Restore Peak Performance to Your Vehicle’s Core
As a technician with over two decades of hands-on diagnostic experience, I’ve seen firsthand how a failing Engine Control Module (ECM) can bring an otherwise healthy vehicle to a grinding halt. It’s the brain of your engine, and when it starts to falter, you get frustrating, often intermittent, problems that can be a nightmare to pinpoint. From a check engine light that won’t go away to a car that refuses to start, a faulty ECM is a critical issue. This isn’t just a replacement part; it’s a comprehensive solution designed to restore your vehicle’s reliability and performance, getting you back on the road with confidence.
This ECM, part number 12628911, is the definitive fix for a wide range of GM vehicles. The biggest hurdle in any ECM replacement is the programming. Dealerships charge a premium for this service, and it requires specialized tools. We eliminate that step entirely. When you order, simply provide your Vehicle Identification Number (VIN), and we will flash the module with the very latest GM-certified software specific to your vehicle. It arrives at your door ready for installation, saving you significant time, money, and hassle.
A Technician’s Notebook: The Intermittent No-Start Mystery
I remember a 2009 Cadillac STS that came into my bay with a classic head-scratcher: it would start perfectly for a week, then refuse to crank for two days, only to start again like nothing was wrong. The owner had replaced the battery and starter to no avail. We scanned it and found a slew of communication loss codes (U-codes) and a history code for internal processor failure (P0606). The issue was heat-soak affecting the ECM’s internal circuits. After it cooled, it worked fine. A replacement ECM, programmed to the VIN, solved the problem permanently. This is the exact solution for those ghost-in-the-machine issues that plague so many drivers.
Is Your Vehicle Showing These Signs of ECM Failure?
A failing engine computer can manifest in numerous ways. If you’re experiencing any of the following, a faulty ECM is a likely culprit. This 2009 XLR Engine Module is designed to correct these exact problems.
- ✔ Check Engine Light is on with codes like P0601, P0602, P0606, or U0100.
- ✔ Vehicle has a no-start or hard-start condition.
- ✔ Engine stalls, stumbles, or misfires intermittently.
- ✔ Noticeable decrease in fuel economy.
- ✔ Automatic transmission shifts erratically or harshly.
- ✔ Loss of communication with other vehicle modules.
- ✔ Failure to pass an emissions inspection due to ECM-related faults.
A Straightforward Guide to Installation
Installing your new ECM is a manageable job for a DIY enthusiast with basic tools. Following these steps ensures a smooth process. Remember, with our pre-programmed module, the hardest part is already done for you!
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes to allow all modules to power down completely.
- Locate the ECM: The location varies by model (see fitment list for common spots like the RH firewall or LH engine compartment). It’s a metal box with several large electrical connectors.
- Disconnect Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the module. Never force them.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New Module: Mount your new, pre-programmed ECM in place and secure it with the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new ECM until they click into place. Reconnect the negative battery terminal.
- Perform Relearn (If Necessary): While many vehicles will start and run immediately, some may require a security or crank-sensor relearn procedure. This can often be done without special tools (consult your vehicle’s service information).
Verified Compatibility Across GM Models
This ECM is a direct replacement for multiple service numbers, ensuring broad compatibility. Please verify your vehicle is on this list for a guaranteed fit. This part replaces numbers: 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512.
CADILLAC DTS 2009-2011
CADILLAC SRX 2009 (4.6L)
CADILLAC STS 2009 (4.4L, 4.6L), 2010 (4.6L)
CADILLAC XLR 2009
CHEVROLET COLORADO 2009-2012 (2.9L, 3.7L)
CHEVROLET CORVETTE 2009 (ZR1)
CHEVROLET TRAILBLAZER 2009 (6.0L)
GMC CANYON 2009-2012 (2.9L, 3.7L)
GMC ENVOY 2009 (5.3L)
HUMMER H3 / H3T 2009-2010 (3.7L)
BUICK LUCERNE 2009-2011 (4.6L)
SAAB 9-7X 2009
Choosing this tested and properly programmed 2009 XLR Engine Module is the most reliable way to solve complex electronic issues and restore your vehicle’s factory-spec operation.
Frequently Asked Questions
Why do you need my VIN?
Your VIN is essential. It allows us to load the exact, correct software from GM for your vehicle’s specific options, engine, and transmission. This ensures perfect compatibility and function right out of the box, eliminating the need for a dealership visit.
Is this a plug-and-play part?
Yes, for the vast majority of vehicles on the fitment list. Because we pre-program it to your VIN, you can typically install it and start the vehicle. Some models may require a simple security relearn procedure, which can usually be performed without any special tools.
Will this fix my check engine light?
If the check engine light is caused by an internal ECM failure (common codes include P0601-P0606), then yes, this part is the correct fix. However, you should always ensure the codes are not being caused by a different faulty sensor or wiring issue.
Do I need to send my old ECM back?
No core charge or return is required for this module. You can keep or responsibly dispose of your old part.
What if I have a different part number on my original module?
This module is a direct replacement for several service numbers, including 12636659, 12628993, and others listed above. As long as your vehicle is on the compatibility list, this ECM will function correctly as a superseding part with the newest software.