P238FWater in Fuel Condition - Sensor B
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P238F is no wiring fault: it states that water-in-fuel sensor B has detected water, meaning the separator at that point has collected enough to bridge the probe. Ram's 2022 heavy-duty pickups (2500 to 5500) are covered by Stellantis case S2214000004, which keeps it apart from the circuit code P238D: with P238F stored, the filter on the frame has to be emptied completely and the fuel tested for water before any electrical diagnosis. For sensor A the equivalent is P2269, which Ram's 2025–26 Cummins trucks report with the MIL. Water in diesel fuel damages high-pressure pumps and injectors and promotes microbial growth, so drain promptly, find the source (tank, fuel station, condensation) and replace the filter if needed.
- What you may notice
- Water-in-fuel lamp or message on
- Rough running or power loss if water reaches the injection system
- MIL on some vehicles
- Likely causes
- LikelyWater collected in the chassis filter separator
- PossibleFuel contaminated with water from tank or filling station
- PossibleSeparator drained incompletely after an earlier warning
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €0 – €200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.