Service bulletins for the 2025 Ram 4500
A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.
262 on file from NHTSA, as of 2026-10-19.
About P1D8B on the 2025 Ram 4500: what the code means, and the bulletins and recalls about the same components.
By type
By component
By trouble code
Only bulletins with trouble code: P1D8B are shown. Show all
| 21-028-26 REV. A | 2026-05-06. Service bulletin. POWER TRAIN. 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: ● Customer is unable to switch the ignition to OFF when in Park gear. ● After shifting into Park, the Instrument Panel Cluster (IPC) will display that the transmission is in Neutral. NOTE: The transmission will actually be in Park and able to hold the vehicle, but the cluster display would indicate Neutral, preventing the engine from shutting off. ● Rough/bumpy 2-3 power on upshifts and/or 3-2 coast down shifts. ● Vehicle enters into limp home mode. Other software improvements: ● Decreased sensitivity to DTCs P1D8A and P1D8B. This bulletin involves inspecting and if required reprogramming the TCM with the latest available software |
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| 21-002-26 | 2026-01-14. Service bulletin. POWER TRAIN. 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: ● **Customer is unable to switch the ignition to OFF when in Park gear. ● After shifting into Park, the Instrument Panel Cluster (IPC) will display that the transmission is in Neutral.** NOTE: **The transmission will actually be in Park and able to hold the vehicle, but the cluster display would indicate Neutral, preventing the engine from shutting off.** ● Rough/bumpy 2-3 power on upshifts and/or 3-2 coast down shifts. ● Vehicle enters into limp home mode. Other software improvements: ● Decreased sensitivity to DTCs P1D8A and P1D8B. This bulletin involves reprogramming the TCM with the latest available software. |
| 21-039-25 REV. A | 2025-10-02. Service bulletin. POWER TRAIN. 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. 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. Other software improvements: ● Decreased sensitivity to faults P1D8A and P1D8B. This bulletin involves reprogramming the TCM with the latest available software. |
| 21-039-25 | 2025-09-24. Service bulletin. POWER TRAIN. 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. 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. Other software improvements: ● Decreased sensitivity to faults P1D8A and P1D8B. This bulletin involves reprogramming the TCM with the latest available software. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.