2018 GMC SIERRA DENALI roof

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
74 Seats and Restraints Seat Belt Pretensioners This vehicle has seat belt
pretensioners for front outboard
occupants. Although the seat belt
pretensioners cannot be seen, they
are part of the seat belt assembly.
They can help tighten the seat belts
during the early stages of a
moderate to severe frontal, near
frontal, or rear crash if the threshold
conditions for pretensioner
activation are met. And, if your
vehicle has side impact airbags,
seat belt pretensioners can help
tighten the seat belts in a side
crash. If the vehicle has rollover
roof-rail airbags, seat belt
pretensioners can help tighten the
seat belts in a rollover event.
Pretensioners work only once. If the
pretensioners activate in a crash,
the pretensioners and probably
other parts of the vehicle's seat belt
system will need to be replaced.
See Replacing Seat Belt System
Parts after a Crash 0 76 . Do not sit on the outboard seat belt
while entering or exiting the vehicle
or at any time while sitting in the
seat. Sitting on the seat belt can
damage the webbing and hardware.
Rear Seat Belt Comfort Guides Rear seat belt comfort guides may
provide added seat belt comfort for
older children who have outgrown
booster seats and for some adults.
When installed on a shoulder belt,
the comfort guide positions the
shoulder belt away from the neck
and head.
Comfort guides are available
through your dealer for the rear
outboard seating positions.
Instructions are included with the
guide.
Seat Belt Use During
Pregnancy Seat belts work for everyone,
including pregnant women. Like all
occupants, they are more likely to
be seriously injured if they do not
wear seat belts. A pregnant woman should wear a
lap-shoulder belt, and the lap
portion should be worn as low as
possible, below the rounding,
throughout the pregnancy.
The best way to protect the fetus is
to protect the mother. When a seat
belt is worn properly, it is more likely
that the fetus will not be hurt in a
crash. For pregnant women, as for
anyone, the key to making seat
belts effective is wearing them
properly.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 77
Airbag System The vehicle has the following
airbags:
.
A frontal airbag for the driver
.
A frontal airbag for the front
outboard passenger
The vehicle may have the following
airbags:
.
A seat-mounted side impact
airbag for the driver
.
A seat-mounted side impact
airbag for the front outboard
passenger
.
A roof-rail airbag for the driver
and the passenger seated
directly behind the driver
.
A roof-rail airbag for the front
outboard passenger and the
person seated directly behind
the front outboard passenger
All of the airbags in the vehicle will
have the word AIRBAG on the trim
or on a label near the deployment
opening. For frontal airbags, the word
AIRBAG is on the center of the
steering wheel for the driver and on
the instrument panel for the front
outboard passenger.
For seat-mounted side impact
airbags, the word AIRBAG is on the
seatback closest to the door.
For roof-rail airbags, the word
AIRBAG is on the ceiling or trim.
Airbags are designed to supplement
the protection provided by seat
belts. Even though today's airbags
are also designed to help reduce
the risk of injury from the force of an
inflating bag, all airbags must inflate
very quickly to do their job.
Here are the most important things
to know about the airbag system:
{ Warning
You can be severely injured or
killed in a crash if you are not
wearing your seat belt, even with
airbags. Airbags are designed to
(Continued) Warning (Continued) work with seat belts, not replace
them. Also, airbags are not
designed to inflate in every crash.
In some crashes seat belts are
the only restraint. See When
Should an Airbag Inflate? 0 80 .
Wearing your seat belt during a
crash helps reduce your chance
of hitting things inside the vehicle
or being ejected from it. Airbags
are “ supplemental restraints ” to
the seat belts. Everyone in the
vehicle should wear a seat belt
properly, whether or not there is
an airbag for that person.
{ Warning
Because airbags inflate with great
force and faster than the blink of
an eye, anyone who is up
against, or very close to, any
airbag when it inflates can be
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
78 Seats and Restraints Warning (Continued)seriously injured or killed. Do not
sit unnecessarily close to any
airbag, as you would be if sitting
on the edge of the seat or leaning
forward. Seat belts help keep you
in position before and during a
crash. Always wear a seat belt,
even with airbags. The driver
should sit as far back as possible
while still maintaining control of
the vehicle. The seat belts and
the front outboard passenger
airbags are most effective when
you are sitting well back and
upright in the seat with both feet
on the floor.
Occupants should not lean on or
sleep against the door or side
windows in seating positions with
seat-mounted side impact airbags
and/or roof-rail airbags. { WarningChildren who are up against,
or very close to, any airbag when
it inflates can be seriously injured
or killed. Always secure children
properly in the vehicle. To read
how, see Older Children 0 92 or
Infants and Young Children 0 94 .
There is an airbag readiness light
on the instrument cluster, which
shows the airbag symbol.
The system checks the airbag
electrical system for malfunctions.
The light tells you if there is an
electrical problem. See Airbag
Readiness Light 0 147 for more
information. Where Are the Airbags?
The driver frontal airbag is in the
center of the steering wheel.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 79
The front outboard passenger
frontal airbag is in the passenger
side instrument panel. Driver Side Shown, Passenger
Side Similar
If the vehicle has seat-mounted side
impact airbags for the driver and
front outboard passenger, they are
in the side of the seatbacks closest
to the door. Driver Side Crew Cab Shown,
Passenger Side Double and
Regular Cabs Similar
If the vehicle has roof-rail airbags
for the driver, front outboard
passenger, and second row
outboard passengers, they are in
the ceiling above the side windows.
{ Warning
If something is between an
occupant and an airbag, the
airbag might not inflate properly
or it might force the object into
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
80 Seats and Restraints Warning (Continued)that person causing severe injury
or even death. The path of an
inflating airbag must be kept
clear. Do not put anything
between an occupant and an
airbag, and do not attach or put
anything on the steering wheel
hub or on or near any other
airbag covering.
Do not use seat accessories that
block the inflation path of a
seat-mounted side impact airbag.
Never secure anything to the roof
of a vehicle with roof-rail airbags
by routing a rope or tie ‐ down
through any door or window
opening. If you do, the path of an
inflating roof-rail airbag will be
blocked. When Should an Airbag
Inflate? This vehicle is equipped with
airbags. See Airbag System 0 77 .
Airbags are designed to inflate if the
impact exceeds the specific airbag
system's deployment threshold.
Deployment thresholds are used to
predict how severe a crash is likely
to be in time for the airbags to
inflate and help restrain the
occupants. The vehicle has
electronic sensors which help the
airbag system determine the
severity of the impact. Deployment
thresholds can vary with specific
vehicle design.
Frontal airbags are designed to
inflate in moderate to severe frontal
or near frontal crashes to help
reduce the potential for severe
injuries, mainly to the driver's or
front outboard passenger's head
and chest.
Whether the frontal airbags will or
should inflate is not based primarily
on how fast the vehicle is traveling. It depends on what is hit, the
direction of the impact, and how
quickly the vehicle slows down.
Frontal airbags may inflate at
different crash speeds depending on
whether the vehicle hits an object
straight on or at an angle, and
whether the object is fixed or
moving, rigid or deformable, narrow
or wide.
Frontal airbags are not intended to
inflate during vehicle rollovers, in
rear impacts, or in many side
impacts.
In addition, if the GVWR (Gross
Vehicle Weight Rating) is at or
below 3 855 kg (8,500 lb), the
vehicle has advanced technology
frontal airbags. You can find the
GVWR on the Certification/Tire label
on the center pillar of the vehicle.
See Vehicle Load Limits 0 248 for
more information.
Advanced technology frontal airbags
adjust the restraint according to
crash severity. Vehicles with
advanced technology frontal airbags
have a seat position sensor that

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 81enables the sensing system to
monitor the position of the driver
seat. The seat position sensor
provides information that is used to
adjust the deployment of the driver
frontal airbag.
If the GVWR is at or below 4 536 kg
(10,000 lb), the vehicle has
seat-mounted side impact airbags.
Vehicles with a GVWR above
4 536 kg (10,000 lb) may or may not
have seat-mounted side impact
airbags. Seat-mounted side impact
airbags, if equipped, are designed
to inflate in moderate to severe side
crashes depending on the location
of the impact. Seat-mounted side
impact airbags are not designed to
inflate in frontal impacts, near frontal
impacts, rollovers, or rear impacts.
A seat-mounted side impact airbag
is designed to inflate on the side of
the vehicle that is struck.
Vehicles with a GVWR at or below
3 855 kg (8,500 lb) have roof-rail
airbags. These roof-rail airbags are
designed to inflate in moderate to
severe side crashes depending on
the location of the impact. In addition, these roof-rail airbags are
designed to inflate during a rollover
or in a severe frontal impact. The
roof-rail airbags are not designed to
inflate in rear impacts. Both roof-rail
airbags will inflate when either side
of the vehicle is struck or if the
sensing system predicts that the
vehicle is about to roll over on its
side, or in a severe frontal impact.
Vehicles with a GVWR above
3 855 kg (8,500 lb) up to and
including 4 536 kg (10,000 lb) also
have roof-rail airbags. These
roof-rail airbags are designed to
inflate in moderate to severe side
crashes depending on the location
of the impact. Both roof-rail airbags
will inflate when either side of the
vehicle is struck. In addition, these
roof-rail airbags are designed to
inflate in a severe frontal impact.
The roof-rail airbags are also
rollover capable except on models
sold as an incomplete vehicle with
the pickup box removed. If the
roof-rail airbags are rollover
capable, both roof-rail airbags will
also inflate if the sensing system
predicts that the vehicle is about to roll over on its side. The roof-rail
airbags are not designed to inflate in
rear impacts.
Vehicles with a GVWR above
4 536 kg (10,000 lb) may or may not
be equipped with roof-rail airbags.
These roof-rail airbags, if equipped,
are designed to inflate in moderate
to severe side crashes depending
on the location of the impact. Both
roof-rail airbags will inflate when
either side of the vehicle is struck.
In addition, these roof-rail airbags
are designed to inflate in a severe
frontal impact. If the vehicle has
single rear wheels and has a
factory-installed pickup box and
roof-rail airbags, the roof-rail airbags
are rollover capable. If the vehicle
has dual rear wheels, or is sold as
an incomplete vehicle, as a chassis
cab, or with the pickup box
removed, and has roof-rail airbags,
the roof-rail airbags are not rollover
capable. If the airbags are rollover
capable, both roof-rail airbags will
also inflate if the sensing system
predicts that the vehicle is about to

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
82 Seats and Restraints roll over on its side. The roof-rail
airbags are not designed to inflate in
rear impacts.
In any particular crash, no one can
say whether an airbag should have
inflated simply because of the
vehicle damage or repair costs.
What Makes an Airbag
Inflate? In a deployment event, the sensing
system sends an electrical signal
triggering a release of gas from the
inflator. Gas from the inflator fills the
airbag causing the bag to break out
of the cover. The inflator, the airbag,
and related hardware are all part of
the airbag module.
For airbag locations, see Where Are
the Airbags? 0 78 .
How Does an Airbag
Restrain? In moderate to severe frontal or
near frontal collisions, even belted
occupants can contact the steering
wheel or the instrument panel. In moderate to severe side collisions,
even belted occupants can contact
the inside of the vehicle.
Airbags supplement the protection
provided by seat belts by
distributing the force of the impact
more evenly over the
occupant's body.
Rollover capable roof-rail airbags
are designed to help contain the
head and chest of occupants in the
outboard seating positions in the
first and second rows. The rollover
capable roof-rail airbags are
designed to help reduce the risk of
full or partial ejection in rollover
events, although no system can
prevent all such ejections.
But airbags would not help in many
types of collisions, primarily
because the occupant's motion is
not toward those airbags. See When
Should an Airbag Inflate? 0 80 .
Airbags should never be regarded
as anything more than a supplement
to seat belts. What Will You See after
an Airbag Inflates? For an eAssist vehicle, see the
Silverado/Sierra eAssist
supplement.
After frontal and seat-mounted side
impact airbags inflate, they quickly
deflate, so quickly that some people
may not even realize the airbags
inflated. Roof-rail airbags may still
be at least partially inflated for some
time after they inflate. Some
components of the airbag module
may be hot for several minutes. For
location of the airbags, see Where
Are the Airbags? 0 78 .
The parts of the airbag that come
into contact with you may be warm,
but not too hot to touch. There may
be some smoke and dust coming
from the vents in the deflated
airbags. Airbag inflation does not
prevent the driver from seeing out of
the windshield or being able to steer
the vehicle, nor does it prevent
people from leaving the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 91trim, overhead console, front
sensors, side impact sensors,
or airbag wiring.
Your dealer and the service manual
have information about the location
of the airbag sensors, sensing and
diagnostic module, and airbag
wiring.
In addition, the vehicle may have a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger ’ s seat. The
passenger sensing system may not
operate properly if the original seat
trim is replaced with non-GM
covers, upholstery, or trim; or with
GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad
or device, installed under or on top
of the seat fabric, could also
interfere with the operation of the
passenger sensing system. This
could either prevent proper
deployment of the passenger
airbag(s) or prevent the passenger
sensing system from properly turning off the passenger airbag(s).
See Passenger Sensing System
0 86 .
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels 0 409 for additional
important information.
If a snow plow is added to the
vehicle, the airbags should still work
properly. The airbag systems were
designed to work properly under a
wide range of conditions, including
snow plowing with vehicles that
have the optional snow plow prep
package (RPO VYU). Do not
change or defeat the snow plow's
“ tripping mechanism. ” If you do, it
can damage the snow plow and the
vehicle, and may cause an airbag
deployment.
If you have to modify your vehicle
because you have a disability and
you have questions about whether
the modifications will affect the
vehicle's airbag system, or if you
have questions about whether the
airbag system will be affected if the
vehicle is modified for any other reason, call Customer Assistance.
See Customer Assistance Offices
0 467 .
Airbag System Check The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See
Airbag Readiness Light 0 147 .
CautionIf an airbag covering is damaged,
opened, or broken, the airbag
may not work properly. Do not
open or break the airbag
coverings. If there are any
opened or broken airbag
coverings, have the airbag
covering and/or airbag module
replaced. For the location of the
airbags, see Where Are the
Airbags? 0 78 . See your dealer
for service.