Get Your Duramax Back on the Job, Fast.
When the Engine Control Module (ECM) in your Sierra, Silverado, or Savana van fails, your work grinds to a halt. A faulty ECM can mean a truck that won’t start, runs rough, or throws confusing codes, costing you valuable time and money. This direct-fit replacement ECM is the reliable, no-nonsense solution to get your 6.6L Duramax diesel back to peak operational status. We pre-program the module to your vehicle’s specific VIN with the latest GM software updates, eliminating the need for an expensive trip to the dealership for initial programming.
Common Duramax ECM Failure Symptoms & Your Solution
If you’re experiencing any of the following, a failing ECM is the likely culprit. This module is the definitive solution for:
- Complete no-start or intermittent starting conditions
- Engine stalling or cutting out unexpectedly
- Check Engine Light (CEL) with communication-related DTCs (e.g., U0100)
- Error codes for internal processor failure (e.g., P0601, P0606)
- Poor engine performance, reduced power, and decreased fuel economy
- Transmission shifting issues or erratic behavior
Installing this professionally programmed 12658036 ECM 6.6L Duramax restores the critical link between your engine’s sensors and its performance, ensuring every component works in perfect harmony as the factory intended.
Features & Benefits
- ✔ VIN-Specific Programming: Arrives flashed with the latest GM software for your exact vehicle. Just provide your VIN, and we handle the rest, saving you time and programming costs.
- ✔ Restored Engine Performance: Regain the power, throttle response, and fuel efficiency your Duramax is known for.
- ✔ Direct-Fit Replacement: Engineered to be a perfect match for the original unit (replaces part numbers 12658036 and 12667377), ensuring a straightforward installation with no modifications required.
- ✔ Solves Frustrating Electrical Issues: Eliminates false sensor codes and communication errors caused by a faulty original computer.
- ✔ Purchase with Confidence: This unit is backed by our one-year replacement warranty.
An Expert’s Note on Duramax Electronics
The ECM in a modern 6.6L Duramax is more than just a computer; it’s the central command center for your entire powertrain. It manages everything from precise fuel injection timing and turbocharger boost to transmission shift points and emissions systems. That’s why simply installing a used, unprogrammed module is a recipe for disaster. Our process ensures your new 12658036 ECM 6.6L Duramax has the correct, updated factory calibration file for your specific VIN, which is the foundation for a successful and lasting repair.
Take control of your repair and minimize your vehicle’s downtime. By ordering this pre-programmed 12658036 ECM 6.6L Duramax, you’re not just buying a part; you’re investing in a reliable solution that gets your truck back to work.
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, you will need to send us a message with your vehicle’s 17-digit VIN. We cannot ship your order until we receive this information, as the programming is specific to your truck.
What is a “theft relearn” and will I need to do one?
A vehicle anti-theft system (VATS) relearn synchronizes the new ECM with your vehicle’s security system and keys. In many cases, this procedure is required after installation for the engine to start. This must be performed on-site by the installer using a compatible, professional-grade scan tool or the GM TIS2Web system. This is the responsibility of the buyer/installer.
Is this a direct replacement for part number 12667377?
Yes. This ECM, primary part number 12658036, is the correct, updated service replacement for units marked with 12667377. It is fully compatible with all vehicles listed in the fitment chart.
Does this ECM require any additional programming?
We handle the initial programming (flashing) to your VIN before shipment. However, on-vehicle relearn procedures, such as the security relearn, crankshaft position variation learn, and injector flow rate programming, must be completed by the installer after the part is in the vehicle.
What happens if I don’t perform the required relearn procedures?
Failure to perform necessary relearns can result in a no-start condition (from the security system), a check engine light, or suboptimal engine performance. It is a critical final step in the installation process.
How can I be sure this fits my truck?
Please review the detailed fitment list provided in this listing. This part is designed for the 2014-2015 model year GM trucks and vans equipped with the 6.6L Duramax diesel engine. Matching your vehicle and original part number is the best way to guarantee compatibility.