General Motors has pushed out a substantial over the air update of the OnStar module for a long list of current and recent model year cars and trucks. Here’s how to check if you’ve gotten the update, what it fixes and what you can do if the update failed.

Technical Service Bulletin: #20-NA-196
Release Date: 10/27/2020

Vehicles TSB #20-NA-196 Applies To

  • 2019-2020 Buick Enclave
  • 2020-2021 Buick Encore and Encore GX
  • 2021 Cadillac CT4, CT5, CT6, XT4, XT5, XT6 & Escalade
  • 2019-2021 Chevy Blazer
  • 2020 Bolt EV
  • 2019-2021 Chevrolet Camaro
  • 2019-2021 Chevy Colorado / GMC Canyon
  • 2020 Chevrolet Corvette
  • 2019 Chevy Cruze
  • 2019-2021 Chevy Equinox / GMC Terrain
  • 2019-2021 Chevy Malibu
  • 2019-2021 Chevy Silverado / GMC Sierra
  • 2020-2021 Chevy Silverado HD / GMC Sierra HD
  • 2019-2021 Chevy Spark
  • 2021 Chevy Tahoe/Suburban, GMC Yukon/Yukon Denali
  • 2021 Chevy TrailBlazer (VIN M)
  • 2019-2020 Chevy Traverse / GMC Acadia
  • 2019-2021 Chevy Trax

TSB #20-NA-196 Fixes The Following Conditions

  • 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)
  • Modem reset during an Advisor call
  • Vehicle charge interrupt data not stored properly

How To Check If The Update Was Applied To Your Vehicle

Unfortunately, this is not easy. Some of the listed vehicles above have a menu inside the radio or infotainment system that lists the software update history. Look for an OnStar Update or Software Update on or about September 10th, 2020.The update version will vary based on year, make, and model.

Our 2019 Silverado’s update screen did not list OnStar Updates or any September 2020 update as of November 3rd, 2020.

What To Do If The Update Failed Or Has Not Yet Been Updated

Try to apply the update again if given the option. If that does not work or the update is listed as “failed” you will need to visit your dealership. If no failed update message is listed it is possible this TSB does not apply to you. If no update is found this may indicate this TSB does not apply to you.

OnStar Modules that have not updated correctly will need to be replaced. Unfortunately, parts for this replacement are not currently available and may take until the Spring 2021 to be in stock.