Is your Cadillac XTS, Silverado, Sierra, or other GM vehicle suffering from perplexing engine issues? A faulty Engine Control Module (ECM) is often the culprit behind problems like a persistent check engine light, poor fuel economy, rough idling, or even a no-start condition. The ECM is the brain of your engine, and when it fails, the entire vehicle’s performance suffers. This replacement Engine Control Module, part number 12663391, is the definitive solution to restore your vehicle’s factory performance and reliability.
We take the guesswork and hassle out of the repair process. Unlike a generic module from a parts store, this ECM comes fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). We load the latest, most stable software updates directly from GM, ensuring optimal communication between all your vehicle’s systems. This VIN-specific programming is critical for modern vehicles, as it ensures proper function of the engine, transmission, anti-lock brakes, and security systems. By providing us with your VIN upon purchase, you receive a module that is ready for installation right out of the box, saving you a costly trip to the dealership for programming.
We had a 2015 Silverado 1500 come into the shop with a strange, intermittent stalling issue that no one could figure out. The owner had replaced the fuel pump and multiple sensors, but the truck would still die randomly at stoplights. After hours of diagnostics, we traced the issue to a failing ECM that was intermittently dropping communication with the fuel injector drivers. Instead of a complex and expensive dealer repair, we sourced a VIN-programmed module just like this one. The installation was straightforward, and after a quick security relearn procedure, the truck ran perfectly. The customer was thrilled to have a reliable vehicle again without the massive dealership bill.
Common Symptoms of a Failing Engine Control Module
If you’re experiencing any of the following issues, a faulty ECM could be the root cause. Replacing it with a correctly programmed unit is the most effective way to solve these complex electronic problems.
- ✔ Persistent and illuminated Check Engine Light (CEL)
- ✔ Engine stalling or misfiring for no apparent reason
- ✔ Noticeable decrease in fuel efficiency
- ✔ Vehicle fails to start or has difficulty starting
- ✔ Rough or erratic idling
- ✔ Poor acceleration and overall engine performance
- ✔ Automatic transmission shifting problems
- ✔ Communication errors with diagnostic scan tools
Why Choose Our 2014-2016 XTS ECM Solution?
This isn’t just a replacement part; it’s a complete, hassle-free solution. The key is our professional programming service. A new ECM installed without the correct software for your specific vehicle simply will not work. Our process ensures that the module you receive is a perfect electronic match for your car or truck. This unit is a direct-fit replacement for a wide range of popular GM vehicles, including the Cadillac XTS, ATS, CTS, Escalade, Chevrolet Silverado, Tahoe, Suburban, Corvette, Camaro, and GMC Sierra, Yukon, and Canyon. It is compatible with multiple original part numbers, including 12692067, 12676230, 12656993, 12662034, and more, making it a versatile and reliable choice for your repair.
The installation process is designed to be as simple as possible. Once you receive the programmed module, you’ll disconnect the battery, locate and swap the old ECM with the new one, and reconnect the battery. For most GM vehicles of this era, you will need to perform a simple security relearn procedure, which can typically be done in your driveway without any special tools. This procedure pairs the new ECM to your vehicle’s existing keys and anti-theft system, a necessary final step for the vehicle to start and run. By choosing our pre-programmed module, you bypass the most complicated and expensive part of the job—dealership-level computer flashing.
Frequently Asked Questions
What is an ECM and what does it do?
The Engine Control Module (ECM) is your vehicle’s main computer. It controls critical engine functions like fuel injection timing, spark timing, variable valve timing, and emissions systems to ensure optimal performance, fuel economy, and low emissions.
Is this part truly plug-and-play?
Because we program the module to your VIN, it is nearly plug-and-play. After physical installation, you will likely need to perform a simple security relearn procedure, which takes about 10-15 minutes and involves turning the key in the ignition. Instructions are readily available online for your specific model.
How do I provide my VIN number?
After you complete your purchase, simply send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot program and ship your module until we receive this information. You can find your VIN on your vehicle’s registration, insurance card, or on the driver’s side dashboard viewable through the windshield.
Will this fix my check engine light?
If the check engine light and associated diagnostic trouble codes (DTCs) are caused by a faulty ECM, then yes, this will resolve the issue. We recommend having a professional diagnosis to confirm the ECM is the point of failure before ordering.
Does this part fit vehicles other than the Cadillac XTS?
Yes. This ECM is compatible with a wide variety of 2014-2016 GM cars and trucks, including the Silverado 1500, Sierra 1500, Corvette, Camaro, Tahoe, Yukon, and more. Please check the detailed fitment list in the description to confirm it matches your specific vehicle.