2018 MERCEDES-BENZ CLS ECU

driver or front passenger have fastened their
seat belts.
If the driver or front passenger unfasten their
seat belts during the journey, the seat belt warn-
ing is activated again.
Air bags
Introduction The installation point of an air bag can be rec-
ognized by the AIR BAG symbol.
An air bag complements the correctly fastened
seat belt. It is no substitute for the seat belt. The
air bag provides additional protection in appli-
cable accident situations.
Not all air bags are deployed in an accident. The
different air bag systems function independ-
ently from one another ( Y
page 53).
However, no system available today can com-
pletely eliminate injuries and fatalities.
It is also not possible to rule out a risk of injury
caused by an air bag due to the high speed at
which the air bag must be deployed.
Important safety notes
G WARNING
If you do not sit in the correct seat position,
the air bag cannot protect as intended and
could even cause additional injury when
deployed. This poses an increased risk of
injury or even fatal injury.
To avoid hazardous situations, always make
sure that all of the vehicle's occupants: R
have fastened their seat belts correctly,
including pregnant women R
are sitting correctly and maintain the great-
est possible distance to the air bags R
follow the following instructions
Always make sure that there are no objects
between the air bag and the vehicle's occu-
pants. R
Adjust the seats properly before beginning
your journey. Always make sure that the seat
is in an almost upright position. The center of the head restraint must support the head at
about eye level. R
Move the driver's and front-passenger seats
as far back as possible. The driver's seat posi-
tion must allow the vehicle to be driven safely. R
Only hold the steering wheel on the outside.
This allows the air bag to be fully deployed. R
Always lean against the backrest while driv-
ing. Do not lean forwards or lean against the
door or side window. You may otherwise be in
the deployment area of the air bags. R
Always keep your feet in the footwell in front
of the seat. Do not put your feet on the dash-
board, for example. Your feet may otherwise
be in the deployment area of the air bag. R
For this reason, always secure persons less
than 5 ft (1.50 m) tall in suitable restraint sys-
tems. Up to this height, the seat belt cannot
be worn correctly.
If a child is traveling in your vehicle, also
observe the following notes: R
Always secure children under twelve years of
age and less than 5 ft (1.50 m) tall in suitable
child restraint systems. R
Child restraint systems should be installed on
the rear seats. R
Only secure a child in a rearward-facing child
re straint system on the front-passenger seat
when the front-passenger front air bag is
deactivated. If the PASSENGER AIR BAG OFF
indicator lamp is permanently lit, the front-
passenger front air bag is deactivated
( Y
page 42). R
Always observe the instructions and safety
notes on the "Occupant Classification System
(OCS)" ( Y
page 49) and on "Children in the
vehicle" ( Y
page 58 )i n addition to the child
restraint system manufacturer's installation
and operating instructions.
Objects in the vehicle interior may prevent
an air bag from functioning correctly. Before
starting your journey and to avoid risks resulting
from the speed of the air bag as it deploys, make
sure that: R
there are no people, animals or objects
between the vehicle occupants and an air
bag. R
there are no objects between the seat, door
and B-pillar. R
no hard objects, e.g. coat hangers, hang on
the grab handles or coat hooks.46
Occupant safety
Safety

PASSENGER AIR BAG OFF indicator lamp C
shows you whether the front-passenger front air
bag is deactivated. X
Turn the SmartKey to position 1 or 2 in the
ignition lock or on vehicles with KEYLESS-GO,
press the Start/Stop button once or twice.
The system carries out self-diagnostics.
The PASSENGER AIR BAG OFF indicator lamp
must light up for approximately six seconds.
The PASSENGER AIR BAG OFF indicator lamp
then displays the status of the front-passenger
front air bag. If the status of the front-passenger
front air bag changes while the vehicle is in
motion, an air bag display message may appear
in the instrument cluster ( Y
page 210). When
the front-passenger seat is occupied, always
pay attention to the PASSENGER AIR BAG OFF
indicator lamp. Be aware of the status of the
front-passenger front air bag both before and
during the journey.
If the PASSENGER AIR BAG OFF indicator
lamp: R
is lit : the front-passenger front air bag is
deactivated. It will then not be deployed in the
event of an accident. R
is not lit : the front-passenger front air bag is
enabled. If, in the event of an accident, all
deployment criteria are met, the front-
passenger front air bag is deployed.
G WARNING
If the PASSENGER AIR BAG OFF indicator
lamp is lit, the front-passenger front air bag is
disabled. It will not be deployed in the event of
an accident and cannot perform its intended
protective function. A person in the front-
passenger seat could then, for example, come
into contact with the vehicle's interior, espe-
cially if the person is sitting too close to the
dashboard. This poses an increased risk of
injury or even fatal injury.
When the front-passenger seat is occupied,
always ensure that: R
the classification of the person in the front-
passenger seat is correct and the front-
passenger front air bag is enabled or disa- bled in accordance with the person in the
front-passenger seat R
the front-passenger seat has been moved
back as far back as possible. R
the person is seated correctly.
Make sure, both before and during the jour-
ney, that the status of the front-passenger
front air bag is correct.
G WARNING
If you secure a child in a child restraint system
on the front-passenger seat and the
PASSENGER AIR BAG OFF indicator lamp is
off, the front-passenger front air bag can
deploy in the event of an accident. The child
could be struck by the air bag. This poses an
increased risk of injury or even fatal injury.
Make sure that the front-passenger front air
bag has been disabled. The PASSENGER AIR
BAG OFF indicator lamp must be lit.
G WARNING
If you secure a child in a forward-facing child
restraint system on the front-passenger seat
and you position the front-passenger seat too
close to the dashboard, the child could, in the
event of an accident: R
come into contact with the vehicle's inte-
rior if the PASSENGER AIR BAG OFF indi-
cator lamp is lit, for example R
be struck by the air bag if the PASSENGER
AIR BAG OFF indicator lamp is off
This poses an increased risk of injury or even
fatal injury.
Move the front-passenger seat as far back as
possible. Always make sure that the shoulder
belt strap is correctly routed from the vehicle
belt sash guide to the shoulder belt guide on
the child restraint system. The shoulder belt
strap must be routed forwards and down-
wards from the vehicle belt sash guide. If nec-
essary, adjust the vehicle belt sash guide and
the front-passenger seat accordingly. Always
observe the child restraint system manufac-
turer's installation instructions.50
Occupant safety
Safety

Aut oma tic measures after an acci-
dent Immediately after an accident, th e followin g
measures are implemented, depending on th e
typ e and severity of th e impact :R
th e hazard warning lamp s are activatedR
th e emergenc y lighting is activatedR
th e vehicl e door s are unlocke dR
th e fron t side windows are loweredR
vehicles wit h a memory function : th e electri-
call y adjustable steering whee l is raisedR
th e engin e is switched off and th e fuel supply
is cut off R
vehicles wit h mbrace : automatic emergenc y
call
Children in the vehicle
Import ant safety notesAcciden t statistics sho w that children secured
in th e rear seat s are safer than children secured
in th e front-passenger seat . Fo r this reason ,
Mercedes-Benz strongly advises that you instal l
a child restrain t system on a rear seat . Children
are generally bette r protected there .
If a child younger than twelve years old and
under 5 ft (1.5 0 m) in height is traveling in the
vehicle: R
always secure the child in a child restraint
system suitable for Mercedes-Benz vehicles.
The child restraint system must be appropri-
ate to the age, weight and size of the child R
be sure to observe the instructions and safety
notes in this section in addition to the child
restraint system manufacturer's installation
instructions R
be sure to observe the instructions and safety
notes on the "Occupant classification system
(OCS)" ( Y
page 49)
G WARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example: R
release the parking brake. R
shift the automatic transmission out of the
parking position P .R
start the engine. In addition, they may operate vehicle equip-
ment and become trapped. 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 unsupervised in the vehicle.
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
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro-
tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in
the vehicle.
Always ensure that all vehicle occupants have
their seat belts fastened correctly and are sitting
properly. Particular attention must be paid to
children.
Observe the safety notes on the seat belt
( Y
page 43) and the notes on correct use of seat
belts ( Y
page 44).
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lbs (18 kg) until they reach a height where a
three-point seat belt can be properly fastened
without a booster seat.
Special seat belt retractor
G WARNING
If the seat belt is released while driving, the
child restraint system will no longer be58
Children in the vehicle
Safety

secured properly. The special seat belt retrac-
tor is disabled and the inertia real draws in a
portion of the seat belt. The seat belt cannot
be immediately refastened. There is an
increased risk of injury, possibly even fatal.
Stop the vehicle immediately, paying atten-
tion to road and traffic conditions. Reactivate
the special seat belt retractor and secure the
child restraint system properly.
All seat belts except the driver's seat belt are
equipped with a special seat belt retractor.
When activated, the special seat belt retractor
ensures that the seat belt will not slacken once
the child restraint system has been secured.
Installing a child restraint system: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Pull the seat belt smoothly from the belt out-
let. X
Engage the seat belt tongue in the belt buckle.
Activating the special seat belt retractor: X
Pull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should
hear a ratcheting sound. The special seat belt
retractor is activated. X
Push the child seat restraint system down so
that the seat belt is tight and does not loosen.
Removing a child restraint system and deacti-
vating the special seat belt retractor: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Press the release button of the belt buckle,
hold the belt tongue firmly and guide it back
towards the belt outlet.
The special seat belt retractor is deactivated.
Child restraint system
The use of seat belts and child restraint systems
is required by law in: R
all 50 states R
the U.S. territories R
the District of Columbia R
all Canadian provinces You can obtain further information about the
correct child restraint system from any author-
ized Mercedes-Benz Center.
G WARNING
If the child restraint system is installed incor-
rectly on a suitable seat, it cannot protect as
intended. The child cannot then be restrained
in the event of an accident, heavy braking or
sudden changes of direction. There is an
increased risk of injury, possibly even fatal.
Make sure that you observe the child restraint
system manufacturer's installation instruc-
tions and the notes on use. Please ensure,
that the base of the child restraint system is
always resting completely on the seat cush-
ion. Never place objects, e.g. cushions, under
or behind the child restraint system. Only use
child restraint systems with the original cover
designed for them. Only replace damaged
covers with genuine covers.
G WARNING
If the child restraint system is installed incor-
rectly or is not secured, it can come loose in
the event of an accident, heavy braking or a
sudden change in direction. The child
restraint system could be thrown about, strik-
ing vehicle occupants. There is an increased
risk of injury, possibly even fatal.
Always install child restraint systems prop-
erly, even if they are not being used. Make
sure that you observe the child restraint sys-
tem manufacturer's installation instructions.
You will find further information on stowing
objects, luggage or loads under "Loading guide-
lines" ( Y
page 242).
G WARNING
Child restraint systems or their securing sys-
tems which have been damaged or subjected
to a load in an accident can no longer protect
as intended. The child cannot then be
restrained in the event of an accident, heavy
braking or sudden changes of direction. There
is an increased risk of injury, possibly even
fatal.Children in the vehicle 59
Safety Z

Replac e child restrain t systems whic h hav e
been damaged or subjecte d to a load in an
acciden t as soo n as possible. Hav e th e secur-
ing systems on th e child restrain t system
checke d at a qualified specialist workshop,
before you instal l a child restrain t system
again .
The securin g systems of child restrain t systems
are: R
th e seat belt systemR
th e LATCH-type (ISOFIX) securin g ringsR
th e Top Tether anchorages
If it is absolutely necessar y to carry a child on
th e front-passenger seat , be sur e to observ e th e
information on th e "Occupant Classification
Syste m (OCS)" ( Y
page 49). There you will also
fin d information on deactivating th e front-
passenger fron t air bag.
All child restrain t systems mus t mee t th e fol -
lowin g standards :R
U.S. Federal Motor Vehicl e Safet y Standards
21 3 and 22 5R
Canadian Motor Vehicl e Safet y Standards
21 3 and 210. 2
Confirmation that th e child restrain t system cor-
responds to th e standards can be foun d on an
instruction label on th e child restrain t system.
This confirmation can also be foun d in th e instal -
lation instruction s that are included wit h th e
child restrain t system.
Observ e th e warning labels in th e vehicl e inte-
rio r and on th e ch ild re strain t s
ystem.
LATCH-type (ISOFIX) child seat secur-
ing system
G WARNIN G
LATCH-type (ISOFIX) child restrain t systems
do no t offer sufficien t protective effec t for
children whos e weigh t is greate r than 48 lbs
(22 kg ) who are secured usin g th e safet y belt
integrate d in th e child restrain t system. In th e
event of an accident, a child might no t be
restrained correctly. This poses an increased
ris k of injury or eve n fatal injury.
If th e child weigh s mor e than 48 lbs (22 kg),
only use LATCH-type (ISOFIX) child restrain t systems wit h whic h th e child is also secured
wit h th e vehicl e seat belt . Als o secure th e
child restrain t system wit h th e Top Tether
belt , if available.
Always comply wit h th e manufacturer' s instal -
lation and operating instruction s for th e child
restrain t system used .
Before every trip, mak e sur e that th e LATCH -
typ e (ISOFIX) child restrain t system is engage d
correctl y in bot h LATCH-type (ISOFIX) securin g
rings
When installin g th e LATCH-type (ISOFIX) child
restrain t system, fol d protective cap s D of
securin g rings C inwards .X
Install th e LATCH-type (ISOFIX) child restrain t
system on bot h LATCH-type (ISOFIX) securin g
rings C .
ISOFIX is a standardize d securin g system for
specially designed child restrain t systems on
th e rear seats. LATCH-type (ISOFIX) securin g
rings for two LATCH-type (ISOFIX) child restrain t
systems are installed on th e lef t and right of th e
rear seats.
Non-LATCH-typ e (ISOFIX) child seat s may also
be used and can be installed usin g th e vehicle's
seat belt system. Install th e child seat according
to th e manufacturer' s instructions.
Top Tether
Introduction
Top Tether provide s an additional connection
between th e child restrain t system secured wit h
a LATCH-type (ISOFIX) system and th e vehicle.
This help s reduce th e ris k of injury eve n further.
If th e child restrain t system is equipped wit h a
Top Tether belt , this should always be used .60
Children in the vehicle
Safety

G WARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro-
tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in
the vehicle.
Child-proof locks for the rear doors
You secure each door individually with the child-
proof locks on the rear doors. A door secured
with a child-proof lock cannot be opened from
inside the vehicle. When the vehicle is unlocked,
the door can be opened from the outside. X
To activate: press the child-proof lock lever
up in the direction of arrow C .X
Make sure that the child-proof locks are work-
ing properly. X
To deactivate: press the child-proof lock
lever down in the direction of arrow D . Override feature for the rear side win-
dows X
To activate/deactivate: press button D .
If indicator lamp C is lit, operation of the rear
side windows is disabled. Operation is only
possible using the switches in the driver's
door. If indicator lamp C is off, operation is
possible using the switches in the rear com-
partment.
Pets in the vehicle
G WARNING
If you leave animals unattended or unsecured
in the vehicle, they could press buttons or
switches, for example.
As a result, they could: R
activate vehicle equipment and become
trapped, for example R
activate or deactivate systems, thereby
endangering other road users
Unsecured animals could also be flung around
the vehicle in the event of an accident or sud-
den steering or braking, thereby injuring vehi-
cle occupants. There is a risk of an accident
and injury.
Never leave animals unattended in the vehi-
cle. Always secure animals properly during
the journey, e.g. use a suitable animal trans-
port box.Pets in the vehicle 63
Safety Z

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 284).
or X
Jump-start the vehicle ( Y
page 285).
or X
Consult a qualified specialist workshop.
The engine cannot be
started using KEYLESS-
GO. The SmartKey is in
the vehicle. The vehicle is locked. X
Unlock the vehicle 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.
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 PR
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.
Unlocking and opening doors from
the inside You can open a door from inside the vehicle
even if it has been locked.
If the vehicle has previously been locked from
the outside, opening a door from the inside will
trigger the anti-theft alarm system. Switch off
the alarm ( Y
page 75).
You can only open the rear doors from inside the
vehicle if they are not secured by the child-proof
locks ( Y
page 63). Doors 81
Opening and closing Z

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 up locking knob
on the rear door.
The rear door is unlocked and can be opened. X
To open a rear door: pull the rear door han-
dle.
Centrally locking and unlocking the
vehicle from the inside You can centrally lock or 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 .
If all the doors are closed, the vehicle locks.
Meanwhile, the fuel filler flap will not be locked
or unlocked.
If the vehicle has been locked from the outside,
it cannot be centrally unlocked 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 63).
If a locked door is opened from the inside, the
previous unlock status of the vehicle will be
taken into consideration if: R
the vehicle was locked using the locking but-
ton for the central locking, or R
if the vehicle was 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.
Automatic locking feature
X
To deactivate: press and hold button C for
about five seconds until a tone sounds. X
To activate: press and hold button D for
about five seconds until a tone sounds.
If you press one of the two buttons and do not
hear a tone, the relevant setting has already
been selected.
The vehicle is locked automatically when the
ignition is switched on and the wheels are turn-
ing.
You could therefore lock yourself out if: R
the vehicle is being pushed. R
the vehicle is being towed. R
the vehicle is on a roller dynamometer.
You can also switch the automatic locking func-
tion on and off using the on-board computer
( Y
page 199).82
Doors
Opening and closing