MERCEDES-BENZ CLA 2023 Service Manual

Do not put your feet up on the cockpit, for
example. Your feet may otherwise be in the deployment area of the air bag.
= Fasten the seat belt correctly.
Notes on wearing the seat belt correctly
Always fasten your seat belt correctly before
starting a journey. A seat belt can provide the
best level of protection only if it is worn correctly.
&WARNING Risk of injury or death due to
incorrectly fastened seat belt
If the seat belt is not worn correctly, it cannot
perform its intended protective function.
In addition, an incorrectly fastened seat belt
can also cause injuries, for example, in the
event of an accident or when braking or
changing direction suddenly.
Always ensure that all vehicle occupants
have their seat belts fastened correctly
and are sitting properly.&WARNING Risk of injury or death when
additional restraint systems are not used
for persons with a smaller stature
Persons under 5 s (1.50 m ) tall cannot wear
the seat belt correctly without a suitable addi-
tional restraint system.
Always secure persons under 5 s
(1.50 m) tall in a suitable restraint sys-
tem.
Each vehicle occupant must observe the following
notes in particular:
= The seat belt must not be twisted:
= The shoulder belt strap must be routed
forward from the seat belt outlet over the cen- ter of your shoulder.
= The shoulder belt strap should neither touch
your neck nor be routed under your arm or
behind your back.
= The lap belt must be routed as low down
across the hips as possible.
In addition, push the lap belt down as far as
possible across your hips and pull tight with
the shoulder belt strap. Never route the lap
belt across your abdomen.
Pregnant women must also take particular
care with this.
= The shoulder belt strap and lap belt must Nt
snugly against the body aser being tightened.
= Avoid wearing bulky clothing, e.g. a winter
coat.
= Never route the seat belt across sharp, poin-
ted, abrasive or fragile objects.
= Only one person should use each seat belt at
any one time.
= Never secure objects with a seat belt if the
seat belt is also being used by one of the vehi-
cle\bs occupants.
Also ensure that no objects, e.g. a cushion, are ever placed between a person and theseat.
Fastening seat belts
If the seat belt is pulled quickly or sharply, theseat belt retractor locks. The seat belt strap can- not be pulled out any further.
Occupant safety39

Always engage seat belt tongue 2 of the seat
belt into seat belt buckle 1 of the corre-
sponding seat.*NOTE Deployment of components of the
restraint system when the front passenger
seat is unoccupied and a seat belt is
buckled
When the front passenger seat is unoccupied
and the seat belt tongue of the seat belt is
engaged in the seat belt buckle, components
of the restraint system may deploy unnecessa-
rily on the front passenger side, e.g. the Emer-
gency Tensioning Device.
Only buckle the seat belts as intended.\bObserve the information on the child seat
safety feature of the seat belt (  page 61).
Function of the restraint system warning lamp
When the vehicle is switched on, a self-test is per-
formed, during which the restraint system warning lamp u lights up. It goes out no later than a
few seconds aser the vehicle is started. The com-
ponents of the restraint system are then func-
tional.
A malfunction has occurred in the restraint sys-
tem if:
= the restraint system warning lamp u does
not light up when the vehicle is switched on
= the restraint system warning lamp u lights
up continuously or repeatedly during a journey
If components of the restraint system have been
deployed, the restraint system warning lamp u
lights up continuously.&WARNING Risk of injury due to malfunc-
tions in the restraint system
Components in the restraint system may be activated unintentionally or not deploy as plan-
ned in an accident.
Have the restraint system checked and
repaired immediately at a qualiNed spe-
cialist workshop.
Mercedes-Benz recommends that you have the
vehicle towed to a qualiNed specialist workshop.
40Occupant safety

Function of the seat belt warning lamp
The seat belt warning lamp

PASSENGER AIR BAG OFF is lit, no one may
use the front passenger seat.
If a rearward-facing child restraint system is installed on the front passenger seat,
PASSENGER AIR BAG OFF must be lit continu-
ously.
= Front passenger air bag enabled: PASSENGER
AIR BAG ON lights up for up to 60 seconds or
until both the PASSENGER AIR BAG ON and
OFF indicator lamps go out.
The front passenger air bag may be deployed during an accident. If the front passenger air
bag is in this status, no rearward-facing child
restraint system may be installed on the front
passenger seat.\bIf you are driving with a child in the vehicle, observe the information in the chapter "Chil-
dren in the vehicle" (  page 53)&WARNING Risk of injury or death due to a
disabled front passenger airbag
The front passenger airbag is disabled when
the PASSENGER AIR BAG OFF indicator lamp
is lit.
A person in the front passenger seat could
then, for example, come into contact with the
vehicle interior, especially if the person is sit-
ting too close to the cockpit.
If the front passenger seat is occupied, always ensure that:
= The classiNcation of the person in the front
passenger seat is correct and the front passenger airbag is enabled or disabled in
accordance with the person in the front
passenger seat.
= The front passenger seat has been moved
as far back as possible.
= The person is seated correctly.Both before and during the journey,
ensure that the status of the front
passenger airbag is correct.
Malfunction of the automatic front passenger air
bag shutoM
The PASSENGER AIR BAG OFF indicator lamp and
the u restraint system indicator lamp light up
simultaneously.
In this case, no one may use the front passenger seat and no child restraint system may be instal-
led on the front passenger seat.
Have the automatic front passenger air bag shut-
oM checked and repaired immediately at a quali-
Ned specialist workshop.
Be sure to also observe the following further rela-
ted subjects:
= Child restraint system on the front passenger
seat (  page 57)
Deactivating or activating the front passenger air
bag
The automatic front passenger air bag shutoM can
deactivate or activate the front passenger air bag
and front passenger knee bag according to the situation.
This happens automatically as a result of the clas-
siNcation of the person or child restraint system
on the front passenger seat.
You cannot manually deactivate or activate the front passenger air bag.
42Occupant safety

Also observe the following information:
= The status of the front passenger air bag, see
"Function of the PASSENGER AIR BAG indica-
tor lamps" (  page 41)
= Notes on using the front passenger seat, see
"Information on the automatic front passenger air bag shutoM ( page 43)
= If you are driving with a child in the vehicle,
observe the chapter "Children in the vehicle"
(  page 53)
Information on the child restraint system
When installing a child restraint system, observe
the notes in "Children in the vehicle"
(  page 53).
Notes on the child restraint system on the front passenger seat
&WARNING Risk of injury or fatal injuries if
the front passenger air bag is enabled
If the front passenger air bag is enabled, a
child on the front passenger seat may be
struck by the front passenger air bag in the
event of an accident.NEVER use a rearward-facing childrestraint system on a seat with an ENA-
BLED FRONT AIR BAG. This can result in
the DEATH of or SERIOUS INJURY to the CHILD.
Also pay particular attention to the notes on rear-
ward-facing or forward-facing child restraint sys- tems on the front passenger seat (  page 57).
Information on the automatic functions of the
restraint system
Function of the automatic front passenger air bag
shutoM
A person on the front passenger seat must
observe the following information:
= Sit correctly (  page 38).
= Fasten the seat belt correctly (  page 39).
The automatic front passenger air bag shutoM can
enable or disable the front passenger air bag and
the front passenger knee bag according to the sit- uation.
Make sure you observe the following information: = For the status of the front passenger air bag,
see "Function of the PASSENGER AIR BAG
indicator lamps" (  page 41)
= When installing a child restraint system on the
front passenger seat, observe the vehicle-spe- ciNc information (  page 57).
Status of the front passenger air bag in relation to
the stature of the person:
= Front passenger air bag disabled: PASSENGER
AIR BAG OFF lights up continuously.
The front passenger air bag will not be
deployed in the event of an accident. If
PASSENGER AIR BAG OFF is lit, no one may use the front passenger seat.
= Front passenger air bag enabled: PASSENGER
AIR BAG ON lights up for up to 60 seconds or
until both the PASSENGER AIR BAG ON and
OFF indicator lamps go out.
The front passenger air bag may be deployed
during an accident. Observe the followingOccupant safety43

information on the correct seat position
(  page 38).
Vehicles with rear seats: a person of smaller
stature should use a rear seat.
System limits
The front passenger air bag may otherwise be dis- abled by mistake, for example, in the following sit- uation:
= The front passenger transfers their weight by
supporting themselves on a vehicle armrest.
= The front passenger sits in such a way that
their weight is raised from the seat surface.*NOTE Deployment of components of the
restraint system when the front passenger
seat is unoccupied
In an accident, the components of the restraint system may deploy unnecessarily on
the front passenger side if:
= There are heavy objects on the front
passenger seat.
= The seat belt tongue is engaged in the seat
belt buckle of the front passenger seat and
the front passenger seat is unoccupied.Store objects in a suitable place.Only one person should use each seat
belt at any one time.
Depending on the detected accident situation, the window air bag on the front passenger side maydeploy. The air bag is deployed regardless of
whether the front passenger seat is occupied.
Function of PRE-SAFE n
(anticipatory occupant
protection)
PRE-SAFE n
is able to detect certain critical driv-
ing situations and implement pre-emptive meas-
ures to protect the vehicle occupants.
PRE-SAFE n
can implement the following meas-
ures independently of each other:
= Tightening the seat belts on the driver\bs seat
and front passenger seat.
= Closing the side windows.
=Vehicles with sliding sunroof: closing the slid-
ing sunroof.
= Vehicles with memory function: moving the
front passenger seat to a more favorable seat
position.
= PRE-SAFE n
Sound: provided that the multime-
dia system is switched on, generating a brief
noise signal to stimulate the innate protective mechanism of a person\bs hearing.*NOTE Damage caused by objects in the
footwell or behind the seat
The automatic adjustment of the seat position
may result in damage to the seat and/or the object.
Stow objects in a suitable place.
Backing up the PRE-SAFE n
system measures
If an accident did not occur, the pre-emptive
measures that were taken are reversed.
You will need to perform certain settings yourself.
44Occupant safety

If the seat belt pre-tensioning is not reduced,
move the seat backrest back slightly.
The locking mechanism releases.
Function of PRE-SAFE n
PLUS (anticipatory occu-
pant protection plus)
PRE-SAFE n
PLUS can detect certain impacts, par-
ticularly an imminent rear impact, and take pre-
emptive measures to protect the vehicle occu-
pants. These measures cannot necessarily pre-
vent an imminent impact.
PRE-SAFE n
PLUS can implement the following
measures independently of each other:
= Tightening the seat belts on the driver\bs seat
and front passenger seat.
= Increasing brake pressure when the vehicle is
stationary. This brake application is canceled
automatically when the vehicle pulls away.
If an accident did not occur, the pre-emptive
measures that were taken are reversed.
System limits
The system will not initiate any action in the fol- lowing situations:
= when backing up
The system will not initiate any braking application
in the following situations:
= whilst driving
or
= when entering or exiting a parking space while
using Active Parking Assist
Seat belt adjustment function
Vehicles with PRE-SAFE n
: aser you have fastened
the seat belt of the front seat, it may adjust itself
against your body by pulling at the shoulder until somewhat tight. Do not hold the seat belt tightlywhile it is adjusting.
This function is a reminder that all vehicle occu-
pants must wear their seat belts correctly.
You can activate and deactivate the seat belt
adjustment function using the multimedia system (  page 45).
Activating/deactivating seat belt adjustment via
the multimedia system
Multimedia system:
4 © 5
Settings 5
Vehicle
Activate or deactivate Belt Adjustment.
Overview of the automatic measures aser an acci-
dent
Depending on the type and severity of the acci-
dent, and depending on the vehicle\bs equipment, the following measures may be implemented, for
example:
= automatic braking (post-collision brake)
= activating the hazard warning lamps
= triggering an automatic emergency call
(  page 251)
= switching oM the engine
To start the vehicle again, switch the vehicle
oM and on once more (  page 133). Depend-
ing on the type and severity of the accident,
you may no longer be able to start the vehicle.
= switching oM the fuel supply
Occupant safety45

=unlocking the vehicle doors
= lowering the side windows
= displaying the emergency guide on the multi-
media system display
= switching on the interior lighting
Function of the post-collision brake aser an acci-
dent
Depending on the accident situation, the post-col-
lision brake can minimise the severity of a further
collision or even avoid it.
If an accident is detected, the post-collision brake can initiate automatic braking. When the vehiclehas come to a standstill, the electric parking
brake is automatically applied.
The driver can cancel automatic braking by taking
the following actions:
= Braking more strongly than automatic braking
= Fully depressing the accelerator pedal with
force
Purpose and function of the restraint system
Overview of deployment situations (restraint sys- tem)
Make sure that the following prerequisites in par-
ticular have been met so that the components of the restraint system are able to provide the inten-ded level of protection:
= Sit correctly (  page 38).
= Fasten the seat belt correctly (  page 39).
- Function of the seat belt warning lamp
(  page 41).
= The u restraint system warning lamp is not
lit up aser the self-test (  page 40).
= The PASSENGER AIR BAG indicator lamps dis-
play the correct status of the front passenger air bag (  page 41).
Depending on the detected deployment situation, the components of the restraint system can beactivated or deployed independently of each
other:
= Emergency Tensioning Device: frontal impact,
rear impact, side impact, rollover
= Driver\bs air bag, front passenger air bag: fron-
tal impact
= Knee bag: frontal impact
= Side impact air bag: side impact
= Window curtain air bag: side impact, rollover,
frontal impact
The installation location of an air bag is identiNed
by the AIRBAG symbol (  page 52).
Observe the information on the function of the
restraint system (  page 46).
Information on how the restraint system works
How the restraint system functions depends on
the severity of the impact detected and the appa- rent type of accident.
For more information about types of accidents, see "Overview of deployment situations"
(  page 46).
The activation thresholds for the components of
the restraint system are determined based on the
evaluation of the sensor values measured at vari-
ous points in the vehicle. This process is pre-emp-
46Occupant safety

tive in nature. The triggering/deployment of the
components of the restraint system must take place in good time at the start of the collision.
Factors that can be seen and measured only aser
a collision has occurred cannot play a decisive role in air bag deployment. Nor do they provide an indication of air bag deployment.
The vehicle may be deformed signiNcantly without
an air bag being deployed. This is the case if only parts that are relatively easily deformed are aMec-
ted and the rate of vehicle deceleration is not
high. Conversely, an air bag may be deployed
even though the vehicle suMers only minor defor-
mation. If very rigid vehicle parts such as longitu- dinal members are hit, this may result in suP-
ciently high levels of vehicle deceleration.
Depending on the apparent type of accident and
the detected deployment situation, Emergency
Tensioning Devices and/or air bags supplement
the protection oMered by a correctly worn seat
belt.
When enabled, an air bag can provide additional
protection for the respective vehicle occupant.Potential protection provided by each air bag:
= Knee bag: thigh, knee and lower leg
= Driver\bs air bag, front passenger air bag: head
and ribcage
= Window curtain air bag: head
= Side impact air bag: ribcage and pelvis*NOTE Mercedes-AMG vehiclesObserve the notes in the Supplement.
You could otherwise fail to recognize
dangers.
However, no system available today can com-
pletely eliminate injuries and fatalities in every
accident situation. In particular, the seat belt and
air bag generally do not protect against objects penetrating the vehicle from the outside. It is alsonot possible to completely rule out the risk ofinjury caused by the air bag deploying.
Mercedes-Benz recommends that you have the
vehicle towed to a qualiNed specialist workshop
aser an accident. Take this into account, particu-
larly if a Emergency Tensioning Device is triggered
or an air bag deployed.
If the Emergency Tensioning Devices are triggered
or an air bag is deployed, you will hear a bang,
and a small amount of powder may also be released:
= The bang will not generally aMect your hearing.
= In general, the powder released is not hazard-
ous to health but may cause short-term breathing diPculties to persons suMering from
asthma or other pulmonary conditions.
Provided it is safe to do so, leave the vehicle
immediately or open the window in order to
prevent breathing diPculties.
Air bags and pyrotechnic Emergency Tensioning
Devices contain perchlorate material, which may require special handling or environmental protec-
tion measures. National guidelines regarding waste disposal must be observed. In California,
see https://dtsc.ca.gov/. Using the search func- tion, you will Nnd information on perchlorate, for
example.Occupant safety47

Information on the limited protection provided bythe restraint system
Risk due to the incorrect behavior of vehicle occu-
pants
Every vehicle occupant must make sure of the fol- lowing in particular:
= They observe the information on the correct
seat position (  page 38).
= There are no heavy, sharp-edged or fragile
objects in the pockets of their clothing. Store
such objects in a suitable place.
&WARNING Risk of injury or death due to
an incorrect seat position
The seat belt does not oMer the intended level
of protection if you have not moved the seat backrest to an almost vertical position.
In particular, you could slip beneath the seat- belt and become injured.
Adjust the seat properly before begin-
ning your journey.Always ensure that the seat backrest is
in an almost vertical position and thatthe shoulder belt is routed across the center of your shoulder.
Risk due to objects in the vehicle interior
Every vehicle occupant must make sure of the fol-
lowing in particular:
= They observe the information on the correct
seat position (  page 38).
= There are no objects between the seat, door
and door pillar (B-pillar).
= There are no hard objects, e.g. coat hangers,
hanging on the grab handles or coat hooks.
= There are no heavy, sharp-edged or fragile
objects in the pockets of their clothing. Store
such objects in a suitable place.
&WARNING Risk of injury or death due to
blocked seat belt buckle or seat belt
anchorage
Objects next to the front seat that block the seat belt buckle or the moving seat belt
anchorage on the front seat impair the func- tion of the Emergency Tensioning Devices.
Before starting the journey, make sure
that there are no objects around the seat
belt buckle or between the front seat
and door.&WARNING Risk of injury from objects in
the deployment area of an airbag
Objects in the deployment area of an airbag
can hinder or prevent the correct deployment
of the airbag.
The airbag may then deploy in an uncontrolled manner and may even cause additional inju-
ries to the vehicle occupants by deploying.
This may be the case in particular if the airbag is integrated into the seat.
Always stow and secure objects cor-
rectly.Before commencing your journey, make
sure that no objects are stowed in the
deployment area of an airbag.
The installation location of an air bag is identiNed
by the AIRBAG (  page 52) symbol.
48Occupant safety