Seats GMC SIERRA 2020 Service Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
82 Seats and Restraints
2. Remove any additional materialfrom the seat, such as
blankets, cushions, seat
covers, seat heaters, or seat
massagers.
3. Place the seatback in the fully upright position.
4. Have the person sit upright in the seat, centered on the seat
cushion, with legs comfortably
extended.
5. If the shoulder portion of the belt is pulled out all the way,
the child restraint locking
feature will be engaged. This
may unintentionally cause the
passenger sensing system to
turn the airbag off for some
adult-sized occupants. If this
happens, unbuckle the belt, let
the belt go back all the way,
and then buckle the belt again
without pulling the belt out all
the way.
6. Restart the vehicle and have the person remain in this
position for two to three minutes
after the ON indicator is lit.{Warning
If the front outboard passenger
airbag is turned off for an
adult-sized occupant, the airbag
will not be able to inflate and help
protect that person in a crash,
resulting in an increased risk of
serious injury or even death. An
adult-sized occupant should not
ride in the front outboard
passenger seat, if the passenger
airbag OFF indicator is lit.
Additional Factors Affecting
System Operation
Seat belts help keep the passenger
in position on the seat during
vehicle maneuvers and braking,
which helps the passenger sensing
system maintain the passenger
airbag status. See “Seat Belts”and
“Child Restraints” in the Index for
additional information about the
importance of proper restraint use. A thick layer of additional material,
such as a blanket or cushion,
or aftermarket equipment such as
seat covers, seat heaters, and seat
massagers can affect how well the
passenger sensing system
operates. We recommend that you
not use seat covers or other
aftermarket equipment except when
approved by GM for your specific
vehicle. See
Adding Equipment to
the Airbag-Equipped Vehicle 083
for more information about
modifications that can affect how
the system operates.
The ON indicator may be lit if an
object, such as a briefcase,
handbag, grocery bag, laptop,
or other electronic device, is put on
an unoccupied seat. If this is not
desired, remove the object from
the seat.
{Warning
Stowing articles under the
passenger seat or between the
passenger seat cushion and
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 83
Warning (Continued)
seatback may interfere with the
proper operation of the passenger
sensing system.
Servicing the
Airbag-Equipped Vehicle
Airbags affect how the vehicle
should be serviced. There are parts
of the airbag system in several
places around the vehicle. Your
dealer and the service manual have
information about servicing the
vehicle and the airbag system. To
purchase a service manual, see
Publication Ordering Information
0472.
{Warning
For up to 10 seconds after the
vehicle is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
(Continued)
Warning (Continued)
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet
metal, may keep the airbag system
from working properly.
The operation of the airbag system
can also be affected by changing,
including improperly repairing or
replacing, any parts of the following:
.Airbag system, including airbag
modules, front or side impact
sensors, sensing and diagnostic
module, or airbag wiring .
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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
84 Seats and Restraints
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).
SeePassenger Sensing System
0 78.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels 0401 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
0465.
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 0136.
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
(Continued)
Caution (Continued)
covering and/or airbag module
replaced. For the location of the
airbags, seeWhere Are the
Airbags? 074. See your dealer
for service.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 85
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 Light0136.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 068.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
86 Seats and Restraints
Q: What is the proper way towear 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” underLap-Shoulder Belt
0 68.
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 with the shoulder belt
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 87
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 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
88 Seats and Restraints
{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.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 89
{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.
Forward-Facing Child Restraint
A forward-facing child restraint
provides restraint for the child's
body with the harness.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
90 Seats and Restraints
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
Children 085.
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) 092 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
2. Instruction manual provided with the child 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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 91
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.
(Continued)
Warning (Continued)
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.
SeePassenger Sensing System
0 78 for additional information.
{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.