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.Built to OEM standards for reliability, calibration accuracy, and long-term performance.
Strict Testing & Quality Assurance
This is not a brand-new unit. It is a rebuilt unit that is inspected, refreshed, and fully tested before shipping.
Testing includes communication, CAN-bus, sensor signal, power circuit, flash memory, and reliability checks.
Important Note
If your vehicle does not have an IMMO or PATS system, this unit will be directly plug&play.
If your vehicle has an IMMO or PATS system, it will require a key relearn after installation. You can visit your local locksmith for help.
We also offer a full cloning service. We transfer all security data to the replacement unit, so it will be a plug&play installation.
For all European cars, Hyundai, and Kia vehicles, we recommend adding our cloning service as a bundle.
For American and Japanese cars, we recommend doing a key relearn on-site.
Contact Us
Email: info@fixecm.com
Phone: Local: 647-247-8555 | Toll-Free: 1-800-915-5566
Mason Russell –
I needed a replacement ECM for my 2004 GMC Sierra 6.6L and was really impressed with how easy the whole process went. The unit arrived quickly, and I appreciated that the VIN programming was already done before shipping—made installation plug-and-play. The communication from the seller was top notch; they kept me informed every step of the way and answered my questions promptly. It feels like a solid, reliable part and has my truck running better than before. Definitely recommend this seller if you want a hassle-free experience.
Samuel Jenkins –
The ECU arrived quickly with free shipping and was already programmed for my 2004 GMC Sierra—plug-and-play made installation a breeze. Communication was spot on, and they answered all my questions right away.
Owen Reynolds –
I was a bit nervous about ordering an ECM online for my 2004 GMC Sierra, but this purchase exceeded my expectations. The module arrived quickly, and I appreciated the free shipping which saved me some extra cost. What really stood out was the plug-and-play setup—they had the ECM programmed specifically for my VIN before it shipped, so installation was straightforward with no hiccups. The quality of the part is top-notch, and my truck runs smoother than ever. I would definitely buy from them again if the need arises.
Grant Collins –
The 12210729 ECM for my 2004 GMC Sierra arrived quickly and was exactly as described. Installation was straightforward since it was plug-and-play, which saved me a lot of hassle and money compared to taking it to the dealer. The communication from the seller was clear and professional throughout the process. Overall, it was a smooth experience and the truck runs perfectly now.
Isaac Stewart –
Fast shipping and plug-and-play installation made this ECM swap effortless, and the price saved me a ton compared to the dealer. Highly recommend for anyone looking to avoid dealer hassles.
Chris Bailey –
I purchased the 12210729 ECM for my 2004 GMC Sierra, and the whole process was straightforward thanks to their professional VIN programming service. The unit arrived quickly with free shipping, which was a nice bonus. Everything worked perfectly right out of the box, and the communication from the team was excellent—they kept me informed every step of the way. Definitely a reliable source for quality parts and service.