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 | Parts |
|---|---|---|---|---|
| 2025 Ram 2500 | Not specified | 3 | — | |
| 2021 Ram 2500 | Fuel/Propulsion System | 3 | — | Fuel pump → |
| 2020 Ram 2500 | Fuel/Propulsion System | 3 | — | Fuel pump → |
| 2019 Ram 2500 | Fuel/Propulsion System | 3 | — | Fuel pump → |
| 2025 Ram 3500 | Not specified | 3 | — | |
| 2021 Ram 3500 | Back Over Prevention | 3 | — | |
| 2020 Ram 3500 | Fuel/Propulsion System | 3 | — | Fuel pump → |
| 2019 Ram 3500 | Back Over Prevention | 3 | — | |
| 2026 Ram 2500 | Fuel/Propulsion System | 2 | — | Fuel pump → |
| 2026 Ram 3500 | Fuel/Propulsion System | 2 | — | Fuel pump → |
| 2022 Ram 2500 | Fuel/Propulsion System | 1 | — | Fuel pump → |
| 2022 Ram 3500 | Fuel/Propulsion System | 1 | — | Fuel pump → |
| 2018 Ram 3500 | Service Brakes | — | 1 | Brake pads → |
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.
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P203F by make
The same record, one make at a time: the model years, bulletins and owner reports that name P203F on that maker’s vehicles.
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
30 manufacturer filings name P203F. Start with what the maker wrote down.
A code names the test that failed, not the part. A bulletin that names it is often a diagnosis someone has already written down — quote its number at the service desk.
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names P203F.
- S2525000002 REV. B Service bulletin2026-03-31 · Unknown Or Other
- Diesel Exhaust Fluid (DEF) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code (DTC) P203F – Reductant Level Too Low.
- S2525000002 REV. A Service bulletin2026-02-09 · Fuel/Propulsion System
- Diesel Exhaust Fluid (DEF) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code (DTC) P203F – Reductant Level Too Low.
- S2525000002 Service bulletin2025-05-16 · 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. A Service bulletin2021-11-10 · 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.
- 1803421 Service bulletin2021-04-02 · 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.
- 18-034-21 Service bulletin2021-04-02 · 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.
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 means a fault was logged and the car should be checked soon; a flashing light means a severe misfire — slow down and get it seen as soon as possible, because severe misfire can quickly damage the catalytic converter. 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.