Restore Peak Performance to Your GM Vehicle
Is your Chevrolet, Buick, GMC, or Cadillac suffering from perplexing issues like a persistent check engine light, stalling, poor fuel economy, or a complete no-start condition? The Engine Control Module (ECM), often called the vehicle’s main computer, is the central command center for your engine’s performance. When it fails, it can cause a cascade of frustrating and difficult-to-diagnose problems. This genuine used GM Engine Control Module, service number 12669908, is the definitive solution to get your vehicle running correctly again.
This isn’t just a replacement part; it’s a fully prepared solution. We take a tested, functional ECM from a salvaged vehicle and flash it with the latest, most up-to-date official GM software calibrations specific to your car. By providing us with your Vehicle Identification Number (VIN) during checkout, you ensure that the module you receive is precisely matched to your vehicle’s original factory specifications, including its engine, transmission, and emissions equipment. This critical step eliminates guesswork and compatibility issues, paving the way for a successful repair.
From the Diagnostic Bay
We had a 2018 Equinox come into the shop with classic signs of a failing ECM. The engine would misfire randomly, the transmission shifted harshly, and the check engine light was on with a handful of communication error codes. The owner had already replaced spark plugs and an ignition coil with no success. Before condemning the expensive computer, we performed a full diagnostic. We checked the main power and ground circuits to the ECM and found a corroded ground wire on the engine block. After cleaning the connection point and re-securing the wire, all the symptoms vanished. This is a crucial reminder: always verify the simple things like power, grounds, and connections before replacing a major electronic component. A solid diagnosis saves time, money, and frustration.
Is Your Vehicle’s Brain Failing? Common ECM Symptoms
- ✔ Check Engine Light: The most common indicator, often with codes related to internal module failure (like P0606) or communication errors.
- ✔ No-Start or Hard Starting: The ECM controls the fuel injectors and ignition coils. If it fails, it may not send the proper signals to start the engine.
- ✔ Poor Engine Performance: You might experience rough idling, stalling, hesitation during acceleration, or a noticeable loss of power.
- ✔ Reduced Fuel Economy: An improperly functioning ECM can’t efficiently manage the air-fuel mixture, leading to wasted fuel and more trips to the pump.
- ✔ Transmission Shifting Problems: The ECM works closely with the Transmission Control Module (TCM). A faulty ECM can cause erratic shifting, delayed engagement, or the transmission getting stuck in one gear.
- ✔ Intermittent Electrical Issues: Seemingly unrelated problems with cooling fans, gauges, or other electronic systems can sometimes be traced back to a failing ECM.
Why Choose Our Programmed ECM 12669908?
Choosing the right replacement ECM is critical. Our process ensures you receive a reliable, correctly configured part ready for installation. We use your VIN to access the official GM database and load the exact software your vehicle needs. This eliminates the need for expensive and time-consuming programming at a dealership. This Programmed ECM 12669908 is a cost-effective and dependable alternative to a new part, providing the same functionality and performance. Each unit is sourced from a salvaged vehicle and thoroughly inspected to ensure it is a viable component for your repair.
Installation and Relearn Procedures
Once you receive your pre-programmed ECM, the physical installation is typically straightforward, involving disconnecting the battery and swapping the module. However, a critical final step is required. Due to modern vehicle security systems, a Vehicle Theft Deterrent System Relearn must be performed after installation. This procedure syncs the new ECM with your vehicle’s keys and immobilizer system. Without it, the vehicle will not start.
NOTICE: This relearn procedure, along with any other necessary setups like a crankshaft position variation relearn or injector flow rate programming, is the responsibility of the installer. Access to a professional scan tool or GM’s TIS2Web programming system is required to complete the installation successfully. We provide the correctly programmed part; the final vehicle-side integration must be performed by a qualified technician.
Guaranteed Fitment for Service No. 12669908
This module is a direct replacement for units with service number 12669908. Please verify the number on your original ECM to ensure compatibility. This part fits a wide range of GM models, including:
- Acadia: 2017-2018 (2.5L)
- ATS: 2017 (2.0L)
- Cruze: 2017-2018 (Gasoline)
- CTS: 2017 (2.0L)
- Equinox: 2018-2019 (1.5L, 2.0L)
- LaCrosse: 2018 (2.5L)
- Malibu: 2017-2018 (1.8L, 2.0L)
- Regal: 2018 (2.0L)
- Volt: 2017-2018 (Gasoline)
Frequently Asked Questions
What is an ECM and what does it do?
The Engine Control Module (ECM) is your vehicle’s primary computer. It controls all essential engine functions, including fuel injection timing, spark timing, variable valve timing, and emissions systems, to ensure optimal performance, fuel efficiency, and low emissions.
How do I know if my ECM is the problem?
While the symptoms listed above are common indicators, a definitive diagnosis requires a professional scan tool to read fault codes and live data. It’s also crucial to rule out simpler issues like bad wiring, sensors, or ground connections before replacing the ECM.
What information do you need to program this ECM?
We require your vehicle’s 17-digit Vehicle Identification Number (VIN). This allows us to download the exact, most current software calibration from GM for your specific make, model, year, and options. Please provide your VIN in the notes section during checkout.
What is a ‘theft deterrent relearn’ and why is it necessary?
This is a security procedure that syncs the replacement ECM to your vehicle’s immobilizer system and keys. Without this step, the security system will identify the new ECM as foreign and prevent the engine from starting to protect against theft. This procedure requires a compatible professional scan tool.
Is this a plug-and-play part?
No. While it is pre-programmed to your VIN, it is not plug-and-play. After physical installation, you MUST perform the vehicle theft deterrent relearn and potentially other setup procedures (like crankshaft variation relearn) for the vehicle to start and run correctly.