Description
2004 GMC Sierra 6.6L ECM / ECU – VIN Programmed | Updated
This Engine Control Module (ECM / ECU) is a genuine OEM replacement for all 2004 GMC Sierra 6.6L models.
Each unit is VIN-programmed, updated, and fully tested for a true plug-and-play installation with our cloning service.
Built to OEM standards for reliability, calibration accuracy, and long-term performance.
Strict Testing & Quality Assurance
Every ECU is inspected, refreshed, and verified through advanced diagnostic tools. Testing includes:
Complete communication & CAN-bus verification
Sensor input/output and signal integrity checks
Injector & ignition pulse simulation
Power, ground, and load-circuit analysis
Flash memory integrity and checksum validation
Thermal and voltage-stress testing to confirm reliability
Important Note
Some vehicles with IMMO or PATS require key programming after installation. This is normal.
For a 100% plug-and-play solution, we recommend using our full cloning service. We transfer all security data to the replacement unit.
A prepaid shipping label will be emailed to you. Allow you to mail in your original computer to us for full cloning.
If cloning is not selected, the ECU will be VIN programmed, and a key relearn will be required after installation.
Contact Us
Email: info@fixecm.com
Phone: Local: 647-247-8555 | Toll-Free: 1-800-915-5566
Russell Taylor –
Super fast turnaround and the plug-and-play programming made installation a breeze. Shipping was free, which was a nice bonus.
Samuel Reed –
I was really impressed with how quickly the ECM arrived, especially with the free shipping they offered. The unit came VIN programmed and ready to install, which saved me a lot of time and hassle. The quality feels top-notch, and my 2004 GMC Sierra has been running smoothly ever since. Communication was clear throughout the process, so I always knew what to expect.