GMC SIERRA 2021 Manual PDF

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
70 Seats and Restraints
.Front seats, including stitching, seams,
or zippers
.Seat belts
.Steering wheel, instrument panel,
overhead console, ceiling trim, or pillar
garnish trim
.Inner door seals, including speakers
Your dealer and the service manual have
information about the location of the airbag
modules and sensors, sensing and diagnostic
module, and airbag wiring along with the
proper replacement procedures.
In addition, the vehicle has a passenger
sensing system for the front outboard
passenger position, which includes sensors
that are part of the passenger 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 066.
If the vehicle has rollover roof-rail airbags,
see Different Size Tires and Wheels 0377 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 the vehicle must be modified because you
have a disability and 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 0430.
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 0114.
Caution
If 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? 062. See your dealer
for service.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 71
Replacing Airbag System Parts
after a Crash
{Warning
A crash can damage the airbag systems
in the vehicle. A damaged airbag system
may not properly protect you and your
passenger(s) in a crash, resulting in
serious injury or even death. To help
make sure the airbag systems are
working properly after a crash, have
them inspected and any necessary
replacements made as soon as possible.
If an airbag inflates, you will need to
replace airbag system parts. See your dealer
for service.
If the airbag readiness light stays on after
the vehicle is started or comes on when you
are driving, the airbag system may not work
properly. Have the vehicle serviced right
away. See Airbag Readiness Light 0114.
Child Restraints
Older Children
Older children who have outgrown booster
seats should wear the vehicle’s seat belts.
The manufacturer instructions that come
with the booster seat state the weight and
height limitations for that booster. Use a
booster seat with a lap-shoulder belt until
the child passes the fit test below:
.Sit all the way back on the seat. Do the
knees bend at the seat edge? If yes,
continue. If no, return to the booster seat.
.Buckle the lap-shoulder belt. Does the
shoulder belt rest on the shoulder? If yes,
continue. If no, try using the rear seat belt comfort guide, if available. See
“Rear
Seat Belt Comfort Guides” under
Lap-Shoulder Belt 057. If a comfort guide
is not available, or if the shoulder belt
still does not rest on the shoulder, then
return to the booster seat.
.Does the lap belt fit low and snug on the
hips, touching the thighs? If yes, continue.
If no, return to the booster seat.
.Can proper seat belt fit be maintained for
the length of the trip? If yes, continue.
If no, return to the booster seat.
Q: What is the proper way to wear seat belts?
A: An older child should wear a lap-shoulder
belt and get the additional restraint a
shoulder belt can provide. The shoulder
belt should not cross the face or neck.
The lap belt should fit snugly below the
hips, just touching the top of the thighs.
This applies belt force to the child's
pelvic bones in a crash. It should never
be worn over the abdomen, which could
cause severe or even fatal internal
injuries in a crash.
Also see “Rear Seat Belt Comfort Guides”
under Lap-Shoulder Belt 057.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
72 Seats and Restraints
According to accident statistics, children are
safer when properly restrained in a rear
seating position.
In a crash, children who are not buckled up
can strike other people who are buckled up,
or can be thrown out of the vehicle. Older
children need to use seat belts properly.
{Warning
Never allow more than one child to wear
the same seat belt. The seat belt cannot
properly spread the impact forces. In a
crash, they can be crushed together and
seriously injured. A seat belt must be
used by only one person at a time.
{Warning
Never allow a child to wear the seat belt
shoulder belt under both arms or behind
their back. A child can be seriously
injured by not wearing the lap-shoulder
belt properly. In a crash, the child would
not be restrained by the shoulder belt.
The child could move too far forward
increasing the chance of head and neck
injury. The child might also slide under
the lap belt. The belt force would then be
applied right on the abdomen. That could
cause serious or fatal injuries. The
shoulder belt should go over the shoulder
and across the chest.
Infants and Young Children
Everyone in a vehicle needs protection! This
includes infants and all other children.
Neither the distance traveled nor the age
and size of the traveler changes the need,
for everyone, to use safety restraints. In
fact, the law in every state in the United
States and in every Canadian province says
children up to some age must be restrained
while in a vehicle.
{Warning
Children can be seriously injured or
strangled if a shoulder belt is wrapped
around their neck. The shoulder belt can(Continued)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 73
Warning (Continued)
tighten but cannot be loosened if it is
locked. The shoulder belt locks when it is
pulled all the way out of the retractor.
It unlocks when the shoulder belt is
allowed to go all the way back into the
retractor, but it cannot do this if it is
wrapped around a child’s neck. If the
shoulder belt is locked and tightened
around a child’s neck, the only way to
loosen the belt is to cut it.
Never leave children unattended in a
vehicle and never allow children to play
with the seat belts.
Every time infants and young children ride
in vehicles, they should have the protection
provided by appropriate child restraints.
Neither the vehicle's seat belt system nor its
airbag system is designed for them.
Children who are not restrained properly can
strike other people, or can be thrown out of
the vehicle.
{Warning
Never hold an infant or a child while
riding in a vehicle. Due to crash forces, an
infant or a child will become so heavy it
is not possible to hold it during a crash.
For example, in a crash at only
40 km/h (25 mph), a 5.5 kg (12 lb) infant
will suddenly become a 110 kg (240 lb)
force on a person's arms. An infant or
child should be secured in an appropriate
child restraint.
{Warning
Children who are up against, or very
close to, any airbag when it inflates can
be seriously injured or killed. Never put a
rear-facing child restraint in the front
outboard seat. Secure a rear-facing child
restraint in a rear seat. It is also better to
secure a forward-facing child restraint in
a rear seat. If you must secure a
forward-facing child restraint in the front
outboard seat, always move the front
passenger seat as far back as it will go.
Child restraints are devices used to restrain,
seat, or position children in the vehicle and
are sometimes called child seats or car seats.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
74 Seats and Restraints
There are three basic types of child
restraints:
.Forward-facing child restraints
.Rear-facing child restraints
.Belt-positioning booster seats
The proper child restraint for your child
depends on their size, weight, and age, and
also on whether the child restraint is
compatible with the vehicle in which it will
be used.
For each type of child restraint, there are
many different models available. When
purchasing a child restraint, be sure it is
designed to be used in a motor vehicle. If it
is, the child restraint will have a label saying
that it meets federal motor vehicle safety
standards.
The instruction manual that is provided with
the child restraint states the weight and
height limitations for that particular child
restraint. In addition, there are many kinds
of child restraints available for children with
special needs.
{Warning
To reduce the risk of neck and head
injury in a crash, infants and toddlers
should be secured in a rear-facing child
restraint until age two, or until they
reach the maximum height and weight
limits of their child restraint.
{Warning
A young child's hip bones are still so
small that the vehicle seat belt may not
remain low on the hip bones, as it
should. Instead, it may settle up around
the child's abdomen. In a crash, the belt
would apply force on a body area that is
unprotected by any bony structure. This
alone could cause serious or fatal injuries.
To reduce the risk of serious or fatal
injuries during a crash, young children
should always be secured in an
appropriate child restraint.
Child Restraint Systems
Rear-Facing Infant Restraint
A rear-facing child restraint provides
restraint with the seating surface against
the back of the infant.
The harness system holds the infant in place
and, in a crash, acts to keep the infant
positioned in the restraint.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 75
Forward-Facing Child Restraint
A forward-facing child restraint provides
restraint for the child's body with the
harness.Booster Seats
A belt-positioning booster seat is used for
children who have outgrown their
forward-facing child restraint. Boosters are
designed to improve the fit of the vehicle's
seat belt system until the child is large
enough for the vehicle seat belts to fit
properly without a booster seat. See the
seat belt fit test in Older Children071.
Securing an Add-On Child Restraint in
the Vehicle
{Warning
A child can be seriously injured or killed
in a crash if the child restraint is not
properly secured in the vehicle. Secure
the child restraint properly in the vehicle
using the vehicle seat belt or LATCH
system, following the instructions that
came with that child restraint and the
instructions in this manual.
To help reduce the chance of injury, the
child restraint must be secured in the
vehicle. Child restraints must be secured in
vehicle seats by lap belts or the lap belt
portion of a lap-shoulder belt, or by the
LATCH system. See Lower Anchors and
Tethers for Children (LATCH System) 077 for
more information. Children can be
endangered in a crash if the child restraint is
not properly secured in the vehicle.
When securing an add-on child restraint,
refer to the following:
1. Instruction labels provided on the child restraint

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
76 Seats and Restraints
2. Instruction manual provided with thechild restraint
3. This vehicle owner's manual
The child restraint instructions are
important, so if they are not available,
obtain a replacement copy from the
manufacturer.
Keep in mind that an unsecured child
restraint can move around in a collision or
sudden stop and injure people in the vehicle.
Be sure to properly secure any child
restraint in the vehicle —even when no
child is in it.
In some areas Certified Child Passenger
Safety Technicians (CPSTs) are available to
inspect and demonstrate how to correctly
use and install child restraints. In the U.S.,
refer to the National Highway Traffic Safety
Administration (NHTSA) website to locate
the nearest child safety seat inspection
station. For CPST availability in Canada,
check with Transport Canada or the
Provincial Ministry of Transportation office.Securing the Child Within the Child
Restraint
{Warning
A child can be seriously injured or killed
in a crash if the child is not properly
secured in the child restraint. Secure the
child properly following the instructions
that came with that child restraint.
Where to Put the Restraint
According to accident statistics, children and
infants are safer when properly restrained in
an appropriate child restraint secured in a
rear seating position.
Whenever possible, children aged 12 and
under should be secured in a rear seating
position.
Never put a rear-facing child restraint in the
front. This is because the risk to the
rear-facing child is so great if the airbag
deploys.
{Warning
A child in a rear-facing child restraint can
be seriously injured or killed if the front
passenger 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 front passenger airbag inflates and
the passenger seat is in a forward
position.
Even if the passenger sensing system has
turned off the front passenger frontal
airbag, no system is fail-safe. No one can
guarantee that an airbag will not deploy
under some unusual circumstance, even
though it is turned off.
Secure rear-facing child restraints in a
rear seat, even if the airbag is off. If you
secure a forward-facing child restraint in
the front seat, always move the front
passenger seat as far back as it will go.
It is better to secure the child restraint in
a rear seat.
See Passenger Sensing System 066 for
additional information.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 77
{Warning
A child in a child restraint in the center
front seat can be badly injured or killed
by the frontal airbags if they inflate.
Never secure a child restraint in the
center front seat. It is always better to
secure a child restraint in a rear seat.
Do not use child restraints in the center
front seat position.
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.
When securing a child restraint with the
seat belts in a rear seat position, study the
instructions that came with the child
restraint to make sure it is compatible with
this vehicle.
Child restraints and booster seats vary
considerably in size, and some may fit in
certain seating positions better than others.
Do not install a child restraint in any rear
seating position where it cannot be installed
securely. Depending on where you place the child
restraint and the size of the child restraint,
you may not be able to access adjacent seat
belts or LATCH anchors for additional
passengers or child restraints. Adjacent
seating positions should not be used if the
child restraint prevents access to or
interferes with the routing of the seat belt.
The seat in front of an installed child
restraint should be adjusted to ensure
proper installation according to the child
restraint manual.
Wherever a child restraint is installed, be
sure to follow the instructions that came
with the child restraint and secure the child
restraint properly.
Keep in mind that an unsecured child
restraint can move around in a collision or
sudden stop and injure people in the vehicle.
Be sure to properly secure any child
restraint in the vehicle
—even when no
child is in it.
Lower Anchors and Tethers for
Children (LATCH System)
The LATCH system secures a child restraint
during driving or in a crash. LATCH
attachments on the child restraint are used
to attach the child restraint to the anchors
in the vehicle. This system is designed to
make installation of a child restraint easier.
In order to use the LATCH system in your
vehicle, you need a child restraint that has
LATCH attachments. LATCH-compatible
rear-facing and forward-facing child seats can
be properly installed using either the LATCH
anchors or the vehicle’s seat belts. Do not
use both the seat belts and the LATCH
anchorage system to secure a rear-facing or
forward-facing child seat.
Booster seats use the vehicle’s seat belts to
secure the child and the booster seat. If the
manufacturer recommends that the booster
seat be secured with the LATCH system, this
can be done as long as the booster seat can
be positioned properly and there is no
interference with the proper positioning of
the lap-shoulder belt on the child.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
78 Seats and Restraints
Make sure to follow the instructions that
came with the child restraint, and also the
instructions in this manual.
When installing a child restraint with a top
tether, you must also use either the lower
anchors or the seat belts to properly secure
the child restraint. A child restraint must
never be installed using only the top tether.
For a forward-facing 5-pt harness child
restraint where the combined weight of the
child and restraint are up to 29.5 kg (65 lb),
use either the lower LATCH anchorages with
the top tether anchorage, or the seat belt
with the top tether anchorage. Where the
combined weight of the child and restraint
are greater than 29.5 kg (65 lb), use the seat
belt with the top tether anchorage only.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 79
Recommended Methods for Attaching Child Restraints
Restraint Type Combined Weight ofthe Child + Child
Restraint Use Only Approved Attachment Methods Shown with an X
LATCH
–Lower
Anchors Only Seat Belt Only LATCH
–Lower
Anchors and Top
Tether Anchor Seat Belt and Top
Tether Anchor
Rear-Facing Child
Restraint Up to 29.5 kg (65 lb)
X X
Rear-Facing Child
Restraint Greater than
29.5 kg (65 lb) X
Forward-Facing Child
Restraint Up to 29.5 kg (65 lb)
X X
Forward-Facing Child
Restraint Greater than
29.5 kg (65 lb) X
See Securing Child Restraints (With the Seat
Belt in the Center Front Seat) 092 or
Securing Child Restraints (With the Seat Belt
in the Rear Seat) 088 or
Securing Child Restraints (With the Seat Belt
in the Front Passenger Seat) 092. Child restraints built after March 2014 will
be labeled with the specific child weight up
to which the LATCH system can be used to
install the restraint.
The following explains how to attach a child
restraint with these attachments in the
vehicle. Not all vehicle seating positions have lower
anchors. In this case, the seat belt must be
used (with top tether where available) to
secure the child restraint. See
Securing Child
Restraints (With the Seat Belt in the Center
Front Seat) 092 or
Securing Child Restraints (With the Seat Belt
in the Rear Seat) 088 or
Securing Child Restraints (With the Seat Belt
in the Front Passenger Seat) 092.