MERCEDES-BENZ GLS 2017 Service Manual

Overhead control panel
Function Page
C
= Switches the left-hand
reading lamp on/off
116
D
J Switches the front inte-
rior lighting on
116

Door contro l panel
Function Page
C
Opens th e doo r 80
D
67 Unlocks/locks
the vehicle
80

Panic alarm X
To activate: press 3 button C for at least
one second.
A visual and audible alarm is triggered if the
alarm system is armed. X
To deactivate: press 3 button C again.
or X
Insert the SmartKey into the ignition lock.
or X
Press the KEYLESS-GO Start/Stop button.
The KEYLESS-GO key must be in the vehicle.
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
air bags 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, at all times, all
vehicle occupants: R
have fastened their seat belts correctly
( Y
page 44) R
have adjusted their seat and head restraint
properly ( Y
page 94). 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 94).
You also have to make sure that an air bag can
inflate properly if deployed ( Y
page 46).
An air bag supplements a correctly worn seat
belt. As an additional safety device, the air bag
increases the level of protection for vehicle
occupants in the event of an accident. For exam-
ple, if, in the event of an accident, the protection
offered by the seat belt is sufficient, the air bags
are not deployed. When an accident occurs, only
the air bags that increase protection in that par-
ticular accident situation are deployed. How-
ever, seat belts and air bags generally do not
protect against objects penetrating the vehicle
from the outside.
Information on restraint system operation can
be found under "Triggering of the Emergency
Tensioning Devices and air bags" ( Y
page 53).
For information on children traveling with you in
the vehicle and on child restraint systems, see
"Children in the vehicle" ( Y
page 57).
Important safety notes
G WARNING
Modifications to the restraint system may
cause it to no longer work as intended. The
restraint system may then not perform its
intended protective function and may fail in an
accident or trigger unexpectedly, for example.
This poses an increased risk of injury or even
fatal injury.
Never modify parts of the restraint system.
Never tamper with the wiring, the electronic
components or their software.
If it is necessary to modify components of the
restraint system to accommodate a person
with disabilities, contact an authorized
Mercedes-Benz Center for details. USA only:
for further information contact our Customer
Assistance Center at 1-800-FOR-MERCedes
(1 ‑ 800 ‑ 367 ‑ 6372).
Mercedes-Benz recommends that you only use
driving aids which have been approved specifi-
cally for your vehicle by Mercedes-Benz.Occupant safety 41
Safety Z

Restraint system warning lamp The functions of the restraint system are
checked after the ignition is switched on and at
regular intervals while the engine is running.
Therefore, malfunctions can be detected in
good time.
The u restraint system warning lamp in the
instrument cluster lights up when the ignition is
switched on. It goes out no later than a few sec-
onds after the vehicle is started. The compo-
nents of the restraint system are in operational
readiness.
A malfunction has occurred if the u restraint
system warning lamp: R
does not light up after the ignition is switched
on R
does not go out after a few seconds with the
engine running R
lights up again while the engine is running
G WARNING
If the restraint system is malfunctioning,
restraint system components may be trig-
gered unintentionally or may not deploy as
intended during an accident. This can affect
for example the Emergency Tensioning
Device or the air bag. This poses an increased
risk of injury or even fatal injury.
Have the restraint system checked and
repaired in a qualified specialist workshop as
soon as possible.
PASSENGER AIR BAG indicator lamp
PASSENGER AIR BAG ON indicator lamp C and
PASSENGER AIR BAG OFF indicator lamp D are
part of the Occupant Classification System
(OCS). The indicator lamps display the status of the
front-passenger front air bag. R
PASSENGER AIR BAG ON lights up for 60 sec-
onds, subsequently both indicator lamps are
off (PASSENGER AIR BAG ON and OFF): the
front-passenger front air bag is able to deploy
in the event of an accident. R
PASSENGER AIR BAG OFF lights up: the front-
passenger front air bag is deactivated. It will
then not be deployed in the event of an acci-
dent.
If the PASSENGER AIR BAG ON indicator lamp is
off, only the PASSENGER AIR BAG OFF indicator
lamp shows the status of the front-passenger
front air bag. The PASSENGER AIR BAG OFF
indicator lamp may be lit continuously or be off.
Depending on the person in the front-passenger
seat, the front-passenger front air bag must
either be deactivated or enabled; see the fol-
lowing points. You must make sure of this both
before and during a journey. R
Children in a child restraint system:
whether the front-passenger front air bag is
enabled or deactivated depends on the instal-
led child restraint system, and the age and
size of the child. Therefore, be sure to observe
the notes on the "Occupant Classification
System (OCS)" ( Y
page 48) and on "Chil-
dren in the vehicle" ( Y
page 57). There you
w ill also find instructions on rearward and
forward-facing child restraint systems on the
front-passenger seat. R
All other persons: depending on the classi-
fication of the person in the front-passenger
seat, the front-passenger front air bag is ena-
bled or deactivated ( Y
page 48). Be sure to
observe the notes on "Seat
belts“ ( Y
page 42) and "Air bags"
( Y
page 46). There you can also find infor-
mation on the correct seat position.
Seat belts
Introduction
Seat belts are the most effective means of
restricting the movement of vehicle occupants
in the event of an accident or the vehicle rolling
over. This reduces the risk of vehicle occupants
coming into contact with parts of the vehicle
interior or being ejected from the vehicle. Fur-
thermore, the seat belt helps to keep the vehicle42
Occupant safety
Safety

occupant in the best position in relation to the
air bag.
The seat belt system comprises: R
Seat belts R
Emergency Tensioning Devices for the front
seat belts and the outer seat belts in the sec-
ond row of seats as well as the seat belts in
the third row R
Seat belt force limiters for the front seat belts
and the outer seat belts in the second row of
seats as well as the seat belts in the third row
If the seat belt is pulled out of the belt outlet
quickly or with a jerky movement, the belt
retractor locks. The belt strap cannot be extrac-
ted any further.
The Emergency Tensioning Device tightens the
seat belt in an accident, pulling the belt close
against the body. However it does not pull the
vehicle occupant back in the direction of the
backrest.
The Emergency Tensioning Device does not cor-
rect an incorrect seat position or the routing of
an incorrectly fastened seat belt.
When triggered, a seat belt force limiter helps to
reduce the force exerted by the seat belt on the
vehicle occupant.
The seat belt force limiters for the front seats are
synchronized with the front air bags, which
absorb part of the deceleration force. This can
reduce the force exerted on the vehicle occu-
pants during an accident.
! If the front-passenger seat is unoccupied,
do not insert the belt tongue into the buckle of
the front-passenger seat. This may otherwise
lead to the triggering of the Emergency Ten-
sioning Device in the event of an accident,
which will then need to be replaced.
Important safety notes 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
Even where this is not required by law, all vehicle
occupants should correctly fasten their seat
belts before starting the journey. G WARNING
If the seat belt is not worn correctly, it cannot
perform its intended protective function. An
incorrectly fastened seat belt can also cause
injuries, for example, in the event of an acci-
dent or when braking or changing direction
abruptly. This poses an increased risk of injury
or even fatal injury.
Always ensure that all vehicle occupants have
their seat belts fastened correctly and are sit-
ting properly.
G WARNING
The seat belt does not offer the intended level
of protection if you have not moved the back-
rest to an almost vertical position. When brak-
ing or in the event of an accident, you could
slide underneath the seat belt and sustain
abdomen or neck injuries, for example. This
poses an increased risk of injury or even fatal
injury.
Adjust the seat properly before beginning
your journey. Always ensure that the backrest
is in an almost vertical position and that the
shoulder section of your seat belt is routed
across the center of your shoulder.
G WARNING
Persons less than 5 ft (1.50 m) tall cannot
wear the seat belt correctly without an addi-
tional and suitable restraint system. If the
seat belt is not worn correctly, it cannot per-
form its intended protective function. An
incorrectly fastened seat belt can also cause
injuries, for example, in the event of an acci-
dent or when braking or changing direction
abruptly. This poses an increased risk of injury
or even fatal injury.
For this reason, always secure persons under
5 ft (1.50 m) tall in suitable additional restraint
systems.
If a child younger than twelve years old and
under 5 ft (1.50 m) in height is traveling in the
vehicle: R
always secure the child in a child restraint
system suitable for this Mercedes-Benz vehi-Occupant safety 43
Safety Z

cle. The child restraint system must be appro-
priate to the age, weight and size of the child R
always observe the instructions and safety
notes on "Children in the vehicle"
( Y
page 57) in addition to the child restraint
system manufacturer's installation and oper-
ating instructions R
be sure to observe the instructions and safety
notes on the "Occupant classification system
(OCS)" ( Y
page 48)
G WARNING
The seat belts may not perform their intended
protective function if: R
they are damaged, modified, extremely
dirty, bleached or dyed R
the seat belt buckle is damaged or
extremely dirty R
the Emergency Tensioning Devices, belt
anchorages or inertia reels have been modi-
fied.
Seat belts may be damaged in an accident,
although the damage may not be visible, e.g.
due to splinters of glass. Modified or damaged
seat belts may tear or fail, e.g. in an accident.
Modified Emergency Tensioning Devices
could accidentally trigger or fail to deploy
when necessary. This poses an increased risk
of injury or even fatal injury.
Never modify the seat belts, Emergency Ten-
sioning Devices, belt anchorages and inertia
reels. Make sure that the seat belts are
undamaged, not worn out and clean. Follow-
ing an accident, have the seat belts checked
immediately at a qualified specialist work-
shop.
Only use seat belts that have been approved for
your vehicle by Mercedes-Benz.
Proper use of the seat belts
Observe the safety notes on the seat belt
( Y
page 43).
All vehicle occupants must be wearing the seat
belt correctly before beginning the journey. Also
make sure that all vehicle occupants are always
wearing the seat belt correctly while the vehicle
is in motion. When fastening the seat belt, always make sure
that: R
the seat belt tongue is only inserted to the belt
buckle belonging to that seat. R
the seat belt is tight across your body.
Avoid wearing bulky clothing, e.g. a winter
coat. R
the seat belt is not twisted.
Only then can the forces which occur be dis-
tributed over the area of the belt. R
the shoulder section of the belt is always
routed across the center of your shoulder.
The shoulder section of the belt must not
come into contact with your neck or be routed
under your arm. Where possible, adjust the
seat belt to the appropriate height. R
the lap belt passes tightly and as low down as
possible across your lap.
The lap belt must always be routed across
your hip joints and not across your abdomen.
This applies particularly to pregnant women.
If necessary, push the lap belt down to your
hip joint and pull it tight using the shoulder
section of the belt. R
the seat belt is not routed across sharp, poin-
ted or fragile objects.
If you have su ch i tems located on or in your
cl
othing, e.g. pens, keys or eyeglasses, store
these in a suitable place. R
only one person is using a seat belt at a time.
Infants and children must never travel sitting
on the lap of a vehicle occupant. In the event
of an accident, they could be crushed
between the vehicle occupant and seat belt. R
objects are never secured with a seat belt if
the seat belt is also being used by one of the
vehicle's occupants.
Also ensure that there are never objects
between a person and the seat, e.g. cushions.
Seat belts are only intended to secure and
restrain vehicle occupants. Always observe the
"Loading guidelines" for securing objects, lug-
gage or loads ( Y
page 294).
Fastening and adjusting the seat belts
Observe the safety notes on the seat belt
( Y
page 43) and the notes on correct use of seat
belts ( Y
page 44).44
Occupant safety
Safety

Basic illustration X
Adjust the seat ( Y
page 94).
The seat backrest must be in an almost ver-
tical position. X
Pull the seat belt smoothly from the belt outlet
and engage belt tongue D into belt
buckle C .
The seat belt on the driver’s seat and the
front-passenger seat may be tightened auto-
matically, see "Belt adjustment"
( Y
page 45). X
If necessary, pull upwards on the shoulder
section of the seat belt to tighten the belt
across your body.
The shoulder section of the seat belt must
always be routed across the center of the shoul-
der. Adjust the belt outlet if necessary. X
To raise: slide the belt outlet upwards.
The belt outlet will engage in various posi-
tions. X
To lower: hold belt outlet release

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 48) and on "Children in the
vehicle" ( Y
page 57 )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

R
no accessories, such as cup holders, are
attached to the vehicle within the deployment
area of an air bag, e.g. to doors, side windows,
rear side trim or side walls. R
no heavy, sharp-edged or fragile objects are in
the pockets of your clothing. Store such
objects in a suitable place.
G WARNING
If you modify the air bag cover or affix objects
such as stickers to it, the air bag can no longer
function correctly. There is an increased risk
of injury.
Never modify an air bag cover or affix objects
to it.
G WARNING
Sensors to control the air bags are located in
the doors. Modifications or work not per-
formed correctly to the doors or door panel-
ing, as well as damaged doors, can lead to the
function of the sensors being impaired. The air
bags might therefore not function properly
anymore. Consequently, the air bags cannot
protect vehicle occupants as they are
designed to do. There is an increased risk of
injury.
Never modify the doors or parts of the doors.
Always have work on the doors or door pan-
eling carried out at a qualified specialist work-
shop.
Front air bags
! Do not place heavy objects on the front-
passenger seat. This could cause the system
to identify the seat as being occupied. In the
event of an accident, the restraint systems on
the front-passenger side may be triggered
and have to be replaced. Driver's air bag C deploys in front of the steer-
ing wheel. Front-passenger front air bag D
deploys in front of and above the glove box.
When deployed, the front air bags offer addi-
tional head and thorax protection for the occu-
pants in the front seats.
The PASSENGER AIR BAG OFF indicator lamp
informs you about the status of the front-
passenger front air bag ( Y
page 42).
The front-passenger front air bag will only
deploy if: R
the system, based on the OCS weight sensor
readings, detects that the front-passenger
seat is occupied ( Y
page 48). The
PASSENGER AIR BAG OFF indicator lamp is
not lit ( Y
page 49) R
the restraint system control unit predicts a
high accident severity
Driver's knee bag
Driver's knee bag C deploys under the steering
column. The driver's knee bag is triggered
together with the front air bag.
The driver's knee bag offers additional thigh,
knee and lower leg protection for the occupant
in the driver's seat.Occupant safety 47
Safety Z

Side impact air bags
G WARNING
Unsuitable seat covers can obstruct or pre-
vent deployment of the air bags integrated
into the seats. Consequently, the air bags
cannot protect vehicle occupants as they are
designed to do. In addition, the operation of
the occupant classification system (OCS)
could be adversely affected. This poses an
increased risk of injury or even fatal injury.
You should only use seat covers that have
been approved for the respective seat by
Mercedes-Benz.
Front side impact air bags C and second row
rear side impact air bags D deploy next to the
outer bolster of the seat backrest.
When deployed, the side impact air bag offers
additional thorax protection. It also offers addi-
tional pelvis protection for occupants in the
front seats. However, it does not protect the: R
head R
neck R
arms
In the event of a side impact, the side impact air
bag is deployed on the side on which the impact
occurs.
The side impact air bag on the front-passenger
side deploys under the following conditions: R
the OCS system detects that the front-
passenger seat is occupied or R
the belt tongue is engaged in the belt buckle
of the front-passenger seat
If the belt tongue is engaged in the belt buckle,
the side impact air bag on the front-passenger
side deploys if an appropriate accident situation
occurs. In this case, deployment is independent of whether the front-passenger seat is occupied
or not.
Window curtain air bags
Window curtain air bags C are integrated into
the side of the roof frame and deploy in the area
extending from the front door (A-pillar) to the
rear side window (D-pillar).
When deployed, the window curtain air bag
enhances the level of protection for the head.
However, it does not protect the chest or arms.
In the event of a side impact, the window curtain
air bag is deployed on the side on which the
impact occurs.
If the system determines that they can offer
additional protection to that provided by the
seat belt, a window curtain air bag may be
deployed in other accident situations
( Y
page 53).
Occupant Classification System
(OCS)
Introduction The Occupant Classification System (OCS) cat-
egorizes the person in the front-passenger seat.
Depending on that result, the front-passenger
front air bag is either enabled or deactivated.
The system does not deactivate: R
the side impact air bag R
the window curtain air bag R
the Emergency Tensioning Devices48
Occupant safety
Safety