Cummins X15 SCR 2018-2021: OEM 5506190

Optimized NOx Control for Cummins X15 Engines (2018–2021)

What is it?
The Cummins X15 SCR (Selective Catalytic Reduction) assembly with OEM part number 5506190 is an emissions aftertreatment component designed specifically for Cummins X15 diesel engines produced between 2018 and 2021. As part of the SCR system, it works with Diesel Exhaust Fluid (DEF) to support a chemical conversion that turns nitrogen oxides (NOx) in the exhaust into nitrogen and water before the gases exit the system, helping the vehicle adhere to emissions regulations.

Why choose this SCR Assembly?
This SCR module is manufactured to Cummins’ original design guidelines for the X15 platform, ensuring proper fit and seamless interaction with DEF dosing hardware, exhaust sensors, and engine control systems. Over time, SCR effectiveness can decrease due to wear, contamination, or extended use, which may reduce NOx conversion efficiency and trigger emissions warnings. Choosing the correct OEM-specified assembly helps sustain stable emissions control and coordinated aftertreatment performance.

Key Benefits
✅ Designed for Cummins X15 aftertreatment systems (2018–2021)
✅ Helps facilitate consistent NOx conversion with DEF chemistry
✅ Supports coordinated operation with related emissions components
✅ Direct-fit replacement — no modifications needed
✅ Built for demanding exhaust environments

Applications
This SCR assembly is ideal for heavy-duty trucks and commercial vehicles equipped with Cummins X15 engines produced between 2018 and 2021. It’s commonly used in long-haul tractors, regional freight rigs, vocational trucks, and other work platforms where dependable emissions control and regulatory compliance are essential.

Installation Notes
Before servicing, make sure the exhaust and aftertreatment system has fully cooled. Remove the existing SCR module and check nearby DEF lines, sensors, and mounting hardware for signs of wear, soot buildup, or damage. Install the replacement assembly using proper seals and fasteners to ensure a secure, leak-free fit. Once installed, clear any stored fault codes and verify proper operation with diagnostic tools.

Final Thoughts
If your Cummins X15-equipped vehicle is showing NOx-related alerts, inconsistent emissions readings, or irregular aftertreatment behavior, replacing the SCR assembly with the correct OEM-specified part can help bring back steadier emissions control and more predictable system performance. The Cummins X15 SCR (OEM 5506190) plays an important role in managing regulated exhaust chemistry and supporting reliable operation across demanding duty cycles.