When your Silverado, Sierra, or Express van is down, your entire workday grinds to a halt. A faulty Engine Control Module (ECM) can cause a host of frustrating issues, from no-start conditions to poor performance and persistent check engine lights. This pre-programmed ECM is the definitive, professional-grade solution to get your 6.6L diesel engine running reliably again, minimizing downtime and getting you back on the road.
Common Symptoms & Your Solution
If your heavy-duty GM vehicle is experiencing issues like intermittent stalling, complete failure to start, erratic transmission shifting, or diagnostic trouble codes pointing to internal module failure (like P0606), the ECM is a primary suspect. This isn’t just a replacement part; it’s a direct solution. We program this genuine GM 12658036 ECM specifically to your vehicle’s VIN, ensuring it arrives with the latest factory software updates for optimal performance and efficiency. It directly replaces alternate part number 12667377 as well.
- ✔ Flashed to Your VIN: We handle the complex programming for you. This module arrives ready for installation and the final vehicle relearn procedures, saving you a trip to the dealer.
- ✔ Updated GM Calibrations: Your ECM comes loaded with the newest software from General Motors, addressing potential factory bugs and improving overall engine performance and fuel management.
- ✔ Guaranteed Compatibility: A perfect fit for 2015 Sierra, Silverado, Express, and Savana models with the 6.6L engine, ensuring a seamless installation.
- ✔ Restore Peak Performance: Eliminate frustrating drivability issues and restore the power and dependability you rely on for heavy-duty work.
- ✔ One-Year Replacement Warranty: This unit is backed by our one-year replacement warranty for your peace of mind.
Expert Technician’s Note: As a veteran technician, I’ve seen many jobs get complicated by skipping the final steps. After installing your new 12658036 ECM, performing the vehicle’s security or ‘theft deterrent’ relearn is a non-negotiable step. It’s how the new ECM ‘shakes hands’ with the rest of your truck’s security modules. While it requires specific tools like GM’s TIS2WEB, it’s the critical final step to ensure the engine will start and run. Taking care of this, along with any other required setups like injector flow rate programming, is the mark of a professional job done right.
Frequently Asked Questions
What information do you need from me after I order?
After you complete your purchase, you must provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). This is essential for us to load the correct GM software and calibrations for your specific truck or van.
Will my vehicle start immediately after I install this ECM?
In most cases, no. You will need to perform a vehicle theft deterrent system relearn. This is a standard security procedure required by GM that pairs the new ECM to your vehicle. Without it, the security system will prevent the engine from starting.
What tools are needed for the final setup?
The security relearn procedure requires a professional-grade scan tool or access to the GM programming system, TIS2WEB. This is the responsibility of the installer. Other procedures, like a crankshaft position sensor variation relearn, may also be necessary depending on the vehicle.
Do I need to send my old computer to you?
No, there is no core charge or need to send in your old module. This is a direct purchase of a replacement 12658036 ECM that has been prepared for your vehicle.
Is this a simple plug-and-play part?
While it is a direct physical fit (‘plug-in’), it is not ‘play’. The initial programming is done by us, but the final installation requires the mandatory security relearn procedure to be performed on the vehicle for it to function.