Is Your Buick Lucerne or Grand Prix Running Rough? The ECM Might Be the Culprit.
If you’re dealing with frustrating and unpredictable issues like stalling, poor fuel economy, a no-start condition, or an illuminated Check Engine Light with seemingly random codes, the brain of your vehicle’s engine—the Electronic Control Module (ECM)—may be failing. For owners of the dependable GM 3.8L engine found in the 2006-2008 Buick Lucerne, 2006-2009 Buick LaCrosse/Allure, and 2006-2008 Pontiac Grand Prix, a faulty ECM can turn a reliable car into a source of constant headaches. This replacement ECM, part number 12619810, is the definitive solution to restore your vehicle’s performance, reliability, and driveability.
From the Diagnostic Bay
We had a 2007 Buick Lucerne come into the shop with a complaint that was baffling the owner. The car would randomly stall at stoplights, but not always. Sometimes the transmission would shift harshly, and other times it was perfectly smooth. The check engine light was on, but the codes were all over the place—O2 sensor codes one day, misfire codes the next. After checking all the usual suspects like wiring, sensors, and grounds, we focused on the ECM. By monitoring live data, we noticed the fuel trim and ignition timing values would occasionally drop out or show erratic readings just before a stall. We swapped in a known-good, programmed ECM, and the car ran perfectly. The original module had an internal fault that was causing these ghost-like issues. It’s a classic case of how a failing computer can send you chasing problems that aren’t really there.
Key Features & Common Symptoms of a Failing ECM
- ✔ Check Engine Light: Your Check Engine Light is on, often with communication-related or multiple, unrelated trouble codes (e.g., U-codes, P0601-P0606).
- ✔ Engine Performance Problems: You may experience rough idling, engine misfires, hesitation during acceleration, or a significant drop in fuel efficiency.
- ✔ No-Start Condition: The engine cranks but refuses to start, even with a good battery and fuel supply. This can be caused by the ECM not commanding the fuel injectors or ignition coils to fire.
- ✔ Harsh or Erratic Shifting: The ECM works with the Transmission Control Module (TCM). A failing ECM can send incorrect data, leading to poor automatic transmission performance.
- ✔ Stalling: The engine may stall unexpectedly while driving or when coming to a stop, often without any warning.
- ✔ VIN-Matched Programming Included: We flash this module with the latest GM-certified software using your vehicle’s specific VIN. This ensures all systems, including anti-theft and emissions, function exactly as they did from the factory.
Why Choose a Pre-Programmed 2006-2008 Lucerne ECM?
Replacing an ECM isn’t a simple plug-and-play affair. Modern vehicles use a sophisticated Vehicle Anti-Theft System (VATS) or Passlock system that is tied directly to the ECM and the vehicle’s VIN. Installing a module without the correct programming will result in a no-start condition. Our service eliminates this problem entirely. By providing us with your VIN during checkout, you receive a module that is ready for installation. Once installed, you will only need to perform a simple security relearn procedure, which can be done without any special tools. This saves you a costly trip to the dealership for programming and gets you back on the road faster.
Guaranteed Fitment for Your 3.8L GM Vehicle
This Electronic Control Module is a direct replacement for part numbers 12600930, 12616866, 12619810, and 12509307. It is located in the lower part of the air cleaner box, making it accessible for replacement. It is compatible with the following vehicles equipped with the 3.8L V6 engine:
- 2006-2008 Buick Lucerne
- 2006-2009 Buick LaCrosse
- 2006-2009 Buick Allure (Canadian Market)
- 2006-2008 Pontiac Grand Prix
Don’t let a faulty engine computer keep your car off the road. Order this VIN-programmed ECM today and restore the precise, reliable performance your vehicle was designed to deliver.
Frequently Asked Questions
Do I need to send my old ECM back (core charge)?
This listing does not require a core return. You can keep your old part, which saves you the time and expense of shipping it back.
What is VIN programming and why is it necessary?
VIN programming involves loading your car’s unique 17-digit Vehicle Identification Number and its corresponding factory software onto the replacement ECM. This is critical for ensuring the engine, transmission, anti-theft system, and other modules communicate correctly. Without it, your vehicle will not start or run properly.
Where do I provide my VIN?
After you complete your purchase, you will need to send us a message with your vehicle’s 17-digit VIN. We cannot ship your part until we receive this information, as the programming is the first step in our fulfillment process.
Is any other programming required after installation?
After installing the module, you will need to perform a security relearn procedure, also known as a key relearn. This process syncs the new ECM with your vehicle’s anti-theft system. It typically involves a series of key cycles and can be done in your driveway without any special scan tools. We include instructions to guide you through this simple process.
Where is the ECM located on my vehicle?
On the Buick Lucerne, LaCrosse, Allure, and Pontiac Grand Prix with the 3.8L engine, the ECM is conveniently located in the lower portion of the engine’s air cleaner housing/box. This makes it relatively easy to access for replacement.