Is Your GM Vehicle Running Rough?
If your 2009 GMC Envoy, Cadillac STS, Chevy Colorado, or another compatible GM vehicle is experiencing frustrating and unpredictable issues, a failing Engine Control Module (ECM) is often the culprit. Symptoms like a persistent check engine light, poor fuel economy, engine stalling, or a complete no-start condition can bring your daily routine to a halt. The ECM is the brain of your vehicle’s engine, managing everything from fuel injection and ignition timing to emissions controls. When it fails, the entire system suffers. This replacement Engine Control Module, part number 12628911, is the definitive solution to restore your vehicle’s performance and reliability.
We had a 2009 Trailblazer with the 6.0L come in that was driving the owner crazy. It had a random, intermittent misfire on cylinder 3 that would only happen after it was fully warmed up. The owner had already replaced the spark plug, ignition coil, and even the fuel injector, but the problem persisted. We spent hours checking wiring and grounds, all to no avail. On a hunch, we connected a scope to the injector driver circuit at the ECM. Sure enough, after 20 minutes of idling, the signal for cylinder 3 started to break down. The driver inside the original ECM was failing under heat. We installed one of these pre-programmed modules, and the Trailblazer ran perfectly. It’s a classic case where the root cause is the central computer, not the components it controls.
Common Symptoms of a Failing ECM
- ✔ Persistent Check Engine Light (CEL) with various trouble codes.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Rough or erratic idling.
- ✔ Transmission shifting problems or harsh shifts.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Loss of power and overall poor engine performance.
The Plug-and-Play Solution for Your 2009 Envoy Engine Module
What sets this module apart is our professional programming service. Forget about expensive trips to the dealership for flashing and key relearning procedures. When you purchase this 2009 Envoy Engine Module, you provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). Our technicians will then flash the unit with the latest, most stable software updates directly from General Motors, ensuring it is perfectly matched to your vehicle’s specific configuration. This process guarantees compatibility with your engine, transmission, and factory options, making the installation process as simple as possible. It arrives at your door ready to be installed, saving you significant time, money, and hassle.
This module is a direct replacement for a wide range of GM vehicles and is interchangeable with numerous service numbers, including 12636659, 12639300, 12628993, and more. By using your VIN, we eliminate the guesswork and ensure you receive the correct part with the correct software for a first-time fix. The unit is meticulously inspected to meet or exceed original equipment standards for performance and longevity. Restore the precise control and communication your vehicle’s engine needs to operate at its peak.
Frequently Asked Questions
Do I need to do any programming after I receive this ECM?
No. This ECM is delivered to you fully programmed to your vehicle’s VIN. In most cases, it is a plug-and-play installation. However, some vehicles may require a security or crankshaft position sensor relearn procedure, which can be performed with a capable scan tool.
How do I provide my VIN?
After placing your order, you can add your 17-digit VIN in the notes section at checkout or reply to your order confirmation email. We cannot ship the module until we have your VIN to program it.
Is this a new or used part?
This is a high-quality, tested replacement part that has been verified for full functionality and programmed with the latest GM software for your vehicle.
Will this fix my check engine light?
If the check engine light and associated symptoms are caused by a faulty ECM, this part will resolve the issue. It is crucial to have your vehicle properly diagnosed to confirm the ECM is the point of failure before ordering.
What is the warranty on this module?
This part comes with a standard warranty that covers defects in the module itself. Please refer to our warranty policy page for complete details and duration.