Emissions Control You Can Trust: Blue Bird Cummins ISB 6.7L / B6.7 DEF Head Unit – 2018–2024
What is it?
The Blue Bird Cummins ISB 6.7L / B6.7 DEF Head Unit is a critical component in the Selective Catalytic Reduction (SCR) system of modern Blue Bird buses. This unit is responsible for monitoring and delivering Diesel Exhaust Fluid (DEF) into the exhaust stream, reducing harmful NOx emissions in compliance with EPA regulations. It integrates key functions such as fluid level sensing, temperature monitoring, and DEF dosing—all essential for proper aftertreatment system operation.
Why choose a Blue Bird-specific DEF Head Unit?
Designed specifically for Blue Bird buses equipped with Cummins ISB 6.7L and B6.7 engines, this unit ensures precise communication with the engine control module (ECM). It provides reliable DEF delivery under all operating conditions, helping prevent SCR faults, engine derates, and system failures. Using an application-specific unit means no guesswork, no retrofit modifications, and full compatibility with Blue Bird’s emissions system architecture.
Key Benefits
✅ Tailored fit for Blue Bird buses running Cummins ISB 6.7L / B6.7 engines
✅ Accurately regulates DEF dosing for clean and efficient emissions reduction
✅ Equipped with integrated sensors for fluid level, temperature, and pressure
✅ Built with weather-sealed connectors and durable housing for harsh conditions
✅ Prevents costly SCR system malfunctions and limp-mode scenarios
Applications
This DEF head unit is built for Blue Bird school and commercial buses from 2010 through 2024 equipped with Cummins ISB 6.7L and B6.7 engines. These buses rely on consistent DEF system performance to meet emissions compliance, especially under heavy stop-and-go conditions typical of daily routes.
Installation Notes
Before replacing the unit, disconnect the battery and depressurize the DEF system. Ensure the DEF tank is clean and free of crystallization. Mount the new unit securely, connect the sensors and lines using OEM-style fittings, and bleed any air from the system if necessary. After installation, reset any active fault codes and verify DEF flow and sensor readings using a diagnostic tool.
Final Thoughts
When your Blue Bird bus throws SCR or DEF-related fault codes, don’t take chances. Replace your unit with a compatible, emissions-grade DEF Head Unit built for Cummins ISB 6.7L / B6.7 engines. It’s your best defense against downtime, derates, and compliance issues. Available now at Tamerx—quality you can depend on, shipped fast.