
Useful information
i This Owner's Manual describes all models,
series and optional equipment for your vehi-
cle that were available at the time of going to
press. National variations are possible. Note
that your vehicle may not be equipped with all
of the functions described. This is also the
case for systems and functions relevant to
safety.
i Read the information on qualified specialist
workshops: (Y page 25). Panic alarm
X
To prime: press the!button :for
approximately one second.
A visual and audible alarm is triggered if the
alarm system is primed.
X To deactivate: press the!button :
again.
or
X Insert the key into the ignition lock.
or, on vehicles with KEYLESS‑GO: X Press the Start/Stop button.
The key must be in the vehicle.
The panic alarm function is only available in cer- tain countries. Occupant safety
Introduction to the restraint system
The restraint system can reduce 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.
The restraint system comprises:
R Seat belt system
R Airbags
R Child restraint system
R Child seat securing systems
The components of the restraint system work in
conjunction with each other. They can only
deploy their protective function if all vehicle
occupants always:
R fasten their seat belts correctly
(Y page 40)
R adjust their seat and head restraint properly
(Y page 102).
As the driver, you also have to make sure that
the steering wheel is adjusted correctly.
Observe the information relating to the correct
driver's seat position (Y page 101).
You also have to make sure that an airbag can
inflate properly if deployed (Y page 42).
An airbag supplements a correctly fastened seat belt. As an additional safety device, the airbag
increases the level of protection for vehicle
occupants in the event of an accident. For exam-
ple, if the protection of the seat belt is sufficient in an accident, the airbags are not deployed. In
the event of an accident, only the airbags that
increase protection in the relevant accident sit- uation are deployed. However, seat belts and
airbags generally do not protect against objects penetrating the vehicle from the outside.
Information on the restraint system operation
can be found under "Triggering of belt tension-
ers and airbags" (Y page 49).
For more information about children travelling
with you in the vehicle, see "Children in the vehi-
cle" (Y page 52). Important safety notes
G
WARNING
If the restraint system is modified, it may no
longer work as intended. The restraint system
may then not perform its intended protective function by failing in an accident or triggering
unexpectedly, for example. There is an
increased risk of injury, possibly even fatal. Occupant safety
37Safety
Z 

seat belt, a windowbag may be deployed in other
accident situations (Y page 49).Automatic front-passenger front air-
bag deactivation
Introduction In order to recognise a child restraint system on
the front-passenger seat, the automatic front-
passenger front airbag deactivation system cat-
egorises the person in the front-passenger seat. Depending on that result, the front-passenger
front airbag is either enabled or disabled. If a
rearward-facing child restraint system is fitted
to the front-passenger seat, the PASSENGER
AIR BAG OFF indicator lamp must light up after
the system self-test and remain lit. The front-
passenger front airbag is disabled.
The system does not disable:
R the sidebag
R the windowbag
R the seat belt tensioner
In the following situation, the sidebag and the
seat belt tensioner are deactivated:
R the automatic front-passenger front airbag
deactivation system has not categorised the
person on the front-passenger seat as an
adult or a person of corresponding stature
and
R the seat belt tongue of the seat belt is not
inserted into the front-passenger seat belt
buckle
Make sure that your vehicle is equipped with the automatic front-passenger front airbag deacti-
vation system (Y page 56). If this is not the
case, always install a child restraint system on a suitable rear seat (Y page 57).
If it is absolutely necessary to install a child
restraint system on the front-passenger seat, be
sure to observe the correct positioning of the
child restraint system. Never place objects
under or behind the child restraint system, e.g. a
cushion. The entire base of the child restraint
system must always rest on the seat cushion of
the front-passenger seat. The backrest of the
forward-facing child restraint system must, as
far as possible, be resting on the backrest of the
front-passenger seat. The child restraint system must not touch the roof or be put under strain bythe head restraint. Adjust the angle of the seat
backrest and the head restraint position accord- ingly. Only then is the correct function of the
automatic front-passenger front airbag deacti-
vation system guaranteed. Always observe the
information on suitable positioning of the child
restraint system (Y
page 57) in addition to the
child restraint system manufacturer's installa-
tion instructions.
Operation of automatic front-passenger
front airbag deactivation :
PASSENGER AIR BAG ON indicator lamp
; PASSENGER AIR BAG OFF indicator lamp
The indicator lamps inform you whether the
front-passenger front airbag is disabled or ena-
bled. X Press the Start/Stop button once or twice, or
turn the key to position 1or 2in the ignition
lock.
The system carries out a self-diagnosis.
The PASSENGER AIR BAG OFF and PASSENGER AIR BAG ON indicator lamps must light up simul-
taneously for approximately six seconds.
The indicator lamps display the status of the
front-passenger front airbag:
R PASSENGER AIR BAG ON lights up: the front-
passenger front airbag is enabled. If, in the
event of an accident, all deployment criteria
are met, the front-passenger front airbag is
deployed.
R PASSENGER AIR BAG OFF lights up: the front-
passenger front airbag is disabled. It will then
not be deployed in the event of an accident.
If the status of the front-passenger front airbag
changes while the vehicle is in motion, an airbag display message appears in the instrument clus-
ter (Y page 264). When the front-passenger
seat is occupied, always pay attention to the
PASSENGER AIR BAG ON and PASSENGER AIR
BAG OFF indicator lamps. Be aware of the status Occupant safety
45Safety Z 

Display messages
Possible causes/consequences and
M
MSolutions Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
currently unavaila‐ currently unavaila‐
ble ble
See
SeeOwner's
Owner's Man‐
Man‐
ual
ual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R the radar sensor system is temporarily inoperative, e.g. due to elec-
tromagnetic radiation emitted by nearby TV or radio stations or
other sources of electromagnetic radiation
R the system is outside the operating temperature range
R The on-board voltage is too low.
Once the causes listed above no longer apply, the display message
goes out.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Safeguard the vehicle against rolling away (Y page 167).
X Restart the engine. Collision Preven‐ Collision Preven‐
tion Assist Plus tion Assist Plus
inoperative inoperative COLLISION PREVENTION ASSIST PLUS is temporarily inoperative due
to a malfunction. Adaptive Brake Assist may also have failed.
X Consult a qualified specialist workshop immediately. PRE-SAFE inopera‐
PRE-SAFE inopera‐
tive see Owner's tive see Owner's
Manual Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Consult a qualified specialist workshop immediately. PRE-SAFE Functions
PRE-SAFE Functions
currently limited currently limited
See Owner's Manual See Owner's Manual
PRE
‑SAFE ®
PLUS or PRE‑ SAFE®
Brake is temporarily inoperative.
Possible causes:
R the function is impaired due to heavy rain or snow
R the radar sensor system is temporarily inoperative, e.g. due to elec-
tromagnetic radiation emitted by nearby TV or radio stations or
other sources of electromagnetic radiation
R Mercedes-AMG vehicles: ESP ®
is deactivated
R the system is outside the operating temperature range
R The on-board voltage is too low.
Once the causes listed above no longer apply, the display message
goes out.
PRE ‑SAFE ®
PLUS and PRE ‑SAFE®
Brake are operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Safeguard the vehicle against rolling away (Y page 167).
X Restart the engine.
X Mercedes-AMG vehicles: reactivate ESP ®
(Y page 70). 260
Display
messagesOn-board computer and displays 

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions !
N
The red indicator lamp for the electric parking brake flashes or is lit and/or the
yellow warning lamp for the electric parking brake is lit.
X Observe the additional display messages in the multifunction display. 6
N
The red restraint system warning lamp is lit while the engine is running.
The restraint system is faulty.
G WARNING
The airbags or belt tensioners may either be triggered unintentionally or, in the
event of an accident, may not be triggered.
This poses an increased risk of injury.
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Contact a qualified specialist workshop immediately and have the restraint sys-
tem checked.
For further information about the restraint system, see (Y page 37).Engine
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ;
N
The yellow engine diagnostics warning lamp lights up while the engine is run-
ning.
There may be a fault, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engine may be running in
emergency mode.
X Consult a qualified specialist workshop immediately.
Vehicles with a diesel engine: the fuel tank has been run dry (Y page 164).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emergency running
mode is cancelled. The vehicle need not be checked. 8
N
The yellow reserve fuel warning lamp is on while the engine is running.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level drops into the
reserve range.
X Refuel at the nearest filling station. 294
Warning and indicator lamps in the instrument clusterOn-board computer and displays