z height GMC SIERRA 2018 Owner's Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
14 In Brief
PressCto ventilate the driver or
passenger seat.
See Heated and Ventilated Front
Seats 065.
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 058 and
Power Seat Adjustment 060.
Seat Belts
Refer to the following sections for
important information on how to use
seat belts properly:
.
Seat Belts 069.
. How to Wear Seat Belts Properly
070.
. Lap-Shoulder Belt 071.
. Lower Anchors and Tethers for
Children (LATCH System) 099.
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 084 for more information.
The passenger airbag status
indicator will be visible on the
overhead console when the vehicle
is started.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
58 Seats and Restraints
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 front seat outboard head
restraints are not removable.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 59
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) 099.
Front Seats
Seat Adjustment
{Warning
You can lose control of the
vehicle if you try to adjust a driver
seat while the vehicle is moving.
Adjust the driver seat only when
the vehicle is not moving.
To adjust a manual seat:
1. Pull the handle at the front of the seat. 2. Slide the seat to the desired
position and release the
handle.
3. Try to move the seat back and forth to be sure it is locked in
place.
To adjust the seatback, see
Reclining Seatbacks 061.
To adjust the lumbar support,
if equipped, see Lumbar Adjustment
0 60.
Center Seat
If equipped, the center front
seatback doubles as an armrest and
cupholder/storage area for the driver
and passenger when the center
front seat is not used. Do not use it
as a seating position when the
seatback is folded down.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
72 Seats and Restraints
The lap-shoulder belt may lock
if you pull the belt across you
very quickly. If this happens, let
the belt go back slightly to
unlock it. Then pull the belt
across you more slowly.
If the shoulder portion of a
passenger belt is pulled out all
the way, the child restraint
locking feature may be
engaged. If this happens, let
the belt go back all the way
and start again.
Engaging the child restraint
locking feature in the front
outboard seating position may
affect the passenger sensing
system, if equipped. See
Passenger Sensing System
086.
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 the
buckle until it clicks.
Pull up on the latch plate to
make sure it is secure. If the
belt is not long enough, see
Seat Belt Extender 075.
Position the release button on
the buckle so that the seat 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 73
5. To make the lap part tight, pullup on the shoulder belt.
To unlatch the belt, push the button
on the buckle. The belt should
return to its stowed position.
Always stow the seat belt slowly.
If the seat belt webbing returns
quickly to the stowed position, the
retractor may lock and cannot be
pulled out. If this happens, pull the
seat 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
seat belt is out of the way. If a door
is slammed against a seat belt,
damage can occur to both the seat
belt and the vehicle.
Shoulder Belt Height Adjuster
The vehicle has a shoulder belt
height adjuster for the driver and
front outboard passenger seating
positions.
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 adjustment could reduce the effectiveness of
the seat belt in a crash. See
How to
Wear Seat Belts Properly 070.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 75
Lap Belt
This section is only for the lap belt.
To learn how to wear a lap-shoulder
belt, seeLap-Shoulder Belt 071.
The vehicle may have a center
seating position with a lap seat belt.
The lap seat belt does not have a
retractor.
To make the belt longer, tilt the latch
plate and pull it along the belt.
Buckle, position, and release it the
same way as the lap part of a
lap-shoulder belt.
To make the belt shorter, pull its free
end as shown until the belt is snug.
If the belt is not long enough, see
Seat Belt Extender 075.
Make sure the release button on the
buckle is positioned so you would
be able to unbuckle the seat belt
quickly if necessary.
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. 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 or frayed seat belts
may not protect you in a crash.
They can rip apart under impact
forces. If a belt is torn or frayed,
have it replaced immediately.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
90 Seats and Restraints
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 090
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)
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
Information0474.
{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, seat
belts, airbag sensing and diagnostic
module, steering wheel, instrument
panel, inner door seals including the
speakers, any of the airbag
modules, ceiling or pillar garnish

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
92 Seats and Restraints
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 0147.
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 071.
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-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 95
Warning (Continued)
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
restraint.
{Warning
Children who are up against,
or very close to, any airbag when
it inflates can be seriously injured(Continued)
Warning (Continued)
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,

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
96 Seats and Restraints
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.
{Warning
A young child's hip bones are still
so small that the vehicle's regular
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(Continued)
Warning (Continued)
injuries. To reduce the risk of
serious or fatal injuries during a
crash, young children should
always be secured in appropriate
child restraints.
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.