P0403: 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 P0403 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

8 complaints filed with NHTSA mention P0403, 7 of them since 2015, across 5 different models. The component owners most often filed it under: fuel/propulsion system.

Most-reported models

VehicleComplaintsModel years reported
CHEVROLET VOLT42016, 2017

Manufacturer service bulletins that name P0403

21 technical service bulletins and manufacturer communications filed with NHTSA mention P0403, from 5 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • JEEP WRANGLER (2023), bulletin 10236946: Flash: Powertrain Control Module (PCM) Updates Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation, a technician may find one or more of the following Diagnostic Trouble C…
  • JEEP GLADIATOR (2023), bulletin 11004882: "Flash: Powertrain Control Module (PCM) Updates **Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): P…
  • RAM 1500 (2020, 2021, 2022), bulletin 10212342: Malfunction Indicator Lamp (MIL) Illumination. Diagnostic Trouble Code (DTC) P0403 ? EGR Control Circuit Open, Set.
  • CHEVROLET EQUINOX (2018, 2017), bulletin 10154653: This engineering information PI ends the need for information from the field for an MIL Lamp On, DTC P0403 Set.
  • GMC TERRAIN (2018), bulletin 10154653: This engineering information PI ends the need for information from the field for an MIL Lamp On, DTC P0403 Set.
  • FORD TRANSIT CONNECT (2014, 2015, 2016), bulletin 10094582: SOME 2014-2016 TRANSIT CONNECT VEHICLES EQUIPPED WITH THE 2.5L ENGINE MAY EXHIBIT A CONSTANT OR INTERMITTENT ILLUMINATED MIL WITH VARIOUS DRIVABILITY ISSUES AND ONE OR MORE OF THE FOLLOWING DTCS: P0010, P0103, P0104, P01…

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.