P2128: 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 P2128 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 P2128, 7 of them since 2015, across 8 different models. The component owners most often filed it under: electrical system.

Manufacturer service bulletins that name P2128

13 technical service bulletins and manufacturer communications filed with NHTSA mention P2128, from 5 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • FORD F-600 SD (2023, 2024), bulletin 10253556: Some 2023-2024 F-Super Duty vehicles may exhibit an illuminated powertrain malfunction (wrench) indicator with diagnostic trouble codes (DTC) P2122, P2123, P2127, P2128, and/or P2138 stored in the powertrain control modu…
  • FORD F-150 (2021, 2022, 2023, 2024), bulletin 11008946: Some 2021-2024 F-150 non-Lightning vehicles may exhibit an illuminated powertrain malfunction (wrench) indicator with diagnostic trouble codes (DTCs) P2122, P2123, P2127, P2128, and/or P2138 stored in the powertrain cont…
  • FORD F-250 SD (2017), bulletin 10125085: Some 2017 F-Super Duty vehicles built on or before 28-Aug-2017, may exhibit an intermittent loss of throttle pedal response, illuminated wrench, hill descent, airbag, anti-lock brake system (ABS) and/or advanced trac war…
  • CADILLAC ESCALADE (2016), bulletin 10114935: This Preliminary Information communication provides information to the technician about vehicles that may have Service Engine Soon Malfunction Indicator Lamp on or reduced power message. Technician may find Diagnostic Tr…
  • CHEVROLET SILVERADO 2500 (2016), bulletin 10114935: This Preliminary Information communication provides information to the technician about vehicles that may have Service Engine Soon Malfunction Indicator Lamp on or reduced power message. Technician may find Diagnostic Tr…
  • GMC SIERRA 2500 (2016), bulletin 10114935: This Preliminary Information communication provides information to the technician about vehicles that may have Service Engine Soon Malfunction Indicator Lamp on or reduced power message. Technician may find Diagnostic Tr…

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.