Get Your Workhorse Back on the Road, Fast.
A failed Engine Control Module (ECM) in your Sierra, Silverado, Express, or Savana isn’t just an inconvenience—it’s a roadblock that costs you time and money. When your 6.6L Duramax is down, your business or project is down. This Engine Control Module is the definitive, professional solution to restore your vehicle’s performance and get your reliable workhorse back in service, operating exactly as the factory intended.
Common Symptoms of a Failing ECM & Your Solution
If your truck or van is experiencing issues like a no-start condition, erratic engine behavior, stalling, poor fuel economy, or a check engine light with communication-related diagnostic trouble codes (DTCs) like U0100, a faulty ECM is the most likely culprit. Don’t let these problems sideline your vehicle. Our solution directly addresses the core of the issue.
This is not a generic, off-the-shelf computer. We provide a genuine GM ECM, part number 12658036, which is also a direct replacement for part number 12667377. It comes professionally flashed with the latest GM software updates specific to your vehicle’s VIN. This critical step ensures perfect compatibility and restores the complex logic your engine needs for optimal power, efficiency, and reliability. By installing our programmed 12658036 ECM, you are directly addressing the root cause of these frustrating and costly electronic failures.
Features & Benefits:
- ✔ VIN-Specific Programming: We flash the module to your exact VIN before shipping, ensuring 100% compatibility with your vehicle’s systems and options.
- ✔ Loaded with Latest GM Updates: Your ECM arrives with the most current factory software, often improving performance and addressing known issues from the original calibration.
- ✔ Direct-Fit OEM Part: This module meets all original equipment specifications for a straightforward installation in the factory location.
- ✔ Eliminate Costly Downtime: Avoid long waits and high programming fees at the dealership. We handle the complex part, so you can get back to work faster.
- ✔ Restored Engine Performance: A correctly functioning ECM is essential for proper fuel delivery, ignition timing, and transmission control, restoring the power and dependability you rely on.
- ✔ Peace of Mind: This unit is backed by our one-year replacement warranty.
A Technician’s Note on Installation
From over 20 years of hands-on diagnostics, I can tell you that the single biggest mistake people make with ECM replacement is improper programming. A mismatched calibration can cause more problems than it solves. That’s why we handle the critical programming for you before it ever leaves our facility. Please be aware that for these GM trucks, a security relearn is often a necessary final step after installation. It’s a standard procedure that pairs the new ECM to your vehicle’s anti-theft system. This is not a defect, but a required handshake between components. Taking the time to perform this relearn is the key to a successful, one-time repair with your programmed 12658036 ECM.
Frequently Asked Questions
How do I provide my Vehicle Identification Number (VIN)?
After you complete your purchase, simply send us a message with your 17-digit VIN. We cannot program and ship your ECM without this information, so please provide it promptly to avoid delays.
What is a ‘theft relearn’ and will I need to do it?
A theft relearn, or security relearn, synchronizes the new ECM with your vehicle’s anti-theft system (Pass-Key/Pass-Lock). If the vehicle does not start after installation, this procedure is required. It is the buyer’s responsibility and requires a professional scan tool with GM programming capabilities, such as the GM TIS2Web system.
Is this a plug-and-play part?
Because we pre-program it to your VIN, it is as close as it gets. However, due to the integrated anti-theft systems on these vehicles, you must be prepared to perform the security relearn procedure. Other vehicle-specific relearns, like crankshaft position variation or injector flow rate programming, may also be necessary.
Will this ECM fix my specific problem?
This programmed 12658036 ECM will resolve issues directly caused by a faulty engine computer. While it fixes a wide range of problems, we always recommend a proper diagnosis by a qualified technician to confirm the ECM is the point of failure before ordering.
Does this part number replace any others?
Yes, this ECM part number 12658036 is a direct, updated replacement for the older part number 12667377. It is the correct module for all vehicles listed in the fitment chart.
What vehicles does this ECM fit?
This module is for 2014-2015 Chevrolet Express/Silverado HD and GMC Savana/Sierra HD models equipped with the 6.6L Duramax diesel engine. Please verify the part number and check the detailed fitment list to ensure it is correct for your specific vehicle.