RAM 3500 2025 — technical service bulletin
Bulletin 21-028-25 REV. B · NHTSA communication 11023319 · issued Sep 17, 2025
Technical service bulletin
communication type
Electrical System
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):** ● **P0827-00 Up and Down Shift Switch Circuit Low. ● P0826-00 Up and Down Shift Switch Circuit. ● P085F-00 Up and Down Shift Switch Circuit Range/Performance.** ● P1DCD-00 - TCM Monitoring Processor Performance Multiple Clutches Locked Up. Customers may also experience one or more of the following: ● **Vehicle stuck in default gear, and possibly stranded for many minutes. ● Rou
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.