2020 GMC SIERRA ECU

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
OnStar 477
OnStar
OnStar Overview
OnStar Overview . . . . . . . . . . . . . 477
OnStar Services
Emergency . . . . . . . . . . . . . . . . . . . 478
Security . . . . . . . . . . . . . . . . . . . . . . 479
OnStar Additional Information
OnStar AdditionalInformation . . . . . . . . . . . . . . . . . . 479
OnStar Overview
=Voice Command Button
QBlue OnStar Button
>Red Emergency Button
This vehicle may be equipped with a
comprehensive, in-vehicle system
that can connect to an OnStar
Advisor for Emergency, Security,
Navigation, Connections, and
Diagnostics Services. OnStar
services may require a paid service
plan and data plan. OnStar requires
the vehicle battery and electrical
system, cellular service, and GPS
satellite signals to be available and
operating. OnStar acts as a link to
existing emergency service
providers. OnStar may collect
information about you and your
vehicle, including location
information. See OnStar User Terms, Privacy Statement, and
Software Terms for more details
including system limitations at
www.onstar.com (U.S.) or
www.onstar.ca (Canada).
The OnStar system status light is
next to the OnStar buttons. If the
status light is:
.
Solid Green: System is ready.
. Flashing Green: On a call.
. Red: Indicates a problem.
. Off: System is off. Press
Q
twice to speak with an OnStar
Advisor.
Press
Qor call 1-888-4ONSTAR
(1-888-466-7827) to speak to an
Advisor.
Functionality of the Voice Command
button may vary by vehicle and
region.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
478 OnStar
Press=to:
. Open the OnStar app on the
infotainment display. See the
infotainment manual for
information on how to use the
OnStar app.
Or
. Give OnStar Turn-by-Turn
Navigation voice commands.
. Obtain and customize the Wi-Fi
hotspot name or SSID and
password, if equipped.
Press
Qto connect to an
Advisor to:
. Verify account information or
update contact information.
. Get driving directions.
. Receive a Diagnostic check of
the vehicle's key operating
systems.
. Receive Roadside Assistance.
. Manage Wi-Fi Settings,
if equipped. Press
>to get a priority connection
to an OnStar Advisor available 24/
7 to:
. Get help for an emergency.
. Be a Good Samaritan or
respond to an AMBER Alert.
. Get assistance in severe
weather or other crisis situations
and find evacuation routes.OnStar Services
Emergency
Emergency Services require an
active safety and security plan. With
Automatic Crash Response, built-in
sensors can automatically alert a
specially trained OnStar Advisor
who is immediately connected in to
the vehicle to help.
Press
>for a priority connection to
an OnStar Advisor who can contact
emergency service providers, direct
them to your exact location, and
relay important information.
With OnStar Crisis Assist, specially
trained Advisors are available
24 hours a day, 7 days a week, to
provide a central point of contact,
assistance, and information during a
crisis.
With Roadside Assistance, Advisors
can locate a nearby service provider
to help with a flat tire, a battery
jump, or an empty gas tank.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
OnStar 479
Security
If equipped, OnStar provides these
services:
.With Stolen Vehicle Assistance,
OnStar Advisors can use GPS to
pinpoint the vehicle and help
authorities quickly recover it.
. With Remote Ignition Block,
if equipped, OnStar can block
the engine from being restarted.
. With Stolen Vehicle Slowdown,
if equipped, OnStar can work
with law enforcement to
gradually slow the vehicle down.
Theft Alarm Notification
If equipped, if the doors are locked
and the vehicle alarm sounds, a
notification by text, e-mail, or phone
call will be sent. If the vehicle is
stolen, an OnStar Advisor can work
with authorities to recover the
vehicle.
OnStar Additional
Information
In-Vehicle Audio Messages
Audio messages may play important
information at the following times:
.Prior to vehicle purchase. Press
Qto set up an account.
. After change in ownership and
at 90 days.
Transferring Service
PressQto request account transfer
eligibility information. The Advisor
can cancel or change account
information.
Selling/Transferring the
Vehicle
Call 1-888-4ONSTAR
(1-888-466-7827) immediately to
terminate your OnStar or connected
services if the vehicle is disposed
of, sold, transferred, or if the
lease ends.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
482 OnStar
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, identify whether
updates or changes are available,
or deliver updates or changes. An
active OnStar agreement constitutes
consent to these software updates
or changes and agreement that
either OnStar or GM may remotely
deliver them to the vehicle.Privacy
The complete OnStar Privacy
Statement may be found at
www.onstar.com (U.S.),
or www.onstar.ca (Canada). We
recommend that you review it. If you
have any questions, call
1-888-4ONSTAR (1-888-466-7827)
or press
Qto speak with an
Advisor. Users of wireless
communications are cautioned that
the privacy of any information sent
via wireless cellular communications
cannot be assured. Third parties
may unlawfully intercept or access
transmissions and private
communications without consent.
OnStar - Software
Acknowledgements
Certain OnStar components include
libcurl and unzip software and other
third party software. Below are the
notices and licenses associated with
libcurl and unzip and for other third
party software please see http://
opensource.lge.com/index
www.onstar.com/us/en/ libcurl:
COPYRIGHT AND PERMISSION
NOTICE
Copyright (c) 1996 - 2010, Daniel
Stenberg, .
All rights reserved.
Permission to use, copy, modify,
and distribute this software for any
purpose with or without fee is
hereby granted, provided that the
above copyright notice and this
permission notice appear in all
copies.
THE SOFTWARE IS PROVIDED
“AS IS,”
WITHOUT WARRANTY OF
ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT
LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE
AND NONINFRINGEMENT OF
THIRD PARTY RIGHTS. IN NO
EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF
CONTRACT, TORT OR

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
OnStar 483
OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE
USE OR OTHER DEALINGS IN
THE SOFTWARE.
Except as contained in this notice,
the name of a copyright holder shall
not be used in advertising or
otherwise to promote the sale, use
or other dealings in this Software
without prior written authorization of
the copyright holder.
unzip:
This is version 2005-Feb-10 of the
Info-ZIP copyright and license. The
definitive version of this document
should be available at ftp://
ftp.info-zip.org/pub/infozip/
license.html indefinitely.
Copyright (c) 1990-2005 Info-ZIP. All
rights reserved.
For the purposes of this copyright
and license,“Info-ZIP”is defined as
the following set of individuals:
Mark Adler, John Bush, Karl Davis,
Harald Denker, Jean-Michel Dubois,
Jean-loup Gailly, Hunter Goatley, Ed Gordon, Ian Gorman, Chris
Herborth, Dirk Haase, Greg Hartwig,
Robert Heath, Jonathan Hudson,
Paul Kienitz, David Kirschbaum,
Johnny Lee, Onno van der Linden,
Igor Mandrichenko, Steve P. Miller,
Sergio Monesi, Keith Owens,
George Petrov, Greg Roelofs, Kai
Uwe Rommel, Steve Salisbury,
Dave Smith, Steven M. Schweda,
Christian Spieler, Cosmin Truta,
Antoine Verheijen, Paul von Behren,
Rich Wales, Mike White.
This software is provided
“as is,”
without warranty of any kind,
express or implied. In no event shall
Info-ZIP or its contributors be held
liable for any direct, indirect,
incidental, special or consequential
damages arising out of the use of or
inability to use this software.
Permission is granted to anyone to
use this software for any purpose,
including commercial applications,
and to alter it and redistribute it
freely, subject to the following
restrictions: 1. Redistributions of source code
must retain the above copyright
notice, definition, disclaimer,
and this list of conditions.
2. Redistributions in binary form (compiled executables) must
reproduce the above copyright
notice, definition, disclaimer,
and this list of conditions in
documentation and/or other
materials provided with the
distribution. The sole exception
to this condition is redistribution
of a standard UnZipSFX binary
(including SFXWiz) as part of a
self-extracting archive; that is
permitted without inclusion of
this license, as long as the
normal SFX banner has not
been removed from the binary
or disabled.
3. Altered versions–including, but not limited to, ports to new
operating systems, existing
ports with new graphical
interfaces, and dynamic,
shared, or static library
versions–must be plainly
marked as such and must not

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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486 Connected Services
2. Say“Repeat.” System
responds with the last direction
given, then responds with
“OnStar ready,” then a tone.
Get My Destination
1. Press
=. System responds:
“OnStar ready,” then a tone.
2. Say “Get my destination.”
System responds with the
address and distance to the
destination, then responds with
“OnStar ready,” then a tone.
Send Destination to Vehicle
Directions can be sent to the
vehicle’s navigation screen,
if equipped.
Press
Q, then ask the Advisor to
download directions to the vehicle’s
navigation system, if equipped. After
the call ends, the navigation screen
will provide prompts to begin driving
directions. Routes that are sent to
the navigation screen can only be
canceled through the navigation
system. See www.onstar.com (U.S.) or
www.onstar.ca (Canada).
Connections
The following services help with
staying connected.
For coverage maps, see
www.onstar.com (U.S.) or
www.onstar.ca (Canada).
Ensuring Security
.
Change the default passwords
for the Wi-Fi hotspot and
myGMC mobile application.
Make these passwords different
from each other and use a
combination of letters, numbers,
and symbols to increase the
security.
. Change the default name of the
SSID (Service Set Identifier).
This is your network’s name that
is visible to other wireless
devices. Choose a unique name
and avoid family names or
vehicle descriptions. Wi-Fi Hotspot (If Equipped)
The vehicle may have a built-in
Wi-Fi hotspot that provides access
to the Internet and web content at
4G LTE speed. Up to seven mobile
devices can be connected. A data
plan is required. Use the in-vehicle
controls only when it is safe to
do so.
1. To retrieve Wi-Fi hotspot information, press
=to open
the OnStar app on the
infotainment display, then
select Wi-Fi Hotspot. On some
vehicles, touch Wi-Fi or Wi-Fi
Settings on the screen.
2. The Wi-Fi settings will display the Wi-Fi hotspot name (SSID),
password, and on some
vehicles, the connection type
(no Internet connection, 3G,
4G, 4G LTE), and signal quality
(poor, good, excellent).
3. To change the SSID or password, press
Qor call
1-888-4ONSTAR to connect
with an Advisor. On some

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
488 Index
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . . . 329
Accessory Power . . . . . . . . . . . . . . . 217
Active Fuel Management . . . . . . . 219
Adaptive Cruise Control . . . . . . . . 245
Add-On Electrical Equipment . . . 322
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . . 323
Additional Information
OnStar . . . . . . . . . . . . . . . . . . . . . . . 479
Additional Maintenance and Care . . . . . . . . . . . . . . . . . . . . . . 450
Adjustments
Lumbar, Front Seats . . . . . . . . . . . . 57
Air Cleaner/Filter, Engine . . . . . . . 344
Air Conditioning . . . . . . . . . . . 177, 179
Air Filter Life System . . . . . . . . . . . . . . . . . . . 343
Air Filter, Passenger Compartment . . . . . . . . . . . . . . . . . 183
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 182
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . 84
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . . . 77
Passenger Sensing System . . . . 78 Airbag System (cont'd)
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 76
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . . 77
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 76
Where Are the Airbags? . . . . . . . . 74
Airbags
Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . . . 83
Passenger Status Indicator . . . 137
Readiness Light . . . . . . . . . . . . . . 136
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . . . 83
System Check . . . . . . . . . . . . . . . . . . 72
Alarm Vehicle Security . . . . . . . . . . . . . . . . 37
Alert Lane Change . . . . . . . . . . . . . . . . . 274
Side Blind Zone (SBZA) . . . . . . 274
All-Season Tires . . . . . . . . . . . . . . . . 379
All-Terrain Tires . . . . . . . . . . . . . . . . . 381
Antilock Brake System (ABS) . . . 232 Warning Light . . . . . . . . . . . . . . . . . 141
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . 429
Interior . . . . . . . . . . . . . . . . . . . . . . . . 435

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490 Index
Caution, Danger, and Warning . . . . 3
Center Console Storage . . . . . . . . 114
Center High-MountedStoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . . . 369
Center Seat . . . . . . . . . . . . . . . . . . . . . 56
Chains, Tire . . . . . . . . . . . . . . . . . . . . 404
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . 124
Charging System Light . . . . . . . . . 138
Check Engine Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . 138
Ignition Transmission Lock . . . 363
Child Restraints Infants and Young Children . . . . . 87
Lower Anchors and Tethers
for Children . . . . . . . . . . . . . . . . . . . 92
Older Children . . . . . . . . . . . . . . . . . . 85
Securing . . . . . . . . . . . . 105, 108, 109
Systems . . . . . . . . . . . . . . . . . . . . . . . . 89
Circuit Breakers . . . . . . . . . . . . . . . . 370
Cleaning Exterior Care . . . . . . . . . . . . . . . . . 429
Interior Care . . . . . . . . . . . . . . . . . . 435
Climate Control Systems . . . . . . . 177 Air Conditioning . . . . . . . . . . . . . . 177
Dual Automatic . . . . . . . . . . . . . . . 179 Climate Control Systems (cont'd)
Heating . . . . . . . . . . . . . . . . . . . . . . . 177
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Cluster, Instrument . . . . . . . . . . . . . 127
Collision Damage Repair . . . . . . . 470
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . .113
Compass . . . . . . . . . . . . . . . . . . . . . . . 121
Connected Services Connections . . . . . . . . . . . . . . . . . . 486
Diagnostics . . . . . . . . . . . . . . . . . . . 487
Navigation . . . . . . . . . . . . . . . . . . . . 485
Connections Connected Services . . . . . . . . . . 486
Control Hill Descent . . . . . . . . . . . . . . . . . . 237
Traction and ElectronicStability . . . . . . . . . . . . . . . . . . . . . 235
Control Light Hill Descent . . . . . . . . . . . . . . . . . . 142
Control of a Vehicle . . . . . . . . . . . . . 188
Convex Mirrors . . . . . . . . . . . . . . . . . . 40
Coolant Engine Temperature Gauge . . 134
Engine TemperatureWarning Light . . . . . . . . . . . . . . . 145
Cooling . . . . . . . . . . . . . . . . . . . . 177, 179
Cooling System . . . . . . . . . . . . . . . . . 346 Courtesy Transportation
Program . . . . . . . . . . . . . . . . . . . . . . . 469
Cruise Control . . . . . . . . . . . . . . . . . . 243 Light . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Cruise Control, Adaptive . . . . . . . . 245
Cupholders . . . . . . . . . . . . . . . . . . . . . 113
Customer Assistance . . . . . . . . . . . 466 Offices . . . . . . . . . . . . . . . . . . . . . . . . 465
Text Telephone (TTY)Users . . . . . . . . . . . . . . . . . . . . . . . 466
Customer Information
Publications OrderingInformation . . . . . . . . . . . . . . . . . . 472
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . . 463
Cybersecurity . . . . . . . . . . . . . . . . . . . 475
D
Damage Repair, Collision . . . . . . . 470
Danger, Warning, and Caution . . . . 3
Data Collection
Infotainment System . . . . . . . . . . 476
OnStar . . . . . . . . . . . . . . . . . . . . . . . 476
Data Recorders, Event . . . . . . . . . 475
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 168
Defensive Driving . . . . . . . . . . . . . . . 187
Delayed Locking . . . . . . . . . . . . . . . . . 26