Restore Your Buick’s Performance and Reliability
Is your 2009-2011 Buick Lucerne suffering from frustrating issues like a persistent check engine light, erratic engine behavior, or poor fuel mileage? These are classic signs of a failing Engine Control Module (ECM), the electronic brain of your vehicle. A faulty ECM can disrupt everything from fuel delivery and spark timing to transmission shifting, making your car unreliable. This isn’t just an annoyance; it’s a core performance and safety issue that needs a dependable solution.
As a technician with over two decades of experience, I’ve seen countless drivers spend a fortune on parts they don’t need, only to find the ECM was the culprit all along. We take the guesswork and high dealership costs out of the equation. This replacement 2009-2011 Lucerne ECM is the definitive fix for these complex electronic problems. We handle the critical programming for you, ensuring a seamless and effective repair.
The No-Hassle Programming Solution
The biggest hurdle in replacing an ECM is the programming. An unprogrammed module simply won’t work, leaving your car immobile. Dealerships charge hundreds for this service alone. We eliminate that step entirely. When you order, simply provide your vehicle’s VIN. Our experts will flash this module with the latest, most stable GM factory software specific to your car. It arrives at your door ready for installation, saving you time, money, and a trip to the dealer.
Common Signs of a Failing Engine Computer
- âś” Check Engine Light is on with internal processor codes (like P0601, P0606).
- âś” The engine cranks but refuses to start.
- âś” Noticeable decrease in fuel economy.
- âś” Unexplained stalling or rough idling, especially when warm.
- âś” Harsh or erratic automatic transmission shifting.
- âś” Communication errors with diagnostic scan tools.
- âś” Loss of power or sluggish acceleration.
Case Study: A Tricky Diagnosis
A customer brought in a 2010 Lucerne with an intermittent no-start condition that had two other shops stumped. They had already replaced the battery and starter. The car would run fine for days, then suddenly refuse to crank. After checking all the basics, I noticed the cooling fans would run on high as soon as the key was turned to ‘ON’, even with a cold engine. This is a classic default mode for many GM vehicles when the ECM fails. A quick scan confirmed communication loss with the 2009-2011 Lucerne ECM. We installed one of our pre-programmed modules, and the car has been starting reliably ever since. It’s a reminder that sometimes the ‘brain’ is the source of the problem, not the muscle.
A Straightforward Guide to Installation
- âś” Safety First: Disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to ensure all systems are powered down.
- âś” Locate the ECM: On the 2009-2011 Buick Lucerne with the 4.6L V8, the ECM is conveniently located in the lower part of the air cleaner box assembly on the driver’s side of the engine bay.
- âś” Disconnect Connectors: Carefully release the locking tabs and disconnect the wiring harness connectors from the old ECM. Never force them; they should unlatch smoothly.
- âś” Remove the Old Module: Unbolt the old ECM from its mounting bracket within the air cleaner housing.
- âś” Install the New Module: Mount your new, pre-programmed ECM in the same position and secure it. Reconnect the wiring harnesses, ensuring they click securely into place.
- âś” Final Steps: Reconnect the negative battery terminal. The vehicle may require a security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes. Your vehicle is now ready to start.
Verified Vehicle Compatibility
This module, part number 12639300, is a direct replacement for a wide range of GM vehicles. It is interchangeable with service numbers 12636659, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512. While this listing is focused on the 2009-2011 Lucerne ECM, it also fits the following models (please verify your specific engine and options):
Cadillac CTS (09), XLR (09)
Chevrolet Colorado (09-12), Corvette (09), Trailblazer (09)
GMC Canyon (09-12), Envoy (09)
Hummer H3 (09-10)
Saab 9-7X (09)
Do I need to do anything after installing this ECM?
No! Because we program the module to your VIN before shipping, it is ready to install. In some cases, a simple key-cycle security relearn may be needed, but no special tools are required.
Is this a used part?
This is a high-quality, tested, and verified OEM part that has been inspected and prepared for service. We ensure it meets or exceeds original factory standards for performance and reliability.
How do I provide my VIN?
Simply enter your 17-digit Vehicle Identification Number (VIN) in the designated field during checkout. We cannot process your order without it, as the programming is specific to your vehicle.
Will this fix my check engine light?
If the check engine light is caused by an internal ECM failure (common codes P0601-P0606), then yes, this part will resolve the issue. It’s always best to have the codes read to confirm the diagnosis before ordering.
What is your warranty policy?
We stand behind our products with a comprehensive warranty. Please see the warranty tab on the product page for full details and terms of coverage.