General Motors has issued a Technical Service Bulletin for a wide selection of 2019/2020/2021 model year vehicles that are experiencing a no-start or long crank condition. This includes the Chevy Silverado, GMC Sierra, Tahoe, Suburban, Yukon, and more.
Technical Service Bulletin: #20-NA-218
TSB #20-NA-218 Applies To:
- 2020 Cadillac CT5
- 2021 Cadillac Escalade & Escalade ESV
- 2020 Chevrolet Corvette
- 2019-2020 Chevrolet Silverado 1500
- 2020 Chevrolet Silverado HD
- 2021 Chevrolet Tahoe & Suburban
- 2019-2020 GMC Sierra 1500
- 2020 GMC Sierra HD
- 2021 GMC Yukon & Yukon XL
TSB #20-NA-218 Reported Conditions
Owners of the above affected vehicle models may experience a no-start or unusually long crank condition during start. Technicians may also find that DTC (trouble code) P12A6 may also be set after this occurs.
TSB #20-NA-218 – Cause & Fix
General Motors Engineers have determined that a software bug/anomaly in the engine control module (ECM) is responsible for these potential issues.
Owners who experience a no-start or long crank condition can contact their dealership for a software update that includes reprograming the ECM.