RAM 2500 2019–2023 — technical service bulletin
Bulletin S2318000001 · NHTSA communication 10231739 · issued Jan 24, 2023
Technical service bulletin
communication type
Equipment
component
2019–2023
model years
15
vehicle entries
Official summary
Diagnostic Trouble Code (DTC) P1400 ? Aftermarket Calibration Detected/Warranty Coverage Confirmation Required, Setting Falsely.
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.