyOpening and closing

Problems with the SmartKey
Problem
Possible causes/consequences and
0050
0050Solutions 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 0036or
0037 button.
If this does not work:
X Check the SmartKey battery (Y page 77) and replace it if nec-
essary (Y page 77).
X Lock (Y page 81) or unlock (Y page 81) the vehicle using the
mechanical key. The SmartKey is faulty.
X Lock (Y page 81) or unlock (Y page 81) 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 0036/0037 button. 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 0036/0037 button.
X Have KEYLESS-GO checked at a qualified specialist workshop.
If this does not work: X Check the SmartKey battery (Y page 77) and replace it if nec-
essary (Y page 77).
X Lock (Y page 81) or unlock (Y page 81) the vehicle using the
mechanical key. You have lost a Smart-
Key. X
Have the SmartKey deactivated at a qualified specialist work-
shop.
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. 78
SmartKeyOpening and closing

Problem
Possible causes/consequences and
0050
0050Solutions The 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 290).
or
X Jump-start the vehicle (Y page 294).
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. 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.
X Close the door and try to start the vehicle again. There is interference from a powerful source of radio waves.
X Start your vehicle with the SmartKey in the ignition lock. 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 shifting the automatic transmission out of
park position P
R Start 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.
You should preferably place luggage or loads
in the trunk. Observe the loading guidelines
(Y page 248). Doors
79Opening and closing Z

Unlocking and opening doors from
the inside
You can open a door from inside the vehicle
even if it has been locked.
You can open a 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 Smart- Key or with KEYLESS-GO, opening a door from
the inside will trigger the anti-theft alarm sys- tem. Switch off the alarm (Y page 72).X
To unlock a front door: pull door han-
dle 0044.
Locking knob 0043pops up.
The door is unlocked and can be opened.
X To open a front door: pull door handle0044.
X To unlock a rear door: pull up locking
knob 0043.
The door is unlocked and can be opened.
X To open a rear door: pull door handle0044. Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle
from the inside.
You cannot unlock the vehicle centrally from
the inside if the vehicle has been locked with the SmartKey or KEYLESS-GO. X
To unlock: press button 0043.
X To lock: press button 0044.
If the front-passenger door is closed, the
vehicle locks.
Meanwhile, the fuel filler flap will not be
locked or unlocked.
You can open a door from inside the vehicle
even if it has been locked.
You can open a door from inside the vehicle
even if it has been locked.
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 72).
If a locked door is opened from the inside, the
previous unlock status of the vehicle will be
taken into consideration if:
R the vehicle was locked using the locking
button for the central locking, or
R if the vehicle was locked automatically
The vehicle will be fully unlocked if it had pre- viously been fully unlocked. If only the driver's
door had been previously unlocked, only the
door which has been opened from the inside
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. 80
DoorsOpening and closing

Automatic locking feature
The vehicle is locked automatically when the
ignition is switched on and the vehicle's
wheels are turning at a speed in excess of
9 mph (15 km/h).
You could therefore be locked out if:
R the vehicle is being pushed.
R the vehicle is being towed.
R the vehicle is on a roller dynamometer. X
To deactivate: press and hold button 0043
for about five seconds until a tone sounds.
X To activate: press and hold button 0044for
about five seconds until a tone sounds.
i If you press one of the two buttons and do
not hear a tone, the relevant setting has
already been selected.
You can also switch the automatic locking
function on and off using the on-board com-
puter (Y page 203). Unlocking the driver's door (mechan-
ical 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 72).
X Take the mechanical key out of the Smart-
Key (Y page 76).
X Insert the mechanical key into the lock of
the driver's door as far as it will go. X
Turn the mechanical key counter-clockwise
as far as it will go to position 0047.
The door is unlocked.
X Turn the mechanical key back and remove
it.
X Insert the mechanical key into the Smart-
Key (Y page 76). Locking the vehicle (mechanical key)
If the vehicle can no longer be locked with the
SmartKey, use the mechanical key.
X Open the driver's door.
X Close the front-passenger door and the
trunk lid.
X Press the locking button (Y page 80).
X Check whether the locking knob on the
front-passenger door is still visible. Press
the locking knob down by hand, if neces-
sary (Y page 80).
X Close the driver's door.
X Take the mechanical key out of the Smart-
Key (Y page 76).
X Insert the mechanical key into the lock of
the driver's door as far as it will go. Doors
81Opening and closing Z