2016 MERCEDES-BENZ C CLASS key

X
Repeatedly tap th e SmartKey against your
palm until battery

Problems with the SmartKey Problem
Possible causes/consequences and P Solutions
You can no longer lock or
unlock the vehicle using
the SmartKey. The SmartKey battery is discharged or nearly discharged. X
Check the SmartKey battery ( Y
page 84) and replace it if necessary
( Y
page 84).
If this does not work: X
Unlock ( Y
page 89) or lock ( Y
page 89) the vehicle using the
mechanical key.
There is interference from a powerful source of radio waves. X
Unlock ( Y
page 89) or lock ( Y
page 89) the vehicle using the
mechanical key.
The SmartKey is faulty. X
Unlock ( Y
page 89) or lock ( Y
page 89) 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. KEYLESS-GO was deactivated. X
Reactivate KEYLESS-GO ( Y
page 82).
The SmartKey battery is discharged or nearly discharged. X
Check the SmartKey battery ( Y
page 84) and replace it if necessary
( Y
page 84).
If this does not work: X
Unlock ( Y
page 89) or lock ( Y
page 89) the vehicle using the
mechanical key.
There is interference from a powerful source of radio waves. X
Unlock ( Y
page 89) or lock ( Y
page 89) the vehicle using the
mechanical key.
KEYLESS-GO is malfunctioning. X
Lock/unlock the vehicle using the remote control function of the
SmartKey. X
Have the vehicle and SmartKey checked at a qualified specialist
workshop.
If the vehicle can also not be locked/unlocked using the remote con-
trol function: X
Unlock ( Y
page 89) or lock ( Y
page 89) the vehicle using the
mechanical key. X
Have the vehicle and SmartKey checked at a qualified specialist
workshop.86
SmartKey
Opening and closing

Problem
Possible causes/consequences and P Solutions
The engine cannot be
started using the Smart-
Key. 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 350).
or X
Jump-start the vehicle ( Y
page 352).
or X
Consult a qualified specialist workshop.
The engine cannot be
started using the Start/
Stop button. The Smart-
Key is in the vehicle. The vehicle is locked. X
Unlock the vehicle and try to start the vehicle again.
The SmartKey battery is discharged or nearly discharged. X
Check the SmartKey battery ( Y
page 84) and replace it if necessary
( Y
page 84).
If this does not work: X
Start your vehicle with the SmartKey in the ignition lock.
There is interference from a powerful source of radio waves. X
Start your vehicle with the SmartKey in the ignition lock.
You have lost a Smart-
Key. 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.
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. Doors 87
Opening 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 67). 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 79).
X
To unlock and open a front door: pull door
handle D .
If the door is locked, locking knob C pops up.
The door is unlocked and opens. X
To unlock a rear door: pull door handle D .
Locking knob C pops up and the door
unlocks. X
To open a rear door: pull door handle D
again.
The door opens.
Centrally locking and unlocking the
vehicle from the inside You can centrally lock and unlock the vehicle
from the inside. The switches are on the driver’s
door. X
To unlock: press button C .X
To lock: press button D .
When the front-passenger door is closed, the
vehicle is locked.
Meanwhile, the fuel filler flap will not be locked
or unlocked.
You cannot unlock the vehicle centrally from the
inside if the vehicle has been locked with the
SmartKey or KEYLESS-GO.
The doors can be opened from the inside. You
can only open the rear doors from inside the
vehicle if they are not secured by the child-proof
locks ( Y
page 67).
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 79).
When a locked door is opened from inside the
vehicle, the previous unlocking process will be
acknowledged if the vehicle: R
has been locked with the locking button for
the central locking or R
has been locked automatically
The vehicle will be fully unlocked if it had previ-
ously 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.88
Doors
Opening and closing

Aut oma tic locking featu reX
To deactivate: press and hold butto n C for
approximately fiv e seconds until a tone
sounds. X
To activate: press and hold butto n D for
approximately fiv e seconds until a tone
sounds.
If you press on e of th e two buttons and do no t
hear a tone , th e relevan t setting has already
been selected.
The vehicl e is locke d automatically when th e
ignition is switched on and th e wheels are turn-
ing .
You could therefor e be locke d out if:R
th e vehicl e is bein g pushed.R
th e vehicl e is bein g towed.R
th e vehicl e is on a roller dynamometer.
i You can also activat e and deactivat e th e
automatic locking function via COMAND or
Audio 20 (see th e Digital Operator' s Manual).
Unlocking/locking driver's door with
mechanical key
i If you want to centrally loc k th e vehicl e usin g
th e mechanical key, begi n by pressing th e
locking butto n for th e interior locking mech-
anism while th e driver's door is open . The n
loc k th e driver's door usin g th e mechanical
key. X
Inser t th e mechanical ke y int o opening C in
th e protective cap .X
Pull and hold th e door handle. X
Pull th e protective cap on th e mechanical ke y
as straight as possibl e away from th e vehicl e
until it releases. X
Releas e th e door handle.
X
To unlock: tur n th e mechanical ke y counter-
clockwise as far as it will go to position G .X
To lock: tur n th e mechanical ke y clockwise as
far as it will go to position G .
If you use th e mechanical ke y to unloc k and
open th e driver's door , th e anti-thef t alarm sys-
te m will be triggered . Switc h off th e alarm
( Y
page 79).
Trunk
Import ant safety notes
G WARNIN G
Combustion engines emi t poisonous exhaust
gase s suc h as carbon monoxide. Exhaust
gase s can ente r th e vehicl e interior if th e
trunk lid is open when th e engin e is running,Trunk 89
Opening and closing Z

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.
G WARNING
If objects, luggage or loads are not secured or
not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, particu-
larly in the event of sudden braking or a sud-
den change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
! The trunk lid swings upwards when opened.
Therefore, make sure that there is sufficient
clearance above the trunk lid.
The opening dimensions of the trunk lid can be
found in the "Vehicle data" section
( Y
page 394).
You can limit the opening angle of the trunk lid in
COMAND or Audio 20 (see the Digital Opera-
tor's Manual).
Do not leave the SmartKey in the trunk. You
could otherwise lock yourself out.
You should preferably place luggage or loads in
the trunk. Observe the loading guidelines
( Y
page 308).
Obstruction recognition with trunk lid
reversing feature Vehicles with trunk lid remote closing fea-
ture:
The trunk lid is equipped with automatic
obstruction detection with a reversing feature. If
a solid object blocks or restricts the trunk lid
when automatically opening, this procedure is
stopped. If a solid object blocks or restricts the
trunk lid when automatically closing, the trunk
lid opens again automatically. The automatic
obstruction detection with reversing feature is
only an aid. It is not a substitute for your atten-
tiveness when opening and closing the trunk lid. G WARNING
The reversing feature does not react: R
to soft, light and thin objects, e.g. small fin-
gers 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 sit-
uations. There is a risk of injury.
Make sure that no body parts are in close
proximity during the closing procedure.
If somebody becomes trapped: R
press the T button on the SmartKey, or R
pull or 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
Vehicles with HANDS-FREE ACCESS:
It is also possible to stop the closing process by
performing a kicking movement under the rear
bumper.
Opening and closing manually
Opening
X
Press the T button on the SmartKey.
or X
Pull handle C .
The trunk lid opens.90
Trunk
Opening and closing

Closing X
Pull the trunk lid down using recess C and
push it closed. X
Lock the vehicle if necessary with the 7
button on the SmartKey or with KEYLESS-GO
( Y
page 82).
Opening/closing automatically from
outside
Important safety notes
G WARNING
Parts of the body could become trapped dur-
ing automatic closing of the trunk lid. More-
over, 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 T button on the SmartKey.R
pull or 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.
Vehicles with HANDS-FREE ACCESS:
It is also possible to stop the closing process by
performing a kicking movement under the rear
bumper.
! The trunk lid swings upwards when opened.
Therefore, make sure that there is sufficient
clearance above the trunk lid.
The opening dimensions of the trunk lid can be
found in the "Vehicle data" section
( Y
page 394).
Opening automatically You can open the trunk lid automatically using
the SmartKey or the handle in the trunk lid. X
Press and hold the T button on the Smart-
Key until the trunk lid opens.
or X
If the trunk lid is unlocked, pull the trunk lid
handle and let it go again immediately.
Closing automatically
C
Closing button
D
Locking button X
Press closing button C in the trunk lid.Trunk 91
Opening and closing Z

Vehicles with trunk lid remote closing fea-
ture and KEYLESS-GO: when the driver's door
is closed you can simultaneously close the trunk
lid and lock the vehicle. The KEYLESS-GO key
must be in the rear detection range of the vehi-
cle. X
Press locking button D in the trunk lid.
If KEYLESS-GO detects a SmartKey outside
the vehicle, the trunk lid closes. The vehicle is
locked.
If KEYLESS-GO detects a SmartKey in the trunk,
the trunk lid opens again after it is closed.
If KEYLESS-GO detects a second SmartKey out-
side the vehicle, the trunk lid remains closed.
If KEYLESS-GO detects a SmartKey in the trunk
before the closing procedure starts, the trunk lid
remains open.
HANDS-FREE ACCESS
Important safety notes
G WARNING
The vehicle's exhaust system may be very hot.
You could burn yourself by touching the
exhaust system if you use HANDS-FREE
ACCESS. There is a risk of injury. Always
ensure that you only make the kicking move-
ment within the detection range of sensors.
! If the SmartKey is within the rear detection
range of KEYLESS-GO, the following situa-
tions, for example, could lead to the uninten-
tional opening of the trunk: R
using a car wash R
using a power washer
Make sure that the SmartKey is at least 10 ft
(3 m) away from the vehicle.
General notes With KEYLESS-GO and HANDS-FREE ACCESS,
you can open or close the trunk lid or stop the
procedure without using your hands. This is use-
ful if you have your hands full. To do this, make
a kicking movement under the bumper with your
foot. Observe the following points: R
Carry your KEYLESS-GO key about your per-
son. The KEYLESS-GO key must be in the rear
detection range of the vehicle. R
When making the kicking movement, make
sure that you are standing firmly on the
ground and that there is sufficient clearance
to the rear of the vehicle. You could otherwise
lose your balance e.g. on ice.
R
Always ensure that you only make the kicking
movement within the detection range of sen-
sors C . R
Stand at least 12 in (30 cm) away from the
rear area while doing so. R
Do not come into contact with the bumper
while making the kicking movement. Other-
wise, the sensors may not function correctly. R
HANDS-FREE ACCESS does not function
when the engine is started. R
Dirt caused by road salt around sensors C
may restrict functionality.
Using the HANDS-FREE ACCESS with a pros-
thetic leg may restrict functionality. R
If a KEYLESS-GO key is within the rear detec-
tion range of KEYLESS-GO, HANDS-FREE
ACCESS could be triggered. The trunk lid
could thus be opened or closed unintention-
ally, for example, if you: -
sit on the edge of the trunk. -
set something down or lift something up
behind the vehicle. -
polish the rear of the vehicle.
Do not carry the KEYLESS-GO key about your
person in these situations or in situations sim-
ilar to these. This will prevent the uninten-
tional opening/closing of the trunk.92
Trunk
Opening and closing