
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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12 In Brief
PressCto ventilate the driver or
passenger seat.
See Heated and Ventilated Front
Seats 055.
Head Restraint
Adjustment
Do not drive until the head restraints
for all occupants are installed and
adjusted properly.
To achieve a comfortable seating
position, change the seatback
recline angle as little as necessary
while keeping the seat and the head
restraint height in the proper
position.
See Head Restraints 051 and
Power Seat Adjustment 052.
Safety Belts
Refer to the following sections for
important information on how to use
safety belts properly:
.
Safety Belts 059.
. How to Wear Safety Belts
Properly 060.
. Lap-Shoulder Belt 061.
. Lower Anchors and Tethers for
Children (LATCH System) 088.
Passenger Sensing
System
The passenger sensing system,
if equipped, turns off the front
outboard passenger frontal airbag
under certain conditions. No other
airbag is affected by the passenger
sensing system.
If the vehicle has one of the
indicators pictured in the following
illustrations, then the vehicle has a
passenger sensing system for the
front outboard passenger position
unless there is an airbag off switch
on the instrument panel endcap.
If there is an airbag off switch, the
vehicle does not have a passenger
sensing system. See Airbag On-Off
Switch 073 for more information.
The passenger airbag status
indicator will be visible on the
overhead console when the vehicle
is started.

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Seats and Restraints 51
Head Restraints
Front Seats
The vehicle’s front seats have
adjustable head restraints in the
outboard seating positions.
{Warning
With head restraints that are not
installed and adjusted properly,
there is a greater chance that
occupants will suffer a neck/
spinal injury in a crash. Do not
drive until the head restraints for
all occupants are installed and
adjusted properly.
Adjust the head restraint so that the
top of the restraint is at the same
height as the top of the occupant's
head. This position reduces the
chance of a neck injury in a crash.The height of the head restraint can
be adjusted. Pull the head restraint
up to raise it. Try to move the head
restraint to make sure that it is
locked in place.
To lower the head restraint, press
the button, located on the top of the
seatback, and push the restraint
down. Try to move the head
restraint after the button is released
to make sure that it is locked in
place.
The head restraints adjust forward
and rearward. To adjust the head
restraint forward, grasp the head
restraint and pull forward to the
desired locking position. To adjust

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52 Seats and Restraints
the head restraint rearward, grasp
the head restraint and pull forward
fully until the mechanism releases
and allows the head restraint to
return to the full rear position.
The front seat outboard head
restraints are not removable.
Rear Seats
The rear seat has adjustable
headrests in the outboard seating
positions.
The height of the headrest can be
adjusted. Pull the headrest up to
raise it. To lower the headrest, push
the headrest down.
If you are installing a child restraint
in the rear seat, see“Securing a
Child Restraint Designed for the
LATCH System” underLower
Anchors and Tethers for Children
(LATCH System) 088.
Front Seats
Power Seat Adjustment
To adjust a power seat:
.
Move the seat forward or
rearward by sliding the control
forward or rearward.
. Raise or lower the front part of
the seat cushion by moving the
front of the control up or down.
. Raise or lower the seat by
moving the rear of the control up
or down. To adjust the recline, see
Reclining
Seatbacks 053.
To adjust the lumbar support, see
Lumbar Adjustment 052.
Some vehicles are equipped with a
feature that activates a vibrating
pulse alert in the driver seat to help
the driver avoid crashes. See Driver
Assistance Systems 0290.
Lumbar Adjustment

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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62 Seats and Restraints
If the webbing locks in the latch
plate before it reaches the
buckle, tilt the latch plate flat to
unlock.
3. Push the latch plate into thebuckle until it clicks.
Pull up on the latch plate to
make sure it is secure. If the
belt is not long enough, see
Safety Belt Extender 065.
Position the release button on
the buckle so that the safety
belt could be quickly unbuckled
if necessary.
4. If equipped with a shoulder belt height adjuster, move it to the
height that is right for you. See
“Shoulder Belt Height Adjuster”
later in this section for
instructions on use and
important safety information.
5. To make the lap part tight, pullup on the shoulder belt.

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Seats and Restraints 63
To unlatch the belt, push the button
on the buckle. The belt should
return to its stowed position.
Always stow the safety belt slowly.
If the safety belt webbing returns
quickly to the stowed position, the
retractor may lock and cannot be
pulled out. If this happens, pull the
safety belt straight out firmly to
unlock the webbing, and then
release it. If the webbing is still
locked in the retractor, see your
dealer.
Before a door is closed, be sure the
safety belt is out of the way. If a
door is slammed against a safety
belt, damage can occur to both the
safety belt and the vehicle.
Shoulder Belt Height Adjuster
The vehicle has a shoulder belt
height adjuster for the driver and
front outboard passenger.
Adjust the height so the shoulder
portion of the belt is on the shoulder
and not falling off of it. The belt
should be close to, but not
contacting, the neck. Improper
shoulder belt height adjustmentcould reduce the effectiveness of
the safety belt in a crash. See
How
to Wear Safety Belts Properly 060.
Push down on the release button to
move the height adjuster to the
desired position.
Move the adjuster up by pushing up
on the shoulder belt guide.
After the adjuster is set to the
desired position, try to move it down
without pushing the release button
to make sure it has locked into
position.
Safety Belt Pretensioners
This vehicle has safety belt
pretensioners for front outboard
occupants. Although the safety belt
pretensioners cannot be seen, they
are part of the safety belt assembly.
They can help tighten the safety
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,
safety belt pretensioners can help
tighten the safety belts in a side
crash. If the vehicle has rollover
roof-rail airbags, safety belt
pretensioners can help tighten the
safety belts in a rollover event.
Pretensioners work only once. If the
pretensioners activate in a crash,
they will need to be replaced, and
the vehicle's safety belt system will
probably need other new parts. See
Replacing Safety Belt System Parts
after a Crash 066.
Do not sit on the outboard safety
belt while entering or exiting the
vehicle or at any time while sitting in

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Seats and Restraints 79
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. SeeAdding Equipment to
the Airbag-Equipped Vehicle 079
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 of articles under the
passenger seat or between the
passenger seat cushion and
(Continued)
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
Service Publications Ordering
Information0466.
{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 any
parts of the front seats, safety belts,
the airbag sensing and diagnostic
module, steering wheel, instrument
panel, any of the airbag modules,
ceiling headliner or pillar garnish
trim, overhead console, front
sensors, side impact sensors,
or airbag wiring.

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Seats and Restraints 81
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 0130.
Child Restraints
Older Children
Older children who have outgrown
booster seats should wear the
vehicle safety 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 safety
belt comfort guide, if available.
See “Rear Safety Belt Comfort
Guides” underLap-Shoulder Belt
0 61. 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 safety belt fit be
maintained for the length of the
trip? If yes, continue. If no,
return to the booster seat.
If you have the choice, a child
should sit in a position with a
lap-shoulder belt and get the
additional restraint a shoulder
belt can provide.

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84 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
. Rearward-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
restraint will have a label saying that
it meets federal motor vehicle safety
standards. The restraint
manufacturer's instructions that
come with the restraint state the
weight and height limitations for a
particular child restraint. In addition,
there are many kinds of 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.