
GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 69
{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 069 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 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 Publication Ordering
Information 0435.
{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 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, including
improperly repairing or replacing, any parts
of the following:
.Airbag system, including airbag modules,
front or side impact sensors, sensing and
diagnostic module, or airbag wiring

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 73
Warning (Continued)
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.
Never leave children unattended in a
vehicle and never allow children to play
with the seat belts.
Every time infants and young children ride
in vehicles, they should have the protection
provided by appropriate child restraints.
Neither the vehicle's seat belt system nor its
airbag system is designed for them.
Children who are not restrained properly can
strike other people, or can be thrown out of
the vehicle.
{Warning
Never hold an infant or a child while
riding in a vehicle. Due to crash forces, an
infant or a child will become so heavy it
is not possible to hold it during a crash.
For example, in a crash at only
40 km/h (25 mph), a 5.5 kg (12 lb) infant
will suddenly become a 110 kg (240 lb)
force on a person's arms. An infant or
child should be secured in an appropriate
child restraint.
{Warning
Children who are up against, or very
close to, any airbag when it inflates can
be seriously injured or killed. Never put a
rear-facing child restraint in the front
outboard seat. Secure a rear-facing child
restraint in a rear seat. It is also better to
secure a forward-facing child restraint in
a rear seat. If you must secure a
forward-facing child restraint in the front
outboard seat, always move the front
passenger seat as far back as it will go.
Child restraints are devices used to restrain,
seat, or position children in the vehicle and
are sometimes called child seats or car seats.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 77
{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.
Do not use child restraints in the center
front seat position.
If the vehicle does not have a rear seat that
will accommodate a rear-facing child
restraint, a rear-facing child restraint should
not be installed in the vehicle, even if the
airbag is off.
When securing a child restraint with the
seat belts in a rear seat position, study the
instructions that came with the child
restraint to make sure it is compatible with
this vehicle.
Child restraints and booster seats vary
considerably in size, and some may fit in
certain seating positions better than others.
Do not install a child restraint in any rear
seating position where it cannot be installed
securely. Depending on where you place the child
restraint and the size of the child restraint,
you may not be able to access adjacent seat
belts or LATCH anchors for additional
passengers or child restraints. Adjacent
seating positions should not be used if the
child restraint prevents access to or
interferes with the routing of the seat belt.
The seat in front of an installed child
restraint should be adjusted to ensure
proper installation according to the child
restraint manual.
Wherever a child restraint is installed, be
sure to follow the instructions that came
with the child restraint and secure the child
restraint properly.
Keep in mind that an unsecured child
restraint can move around in a collision or
sudden stop and injure people in the vehicle.
Be sure to properly secure any child
restraint in the vehicle
—even when no
child is in it.
Lower Anchors and Tethers for
Children (LATCH System)
The LATCH system secures a child restraint
during driving or in a crash. LATCH
attachments on the child restraint are used
to attach the child restraint to the anchors
in the vehicle. This system is designed to
make installation of a child restraint easier.
In order to use the LATCH system in your
vehicle, you need a child restraint that has
LATCH attachments. LATCH-compatible
rear-facing and forward-facing child seats can
be properly installed using either the LATCH
anchors or the vehicle’s seat belts. Do not
use both the seat belts and the LATCH
anchorage system to secure a rear-facing or
forward-facing child seat.
Booster seats use the vehicle’s seat belts to
secure the child and the booster seat. If the
manufacturer recommends that the booster
seat be secured with the LATCH system, this
can be done as long as the booster seat can
be positioned properly and there is no
interference with the proper positioning of
the lap-shoulder belt on the child.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 79
Recommended Methods for Attaching Child Restraints
Restraint Type Combined Weight ofthe Child + Child
Restraint Use Only Approved Attachment Methods Shown with an X
LATCH
–Lower
Anchors Only Seat Belt Only LATCH
–Lower
Anchors and Top
Tether Anchor Seat Belt and Top
Tether Anchor
Rear-Facing Child
Restraint Up to 29.5 kg (65 lb)
X X
Rear-Facing Child
Restraint Greater than
29.5 kg (65 lb) X
Forward-Facing Child
Restraint Up to 29.5 kg (65 lb)
X X
Forward-Facing Child
Restraint Greater than
29.5 kg (65 lb) X
See Securing Child Restraints (With the Seat
Belt in the Center Front Seat) 092 or
Securing Child Restraints (With the Seat Belt
in the Rear Seat) 088 or
Securing Child Restraints (With the Seat Belt
in the Front Passenger Seat) 092. Child restraints built after March 2014 will
be labeled with the specific child weight up
to which the LATCH system can be used to
install the restraint.
The following explains how to attach a child
restraint with these attachments in the
vehicle. Not all vehicle seating positions have lower
anchors. In this case, the seat belt must be
used (with top tether where available) to
secure the child restraint. See
Securing Child
Restraints (With the Seat Belt in the Center
Front Seat) 092 or
Securing Child Restraints (With the Seat Belt
in the Rear Seat) 088 or
Securing Child Restraints (With the Seat Belt
in the Front Passenger Seat) 092.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
84 Seats and Restraints
Regular Cab Models1. 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) 092 or
Securing Child Restraints (With the Seat
Belt in the Rear Seat) 088 or
Securing Child Restraints (With the Seat
Belt in the Front Passenger Seat) 092.
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:
If the position you are using has an
adjustable head restraint and you
are using a dual tether, route the
tether around the head restraint.
If the position you are using has an
adjustable head restraint and you
are using a single tether, raise the
head restraint and route the tether
under the head restraint and in
between the head restraint posts. 2. Make sure the child restraint top tether
hook is completely closed and secured to
the top tether anchor.
3. Secure the child restraint in the right front seating position with the vehicle
belts. See Securing Child Restraints (With
the Seat Belt in the Center Front Seat)
0 92 or
Securing Child Restraints (With the Seat
Belt in the Rear Seat) 088 or
Securing Child Restraints (With the Seat
Belt in the Front Passenger Seat) 092.
4. Before placing a child in the child restraint, make sure it is securely held in
place. To check, grasp the child restraint
at the belt path and attempt to move it
side to side and back and forth. There
should be no more than 2.5 cm (1 in) of
movement for proper installation.
Double and Crew Cab Models 1. Attach and tighten the lower attachments to the lower anchors. If the
child restraint does not have lower
attachments or the desired seating
position does not have lower anchors,
secure the child restraint with the top
tether and the seat belt. Refer to the
child restraint manufacturer instructions
and the instructions in this manual.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Instruments and Controls 101
seats when it is cold outside. The heated
steering wheel indicator light may not
come on.
SeeHeated and Ventilated Front Seats 052.
Horn
To sound the horn, pressaon the
steering wheel.
Windshield Wiper/Washer
The windshield wiper control is on the turn
signal lever.
The windshield wipers are controlled by
turning the band with
Non it.
With the ignition on or in ACC/ACCESSORY,
turn the
Nband to select the wiper speed.
HI : Use for fast wipes. LO :
Use for slow wipes.
3:Turn the band up for more frequent
intermittent wipes or down for less frequent
intermittent wipes.
OFF : Use to turn the wipers off.
1x : For a single wipe, briefly turn the
N
band down. For several wipes, hold the
band down.
L:PressLon the windshield wiper
control to spray windshield washer fluid and
activate the wipers. The wipers will continue
until
Lis released or the maximum wash
time is reached. When
Lis released,
additional wipes may occur depending on
how long the windshield washer had been
activated. See Washer Fluid0340 for
information on filling the windshield washer
fluid reservoir.
Clear snow and ice from the wiper blades
before using them. If frozen to the
windshield, carefully loosen or thaw them.
Damaged blades should be replaced. See
Wiper Blade Replacement 0348.
Heavy snow or ice can overload the wiper
motor.
{Warning
In freezing weather, do not use the
washer until the windshield is warmed.
Otherwise the washer fluid can form ice
on the windshield, blocking your vision.
{Warning
Before driving the vehicle, always clear
snow and ice from the hood, windshield,
roof, and rear of the vehicle, including all
lamps and windows. Reduced visibility
from snow and ice buildup could lead to
a crash.
Wipe Parking
If the ignition is turned off while the wipers
are on LO, HI, or
3, they will
immediately stop.
If the windshield wiper control is ON then
moved to OFF before the driver door is
opened or within 10 minutes, the wipers will
restart and move to the base of the
windshield.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
102 Instruments and Controls
If the ignition is turned off while the wipers
are performing wipes due to windshield
washing, the wipers continue to run until
they reach the base of the windshield.
Compass
The vehicle may have a compass display on
the Driver Information Center (DIC). The
compass receives its heading and other
information from the Global Positioning
System (GPS) antenna, Electronic Stability
Control (ESC), and vehicle speed information.
The compass system is designed to operate
for a certain number of miles or degrees of
turn before needing a signal from the GPS
satellites. When the compass display shows
CAL, drive the vehicle for a short distance in
an open area where it can receive a GPS
signal. The compass system will
automatically determine when a GPS signal
is restored and provide a heading again.
Clock
Set the time and date using the
infotainment system. See "Time / Date"
underSettings 0186.
Power Outlets
Accessory power outlets can be used to plug
in electrical equipment, such as a cell phone
or MP3 player.
Rear of Front Center Console
The vehicle has one accessory power outlet
under the climate control system and one
accessory power outlet on the rear of the
center console, if equipped, or on the rear of
the bench seat, if equipped.
Lift the cover to access and replace when
not in use.
{Warning
Power is always supplied to the outlets.
Do not leave electrical equipment
plugged in when the vehicle is not in use
because the vehicle could catch fire and
cause injury or death.
Caution
Leaving electrical equipment plugged in
for an extended period of time while the
vehicle is off will drain the battery.
Always unplug electrical equipment when
not in use and do not plug in equipment
that exceeds the maximum 15 amp
rating.
Certain power accessory plugs may not be
compatible with the accessory power outlet
and could overload vehicle or adapter fuses.
If a problem is experienced, see your dealer.
When adding electrical equipment, be sure
to follow the proper installation instructions
included with the equipment. See Add-On
Electrical Equipment 0318.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Instruments and Controls 113
Voltmeter Gauge
Uplevel Shown, Base Level and MidlevelSimilar
When the ignition is on, this gauge indicates
the battery voltage.
When the engine is running, this gauge
shows the condition of the charging system.
The gauge can transition from a higher to
lower or a lower to higher reading. This is
normal. If the vehicle is operating outside
the normal operating range, the charging
system light comes on. See Charging System
Light 0115. The voltmeter gauge may also
read lower when in fuel economy mode.
This is normal. Readings outside the normal operating
range can also occur when a large number
of electrical accessories are operating in the
vehicle and the engine is left idling for an
extended period. This condition is normal
since the charging system is not able to
provide full power at engine idle. As engine
speeds are increased, this condition should
correct itself as higher engine speeds allow
the charging system to create maximum
power.
The vehicle can only be driven for a short
time with the readings outside the normal
operating range. If the vehicle must be
driven, turn off all accessories, such as the
radio and air conditioner.
Readings outside the normal operating
range indicate a possible problem in the
electrical system. Have the vehicle serviced
as soon as possible.
Seat Belt Reminders
Driver Seat Belt Reminder Light
There is a driver seat belt reminder light on
the instrument cluster.
When the vehicle is started, this light
flashes and a chime may come on to remind
the driver to fasten their seat belt.
Then the light stays on solid until the belt is
buckled. This cycle may continue several
times if the driver remains or becomes
unbuckled while the vehicle is moving.
If the driver seat belt is buckled, neither the
light nor the chime comes on.
Front Passenger Seat Belt Reminder
Light
The vehicle may have a front passenger seat
belt reminder light near the passenger
airbag status indicator. See
Passenger
Sensing System 066.