Is Your GM Vehicle Experiencing Unexplained Performance Issues?
The Engine Control Module (ECM), often called the vehicle’s main computer, is the central nervous system of your engine’s operation. It meticulously manages everything from fuel injection and ignition timing to emissions systems and transmission shifting. When the ECM begins to fail, it can cause a cascade of confusing and frustrating problems, often leading to a vehicle that is unreliable or completely undrivable. If you’re dealing with a persistent Check Engine Light, poor fuel economy, or erratic engine behavior in your Cadillac ATS, Silverado, Sierra, or other compatible GM model, a faulty ECM is a very likely culprit.
This is a genuine GM Engine Control Module, part number 12663391, which serves as a direct replacement for a wide range of vehicles. The most critical aspect of replacing an ECM is the programming. This isn’t a part you can simply pull from a box and install. Our service eliminates the need for an expensive trip to the dealership by programming this module specifically to your vehicle’s Vehicle Identification Number (VIN) before it ships. We load the latest, most stable software updates from GM, ensuring optimal performance, fuel efficiency, and emissions compliance right out of the box.
From the Diagnostic Bay
We had a 2015 GMC Sierra 1500 come into the shop with a complaint that was driving the owner crazy. The truck would randomly stall at stoplights, the check engine light would flicker on and off with no stored codes, and the fuel mileage had dropped significantly. The owner had already replaced the spark plugs, ignition coils, and even a mass airflow sensor at another shop with no success. After hooking up our professional scan tool and monitoring live data, we noticed erratic voltage readings from several key sensors, but the sensors themselves tested fine. This pointed us directly to the ECM. The internal voltage regulator was failing intermittently, causing the processor to send faulty commands. We installed one of our VIN-programmed ECMs, performed the quick security relearn, and the truck ran perfectly. It was a classic case where the ‘brain’ was the problem, not the ‘body’.
Common Symptoms of a Failing Engine Control Module
- ✔ Persistent Check Engine Light (CEL) that won’t clear or returns immediately.
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ A noticeable decrease in fuel economy.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Poor acceleration or a general lack of power.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Issues with other electronic modules, as the ECM is a central communication hub.
Why Choose Our Programmed 2014-2016 ATS ECM?
Replacing the ECM on modern vehicles is a complex job that requires specialized tools and software. We simplify this entire process for you. By providing us with your VIN during checkout, you receive a module that is ready for installation. This plug-and-play solution means no additional programming is required by a dealer or specialized mechanic, saving you hundreds of dollars in labor and towing fees. We ensure your new 2014-2016 ATS ECM is loaded with the correct factory software for your specific vehicle configuration, including engine type, transmission, and emissions equipment. This guarantees a seamless integration and restores your vehicle’s factory performance and reliability.
Installation and Compatibility
Installation is straightforward for anyone with basic mechanical skills. After disconnecting the battery, simply locate and unbolt the old ECM, disconnect the wiring harnesses, and install the new module in its place. Once installed and the battery is reconnected, you may need to perform a simple security relearn procedure (often called a Passlock or Passkey relearn), which typically involves turning the key on and off in a specific sequence. Instructions for this procedure are widely available online for your specific model.
This module is a direct replacement for multiple part numbers, ensuring broad compatibility. Please verify your part number against this list: 12692067, 12676230, 12656993, 12662034, 12672537, 12673195, 12663391, 12672963, 12669318. It fits a wide variety of GM cars and trucks, including but not limited to the Cadillac ATS, CTS, Escalade, XTS; Chevrolet Silverado, Corvette, Camaro, Colorado, Suburban, Tahoe; and GMC Sierra, Canyon, and Yukon models from 2014-2016. Always confirm fitment for your specific vehicle before ordering.
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, you will receive instructions to send us your 17-digit Vehicle Identification Number (VIN). We cannot ship your part until we receive this information, as the programming is essential for the module to function in your vehicle.
Is this a plug-and-play part?
Yes, for the most part. Because we program the module to your VIN, it eliminates the need for dealer-level programming tools. However, on most GM vehicles, you will need to perform a security relearn procedure after installation. This procedure can typically be done by you and does not require a scan tool.
Will this ECM fix my vehicle’s problem?
This ECM will correct issues directly caused by a faulty engine computer. While the symptoms listed are common for ECM failure, they can also be caused by other failing components. Proper vehicle diagnosis is always recommended before ordering to ensure you are purchasing the correct part for your needs.
Do I need to send my old ECM back?
No core charge is required for this part. You do not need to return your old, non-functional engine control module to us.
What if my original part number is not 12663391?
This module is a direct replacement for several part numbers. Please check the compatibility list in the description (12692067, 12676230, etc.). As long as your original part number is on that list, this module will work correctly once programmed to your VIN.