RAM 2500 2019–2024 — technical service bulletin
Bulletin 25-008-24 · NHTSA communication 11010636 · issued Nov 14, 2024
Technical service bulletin
communication type
Unknown OR Other
component
2019–2024
model years
24
vehicle entries
Official summary
"Flash: Diesel Exhaust Fluid (DEF) Dosing Control Unit (DCU) Update Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set the following Diagnostic Trouble Code (DTC): ● P21C4-00 - Reductant Line Heater Relay Control Circuit High. ● U11C1-00 - Reductant Control Module Received Implausible Data From ECM/PCM. These DTCs will occur after installation of service DCU 68458603AB. This bulletin involves reprogramming the DCU with the latest available software."
Vehicles covered
- 2019 RAM 2500
- 2020 RAM 2500
- 2021 RAM 2500
- 2022 RAM 2500
- 2023 RAM 2500
- 2024 RAM 2500
- 2019 RAM 3500
- 2020 RAM 3500
- 2021 RAM 3500
- 2022 RAM 3500
- 2023 RAM 3500
- 2024 RAM 3500
- 2019 RAM 4500
- 2020 RAM 4500
- 2021 RAM 4500
- 2022 RAM 4500
- 2023 RAM 4500
- 2024 RAM 4500
- 2019 RAM 5500
- 2020 RAM 5500
- 2021 RAM 5500
- 2022 RAM 5500
- 2023 RAM 5500
- 2024 RAM 5500
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.