Restore Peak Performance to Your GM Truck or SUV
Is your Silverado, Sierra, or Tahoe running rough, throwing confusing check engine codes, or refusing to start? The Engine Control Module (ECM), often called the engine computer, is the brain of your vehicle’s operation. When it fails, it can cause a cascade of frustrating and difficult-to-diagnose problems. This genuine GM Engine Control Module, part number 12704476, is the definitive solution to restore your vehicle’s factory performance, fuel efficiency, and reliability.
Unlike generic modules from a parts store, this ECM is not a one-size-fits-all solution. We provide a crucial service: programming the module specifically to your vehicle’s Vehicle Identification Number (VIN) before it ships. This ensures that all software and calibrations are a perfect match for your truck’s specific engine, transmission, and emissions equipment. We load the latest, most stable software updates directly from GM, which can often resolve issues that were present even when the truck was new.
From the Diagnostic Bay
We had a 2017 Sierra 1500 come in with the strangest set of symptoms. The owner complained of intermittent stalling at stoplights, hard shifting from 2nd to 3rd gear, and a check engine light that would come and go with a random misfire code. We checked everything – spark plugs, coils, fuel injectors, even the throttle body. Everything tested fine. After hours of chasing our tails, we scoped the ECM’s outputs and found erratic signals to the transmission solenoids and fuel injector drivers. A faulty ECM was the culprit. We installed a VIN-programmed module, performed the necessary relearn procedures, and the truck ran like it just rolled off the showroom floor. It’s a perfect example of how a failing computer can mimic a dozen other mechanical problems.
Is Your Silverado Showing These Symptoms?
A failing engine computer can manifest in numerous ways. If you’re experiencing any of the following, a faulty ECM could be the root cause. This 2016-2018 Silverado ECM is designed to correct these exact issues:
- ✔ Check Engine Light (CEL) is on with various communication or sensor codes (e.g., U-codes).
- ✔ Vehicle has a no-start or hard-start condition.
- ✔ Noticeable decrease in fuel economy.
- ✔ Engine stalling, sputtering, or misfiring unexpectedly.
- ✔ Rough or erratic automatic transmission shifting.
- ✔ Loss of power and poor acceleration.
- ✔ Issues with other electronic modules, like the instrument cluster or anti-lock brakes.
The Importance of VIN Programming and Relearn Procedures
Modern vehicles have complex, interconnected systems. Simply swapping an ECM will not work. Our process ensures the first step is done for you: we flash the module with your vehicle’s VIN and the correct GM-certified software. However, for the module to communicate with the rest of your vehicle, a few final steps are required upon installation. This is a standard procedure for this type of repair.
NOTICE: The buyer is responsible for performing post-installation procedures. This typically includes:
- Vehicle Theft Deterrent System (VTDS) Relearn: This is the most critical step. It syncs the new ECM with your vehicle’s anti-theft system and ignition keys. Without this, the vehicle will not start. This procedure requires a professional scan tool with GM programming capabilities, such as Tis2web or Techline Connect.
- Crankshaft Variation Relearn (CASE Relearn): This calibrates the ECM to the precise position of the crankshaft, ensuring accurate ignition timing and misfire detection.
- Other Setups: Depending on your vehicle’s options, other minor relearns or setups, like for fuel injectors, may be necessary.
We provide the correctly programmed 2016-2018 Silverado ECM; the final integration into your specific vehicle must be completed by the installer.
Guaranteed Fitment for Your GM Vehicle
This module is a direct replacement for part number 12704476 and is also compatible with part numbers 12692068, 12686382, 12674052, 12674472, and 12678815. It fits a wide range of GM trucks, SUVs, and cars. Please verify your part number and check the fitment list below:
- Cadillac Escalade / ESV: 2017
- Cadillac XTS: 2017 (3.6L Twin Turbo, VIN 8)
- Cadillac CTS: 2017 (6.2L Supercharged or 3.6L Twin Turbo)
- Cadillac ATS: 2017 (3.6L Twin Turbo, VIN Y)
- Chevrolet Corvette: 2017
- Chevrolet Tahoe: 2017
- Chevrolet Suburban 1500: 2017
- Chevrolet Silverado 1500 Pickup: 2016 (ID 12674472), 2017, 2018 (ID 12686382)
- GMC Yukon / Yukon XL 1500: 2017
- GMC Sierra 1500 Pickup: 2016 (ID 12674472), 2017, 2018 (ID 12686382)
- GMC Sierra Denali 1500: 2017, 2018 (ID 12686382)
Frequently Asked Questions
Why do I need to provide my VIN?
Your vehicle’s VIN is essential for us to load the exact software and calibrations specified by GM for your truck’s engine, transmission, and options. This ensures compatibility and proper function, saving you from potential performance issues.
Will my truck start immediately after I install this ECM?
No, it will not. After installation, a Vehicle Theft Deterrent System (VTDS) relearn must be performed using a GM-compatible diagnostic tool. This security procedure syncs the new ECM to your vehicle’s keys and is a mandatory step.
Can I perform the theft relearn myself?
The relearn procedure requires access to GM’s Tis2web or Techline Connect software, which is typically only available to professional repair shops or dealerships. We strongly recommend having a qualified technician with the proper equipment perform the installation and final setup.
Is this a plug-and-play part?
While it is a direct physical replacement, it is not ‘plug-and-play’ electronically. Our VIN programming is the first critical step, but the final on-vehicle security relearn and other calibrations are required for the part to function correctly.
What happens if I don’t do the crankshaft variation relearn?
Skipping the crankshaft variation (CASE) relearn can result in an illuminated check engine light and inaccurate misfire detection by the ECM. This can lead to incorrect diagnostics down the road, so it is a highly recommended procedure.