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P203B on the 2015 Ram 4500

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 P203B
25001152023-01-09. Service bulletin. Diesel Exhaust Fluid (DEF) Level Gauge Inaccurate Or Stuck This bulletin involves verifying the correct DEF level in the tank and if necessary, replacing the DEF pump module. A small number of customers may comment that their DEF level gauge is stuck for long periods of time or is erratic. The customer may also experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation a technician may find one or more of the following Diagnostic Trouble Codes (DTCs). ? P203B - Reductant Level Sensor Circuit Performance ? P203C - (Diesel Exhaust Fluid) Reductant Level Sensor Circuit Low. ? P203D - (Diesel Exhaust Fluid) Reductant Level Sensor Circuit High.
25-001-15 REV-A2018-11-26. Service bulletin. Diesel Exhaust Fluid (DEF) Level Sensor Manufacturing Defect This bulletin involves replacing the DEF pump module. A manufacturing defect in the level sensor may have occurred, if the level sensor was built within the time frame listed above. There may be a Malfunction Indicator Lamp (MIL) illuminated. Upon further investigation a technician may find one or more of the following Diagnostic Trouble Codes (DTCs). ? P203B - Reductant Level Sensor Circuit Performance. ? P203C - (Diesel Exhaust Fluid) Reductant Level Sensor Circuit Low. ? P203D - (Diesel Exhaust Fluid) Reductant Level Sensor Circuit High.
25-001-152018-11-26. Service bulletin. Diesel Exhaust Fluid (DEF) Level Gauge Inaccurate Or Stuck This bulletin involves verifying the correct DEF level in the tank and if necessary, replacing the DEF pump module. A small number of customers may comment that their DEF level gauge is stuck for long periods of time or is erratic. The customer may also experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation a technician may find one or more of the following Diagnostic Trouble Codes (DTCs). ? P203B - Reductant Level Sensor Circuit Performance ? P203C - (Diesel Exhaust Fluid) Reductant Level Sensor Circuit Low. ? P203D - (Diesel Exhaust Fluid) Reductant Level Sensor Circuit High.

3 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.