# P203F on the 2025 Ram 2500

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

Nobody has written a description of this code yet.

## Bulletins for this model year that name P203F

- [11031678](https://open.wenmarpro.com/bulletins/11031678), 2026-04-29: 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 \(DTCs\): ● \*\*P0088\-00 \- Fuel Rail Pressure Too High \- Bank 1.\*\* ● P20CF\-00 \- Exhaust After treatment Fuel Injector "A" Stuck Open. ● P20DB\-00 \- Exhaust After treatment Fuel Supply Control Stuck Open. ● U0109\-00 \- Lost Communication With Fuel Pump Control Module. ● P1451\-00 \- Diesel Particulate Filter System Performance. ● P2463\-00 \- Diesel Particulate Filter Restriction \- Soot Accumulation Bank 1. ● P2459\-00 \- Diesel Particulate Filter Regeneration Too Frequent. ● P0087\-00 \- Fuel Rail Pressure Too Low. ● P2540\-00 \- Low Pressure Fuel System Sensor Circuit Range/performance. ● P2543\-00 \- Low Pressure Fuel System Sensor Circuit Intermittent. ● P214D\-00 \- SCR NOX Catalyst Outlet Temperature Too High During Particulate Filter Regeneration. ● P242B\-00 \- Exhaust Gas Temperature Sensor Circuit Performance \- Bank 1 Sensor 3. ● P24DA\-00 \- Particulate Matter Sensor Exhaust Sample Error Bank 1. ● P20EE\-00 \- SCR Nox Catalyst Efficiency Below Threshold \- Bank 1 Catalyst 1. ● P226C\-00 \- Turbocharger Boost Control "A" Slow Response. ● P2281\-00 \- Air Leak Between MAF And Throttle Body. ● P229F\-00 \- NOX Sensor Circuit Range/performance \- Bank 1. ● P0100\-00 \- Mass Or Volume Air Flow Sensor "A" Circuit. ● P203F\-00 \- Reductant Level Too Low. ● P0423\-00 \- Heated Catalyst Efficiency Below Threshold Bank 1. ● P0263\-00 \- Cylinder 1 Contribution\-Balance. ● P0266\-00 \- Cylinder 2 Contribution\-Balance. ● P0269\-00 \- Cylinder 3 Contribution\-Balance. ● P0272\-00 \- Cylinder 4 Contribution\-Balance. ● P0275\-00 \- Cylinder 5 Contribution\-Balance. ● P0278\-00 \- Cylinder 6 Contribution/Balance. ● P026B\-00 \- Injection Timing Performance. ● P020A\-00 \- Cylinder 1 Injection Timing. ● P020B\-00 \- Cylinder 2 Injection Timing. ● P020C\-00 \- Cylinder 3 Injection Timing. ● P020D\-00 \- Cylinder 4 Injection Timing. ● P020E\-00 \- Cylinder 5 Injection Timing. ● P020F\-00 \- Cylinder 6 Injection Timing. ● P06B9\-00 \- Cylinder 1 Glow Plug Circuit Performance. ● P06BA\-00 \- Cylinder 2 Glow Plug Circuit Performance. ● P06BB\-00 \- Cylinder 3 Glow Plug Circuit Performance. ● P06BC\-00 \- Cylinder 4 Glow Plug Circuit Performance. ● P06BD\-00 \- Cylinder 5 Glow Plug Circuit Performance. ● P06BE\-00 \- Cylinder 6 Glow Plug Circuit Performance. Customers may also comment on one or more of the following: ● Long engine crank times, particularly after fuel filter change. ● Inverter drops out when shifting from P to D gears. ● Diesel Exhaust Fluid \(DEF\) level gauge slow to update after a refill. ● Poor cold start performance. ● Cruise control drops out/cancels on its own. ● Engine stumble, runs rough, or a slight lack of power. The following software enhancements are also available: ● Reduce the occurrence of false faults Diagnostic Trouble Codes \(DTCs\) P0300\-00, \*\*P0088\-00\*\* and P0315\-00. ● Improved troubleshooting and repair accuracy for air handling components through APT test in wiTECH. ● DTC P1451\-00 re\-tune to reduce false faults. ● Improvements to allow DTC P2509\-00 faults to be cleared with wiTECH. ● Adaptive Cruise Control \(ACC\) software fix to prevent cruise control dropouts. ● Engine stumble fix for improved drivability. ● Engine stall detection allowing DTC P032F\-00 to clear after a power cycle. ● Allow multiple PROXI rewrites. ● Enable cold re\-prime \(DTC P208B\-00 improvement\) This bulletin involves inspecting and possibly reprogramming the Engine Control Module \(ECM/PCM\) with the latest available software
- [11031236](https://open.wenmarpro.com/bulletins/11031236), 2026-04-10: Diesel Exhaust Fluid \(DEF\) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code \(DTC\) P203F – Reductant Level Too Low.
- [11028891](https://open.wenmarpro.com/bulletins/11028891), 2026-02-19: Diesel Exhaust Fluid \(DEF\) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code \(DTC\) P203F – Reductant Level Too Low.
- [11028764](https://open.wenmarpro.com/bulletins/11028764), 2026-02-12: Flash: Powertrain Control Module \(PCM\) Updates Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes \(DTCs\): ● \*\*P20CF \- 00 Exhaust After treatment Fuel Injector "A" Stuck Open. ● P20DB \- 00 Exhaust After treatment Fuel Supply Control Stuck Open. ● U0109 \- 00 Lost Communication With Fuel Pump Control Module. ● P1451 \- 00 Diesel Particulate Filter System Performance. ● P2463 \- 00 Diesel Particulate Filter Restriction \- Soot Accumulation Bank 1. ● P2459 \- 00 Diesel Particulate Filter Regeneration Too Frequent.\*\* ● P0263 \- 00 Cylinder 1 Contribution/balance. ● P0266 \- 00 Cylinder 2 Contribution\-balance. ● P0269 \- 00 Cylinder 3 Contribution/balance. ● P0272 \- 00 Cylinder 4 Contribution/balance. ● P0275 \- 00 Cylinder 5 Contribution/balance. ● P0278 \- 00 Cylinder 6 Contribution/balance. ● P026B \- 00 Injection Timing Performance. ● P020A \- 00 Cylinder 1 Injection Timing. ● P020B \- 00 Cylinder 2 Injection Timing. ● P020C \- 00 Cylinder 3 Injection Timing. ● P020D \- 00 Cylinder 4 Injection Timing. ● P020E \- 00 Cylinder 5 Injection Timing. ● P020F \- 00 Cylinder 6 Injection Timing. ● P06B9 \- 00 Cylinder 1 Glow Plug Circuit Performance. ● P06BA \- 00 Cylinder 2 Glow Plug Circuit Performance. ● P06BB \- 00 Cylinder 3 Glow Plug Circuit Performance. ● P06BC \- 00 Cylinder 4 Glow Plug Circuit Performance. ● P06BD \- 00 Cylinder 5 Glow Plug Circuit Performance. ● P06BE \- 00 Cylinder 6 Glow Plug Circuit Performance. ● P0072 \- 00 Ambient Air Temperature Sensor Circuit "A" Low. ● P0087 \- 00 Fuel Rail Pressure Too Low. ● P2540 \- 00 Low Pressure Fuel System Sensor Circuit Range/Performance. ● P2543 \- 00 Low Pressure Fuel System Sensor Circuit Intermittent. ● P0100 \- 00 Mass Or Volume Air Flow Sensor "A" Circuit. B18 FSAR\-TSB\-6871 \-2\- ● P203F \- 00 Reductant Level Too Low. ● P0423 \- 00 Heated Catalyst Efficiency Below Threshold Bank 1. ● P20EE \- 00 SCR NOX Catalyst Efficiency Belo
- [11024048](https://open.wenmarpro.com/bulletins/11024048), 2025-10-08: 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 \(DTCs\):\*\* ● \*\*P0263 \- 00 Cylinder 1 Contribution/balance. ● P0266 \- 00 Cylinder 2 Contribution\-balance. ● P0269 \- 00 Cylinder 3 Contribution/balance. ● P0272 \- 00 Cylinder 4 Contribution/balance. ● P0275 \- 00 Cylinder 5 Contribution/balance. ● P0278 \- 00 Cylinder 6 Contribution/balance. ● P026B \- 00 Injection Timing Performance. ● P020A \- 00 Cylinder 1 Injection Timing. ● P020B \- 00 Cylinder 2 Injection Timing. ● P020C \- 00 Cylinder 3 Injection Timing. ● P020D \- 00 Cylinder 4 Injection Timing. ● P020E \- 00 Cylinder 5 Injection Timing. ● P020F \- 00 Cylinder 6 Injection Timing. ● P06B9 \- 00 Cylinder 1 Glow Plug Circuit Performance. ● P06BA \- 00 Cylinder 2 Glow Plug Circuit Performance. ● P06BB \- 00 Cylinder 3 Glow Plug Circuit Performance. ● P06BC \- 00 Cylinder 4 Glow Plug Circuit Performance. ● P06BD \- 00 Cylinder 5 Glow Plug Circuit Performance. ● P06BE \- 00 Cylinder 6 Glow Plug Circuit Performance. ● P0072 \- 00 Ambient Air Temperature Sensor Circuit "A" Low. ● P0087 \- 00 Fuel Rail Pressure Too Low. ● P2540 \- 00 Low Pressure Fuel System Sensor Circuit Range/Performance. ● P2543 \- 00 Low Pressure Fuel System Sensor Circuit Intermittent. ● P0100 \- 00 Mass Or Volume Air Flow Sensor "A" Circuit. ● P203F \- 00 Reductant Level Too Low. ● P0423 \- 00 Heated Catalyst Efficiency Below Threshold Bank 1. ● P20EE \- 00 SCR NOX Catalyst Efficiency Below Threshold \- Bank 1 Catalyst 1. ● P226C \- 00 Turbocharger Boost Control "A" Slow Response. ● P2281 \- 00 Air Leak Between MAF And Throttle Body. ● P229F \- 00 NOX Sensor Circuit Range/Performance \- Bank 1. ● P24DA \- 00 Particulate Matter Sensor Exhaust Sample Error Bank 1. ● P214D \- 00 SCR NOX Catalyst Outlet Temperature Too High During Particulate Filter Regeneration. ● P242B \- 00 Exhaust Gas Temperature Sensor Circuit High \- Bank 1 Sensor 3.\*\* Customers may comment on one or more of the following: ● \*\*Poor cold start performance. ● DEF level gauge slow to update after refill. ● Inverter drops out when shifting from Park to Drive.\*\* ● Check engine light illuminated. ● Cruise control drops out/cancels on its own. ● Engine stumble, runs rough, or a slight lack of power. The following software enhancements are also available: ● \*\*Improved troubleshooting and repair accuracy for air handling components through APT test available in WiTECH.\*\* ● Reduce the occurrence of false faults Diagnostic Trouble Codes \(DTCs\) P0300 and P0315. ● DTC P1451 re\-tune to reduce false faults. ● Improvements to allow DTC P2509 faults to be cleared with wiTECH. ● Adaptive Cruise Control \(ACC\) software fix to prevent cruise control dropouts. ● Engine stumble fix for improved drivability. ● Engine stall detection allowing DTC P032F to clear after a power cycle. ● Allow multiple PROXI rewrites. ● Enable cold re\-prime \(DTC P208B improvement\). This bulletin involves inspecting and possibly reprogramming the Engine Control Module \(ECM/PCM\) with the latest available software
- [11023088](https://open.wenmarpro.com/bulletins/11023088), 2025-09-10: Powertrain Contol Module Over The Air Update to V2B \(Diesel Only\) Software Version \(FOTA\) 2025 \- 2026 \(DJ\) RAM 2500 Pickup 2025 \- 2026 \(D2\) RAM 3500 Pickup 2025 \- 2026 \(DD\) RAM 3500 Cab Chassis 2025 \- 2026 \(DF\) RAM 3500 10K Lb. Cab Chassis2025 \- 2026 \(DP\) RAM 4500/5500 Cab Chassis Customers may experience one or more of the following: \- Power Inverter \(110V connection\) drops out when shifting from P to D \- DEF \(Diesel Exhaust Fluid\) level gauge inaccuracy \- Poor cold start performance \- Instrument Panel Cluste MIL \(Malfunction Indicator Light\) ON; Possible P\-codes: P0087/P2540/P2543 Fuel Pressure P214D/P242B SCR Temperature P24DA PM Sensor P20EE SCR Efficiency P226C/P2281 Mass Charge Flow P229F System Outlet NOx Sensor P0100 MAF Sensor P203F DEF Level P0423 DOC Efficiency
- [11018445](https://open.wenmarpro.com/bulletins/11018445), 2025-05-19: Diesel Exhaust Fluid \(DEF\) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code \(DTC\) P203F – Reductant Level Too Low.