Restore Peak Performance to Your Cadillac
Is your 2017 Cadillac XTS or other compatible GM vehicle suffering from perplexing issues like a persistent check engine light, rough idling, stalling, or a complete no-start condition? These are classic signs of a failing Engine Control Module (ECM), the central computer responsible for managing your vehicle’s engine performance, fuel economy, and emissions. A faulty ECM can cripple your vehicle, leaving you stranded and facing a complex repair. This replacement Engine Control Module, part number 12678815, is the definitive solution to restore your vehicle’s factory performance and reliability.
The Plug-and-Play Advantage: Pre-Programmed for Your VIN
Replacing an ECM is not as simple as swapping out a battery. Modern vehicle computers are coded specifically to the Vehicle Identification Number (VIN) of the car they belong to. Our service eliminates the most difficult step of the process. When you order, simply provide us with your vehicle’s 17-digit VIN, and our technicians will program this module with the latest, most up-to-date software directly from GM. This ensures perfect communication between the new ECM and all other modules in your vehicle, making the installation process significantly smoother. You receive a component that is ready for the final vehicle-side relearn procedures.
From the Diagnostic Bay
We recently had a 2017 Escalade come in with a ghost-in-the-machine problem. The engine would randomly misfire, the transmission would shift erratically, and multiple unrelated trouble codes were stored. The owner had already replaced spark plugs and coils with no success. After hooking up our diagnostic tools, we saw erratic data streams from the ECM. It was failing internally, sending corrupt signals across the vehicle’s network. Instead of a costly and time-consuming dealer visit, we installed one of our VIN-programmed modules. After performing the necessary security relearn, the truck started right up and ran perfectly. All the phantom codes vanished, and the owner was back on the road the same day. This highlights how a correctly programmed 2017 XTS Engine Module can solve a host of seemingly unrelated issues.
Common Symptoms of a Failing ECM
- ✔ Persistent Check Engine Light (CEL) that won’t clear.
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ A noticeable drop in fuel efficiency.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Loss of power and poor overall engine performance.
Installation and Required Relearn Procedures
While we handle the critical programming of the module to your VIN, installation requires a final, vehicle-side step. Due to the sophisticated anti-theft systems in modern GM vehicles, a Vehicle Theft Deterrent (VTD) relearn procedure must be performed after the new ECM is installed. This procedure pairs the new module with your vehicle’s security system, allowing the engine to start and run. This is not a defect but a required security feature.
IMPORTANT: The VTD relearn, along with any other potential setups like a crankshaft variation relearn or injector flow rate programming, is the responsibility of the installer. Access to a professional GM diagnostic tool (such as Tis2web or Techline Connect) is required to perform these functions. We strongly recommend professional installation if you are not familiar with these procedures.
Guaranteed Fitment and Compatibility
This module is a direct replacement for a wide range of GM trucks and SUVs. It is compatible with the following part numbers: 12692068, 12704476, 12686382, 12674052, 12674472, and 12678815. It fits models such as the Cadillac Escalade, Chevrolet Tahoe, Suburban, Silverado, GMC Sierra, Yukon, and various Cadillac sedans like the CTS and ATS. Please verify your original part number and consult the detailed fitment list to ensure this is the correct component for your vehicle.
Frequently Asked Questions
Do I need to send my old ECM to you?
No, there is no core charge or need to send in your old part. We program a replacement unit and ship it directly to you.
What information do you need from me?
After placing your order, you must provide us with your vehicle’s 17-digit VIN. This is essential for us to load the correct GM-certified software and calibrations for your specific car or truck.
What is a ‘theft relearn’ and why is it required?
A theft relearn, or VTD relearn, is a security procedure that syncs the new ECM with your vehicle’s ignition key and anti-theft system. Without this step, the vehicle will recognize the new ECM as a foreign part and will not allow the engine to start. This is a standard procedure for this type of repair.
Can I perform the theft relearn myself?
While some manual relearn procedures exist for older vehicles, most models compatible with this ECM require a professional scan tool with GM-specific software like Tis2web or Techline Connect. We recommend having a qualified mechanic perform the installation and final relearn procedures.
Is this part new or used?
This is a high-quality, tested replacement part that has been meticulously inspected and prepared to ensure it meets or exceeds OEM specifications. It is then loaded with fresh, vehicle-specific software.
Will this fix my vehicle’s problem?
This module will correct any issues directly caused by a faulty ECM. However, it is crucial that your vehicle has been properly diagnosed. This part will not fix problems related to other faulty sensors, wiring, or mechanical components.