2018 GMC SIERRA DENALI tow

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 492. Press one of the four arrows on
the control pad while the
indicator light on button (1)
or (2) is illuminated, to move
the mirror in the desired
direction.
3. Adjust each outside mirror so
that a little of the vehicle and
the area behind it can be seen.
4. Press either (1) or (2) again to
deselect the mirror.
If you do not deselect the mirror, the
feature will turn off after about
one minute.
The mirrors may include a memory
function that works with the memory
seats. See Memory Seats 0 62 .Folding Mirrors
Crew/Double Cab Premium Trim
Shown, Other Models Similar
Power Folding If equipped with power folding
mirrors:
1. Press (2) to fold the mirrors out
to the driving position.
2. Press (2) again to fold the
mirrors in to the folded position.
The mirrors may also include a
memory function that works with the
memory seats. See Memory Seats
0 62 . Resetting the Power Folding
Mirrors
Reset the power folding mirrors if:
.
The mirrors are accidentally
obstructed while folding.
.
They are accidentally manually
folded/unfolded.
.
The mirrors will not stay in the
unfolded position.
.
The mirrors vibrate at normal
driving speeds.
Manually fold both mirrors if they
are out of sync. Fold and unfold the
mirrors three times using the mirror
controls to reset them to their
normal position. A popping noise
may be heard. This sound is normal
after a manual folding operation.
Manual Folding
If equipped, push the mirror toward
the vehicle to fold. Push the mirror
outward to return to its original
position.
Manually fold the mirrors inward to
prevent damage when going
through an automatic car wash.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
50 Keys, Doors, and Windows Auto Mirror Folding If equipped, with the ignition off,
press and hold
Q on the RKE
transmitter for approximately
one second to automatically fold the
exterior mirrors. Press and hold
Kon the RKE transmitter for
approximately one second to unfold.
See Remote Keyless Entry (RKE)
System Operation 0 37 .
This feature is turned on or off
through vehicle personalization. See
Vehicle Personalization 0 165 .
Turn Signal Indicator If equipped, indicator lights on the
mirror flash in the direction of the
turn or lane change.
Heated Mirrors If equipped with heated mirrors:
K : Press to heat the outside
mirrors. If the vehicle has trailer-tow
mirrors, only the upper glass of the
mirror is heated. The lower convex
part of the trailer-tow mirrors is not
heated. See “ Rear Window Defogger ” under
Dual Automatic Climate Control
System 0 228 .
Automatic Dimming
Mirror If equipped, the driver outside mirror
automatically adjusts for the glare of
the headlamps from behind. This
feature comes on when the vehicle
is started.
Blind Spot Mirrors If equipped, there is a small convex
mirror built into the upper and outer
corner of the driver outside mirror.
It can show objects that may be in
the vehicle's blind zone. Driving with the Blind Spot
Mirror
Actual Mirror View

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