Is Your GM Vehicle Running Rough or Not Starting?
A failing Engine Control Module (ECM) can be the hidden cause of countless frustrating issues, from a persistent check engine light to a car that refuses to start. The ECM is the brain of your vehicle’s engine, controlling everything from fuel mixture and ignition timing to emissions systems and transmission shifting. When it fails, the symptoms can be unpredictable and difficult to diagnose. If you’re experiencing stalling, poor fuel economy, hesitation, or other strange electrical problems, it might be time to replace your engine computer.
This genuine used GM ECM 12669908 is the reliable and cost-effective solution to get your vehicle back in top running condition. Sourced from a salvaged vehicle, this module is a direct-fit replacement for a wide range of 2017-2019 GM models, including the Cruze, Equinox, Malibu, and more. The best part? We program it specifically to your vehicle’s Vehicle Identification Number (VIN) before it ships, ensuring it has the latest factory software and calibrations straight from GM. This critical step saves you a costly trip to the dealership and simplifies the installation process.
Common Symptoms of a Failing ECM
- ✔ Check Engine Light is on with various, often unrelated, trouble codes.
- ✔ Engine stalls, misfires, or hesitates during acceleration.
- ✔ Vehicle won’t start, or starts and then immediately dies.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Automatic transmission shifts erratically or harshly.
- ✔ Communication issues with diagnostic scan tools.
- ✔ Intermittent electrical problems that seem to have no cause.
From the Diagnostic Bay
We had a 2018 Chevy Equinox come into the shop with a really bizarre problem. The owner said it would randomly stall at red lights, but only on hot days after driving for more than 30 minutes. There were no consistent trouble codes, just a history of random communication faults. We checked everything – fuel pressure, sensors, wiring harnesses – and couldn’t find a thing wrong. On a hunch, we monitored the ECM’s data stream during a long test drive. Sure enough, as the engine bay heated up, the ECM’s processor started dropping data packets before it finally commanded a shutdown. The internal circuitry was failing under heat. We replaced it with a VIN-programmed ECM just like this one, performed the security relearn, and the problem was solved instantly. It’s a classic example of how a failing computer can mimic a dozen other mechanical issues.
Why Choose Our Pre-Programmed GM ECM 12669908?
Replacing an ECM isn’t just about swapping a part. Modern vehicles have complex security systems that prevent them from starting if a new or different computer is installed. Our service eliminates the biggest headache by programming the module to your car’s VIN before we ship it. This ensures the computer is ready to communicate with the other modules in your vehicle. It’s loaded with the correct software and engine calibrations for your specific make, model, and options, restoring the performance and reliability you expect.
Installation and Required Procedures
While we handle the initial programming, some on-vehicle procedures are required after installation. This is standard for any ECM replacement on these vehicles. Please be aware that you or your mechanic will need to perform these steps:
- Physical Installation: Disconnect the battery. Carefully remove the old ECM and install the replacement unit. Reconnect all connectors and then the battery.
- Vehicle Theft Deterrent System (VTDS) Relearn: This is a mandatory step. After installation, the vehicle will not start until a security relearn is performed. This procedure pairs the new ECM to your vehicle’s security system. It MUST be done using a professional tool with access to GM’s TIS2Web programming system.
- Other Relearns: Depending on your vehicle, additional procedures may be necessary, such as a Crankshaft Position Variation Relearn, idle relearn, or injector flow rate programming. These are the responsibility of the installer and are critical for optimal engine performance.
NOTICE: We guarantee the ECM is correctly programmed to the VIN you provide. The buyer or their certified mechanic is responsible for the proper installation and completion of all necessary relearn procedures.
Guaranteed Fitment for Service No. 12669908
This module is a direct replacement for units with service number 12669908. It fits the following vehicles, but always confirm your original part number before ordering:
- ACADIA: 2017 (2.5L, VIN Z), 2018 (2.5L)
- ATS: 2017 (2.0L)
- CRUZE: 2017-2018 (Gasoline)
- CTS: 2017 (2.0L)
- EQUINOX: 2018 (1.5L, 2.0L), 2019 (1.5L, ID 12669908)
- LACROSSE: 2018 (2.5L)
- MALIBU: 2017, 2018 (1.8L, 2.0L)
- REGAL: 2018 (2.0L)
- VOLT: 2017-2018 (Gasoline)
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 this replacement ECM using the VIN you provide during checkout.
What happens if I don’t provide my VIN?
We cannot ship the part without your vehicle’s 17-digit VIN. The programming is essential for the part to function in your car. We will contact you after your purchase to request the VIN if it was not provided.
My car won’t start after I installed the ECM. Is it defective?
This is the expected behavior. You must perform the Vehicle Theft Deterrent System (VTDS) relearn using a GM-compatible scan tool (like TIS2Web). This security procedure is required to pair the new ECM to your car’s anti-theft system before it will allow the engine to start.
Is this a new part?
No, this is a genuine, used OEM part that has been sourced from a salvaged vehicle. It has been tested and is fully functional. We then load it with the latest, clean software specific to your VIN.
Can I do the theft relearn myself?
The security relearn requires professional-grade diagnostic tools with a subscription to GM’s online service (TIS2Web). It is not possible to perform with basic code readers. We strongly recommend having the installation and relearn procedures performed by a qualified automotive technician.