OnStar Over the Air Update for TTY / TDD Operation and Continuous Improvement Changes – 2019-2021 Buick Cadillac Chevrolet GMC

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Copyright 2020 General Motors LLC. All Rights Reserved.
Service Bulletin Bulletin No.: 20-NA-196
Date: November, 2020
TECHNICAL
Subject: OnStar Over the Air Update for TTY / TDD Operation and Continuous Improvement
Changes
Brand: Model:
Model Year: VIN:
Engine: Transmission:
from to from to
Buick
Enclave 2019 2020
— — — —
Encore GX
(VIN M) 2020
2021
Encore 2021
Cadillac
CT4 2020 2021
— — — —
CT5 2020 2021
CT6 2019 2021
XT4 2019 2021
XT5 2020 2021
XT6 2020 2021
Escalade 2021 2021
Chevrolet
Blazer 2019 2021
— — — —
Bolt EV 2020 2020
Camaro 2019 2021
Colorado 2019 2021
Corvette 2020 2020
Cruze 2019 2019
Equinox 2019 2021
Malibu 2019 2021
Onix 2020 2021
S10 2021 2021
Silverado
1500 (New
Model)
2019 2019
Silverado
1500 2020 2021
Silverado
2500HD/
3500HD
2020 2021
Spark 2019 2021
Suburban 2021 2021
Tahoe 2021 2021
Trailblazer
(VIN M) 2021 2021
Traverse 2019 2020
Trax 2019 2021
Page 2 November, 2020 Bulletin No.: 20-NA-196
Brand: Model:
Model Year: VIN:
Engine: Transmission:
from to from to
GMC
Acadia 2020 2020
— — — —
Canyon 2019 2021
Sierra 1500
(New Model) 2019 2019
Sierra 1500 2020 2021
Sierra
2500HD/
3500HD
2020 2021
Terrain 2019 2021
Yukon 2021 2021
Involved Region or Country North America, Middle East, Argentina, Brazil, Bolivia, Chile, Colombia, Ecuador, Peru,
Uruguay
Additional Options (RPOs) Equipped with OnStar® (UE1), or Mobile Internet Connectivity (VV4) and without
Deactivated Vehicle Communication System (UDA)
Condition
Some customers may inquire about continued OnStar functionality after the 3G network
is sunset. Some OnStar modules and services rely on the 3G network for functionality.
This includes some TTY/TDD functionalities in certain vehicles. The telecommunications
provider is scheduling to sunset the 3G network in February 2022. In addition to this, a
continuous improvement software update is being released with updates made on the
following areas: TTY/TDD, Turn by Turn (TBT), diagnostics, remote services, GPS time
and date, and other general system improvements.
Improvements will vary by system generation, model, and model year, but most notable
may include:
• Support 3G sunset requirements
• TTY/TDD – Teletype or Text Telephone functionality for speech-impaired, deaf, or hard
of hearing persons
• Failed remote commands – Stolen Vehicle Slowdown, Remote Ignition Block,
On-Demand Diagnostics
• Vehicle speed limit values is not stored after boot-up during remote ignition block
• Prevent possible incorrect data usage after future network carrier changes are
implemented
• Prevent possible loss of GPS if cellular carriers enable an MDT (Minimization of Drive
Tests – provides carriers information on signal strength and location) feature in their
network
• GPS time and date reports can cause false messages for Service Air Filter message,
incorrect clock time displayed, or Super Cruise disengagement
• Super Cruise is inconsistently toggling precise positioning mode. This can cause the
Super Cruise system to disengage when no visible issue exists
• False collision event call or loss of audio during OnStar call (2021 model year VIP
programs only)
• Radio stays awake due to TBT route download, or OTA package download failures
• TBT destination addresses missing in Recent or Favorites list
• DTC enhancements for OnStar to serial data gateway module or radio, clearing DTCs
and false loss of communication
• Loss of WiFi connection when system transitions from 2G network to 3G network
coverage
• Dealer service tool capability to clear Stolen Vehicle Slowdown
• Navigation pointer drifts on screen
• Invalid CAN data causes ECM to trigger false MIL (2020 model year VIP models only)
• Wrong icon displayed after a call is disconnected
• Location masking data is incorrectly updated
• Packet data retry timer expires during an emergency call retry
• Cellular Signal quality indicator is set incorrectly
• Feature precedence is not implemented for vehicle task manager versus OTA
• Invalid GPS data is reported for eCall/ERA variants (non-US markets only)
Bulletin No.: 20-NA-196 November, 2020 Page 3
• Modem reset during an Advisor call
• Vehicle charge interrupt data not stored properly
Cause
As the telecommunications industry evolves, the 3G network used by some OnStar
modules is being decommissioned, or sunset, to be replaced by newer technologies.
Other listed conditions may be caused by software anomalies.
Correction
This update can occur remotely through Over-the-Air (OTA) update to the OnStar module.
However, some customers may decline the vehicle update, or the update may be
unsuccessful. Along with the vehicles mentioned above, vehicles in unconnected
markets, and fleet customers may need the dealer to replace the OnStar module.
Service Procedure
Note: There is no scan tool data that identifies the
OnStar module version in these vehicles. Verify the
customer concern is not related to more common
causes prior to utilizing this service bulletin information.
1. Certain vehicle radio systems may show an
Update History in the radio menu. Before
proceeding with diagnostics or part replacements,
check the Update History for an OnStar update
installed on or after September 10, 2020. The
update version number could vary based on
OnStar generation, vehicle Year, Make, and Model.
1.1. If an OnStar update was installed on or after
September 10, 2020, then this bulletin does
not apply. Refer to SI for diagnostic
information related to the condition that is
occurring.
1.2. If there is no record of an OnStar update
installed on or after September 10, 2020, then
the over-the-air update may not have
occurred on this vehicle. Read the important
note then proceed to Step 2.
Important: At the release of this service bulletin, parts
are currently not available that are built with the latest
software update being delivered via OTA. If a module
must be replaced for a failed OnStar OTA message,
then the vehicle will have to be re-enrolled in the OTA
update process. This re-enrollment occurs
automatically. The customer may see additional
prompts to install the update package at a later date.
Please encourage that they follow the on-screen
prompts and accept the installation when convenient to
do so.
2. Does the radio indicate a failed OTA update and to
return to the dealer?
2.1. If no failed OTA message is displayed in the
radio, this bulletin may not apply. Do NOT
replace the OnStar module per this bulletin.
Replacement parts currently do not have the
fixes being delivered via OTA. Refer to
published diagnostics in SI.
2.2. If there is a failed OTA message displayed for
the OnStar module, then replace the OnStar
module. Refer to the appropriate
Communication Interface Module
Replacement document in SI.
Until such time as revised parts become available,
dealers should only replace the OnStar module if the
radio indicates this OnStar OTA failed, or when
published diagnostics indicate replacement is
necessary. This bulletin will be revised once parts
containing the fixes become available. That is currently
not expected to occur until approximately the second
quarter of 2021.
Warranty Information
For vehicles repaired under warranty, use:
Labor
Operation
Description Labor Time
9700019
Communication Interface
Module Replacement for
failed OTA update
N202298820
Use
Published
Labor
Operation
Time
Version 1
Modified Released October 27, 2020
GM bulletins are intended for use by professional technicians, NOT a “do-it-yourselfer”. They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
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