Restore Peak Performance to Your Buick Lucerne
Is your 2009-2011 Buick Lucerne experiencing frustrating issues like stalling, rough idling, poor fuel economy, or a persistent check engine light? These are common indicators of a failing Engine Control Module (ECM), the central computer that manages your vehicle’s engine performance. A faulty ECM can disrupt critical functions, leading to unreliable performance and potentially leaving you stranded. This replacement ECM, part number 12639300, is the definitive solution to restore your vehicle’s original drivability and efficiency.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and extra expense out of the repair by programming the module specifically for your vehicle before it ships. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) during checkout, and our technicians will flash the unit with the latest, most stable software updates directly from GM. This ensures seamless integration with your Lucerne’s systems, just like the original module from the factory.
From the Diagnostic Bay
We had a 2010 Lucerne with the 4.6L V8 come into the shop with a very tricky intermittent no-start condition. The owner had already replaced the battery and starter. After hours of chasing wires, we noticed the fuel pump relay wasn’t always getting its ground signal from the ECM. When we connected our diagnostic tool, we’d lose communication with the module sporadically. Instead of a complex wiring repair, we swapped in a pre-programmed ECM. The car fired up instantly, and the communication was stable. This case highlighted how a failing computer can mimic a dozen other problems, and having a correctly programmed, reliable replacement is the key to an accurate and lasting repair.
Symptoms of a Failing 2009-2011 Lucerne ECM
- ✔ Check Engine Light is illuminated with various trouble codes, often related to sensors or communication errors.
- ✔ Engine stalling or shutting off unexpectedly while driving.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Rough or erratic idling and hesitation during acceleration.
- ✔ Complete no-start condition where the engine cranks but won’t fire up.
- ✔ Transmission shifting problems or harsh gear changes.
- ✔ Inconsistent or non-functional electronic systems tied to the engine.
Plug-and-Play Solution with Professional Programming
The biggest hurdle when replacing a modern vehicle’s computer is the programming. Our service eliminates this step for you. By flashing the module to your specific VIN, we ensure all factory settings, anti-theft information, and engine parameters are correct. While the unit is programmed for your vehicle, some models may require a simple ‘key relearn’ or ‘security relearn’ procedure after installation, which can often be done without special tools. This process pairs the new ECM with your vehicle’s existing keys and security system. We recommend professional installation to ensure all necessary procedures are completed correctly.
Guaranteed Compatibility
This Engine Control Module is a direct replacement for a wide range of GM vehicles and is interchangeable with the following service numbers: 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512. It is confirmed to fit the following models:
- Buick Lucerne: 2009-2011 (4.6L, located in lower part of air cleaner box)
- Cadillac CTS: 2009 (6.2L)
- 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: 2009-2010 (3.7L)
- Saab 9-7x: 2009
Frequently Asked Questions
Do I need to get this ECM programmed?
No. We handle all the programming for you before we ship the part. You must provide your vehicle’s 17-digit VIN at checkout so we can load the correct GM-certified software for your specific car.
What is a VIN and why is it so important?
The VIN (Vehicle Identification Number) is your car’s unique fingerprint. It contains information about the make, model, year, engine size, and factory options. Providing the VIN allows us to program the ECM with the exact software your vehicle needs to run correctly, ensuring full compatibility.
Is this part difficult to install?
The physical installation is straightforward as it’s a direct-fit replacement. On the 2009-2011 Lucerne, it’s located in the lower part of the air cleaner box. However, after installation, a security relearn procedure may be required to sync the new module with your keys. We always recommend installation by a qualified automotive technician.
How can I be sure my old ECM is the problem?
The symptoms listed above are strong indicators of a faulty ECM. However, they can also be caused by other issues like bad wiring or faulty sensors. The best way to be 100% certain is to have a professional mechanic perform a complete diagnostic scan to confirm the ECM is the source of the failure.
Will this fix my check engine light?
If the check engine light and associated codes are being caused by a faulty ECM, then yes, this replacement part will resolve the issue. It’s crucial to ensure that the codes are not being triggered by another failing component, such as an oxygen sensor or catalytic converter.