Freightliner Cummins ISB 6.7L, ISL, L9 DEF Head Unit

Emissions Precision for Freightliner Cummins – OEM DEF Head Unit (04‑30774‑005), 2014–2016

What is it?
The OEM 04‑30774‑005 DEF Head Unit is a factory‑specified header assembly for Freightliner trucks equipped with Cummins ISB 6.7L, ISL, or L9 engines within the model years 2014 through 2016. This unit is mounted on the DEF tank and houses sensors that monitor fluid level, temperature, and interfaces with the SCR (Selective Catalytic Reduction) system to maintain emissions compliance.

Why choose this OEM DEF Head Unit?
This genuine unit is built to Cummins and Freightliner OEM specifications, ensuring accurate sensor calibration, perfect sealing, and seamless compatibility with factory DEF system wiring and diagnostics. Installing the correct OEM part helps avoid warning codes, erratic readings, leaks, or SCR performance interruptions that often arise from non‑OEM or mismatched replacements.

Key Benefits
 ✅ Drop‑in fit for Freightliner trucks with Cummins ISB 6.7L, ISL, or L9 (2014–2016)
 ✅ Accurate DEF fluid level and temperature monitoring
 ✅ Sealed construction to prevent leaks and contamination
 ✅ Supports factory diagnostics and emission control protocols
 ✅ Rugged design suited for sustained duty and system stress

Applications
Used in Freightliner vocational, regional, and highway trucks using Cummins ISB, ISL, or L9 engines from 2014 to 2016. It’s an essential component in fleets where DEF system reliability and emissions compliance are necessary for daily operation.

Installation Notes
Installation should be performed by a qualified technician. Begin by depressurizing or isolating the DEF system. Clean the DEF tank opening and mount surfaces thoroughly. Replace any worn gaskets or O‑rings. Install the head unit and torque it to OEM specifications. Afterward, use diagnostic tools to confirm correct sensor outputs, check for leaks, and clear any DEF or SCR fault codes to ensure proper functionality.

Final Thoughts
If your Freightliner is exhibiting DEF‑related errors, fluid reading problems, or sensor malfunctions, the OEM 04‑30774‑005 DEF Head Unit is the reliable fix. With factory‑level design, proper calibration, and durable construction, it restores accurate DEF system function and helps maintain your fleet’s emissions compliance and reliability.