2017 GMC SIERRA 1500 tow

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Keys, Doors, and Windows 43
Folding Mirrors
Crew/Double Cab Premium TrimShown, 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 054. 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.
Auto Mirror Folding
If equipped, with the ignition off,
press and hold
Qon the RKE
transmitter for approximately
one second to automatically fold the
exterior mirrors. Press and hold
K
on the RKE transmitter for
approximately one second to unfold.
See Remote Keyless Entry (RKE)
System Operation 031.
This feature is turned on or off
through vehicle personalization. See
Vehicle Personalization 0155.
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 mirrors. If the
vehicle has towing mirrors, only the
upper glass of the mirror is heated.
The lower convex part of the towing
mirrors is not heated.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Keys, Doors, and Windows 45
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 0155.
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 0471.
Do not spray glass cleaner directly
on the mirror. Use a soft towel
dampened with water.
Manual Rearview Mirror
If equipped, push the tab forward for
daytime use and pull it rearward for
nighttime use to avoid glare from
the headlamps from behind.
Automatic Dimming
Rearview Mirror
The mirror will automatically reduce
the glare of the headlamps from
behind. The dimming feature comes
on each time the vehicle is started.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Seats and Restraints 57
Rear Seats
Rear Seats (Double Cab
Full Bench)
Rear Seat Reminder (Full
Bench Only)
Look in Rear Seat Reminder
Feature
If equipped, this message displays
under certain conditions indicating
there may be an item or passenger
in the rear seat. Check before
exiting the vehicle.
This feature will activate when a
second row door is opened while
the vehicle is on or up to 10 minutes
before the vehicle is turned on,
including if the vehicle was started
remotely. There will be an alert
when the vehicle is turned off. The
alert does not directly detect objects
in the rear seat; instead, under
certain conditions, it detects when a
rear door is opened and closed,
indicating that there may be
something in the rear seat.The 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
through
Vehicle
Personalization 0155.
Folding the Rear Seat
Caution
Folding a rear seat with the safety
belts still fastened may cause
damage to the seat or the safety
belts. Always unbuckle the safety
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
58 Seats and Restraints
2. Pull up on the seat cushion tomake sure it is locked in place.
Make sure the safety belts are
not twisted or caught in the
seat cushion.
{Warning
A safety 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 safety belts are
properly routed and attached, and
are not twisted.
Rear Seats (Split Bench)
Folding the Rear Seat
Either side of the rear seat can be
folded for added cargo space.
Caution
Folding a rear seat with the safety
belts still fastened may cause
damage to the seat or the safety
belts. Always unbuckle the safety
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 safety belts are not
twisted or caught in the seat
cushion.
{Warning
A safety 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 safety belts are
properly routed and attached, and
are not twisted.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Seats and Restraints 71
are designed to inflate in moderate
to severe side crashes depending
on the location of the impact. Both
roof-rail airbags will inflate when
either side of the vehicle is struck.
In addition, these roof-rail airbags
are designed to inflate in a severe
frontal impact. If the vehicle has
single rear wheels and has a
factory-installed pickup box and
roof-rail airbags, the roof-rail airbags
are rollover capable. If the vehicle
has dual rear wheels, or is sold as
an incomplete vehicle, as a chassis
cab, or with the pickup box
removed, and has roof-rail airbags,
the roof-rail airbags are not rollover
capable. If the airbags are rollover
capable, both roof-rail airbags will
also inflate if the sensing system
predicts that the vehicle is about to
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, seeWhere Are
the Airbags? 068.
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 safety 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? 069.
Airbags should never be regarded
as anything more than a supplement
to safety belts.
What Will You See after
an Airbag Inflates?
For an eAssist vehicle, see the
Silverado/Sierra eAssist
supplement.
After the frontal airbags and
seat-mounted side impact airbags
inflate, they quickly deflate, so
quickly that some people may not

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
82 Seats and Restraints
Q: What is the proper way towear safety belts?
A: An older child should wear a
lap-shoulder belt and get the
additional restraint a shoulder
belt can provide. The shoulder
belt should not cross the face or
neck. The lap belt should fit
snugly below the hips, just
touching the top of the thighs.
This applies belt force to the
child's pelvic bones in a crash.
It should never be worn over the
abdomen, which could cause
severe or even fatal internal
injuries in a crash.
Also see “Rear Safety Belt Comfort
Guides” underLap-Shoulder
Belt 061.
According to accident statistics,
children are safer when properly
restrained in a rear seating position.
In a crash, children who are not
buckled up can strike other people
who are buckled up, or can be
thrown out of the vehicle. Older
children need to use safety belts
properly.{Warning
Never allow more than one child
to wear the same safety belt. The
safety belt cannot properly spread
the impact forces. In a crash, they
can be crushed together and
seriously injured. A safety belt
must be used by only one person
at a time.
{Warning
Never allow a child to wear the
safety belt with the shoulder belt
behind their back. A child can be
seriously injured by not wearing
the lap-shoulder belt properly. In a
crash, the child would not be
restrained by the shoulder belt.
The child could move too far
forward increasing the chance of
head and neck injury. The child
might also slide under the lap
belt. The belt force would then be
applied right on the abdomen.
That could cause serious or fatal
injuries. The shoulder belt should
go over the shoulder and across
the chest.