Chevrolet Silverado 1500 2018–2021 — technical service bulletin
Bulletin 20NA203 · NHTSA communication 10187761 · issued Jan 5, 2021
Technical service bulletin
communication type
Equipment Adaptive/mobility
component
2018–2021
model years
20
vehicle entries
Official summary
This informational bulletin explains how the regen works for the DEF system and how it works at different levels.
Vehicles covered
- 2018 Chevrolet Silverado 1500
- 2021 Chevrolet Silverado 1500
- 2018 Chevrolet Silverado 2500
- 2019 Chevrolet Silverado 2500
- 2020 Chevrolet Silverado 2500
- 2021 Chevrolet Silverado 2500
- 2019 Chevrolet Silverado 3500
- 2020 Chevrolet Silverado 3500
- 2021 Chevrolet Silverado 3500
- 2019 Chevrolet Silverado 4500
- 2021 GMC Sierra 1500
- 2018 GMC Sierra 2500
- 2019 GMC Sierra 2500
- 2020 GMC Sierra 2500
- 2021 GMC Sierra 2500
- 2019 GMC Sierra 3500
- 2020 GMC Sierra 3500
- 2021 GMC Sierra 3500
- 2018 GMC Sierra Denali
- 2019 GMC Sierra Denali
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.