# Service bulletin 18\-074\-25

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: 11021560
- Published by NHTSA: 2025\-08\-06
- Manufacturer's number: 18\-074\-25
- Manufacturer's date: 2025\-08\-01
- NHTSA component: UNKNOWN OR OTHER

## NHTSA's summary

Flash: Powertrain Control Module \(PCM\) Updates Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle may exhibit/set one or more of the following Diagnostic Trouble Codes \(DTCs\): ● 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: ● 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. ● Diesel Exhaust Fluid \(DEF\) 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 reprogramming the PCM with the latest available software.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11021560-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11021560-9999.pdf)

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

## Trouble codes named

P0234, P056E, P1451, P1C54, P208B, P20E8, P242F

## Vehicles listed

- 2025 RAM 4500
- 2025 RAM 5500

JSON: [/v1/bulletins/11021560](/v1/bulletins/11021560)

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