P0402: owner reports and bulletins

Powertrain (generic, all makes). We haven't written the explanation for this code yet. Below is what owners and manufacturers have filed with NHTSA.

Got P0402 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

11 complaints filed with NHTSA mention P0402, 8 of them since 2015, across 10 different models. The component owners most often filed it under: engine.

Manufacturer service bulletins that name P0402

60 technical service bulletins and manufacturer communications filed with NHTSA mention P0402, from 11 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • GMC SIERRA 2500 (2024), bulletin 10235660: This technical bulletin provides a procedure to correct the condition of Malfunction Indicator Lamp Illuminated with DTC P0402 Set.
  • CHEVROLET SILVERADO 2500 (2024), bulletin 10235660: This technical bulletin provides a procedure to correct the condition of Malfunction Indicator Lamp Illuminated with DTC P0402 Set.
  • CHEVROLET SILVERADO 3500 (2024), bulletin 10237942: This technical bulletin provides a procedure to correct the condition of Malfunction Indicator Lamp Illuminated with DTC P0402 Set.
  • GMC SIERRA 3500 (2024), bulletin 10247528: This service bulletin provides a procedure to correct the condition of Malfunction Indicator Lamp Illuminated with DTCs P0402, P062D, P144E, P242B, P2459, and/or P2635Set.
  • LINCOLN CORSAIR (2023), bulletin 10249759: This article supersedes TSB 23-2275 to add Step 3 to the Service Procedure, add P0402 and remove the production fix date. Some 2023 Escape/Corsair vehicles equipped with a 2.0L EcoBoost engine may exhibit an illuminated …
  • FORD ESCAPE (2023), bulletin 10249759: This article supersedes TSB 23-2275 to add Step 3 to the Service Procedure, add P0402 and remove the production fix date. Some 2023 Escape/Corsair vehicles equipped with a 2.0L EcoBoost engine may exhibit an illuminated …

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.