Cummins DEF Head Unit : OEM ASP5510-6606722

Central DEF Control Module for Cummins Engines

What is it?
The Cummins DEF Head Unit, referenced by OEM part number ASP5510-6606722, is a core component of the Diesel Exhaust Fluid (DEF) dosing system used in Cummins-equipped vehicles. This module manages DEF delivery and works with sensors and the engine control unit (ECU) to ensure precise dosing into the exhaust stream for effective NOx reduction within the Selective Catalytic Reduction (SCR) system.

Why choose this DEF Head Unit?
Designed to meet Cummins’ original specifications, the DEF head unit integrates seamlessly with Cummins aftertreatment systems, ensuring accurate DEF metering and communication with onboard sensors. When the head unit fails or becomes inconsistent, it can lead to improper DEF delivery, causing emissions warnings, reduced SCR efficiency, or unexpected system behavior. Installing the correct OEM-specified unit helps preserve reliable fluid control and balanced emissions system performance.

Key Benefits
✅ Engineered to Cummins original standards for DEF systems
✅ Facilitates accurate DEF flow control to the SCR system
✅ Enhances coordinated emissions operation with onboard sensors
✅ Direct replacement — no modifications required
✅ Built for heavy-duty duty cycles and demanding exhaust conditions

Applications
This DEF head unit is suitable for heavy-duty trucks, commercial vehicles, and equipment powered by Cummins engines equipped with SCR systems that require precise DEF metering. It’s commonly found in over-the-road tractors, vocational rigs, regional haulers, and other diesel applications where emissions control and NOx reduction are essential to operation.

Installation Notes
Before servicing, ensure the aftertreatment system is fully cooled to avoid injury or component damage. Disable the vehicle’s ignition and disconnect the battery. Carefully disconnect DEF supply and return lines, electrical connectors, and mounting hardware from the existing head unit. Inspect all lines, seals, and connectors for wear or contamination before installing the replacement. Position the new DEF head unit, secure it with proper fasteners, and reconnect all lines and electrical connections. After installation, clear any stored fault codes and verify accurate DEF dosing with appropriate diagnostic tools.

Final Thoughts
If your Cummins-equipped vehicle is experiencing DEF-related warnings, inconsistent NOx conversion, or irregular aftertreatment behavior, replacing the DEF head unit with the correct OEM-specified assembly can help restore dependable fluid control and coordinated emissions performance. The Cummins DEF Head Unit (OEM ASP5510-6606722) plays a central role in regulated exhaust treatment and supports reliable operation across diverse duty cycles.