2018 GMC SIERRA DENALI Owners Manual

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
0 86 . 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 0 75 .
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, pull
up 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 0 70 .
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
74 Seats and Restraints Seat Belt Pretensioners This vehicle has seat belt
pretensioners for front outboard
occupants. Although the seat belt
pretensioners cannot be seen, they
are part of the seat belt assembly.
They can help tighten the seat 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,
seat belt pretensioners can help
tighten the seat belts in a side
crash. If the vehicle has rollover
roof-rail airbags, seat belt
pretensioners can help tighten the
seat belts in a rollover event.
Pretensioners work only once. If the
pretensioners activate in a crash,
the pretensioners and probably
other parts of the vehicle's seat belt
system will need to be replaced.
See Replacing Seat Belt System
Parts after a Crash 0 76 . Do not sit on the outboard seat belt
while entering or exiting the vehicle
or at any time while sitting in the
seat. Sitting on the seat belt can
damage the webbing and hardware.
Rear Seat Belt Comfort Guides Rear seat belt comfort guides may
provide added seat belt comfort for
older children who have outgrown
booster seats and for some adults.
When installed on a shoulder belt,
the comfort guide positions the
shoulder belt away from the neck
and head.
Comfort guides are available
through your dealer for the rear
outboard seating positions.
Instructions are included with the
guide.
Seat Belt Use During
Pregnancy Seat belts work for everyone,
including pregnant women. Like all
occupants, they are more likely to
be seriously injured if they do not
wear seat belts. A pregnant woman should wear a
lap-shoulder belt, and the lap
portion should be worn as low as
possible, below the rounding,
throughout the pregnancy.
The best way to protect the fetus is
to protect the mother. When a seat
belt is worn properly, it is more likely
that the fetus will not be hurt in a
crash. For pregnant women, as for
anyone, the key to making seat
belts effective is wearing them
properly.

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, see Lap-Shoulder Belt 0 71 .
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 0 75 .
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
76 Seats and Restraints Make sure the seat belt reminder
light is working. See Seat Belt
Reminders 0 146 .
Keep seat belts clean and dry. See
Seat Belt Care 0 76 .
Seat Belt Care Keep belts clean and dry.
{ WarningDo not bleach or dye seat belt
webbing. It may severely weaken
the webbing. In a crash, they
might not be able to provide
adequate protection. Clean and
rinse seat belt webbing only with
mild soap and lukewarm water.
Allow the webbing to dry.
Seat belts should be properly cared
for and maintained.
Seat belt hardware should be kept
dry and free of dust or debris. As
necessary exterior hard surfaces
and seat belt webbing may be lightly cleaned with mild soap and water.
Ensure there is not excessive dust
or debris in the mechanism. If dust
or debris exists in the system please
see the dealer. Parts may need to
be replaced to ensure proper
functionality of the system.
Replacing Seat Belt
System Parts after a
Crash
{ WarningA crash can damage the seat belt
system in the vehicle. A damaged
seat belt system may not properly
protect the person using it,
resulting in serious injury or even
death in a crash. To help make
sure the seat belt systems are
working properly after a crash,
have them inspected and any
necessary replacements made as
soon as possible. After a minor crash, replacement of
seat belts may not be necessary.
But the seat belt assemblies that
were used during any crash may
have been stressed or damaged.
See your dealer to have the seat
belt assemblies inspected or
replaced.
New parts and repairs may be
necessary even if the seat belt
system was not being used at the
time of the crash.
Have the seat belt pretensioners
checked if the vehicle has been in a
crash, or if the airbag readiness light
stays on after you start the vehicle
or while you are driving. See Airbag
Readiness Light 0 147 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 77
Airbag System The vehicle has the following
airbags:
.
A frontal airbag for the driver
.
A frontal airbag for the front
outboard passenger
The vehicle may have the following
airbags:
.
A seat-mounted side impact
airbag for the driver
.
A seat-mounted side impact
airbag for the front outboard
passenger
.
A roof-rail airbag for the driver
and the passenger seated
directly behind the driver
.
A roof-rail airbag for the front
outboard passenger and the
person seated directly behind
the front outboard passenger
All of the airbags in the vehicle will
have the word AIRBAG on the trim
or on a label near the deployment
opening. For frontal airbags, the word
AIRBAG is on the center of the
steering wheel for the driver and on
the instrument panel for the front
outboard passenger.
For seat-mounted side impact
airbags, the word AIRBAG is on the
seatback closest to the door.
For roof-rail airbags, the word
AIRBAG is on the ceiling or trim.
Airbags are designed to supplement
the protection provided by seat
belts. Even though today's airbags
are also designed to help reduce
the risk of injury from the force of an
inflating bag, all airbags must inflate
very quickly to do their job.
Here are the most important things
to know about the airbag system:
{ Warning
You can be severely injured or
killed in a crash if you are not
wearing your seat belt, even with
airbags. Airbags are designed to
(Continued) Warning (Continued) work with seat belts, not replace
them. Also, airbags are not
designed to inflate in every crash.
In some crashes seat belts are
the only restraint. See When
Should an Airbag Inflate? 0 80 .
Wearing your seat belt during a
crash helps reduce your chance
of hitting things inside the vehicle
or being ejected from it. Airbags
are “ supplemental restraints ” to
the seat belts. Everyone in the
vehicle should wear a seat belt
properly, whether or not there is
an airbag for that person.
{ Warning
Because airbags inflate with great
force and faster than the blink of
an eye, anyone who is up
against, or very close to, any
airbag when it inflates can be
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
78 Seats and Restraints Warning (Continued)seriously injured or killed. Do not
sit unnecessarily close to any
airbag, as you would be if sitting
on the edge of the seat or leaning
forward. Seat belts help keep you
in position before and during a
crash. Always wear a seat belt,
even with airbags. The driver
should sit as far back as possible
while still maintaining control of
the vehicle. The seat belts and
the front outboard passenger
airbags are most effective when
you are sitting well back and
upright in the seat with both feet
on the floor.
Occupants should not lean on or
sleep against the door or side
windows in seating positions with
seat-mounted side impact airbags
and/or roof-rail airbags. { WarningChildren who are up against,
or very close to, any airbag when
it inflates can be seriously injured
or killed. Always secure children
properly in the vehicle. To read
how, see Older Children 0 92 or
Infants and Young Children 0 94 .
There is an airbag readiness light
on the instrument cluster, which
shows the airbag symbol.
The system checks the airbag
electrical system for malfunctions.
The light tells you if there is an
electrical problem. See Airbag
Readiness Light 0 147 for more
information. Where Are the Airbags?
The driver frontal airbag is in the
center of the steering wheel.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 79
The front outboard passenger
frontal airbag is in the passenger
side instrument panel. Driver Side Shown, Passenger
Side Similar
If the vehicle has seat-mounted side
impact airbags for the driver and
front outboard passenger, they are
in the side of the seatbacks closest
to the door. Driver Side Crew Cab Shown,
Passenger Side Double and
Regular Cabs Similar
If the vehicle has roof-rail airbags
for the driver, front outboard
passenger, and second row
outboard passengers, they are in
the ceiling above the side windows.
{ Warning
If something is between an
occupant and an airbag, the
airbag might not inflate properly
or it might force the object into
(Continued)