Get Your Heavy-Duty Sierra Back on the Road, Fast.
When the brain of your truck’s engine fails, everything grinds to a halt. A faulty Engine Control Module (ECM) can leave your powerful Sierra 3500 feeling weak, running rough, or even refusing to start. This isn’t just an inconvenience; it’s downtime that costs you time and money. This replacement ECM is the definitive, hassle-free solution to restore your truck’s performance and reliability. It arrives at your door fully programmed to your truck’s specific VIN, eliminating the need for expensive dealership programming or complex calibration tools. It’s a true plug-and-play fix designed to get you back to work.
Common Symptoms & Your Solution
If you’re experiencing any of the following issues, a failing ECM is the likely culprit. This unit is designed to be the direct solution for symptoms such as:
- Persistent Check Engine Light (CEL)
- Diagnostic Trouble Codes (DTCs) like P0601, P0606, or other internal processor faults
- Poor fuel economy and engine performance
- Engine stalling, sputtering, or misfiring
- Transmission shifting problems
- Complete no-start condition
Installing our expertly prepared 2012-2016 Sierra 3500 programmed ECM resolves these issues by restoring the precise factory-specified control over your engine’s fuel, spark, and emissions systems.
Features & Benefits
- ✔ Plug & Play Installation: This ECM is pre-programmed to your vehicle’s VIN. No extra dealership visits are required.
- ✔ Latest GM Software: We flash the unit with the newest, most stable software updates from General Motors for optimal performance.
- ✔ Restored Engine Performance: Get back the power, fuel efficiency, and smooth operation you expect from your 6.0L engine.
- ✔ Guaranteed Compatibility: By using your VIN, we ensure this module is a perfect match for your truck’s specific options and systems.
- ✔ Wide-Ranging Fitment: While perfect for the Sierra, this versatile module also fits a huge range of other GM vehicles, including the Silverado 2500/3500, Express/Savana vans, Cruze, Sonic, and more.
- ✔ Peace of Mind: This unit is backed by our one-year replacement warranty.
Expert Insight: The Cost of Downtime
We recently helped a fleet manager whose 2014 Sierra 3500 was completely down. The dealership quoted him over a week of lead time just to get the part, plus hours of labor for programming. Every day the truck sat, his business lost money. We were able to program and ship a replacement ECM the next day. He installed it himself in under an hour in his own shop, saving over $800 and, more importantly, getting his essential work truck back in service a week ahead of schedule. That’s the real-world value of a ready-to-install solution.
Don’t let a bad computer dictate your schedule. By providing your VIN at checkout, you’re not just buying a part; you’re buying a complete solution. This is the most efficient way to get a reliable, professionally prepared 2012-2016 Sierra 3500 programmed ECM and restore your truck to its full working potential.
Frequently Asked Questions
Do I need to do any programming myself?
No. This ECM comes fully programmed to your vehicle’s VIN with the latest GM software. It is ready for installation right out of the box. In some cases, a security relearn procedure may be required, which is a simple process that can be done without special tools.
Where do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We cannot ship the part until we have this information to program it correctly for your specific truck.
Is this compatible with other part numbers?
Yes. This ECM, part number 12668991, is a direct replacement for several other part numbers, including 12668866, 12668994, 12643636, 12663405, 12670335, and more. If your original part number is on our list, this unit will work perfectly.
Will this fix my specific problem?
This module is the solution for issues caused by a faulty ECM, such as internal processor failure codes (e.g., P0601) and other related symptoms. While it solves the most common electronic engine problems, you should always ensure your vehicle has been properly diagnosed by a qualified mechanic.
What is the difference between an ECM and a PCM?
The terms are often used interchangeably. ECM stands for Engine Control Module, while PCM stands for Powertrain Control Module. In most modern vehicles like your Sierra, the PCM controls both the engine and the transmission, so it serves both functions. This part is the correct control module for your powertrain.