2014 MERCEDES-BENZ C-Class SEDAN Owner's Manual

Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately.
Checking the battery X
Press the 000Aor000B button.
The battery is working properly if battery
check lamp 0002lights up briefly.
If battery check lamp 0002does not lightup
briefly during the test, the battery is
discharged.
i If the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the 000Aor000B button:
R locks or
R unlocks the vehicle
X Change the battery (Y page 79).
i You can get a battery at a qualified
specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X Take the mechanical key out of the
SmartKey (Y page 78). X
Press mechanical key 0003intothe SmartKey
opening in the direction of the arrow until
battery compartment cover 0002opens. Do
not hold battery compartment cover 0002
closed while doing so.
X Remove battery compartment cover 0002. X
Repeatedly tap the SmartKey against your
palm until battery 0022falls out.
X Insert the new battery with the positive
terminal facing upwards. Use a lint-free
cloth to do so.
X Make sure that the surface of the battery is
free from lint, grease and all other forms of
contamination.
X Insert the front tabs of battery
compartment cover 0002into the housing
first and then press to close it.
X Insert mechanical key 0003into the
SmartKey.
X Check the function of all SmartKey buttons
on the vehicle. SmartKey
79Opening and closing Z

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 000Bor
000A button.
If this does not work:
X Check the SmartKey battery (Y page 79) and replace it if
necessary (Y page 79).
X Lock (Y page 83) or unlock (Y page 83) the vehicle using
the mechanical key. The SmartKey is faulty.
X
Lock (Y page 83) or unlock (Y page 83) 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 000B/000A 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 000B/000A button.
X Have KEYLESS-GO checked at a qualified specialist workshop.
If this does not work:
X Check the SmartKey battery (Y page 79) and replace it if
necessary (Y page 79).
X Lock (Y page 83) or unlock (Y page 83) 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. 80
SmartKeyOpening and closing

Problem Possible causes/consequences and
0001 Solutions
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 302).
or
X Jump-start the vehicle (Y page 306).
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. Ad
oor 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 cargo compartment. Observe the
loading guidelines (Y page 262). Doors
81Opening 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 only open
the rear doors from inside the vehicle if they
are not secured by the child-proof locks
(Y page 64).
Only open the door when the traffic situation
permits.
If the vehicle has been locked with the
SmartKey or with KEYLESS-GO, opening a
door from the inside will trigger the anti-theft
alarm system. Switch off the alarm
(Y page 73). X
To unlock a front door: pull door
handle 0003.
Locking knob 0002pops up.
The door is unlocked and can be opened.
X To open a front door: pull door
handle 0003.
X To unlock a rear door: pull up locking
knob 0002.
The door is unlocked and can be opened.
X To open a rear door: pull door handle0003. 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 0002.
X To lock: press button 0003.
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 only open
the rear doors from inside the vehicle if they
are not secured by the child-proof locks
(Y page 64).
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 73).
If the vehicle has been locked using the
locking button for the central locking, or has
been locked automatically, and a door is
opened from the inside:
R the vehicle will be fully unlocked if it had
previously been fully unlocked
R only the door which has been opened form
the inside is unlocked if only the driver's
door had been previously 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. 82
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 locke dout 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 0002
for about five seconds until a tone sounds.
X To activate: press and hold button 0003for
about five seconds until a tone sounds.
i If you press one of th etwo 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
computer (Y page 217). 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 unloc kand
open the driver's door, the anti-thef talarm
system will be triggered ( Ypage 73).
X Take the mechanical key out of the
SmartKey (Y page 78).
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
to position 0005.
The door is unlocked.
X Turn the mechanical key back and remove
it.
X Insert the mechanical key into the
SmartKey. 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, the rear
doors and the trunk lid.
X Press the locking button (Y page 82).
X Check whether the locking knobs on the
front-passenger door and the rear doors
are still visible. Press down the locking
knobs manually, if necessary ( Ypage 82).
X Close the driver's door.
X Take the mechanical key out of the
SmartKey (Y page 78).
X Insert the mechanical key into the lock of
the driver's door as far as it will go. Doors
83Opening and closing Z

X
Turn the mechanical key clockwise as far
as it will go to position 0005.
X Turn the mechanical key back and remove
it.
X Make sure that the doors and the trunk lid
are locked.
X Insert the mechanical key into the
SmartKey.
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
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
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the
trunk lid is open when the engine is running,
especially if the vehicle is in motion .There is
a risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open. !
The trunk lid swings upwards when
opened. Therefore, make sure that there is
sufficient clearance above the trunk lid.
i Opening dimensions of the trunk lid
(Y page 358).
You should preferably place luggage or loads
in the cargo compartment. Observe the
loading guidelines (Y page 262).
Do not leave the SmartKey in the trunk. You
could otherwise lock yourself out.
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 Trunk lid reversing feature
The trunk lid is equipped with an automatic
reversing feature. It reacts if a solid object
obstructs or restricts the trunk lid during the
closing procedure. The trunk lid opens again
automatically .The automatic reversing
feature is only an aid and is not a substitute
for your attentiveness to the trunk lid while it
is closing. G
WARNING
The reversing feature does not react:
R to soft, light and thin objects, e.g. small
fingers
R over the last 1/3 in(8 mm) of the closing
movement
This means that the reversing feature cannot
prevent someone being trapped in these
situations. There is a risk of injury.
Make sure that no body parts are in close
proximity during the closing procedure. 84
TrunkOpening and closing

If somebody becomes trapped:
R
press the 0004button on the SmartKey, or
R press the remote operating switch on the
driver's door, or
R press the closing or locking button on the
trunk lid, or
R pull on the trunk lid handle Opening/closing from outside
Opening X
Press the 000Bbutton on the SmartKey. X
Pull handle 0002.
X Raise the trunk lid.
Closing X
Pull the trunk lid down using recess 0002.
X If necessary, lock the vehicle with
the 000A button on the SmartKey
(Y page 76) or with KEYLESS-GO
(Y page 77). i
If a KEYLESS-GO key is detected in the
trunk, the trunk lid cannot be locked and
will open again. Opening automatically from outside
Important safety notes G
WARNING
Parts of the body could become trapped
during automatic closing of the trunk lid.
Moreover, people, e.g. children, may be
standing in the closing area or may enter the
closing area during the closing process. There
is a risk of injury.
Make sure that nobody is in the vicinity of the
closing area during the closing process.
Use one of the following options to stop the
closing process:
R Press the 0004button on the key.
R press the remote operating switch on the
driver's door.
R Press the closing or locking button on the
trunk lid.
R Pull the trunk lid handle. G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the
trunk lid is open when the engine is running,
especially if the vehicle is in motion. There is
a risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
! The trunk lid swings upwards when
opened. Therefore, make sure that there is
sufficient clearance above the trunk lid.
i Opening dimensions of the trunk lid
(Y page 358). Trunk
85Opening and closing Z

Opening
You can open the trun
klid automatically
using the SmartKey or the handle in the trunk
lid.
X Press and hold the 0004button on the
SmartKey until the trunk lid opens.
or
X If the trunk lid is unlocked, pull the trunk lid
handle and let it go again immediately. Opening automatically from inside
G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide .Exhaust
gases can enter the vehicle interior if the
trunk lid is ope nwhen the engine is running,
especially if the vehicle is in motion. There is
a risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
! The trunk lid swings upwards when
opened. Therefore, make sure that there is
sufficient clearance above the trunk lid.
i Opening dimensions of the trunk lid
(Y page 358).
You can open the trunk lid from the driver's
seat when the vehicle is stationary and
unlocked. X
To open: press the upper section of the
remote operating switch for trunk lid 0002
until the trunk lid opens. Locking the trunk separately
You can lock the trunk separately.Ify ou then
unlock the vehicle centrally, the trunk
remains locked and cannot be opened.
X Close the trunk lid.
X Take the mechanical key out of the
SmartKey (Y page 78). X
Insert the mechanical key into the trunk lid
lock as far as the stop.
X Turn the mechanical key clockwise from
position 0005to position 0006.
X Remove the mechanical key.
X Insert 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 73).86
TrunkOpening and closing