Restore Peak Performance to Your GM Truck
Is your Silverado, Sierra, or other GM vehicle suddenly stalling, refusing to start, or showing a persistent Check Engine Light? As a technician with over two decades of experience under the hood, I’ve seen these exact symptoms hundreds of times. Often, the culprit is a failing Engine Control Module (ECM). This isn’t just an inconvenience; a faulty ECM can affect fuel economy, transmission shifting, and overall engine stability. This replacement Engine Control Module, part number 12674472, is the reliable, straightforward solution to get your truck running like new again.
We take the guesswork and dealership hassle out of the equation. Before we ship this module, we program it specifically to your vehicle using the VIN you provide. This ensures it has the latest, most stable software directly from GM, tailored to your truck’s exact specifications. This critical step saves you from needing a specialized—and expensive—programming session after installation. You get a part that is truly ready for the final installation steps in your vehicle.
Case Study: A Tricky Diagnosis
A customer brought in a 2017 Sierra 1500 with an intermittent no-start and random stalling. They had already replaced the battery and alternator, but the problem persisted. The dash was clean—no check engine light. My initial scan showed no hard codes, but live data revealed erratic voltage readings from several key sensors, all pointing back to the ECM. On these GM trucks, internal ECM circuit board failure, often from heat cycles and vibration, can cause these ghost-like issues long before a hard code like P0601 (Internal Control Module Memory Check Sum Error) appears. We installed a VIN-programmed ECM, performed the VTD relearn, and the truck has run flawlessly since. This part fixed a problem that other shops had missed.
Is Your Truck Showing These Symptoms?
- ✔ Engine stalling or misfiring unpredictably.
- ✔ Complete no-start condition where the engine cranks but won’t fire.
- ✔ Check Engine Light is on with codes related to module communication or internal errors (e.g., P0601, P0606, U0100).
- ✔ Noticeable drop in fuel efficiency.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Issues with other electronic systems that communicate with the ECM.
A Straightforward Guide to Installation
Installing your new 2016-2018 Silverado 1500 ECM is a manageable job for a DIYer with basic tools or a quick task for a professional mechanic. Follow these steps carefully.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electronic work.
- Locate the ECM: On most Silverado and Sierra models, the ECM is located in the engine compartment on the driver’s side, near the firewall or inner fender.
- Disconnect Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the module. Avoid pulling on the wires themselves.
- Remove the Module: Unbolt the old ECM from its mounting bracket.
- Install New ECM: Mount the new, pre-programmed ECM in place and securely tighten the bolts. Reconnect the wiring harnesses, ensuring they click firmly into place.
- Reconnect Battery: Re-attach 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 scan tool with GM software (like Tis2web/Techline Connect). Other relearns, such as for the crankshaft position sensor, may also be necessary depending on your specific vehicle.
IMPORTANT NOTICE: The buyer is responsible for performing all necessary post-installation procedures, including the VTD relearn, crankshaft variation relearn, and any others required by the vehicle. We supply the correctly programmed part; the final vehicle-specific integration is the responsibility of the installer.
Verified Vehicle Compatibility
This module is a direct replacement for part number 12674472 and interchanges with part numbers 12692068, 12704476, 12686382, 12674052, and 12678815. It is confirmed to fit the following vehicles:
- 2016-2018 Chevrolet Silverado 1500
- 2016-2018 GMC Sierra 1500 / Sierra Denali 1500
- 2017 Cadillac Escalade / Escalade ESV
- 2017 Chevrolet Suburban 1500
- 2017 Chevrolet Tahoe
- 2017 GMC Yukon / Yukon XL 1500
- 2017 Cadillac ATS (3.6L LF4)
- 2017 Cadillac CTS (6.2L Supercharged / 3.6L LF3 Twin Turbo)
- 2017 Cadillac XTS (3.6L LF3)
- 2017 Chevrolet Corvette
Please verify your original part number or consult with us if you are unsure about fitment. Providing your VIN at checkout is required for programming and ensures compatibility.
Frequently Asked Questions
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to load the exact, correct GM-certified software for your truck’s specific engine, transmission, and emissions equipment. This ensures proper function and avoids compatibility issues.
What is a Vehicle Theft Deterrent (VTD) relearn?
The VTD system, also known as Passlock or Passkey, prevents theft by ensuring the ECM and other security modules recognize each other. When you install a new ECM, this link is broken. The relearn procedure re-establishes that secure connection, allowing the vehicle to start. It requires a professional scan tool with GM software access.
Can I do the VTD relearn myself?
Typically, no. The VTD relearn requires access to GM’s Tis2web or Techline Connect software, which is usually only available to professional repair shops or advanced DIYers with a subscription and a compatible J2534 interface tool.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of your original ECM (common codes P0601-P0606), then this part will resolve the issue. However, you must ensure the root cause of the problem isn’t a faulty sensor or wiring, as a new ECM will not fix external problems.
Is this part difficult to install?
The physical replacement of the module is very simple—usually just a few bolts and electrical connectors. The most complex part is the electronic relearn procedure that must be performed after installation.