Restore Peak Performance to Your GM Truck or SUV
The Engine Control Module (ECM), often called the engine computer, is the central command center for your vehicle’s engine and transmission. It meticulously manages critical functions like fuel delivery, ignition timing, emissions systems, and automatic transmission shift points. When your ECM begins to fail, it can lead to a cascade of frustrating and potentially damaging issues, from a simple check engine light to a vehicle that won’t start at all. This replacement Engine Control Module, part number 12704476, is the definitive solution for restoring your vehicle’s factory performance and reliability.
We take the guesswork and dealership hassle out of the equation. Before this module ships, we program it using your vehicle’s unique Vehicle Identification Number (VIN). This ensures that the ECM is loaded with the correct, most up-to-date GM factory software and calibrations specific to your vehicle’s engine, transmission, and options. This critical step is essential for proper operation and avoids the compatibility issues that plague un-programmed modules.
Solving Your Vehicle’s Drivability Problems with a Programmed 2017 Tahoe ECM
A faulty ECM can manifest in numerous ways, often mimicking other sensor or component failures. Diagnosing an internal computer fault can be tricky, but it’s often the root cause of persistent, hard-to-solve problems. By replacing your old unit with our pre-programmed module, you are providing a solid foundation for your vehicle’s entire electronic system. This part is a direct replacement for several original equipment part numbers, including 12692068, 12704476, 12686382, 12674052, 12674472, and 12678815, ensuring wide compatibility across a range of GM models.
From the Diagnostic Bay
We had a 2017 Yukon Denali come into the shop with an intermittent no-start condition that was driving the owner crazy. It would be fine for weeks, then suddenly refuse to crank. Multiple shops had replaced the battery and checked the starter, but the problem persisted. After hooking up our diagnostic tools, we noticed intermittent communication loss with the engine module. On a hunch, we carefully inspected the ECM and found no external damage. The issue was internal—a hairline fracture on the circuit board that would separate when the engine bay temperature changed. A new, properly programmed 2017 Tahoe ECM (the same part) solved the problem for good. These phantom electrical issues are often traced back to the vehicle’s central computer.
Common Symptoms of a Failing ECM
- ✔ Persistent Check Engine Light (CEL) that won’t clear.
- ✔ Engine stalling, stumbling, or misfiring, especially under load.
- ✔ Vehicle refuses to start or has difficulty starting (hard start).
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Loss of power and poor acceleration.
- ✔ Communication errors when using a diagnostic scan tool.
Important Installation Information: Post-Programming Requirements
While we handle the complex VIN-specific programming, one final step is required after installation: the Vehicle Theft Deterrent (VTD) relearn procedure. This is a security handshake that syncs the new ECM to your vehicle’s existing anti-theft system and keys. Without this procedure, the vehicle will not start as a security precaution. This relearn must be performed on the vehicle using a professional scan tool with GM programming capabilities, such as GM’s Tis2web or Techline Connect software. Additionally, other procedures like a crankshaft variation relearn or injector flow rate programming may be necessary depending on your specific vehicle. This is the responsibility of the installer. We guarantee the ECM is correctly programmed to your VIN; the final on-vehicle synchronization must be completed by a qualified technician.
Vehicle Fitment:
This module is a direct replacement for the following vehicles:
- 2017 Cadillac Escalade & Escalade ESV
- 2017 Cadillac XTS (3.6L Twin Turbo LF3)
- 2017 Cadillac CTS (6.2L Supercharged & 3.6L Twin Turbo LF3)
- 2017 Cadillac ATS (3.6L Twin Turbo LF4)
- 2017 Chevrolet Corvette
- 2017 Chevrolet Tahoe
- 2017 Chevrolet Suburban 1500
- 2016-2018 Chevrolet Silverado 1500 Pickup (check ID)
- 2017 GMC Yukon & Yukon XL 1500
- 2016-2018 GMC Sierra 1500 Pickup (check ID)
- 2017-2018 GMC Sierra Denali 1500 (check ID)
Please verify your original part number or consult your mechanic to ensure compatibility.
Frequently Asked Questions
Why do I need to provide my VIN?
Your VIN is essential. It allows us to load the precise factory software and calibrations for your vehicle’s specific engine, transmission, and factory-installed options. This ensures seamless integration and proper performance, avoiding the drivability issues common with generic modules.
What is a ‘theft relearn’ and can I do it myself?
A theft relearn is a security procedure that synchronizes the new ECM with your vehicle’s keys and anti-theft system. Without it, the engine will not start. This procedure requires a professional-grade scan tool with GM-specific software (like Techline Connect). It is not a procedure that can be done without the proper equipment.
Is this part truly ‘plug and play’?
It is ‘programming-and-play’. We handle the difficult bench-programming part. You or your mechanic will still need to perform the final on-vehicle security relearn procedure after installation for the module to function.
Will this ECM fix my check engine light?
If your check engine light and associated codes are caused by an internal failure of your original ECM, this part will resolve the issue. However, it’s crucial to ensure that no external problems (like a shorted sensor or wiring) caused the original ECM to fail, as that issue could damage the new unit as well.
What part numbers does this module replace?
This module is a direct replacement for several GM part numbers, including 12692068, 12704476, 12686382, 12674052, 12674472, and 12678815.