
G
WARNING
If the housing of the high-voltage battery has
been damaged, electrolyte and gases may
leak out. These are poisonous and caustic.
There is a risk of injury.
Avoid contact with the skin, eyes or clothing. Immediately rinse electrolyte splashes off
with water and seek medical attention
straight away.
! Exhaustive discharge caused by the vehi-
cle standing idle for lengthy periods can
damage the high-voltage battery.
If the vehicle is idle for lengthy periods, run
it for a few minutes once every six weeks to
charge up the high-voltage battery.
During the charging process, switch off all
electrical consumers, e.g. the automatic
climate control or the seat heating.
Information on charging the high-voltage bat-
tery (Y page 416).
Engine compartment Before opening the bonnet:
X Apply the electric parking brake.
X Shift the automatic transmission to park
position P.
X Switch the ignition off.
X Remove the key from the ignition lock.
or, in vehicles with KEYLESS-GO start-func-
tion or KEYLESS ‑GO
X Remove the Start/Stop button from the
ignition lock.
X Observe the warning notes on the risk of
electric shock (Y page 42).
X Observe the warning notes about the bon-
net (Y page 391). RBS driving safety system (Recupera-
tive Brake System)
RBS supports you when braking with an elec-
tronically-controlled brake boost mode and enables the recovery of kinetic energy (recu-
peration).
For further information on the RBS system
(Y page 269). Panic alarm
X
To activate: press!button :for
approximately one second.
An alarm sounds and the exterior lighting
flashes.
X To deactivate: press!button :
again.
or
X Insert the key into the ignition lock.
or, in vehicles with KEYLESS-GO start-func-
tion or KEYLESS ‑GO
X Press the Start/Stop button.
The key must be in the vehicle.
The panic alarm function is only available in
certain countries. Occupant safety
Introduction to the restraint system
The restraint system reduces the risk of vehi- cle occupants coming into contact with parts
of the vehicle's interior in the event of an
accident. The restraint system can also
reduce the forces to which vehicle occupants
are subjected during an accident. 44
Occupant safetySafety

R
when the external door handles are
touched
R during convenience closing X
To unlock the vehicle: touch the inner
surface of the door handle.
X To lock the vehicle: touch sensor sur-
face :or;.
Make sure that you do not touch the inner
surface of the door handle.
X Convenience closing feature: touch
recessed sensor surface ;for an exten-
ded period.
For further information on the convenience closing feature (Y page 107).
X To unlock the boot lid: pull the boot lid
handle.
Deactivating If you do not intend to use the vehicle for a
longer period of time, you can deactivate KEY- LESS-GO. The key will then use very little
power, thereby conserving battery power. For
the purposes of activation/deactivation, the
vehicle must not be nearby.
X To deactivate: press the&button on
the key twice in rapid succession.
The battery check lamp of the key lights up
twice briefly and KEYLESS-GO is deactiva-
ted.
X To activate: press any button on the key or
insert the key into the ignition lock.
KEYLESS-GO and all of its associated fea-
tures are available again. KEYLESS-GO start function
Bear in mind that the engine can be started by any of the vehicle occupants if there is a key
in the vehicle. 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 alone.
X To change the setting: press and hold
down the %and& buttons simulta-
neously for about six seconds until the bat- tery indicator lamp flashes twice
(Y page 94).
If the setting of the locking system is changed
within the signal range of the vehicle, press-
ing the &or% button:
R locks or
R unlocks the vehicle
The key now functions as follows:
X To unlock the driver's door: press the
% button once.
X To unlock centrally: press the%but-
ton twice.
X To lock centrally: press the&button.
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 door handle on the front-
passenger door or the rear door.
X To lock centrally: touch the outer sensor
surface on one of the door handles.
X To restore the factory settings: press
and hold down the %and& buttons
simultaneously for approximately six sec- 92
KeyOpening and closing

onds until the battery check lamp flashes
twice (Y
page 94). Emergency key element
General notes If the vehicle can no longer be locked or
unlocked with the key or KEYLESS-GO, use
the emergency key element.
If you use the emergency key element to
unlock and open the driver's door, the anti-
theft alarm system will be triggered. Switch
off the alarm (Y page 85).
If you unlock the vehicle using the emergency
key element, the fuel filler flap will not be
unlocked automatically.
X To unlock the fuel filler flap: insert the
key into the ignition lock.
Removing the emergency key element X
Push release catch :in the direction of
the arrow and at the same time, remove
emergency key element ;from the key.
Further information about: R unlocking the driver's door (Y page 98)
R unlocking the boot (Y page 105)
R locking the vehicle (Y page 100)
Inserting the emergency key element X
Push emergency key element ;com-
pletely into the key until it engages and release catch
:is back in its basic posi-
tion. Battery of the key
Important safety notes 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. H
Environmental note Batteries contain pollutants.
It is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in anenvironmentally responsible
recycling system. Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-
lection point for used batter-
ies.
Mercedes-Benz recommends that you have
the batteries replaced at a qualified specialist workshop. Key
93Opening and closing Z

Checking the battery
X
Press the &or% button.
The battery is working properly if battery
check lamp :lights up briefly.
The battery is discharged if battery check
lamp :does not light up briefly.
X Replace the battery (Y page 94).
If the key battery is checked within the signal reception range of the vehicle, pressing the
& or% button:
R locks or
R unlocks the vehicle
i You can obtain a battery from any quali-
fied specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X Take the emergency key element out of the
key (Y page 93). X
Press emergency key element ;into the
opening in the key in the direction of the
arrow until battery compartment cover :opens. When doing so, do not hold battery
compartment cover
:shut.
X Remove battery compartment cover :. X
Repeatedly tap the key against your palm
until battery =falls out.
X Insert the new battery with the positive ter-
minal facing upwards. Use a lint-free cloth
to do so.
X Make sure that the surface of the battery is
free of lint, grease and other contamina-
tion.
X Insert the front tabs of battery compart-
ment cover :into the housing and then
press to close it.
X Insert emergency key element ;into the
key.
X Check the function of all key buttons on the
vehicle. 94
KeyOpening and closing

Problems with the key
Problem
Possible causes/consequences and
M
MSolutions You can no longer lock
or unlock the vehicle
using the key. The key battery is discharged or nearly discharged.
X Check the key battery (Y page 94) and replace it if necessary
(Y page 94).
If this does not work: X Unlock (Y page 98) or lock (Y page 100) the vehicle using the
emergency key element. There is interference from a powerful source of radio waves.
X Unlock (Y page 98) or lock (Y page 100) the vehicle using the
emergency key element. The key is faulty.
X Unlock (Y page 98) or lock (Y page 100) the vehicle using the
emergency key element.
X Have the key 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 91). The key battery is discharged or nearly discharged.
X Check the key battery (Y page 94) and replace it if necessary
(Y page 94).
If this does not work: X Unlock (Y page 98) or lock (Y page 100) the vehicle using the
emergency key element. There is interference from a powerful source of radio waves.
X Unlock (Y page 98) or lock (Y page 100) the vehicle using the
emergency key element. There is a fault with KEYLESS-GO.
X Lock/unlock the vehicle using the remote control function of
the key.
X Have the vehicle and key checked at a qualified specialist work-
shop.
If the vehicle can also not be locked/unlocked using the remote
control function:
X Unlock (Y page 98) or lock (Y page 100) the vehicle using the
emergency key element.
X Have the vehicle and key checked at a qualified specialist work-
shop. Key
95Opening and closing Z

Problem
Possible causes/consequences and
M
MSolutions The engine cannot be
started using the 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 416).
or
X Jump-start the vehicle (Y page 418).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the Start/
Stop button. The key is
in the vehicle. The vehicle is locked.
X Unlock the vehicle and try to start the vehicle again. The key battery is discharged or nearly discharged.
X Check the key battery (Y page 94) and replace it if necessary
(Y page 94).
If this does not work: X Start your vehicle with the key in the ignition lock. There is interference from a powerful source of radio waves.
X Start your vehicle with the key in the ignition lock. You have lost a key. X
Have the key 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 emer-
gency key element. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. Doors
Important safety notes
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside. People in the vehicle can no longer get out, e.g. in hazardous situations. There is a
risk of injury. Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld- erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked from the out-
side, the double-lock function is activated as
standard. It is then not possible to open the
doors from inside the vehicle. You can deac-
tivate the double lock function by deactivat-
ing the interior motion sensor (Y page 86).96
DoorsOpening and closing

X
Release the rear seat backrest and fold it
slightly forwards (Y page 372).
X To remove: pull the head restraint up to
the stop.
X Press release catch :and pull the head
restraint out of the guides.
X To refit: insert the head restraint so that
the notches on the bar are on the left when
viewed in the direction of travel.
X Push the head restraint down until you hear
it engage in position.
X Fold back the rear seat backrest until it
engages. Adjusting the 4-way lumbar support
:
To raise the backrest contour
; To soften the backrest contour
= To lower the backrest contour
? To harden the backrest contour
You can adjust the contour of the front seat
backrests individually to provide optimum
support for your back. Switching the seat heating on/off
Activating/deactivating G
WARNING
If you repeatedly switch on seat heating, the
seat cushion and backrest padding may
become very hot. The health of vehicle occu-
pants with limited temperature sensitivity or a limited ability to react to excessively high temperatures may be affected or they may
even suffer burn-like injuries. There is a risk of
injury.
Therefore, do not switch on the seat heating
repeatedly. The three red indicator lamps in the button
indicate the heating level you have selected.
The system automatically switches from level
3 to level 2after approximately eight
minutes.
The system automatically switches from level 2 to level 1after approximately ten minutes.
The system automatically switches off
approximately 20 minutes after it is set to
level 1.
X Turn the key to position 1or 2in the ignition
lock (Y page 181).
X To switch on: press button:repeatedly
until the desired heating level is set.
X To switch off: press button:repeatedly
until all the indicator lamps go out.
i If the battery voltage is too low, the seat
heating may switch off.
i If drive program Eis selected, the power
of the seat heating is reduced.
R Manual transmission (Y page 192)
R Automatic transmission (Y page 197) Seats
123Seats, ste ering wheel and mirrors Z

Problems with the seat heating
Problem
Possible causes/consequences and
M
MSolutions The seat heating has
switched off prema-
turely or cannot be
switched on. The on-board voltage is too low because too many electrical con-
sumers are switched on.
X Switch off electrical consumers that you do not need, such as
the rear window heating or interior lighting.
Once the battery is sufficiently charged, the seat heating can be
switched back on manually. Switching the seat ventilation on/off
Activating/deactivating The three blue indicator lamps in the buttons
indicate the ventilation level you have selec-
ted.
X Turn the key to position 1or 2in the ignition
lock (Y page 181).
X To switch on: press button:repeatedly
until the desired ventilation level is set.
X To switch off: press button:repeatedly
until all the indicator lamps go out.
i If the battery voltage is too low, the seat
ventilation may switch off.
i You can open the side windows and the
sliding sunroof using the "Convenience
opening" feature (Y page 107). The seat
ventilation of the driver's seat automati-
cally switches to the highest level.
i When the vehicle is stationary, the fan
speed can be reduced automatically. This
reduces the noises of the seat ventilation. 124
SeatsSeats, steering wheel and mirrors