Restore Peak Performance and Reliability to Your GM Vehicle
Is your truck or SUV suffering from frustrating, hard-to-diagnose issues? A persistent check engine light, unexplained stalling, poor fuel mileage, or a complete no-start condition can often be traced back to a single, critical component: the Engine Control Module (ECM). As the brain of your vehicle’s engine, a failing ECM can cause a cascade of problems that can sideline your vehicle and lead to expensive, incorrect repairs. This replacement Engine Control Module is the definitive, reliable solution, arriving at your door pre-programmed with the latest GM software specifically for your vehicle’s VIN.
Case Study: A Tricky Diagnosis
I remember a 2009 Trailblazer with the 6.0L that came into my shop on a tow truck. The owner had been to two other places chasing an intermittent no-start and a dashboard that would occasionally flicker like a Christmas tree. They had replaced the battery, alternator, and even the ignition switch to no avail. When I hooked up my professional scan tool, the key was the U0100 code—Lost Communication With ECM/PCM. After verifying the wiring and power/ground circuits to the module were solid, it was clear the ECM itself was failing internally. We installed one of these VIN-programmed modules, and the vehicle fired right up and has been running perfectly ever since. It saved the customer from throwing more parts at a problem that required a precise solution.
Is Your Vehicle Showing These Red Flags?
A faulty ECM doesn’t always fail completely. It often starts with subtle, intermittent symptoms that can be confusing. If you’re experiencing any of the following, your ECM is a likely culprit:
- ✔ Check Engine Light is illuminated, often with communication error codes (e.g., U0100) or internal processor failure codes (P0601, P0606).
- ✔ Engine cranks but refuses to start, or starts and immediately stalls.
- ✔ Noticeable decrease in fuel economy for no apparent reason.
- ✔ Rough idling, engine hesitation, or misfires.
- ✔ Transmission shifting erratically or harshly, as the ECM communicates with the TCM.
- ✔ Unexplained loss of power or sluggish acceleration.
A Straightforward Guide to Installation
One of the biggest advantages of this module is that it arrives ready to install, saving you a trip to the dealership. While professional installation is always an option, a confident DIYer can complete this job with basic hand tools.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the ECM: On a 2009 Trailblazer, the ECM is typically found in the engine bay on the driver’s side (LH engine). Consult a repair manual for your specific model if you’re unsure.
- Disconnect the Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the module. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. There are usually two or three bolts holding it in place.
- Install the New Module: Mount your new, pre-programmed ECM onto the bracket and secure the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Final Step: In some cases, a security relearn procedure may be necessary. This can typically be done without special tools by cycling the key in the ignition. Instructions are readily available online for your specific vehicle.
Verified Compatibility for Your Vehicle
This module is a direct replacement for part number 12630464 and is interchangeable with service numbers 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, and 12678512. It is guaranteed to fit the following vehicles:
• CTS (2009) 6.2L
• DTS (2009-2011)
• SRX (2009) 4.6L
• STS (2009) 4.4L, 4.6L
• STS (2010) 4.6L
• XLR (2009) ID 12636659 or 12625453
Chevrolet:
• COLORADO (2009) All Engines
• COLORADO (2010-2012) 2.9L, 3.7L
• CORVETTE (2009) ZR1
• TRAILBLAZER (2009) 6.0L
GMC:
• CANYON (2009) All Engines
• CANYON (2010-2012) 2.9L, 3.7L
• ENVOY (2009) 5.3L
Hummer:
• H3 (2009-2010) All Engines
Buick:
• LUCERNE (2009-2011) 4.6L
Saab:
• 9-7X (2009) All Engines
Frequently Asked Questions
Do I need to do any programming after I install this?
Do I need to do any programming after I install this?
No. This module is professionally flashed with the latest GM software updates and programmed to your specific VIN before it ships. In most cases, it is a direct plug-and-play installation, though a simple key-cycle security relearn procedure may be required.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We cannot ship the part until we have this information to ensure correct programming.
Is this the right part for my 2009 Trailblazer Engine Control Module?
Yes, this is the correct ECM for a 2009 Chevrolet Trailblazer. It is also a direct replacement for a wide range of other GM vehicles. Please check the detailed compatibility list to confirm your specific make, model, and engine.
What if my original part number is different?
This module is a direct replacement for several GM service numbers, including 12636659, 12639300, 12628911, and others listed in the description. As long as your vehicle is on the fitment list, this module will function correctly.
Will this fix my check engine light?
If the check engine light is caused by a faulty ECM (e.g., codes P0601, U0100), then this replacement will resolve the issue. However, the check engine light can be triggered by hundreds of other potential problems. Proper diagnosis is always recommended to ensure you are replacing the correct part.