Restore Peak Performance to Your GM Vehicle
Is your Cadillac, Chevy, or GMC suffering from frustrating and unpredictable issues like stalling, a persistent check engine light, or a complete no-start condition? You’re not alone. The Engine Control Module (ECM), the literal brain of your vehicle’s engine, is a common point of failure. When it falters, it can cause a cascade of problems that leave even seasoned mechanics scratching their heads. This replacement 2017 ATS Engine Module is the definitive solution, arriving at your door pre-programmed with the latest GM factory software specific to your vehicle’s VIN.
We take the guesswork and high dealership costs out of the equation. Simply provide us with your VIN during checkout, and our experts will flash this module, ensuring it’s a perfect match for your vehicle’s systems. This critical step saves you hundreds in programming fees and eliminates the need for specialized, expensive equipment for the initial software load.
Case Study: A Tricky Diagnosis
A 2017 Silverado 1500 came into my shop with a complaint that baffled the owner: intermittent stalling at stoplights and a random loss of power on the highway. No consistent codes were stored, just a history of network communication faults (U-codes). We checked grounds, wiring, and sensors for days. Finally, during a test drive with a scope attached, we caught the 5-volt reference signal from the ECM dropping out for a split second. That was it. The internal processor was failing under load. We replaced the ECM with a VIN-programmed unit like this one, performed a quick crankshaft variation relearn, and the truck has run flawlessly ever since. These symptoms are common across the entire platform, from the Corvette to the Escalade.
Is Your Vehicle Showing These Telltale Signs?
A failing ECM can manifest in numerous ways. If you’re experiencing any of the following, this module is likely the solution you need:
- ✔ Complete no-start or cranks-but-won’t-start condition
- ✔ Check Engine Light (CEL) with internal processor codes (e.g., P0601, P0606)
- ✔ Communication errors with scan tools (e.g., U0100)
- ✔ Poor or erratic automatic transmission shifting
- ✔ Significant drop in fuel economy
- ✔ Intermittent stalling or engine hesitation
- ✔ Misfires on multiple cylinders without a clear cause
A Straightforward Guide to Installation
Replacing the ECM is a manageable job for a DIY enthusiast or a quick task for any professional technician. While the module comes programmed, a final security handshake with your vehicle is required.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the Module: On most of these vehicles, the ECM is found in the engine compartment, typically on the driver’s side. Consult a service manual for your specific model’s exact location.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that must be released. Then, unbolt the old module from its mounting bracket.
- Install the New Module: Bolt the new ECM into place and securely reconnect the wiring harnesses. Ensure they click into place.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Security Relearn: This is a critical final step. If the vehicle does not start, you or your mechanic must perform a Vehicle Theft Deterrent (VTD) relearn using a GM-compatible scan tool with access to Tis2web or Techline Connect. This syncs the new ECM to your vehicle’s anti-theft system. Other procedures like a crankshaft variation relearn may also be necessary.
Verified Vehicle Compatibility
This module, part number 12678815, is a direct replacement for several original part numbers, including 12692068, 12704476, 12686382, 12674052, and 12674472. It is guaranteed to fit the following models:
- 2017 Cadillac ATS (3.6L, VIN Y, opt LF4)
- 2017 Cadillac CTS (6.2L Supercharged or 3.6L Twin Turbo)
- 2017 Cadillac Escalade / Escalade ESV
- 2017 Cadillac XTS (3.6L, VIN 8, opt LF3)
- 2017 Chevrolet Corvette
- 2016-2018 Chevrolet Silverado 1500 Pickup
- 2017 Chevrolet Suburban 1500
- 2017 Chevrolet Tahoe
- 2016-2018 GMC Sierra 1500 Pickup
- 2017-2018 GMC Sierra Denali 1500
- 2017 GMC Yukon / Yukon XL 1500
Frequently Asked Questions About This ECM
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, you will receive instructions to reply with your 17-digit Vehicle Identification Number (VIN). We cannot ship the module until we receive this information.
What is a security relearn and is it difficult?
The security relearn is a simple procedure that syncs the new ECM to your vehicle’s existing keys and anti-theft system. It requires a professional scan tool with access to GM’s software (Tis2web/Techline Connect). Most independent repair shops can perform this procedure in minutes. It is the buyer’s responsibility to have this step completed.
Will this fix my specific problem?
This 2017 ATS Engine Module is a direct solution for failures within the ECM itself. While it corrects a wide range of issues, it’s essential to ensure your vehicle has been properly diagnosed. This part will not fix problems related to failed sensors, bad wiring, or other mechanical issues.
Does my original part number have to match 12678815 exactly?
No. This module is a direct replacement for all part numbers listed in the description, including 12692068, 12704476, 12686382, 12674052, and 12674472. As long as your vehicle is on the compatibility list, this part will function correctly.