LLY Bench Harness

LLY Duramax Bench Harness – Simplify Your Tuning Process

Take the guesswork out of tuning your 2004–2005 LLY Duramax ECM with our LLY Bench Harness. Whether you’re flashing tune files, unlocking an ECM, or diagnosing issues, this harness is designed to give you a clean, stable connection directly from your ECM to your tuning hardware or bench programmer.

Why Use a Bench Harness?
Tuning through the OBDII port can introduce errors caused by electrical interference from aftermarket accessories, low battery voltage, or the need to pull specific fuses. Our LLY Bench Harness eliminates these problems by powering the ECM independently of the truck. This provides a stable and direct communication link — reducing the chance of bricking your ECM during a flash.

Key Features:

• Compatible with 2004–2005 LLY Duramax ECMs

• Avoid tuning errors caused by truck-side power fluctuations or interference

• No need to pull radio, ABS, or other fuses

• Works with EFI Live, HP Tuners, and other tuning platforms

• Plug-and-play connectors for easy setup on your workbench

Whether you’re a professional tuner or a weekend warrior, the LLY Bench Harness gives you the reliability and control you need when flashing or diagnosing your ECM.