
the vehicle's high-voltage electrical system
checked by a qualified specialist workshop.
The components of the vehicle's high-voltage
electrical system are marked with yellow warn-
ing stickers. The cables of the vehicle's high-
voltage electrical system are orange in color.
Vehicles with an electric motor generate much
less driving noise than vehicles with internal
combustion engines. As a result, your vehicle
may not be heard by other road users in certain
situations. This can happen, for example, when
you are parking and your vehicle is not seen by
other road users. This requires you to adopt a
particularly anticipatory driving style, as it is
necessary to allow for the possibility that other
road users may behave erratically.
Declarations of conformity
Vehicle components which receive
and/or transmit radio waves USA: "The wireless devices of this vehicle com-
ply with Part 15 of the FCC Rules. Operation is
subject to the two following two conditions: 1)
These devices may not cause harmful interfer-
ence, and 2) These devices must accept any
interference received, including interference
that may cause undesired operation. Changes
or modifications not expressly approved by the
party responsible for compliance could void the
user’s authority to operate the equipment."
Canada: "The wireless devices of this vehicle
comply with Industry Canada license-exempt
RSS standard(s). Operation is subject to the fol-
lowing two conditions: (1) These devices may
not cause interference, and (2) These devices
must accept any interference, including inter-
ference that may cause undesired operation of
the device."
Diagnostics connection
The diagnostics connection is only intended for
the connection of diagnostic equipment at a
qualified specialist workshop.
G WARNING
If you connect equipment to the diagnostics
connection in the vehicle, it may affect the operation of the vehicle systems. As a result,
the operating safety of the vehicle could be
affected. There is a risk of an accident.
Do not connect any equipment to a diagnos-
tics connection in the vehicle.
G WARNING
Objects in the driver's footwell can restrict the
pedal travel or obstruct a depressed pedal.
The operating and road safety of the vehicle is
jeopardized. There is a risk of an accident.
Make sure that all objects in the vehicle are
stowed correctly, and that they cannot enter
the driver's footwell. Install the floormats
securely and as specified in order to ensure
sufficient clearance for the pedals. Do not use
loose floormats and do not place floormats on
top of one another.
! If the engine is switched off and equipment
on the diagnostics connection is used, the
starter battery may discharge.
Connecting equipment to the diagnostics con-
nection can lead to emissions monitoring infor-
mation being reset, for example. This may lead
to the vehicle failing to meet the requirements of
the next emissions test during the main inspec-
tion.
Qualified specialist workshop An authorized Mercedes-Benz Center is a quali-
fied specialist workshop. It has the necessary
specialist knowledge, tools and qualifications to
correctly carry out the work required on your
vehicle. This is especially the case for work rel-
evant to safety.
Observe the notes in the Maintenance Booklet.
Always have the following work carried out at an
authorized Mercedes-Benz Center: R
work relevant to safety R
service and maintenance work R
repair work R
alterations, installation work and modifica-
tions R
work on electronic components R
work on the hybrid drive systemOperating safety 31
Introduction Z

X
If possible, move the vehicle out of the
danger zone: shift the transmission into posi-
tion N .X
Release the electric parking brake. X
Roll the vehicle to a safe place and park it
safely.
Get assistance from others if necessary.
The vehicle is locked automatically when the
ignition is switched on and the wheels are turn-
ing. There is therefore a risk of being locked out
if the vehicle is being pushed or tested on a
dynamometer. X
Switch the ignition off. X
Shift the transmission to position P .
Depress the electric parking brake
( Y
page 178).
Secure the vehicle against rolling away
( Y
page 380). X
To use the high-voltage switch-off device:
open the hood.
X
Press release clip C in the direction of the
arrow and pull it out. X
Pull the high voltage switch-off device D
apart until it engages in the stop position.
If the hybrid drive system has been deactivated
due to reasons mentioned above, have it
checked at a qualified specialist workshop
before reactivation.
High-voltage battery
G WARNING
In the event of a vehicle fire, the internal pres-
sure of the high-voltage battery can exceed a
critical value. In this case flammable gas
escapes through a ventilation valve on the underbody. The gas can ignite. There is a risk
of injury.
Leave the danger zone immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements.
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 skin, eyes or clothing.
Immediately rinse electrolyte splashes off
with water and seek medical attention
straight away.
PLUG-IN HYBRID vehicles: charging the high-
voltage battery ( Y
page 168).
Engine compartment Before opening the hood: X
Apply the electric parking brake. X
Shift the transmission to position P .X
Switch the ignition off. X
Remove the SmartKey from the ignition lock.
or, in vehicles with KEYLESS-GO start-function
or KEYLESS ‑ GO X
Remove the Start/Stop button from the igni-
tion lock. X
Observe the warning notes on the risk of elec-
tric shock ( Y
page 44). X
Observe the warning notices about the hood
( Y
page 330).
RBS driving safety system (Recupera-
tive Brake System) The Recuperative Brake System supports you
when braking with an electronically-controlled
brake boost mode and enables the recovery of
kinetic energy (recuperation).
Further information about the Recuperative
Brake System ( Y
page 225).Hybrid vehicles 45
Safety Z

This steering assistance is provided in particular
if: R
both right wheels or both left wheels are on a
wet or slippery road surface when you brake. R
the vehicle starts to skid.
Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 68).
No steering support is provided from STEER
CONTROL, if: R
ESP ®
is deactivatedR
ESP ®
is malfunctioning.R
the lighting is faulty.
If ESP ®
is malfunctioning, you will be assisted
further by the electrical power steering.
Protection against theft
Immobilizer The immobilizer prevents your vehicle from
being started without the correct SmartKey. X
To activate with the SmartKey: remove the
SmartKey from the ignition lock. X
To activate with KEYLESS-GO start-func-
tion or KEYLESS-GO: switch the ignition off
and open the driver's door. X
To deactivate: switch on the ignition.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Anyone
can start the engine if a valid SmartKey has been
left inside the vehicle.
i The immobilizer is always deactivated when
you start the engine.
In the event that the engine cannot be started
(yet the vehicle's battery is charged), the sys-
tem is not operational. Contact an authorized
Mercedes-Benz Center or call
1-800-FOR-MERCedes (in the USA) or
1-800-387-0100 (in Canada). ATA (anti-theft alarm system) X
To arm: lock the vehicle with the SmartKey or
KEYLESS-GO.
Indicator lamp C flashes. The alarm system
is armed after approximately 10 seconds. X
To disarm: unlock the vehicle with the Smart-
Key or KEYLESS-GO.
or X
Insert the SmartKey into the ignition lock.
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 X
To turn the alarm off with the SmartKey:
press the 6 or 7 button on the Smart-
Key.
The alarm is switched off.
or X
Vehicles with KEYLESS-GO start-function
or KEYLESS-GO: remove the Start/Stop but-
ton from the ignition lock ( Y
page 146).X
Insert the SmartKey into the ignition lock.
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 dash-
board. The SmartKey must be inside the vehi-
cle.
The alarm is switched off.
The alarm is not switched off, even if you close
the open door that triggered it, for example.Protection against theft 79
Safety Z

You will receive visual and acoustic locking con-
firmation if all components were able to be
locked.
When the locator lighting is activated via the
multimedia system, it lights up when it is dark
after the vehicle is unlocked with the SmartKey
(see the Digital Operator's Manual). X
To open the trunk lid automatically from
outside the vehicle: press and hold the T
button until the trunk lid opens. X
To open the trunk lid automatically from
outside the vehicle: if the SmartKey is loca-
ted in the immediate vicinity of the vehicle,
press the T button on the SmartKey.
When the trunk lid closes you can then
release the button.
KEYLESS-GO
General notes Bear in mind that the engine can be started by
any of the vehicle occupants if there is a Smart-
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 func-
tions of KEYLESS-GO with those of a conven-
tional SmartKey. Unlock the vehicle by using
KEYLESS-GO, for instance, and lock it using the
7 button on the SmartKey.
The driver's door and the door at which the han-
dle is used, must both be closed. The SmartKey
must be outside the vehicle. 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).
A brief radio connection between the vehicle
and the key determines whether a valid Smart-
Key is in, or in the direct vicinity of, the vehicle.
This occurs, for example: R
when starting the engine R
while driving R
when using HANDS-FREE ACCESS R
when the external door handles are touched R
during convenience closing X
To unlock the vehicle: touch the inner sur-
face of the door handle. X
To lock the vehicle: touch sensor surface C
or D .
Make sure that you do not touch the inner
surface of the door handle. X
Convenience closing feature: touch
recessed sensor surface D for an extended
period.
Further information on the convenience clos-
ing feature ( Y
page 96). X
To unlock the trunk lid: pull the handle on
the trunk lid.
Deactivating and activating If you do not intend to use a key for an extended
period of time, you can deactivate the KEYLESS-
GO function of the SmartKey. The SmartKey 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 7 button on the
SmartKey twice in rapid succession.
The battery check lamp of the SmartKey
flashes twice briefly and lights up once, then
KEYLESS-GO is deactivated ( Y
page 84).X
To activate: press any button on the Smart-
Key.
or X
Insert the SmartKey into the ignition lock.
KEYLESS-GO and all of its associated features
are available again.82
SmartKey
Opening and closing

KEYLESS- GO start function
Gene ra l notesBear in min d that th e engin e can be started by
any of th e vehicl e occupant s if there is a Smart -
Key in th e vehicle.
Changing the settings of the locking
system You can chang e th e setting s of th e locking sys-
tem. This mean s that only th e driver's door and
th e fuel filler flap are unlocke d when th e vehicl e
is unlocked. This is useful if you frequentl y travel
on your own .X
To change th e setting: press and hold down
th e 6 and 7 buttons simultaneousl y
for approximately six seconds until th e bat -
tery chec k lamp flashes twice ( Y
page 84).
If th e setting of th e locking system is changed
within th e signal range of th e vehicle, pressing
th e 7 or 6 button:R
locks or R
unlocks th e vehicl e
The SmartKey no w function s as follows :X
To unlock: press th e 6 butto n once .X
To unlock centrally: press th e 6 butto n
twice .X
To lock: press th e 7 button.
The KEYLESS-GO function s can be changed as
follows :X
To unlock th e driver's door : touch th e inner
surfac e of th e door handle on th e driver's
door .X
To unlock centrally: touch th e inner surfac e
of th e door handle on th e front-passenger
door or th e rear door .X
To lock centrally: touch th e outer sensor
surfac e on on e of th e door handles .X
To restor e th e factory settings: press and
hold th e 6 and 7 buttons simulta ne -
o
usl y for approximately six seconds until th e
battery chec k lamp flashes twice
( Y
page 84) . Mechanical key
Gene ra l notesIf th e vehicl e can no longer be locke d or
unlocke d wit h th e SmartKey or KEYLESS-GO ,
use th e mechanical key.
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) .
If you unloc k th e vehicl e usin g th e mechanical
key, th e fuel filler flap will no t be unlocke d auto -
matically. X
To unlock th e fuel filler flap: insert th e
SmartKey int o th e ignition lock.
Removing the me chanical key
X
Push release catch C in th e direction of th e
arrow and at th e sam e time remove mechan -
ical ke y D from th e SmartKey.
Further information : R
Unlocking th e driver's door ( Y
page 89 )R
Locking th e vehicl e ( Y
page 89 )
Inserting the me chanical key X
Push mechanical ke y D completely int o th e
SmartKey until it engage s and release
catch C is bac k in it s basic position .SmartKey 83
Opening and closing Z

SmartKey battery
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 dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
and recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National guide-
lines must be observed during disposal. In Cal-
ifornia, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/index.cfm .
Mercedes-Benz recommends that you have the
batteries replaced at a qualified specialist work-
shop. Checking the battery X
Press the 7 or 6 button.
The battery is working properly if battery
check lamp C lights up briefly.
The battery is discharged if battery check
lamp C does not light up briefly. X
Change the battery ( Y
page 84).
If the SmartKey battery is checked within the
signal reception range of the vehicle, pressing
the 7 or 6 button: R
locks or R
unlocks the vehicle
i You can get a battery at any qualified spe-
cialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery. X
Take the mechanical key out of the SmartKey
( Y
page 83).
X
Press mechanical key D into the SmartKey
opening in the direction of the arrow until bat-
tery compartment cover C opens. Do not
hold battery compartment cover C closed
while doing so. X
Remove battery compartment cover C .84
SmartKey
Opening and closing