Restore Peak Performance to Your GM Truck or SUV
Is your 2015-2016 GMC Yukon, Tahoe, or Silverado plagued by frustrating issues like a persistent check engine light, sudden stalling, rough idling, or a complete no-start condition? These are classic signs of a failing Engine Control Module (ECM), the computer that serves as your vehicle’s brain. When it malfunctions, it can throw your engine’s performance, fuel economy, and transmission shifting into chaos. I’ve seen it countless times in my 20+ years of diagnostics: a perfectly good engine held back by a faulty computer. This isn’t just an annoyance; it’s a reliability issue that can leave you stranded.
A Technician’s Notebook: The Ghost in the Machine
A few months back, a 2016 Sierra 1500 was towed into my bay. The owner was at his wit’s end. He’d been chasing an intermittent stalling problem for weeks. The truck would run fine for days, then die at a stoplight without warning. No consistent codes were stored, just a random U0100 (Lost Communication with ECM) every now and then. We checked grounds, wiring harnesses, and power feeds—all solid. On a hunch, I put the original ECM on my bench and applied a little heat from a heat gun to simulate under-hood temperatures. Sure enough, the processor started failing. A new, properly programmed ECM fixed it instantly. It’s a reminder that these complex electronics can fail in ways that defy simple code-pulling.
Why Choose Our Pre-Programmed ECM?
This isn’t just a replacement part; it’s a complete solution. We take a genuine GM Engine Control Module and flash it with the latest, most stable software release from General Motors, specifically matched to your vehicle using its unique VIN. This eliminates the most difficult part of the repair. You get a module that is ready to install right out of the box, saving you from a costly trip to the dealership for programming and the need for expensive diagnostic scan tools. This is the most direct path to solving your vehicle’s electronic woes and restoring the smooth, reliable operation you depend on.
Is Your Vehicle Showing These Telltale Signs?
A failing ECM can manifest in numerous ways. If you’re experiencing any of the following, your engine computer is the likely culprit:
- ✔ Unexplained Check Engine Light (CEL) activation
- ✔ Stored diagnostic trouble codes (DTCs) like P0601, P0606, or U0100
- ✔ Vehicle refuses to start or has intermittent starting issues
- ✔ Noticeable drop in fuel efficiency
- ✔ Rough or erratic engine idling
- ✔ Harsh or incorrect transmission shifting
- ✔ Engine stalling or hesitation during acceleration
Your Straightforward Installation Guide
Replacing the ECM on most of these GM trucks and SUVs is a job a confident DIYer can handle in under an hour. The module is typically located in the front left (driver’s side) of the engine compartment.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait a few minutes for the systems to discharge.
- Locate the ECM: Find the Engine Control Module. It’s a silver metal box with several large electrical connectors.
- Disconnect Wiring: Carefully release the locking tabs on each electrical connector and pull them straight out from the module. Never force them.
- Remove the Old Module: Unbolt the mounting hardware holding the old ECM in place and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed ECM in the same location and secure it with the original hardware.
- Reconnect and Secure: Plug the wiring harnesses back into the new module until they click firmly into place. Reconnect your battery terminal.
- Final Step: In some cases, a security or anti-theft relearn procedure may be required, which can typically be done without special tools. Instructions are widely available online for your specific model.
Verified Fitment For a Wide Range of GM Vehicles
This module is a direct replacement for part number 12663391 and is compatible with a broad selection of GM cars, trucks, and SUVs. Please verify your vehicle is on this list. It is also a compatible replacement for part numbers: 12692067, 12676230, 12656993, 12662034, 12672537, 12673195, 12672963, and 12669318.
- ✔ Cadillac ATS: 2014-2016
- ✔ Cadillac CTS: 2014-2016
- ✔ Cadillac Escalade / ESV: 2015-2016
- ✔ Cadillac XTS: 2014-2016
- ✔ Chevrolet Camaro: 2016 (6.2L)
- ✔ Chevrolet Colorado: 2015-2016 (3.6L)
- ✔ Chevrolet Corvette: 2014-2016
- ✔ Chevrolet Silverado 1500: 2014-2016
- ✔ Chevrolet Suburban 1500: 2015-2016
- ✔ Chevrolet Tahoe: 2015-2016
- ✔ GMC Canyon: 2015-2016 (3.6L)
- ✔ GMC Sierra 1500 / Denali 1500: 2014-2016
- ✔ GMC Yukon / Yukon XL 1500: 2015-2016
Frequently Asked Questions
How does the programming process work?
It’s simple. After you complete your purchase, you will need to send us your vehicle’s 17-digit VIN (Vehicle Identification Number). We use this to download the latest official GM software for your exact vehicle configuration and flash it onto the module before shipping.
Is this a true plug-and-play part?
Yes, for over 95% of vehicles. Because it arrives pre-programmed to your VIN, you will not need a dealer to program it. In some rare cases, a simple key relearn or security relearn procedure is needed, which does not require special tools.
Will this fix my specific problem?
This module is the definitive solution for issues directly caused by a faulty ECM. While it resolves the most common symptoms like stalling and no-starts, we always recommend a proper diagnosis to ensure the ECM is the root cause and not a wiring or sensor issue.
What if I have a different part number on my old module?
This module, part number 12663391, supersedes and is a direct replacement for several older part numbers, including 12692067, 12676230, 12662034, and others listed in our fitment section. As long as your vehicle is on the list, this module will work perfectly.
Do I need to return my old ECM?
No core charge is required for this purchase. You can keep your old module, though we always recommend recycling old electronics responsibly.