P20B9: owner reports and bulletins
Got P20B9 on your scanner? Tell the mechanic your year, make, model and any symptoms and you'll get the likely cause and what to check first. Ask about this code.
What owners report to NHTSA
9 complaints filed with NHTSA mention P20B9, 9 of them since 2015, across 3 different models. The component owners most often filed it under: engine.
Most-reported models
| Vehicle | Complaints | Model years reported |
|---|---|---|
| CHEVROLET SILVERADO 2500 | 4 | 2011, 2013, 2017, 2020 |
| CHEVROLET SILVERADO 1500 | 3 | 2020, 2021 |
Manufacturer service bulletins that name P20B9
4 technical service bulletins and manufacturer communications filed with NHTSA mention P20B9, from 2 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- FORD F-150 (2018, 2019, 2020, 2021), bulletin 10212102: Some 2018-2021 F-150 vehicles equipped with a 3.0L diesel engine, 2016-2022 F-650/F-750 vehicles equipped with a 6.7L engine, and 2017-2022 F-Super Duty vehicles equipped with a 6.7L engine and built on or before 08-Mar-…
- FORD F-750 SD (2016, 2017, 2018, 2019), bulletin 10201907: Some 2018-2020 F-150 vehicles built on or before 1-Apr-2020 equipped with a 3.0L diesel engine, 2017-2019 F-Super Duty vehicles built on or before 30-Oct-2019 equipped with a 6.7L engine and 2016-2019 F-650/F-750 vehicle…
- HINO HINO, bulletin 10141617: SB-18-013 COE HEATED DEF LINE DTC'S P20BD, P20B9, OR P20C1
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.