# Service bulletin 21\-013\-26

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.

- Type: Service bulletin
- NHTSA id: 11028243
- Published by NHTSA: 2026\-02\-04
- Manufacturer's number: 21\-013\-26
- Manufacturer's date: 2026\-01\-27
- NHTSA component: POWER TRAIN

## NHTSA's summary

Flash: Transmission Control Module \(TCM\) Updates 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. This bulletin involves inspecting and possibly reprogramming the TCM with the latest available software.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2026/MC-11028243-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2026/MC-11028243-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Transmission and driveline

## Vehicles listed

- 2025 RAM 4500
- 2025 RAM 5500

## Other bulletins for the same vehicles and component

- [08\-301\-26](/bulletins/11035976.md), 2026-08-06, Service bulletin: ELECTRICAL SYSTEM; POWER TRAIN. Flash: Electronic Shift Module \(ESM\) Updates Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must SYMPTOM: exhibit/set the following Diagnostic Trouble Code \(DTC\): ● U1057\-00 \- High Speed Fd\-Can3 Communication Bus Performance. Customers may also comment on the following: ● If the vehicle has a low or drained battery and requires a jump start, once jump started, the vehicle will not shift out of Park. This bulletin involves reprogramming the ESM with the latest available software.
- [18\-038\-26 REV. A](/bulletins/11035974.md), 2026-08-06, Service bulletin: ELECTRICAL SYSTEM; POWER TRAIN. Flash: Powertrain Control Module \(PCM\) Updates Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle exhibit/set SYMPTOM: one or more of the following Diagnostic Trouble Codes \(DTCs\): ● P219A \- Bank 1 Air\-Fuel Ratio Imbalance. ● P219B \- Bank 2 Air\-fuel Ratio Imbalance. ● P032F \- Combustion Engine Producing Insufficient Torque. NOTE: This revision has an updated and more effective fix for DTC P219B than the prior version. Customers may experience one or more of the following: ● \*\*Power Take Off \(PTO\) may cancel during engagement with high PTO loads.\*\* ● Engine speed surging, unstable, hunting, or oscillating while coasting at low vehicle speeds. ● Stationary Idle PTO feature is not activating when the user configuration is selected to require parking brake be set \(DD/DP Only\). ● PTO not auto\-resuming after hard\-wired remote start \(DD/DP Only\). ● Driveline clunk or bump when coasting to a stop in cruise control mode. ● Engine idle undershoot or delayed response with power steering input. In addition, the following software enhancement\(s\) is available: ● Increase the duration that PTO related messages are displayed on the Instrument Panel Cluster \(IPC\) \(DD/DP Only\). This bulletin involves reprogramming the PCM with the latest available software.
- [S2523000088 REV.B](/bulletins/11035086.md), 2026-07-18, Service bulletin: ELECTRICAL SYSTEM; POWER TRAIN. Vehicle Shifter Will Not Shift Out Of Park.
- [18\-066\-26](/bulletins/11035054.md), 2026-07-18, Service bulletin: ELECTRICAL SYSTEM; POWER TRAIN. Seed Request Denied During Technicians may experience the following: SYMPTOM: ● The scan tool displays the message "Seed Request denied" when attempting to reprogram the PCM to the latest available software.
- [21\-028\-26 REV. A](/bulletins/11032327.md), 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
- [S2609000005](/bulletins/11030430.md), 2026-04-01, Service bulletin: POWER TRAIN; ENGINE. Check Engine Light \(CEL\) Illuminated Diagnostic Trouble Code \(DTC\) P0381\-00 Wait to Start Lamp Inoperative
- [S2621000002](/bulletins/11029773.md), 2026-03-05, Service bulletin: POWER TRAIN. The customer concern is Service Transmission, preventing the engine from shutting off. 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
- [21\-002\-26](/bulletins/11027628.md), 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.
- [S2516000001](/bulletins/11024577.md), 2025-10-29, Service bulletin: POWER TRAIN. Driveline Vibration. Prop Shaft Diagnostic Information.
- [18\-074\-25 REV. A](/bulletins/11024054.md), 2025-10-08, Service bulletin: POWER TRAIN. Flash: Powertrain Control Module \(PCM\) Updates \*Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes \(DTCs\):\*\* ● \*\*P0263 \- 00 Cylinder 1 Contribution/balance. ● P0266 \- 00 Cylinder 2 Contribution\-balance. ● P0269 \- 00 Cylinder 3 Contribution/balance. ● P0272 \- 00 Cylinder 4 Contribution/balance. ● P0275 \- 00 Cylinder 5 Contribution/balance. ● P0278 \- 00 Cylinder 6 Contribution/balance. ● P026B \- 00 Injection Timing Performance. ● P020A \- 00 Cylinder 1 Injection Timing. ● P020B \- 00 Cylinder 2 Injection Timing. ● P020C \- 00 Cylinder 3 Injection Timing. ● P020D \- 00 Cylinder 4 Injection Timing. ● P020E \- 00 Cylinder 5 Injection Timing. ● P020F \- 00 Cylinder 6 Injection Timing. ● P06B9 \- 00 Cylinder 1 Glow Plug Circuit Performance. ● P06BA \- 00 Cylinder 2 Glow Plug Circuit Performance. ● P06BB \- 00 Cylinder 3 Glow Plug Circuit Performance. ● P06BC \- 00 Cylinder 4 Glow Plug Circuit Performance. ● P06BD \- 00 Cylinder 5 Glow Plug Circuit Performance. ● P06BE \- 00 Cylinder 6 Glow Plug Circuit Performance. ● P0072 \- 00 Ambient Air Temperature Sensor Circuit "A" Low. ● P0087 \- 00 Fuel Rail Pressure Too Low. ● P2540 \- 00 Low Pressure Fuel System Sensor Circuit Range/Performance. ● P2543 \- 00 Low Pressure Fuel System Sensor Circuit Intermittent. ● P20EE \- 00 SCR NOX Catalyst Efficiency Below Threshold \- Bank 1 Catalyst 1. ● P203F \- 00 Reductant Level Too Low. ● P2698 \- 00 Exhaust Aftertreatment Fuel Injector "A" Performance.\*\* ● P1C54 \- 00 SCR NOX Catalyst Missing. ● P056E \- 00 Cold Start Turbocharger/Supercharger Boost Control "A" Performance. ● P242F \- 00 Diesel Particulate Filter Restriction \- Ash Accumulation. ● P1451 \- 00 Diesel Particulate Filter System Performance. ● P0234 \- 00 Turbocharger Overboost Condition. ● P20E8 \- 00 Reductant Pressure Too Low. ● P208B \- 00 Reductant Pump 1 Control Performance. Customers may also comment on one or more of the following: ● \*\*Diesel Exhaust Fluid \(DEF\) level gauge inaccuracy. ● Poor cold start performance. ● Unable to initiate manual Diesel Particulate Filter \(DPF\) regen through EVIC.\*\* ● Unable to engage Power Take\-Off \(PTO\) in mobile condition while the vehicle is moving, but has no issue engaging PTO while the vehicle is stationary. ● Engine stalls under high PTO loads at high altitudes. ● PTO does not work during the split\-shaft mode. ● Engine/Cab shake during engine shutdown. ● PTO light not blinking when PTO disengaged. ● Poor engine starting performance. ● DEF level gauge fluctuations. ● In cold conditions the engine automatically increases idle speed when in Park to help with warm\-up. Once warmed up, it returns to normal idle speed. If the engine is cycling in and out of this elevated idle speed condition, the customer could complain that its not behaving properly. ● Poor alternator charging and battery life \*\*This bulletin involves inspecting and possibly reprogramming the PCM with the latest available software.\*\*

JSON: [/v1/bulletins/11028243](/v1/bulletins/11028243)

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