P203F
1 owner report and 30 manufacturer filings across 13 model years from Ram.
Where P203F shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2025 Ram 2500 | Unknown Or Other | 3 | — |
| 2021 Ram 2500 | Fuel System, Diesel | 3 | — |
| 2020 Ram 2500 | Fuel System, Diesel | 3 | — |
| 2019 Ram 2500 | Back Over Prevention | 3 | — |
| 2025 Ram 3500 | Unknown Or Other | 3 | — |
| 2021 Ram 3500 | Fuel System, Gasoline | 3 | — |
| 2020 Ram 3500 | Fuel System, Diesel | 3 | — |
| 2019 Ram 3500 | Back Over Prevention | 3 | — |
| 2026 Ram 2500 | Fuel/Propulsion System | 2 | — |
| 2026 Ram 3500 | Fuel/Propulsion System | 2 | — |
| 2022 Ram 2500 | Fuel System, Diesel | 1 | — |
| 2022 Ram 3500 | Fuel System, Diesel | 1 | — |
| 2018 Ram 3500 | Service Brakes | — | 1 |
A model year appears here because the code is named in its record, not because every one of these vehicles sets it. Counts are mentions in the federal files, not failure rates — nobody publishes the denominator.
What it gets filed under
What owners said
Source: NHTSA complaint databaseOwners’ own words, one per nameplate, scrubbed of anything identifying. These are unverified reports filed with NHTSA — they are what was said, not a finding that it was true.
ABS and Traction Control lights on, beeping, Check Engine Light On, Codes U1408-00, C0020-01, C0044-28, P203F
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names P203F. Quoting the document number at a service desk is often the fastest route to a diagnosis someone has already written down.
- S2525000002 REV. B2026-03-31 · Unknown Or Other
- Diesel Exhaust Fluid (DEF) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code (DTC) P203F – Reductant Level Too Low.
- S2525000002 REV. A2026-02-09 · Fuel/Propulsion System
- Diesel Exhaust Fluid (DEF) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code (DTC) P203F – Reductant Level Too Low.
- S25250000022025-05-16 · Unknown Or Other
- Diesel Exhaust Fluid (DEF) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code (DTC) P203F – Reductant Level Too Low.
- 18-034-21 REV. A2021-11-10 · Fuel System, Diesel
- P203E and P203F Additional Diagnostic Information This bulletin provides additional information regarding diagnosing Diesel Exhaust Fluid (DEF) issue in extreme cold weather. Diagnostic Trouble Codes (DTCs) P203E - Reductant Level Sensor 1 Circuit Intermittent and/or P203F - Reductant Level Too Low set.
- 18034212021-04-02 · Fuel System, Diesel
- P203E and P203F Additional Diagnostic Information This bulletin provides additional information regarding diagnosing Diesel Exhaust Fluid (DEF) issue in extreme cold weather. Diagnostic Trouble Codes (DTCs) P203E - Reductant Level Sensor 1 Circuit Intermittent and/or P203F - Reductant Level Too Low set.
- 18-034-212021-04-02 · Fuel System, Gasoline
- P203E and P203F Additional Diagnostic Information This bulletin provides additional information regarding diagnosing Diesel Exhaust Fluid (DEF) issue in extreme cold weather. Diagnostic Trouble Codes (DTCs) P203E - Reductant Level Sensor 1 Circuit Intermittent and/or P203F - Reductant Level Too Low set.
What P203F means
Source: SAE J2012 / OBD-IIP203F sits in the generic range of the OBD-II standard, so it means the same thing on every vehicle sold in the United States — but WhichTrim does not carry a definition for it and will not invent one. What is on this page is the record: who named it and on what.
A stored code names the test that failed, never the part that caused it. It is the starting point of a diagnosis, not its conclusion — the same code has several possible causes and the cheap one is not always right.
Common questions about P203F
Source: NHTSA files and the OBD-II standardCan I keep driving with P203F stored?
Nobody can answer that from the code alone, and a site that does is guessing. A steady light generally means the fault was logged and the vehicle is in a reduced-risk mode; a flashing light means stop soon, because a misfiring engine can destroy a catalytic converter in minutes. The safe read of this page is the mileage and the components, not permission.
Does a code mean the car is recalled?
No. Recalls are filed by campaign and matched by VIN, and none of them are triggered by a scan tool. If you want to know whether an open recall applies to one specific vehicle, check the VIN at nhtsa.gov/recalls — that is the only source that settles it.
Why do the counts here differ from other sites?
Because these are not estimates. Every number on this page is a count of documents in NHTSA's own files: manufacturer communications that name the code in their filed summary, and owner complaints that name it in the narrative. We do not model, weight or extrapolate them.
Will clearing the code fix it?
Clearing turns the light off and erases the freeze-frame data a technician would have used to work out what happened. If the condition is still there the code returns, usually within a few drive cycles, and the diagnosis now starts from less information than before.