tow GMC SIERRA DENALI 2018 User Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 511. When the approaching vehicle
is a long distance away, the
image in the main mirror is
small and near the inboard
edge of the mirror.
2. As the vehicle gets closer, the
image in the main mirror gets
larger and moves outboard.
3. As the vehicle enters the blind
zone, the image transitions
from the main mirror to the
blind spot mirror.
4. When the vehicle is in the blind
zone, the image only appears
in the blind spot mirror.
Using the Outside Mirror with
the Blind Spot Mirror 1. Set the main mirror so that the
side of the vehicle can just be
seen and the blind spot mirror
has an unobstructed view.
2. When checking for traffic or
before changing a lane, look at
the main driver/passenger side
mirror to observe traffic in the
adjacent lane, behind your
vehicle. Check the blind spot mirror for a vehicle in the blind
zone. Then, glance over your
shoulder to double check
before moving slowly into the
adjacent lane.
Reverse Tilt Mirrors If equipped with memory seats, the
passenger and/or driver mirror tilts
to a preselected position when the
vehicle is in R (Reverse). This
allows the curb to be seen when
parallel parking.
The mirror(s) return to the original
position when:
.
The vehicle is shifted out of
R (Reverse), or remains in
R (Reverse) for about
30 seconds.
.
The ignition is turned off.
.
The vehicle is driven in
R (Reverse) above a set speed.
To turn this feature on or off, see
Vehicle Personalization 0 165 .Interior Mirrors Interior Rearview Mirrors Adjust the rearview mirror for a clear
view of the area behind your
vehicle.
If equipped with OnStar, the vehicle
may have three control buttons at
the bottom of the mirror. See your
dealer for more information about
OnStar and how to subscribe to it.
See OnStar Overview 0 479 .
Do not spray glass cleaner directly
on the mirror. Use a soft towel
dampened with water.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 67The feature is active only once each
time the vehicle is turned on and off,
and will require reactivation by
opening and closing the second row
doors. There may be an alert even
when there is nothing in the rear
seat; for example, if a child entered
the vehicle through the rear door
and left the vehicle without the
vehicle being shut off.
The feature can be turned on or off.
See Vehicle Personalization 0 165 .
Folding the Rear Seat
CautionFolding a rear seat with the seat
belts still fastened may cause
damage to the seat or the seat
belts. Always unbuckle the seat
belts and return them to their
normal stowed position before
folding a rear seat. To fold the seat:
1. Pull up on the front of the seat
cushion while pulling down on
the release strap loop under
the seat cushion.
2. Pull the seat cushion up until it
latches with the seatback.
3. Pull forward on the seat
cushion to make sure it is
locked in place. To unfold the seat:
1. Push the seat cushion
rearward while pulling the
release strap loop under the
seat cushion. Pull the seat
cushion down until it latches.
2. Pull up on the seat cushion to
make sure it is locked in place.
Make sure the seat belts are
not twisted or caught in the
seat cushion.
{ WarningA seat belt that is improperly
routed, not properly attached,
or twisted will not provide the
protection needed in a crash. The
person wearing the belt could be
seriously injured. After raising the
rear seatback, always check to be
sure that the seat belts are
properly routed and attached, and
are not twisted.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
68 Seats and Restraints
Rear Seats (Split Bench) Folding the Rear Seat Either side of the rear seat can be
folded for added cargo space.
CautionFolding a rear seat with the seat
belts still fastened may cause
damage to the seat or the seat
belts. Always unbuckle the seat
belts and return them to their
normal stowed position before
folding a rear seat.
Make sure that nothing is on the
seat cushion. To fold the seat, slowly pull the seat
cushion up.
To return the seat to the normal
seating position, slowly pull the seat
cushion down.
Make sure the seat belts are not
twisted or caught in the seat
cushion. { WarningA seat belt that is improperly
routed, not properly attached,
or twisted will not provide the
protection needed in a crash. The
person wearing the belt could be
seriously injured. After raising the
rear seatback, always check to be
sure that the seat belts are
properly routed and attached, and
are not twisted.

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
82 Seats and Restraints roll over on its side. The roof-rail
airbags are not designed to inflate in
rear impacts.
In any particular crash, no one can
say whether an airbag should have
inflated simply because of the
vehicle damage or repair costs.
What Makes an Airbag
Inflate? In a deployment event, the sensing
system sends an electrical signal
triggering a release of gas from the
inflator. Gas from the inflator fills the
airbag causing the bag to break out
of the cover. The inflator, the airbag,
and related hardware are all part of
the airbag module.
For airbag locations, see Where Are
the Airbags? 0 78 .
How Does an Airbag
Restrain? In moderate to severe frontal or
near frontal collisions, even belted
occupants can contact the steering
wheel or the instrument panel. In moderate to severe side collisions,
even belted occupants can contact
the inside of the vehicle.
Airbags supplement the protection
provided by seat belts by
distributing the force of the impact
more evenly over the
occupant's body.
Rollover capable roof-rail airbags
are designed to help contain the
head and chest of occupants in the
outboard seating positions in the
first and second rows. The rollover
capable roof-rail airbags are
designed to help reduce the risk of
full or partial ejection in rollover
events, although no system can
prevent all such ejections.
But airbags would not help in many
types of collisions, primarily
because the occupant's motion is
not toward those airbags. See When
Should an Airbag Inflate? 0 80 .
Airbags should never be regarded
as anything more than a supplement
to seat belts. What Will You See after
an Airbag Inflates? For an eAssist vehicle, see the
Silverado/Sierra eAssist
supplement.
After frontal and seat-mounted side
impact airbags inflate, they quickly
deflate, so quickly that some people
may not even realize the airbags
inflated. Roof-rail airbags may still
be at least partially inflated for some
time after they inflate. Some
components of the airbag module
may be hot for several minutes. For
location of the airbags, see Where
Are the Airbags? 0 78 .
The parts of the airbag that come
into contact with you may be warm,
but not too hot to touch. There may
be some smoke and dust coming
from the vents in the deflated
airbags. Airbag inflation does not
prevent the driver from seeing out of
the windshield or being able to steer
the vehicle, nor does it prevent
people from leaving the vehicle.

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. See Adding Equipment to
the Airbag-Equipped Vehicle 0 90
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
Information 0 474 .
{ 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
104 Seats and Restraints
{ WarningChildren 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.
Buckle any unused seat belts
behind the child restraint so
children cannot reach them. Pull
the shoulder belt all the way out
of the retractor to set the lock,
and tighten the belt behind the
child restraint after the child
restraint has been installed. CautionDo not let the LATCH
attachments rub against the
vehicle ’ s seat belts. This may
damage these parts. If necessary,
move buckled seat belts to avoid
rubbing the LATCH attachments.
Do not fold the rear seatback
when the seat is occupied. Do not
fold the empty rear seat with a
seat belt buckled. This could
damage the seat belt or the seat.
Unbuckle and return the seat belt
to its stowed position, before
folding the seat.
If you need to secure more than one
child restraint in the rear seat, see
Where to Put the Restraint 0 98 .
This system is designed to make
installation of child restraints easier.
When using lower anchors, do not
use the vehicle's belts. Instead use
the vehicle's anchors and child
restraint attachments to secure the restraints. Some restraints also use
another vehicle anchor to secure a
top tether.
Regular Cab Models
1. For models without a rear seat,
forward-facing child restraints
should only be installed in the
right front seating position with
belts and a top tether. See
Securing Child Restraints (With
the Seat Belt in the Center
Front Seat) 0 114 or Securing
Child Restraints (With the Seat
Belt in the Front Passenger
Seat) 0 115 or Securing Child
Restraints (With the Seat Belt
in the Rear Seat) 0 111 .
If the child restraint
manufacturer recommends that
the top tether be attached,
attach and tighten the top
tether to the top tether anchor,
if your vehicle has one. Refer
to the child restraint
instructions and the following
steps:

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
110 Seats and Restraints To reinstall the headrest:
1. Insert the headrest posts into
the holes in the top of the
seatback with the longer
chrome plated post toward the
driver side of the vehicle.
2. Push the headrest all the way
down until it contacts the top of
the seatback.
Double Cab Models
The rear outboard headrests should
be removed when installing
forward-facing child restraints. To remove the headrest:
1. Press both buttons on the
headrest posts and pull up on
the headrest.
2. Store the headrest in a secure
place.
3. When the child restraint is
removed, reinstall the headrest
before the seating position
is used. To reinstall the headrest:
1. Insert the headrest posts into
the holes in the top of the
seatback with the longer
chrome plated post toward the
driver side of the vehicle.
2. Push the headrest all the way
down until it contacts the top of
the seatback.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 1137. For forward-facing child
restraints, attach and tighten
the top tether to the top tether
anchor (loop). Refer to the child
restraint instructions, the
vehicle LATCH anchor weight
limits and instructions listed in
Lower Anchors and Tethers for
Children (LATCH System) 0 99 .
8. Before placing a child in the
child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the seat belt path and
attempt to move it side to side
and back and forth. When the
child restraint is properly
installed, there should be no
more than 2.5 cm (1 in) of
movement.
To remove the child restraint,
unbuckle the vehicle seat belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.
Reinstall the headrest before the
seating position is used. See
“ Headrest Removal and Reinstallation ” under Lower Anchors
and Tethers for Children (LATCH
System) 0 99 for additional
information on installing the
headrest properly.
Crew Cab 1. Put the child restraint on
the seat.
2. Pick up the latch plate, and run
the lap and shoulder portions
of the vehicle's seat belt
through or around the restraint.
The child restraint instructions
will show you how. 3. Push the latch plate into the
buckle until it clicks.
Position the release button on
the buckle, away from the child
restraint system, so that the
seat belt could be quickly
unbuckled if necessary.
4. Pull the shoulder belt all the
way out of the retractor to set
the lock. When the retractor
lock is set, the belt can be
tightened but not pulled out of
the retractor.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
114 Seats and Restraints
5. To tighten the belt, push down
on the child restraint, pull the
shoulder portion of the belt to
tighten the lap portion of the
belt, and feed the shoulder belt
back into the retractor. When
installing a forward-facing child
restraint, it may be helpful to
use your knee to push down on
the child restraint as you
tighten the belt.
Try to pull the belt out of the
retractor to make sure the
retractor is locked. If the
retractor is not locked, repeat
Steps 4 and 5. 6. If the child restraint has a top
tether, follow the child restraint
manufacturer's instructions
regarding the use of the top
tether. See Lower Anchors and
Tethers for Children (LATCH
System) 0 99 for more
information on using the top
tether anchors.
7. Before placing a child in the
child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the seat belt path and
attempt to move it side to side
and back and forth. When the
child restraint is properly
installed, there should be no
more than 2.5 cm (1 in) of
movement.
To remove the child restraint,
unbuckle the vehicle seat belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.
For outboard rear seating positions,
if the child restraint cannot be
installed properly with the headrest
in place, the headrest may be removed. See your dealer for
assistance with removal, and store
the removed headrest in a secure
place. When the child restraint is
removed, reinstall the headrest
before the seating position is used.
For reinstallation instructions, see
“ Headrest Removal and
Reinstallation ” under Lower Anchors
and Tethers for Children (LATCH
System) 0 99 .
Securing Child Restraints
(With the Seat Belt in the
Center Front Seat)
{ 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.