P04FB: 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 P04FB 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

5 complaints filed with NHTSA mention P04FB, 5 of them since 2015, across 2 different models. The component owners most often filed it under: engine.

Most-reported models

VehicleComplaintsModel years reported
CHEVROLET EQUINOX32025

Manufacturer service bulletins that name P04FB

21 technical service bulletins and manufacturer communications filed with NHTSA mention P04FB, from 5 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • BUICK ENVISION (2021, 2022, 2023, 2024), bulletin 10249959: This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
  • CADILLAC CT4 (2020, 2021, 2022, 2023), bulletin 10249959: This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
  • CHEVROLET BLAZER (2020, 2021, 2022, 2023), bulletin 10249959: This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
  • GMC ACADIA (2020, 2021, 2022, 2023), bulletin 10249959: This Preliminary information communicates the potential for condensation to freeze up inside the Crankcase Pressure Sensor causing dtc P04FB to set.
  • RAM PROMASTER (2015), bulletin 10148938: Flash: 3.0L Diagnostic And System Improvements This bulletin involves reprogramming the Engine Control Module (ECM) with the latest available software. A small number of customers may experience a Malfunction Indicator L…

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.