Is your 2009-2011 Buick Lucerne suffering from perplexing engine issues, a persistent Check Engine Light, or even a no-start condition? The Engine Control Module (ECM), the master computer of your vehicle, is often the source of these frustrating problems. This direct-fit replacement ECM, corresponding to service number 12635902, is the definitive solution to restore your vehicle’s performance, reliability, and efficiency. It arrives at your door pre-programmed with the latest GM software updates, specifically tailored to your vehicle’s Vehicle Identification Number (VIN).
From the Diagnostic Bay
We had a 2010 Lucerne with the 3.9L V6 come into the shop with a complaint that was driving the owner crazy. It would randomly stall at stoplights, but never consistently. Sometimes the transmission would shift hard, and other times the check engine light would flash for a minute and then disappear. We checked everything—fuel pressure, sensors, wiring harnesses—and couldn’t find a concrete fault. On a hunch, we monitored the live data from the ECM and noticed erratic voltage readings from the main processor under load. We swapped in a pre-programmed ECM, and it was like a different car. All the intermittent gremlins were gone. It’s a classic case of an internal ECM failure causing a cascade of confusing symptoms that a simple component swap can’t fix.
Symptoms of a Failing ECM
A failing ECM can manifest in numerous ways, often mimicking other component failures. If you’re experiencing any of the following, your engine computer may be at fault:
- ✔ Persistent Check Engine Light (CEL) with various trouble codes.
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The engine cranks but refuses to start (no-start condition).
- ✔ Communication errors with diagnostic scan tools.
- ✔ Problems with cooling fans running constantly or not at all.
Diagnosing and Replacing Your 2009-2011 Lucerne ECM
The ECM in your Buick Lucerne is located in the lower part of the air cleaner box, making it relatively accessible for replacement. While diagnosis can be complex, once the ECM is identified as the faulty component, the replacement process is straightforward with our programmed unit. By providing us with your VIN upon purchase, we ensure the module you receive is loaded with the correct software for your vehicle’s specific configuration, including engine, transmission, and emissions equipment. This eliminates the need for expensive dealership programming or specialized tools. Simply install the new module, perform the required security relearn procedure (if applicable), and get your car back on the road.
This module is a direct replacement for several GM service numbers, ensuring broad compatibility. It is a reliable solution for not only the 2009-2011 Lucerne ECM but also for a wide range of other GM cars and trucks, including models like the Chevrolet Malibu, Impala, Cobalt, HHR, Silverado, GMC Sierra, and Saturn Aura, among others. Please verify your original part number against our cross-reference list to confirm fitment.
Choosing a pre-programmed module saves you significant time and money. Dealerships often charge hundreds for programming alone, on top of the high cost of a new part. Our solution provides a cost-effective, plug-and-play alternative to get your vehicle running smoothly again. Each unit is meticulously tested to ensure it meets or exceeds original equipment specifications for performance and longevity.
Frequently Asked Questions
Do I need to do any programming after I receive this ECM?
No! We program the ECM with the latest GM software using the VIN you provide before we ship it. In most cases, you will only need to perform a simple security relearn procedure, which can be done without special tools and instructions are readily available online.
Where do I provide my vehicle’s VIN?
After you complete your purchase, you can send us a message with your 17-digit VIN. We cannot ship your order until we receive this information, as it’s essential for correct programming.
Is this compatible with other part numbers?
Yes, this ECM replaces several service numbers, including 12597125, 12612397, 12594750, 12629019, and 12611549. Please check the list in the description to ensure it matches your vehicle’s needs.
What if my car has an anti-theft system?
GM vehicles are equipped with a Passlock or Passkey anti-theft system. After installing the new ECM, you will likely need to perform a security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times.
How do I locate the ECM on my 2010 Buick Lucerne?
On the 2009-2011 Buick Lucerne, the ECM is conveniently located in the lower portion of the air cleaner filter box assembly in the engine bay.