Is Your Buick Lucerne Running Rough? The ECM Might Be the Culprit.
If your 2009, 2010, or 2011 Buick Lucerne is experiencing frustrating issues like stalling, poor fuel economy, a persistent Check Engine Light, or even a no-start condition, the problem may lie with its most critical component: the Engine Control Module (ECM). As the central computer of your vehicle, the ECM manages everything from fuel injection and ignition timing to transmission shifting and emissions control. When it fails, the symptoms can be unpredictable and difficult to diagnose, leaving you stranded and facing a costly repair bill from a dealership.
From the Diagnostic Bay
We recently had a 2010 Lucerne with the 4.6L V8 come into the shop. The owner was at his wit’s end. The car would randomly misfire and stall, but only after it was fully warmed up. He had already replaced spark plugs, coils, and even a fuel pump with no success. We connected our diagnostic tools and saw erratic data from multiple sensors, but the sensors themselves tested fine. This pointed us directly to the ECM. After installing a VIN-programmed replacement module, the car ran perfectly. It was a classic case of an internally failing computer causing ghost-like symptoms that are impossible to trace with conventional parts-swapping.
Why Choose This 2009-2011 Lucerne Engine Control Module?
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and additional expense out of the repair process. This genuine GM control module, part number 12678512, is professionally programmed with the latest GM software updates specifically for your vehicle’s Vehicle Identification Number (VIN). This critical step ensures that the module communicates flawlessly with all other systems in your Lucerne, restoring its original performance and reliability.
Common Symptoms of a Failing ECM
- ✔ Check Engine Light is illuminated with various, often inconsistent, trouble codes.
- ✔ Engine misfires, stumbles, or stalls unexpectedly.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Poor or erratic automatic transmission shifting.
- ✔ Loss of power and sluggish acceleration.
- ✔ Communication errors with diagnostic scan tools.
Plug-and-Play Installation
Because we program the module to your VIN before it ships, the installation process is straightforward for a DIY mechanic or your trusted technician. Simply disconnect the battery, locate and swap the old module with this new one, and reconnect the battery. In most cases, you will need to perform a simple security relearn procedure (often called a ‘key relearn’), which typically involves cycling the key in the ignition. This ensures the anti-theft system recognizes the new ECM. No expensive trip to the dealer for programming is required.
This module is a direct replacement for a wide range of GM service numbers, including: 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512. While it fits many vehicles, this listing guarantees correct programming for your 2009-2011 Buick Lucerne with the 4.6L engine.
Frequently Asked Questions
How do I know if my ECM is definitely the problem?
A failing ECM can mimic other issues. The best way to be certain is through professional diagnosis. However, if you’re experiencing multiple, unrelated electronic issues, inconsistent error codes, or have ruled out more common parts like sensors and coils, the ECM is a very likely suspect.
Is this module ready to install when it arrives?
Yes! This is the key benefit. We flash the module with the latest GM software and program it to the specific VIN you provide during checkout. This makes it a plug-and-play solution, saving you a trip to the dealership for expensive programming.
Where do I provide my vehicle’s VIN?
You can add your 17-digit VIN in the notes section during the checkout process. You can also reply to your order confirmation email with the VIN. We cannot ship the module until we receive this information, as the programming is essential.
What is a security relearn procedure?
This is a simple process that syncs the new ECM with your car’s anti-theft system. For most GM vehicles of this era, it involves turning the key to the ‘ON’ position for 10-12 minutes, then off, and repeating two more times. After this, the vehicle should start normally. Instructions will be included.
Will this fit other GM vehicles listed in the description?
Yes, the physical hardware (part number 12678512 and its interchanges) fits a wide variety of GM cars and trucks. However, the programming is vehicle-specific. This listing is dedicated to providing the correct programming for the 2009-2011 Buick Lucerne. If you have a different vehicle, please find the listing specific to your model to ensure correct software is loaded.