Thomas Bus Cummins ISB 6.7L, B6.7

Clean Emissions, Stronger Compliance: Cummins ISB 6.7L / B6.7 DEF Head Unit (2018–2024) – OEM 04-37613-000 

What is it?
The Cummins DEF Head Unit OEM 04-37613-000 is an essential emissions system component designed for ISB 6.7L and B6.7 engines from 2018 to 2024. This unit regulates the dosing and monitoring of Diesel Exhaust Fluid (DEF), ensuring the correct amount is delivered into the exhaust stream to neutralize harmful nitrogen oxides (NOx) through Selective Catalytic Reduction (SCR). It's a vital part of meeting emissions standards while maintaining smooth engine operation.

Why choose OEM 04-37613-000?
This OEM DEF head unit is specifically designed to integrate seamlessly with Cummins ISB 6.7L and B6.7 engines. It’s built to withstand harsh under-vehicle conditions, offering precise DEF flow control and accurate temperature and fluid level readings. Unlike aftermarket versions, this OEM unit is calibrated for factory accuracy and long-term durability—helping prevent SCR faults, derates, and unnecessary downtime.

Key Benefits
✅ Exact OEM fit for Cummins ISB 6.7L and B6.7 engines (2018–2024)
✅ Accurately monitors and delivers DEF for optimal NOx reduction
✅ Built to resist DEF crystallization, freezing, and corrosion
✅ Helps prevent diagnostic trouble codes and limp-mode issues
✅ Sealed connectors and robust housing for long-term reliability

Applications
The 04-37613-000 DEF head unit is used in a wide range of commercial vehicles powered by Cummins ISB 6.7L and B6.7 engines, including delivery trucks, buses, vocational equipment, and municipal service vehicles. It plays a critical role in keeping emissions systems compliant and operational in both highway and off-highway conditions.

Installation Notes
Before installation, ensure the DEF tank and surrounding area are clean to avoid contamination. Disconnect the battery and drain existing fluid if necessary. Mount the new unit carefully, ensuring seals and sensors are properly aligned. Once installed, reconnect all electrical connections securely and monitor DEF system parameters during the first engine cycle to verify function.

Final Thoughts
If your DEF system is triggering fault codes or your vehicle enters derate unexpectedly, it may be time to replace your DEF head unit. The OEM 04-37613-000 delivers factory-grade reliability and performance, helping restore emissions compliance and avoid costly repairs. Available now at Tamerx—trusted parts for hardworking engines.