Is Your GM Vehicle Suffering from Mysterious Electrical Gremlins?
If you’re dealing with frustrating issues like a persistent check engine light, erratic engine performance, stalling, or a complete no-start condition, the culprit is often the Engine Control Module (ECM). As the central computer of your vehicle, a failing ECM can cause a cascade of problems that are difficult to diagnose. I’ve seen it hundreds of times in my shop: a beautiful Cadillac, a powerful Sierra, or a reliable Tahoe is sidelined by what seems like a major failure, but it all traces back to this single component.
This isn’t just a replacement part; it’s a direct solution. We take the guesswork and high dealership costs out of the equation. This genuine GM Engine Control Module, compatible with part number 12674052 and others, arrives at your door pre-programmed with the latest GM software updates specifically for your vehicle. All we need is your Vehicle Identification Number (VIN) at checkout to ensure a perfect software match, restoring your vehicle’s factory-specified performance and efficiency.
Case Study: The Intermittent Sierra
A customer brought in a 2017 Sierra 1500 that would randomly refuse to start. No rhyme or reason. It would be fine for a week, then dead in the driveway. The battery was good, the starter was fine, but the scan tool showed intermittent communication loss with the ECM (U0100 codes). After confirming the wiring harness was secure and free of corrosion, we pinpointed the ECM itself. Internal circuit board failure is common after years of heat cycles. We installed a VIN-programmed module just like this one, performed the quick theft-deterrent relearn, and the truck has been starting reliably ever since. It’s a fix that saves hours of diagnostic headaches.
Common Signs Your GM’s ECM is Failing
If you’re experiencing any of the following, a faulty ECM could be the root cause. A failing module often throws specific Diagnostic Trouble Codes (DTCs) that a standard OBD-II scanner can read.
- ✔ Vehicle will not start or has trouble starting.
- ✔ Check Engine Light is illuminated with codes like P0601, P0606, or other internal processor faults.
- ✔ Loss of communication with the module (U-codes).
- ✔ Poor fuel economy and engine performance, including misfires or hesitation.
- ✔ Transmission shifting issues or failure to go into gear.
- ✔ Stalling for no apparent reason while driving.
A Straightforward Guide to Your ECM Installation
Replacing the ECM is a manageable job for a confident DIYer or any professional technician. The most critical part is the post-installation procedure.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
- Locate the ECM: On most listed models, the ECM is found in the engine compartment (typically on the driver’s side) or under the cowl. Consult a service manual for your specific vehicle’s location.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that need to be released. Once disconnected, unbolt the old module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed ECM into place. Reconnect the wiring harnesses, ensuring they click securely into position.
- Reconnect Battery: Reattach the negative battery terminal.
- CRITICAL – Perform Relearns: The vehicle will likely not start until a Security/Theft Deterrent Relearn is completed using a compatible scan tool with access to GM’s TIS2Web or Techline Connect system. This syncs the new ECM with your vehicle’s anti-theft system. Other procedures like a Crankshaft Variation Relearn may also be necessary. This step is the responsibility of the installer.
Verified Compatibility for Your GM Vehicle
This module is a direct-fit replacement for the following vehicles and part numbers. Please verify your part number or contact us with your VIN to confirm fitment.
Replaces Part Numbers: 12692068, 12704476, 12686382, 12674052, 12674472, 12678815
- Cadillac ATS: 2017 (3.6L, VIN Y, opt LF4)
- Cadillac CTS: 2017 (6.2L Supercharged; 3.6L Twin Turbo, VIN 8, opt LF3)
- Cadillac Escalade / ESV: 2017
- Cadillac XTS: 2017 (3.6L, VIN 8, opt LF3)
- Chevrolet Corvette: 2017
- Chevrolet Silverado 1500: 2016-2018
- Chevrolet Suburban 1500: 2017
- Chevrolet Tahoe: 2017
- GMC Sierra 1500 / Denali 1500: 2016-2018
- GMC Yukon / Yukon XL 1500: 2017
Where do I provide my VIN?
Please enter your 17-digit VIN in the notes section during checkout or send it to us via email after your purchase. We cannot program and ship the module without it.
Will my car start immediately after installation?
No. In most cases, a Vehicle Theft Deterrent System relearn is required. This procedure syncs the new ECM to your vehicle’s ignition keys and security system. Without it, the vehicle’s security will prevent it from starting.
What tools are needed for the relearn procedure?
The security relearn must be performed with a professional-grade scan tool that has access to the official GM programming software, such as TIS2Web or Techline Connect. This is standard for most automotive repair shops.
Do I need to do any other relearns?
Possibly. Depending on your vehicle, other procedures like a Crankshaft Position Variation Relearn or injector flow rate programming may be needed to ensure optimal performance. This is the responsibility of the installer.
My original part number isn’t 12674052, but it’s on the list. Will this work?
Yes. The part numbers listed (e.g., 12692068, 12674472) are all interchangeable. As long as your original module’s part number is on our list, this unit will function correctly once programmed to your VIN.