Restore Peak Performance to Your GM Vehicle
Is your Cadillac, Chevrolet, or GMC 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, stalling, or a no-start condition. The ECM is the brain of your vehicle’s engine, and when it fails, it can cause a cascade of frustrating and difficult-to-diagnose symptoms. This genuine GM Engine Control Module, part number 12663391, is the definitive solution to restore your vehicle’s factory performance, drivability, and reliability.
We take the guesswork and hassle out of the replacement process. Unlike a generic module from a parts store or a salvage yard, this ECM comes professionally programmed specifically for your vehicle. Simply provide us with your Vehicle Identification Number (VIN) during checkout, and our technicians will flash the module with the latest, most stable software updates directly from General Motors. This ensures seamless communication with all other vehicle systems and guarantees a true plug-and-play installation, eliminating the need for an expensive trip to the dealership for programming.
From the Diagnostic Bay
We had a 2015 Silverado 1500 in the shop that was driving the owner crazy. It would randomly stall at stoplights and had an intermittent P0606 (ECM Processor Fault) code that would come and go. We checked all the wiring, grounds, and power feeds to the ECM—everything was perfect. The owner had already replaced the throttle body and MAF sensor with no luck. On a hunch, we swapped in a known-good, VIN-programmed ECM. The truck immediately ran flawlessly. The internal processor on the original module was failing intermittently under specific load conditions. This case highlights how a faulty ECM can mimic other component failures, making a correctly programmed replacement the only true fix.
Is Your GM Vehicle Showing These Symptoms?
A failing ECM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your engine’s computer may need replacement:
- ✔ Persistent Check Engine Light (CEL) with various codes, especially communication or processor-related faults.
- ✔ Unexplained drops in fuel efficiency.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Rough or erratic idling.
- ✔ Noticeable loss of engine power.
- ✔ Automatic transmission shifting issues.
- ✔ Failure to pass emissions testing.
The Importance of a VIN-Programmed 2014-2016 CTS ECM
Modern vehicles are complex networks of computers. The ECM needs to know the exact specifications of your vehicle—engine size, transmission type, emissions equipment, and even tire size—to function correctly. Our VIN-programming service ensures this 2014-2016 CTS ECM is a perfect digital match for your car or truck. This critical step prevents compatibility issues, ensures all features work as intended, and provides your vehicle with the most recent drivability and performance enhancements from GM. Don’t settle for a blank module that requires additional costs and specialized tools to set up. Get the solution that works right out of the box.
This module is a direct replacement for a wide range of popular GM vehicles, including the Cadillac ATS, CTS, Escalade, and XTS; the Chevrolet Corvette, Camaro, Silverado, Suburban, and Tahoe; and the GMC Sierra, Yukon, and Canyon. Please verify your part number or consult the detailed fitment list to confirm compatibility. This unit is an interchangeable replacement for part numbers: 12692067, 12676230, 12656993, 12662034, 12672537, 12673195, 12672963, and 12669318.
Frequently Asked Questions
Why do I need to provide my VIN?
Your Vehicle Identification Number (VIN) contains critical information about your vehicle’s specific build, including engine, transmission, and emissions options. We use the VIN to load the exact GM-certified software onto the ECM, ensuring it works perfectly with your vehicle’s systems without any additional programming required.
Is this part truly plug-and-play?
Yes. Because we program the module to your VIN before shipping, it is ready for installation right out of the box. In most cases, you will not need to perform any additional security relearn procedures or programming. Simply install the module, connect the battery, and start your vehicle.
How do I know if my ECM is the problem?
Common signs of a failing ECM include a check engine light with codes like P0601-P0606, stalling, no-start conditions, poor fuel economy, and erratic engine behavior. It’s always best to have a qualified technician perform a full diagnostic, but these symptoms are strong indicators of a faulty module.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of your old ECM, this replacement module will resolve the issue. However, if the light is on due to a faulty sensor or another component, you will still need to address that separate problem.
Does this module fit vehicles other than the 2014-2016 Cadillac CTS?
Absolutely. This ECM is compatible with a wide array of GM cars and trucks from 2014-2016, including the Silverado, Sierra, Corvette, Camaro, Tahoe, and many others. Please refer to the detailed compatibility list on this page to confirm it fits your specific model.