Restore Peak Performance to Your Buick Lucerne
If your 2009-2011 Buick Lucerne is suffering from frustrating issues like intermittent stalling, a persistent Check Engine Light, rough idling, or a complete no-start condition, a failing Engine Control Module (ECM) is often the culprit. As a seasoned technician, I’ve seen firsthand how a faulty ECM can create a cascade of problems that are difficult to diagnose. This module is the central computer of your vehicle, managing everything from fuel delivery and ignition timing to transmission shifting. When it fails, your car’s performance and reliability suffer dramatically.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and extra cost out of the repair by programming this 2009-2011 Lucerne ECM specifically to your car using your Vehicle Identification Number (VIN). This means it arrives at your door with the latest GM factory software updates already installed. You can skip the expensive trip to the dealership for programming—this module is designed for a direct, plug-and-play installation.
From the Diagnostic Bay: The Intermittent Stall Case
I remember a 2010 Lucerne with the 4.6L V8 that came into my shop. The owner was at his wit’s end. He’d replaced sensors and plugs, but the car would still randomly stall at red lights and sometimes refuse to restart for 10-15 minutes. There were no consistent trouble codes, just a history of network communication errors (U-codes). After checking the wiring, we hooked up a scope to the ECM’s power and ground circuits. We found that the module’s internal voltage regulation was dropping out when it got hot. A replacement ECM, pre-programmed to the VIN, solved the problem in under an hour. It’s a classic failure mode for these units.
Is Your Lucerne Showing These Symptoms?
A failing ECM can manifest in various ways. If you’re experiencing any of the following, it’s a strong indicator that your engine computer needs attention:
- ✔ Persistent Check Engine Light (CEL)
- ✔ Diagnostic Trouble Codes (DTCs) related to internal module failure, such as P0601, P0602, P0605, or P0606.
- ✔ Unexplained stalling or engine hesitation.
- ✔ The engine cranks but refuses to start.
- ✔ Noticeable drop in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication errors with other vehicle modules (U-codes).
Your Straightforward Installation Guide
Installing your new 2009-2011 Lucerne ECM is a manageable job for a confident DIYer. Since we handle the programming, you won’t need any specialized computer equipment.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the ECM: On the 2009-2011 Lucerne with the 4.6L engine, the ECM is located in the engine bay, attached to the lower part of the air cleaner box assembly.
- Disconnect the Connectors: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket on the air cleaner box.
- Install the New Module: Mount your new, pre-programmed ECM onto the bracket and securely tighten the bolts.
- Reconnect and Finalize: Plug the electrical connectors firmly into the new module until they click into place. Reconnect the negative battery terminal. The vehicle may require a security relearn procedure, which typically involves cycling the key and waiting a few minutes.
Verified Vehicle Compatibility
This ECM is a direct fit for the 2009-2011 Buick Lucerne with the 4.6L V8 engine. It is also a fully compatible replacement for a wide range of other GM vehicles. Please verify your vehicle and options below. This module is interchangeable with service numbers: 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512.
COLORADO 09-12 (2.9L, 3.7L)
CORVETTE 09 (ZR1)
CTS 09 (6.2L)
DTS 09-11
ENVOY 09 (5.3L)
HUMMER H3 09-10 (3.7L)
LUCERNE 09-11 (4.6L)
SAAB 9-7X 09
SRX 09 (4.6L)
STS 09-10 (4.4L, 4.6L)
TRAILBLAZER 09 (6.0L)
XLR 09
Frequently Asked Questions
Do I need to have this ECM programmed by a dealer or mechanic?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s 17-digit VIN during checkout, and the module will arrive ready for installation.
Where is the ECM located on my 2010 Buick Lucerne?
For the 4.6L V8 model, the Engine Control Module is found in the engine compartment, mounted to the lower section of the air cleaner box.
What information do you need from me to program it?
We only need your vehicle’s complete 17-digit VIN. You can typically find this on your driver’s side dashboard (visible through the windshield) or on your vehicle’s registration or insurance card.
Will this fix my check engine light?
If your check engine light is caused by an internal failure of the ECM (often indicated by codes like P0601 through P0606), then this part is the correct solution to resolve the issue.
My original part has a different number. Will this still work?
Yes. This ECM, part number 12628911, is a direct replacement for several other GM service numbers, including 12636659, 12639300, and 12625453, among others. It is designed to be fully interchangeable.