tow GMC SIERRA 2020 User Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Keys, Doors, and Windows 43
Power Mirrors
To adjust each mirror:1. Press
jor|to select the
driver or passenger side mirror.
The indicator light will
illuminate.
2. Press the arrows on the control pad 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
jor|again to
deselect the mirror. Turn Signal Indicator
If equipped, the mirror has turn
signal indicator lights, which flash in
the direction of the turn or lane
change.
Task Lighting
If equipped, task lighting projects
light from the outside mirrors to the
sides of the vehicle. See
Task
Lighting 0171.
Puddle Lamps
If equipped, puddle lamps project
light from the bottom of the mirror to
the area of ground below the driver
and passenger doors. See Entry
Lighting 0173 and
Exit Lighting 0173.
Memory Mirrors
The vehicle may have memory
mirrors. See Memory Seats 059.
Lane Change Alert (LCA)
The vehicle may have LCA. See
Lane Change Alert (LCA) 0274.
Folding Mirrors
Manual Folding Mirrors
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.
Power Folding Mirrors
If equipped with power folding
mirrors:

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
46 Keys, Doors, and Windows
Interior Mirrors
Interior Rearview Mirrors
Adjust the rearview mirror for a clear
view of the area behind your
vehicle.
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
If equipped, the mirror will
automatically reduce the glare of the
headlamps from behind. The
dimming feature comes on each
time the vehicle is started.
Rear Camera Mirror
If equipped, this automatic dimming
mirror provides a wide angle camera
view of the area behind the vehicle.
Pull the tab to turn on the display.
Push the tab to turn it off. When off
the mirror is automatic dimming.
Adjust the mirror for a clear view of
the area behind the vehicle while
the display is off.
PressVto scroll through the
adjustment options.
Press
tanduto adjust the
settings using the indicators on the
mirror. The indicators will remain
visible for five seconds after the last
button activation, and the settings
will remain saved.
The adjustment options are:

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 63
The temperature performance of an
unoccupied seat may be reduced.
This is normal.
The heated or ventilated seats will
not turn on during a remote start
unless they are enabled in vehicle
personalization. SeeRemote
Vehicle Start 024 and
Vehicle Personalization 0157.Rear Seats
Rear Seat Reminder
If equipped, the message REAR
SEAT REMINDER LOOK IN REAR
SEAT 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.
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.
See
Vehicle Personalization 0157.
Folding the Rear Seat Cushion
Either side of the rear seat cushion
can be folded up for added cargo
space.
Caution
Folding 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 69
feature stays engaged after
letting the belt go back to
stowed position on the seat,
move the seat rearward or
recline the seat until the
shoulder belt retractor lock
releases.
Engaging the child restraint
locking feature in the front
outboard seating position may
affect the passenger sensing
system, if equipped. See
Passenger Sensing System
078.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 071.
Position the release button on
the buckle so that the seat belt
could be quickly unbuckled if
necessary.
4. To make the lap part tight, pull up on the shoulder belt.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
70 Seats and Restraints
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.
Seat Belt Pretensioners
This vehicle has seat belt
pretensioners for the 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 pretensioneractivation are met. Seat belt
pretensioners can also help tighten
the seat belts in a side crash or
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 072.
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
comfort guides.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Seats and Restraints 77
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? 074.
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? 076.
Airbags should never be regarded
as anything more than a supplement
to seat belts.
What Will You See after
an Airbag Inflates?
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? 074.
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.
{Warning
When an airbag inflates, there
may be dust in the air. This dust
could cause breathing problems
for people with a history of
asthma or other breathing trouble.
To avoid this, everyone in the
vehicle should get out as soon as
it is safe to do so. If you have
breathing problems but cannot
get out of the vehicle after an
airbag inflates, then get fresh air
by opening a window or a door.
If you experience breathing
problems following an airbag
deployment, you should seek
medical attention.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
82 Seats and Restraints
2. Remove any additional materialfrom the seat, such as
blankets, cushions, seat
covers, seat heaters, or seat
massagers.
3. Place the seatback in the fully upright position.
4. Have the person sit upright in the seat, centered on the seat
cushion, with legs comfortably
extended.
5. If the shoulder portion of the belt is pulled out all the way,
the child restraint locking
feature will be engaged. This
may unintentionally cause the
passenger sensing system to
turn the airbag off for some
adult-sized occupants. If this
happens, unbuckle the belt, let
the belt go back all the way,
and then buckle the belt again
without pulling the belt out all
the way.
6. Restart the vehicle and have the person remain in this
position for two to three minutes
after the ON indicator is lit.{Warning
If the front outboard passenger
airbag is turned off for an
adult-sized occupant, the airbag
will not be able to inflate and help
protect that person in a crash,
resulting in an increased risk of
serious injury or even death. An
adult-sized occupant should not
ride in the front outboard
passenger seat, if the passenger
airbag OFF indicator is lit.
Additional Factors Affecting
System Operation
Seat belts help keep the passenger
in position on the seat during
vehicle maneuvers and braking,
which helps the passenger sensing
system maintain the passenger
airbag status. See “Seat Belts”and
“Child Restraints” in the Index for
additional information about the
importance of proper restraint use. 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 083
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)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
86 Seats and Restraints
Q: What is the proper way towear seat 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 Seat Belt Comfort
Guides” underLap-Shoulder Belt
0 68.
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 seat belts
properly.{Warning
Never allow more than one child
to wear the same seat belt. The
seat belt cannot properly spread
the impact forces. In a crash, they
can be crushed together and
seriously injured. A seat belt must
be used by only one person at
a time.
{Warning
Never allow a child to wear the
seat 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 99
Warning (Continued)
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.
Caution
Do not let the LATCH
attachments rub against the
vehicle’s seat belts. This may(Continued)
Caution (Continued)
damage these parts. If necessary,
move buckled seat belts to avoid
rubbing the LATCH attachments.
Do not fold the rear seat cushion
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 091.
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 (In
the Center Front Seat) 0108 or Securing Child Restraints (With
the Seat Belt in the Rear Seat)
0
105 or
Securing Child Restraints (With
the Seat Belt in the Front
Outboard Seat) 0109.
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:
1.1. Find the top tether anchor.
1.2. Route, attach, and tighten the top tether according
to your child restraint
instructions and the
following instructions:

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Seats and Restraints 107
7. For forward-facing childrestraints, 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) 092.
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 head restraint or
headrest before the seating position
is used. See “Head Restraint or
Headrest Removal and Reinstallation”
underLower Anchors
and Tethers for Children (LATCH
System) 092 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 seat belt through
or around the child restraint.
The child restraint instructions
will show you how.
3. Push the latch plate into thebuckle until it clicks.
Position the release button on
the buckle, away from the child
restraint, 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.