P1128: owner reports and bulletins

Powertrain (manufacturer-specific). We haven't written the explanation for this code yet. Below is what owners and manufacturers have filed with NHTSA.

Got P1128 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

3 complaints filed with NHTSA mention P1128, 1 of them since 2015, across 3 different models. The component owners most often filed it under: engine and engine cooling:engine.

Manufacturer service bulletins that name P1128

19 technical service bulletins and manufacturer communications filed with NHTSA mention P1128, from 2 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • DODGE DART (2014, 2015, 2016), bulletin 10148673: Flash: 1.4L Drivability Improvements This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software. A small number of customers may experience one or more of the follo…
  • FIAT 500E (2014, 2015), bulletin 10121933: Flash: 1.4L Diagnostic And System Improvements This bulletin involves reprogramming the Powertrain Control Module (PCM) with the latest software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. …
  • FIAT 500 (2014, 2015), bulletin 10151738: Flash: 1.4L Diagnostic And System Improvements This bulletin involves reprogramming the Powertrain Control Module (PCM) with the latest software. The customers may experience a Malfunction Indicator Lamp (MIL) illuminati…
  • FIAT 500L (2014), bulletin 10160023: Flash: 1.4L Powertrain Diagnostic And System Improvements This bulletin involves reprogramming the Powertrain Control Module (PCM) with the latest available software. A small number of customers may experience a Malfunct…

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.