2023 GMC SIERRA Owners Manual

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
64 Seats and Restraints
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.
Seat Belt Extender
If the vehicle's seat belt will fasten around
you, you should use it.
But if a seat belt is not long enough, your
dealer will order you an extender. Only a
GM dealer issued extender should be used.
When you go in to order it, take the
heaviest coat you will wear, so the extender
will be long enough for you. To help avoid
personal injury, do not let someone else use
it, and use it only for the seat it is made to
fit. The extender has been designed for
adults. Never use it for securing child
restraints. For more information on the
proper use and fit of seat belt extenders see
the instruction sheet that comes with the
extender.
Safety System Check
Periodically check the seat belt reminder,
seat belts, buckles, latch plates, retractors,
shoulder belt height adjusters (if equipped),
and seat belt anchorages to make sure they
are all in working order. Look for any other
loose or damaged seat belt system parts
that might keep a seat belt system from
performing properly. See your dealer to
have it repaired. Torn, frayed, or twisted
seat belts may not protect you in a crash.Torn or frayed seat belts can rip apart under
impact forces. If a belt is torn or frayed,
have it replaced immediately. If a belt is
twisted, it may be possible to untwist by
reversing the latch plate on the webbing.
If the twist cannot be corrected, ask your
dealer to fix it.
Make sure the seat belt reminder light is
working. See
Seat Belt Reminders 0118.
Keep seat belts clean and dry. See Seat Belt
Care 064.
Seat Belt Care
Keep belts clean and dry.
Seat belts should be properly cared for and
maintained.
Seat belt hardware should be kept dry and
free of dust or debris. As necessary, exterior
hard surfaces and seat belt webbing may be
lightly cleaned with mild soap and water.
Ensure there is not excessive dust or debris
in the mechanism. If dust or debris exists in
the system please see the dealer. Parts may
need to be replaced to ensure proper
functionality of the system.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 65
{Warning
Do not bleach or dye seat belt webbing.
It may severely weaken the webbing. In
a crash, they might not be able to
provide adequate protection. Clean and
rinse seat belt webbing only with mild
soap and lukewarm water. Allow the
webbing to dry.
Replacing Seat Belt System Parts
after a Crash
{Warning
A crash can damage the seat belt system
in the vehicle. A damaged seat belt
system may not properly protect the
person using it, resulting in serious injury
or even death in a crash. To help make
sure the seat belt systems are working
properly after a crash, have them
inspected and any necessary
replacements made as soon as possible.
After a minor crash, replacement of seat
belts may not be necessary. But the seat
belt assemblies that were used during any crash may have been stressed or damaged.
See your dealer to have the seat belt
assemblies inspected or replaced.
New parts and repairs may be necessary
even if the seat belt system was not being
used at the time of the crash.
Have the seat belt pretensioners checked if
the vehicle has been in a crash, or if the
airbag readiness light stays on after you
start the vehicle or while you are driving.
See
Airbag Readiness Light 0119.
Airbag System
The vehicle has the following airbags:
.A frontal airbag for the driver
.A frontal airbag for the front outboard
passenger
.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 passenger seated
directly behind the front outboard
passenger
All vehicle airbags 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 side of the seatback
or side of the seat 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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
66 Seats and Restraints
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 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. SeeWhen Should an Airbag
Inflate? 068.
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
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.
{Warning
Children 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 075 or
Infants and Young Children 077.
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 0119.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 67
Where Are the Airbags?
The driver frontal airbag is in the center of
the steering wheel.
The front outboard passenger frontal airbag
is in the passenger side instrument panel.
Driver Side Shown, Passenger Side Similar
The driver and front outboard passenger
seat-mounted side impact airbags are in the
side of the seatbacks closest to the door.
Driver Side Crew Cab Shown, Passenger Side Double and Regular Cabs Similar
The roof-rail airbags for the driver, front
outboard passenger, and second row
outboard passengers 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
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 (Continued)

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
68 Seats and Restraints
Warning (Continued)
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 System065. 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 that 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 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, rear impacts,
or many side impacts.
In addition, the vehicle has advanced
technology frontal airbags. Advanced
technology frontal airbags adjust the
restraint according to crash severity.
Seat-mounted side impact airbags are
designed to inflate in moderate to severe
side crashes depending on the location of
the impact. These airbags may also inflate
in some moderate to severe frontal impacts.
Seat-mounted side impact airbags are not
designed to inflate in rollovers or rear
impacts. A seat-mounted side impact airbag
is designed to inflate on the side of the
vehicle that is struck.
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 may inflate during a
rollover or in a severe frontal impact.
Roof-rail airbags are not designed to inflate
in rear impacts. Both roof-rail airbags may
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.
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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 69
For airbag locations, seeWhere Are the
Airbags? 067.
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 68. Airbags should never be regarded as
anything more than a supplement to seat
belts.What Will You See after an
Airbag Inflates?
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? 067.
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.
{Warning
When an airbag inflates, there may be
dust in the air. This dust could cause
breathing problems for people with a
history of asthma or other breathing
trouble. To avoid this, everyone in the
vehicle should get out as soon as it is
safe to do so. If you have breathing
problems but cannot get out of the
vehicle after an airbag inflates, then get
fresh air by opening a window or a door.
If you experience breathing problems
following an airbag deployment, you
should seek medical attention.
The vehicle has a feature that may
automatically unlock the doors, turn on the
interior lamps and hazard warning flashers,
and shut off the fuel system after the
airbags inflate. The feature may also
activate, without airbag inflation, after an
event that exceeds a predetermined
threshold. After turning the ignition off and
then on again, the fuel system will return to
normal operation; the doors can be locked,
the interior lamps can be turned off, and
the hazard warning flashers can be turned

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
70 Seats and Restraints
off using the controls for those features.
If any of these systems are damaged in the
crash they may not operate as normal.
{Warning
A crash severe enough to inflate the
airbags may have also damaged
important functions in the vehicle, such
as the fuel system, brake and steering
systems, etc. Even if the vehicle appears
to be drivable after a moderate crash,
there may be concealed damage that
could make it difficult to safely operate
the vehicle.
Use caution if you should attempt to
restart the engine after a crash has
occurred.
In many crashes severe enough to inflate
the airbag, windshields are broken by
vehicle deformation. Additional windshield
breakage may also occur from the front
outboard passenger airbag.
.Airbags are designed to inflate only once.
After an airbag inflates, you will need
some new parts for the airbag system.
If you do not get them, the airbag
system will not be there to help protect
you in another crash. A new system will include airbag modules and possibly other
parts. The service manual for the vehicle
covers the need to replace other parts.
.The vehicle has a crash sensing and
diagnostic module which records
information after a crash. See
Vehicle
Data Recording and Privacy 0405 and
Event Data Recorders 0406.
.Let only qualified technicians work on the
airbag systems. Improper service can
mean that an airbag system will not work
properly. See your dealer for service.
Passenger Sensing System
The vehicle has a passenger sensing system
for the front outboard passenger position.
The passenger airbag status indicator will
light on the overhead console when the
vehicle is started.
United States
Canada
The words ON and OFF, or the symbols for
on and off, will be visible during the system
check. When the system check is complete,
either the word ON or OFF, or the symbol
for on or off, will be visible. See Passenger
Airbag Status Indicator 0119.
The passenger sensing system turns off the
front outboard passenger frontal airbag
under certain conditions. No other airbag is
affected by the passenger sensing system.
The passenger sensing system works with
sensors that are part of the front outboard
passenger seat and seat belt. The sensors
are designed to detect the presence of a
properly seated occupant and determine if
the front outboard passenger frontal airbag
should be allowed to inflate or not.
According to accident statistics, children are
safer when properly secured in a rear seat
in the correct child restraint for their weight
and size.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 71
Whenever possible, children aged 12 and
under should be secured in a rear seating
position.
Never put a rear-facing child seat in the
front. This is because the risk to the
rear-facing child is so great, if the airbag
inflates.
{Warning
A child in a rear-facing child restraint can
be seriously injured or killed if the
passenger frontal airbag inflates. This is
because the back of the rear-facing child
restraint would be very close to the
inflating airbag. A child in a
forward-facing child restraint can be
seriously injured or killed if the passenger
frontal airbag inflates and the passenger
seat is in a forward position.
Even if the passenger sensing system has
turned off the passenger frontal airbag,
no system is fail-safe. No one can
guarantee that an airbag will not deploy
under some unusual circumstance, even
though the airbag is turned off.(Continued)
Warning (Continued)
Never put a rear-facing child restraint in
the front seat, even if the airbag is off.
If securing a forward-facing child restraint
in the front outboard passenger seat,
always move the seat as far back as it
will go. It is better to secure child
restraints in the rear seat. Consider using
another vehicle to transport the child
when a rear seat is not available.
If the vehicle does not have a rear seat that
will accommodate a rear-facing child
restraint, a rear-facing child restraint should
not be installed in the vehicle, even if the
airbag is off.
The passenger sensing system is designed to
turn off the front outboard passenger
frontal airbag if:
.The front outboard passenger seat is
unoccupied.
.The system determines an infant is
present in a child restraint.
.A front outboard passenger takes his/her
weight off of the seat for a period
of time.
.There is a critical problem with the airbag
system or the passenger sensing system.
When the passenger sensing system has
turned off the front outboard passenger
frontal airbag, the OFF indicator will light
and stay lit as a reminder that the airbag is
off. See Passenger Airbag Status Indicator
0 119.
The passenger sensing system is designed to
turn on the front outboard passenger frontal
airbag anytime the system senses that a
person of adult size is sitting properly in the
front outboard passenger seat.
When the passenger sensing system has
allowed the airbag to be enabled, the ON
indicator will light and stay lit as a reminder
that the airbag is active.
For some children, including children in child
restraints, and for very small adults, the
passenger sensing system may or may not
turn off the front outboard passenger
frontal airbag, depending upon the person's
seating posture and body build. Everyone in
the vehicle who has outgrown child
restraints should wear a seat belt
properly —whether or not there is an
airbag for that person.