
GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
62 Seats and Restraints
Warning (Continued)
crash. Always wear a seat belt, even with
airbags. The driver should sit as far back
as possible while still maintaining control
of the vehicle. The seat belts and the
front outboard passenger airbags are
most effective when you are sitting well
back and upright in the seat with both
feet on the floor.
Occupants should not lean on or sleep
against the door or side windows in
seating positions with seat-mounted side
impact airbags and/or roof-rail airbags.
{Warning
Children who are up against, or very
close to, any airbag when it inflates can
be seriously injured or killed. Always
secure children properly in the vehicle. To
read how, seeOlder Children 071 or
Infants and Young Children 072.
There is an airbag readiness light on the
instrument cluster, which shows the airbag
symbol.
The system checks the airbag electrical
system for malfunctions. The light tells you
if there is an electrical problem. See Airbag
Readiness Light 0114.
Where Are the Airbags?
The driver frontal airbag is in the center of
the steering wheel.
The front outboard passenger frontal airbag
is in the passenger side instrument panel.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 63
Driver Side Shown, Passenger Side Similar
The driver and front outboard passenger
seat-mounted side impact airbags are in the
side of the seatbacks closest to the door.Driver Side Crew Cab Shown, Passenger Side Double and Regular Cabs Similar
The roof-rail airbags for the driver, front
outboard passenger, and second row
outboard passengers are in the ceiling above
the side windows.
{Warning
If something is between an occupant and
an airbag, the airbag might not inflate
properly or it might force the object into
that person causing severe injury or even
death. The path of an inflating airbag
must be kept clear. Do not put anything
between an occupant and an airbag, and (Continued)
Warning (Continued)
do not attach or put anything on the
steering wheel hub or on or near any
other airbag covering.
Do not use seat accessories that block the
inflation path of a seat-mounted side
impact airbag.
Never secure anything to the roof of a
vehicle with roof-rail airbags by routing a
rope or tie‐down through any door or
window opening. If you do, the path of
an inflating roof-rail airbag will be
blocked.
When Should an Airbag Inflate?
This vehicle is equipped with airbags. See
Airbag System061. Airbags are designed to
inflate if the impact exceeds the specific
airbag system's deployment threshold.
Deployment thresholds are used to predict
how severe a crash is likely to be in time
for the airbags to inflate and help restrain
the occupants. The vehicle has electronic
sensors that help the airbag system
determine the severity of the impact.
Deployment thresholds can vary with
specific vehicle design.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
64 Seats and Restraints
Frontal airbags are designed to inflate in
moderate to severe frontal or near frontal
crashes to help reduce the potential for
severe injuries, mainly to the driver's or
front outboard passenger's head and chest.
Whether the frontal airbags will or should
inflate is not based primarily on how fast
the vehicle is traveling. It depends on what
is hit, the direction of the impact, and how
quickly the vehicle slows down.
Frontal airbags may inflate at different crash
speeds depending on whether the vehicle
hits an object straight on or at an angle,
and whether the object is fixed or moving,
rigid or deformable, narrow or wide.
Frontal airbags are not intended to inflate
during vehicle rollovers, rear impacts,
or many side impacts.
In addition, the vehicle has advanced
technology frontal airbags. Advanced
technology frontal airbags adjust the
restraint according to crash severity.
Seat-mounted side impact airbags are
designed to inflate in moderate to severe
side crashes depending on the location of
the impact. Seat-mounted side impact
airbags are not designed to inflate in frontal
impacts, near frontal impacts, rollovers,or rear impacts. A seat-mounted side impact
airbag is designed to inflate on the side of
the vehicle that is struck.
Roof-rail airbags are designed to inflate in
moderate to severe side crashes depending
on the location of the impact. In addition,
these roof-rail airbags are designed to inflate
during a rollover or in a severe frontal
impact. Roof-rail airbags are not designed to
inflate in rear impacts. Both roof-rail airbags
will inflate when either side of the vehicle is
struck or if the sensing system predicts that
the vehicle is about to roll over on its side,
or in a severe frontal impact.
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? 062.
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 63.
Airbags should never be regarded as
anything more than a supplement to seat
belts.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 65
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, seeWhere Are the Airbags? 062.
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 (Continued)
Warning (Continued)
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.
The vehicle has a feature that may
automatically unlock the doors, turn on the
interior lamps and hazard warning flashers,
and shut off the fuel system after the
airbags inflate. The feature may also
activate, without airbag inflation, after an
event that exceeds a predetermined
threshold. After turning the ignition off and
then on again, the fuel system will return to
normal operation; the doors can be locked,
the interior lamps can be turned off, and
the hazard warning flashers can be turned
off using the controls for those features.
If any of these systems are damaged in the
crash they may not operate as normal.
{Warning
A crash severe enough to inflate the
airbags may have also damaged
important functions in the vehicle, such
as the fuel system, brake and steering
systems, etc. Even if the vehicle appears
to be drivable after a moderate crash,
there may be concealed damage that
could make it difficult to safely operate
the vehicle.
Use caution if you should attempt to
restart the engine after a crash has
occurred.
In many crashes severe enough to inflate
the airbag, windshields are broken by
vehicle deformation. Additional windshield
breakage may also occur from the front
outboard passenger airbag.
.Airbags are designed to inflate only once.
After an airbag inflates, you will need
some new parts for the airbag system.
If you do not get them, the airbag
system will not be there to help protect
you in another crash. A new system will
include airbag modules and possibly other
parts. The service manual for the vehicle
covers the need to replace other parts.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
70 Seats and Restraints
.Front seats, including stitching, seams,
or zippers
.Seat belts
.Steering wheel, instrument panel,
overhead console, ceiling trim, or pillar
garnish trim
.Inner door seals, including speakers
Your dealer and the service manual have
information about the location of the airbag
modules and sensors, sensing and diagnostic
module, and airbag wiring along with the
proper replacement procedures.
In addition, the vehicle has a passenger
sensing system for the front outboard
passenger position, which includes sensors
that are part of the passenger seat. The
passenger sensing system may not operate
properly if the original seat trim is replaced
with non-GM covers, upholstery, or trim; or
with GM covers, upholstery, or trim
designed for a different vehicle. Any object,
such as an aftermarket seat heater or a
comfort-enhancing pad or device, installed
under or on top of the seat fabric, could
also interfere with the operation of the
passenger sensing system. This could either
prevent proper deployment of the passenger
airbag(s) or prevent the passenger sensing system from properly turning off the
passenger airbag(s). See
Passenger Sensing
System 066.
If the vehicle has rollover roof-rail airbags,
see Different Size Tires and Wheels 0377 for
additional important information.
If a snow plow is added to the vehicle, the
airbags should still work properly. The
airbag systems were designed to work
properly under a wide range of conditions,
including snow plowing with vehicles that
have the optional snow plow prep package
(RPO VYU). Do not change or defeat the
snow plow's “tripping mechanism.” If you
do, it can damage the snow plow and the
vehicle, and may cause an airbag
deployment.
If the vehicle must be modified because you
have a disability and have questions about
whether the modifications will affect the
vehicle's airbag system, or if you have
questions about whether the airbag system
will be affected if the vehicle is modified for
any other reason, call Customer Assistance.
See Customer Assistance Offices 0430.
Airbag System Check
The airbag system does not need regularly
scheduled maintenance or replacement.
Make sure the airbag readiness light is
working. See Airbag Readiness Light 0114.
Caution
If an airbag covering is damaged, opened,
or broken, the airbag may not work
properly. Do not open or break the airbag
coverings. If there are any opened or
broken airbag coverings, have the airbag
covering and/or airbag module replaced.
For the location of the airbags, see Where
Are the Airbags? 062. See your dealer
for service.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Instruments and Controls 99
Instruments and Controls
Controls
Steering Wheel Adjustment . . . . . . . . . . . 100
Steering Wheel Controls . . . . . . . . . . . . . . 100
Heated Steering Wheel . . . . . . . . . . . . . . . . 100
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Windshield Wiper/Washer . . . . . . . . . . . . . 101
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Power Outlets . . . . . . . . . . . . . . . . . . . . . . . . . 102
Wireless Charging . . . . . . . . . . . . . . . . . . . . . 103
Warning Lights, Gauges, and Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Instrument Cluster . . . . . . . . . . . . . . . . . . . . 106
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . . 110
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Fuel Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Engine Oil Pressure Gauge . . . . . . . . . . . . . 111
Engine Coolant Temperature Gauge . . . . 112
Voltmeter Gauge . . . . . . . . . . . . . . . . . . . . . . . 113
Seat Belt Reminders . . . . . . . . . . . . . . . . . . . . 113
Airbag Readiness Light . . . . . . . . . . . . . . . . . 114
Passenger Airbag Status Indicator . . . . . . 114
Charging System Light . . . . . . . . . . . . . . . . . 115 Malfunction Indicator Lamp (Check
Engine Light) . . . . . . . . . . . . . . . . . . . . . . . . . 115
Brake System Warning Light . . . . . . . . . . . 117
Electric Parking Brake Light . . . . . . . . . . . . 117
Service Electric Parking Brake Light . . . . 118
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Four-Wheel-Drive Light . . . . . . . . . . . . . . . . . 118
Tow/Haul Mode Light . . . . . . . . . . . . . . . . . 119
Hill Descent Control Light . . . . . . . . . . . . . . 119
Lane Keep Assist (LKA) Light . . . . . . . . . . . 119
Vehicle Ahead Indicator . . . . . . . . . . . . . . . . 119
Pedestrian Ahead Indicator . . . . . . . . . . . . 119
Traction Off Light . . . . . . . . . . . . . . . . . . . . . . 120
Traction Control System (TCS)/Electronic Stability Control Light . . . . . . . . . . . . . . . 120
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Driver Mode Control Light . . . . . . . . . . . . . 121
Tire Pressure Light . . . . . . . . . . . . . . . . . . . . . 122
Engine Oil Pressure Light (Uplevel Cluster) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Low Fuel Warning Light . . . . . . . . . . . . . . . . 122
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . 122
High-Beam On Light . . . . . . . . . . . . . . . . . . . 123
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . 123
Lamps On Reminder . . . . . . . . . . . . . . . . . . . 123
Cruise Control Light . . . . . . . . . . . . . . . . . . . . 123 Door Ajar Light . . . . . . . . . . . . . . . . . . . . . . . . 124
Information Displays
Driver Information Center (DIC) (Base
Level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Driver Information Center (DIC) (Midlevel and Uplevel) . . . . . . . . . . . . . . . 125
Head-Up Display (HUD) . . . . . . . . . . . . . . . . 128
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . . . . . . . . . . . 130
Engine Power Messages . . . . . . . . . . . . . . . . 131
Vehicle Speed Messages . . . . . . . . . . . . . . . 131
Vehicle Personalization
Vehicle Personalization . . . . . . . . . . . . . . . . . 131
Universal Remote System
Universal Remote System . . . . . . . . . . . . . 136
Universal Remote System Programming . . . . . . . . . . . . . . . . . . . . . . . . 136
Universal Remote System Operation . . . 138

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
100 Instruments and Controls
Controls
Steering Wheel Adjustment
To adjust the steering wheel:1. Pull the lever down.
2. Move the steering wheel up or down.
3. Pull the lever up to lock the steering wheel in place. Tilt and Telescoping Wheel
To adjust the tilt and telescoping steering
wheel, if equipped:
1. Pull the lever down.
2. Move the steering wheel up or down.
3. Pull or push the steering wheel closer or away from you.
4. Pull the lever up to lock the steering wheel in place.
Do not adjust the steering wheel while
driving.
Steering Wheel Controls
The infotainment system can be operated
by using the steering wheel controls. See
Steering Wheel Controls 0151.
Heated Steering Wheel
(:If equipped, press to turn it on or off.
A light next to the button displays when the
feature is turned on.
The steering wheel takes about
three minutes to start heating.
Remote Start Heated Steering Wheel
If equipped with remote start, the heated
steering wheel will turn on automatically
during a remote start along with the heated

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
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.