RAM 3500 2025 — technical service bulletin
Bulletin 21-042-25 · NHTSA communication 11024306 · issued Oct 11, 2025
Technical service bulletin
communication type
Power Train
component
2025
model years
1
vehicle entries
Official summary
Flash: Transmission Control Module (TCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0826-00 - Up/Down Shift Switch. ● P0827-00 - Up/down Shift Switch Circuit Low. ● P085F-00 - Up And Down Shift Switch Circuit Range/performance. Customers may also experience one or more of the following: ● Vehicle stuck in default gear, and possibly stranded for many minutes. ● Rough/bumpy 2-3 power on upshifts and/or 3-2 coast down shifts. ● Vehicle enters into limp home mode.
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.