GMC ACADIA 2021 Repair Manual

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
60 Seats and Restraints
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.
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.
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.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
0 106.
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Seats and Restraints 61
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.
{Warning
If the airbag readiness light ever comes
on and stays on, it means that
something may be wrong with the airbag
system. To help avoid injury to yourself
or others, have the vehicle serviced right
away. See Airbag Readiness Light 0105
for more information, including important
safety information.
If the On Indicator Is Lit for a Child
Restraint
The passenger sensing system is designed to
turn off the front outboard passenger
frontal airbag if the system determines that
an infant is present in a child restraint. If a
child restraint has been installed and the ON
indicator is lit: 1. Turn the vehicle off.
2. Remove the child restraint from the
vehicle.
3. Remove any additional items from the seat such as blankets, cushions, seat
covers, seat heaters, or seat massagers.
4. Reinstall the child restraint following the directions provided by the child restraint
manufacturer and refer to Securing Child
Restraints (With the Seat Belt in the Rear
Seat) 078 or
Securing Child Restraints (With the Seat
Belt in the Front Seat) 080.
Make sure the seat belt retractor is
locked by pulling the shoulder belt all
the way out of the retractor when
installing the child restraint, even if the
child restraint is equipped with a seat
belt lock off. When the retractor lock is
set, the belt can be tightened but not
pulled out of the retractor.
5. If, after reinstalling the child restraint and restarting the vehicle, the ON
indicator is still lit, turn the vehicle off.
Then slightly recline the vehicle seatback
and adjust the seat cushion,
if adjustable, to make sure that the
vehicle seatback is not pushing the child
restraint into the seat cushion. Also make sure the child restraint is not
trapped under the vehicle head restraint.
If this happens, adjust the head restraint.
See
Head Restraints 035.
6. Restart the vehicle.
The passenger sensing system may or may
not turn off the airbag for a child in a child
restraint depending upon the child’s size.
It is better to secure the child restraint in a
rear seat. Never put a rear-facing child
restraint in the front seat, even if the ON
indicator is not lit.
If the Off Indicator Is Lit for an
Adult-Sized Occupant

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
62 Seats and Restraints
If a person of adult size is sitting in the
front outboard passenger seat, but the OFF
indicator is lit, it could be because that
person is not sitting properly in the seat or
that the child restraint locking feature is
engaged. Use the following steps to allow
the system to detect that person and enable
the front outboard passenger frontal airbag:1. Turn the vehicle off.
2. Remove any additional material from 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 063 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 seatback may interfere with the
proper operation of the passenger
sensing system.

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Seats and Restraints 63
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, seePublication Ordering
Information 0371.
{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 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, airbag wiring, or front
center console
.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'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 059.
If the vehicle has rollover roof-rail airbags,
see Different Size Tires and Wheels 0316 for
additional important information.
If the vehicle must be modified 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

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
64 Seats and Restraints
will be affected if the vehicle is modified for
any other reason, call Customer Assistance.
SeeCustomer Assistance Offices 0365.
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 0105.
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? 055. 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.
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 0105.
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
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.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 050. 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 050.
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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66 Seats and Restraints
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.

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Seats and Restraints 67
{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
passenger 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 a
forward-facing child restraint must be
secured in the front passenger seat,
always move the front passenger seat as
far back as it will go.
If a child restraint is installed in the
second row center seat, move the second
row seat to the rearward position,
whenever possible, to minimize contact
with the front center airbag.
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.
{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
(Continued)

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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68 Seats and Restraints
Warning (Continued)
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.
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 Children064.

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Seats and Restraints 69
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) 071 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 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.
The vehicle is equipped with a front center
airbag in the inboard side of the driver seat.
Even with a front center airbag, a child
restraint can be installed in any second row
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.