Is Your GM Vehicle Running Rough? It Could Be The ECM.
If you’re experiencing perplexing issues like a persistent check engine light, poor fuel economy, erratic engine behavior, or even a no-start condition in your 2017-2019 Cadillac XTS, Impala, Traverse, or other compatible GM model, the root cause is often a failing Engine Control Module (ECM). As the central computer for your vehicle’s engine, the ECM is responsible for managing everything from fuel injection and ignition timing to emissions controls and transmission shifting. When it falters, the entire vehicle’s performance and reliability are compromised.
This replacement ECM, part number 12667002, is the definitive solution to restore your vehicle’s factory performance and dependability. We take the guesswork out of the repair process. Before this unit ships, we program it with the latest official GM software updates, specifically matched to your vehicle using the VIN you provide. This means no expensive trips to the dealership for programming—it arrives ready for a straightforward installation.
From the Diagnostic Bay
We had a 2018 Chevy Impala come into the shop with a really frustrating problem. The owner complained of intermittent stalling at stoplights and a weird hesitation during acceleration, but there were no consistent trouble codes—just a generic U-code every now and then. We checked fuel pressure, scanned for vacuum leaks, and tested sensors, but everything seemed fine. On a hunch, we monitored the live data stream from the ECM and noticed the short-term fuel trim values would occasionally spike erratically just before a stall. We swapped in a pre-programmed ECM, and the difference was immediate. The engine idled smoothly, the hesitation was gone, and the stalling issue never returned. It’s a classic case of a failing processor inside the module that doesn’t always throw a clear code but wreaks havoc on driveability.
Common Symptoms of a Failing ECM
A faulty engine computer can manifest in numerous ways. If you’re noticing any of the following, it’s a strong indicator that your ECM may need replacement:
- ✔ Persistent Check Engine Light (CEL) that won’t clear or returns with various codes.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Engine misfires, stumbling, or hesitation during acceleration.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The engine cranks but refuses to start.
- ✔ Intermittent stalling for no apparent reason.
- ✔ Communication errors with diagnostic scan tools.
The Solution: A VIN-Programmed 2017-2019 XTS ECM
Don’t let a faulty computer keep your vehicle off the road. This module is a direct-fit replacement for several GM vehicles and is a reliable alternative to a costly dealership part. By programming the unit to your specific VIN, we ensure that it has the correct software calibration for your engine, transmission, and factory options. This process is critical for modern vehicles, as an incorrectly programmed module can cause more problems than it solves. Our process ensures seamless integration, allowing your vehicle’s systems to communicate and function exactly as the manufacturer intended.
This module is also compatible with part numbers 12666070 and 12667189. Please verify your part number before ordering to ensure compatibility.
Vehicle Fitment:
This Engine Control Module is compatible with the following vehicles:
- Cadillac XTS: 2017-2019 (3.6L, VIN 3, LFX)
- Chevrolet Impala: 2017-2019
- Chevrolet Traverse: 2017
- Chevrolet Caprice: 2017 (3.6L)
- Chevrolet Equinox: 2017
- GMC Acadia: 2017 (Limited, VIN J)
- GMC Terrain: 2017
- Buick Enclave: 2017
- Buick Regal: 2017
- Buick Verano: 2017
Frequently Asked Questions
Is this ECM ready to install when I receive it?
Yes! This ECM comes fully programmed to your vehicle’s specific VIN with the latest GM software. In most cases, it is a plug-and-play installation, though some vehicles may require a simple security relearn procedure, which can be done without special tools.
How do I provide my VIN for programming?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). You can typically add this in the notes section during checkout or reply to your order confirmation email. We cannot ship the part until we receive your VIN.
Will this fix my check engine light?
If the check engine light is caused by a faulty ECM, then this replacement part will solve the issue. However, it’s crucial to ensure that the underlying cause of any diagnostic trouble codes (DTCs) has been addressed. For example, if a bad sensor caused the original ECM to fail, that sensor should also be replaced.
What is a security relearn procedure?
A security relearn, also known as a Passlock or anti-theft relearn, syncs the new ECM with your vehicle’s anti-theft system. For most GM vehicles, this is a simple 30-minute process that involves turning the key to the ‘ON’ position for 10 minutes, three times in a row. Instructions are readily available online for your specific model.
Is this a new or used part?
This is a high-quality, tested, and verified used OEM part. Each unit is inspected and then programmed with fresh, vehicle-specific software to ensure it functions to factory specifications.