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Service bulletins for the 2026 Ram 5500

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

182 on file from NHTSA, as of 2026-10-19.

About P203F on the 2026 Ram 5500: what the code means, and the bulletins and recalls about the same components.

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Only bulletins with trouble code: P203F are shown. Show all

Bulletins, newest first
S2525000002 REV.B2026-04-10. Service bulletin. UNKNOWN OR OTHER. Diesel Exhaust Fluid (DEF) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code (DTC) P203F – Reductant Level Too Low.
S2525000002 REV.A2026-02-19. Service bulletin. FUEL/PROPULSION SYSTEM. Diesel Exhaust Fluid (DEF) Gauge Fluctuates Or Is Erratic. Diagnostic Trouble Code (DTC) P203F – Reductant Level Too Low.
18-012-26 REV.A2026-02-12. Service bulletin. ENGINE; ELECTRICAL SYSTEM. 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): ● 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. ● P20EE-00 - SCR Nox Catalyst Efficiency Below Threshold - Bank 1 Catalyst 1. ● P203F-00 - Reductant Level Too Low. ● P2698-00 - Exhaust Aftertreatment Fuel Injector "A" Performance. ● 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: ● Diesel Exhaust Fluid (DEF) level gauge inaccuracy. ● Poor cold start performance. ● Unable to initiate manual Diesel Particulate Filter (DPF) regen through Electronic Vehicle Information Center (EVIC). ● While using the remote Power Take-Off (PTO) feature, the PTO may not engage or resume operation properly, after disengaging: 1. Engine is running with PTO engaged. 2. Operator is using the equipment, for example a bucket attachment. 3. Operator gets in position, then uses remote start/stop button to turn truck off while they perform a task. 4. The task is completed, then operator is ready to move the bucket so they use remote start/stop to start the engine. 5. The engine starts but PTO does not automatically re-engage so the equipment doesn’t operate. This bulletin involves inspecting and possibly reprogramming the PCM with the latest available software.
18-012-262026-02-04. Service bulletin. ELECTRICAL SYSTEM. NOte: Revision is being created to correct the Models affected. 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): ● 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. ● P20EE-00 - SCR Nox Catalyst Efficiency Below Threshold - Bank 1 Catalyst 1. ● P203F-00 - Reductant Level Too Low. ● P2698-00 - Exhaust Aftertreatment Fuel Injector "A" Performance. ● 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: ● Diesel Exhaust Fluid (DEF) level gauge inaccuracy. ● Poor cold start performance. ● Unable to initiate manual Diesel Particulate Filter (DPF) regen through Electronic Vehicle Information Center (EVIC). ● While using the remote Power Take-Off (PTO) feature, the PTO may not engage or resume operation properly, after disengaging: 1. Engine is running with PTO engaged. 2. Operator is using the equipment, for example a bucket attachment. 3. Operator gets in position, then uses remote start/stop button to turn truck off while they perform a task. 4. The task is completed, then operator is ready to move the bucket so they use remote start/stop to start the engine. 5. The engine starts, but PTO does not automatically re-engage so their equipment doesn’t operate. This bulletin involves inspecting and possibly reprogramming the PCM with the latest available software.
OTHERDOC_1472025-09-10. Over-the-air update. ELECTRICAL SYSTEM. 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

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.