Restore Peak Performance to Your 2009 Trailblazer
Is your 2009 Chevrolet Trailblazer suffering from mysterious engine problems, a persistent check engine light, or a frustrating no-start condition? The Engine Control Module (ECM), often called the vehicle’s main computer, is the central command center for your engine’s operations. It meticulously manages fuel delivery, ignition timing, emissions systems, and transmission functions. When it begins to fail, it can cause a cascade of issues that are often difficult to diagnose. This replacement Engine Control Module, part number 12630464, is the definitive solution to restore your vehicle’s reliability and performance.
Unlike a generic part from a salvage yard, this ECM is delivered to you fully programmed for your specific vehicle. We use your Vehicle Identification Number (VIN) to flash the module with the latest, most stable software updates directly from General Motors. This critical step ensures seamless communication between the ECM and all other vehicle modules, eliminating compatibility conflicts and guaranteeing a true plug-and-play installation. By providing your VIN at checkout, you receive a part that is precisely matched to your Trailblazer’s factory specifications.
From the Diagnostic Bay
We had a 2009 Trailblazer with the 6.0L V8 come into the shop with a complaint of intermittent stalling at stoplights and a check engine light that would come and go. The owner had already replaced the spark plugs, ignition coils, and even the throttle body with no success. Our initial scan showed a handful of communication error codes (U-codes) along with a random misfire code. After hours of testing wiring harnesses and sensors, we noticed the ECM’s internal temperature was spiking just before it would stall. The internal processor was failing under heat load. We installed one of our VIN-programmed modules, performed the security relearn, and the truck ran perfectly. It’s a classic example of how a failing ECM can mimic many other component failures.
Symptoms of a Failing 2009 Trailblazer ECM
A faulty engine computer can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your ECM may be the culprit. Proper diagnosis is always recommended, but these are the most common signs:
- ✔ Persistent Check Engine Light: Codes related to processor failure, memory errors, or sensor reference voltage issues (e.g., P0601, P0606) are strong pointers.
- ✔ Engine Stalling or Misfiring: The engine may run rough, stall unexpectedly, or refuse to start at all.
- ✔ Decreased Fuel Economy: Inaccurate sensor readings and poor engine management lead to inefficient fuel consumption.
- ✔ Erratic Transmission Shifting: The ECM works with the Transmission Control Module (TCM), and a fault can cause harsh shifts, delayed engagement, or getting stuck in a gear.
- ✔ No Communication with Scan Tools: If your mechanic cannot connect their diagnostic tool to the vehicle, it often points to a complete failure of the ECM.
- ✔ Failure of Fuel Injectors or Ignition Coils: The ECM’s internal drivers can fail, preventing spark or fuel delivery to one or more cylinders.
Guaranteed Compatibility and Simple Installation
This module is a direct replacement for a wide range of GM vehicles and is interchangeable with several service numbers, ensuring a perfect match. By programming it to your VIN, we eliminate the need for expensive dealer-only tools or additional programming fees. While the physical installation is straightforward for a competent DIYer or any professional technician, a security relearn procedure (also known as a CASE relearn or anti-theft relearn) may be required after installation. This is a simple procedure that can typically be done without special tools and instructions can be readily found online.
This module is a direct replacement for the following service numbers: 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, 12678512.
Verified Fitment For:
- 2009 ENVOY (5.3L)
- 2009-2011 DTS
- 2009-2011 LUCERNE (4.6L)
- 2009 SAAB 9-7X
- 2009 SRX (4.6L)
- 2009 STS (4.4L, 4.6L)
- 2009 XLR
- 2009 TRAILBLAZER (6.0L)
- 2009 CORVETTE (ZR1)
- 2009 CTS (6.2L)
- 2009-2012 COLORADO (2.9L, 3.7L)
- 2009-2012 CANYON (2.9L, 3.7L)
- 2009-2010 HUMMER H3 (3.7L)
Frequently Asked Questions
Do I need to do anything after installing this ECM?
Because we program the module to your VIN, it is largely a plug-and-play installation. However, on most GM vehicles, you will need to perform a security relearn procedure. This syncs the new ECM with your vehicle’s anti-theft system and can usually be done in your driveway in about 30 minutes with just the key. Instructions are widely available online for your specific model.
How do I provide my VIN number?
You can enter your 17-digit VIN in the notes section during the checkout process. If you forget, you can also reply to your order confirmation email with the VIN. We cannot ship your part until we receive this information.
Is this a used part?
This is a high-quality, inspected, and tested original equipment part that has been verified to be fully functional. We then program it with the latest GM software for your vehicle, ensuring it performs to factory standards.
Will this 2009 Trailblazer ECM fix my check engine light?
If the check engine light and associated codes are being caused by a faulty ECM, then yes, this part will resolve the issue. It is essential to have a proper diagnosis performed to confirm the ECM is the point of failure and not a sensor or wiring problem.
What is the warranty on this part?
This part comes with our standard warranty against defects. Please review our full warranty policy page for complete terms and conditions.