RAM 2500 2019–2021 — technical service bulletin
Bulletin 18-034-21 · NHTSA communication 10194039 · issued Apr 2, 2021
Technical service bulletin
communication type
Fuel System, Diesel
component
2019–2021
model years
9
vehicle entries
Official summary
P203E and P203F Additional Diagnostic Information This bulletin provides additional information regarding diagnosing Diesel Exhaust Fluid (DEF) issue in extreme cold weather. Diagnostic Trouble Codes (DTCs) P203E - Reductant Level Sensor 1 Circuit Intermittent and/or P203F - Reductant Level Too Low set.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.