Restore Peak Performance to Your GM Vehicle
Is your Corvette, Silverado, or Escalade suffering from erratic engine behavior, a persistent Check Engine Light, or a frustrating no-start condition? The Engine Control Module (ECM), often called the vehicle’s brain, is the central command unit for your engine’s performance, fuel economy, and emissions. When it fails, it can cause a cascade of problems that are difficult to diagnose. This direct-replacement ECM, part number 12704475, is the definitive solution for restoring your vehicle’s factory operation and reliability.
This isn’t just a generic part off the shelf. We provide a fully programmed module tailored specifically to your vehicle. Upon purchase, you simply provide us with your Vehicle Identification Number (VIN), and our technicians will flash the unit with the latest, most stable software updates directly from GM. This ensures seamless integration and optimal performance, eliminating the need for an expensive trip to the dealership for programming. This module is a direct replacement for several part numbers, including 12704475, 12692069, 12680656, 12686383, and 12688528.
From the Diagnostic Bay
We had a 2018 Sierra 1500 in the shop that was driving the owner crazy. It would randomly stall at stoplights and occasionally refuse to start, but threw no consistent trouble codes. The owner had already replaced the battery and alternator. We connected our diagnostic tools and saw intermittent communication drops with the ECM. Instead of a clear failure code, the data stream just vanished. After confirming power and ground to the module were solid, we knew the internal processor was failing. We installed one of our VIN-programmed ECMs, performed the quick security relearn, and the truck ran perfectly. It’s a classic example of how a failing ECM can present as a ghost in the machine, and why a reliable, correctly programmed replacement is critical.
Symptoms of a Failing Engine Control Module
- ✔ Persistent Check Engine Light (CEL) illumination
- ✔ Engine stalling, stumbling, or misfiring
- ✔ Noticeable decrease in fuel efficiency
- ✔ Difficulty starting the engine or a complete no-start condition
- ✔ Poor acceleration and overall lack of power
- ✔ Transmission shifting issues or harsh shifts
- ✔ Communication errors with diagnostic scan tools
- ✔ Failure to pass state emissions testing
Your Solution: A Pre-Programmed 2018-2019 Corvette ECM
Choosing the right replacement part is crucial for a successful repair. Our process is designed to be simple and effective. By programming the module to your VIN before shipping, we handle the most complex part of the job. When you receive your 2018-2019 Corvette ECM, you can be confident it has the correct calibration for your vehicle’s specific engine, transmission, and emissions equipment. This ensures that all systems communicate correctly, restoring the precise control GM engineered into your vehicle.
Important Installation Information
Security Relearn Procedure: Upon installation, your vehicle’s anti-theft system will need to be synchronized with the new ECM. This is a standard security measure. If the vehicle does not start, a “Vehicle Theft Deterrent Relearn” must be performed. This procedure typically requires a professional scan tool with access to GM’s programming systems (such as Tis2web or Techline Connect). This is the responsibility of the installer.
Additional Relearns: Depending on your vehicle, other system initializations may be necessary after installation. These can include a Crankshaft Variation Relearn, injector flow rate programming, or other setup procedures. These are standard for this type of repair and ensure all related components are calibrated to the new module.
Guaranteed Fitment
This module is confirmed to fit a wide range of GM vehicles. Please verify your part number and check the list below to ensure compatibility:
- Corvette (2018): Electronic Control Module; (RH cowl under dash)
- Corvette (2019): Electronic Control Module; (RH cowl under dash), VIN 6 (LT4) or VIN 7 (LT1)
- Silverado 1500 (2018): Electronic Control Module; (LH front engine compartment), ID 12680656
- Sierra 1500 (2018): Electronic Control Module; (LH front engine compartment), ID 12680656
- Sierra Denali 1500 (2018): Electronic Control Module; (LH front engine compartment), ID 12686383
- Escalade & Escalade ESV (2018): Electronic Control Module; (engine compartment)
- Tahoe / Suburban 1500 (2018): Electronic Control Module; (LH front engine compartment)
- Yukon & Yukon XL 1500 (2018): Electronic Control Module; (LH front engine compartment)
- Express / Savana 2500 & 3500 (2018): Electronic Control Module; (LH rear engine compartment), 4.3L
- Cadillac XTS (2018): Electronic Control Module; (3.6L), VIN 8 (LF3)
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. This is a direct replacement that we program and ship to you.
What is a VIN and where do I find it?
The VIN is your vehicle’s unique 17-digit identification number. You can find it on your driver’s side dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
What is the security relearn and can I do it myself?
The security relearn synchronizes the new ECM with your vehicle’s anti-theft system. While some older GM models had a manual procedure, most 2018+ vehicles require a professional scan tool with GM software access. We highly recommend having a qualified technician or shop perform this step.
Is this ECM compatible with other part numbers?
Yes, this module is a direct replacement for part numbers 12704475, 12692069, 12680656, 12686383, and 12688528. If your original module has one of these numbers, this part will work for your vehicle.
Will this fix my specific problem?
This ECM will correct issues directly caused by a faulty module. While the symptoms listed are common for ECM failure, it’s essential to have your vehicle properly diagnosed by a professional to rule out other potential causes like wiring or sensor faults.