Restore Peak Performance to Your GM Vehicle
Is your Cadillac, Chevy, or GMC truck plagued by a persistent check engine light, erratic engine behavior, or a frustrating no-start condition? You’re not alone. The Engine Control Module (ECM) is the brain of your vehicle’s powertrain, and when it fails, it can cause a cascade of confusing and costly problems. This direct-fit ECM, part number 12663391, is the reliable, straightforward solution to get your vehicle running smoothly again. Forget expensive dealership visits and complex programming tools. We handle the hard part for you.
Upon purchase, simply provide us with your vehicle’s 17-digit VIN. Our technicians will then program this module with the very latest GM-certified software specific to your car or truck. This ensures perfect communication between the ECM and all other vehicle systems, restoring factory performance, fuel efficiency, and emissions control. This isn’t just a replacement part; it’s a new lease on life for your vehicle’s most critical component.
Case Study: A Tricky Diagnosis
I once had a 2015 Silverado 1500 in my bay that was driving the owner crazy. It would randomly stall at stoplights, but never threw a consistent code. We checked fuel pressure, sensors, and wiring harnesses for days. Finally, on a hunch, we monitored the live data stream from the ECM and noticed the processor would momentarily drop offline right before a stall. It was a classic case of internal ECM failure that standard diagnostics couldn’t pinpoint. We installed a VIN-programmed module just like this one, and the truck has run flawlessly for the owner ever since. Sometimes, the problem really is the brain itself.
Is Your Vehicle Showing These ECM Failure Signs?
A failing ECM can manifest in many ways. If you’re experiencing any of the following, a faulty module could be the culprit. Proper diagnosis is always recommended, but these are strong indicators:
- ✔ Persistent Check Engine Light (CEL)
- ✔ Engine stalling, stumbling, or misfiring
- ✔ No-start or hard-starting conditions
- ✔ Noticeable decrease in fuel economy
- ✔ Poor or erratic automatic transmission shifting
- ✔ Loss of communication with the scan tool
- ✔ Diagnostic Trouble Codes (DTCs) such as P0601, P0606, or U0100
A Straightforward Guide to Your 2014-2016 ATS ECM Installation
Replacing your ECM is easier than you might think, especially since we handle the programming. While specific locations vary, this guide covers the general process.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection.
- Locate the ECM: On most listed vehicles, the ECM is found in the engine compartment—often on the driver’s side front, on the firewall, or near the cowl. Check your specific model’s service information if you’re unsure.
- Disconnect the Connectors: Carefully release the locking tabs on the electrical wiring harnesses and pull them straight out from the module. Never force them. Inspect the connectors for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the hardware, as you will need it to install the new unit.
- Install the New ECM: Mount your new, pre-programmed ECM onto the bracket and secure it with the original hardware.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: Many GM vehicles require a simple security relearn procedure after ECM replacement. This usually involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your owner’s manual or a reliable online resource for the specific procedure for your vehicle.
Verified Vehicle Compatibility
This module is a direct replacement for part number 12663391 and is also compatible with the following part numbers: 12692067, 12676230, 12656993, 12662034, 12672537, 12673195, 12672963, and 12669318. It fits a wide range of GM models, including but not limited to:
- ✔ Cadillac ATS (2014-2016)
- ✔ Cadillac CTS (2014-2016)
- ✔ Cadillac Escalade / ESV (2015-2016)
- ✔ Cadillac XTS (2014-2016)
- ✔ Chevrolet Camaro (2016)
- ✔ Chevrolet Colorado (2015-2016)
- ✔ Chevrolet Corvette (2014-2016)
- ✔ Chevrolet Silverado 1500 (2014-2016)
- ✔ Chevrolet Suburban 1500 (2015-2016)
- ✔ Chevrolet Tahoe (2015-2016)
- ✔ GMC Canyon (2015-2016)
- ✔ GMC Sierra 1500 / Denali 1500 (2014-2016)
- ✔ GMC Yukon / Yukon XL 1500 (2015-2016)
Frequently Asked Questions
Frequently Asked Questions
What information do you need from me to program the module?
After you complete your purchase, we will need the 17-digit Vehicle Identification Number (VIN) from your vehicle. This allows us to load the exact, correct software for your specific model, engine, and options.
Is this module truly plug-and-play?
Because we program it to your VIN, it eliminates the need for expensive dealer tools. However, most GM vehicles will require a simple security relearn procedure that you can do yourself in about 15 minutes with just the ignition key. This pairs the new ECM to your vehicle’s anti-theft system.
Will this fix my check engine light?
If the check engine light and performance issues are caused by a faulty ECM, then yes, this part is the correct fix. It is crucial to have your vehicle properly diagnosed to confirm the ECM is the point of failure before ordering.
Does this come with the newest software available?
Absolutely. We program every module with the latest stable software release from General Motors. This ensures all known bugs are fixed and your vehicle operates as efficiently as possible.
My original part number is different. Will this still work?
Yes. This ECM is a direct replacement for several part numbers, including 12692067, 12676230, and others listed in the compatibility section. As long as your vehicle is on the fitment list, we can program this module to work perfectly.