MERCEDES-BENZ GLS 2023 Service Manual

Restraint system functionality
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.
Malfunctioning restraint system
A malfunction has occurred in the restraint sys-
tem if:
= The u restraint system warning lamp does
not light up when the vehicle is switched on
= The u restraint system warning lamp lights
up continuously or repeatedly during a journey
&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.
Function of the restraint system in an accident
How the restraint system works depends on the
severity of the impact detected and the apparent type of accident:
= Frontal impact
= Rear impact
= Side impact
= Rollover
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-
tive in nature. The restraint system components must be triggered/deployed in good time at the
start of the collision.
Factors that can only be seen or measured 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 have been
deployed even though the vehicle has suMered
only minor deformation. If very rigid vehicle parts
such as longitudinal members are hit, for exam-
ple, this may result in suPciently high levels of
vehicle deceleration.
Depending on the detected deployment situation, the components of the restraint system can beactivated or deployed independently of one
another:
= Emergency Tensioning Device: frontal impact,
rear impact, side impact, rollover
= Driver\bs air bag, front passenger air bag: fron-
tal impact
= Knee air bag: frontal impact
= Side air bag: side impact
= Window air bag: side impact, rollover, frontal
impactOccupant safety39

=Cushion air bag: frontal impact
= PRE-SAFE n
Impulse Side: side impact
The front passenger air bag can only be deployed in an accident if the PASSENGER AIR BAG OFFindicator lamp is oM. If the front passenger seat is
occupied, make sure, both before and during the journey, that the status of the front passenger air
bag is correct (  page 49).&WARNING Risk of burns from hot air bag
components
The air bag parts are hot aser an air bag has
been deployed.
Do not touch the air bag parts.Have a deployed air bag replaced at a
qualiNed specialist workshop as soon as
possible.Mercedes-Benz recommends that you have the
vehicle towed to a qualiNed specialist workshop
aser an accident. Take this into account espe-
cially if a Emergency Tensioning Device was trig-
gered or an air bag was 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 the https://dtsc.ca.gov/. Using the search function, you will Nnd information on perchlorate,
for example.Seat belts
Protection provided by the seat belt
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.
Always observe the instructions about the correct
driver\bs seat position and adjusting the seat (  page 98).
40Occupant safety

In order for the correctly worn seat belt to provide
the intended level of protection, each vehicle
occupant must observe the following information:
= The seat belt must not be twisted and must Nt
tightly and snugly across the body.
= The seat belt must be routed across the cen-
ter of the shoulder and as low down acrossthe hips as possible.
= The shoulder section of the seat belt should
not touch your neck nor be routed under your arm or behind your back.
= Avoid wearing bulky clothing, e.g. a winter
coat.
= Push the lap belt down as far as possible
across your hips and pull tight with the shoul- der section of the belt. Never route the lap
belt across your abdomen.
Pregnant women must also take particular
care with this.
= 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.
The seat belts on the following seats are equipped with a special seat belt retractor:
= Front passenger seat
= Rear passenger compartment seats
Activate or deactivate the special seat belt retrac-
tor of the seat belt (  page 58).
If children are traveling in the vehicle, be sure to observe the instructions and safety notes on
"Children in the vehicle" (  page 54).
Always observe the instructions for loading the vehicle when securing objects, luggage or loads
(  page 125).Limitations of the protection provided by the seat
belt&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 that
the shoulder belt is routed across the
center of your shoulder.&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.
Occupant safety41

Always secure persons under 5 s
(1.50 m) tall in a suitable restraint sys-
tem.&WARNING Danger of injury or death due
to blocked seat belt anchorage
The restraint eMect of the seat belt is impaired
if objects between the front seat and the door
are blocking the movable seat belt anchorage
on the front seat.
Before starting a journey, make sure that
there are no objects between the front
seat and the door.&WARNING Risk of injury or death due to
damaged or modiNed seat belts
Seat belts cannot provide protection in the fol-
lowing situations:
= The seat belt is damaged, has been modi-
Ned, is extremely dirty, bleached or dyed
=
The seat belt buckle is damaged or
extremely dirty
= ModiNcations have been made to the
Emergency Tensioning Device, seat belt
anchorage or seat belt retractor
Seat belts may sustain non-visible damage in
an accident, e.g. due to glass splinters.
ModiNed or damaged seat belts could tear or
fail in the event of an accident, for example.
ModiNed Emergency Tensioning Devices could
accidentally trigger or fail to function as inten- ded.Never modify the seat belt system, for
example the seat belt, seat belt buckle,
Emergency Tensioning Device, seat belt
anchorage and seat belt retractor.Make sure that the seat belts are undam-
aged, not worn and clean.Always have the seat belts checked immediately aser an accident at a quali-
Ned specialist workshop.Only use seat belts which have been approved for
your vehicle by Mercedes-Benz.&WARNING Risk of injury or death from
deployed pyrotechnic Emergency Tension-
ing Devices
Pyrotechnic Emergency Tensioning Devices that have been deployed are no longer opera-
tional and are unable to perform their inten-
ded protective function.
Therefore, have deployed pyrotechnic
Emergency Tensioning Devices immedi-
ately replaced at a qualiNed specialist
workshop.
Mercedes-Benz recommends that you have the
vehicle towed to a qualiNed specialist workshop
aser an accident.
*NOTE Damage caused by trapping the
seat belt
If an unused seat belt is not fully retracted, it
may become trapped in the door or in the seat
mechanism.
42Occupant safety

Always ensure that an unused seat belt
is fully retracted.
Fastening and adjusting seat belts
If the seat belt is pulled quickly or sharply, the seat belt retractor locks. The seat belt strap can-
not be pulled out any further.
Always engage seat belt tongue 1 of the seat
belt into seat belt buckle 2 of the corre-
sponding seat.To adjust the seat belt height: press button 3
on the seat belt outlet and slide the seat belt outlet to the desired position.To engage the seat belt outlet: release button
3 and ensure that the seat belt outlet
engages.\bA seat belt can only provide the best level of
protection if it is worn correctly. Observe the notes on fastening the seat belt (  page 40).*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 notes on stowage areas
(  page 125).
Information on installing a child restraint sys- tem and on children traveling in the vehicle
can be found in the "Children in the vehicle"
section (  page 57).
Seat belt adjustment function
Vehicles with PRE-SAFE n
: aser a front seat belt
has been fastened, the automatic seat belt adjust-
ment may apply a certain amount of tightening
force. Do not hold the seat belt tightly while it is
adjusting.
You can activate and deactivate the seat belt
adjustment function using the multimedia system (  page 44).
Occupant safety43

Activating/deactivating seat belt adjustment viathe multimedia system
Multimedia system:
4 © 5
Settings 5
Vehicle
Activate or deactivate Belt Adjustment.
Releasing seat belts
Press the release button in the seat belt
buckle and guide the seat belt back with the
seat belt tongue.
Seat belt warning function for the driver and front passenger
The

Potential protection provided by each air bag:
= Knee air 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&WARNING Risk of injury or death if the co-
driver airbag is enabled
If the co-driver airbag is enabled, a child on
the co-driver seat may be struck by the co-
driver airbag during an accident.
NEVER use a rearward-facing child restraint
system on a seat with an ENABLED FRONT
AIRBAG; DEATH or SERIOUS INJURY to the
CHILD can occur.
When Ntting a child restraint system to the front
passenger seat, observe the vehicle-speciNc infor-
mation (  page 66). Also, always observe the
notes on rearward-facing or forward-facing child
restraint systems on the front passenger seat (  page 66).
Information on automatic front passenger air bag
shutoM
The front passenger air bag can be deployed in an accident only if the PASSENGER AIR BAG OFFindicator lamp is oM. If the front passenger seat is
occupied, make sure !

&WARNING Risk of injury or death due to
an incorrect seat position
If you deviate from the correct seat position,
the airbag cannot perform its intended protec-
tive function.
Each vehicle occupant must make sure of the
following:
= Fasten seat belts correctly. Pregnant
women must take particular care to ensure
that the lap belt never lies across the
abdomen.
= Adopt the correct seat position and keep
as far away as possible from the airbags.
= Observe the following information.
Always make sure that there are no
objects between the airbag and vehicle
occupant.To avoid the risks resulting from the deployment
of an airbag, each vehicle occupant must observe
the following information in particular:
= Before starting your journey, adjust your seat
correctly; the driver\bs seat and frontpassenger seat should be moved as far back as possible.
When doing so, always observe the informa-
tion on the correct driver\bs seat position
(  page 98).
= Only hold the steering wheel by the steering
wheel rim. This allows the airbag to be fully
deployed.
= Always lean against the seat backrest when
the vehicle is in motion. Do not lean forwards
or against the door or side window. You may otherwise be in the deployment area of the
airbags.
= The occupants must always keep their feet on
the Ooor. Do not put your feet on the cockpit,
for example. Your feet may otherwise be in the
deployment area of the airbag.
= If children are traveling in the vehicle, observe
the additional notes (  page 54).
= Always stow and secure objects correctly.Objects in the vehicle interior may prevent an air-
bag from functioning correctly. Each vehicle occu-
pant must always make sure of the following in
particular:
= There are no people, animals or objects
between the vehicle occupants and an airbag.
= 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 accessories, such as mobile navi-
gation devices, mobile phones or cup holders,
within the deployment area of an airbag, e.g.on the cockpit, on the door, on the side win-
dow or on the side trim.
In addition, no connecting cables, tensioning straps or retaining straps must be routed or
attached to the vehicle within the deployment
area of an airbag. Always comply with the
accessory manufacturer\bs installation instruc-
tions and, in particular, the notes on suitable
places for installation.46Occupant safety

=There are no heavy, sharp-edged or fragile
objects in the pockets of your clothing. Store
such objects in a suitable place.
Limitations of the protection provided by airbags
&WARNING Risk of injury due to modiNca-
tions to the cover of an airbag
If you change the cover of an airbag or attach
objects, e.g. even stickers, to it, the airbag may no longer function as intended.
Never modify the cover of an airbag.Do not attach any objects to the cover.
The installation location of an airbag is identiNed
by the AIRBAG symbol (  page 44).
Objects in the deployment area of an airbag may prevent the airbag from functioning correctly.
&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.&WARNING Risk of injury or death due to
the use of unsuitable seat covers
Due to unsuitable seat covers, the airbags
cannot protect vehicle occupants as intended.
In addition, the operation of the automatic
front passenger airbag shutoM could be
restricted.
You should only use seat covers that
have been approved for the correspond-
ing seats by Mercedes-Benz.&WARNING Risk of injury due to malfunc-
tioning sensors in the door
The function of the airbags can be impaired
due to modiNcations or incorrect work per-
formed on the doors or door trim, or if the
doors are damaged.
Never modify the doors or parts of the
doors.Always have work on the doors or door
trim carried out at a qualiNed specialist
workshop.&WARNING Risk of injury due to deployed
airbag
A deployed airbag no longer oMers any protec-
tion.
Occupant safety47

Have the vehicle towed to a qualiNed
specialist workshop in order to have the
deployed airbag replaced.Have deployed airbags replaced immediately.
Status of the front passenger front airbag
Function of the automatic front passenger air bag
shutoM
The automatic front passenger air bag shutoM is
able to detect whether the front passenger seat is
occupied by a person or a child restraint system. The front passenger air bag is enabled or disabled
accordingly.
&WARNING Risk of injury or death due to
objects under the co-driver seat
Objects trapped under the co-driver seat can
interfere with the function of the automatic
co-driver airbag shutoM or damage the system.
Do not store any objects under the co-
driver seat.When the co-driver seat is occupied,make sure that no objects are trapped
under the co-driver seat.
When Ntting a child restraint system to the front
passenger seat, observe the vehicle-speciNc infor-
mation (  page 66). Also, always observe the
notes on rearward-facing or forward-facing child
restraint systems on the front passenger seat
(  page 66).
A person on the front passenger seat must observe the following information:
= Fasten seat belts correctly (  page 40).
= Sit in an almost upright seat position with their
back against the seat backrest.
= Sit with their feet resting on the Ooor, if possi-
ble.
The front passenger air bag may otherwise be dis-
abled by mistake, for example, in the following sit- uations:
= 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.&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.
48Occupant safety