Cummins ISB 6.7L, B6.7, ISL DEF Head Unit 2014-2015: OEM 04-30774-001

DEF Tank Control Module for Cummins ISB 6.7L, B6.7 & ISL Engines (2014–2015)

What is it?
The Cummins DEF Head Unit, identified by OEM 04-30774-001, is a multi-function component mounted on the Diesel Exhaust Fluid (DEF) tank for engines produced between 2014 and 2015. This unit integrates sensors and fluid delivery functions, allowing it to monitor DEF level, temperature, and quality while also managing fluid supply to the aftertreatment system.

It plays a central role in ensuring DEF is available and properly delivered to support emissions reduction through the SCR system.

Why choose this DEF Head Unit?
DEF systems rely on accurate monitoring and steady fluid movement to function correctly. The OEM 04-30774-001 head unit is designed for Cummins ISB 6.7L, B6.7, and ISL platforms, helping ensure proper communication between the DEF tank and the engine control module (ECM).

This unit continuously tracks DEF conditions and helps regulate fluid delivery for emissions control. If it becomes faulty, it can lead to incorrect readings, warning lights, or engine derate conditions due to improper DEF management.

Replacing it helps restore proper system feedback, ensuring the SCR system receives the correct DEF input for consistent operation.

Key Benefits
✅ OEM-matched DEF head unit for Cummins ISB 6.7L, B6.7, and ISL engines
✅ Monitors DEF level, temperature, and fluid quality
✅ Supports proper DEF delivery to the aftertreatment system
✅ Helps maintain accurate communication with the ECM
✅ Direct-fit design for proper tank integration

Applications
This DEF head unit is used on diesel engines equipped with Cummins ISB 6.7L, B6.7, and ISL platforms manufactured from 2014 through 2015. These engines are commonly found in medium- and heavy-duty trucks, commercial fleets, and vocational vehicles that rely on SCR systems for emissions compliance.

Installation Notes
Before starting service, ensure the DEF tank level is safe for removal. Disconnect the electrical connectors and remove the existing head unit from the tank. Inspect the tank opening, seals, and surrounding components for contamination or crystallized DEF residue. Install the replacement unit with proper sealing to prevent leaks, reconnect all connections, and verify accurate system readings using diagnostic tools.

Final Thoughts
Proper DEF management is essential for maintaining emissions system performance. The Cummins DEF Head Unit (OEM 04-30774-001) provides the monitoring and delivery functions needed to keep the SCR system operating correctly, helping support consistent emissions control and dependable engine operation.