Restore Peak Performance to Your GM Vehicle
Is your Cadillac, Chevrolet, or GMC suffering from baffling electrical issues, a persistent check engine light, or a no-start condition? As the central computer of your vehicle, a failing Engine Control Module (ECM) can cause a cascade of problems that are often misdiagnosed. I’ve seen it countless times in my 20+ years in the shop: perfectly good sensors and components get replaced, but the root cause—a faulty ECM—remains. This genuine GM ECM, part number 12674472, is the definitive solution to restore your vehicle’s drivability and reliability.
We take the biggest headache out of the replacement process. Unlike buying a blank module from a dealer, this unit arrives at your door pre-programmed with the latest official GM software, tailored specifically to your vehicle’s Vehicle Identification Number (VIN). This ensures all factory calibrations for your engine and transmission are correct from the moment of installation, saving you a costly trip to the dealership for initial programming. This is the most efficient way to get your vehicle back to factory-spec operation.
From the Diagnostic Bay: The Ghost in the Machine
A customer brought in a 2017 Sierra 1500 that had other shops stumped. It would randomly stall at idle and had intermittent communication loss codes (U0100) that would come and go. They had already replaced the battery and alternator. After hooking up my scan tool and monitoring live data, I noticed the 5-volt reference signal from the ECM would occasionally dip, causing multiple sensors to report erratically just before a stall. This wasn’t a wiring issue; it was the ECM’s internal voltage regulator failing under load. We installed a VIN-programmed module like this one, performed the quick crankshaft variation relearn, and the truck ran flawlessly. It’s a classic case where the symptoms point everywhere, but the true culprit is the vehicle’s brain.
Is Your Vehicle Showing These Common ECM Failure Signs?
A failing ECM can manifest in various ways. If you’re experiencing any of the following, this module is likely the solution you need:
- ✔ Check Engine Light is on with codes like P0601, P0606 (Internal Control Module Processor Error).
- ✔ Vehicle will not start or is very difficult to start.
- ✔ Stalling, hesitation, or rough idling for no apparent reason.
- ✔ Noticeable decrease in fuel economy.
- ✔ Transmission shifting erratically or not shifting at all.
- ✔ Loss of communication with other vehicle modules (U-codes).
A Straightforward Guide to Replacing Your ECM
Replacing the ECM is a manageable job for a confident DIYer or a quick task for any professional technician. Our pre-programming service handles the most complex step for you. Here’s a general guide:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the ECM: On most of these GM trucks and SUVs, the ECM is located in the engine compartment, typically on the driver’s side. On cars like the Corvette or XTS, the location may vary (e.g., cowl area, under the dash). Consult a service manual for your specific model.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that need to be released. Once disconnected, unbolt the module from its mounting bracket and remove it.
- Install the New Module: Bolt the new, pre-programmed ECM into place. Firmly reconnect the wiring harness connectors, ensuring they click and lock securely.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Relearn Procedures: Attempt to start the vehicle. If it does not start, you must perform the Vehicle Theft Deterrent (VTD) relearn using a compatible GM diagnostic tool (like TIS2Web/Techline Connect). Other procedures like a crankshaft variation relearn may also be required to clear certain codes and ensure optimal performance. This final step is the responsibility of the installer.
Verified Fitment for Your General Motors Vehicle
This module is a direct replacement for part numbers 12692068, 12704476, 12686382, 12674052, 12674472, and 12678815. It is confirmed to fit the following vehicles:
- Cadillac ATS (2017): 3.6L (VIN Y, LF4)
- Cadillac CTS (2017): 6.2L Supercharged & 3.6L Twin Turbo (VIN 8, LF3)
- Cadillac Escalade / ESV (2017)
- Cadillac XTS (2017): 3.6L (VIN 8, 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)
Important: After purchase, please provide your VIN to ensure we load the correct, most current software for your specific vehicle configuration.
Frequently Asked Questions
What does ‘programmed to my VIN’ mean?
It means we load the specific software and calibration files from GM that match your vehicle’s exact factory options, including engine, transmission, and emissions equipment. This makes installation much simpler than starting with a blank module.
Do I need to do anything after I install it?
Yes. In many cases, you must perform a Vehicle Theft Deterrent (VTD) relearn for the vehicle to start. This security procedure syncs the new ECM to your vehicle’s key and anti-theft system. Other relearns, like for the crankshaft position sensor, may also be needed. These procedures require a compatible professional scan tool with GM software.
What happens if I don’t provide my VIN?
We cannot ship the module without your VIN. The programming is essential for the part to function correctly in your vehicle. Please send us your 17-digit VIN through messenger after checkout to avoid delays.
Is this a guaranteed fix for my vehicle’s problems?
This ECM will fix problems directly caused by a faulty ECM. While the symptoms listed are common for ECM failure, we always recommend a proper diagnosis by a qualified technician to confirm the ECM is the point of failure before ordering.
Will this work for a different year or model not listed?
No. This module is specifically for the makes, models, and years listed in the compatibility chart. Using it in an unsupported vehicle will not work and may cause damage. Please verify your part number and vehicle fitment before ordering.