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P203C on the 2016 Ram 5500

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 P203C
18003222022-10-17. Service bulletin. Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation a technician may find the following DTCs set in the PCM memory: P064F - Unauthorized Software/Calibration Detected. P218F - Reductant No Flow Detected. P202E - (Diesel Exhaust Fluid) Reductant Injector Performance. U0001-00 - CAN C BUS. P1C55 - NOx Sensor Intermittent - Bank 1 Sensor 1. P24A5 - EGR Cooler Bypass Bank 1 Control Stuck. P207F - Reductant Quality Performance. P218F - Reductant No Flow Detected. U110E - Lost Ambient Temperature Message. The following Diagnostic Trouble Codes (DTCs) have been changed from a one trip fault to a two trip fault:P2280 - Air Flow Restriction / Leak Between Air Cleaner and MAF. P203C - (Diesel Exhaust Fluid) Reductant Level Sensor Circuit Low. P208D - (Diesel Exhaust Fluid) Reductant Pump Control Circuit High. The following improvements/enhancements are also included in this software release:Fuel pressure override test improvement for wiTECH. AC pressure sensor error threshold change. No crank, No start fix. Ambient Air Temperature Improvements. Stationary de-soot with WiTECH fix.
18-092-172022-08-08. Service bulletin. Flash: 6.7L Diagnostic and System Improvements This bulletin involves reprogramming the Engine Control Module/Powertrain Control Module (ECM/PCM) with the latest available software. The following Diagnostic Trouble Codes (DTCs) have been changed from a one trip fault to a two trip fault:P2280 - Air Flow Restriction / Leak Between Air Cleaner and MAF. P203C - (Diesel Exhaust Fluid) Reductant Level Sensor Circuit Low. P208D - (Diesel Exhaust Fluid) Reductant Pump Control Circuit High. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation a technician may find the following DTCs set in the PCM memory:P218F - Reductant No Flow Detected(automatic transmission only). P202E - (Diesel Exhaust Fluid) Reductant Injector Performance(automatic transmission only). U0001-00 - CAN C BUS(automatic transmission only). P1C55 - NOx Sensor Intermittent - Bank 1 Sensor 1(automatic transmission only). P24A5 - EGR Cooler Bypass Bank 1 Control Stuck(automatic transmission only). P207F - Reductant Quality Performance. P218F - Reductant No Flow Detected. U110E - Lost Ambient Temperature Message. The following improvements/enhancements are also included in this software release:Fuel pressure override test improvement for wiTECH(automatic transmission only). AC pressure sensor error threshold change(automatic transmission only). No crank, No start fix(automatic transmission only). Ambient Air Temperature Improvements. Stationary de-soot with WiTECH fix.

2 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.