2021 GMC SIERRA Radio signals

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Instruments and Controls 137
Programming the Universal Remote
System
For questions or programming help, see
www.homelink.com/gm or call
1-800-355-3515. For calls placed outside the
U.S., Canada, or Puerto Rico, international
rates will apply and may differ based on
landline or mobile phone.
Programming involves time-sensitive actions,
and may time out causing the procedure to
be repeated.
To program up to three devices:1. Hold the end of the hand-held transmitter about 3 to 8 cm (1 to 3 in)
away from the Universal Remote system
buttons with the indicator light in view.
The hand-held transmitter was supplied
by the manufacturer of the garage door
opener receiver.
2. Press and release one of the three Universal Remote system buttons to be
programmed. Press and hold the
hand-held transmitter button. Do not
release the hand-held transmitter button
until the indicator light changes from a
slow to a rapid flash or continuous light.
Then release the hand-held transmitter
button. Some garage door openers may require
substitution of Step 2 with the procedure
under
“Radio Signals for Some Gate
Operators” later in this section.
3. Press and hold the newly programmed Universal Remote system button for
five seconds while watching the indicator
light and garage door activation.
.If the indicator light stays on
continuously or the garage door
moves when the button is pressed,
then programming is complete. There
is no need to complete Steps 4–6.
.If the indicator light does not come
on or the garage door does not
move, a second button press may be
required. For a second time, press
and hold the newly programmed
button for five seconds. If the
indicator light is continuously lit,
or the garage door moves,
programming is complete.
.If the indicator light flashes rapidly
and the garage door does not move,
continue with programming
Steps 4–6.
Learn or Smart Button
4. After completing Steps 1–3, locate the Learn or Smart button inside the garage
on the garage door opener receiver. The
name and color of the button may vary
by manufacturer.
5. Press and release the Learn or Smart button. Step 6 must be completed within
30 seconds of pressing this button.
6. Return to the vehicle and firmly press and hold the trained Universal Remote
system button for two seconds and
release. Repeat the “press/hold/release”
sequence up to three times to complete
the training process.
The Universal Remote system should now
activate the garage door.
Repeat the process for programming the
two remaining buttons.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
138 Instruments and Controls
Radio Signals for Some Gate Operators
For questions or programming help, see
www.homelink.com/gm or call
1-800-355-3515. For calls placed outside the
U.S., Canada, or Puerto Rico, international
rates will apply and may differ based on
landline or mobile phone.
Some radio–frequency laws and gate
operators require transmitter signals to time
out or quit after several seconds of
transmission. This may not be long enough
for the Universal Remote system to pick up
the signal during programming.
If the programming did not work, replace
Step 2 under“Programming the Universal
Remote System” with the following:
Press and hold the Universal Remote system
button while pressing and releasing the
hand-held transmitter button every
two seconds until the signal has been
successfully accepted by the Universal
Remote system. The Universal Remote
system indicator light will flash slowly at
first and then change to a rapid flash or
continuous solid-light. Proceed with Step 3
under “Programming the Universal Remote
System” to complete.
Universal Remote System
Operation
Using the Universal Remote System
Press and hold the appropriate Universal
Remote system button for at least one-half
second. The indicator light will come on
while the signal is being transmitted.
Erasing Universal Remote System
Buttons
Erase all programmed buttons when vehicle
ownership is terminated.
To erase:
1. Press and hold the two outside buttons until the indicator light begins to flash.
This should take about 10 seconds.
2. Release both buttons.
Reprogramming a Single Universal
Remote System Button
To reprogram any of the system buttons: 1. Press and hold any one of the buttons. Do not release the button.
2. The indicator light will begin to flash after 20 seconds. Without releasing the
button, proceed with Step 1 under
“Programming the Universal Remote
System.”

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
158 Infotainment System
by model and require a complete working
electrical system, cell reception, and GPS
signal. An active connected plan is required.
Reference the SiriusXM user guide for use
and subscription information.
Radio Reception
Unplug electronic devices from the accessory
power outlets if there is interference or
static in the radio.
FM
FM signals only reach about 16 to 65 km (10
to 40 mi). Although the radio has a built-in
electronic circuit that automatically works to
reduce interference, some static can occur,
especially around tall buildings or hills,
causing the sound to fade in and out.
AM
The range for most AM stations is greater
than for FM, especially at night. The longer
range can cause station frequencies to
interfere with each other. Static can also
occur when things like storms and power
lines interfere with radio reception. When
this happens, try reducing the treble on the
radio.
SiriusXM Satellite Radio Service
If equipped, SiriusXM Satellite Radio Service
provides digital radio reception. Tall
buildings or hills can interfere with satellite
radio signals, causing the sound to fade in
and out. In addition, traveling or standing
under heavy foliage, bridges, garages,
or tunnels may cause loss of the SiriusXM
signal for a period of time. Some cellular
services may interfere with SXM reception
causing loss of signal.
Mobile Device Usage
Mobile device usage, such as making or
receiving calls, charging, or just having the
mobile device on may cause static
interference in the radio. Unplug the mobile
device or turn it off if this happens.
Fixed Mast Antenna
The fixed mast antenna will go through
most car washes as long as it is securely
attached. If the antenna becomes slightly
bent, straighten it out by hand. If it is badly
bent, replace it.
Occasionally check that the antenna is tight
at the base. If tightening is required, protect
the paint from damage.
Multi-Band Antenna
The roof antenna is for SiriusXM Satellite
Radio, OnStar, and GPS (Global Positioning
System), depending on the equipped
options. Keep clear of obstructions for clear
reception. If the vehicle has a sunroof, and it
is open, reception can also be affected.
Audio Players
Avoiding Untrusted Media Devices
When using media devices such as SD cards,
USB devices, and mobile devices, consider
the source. Untrusted media devices could
contain files that affect system operation or
performance. Avoid use if the content or
origin cannot be trusted.
USB Port
This vehicle is equipped with two USB ports
in the center console under the armrest and
another two in the center stack. These ports
are for data and charging.
There may also be two USB ports for
charging only at the rear of the center
console.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
442 OnStar
Reactivation for Subsequent Owners
PressQand follow the prompts to speak to
an Advisor as soon as possible. The Advisor
will update vehicle records and explain
OnStar or connected service options.
How OnStar Service Works
Automatic Crash Response, Emergency
Services, Crisis Assist, Stolen Vehicle
Assistance, Remote Services, and Roadside
Assistance are available on most vehicles.
Not all OnStar services are available
everywhere or on all vehicles. For more
information, a full description of OnStar
services, system limitations, and OnStar User
Terms, Privacy Statement, and Software
Terms:
.Call 1-888-4ONSTAR (1-888-466-7827).
.See www.onstar.com (U.S.).
.See www.onstar.ca (Canada).
.Call TTY 1-877-248-2080.
.PressQto speak with an Advisor.
OnStar or connected services cannot work
unless the vehicle is in a place where OnStar
has an agreement with a wireless service
provider for service in that area. The
wireless service provider must also have
coverage, network capacity, reception, and technology compatible with OnStar or
connected services. Service involving location
information about the vehicle cannot work
unless GPS signals are available,
unobstructed, and compatible with the
OnStar hardware. OnStar or connected
services may not work if the OnStar
equipment is not properly installed or it has
not been properly maintained. If equipment
or software is added, connected,
or modified, OnStar or connected services
may not work. Other problems beyond the
control of OnStar
—such as hills, tall
buildings, tunnels, weather, electrical system
design and architecture of the vehicle,
damage to the vehicle in a crash, or wireless
phone network congestion or jamming —
may prevent service.
See Radio Frequency Statement 0436.
Services for People with Disabilities
Advisors provide services to help with
physical disabilities and medical conditions.
Press
Qto help:
.Locate a gas station with an attendant to
pump gas.
.Find a hotel, restaurant, etc., that meets
accessibility needs.
.Provide directions to the closest hospital
or pharmacy in urgent situations.
TTY Users
OnStar has the ability to communicate to
deaf, hard-of-hearing, or speech-impaired
customers while in the vehicle. The available
dealer-installed TTY system can provide
in-vehicle access to all OnStar services,
except Virtual Advisor and OnStar
Turn-by-Turn Navigation.
If equipped, TTY mode can be turned on or
off by touching Settings, then Apps, and
then Phone. When TTY mode is on, phone
calls can be made or received with OnStar
using the infotainment display.
OnStar Personal Identification
Number (PIN)
A PIN is needed to access some OnStar
services. The PIN will need to be changed
the first time when speaking with an
Advisor. To change the OnStar PIN, contact
an OnStar Advisor by pressing
Qor calling
1-888-4ONSTAR.
Warranty
OnStar equipment may be warranted as part
of the vehicle warranty.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
OnStar 443
Languages
The vehicle can be programmed to respond
in multiple languages. Press
Qand ask for
an Advisor. Advisors are available in English,
Spanish, and French. Available languages
may vary by country.
Potential Issues
OnStar cannot perform Remote Door Unlock
or Stolen Vehicle Assistance after the vehicle
has been off continuously for 10 days
without an ignition cycle. If the vehicle has
not been started for 10 days, OnStar can
contact Roadside Assistance or a locksmith
to help gain access to the vehicle.
Global Positioning System (GPS)
.Obstruction of the GPS can occur in a
large city with tall buildings; in parking
garages; around airports; in tunnels and
underpasses; or in an area with very
dense trees. If GPS signals are not
available, the OnStar system should still
operate to call OnStar. However, OnStar
could have difficulty identifying the exact
location.
.In emergency situations, OnStar can use
the last stored GPS location to send to
emergency responders. A temporary loss of GPS can cause loss of
the ability to send a Turn-by-Turn
Navigation route. The Advisor may give a
verbal route or may ask for a call back after
the vehicle is driven into an open area.
Cellular and GPS Antennas
Cellular reception is required for OnStar to
send remote signals to the vehicle. Do not
place items over or near the antenna to
prevent blocking cellular and GPS signal
reception.
Unable to Connect to OnStar Message
If there is limited cellular coverage or the
cellular network has reached maximum
capacity, this message may come on. Press
Qto try the call again or try again after
driving a few miles into another
cellular area.
Vehicle and Power Issues
OnStar services require a vehicle electrical
system, wireless service, and GPS satellite
technologies to be available and operating
for features to function properly. These
systems may not operate if the battery is
discharged or disconnected.
Add-on Electrical Equipment
The OnStar system is integrated into the
electrical architecture of the vehicle. Do not
add any electrical equipment. See Add-On
Electrical Equipment 0318. Added electrical
equipment may interfere with the operation
of the OnStar system and cause it to not
operate.
Vehicle Software Updates
OnStar or GM may remotely deliver
software updates or changes to the vehicle
without further notice or consent. These
updates or changes may enhance or
maintain safety, security, or the operation
of the vehicle or the vehicle systems.
Software updates or changes may affect or
erase data or settings that are stored in the
vehicle, such as saved navigation
destinations or pre-set radio stations.
Neither OnStar nor GM is responsible for
any affected or erased data or settings.
These updates or changes may also collect
personal information. Such collection is
described in the OnStar privacy statement or
separately disclosed at the time of
installation. These updates or changes may
also cause a system to automatically
communicate with GM servers to collect
information about vehicle system status,

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
Index 457
S
Safety Defects ReportingCanadian Government . . . . . . . . . . . . . . . . . 437
General Motors . . . . . . . . . . . . . . . . . . . . . . . . 437
U.S. Government . . . . . . . . . . . . . . . . . . . . . . . 436
Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Safety System Check . . . . . . . . . . . . . . . . . . . . . 60
Satellite Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Scheduling Appointments . . . . . . . . . . . . . . . . 433
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Extender . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
How to Wear Seat Belts Properly . . . . . . . 55
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . 57
Reminders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Replacing after a Crash . . . . . . . . . . . . . . . . . 60
Use During Pregnancy . . . . . . . . . . . . . . . . . . 59
Seats Adjustment, Front . . . . . . . . . . . . . . . . . . . . . . 46
Center Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . 45
Heated and Ventilated Front . . . . . . . . . . . . 52
Heated, Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Lumbar Adjustment, Front . . . . . . . . . . . . . . 48
Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Power Adjustment, Front . . . . . . . . . . . . . . . 47
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . 48 Seats (cont'd)
Underseat Storage . . . . . . . . . . . . . . . . . . . . . . 96
Securing Child Restraints . . . . . . . . . . . . . . 88, 92
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Vehicle Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 Accessories and Modifications . . . . . . . . . 323
Climate Control System . . . . . . . . . . . . . . . . 204
Doing Your Own Work . . . . . . . . . . . . . . . . . 323
Maintenance Records . . . . . . . . . . . . . . . . . . 422
Maintenance, General Information . . . . . 408
Parts Identification . . . . . . . . . . . . . . . . . . . . . 423
Scheduling Appointments . . . . . . . . . . . . . . 433
Service Electric Parking Brake Light . . . . . . . 118
Services Special Application . . . . . . . . . . . . . . . . . . . . . 415
Servicing System . . . . . . . . . . . . . . . . . . . . . . . . . 175
Servicing the Airbag . . . . . . . . . . . . . . . . . . . . . . 69
Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Shift Lock Control Function Check, Automatic Transmission . . . . . . . . . . . . . . . . 347
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Out of Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Side Blind Zone Alert (SBZA) . . . . . . . . . . . . . 280 Signals, Turn and Lane-Change . . . . . . . . . . . .143
Snow Plow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .318
Software Updates . . . . . . . . . . . . . . . . . . . . . . . . . 155
Special Application Services . . . . . . . . . . . . . . .415
Specifications and Capacities . . . . . . . . . . . . . 424
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110
Start Assist, Hill . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Start Vehicle, Remote . . . . . . . . . . . . . . . . . . . . . 20
Starter Switch Check . . . . . . . . . . . . . . . . . . . . . 347
Starting the Engine . . . . . . . . . . . . . . . . . . . . . . 232
Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .214
Heated Wheel . . . . . . . . . . . . . . . . . . . . . . . . . 100
Wheel Adjustment . . . . . . . . . . . . . . . . . . . . . 100
Wheel Controls . . . . . . . . . . . . . . . . . . . . . . . . 100
Steering Column Lock . . . . . . . . . . . . . . . . . . . . . .32
Steering Wheel Controls . . . . . . . . . . . . . . . . . . 151
Steps Power Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Stop/Start System . . . . . . . . . . . . . . . . . . . . . . . 233
Stoplamps and Back-up Lamps Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . 351
Storage Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Storage Areas Center Console . . . . . . . . . . . . . . . . . . . . . . . . . 96
Floor Console . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Glove Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Underseat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96