Restore Peak Performance to Your Buick LaCrosse
Is your Buick LaCrosse or other GM vehicle suffering from frustrating issues like intermittent stalling, a persistent check engine light, or erratic engine behavior? A failing Engine Control Module (ECM) is often the culprit behind these hard-to-diagnose problems. In my 20+ years as a technician, I’ve seen firsthand how a faulty ECM can mimic a dozen other sensor failures, leading to wasted time and money. This genuine, used OEM ECM, part number 12592124, is the reliable and cost-effective solution you need to get your vehicle running smoothly again.
We take the guesswork and hassle out of the repair. Unlike a generic module from a junkyard, this unit is professionally programmed to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This crucial step ensures full compatibility with your car’s systems, including the anti-theft security (Passlock/VATS). By installing the latest GM software updates, we help restore optimal fuel economy, emissions compliance, and engine performance. This is the smart way to replace a failed 2005-2008 LaCrosse ECM without the exorbitant cost and programming fees of a dealership.
Case Study: A Tricky Diagnosis
A customer brought in a 2007 Cadillac CTS 3.6L with a complaint of random stalling at stoplights and a P0171 (System Too Lean) code. The shop he’d been to had already replaced the MAF sensor and both upstream O2 sensors, with no change. When I hooked up my scan tool, I noticed the short-term fuel trims were wildly inconsistent. Instead of chasing more sensors, I monitored the ECM’s command data. I saw the injector pulse width commands were dropping out randomly for milliseconds at a time—something a sensor wouldn’t cause. We installed a VIN-programmed ECM just like this one, and the fuel trims stabilized instantly. The problem wasn’t the sensors; it was the computer processing their data incorrectly. This saved the customer from another round of expensive, unnecessary parts.
Common Signs of a Failing ECM
If you’re experiencing any of the following, a faulty engine computer could be to blame. This module is a direct solution for these common headaches:
- ✔ Check Engine Light is on with communication or internal processor codes (e.g., P0601, P0606).
- ✔ Engine stalls for no apparent reason, either while driving or at idle.
- ✔ Noticeable decrease in fuel mileage.
- ✔ The engine cranks but refuses to start.
- ✔ Poor or rough engine performance, including misfires or hesitation.
- ✔ Failure to pass state emissions testing.
- ✔ Issues with automatic transmission shifting.
A Straightforward Guide to Installation
Installing your pre-programmed 2005-2008 LaCrosse ECM is a manageable job for a confident DIYer. While specific steps may vary slightly by model, here is a general guide. Always consult a repair manual for your specific vehicle.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- Locate the ECM: On the LaCrosse and Allure, the ECM is typically found in the lower air cleaner housing. On other models like the CTS or SRX, it’s often in the engine compartment on the passenger (RH) side.
- Disconnect Wiring: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Never force them. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Note the orientation of the module.
- Install the New Module: Mount your new, VIN-programmed ECM in the same position and secure it with the original bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new ECM until they click into place. Reconnect the negative battery terminal.
- Security Relearn Procedure: In many cases, a security relearn procedure is required for the engine to start. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. Your vehicle’s specific procedure may vary.
Verified Vehicle Compatibility
This ECM is a direct replacement for service numbers 12581144, 12588472, 12592124, and 19260507. It is guaranteed to fit the following vehicles equipped with the 3.6L V6 engine (unless noted otherwise):
Allure: 2005, 2006-2008 (3.6L)
LaCrosse: 2005, 2006-2008 (3.6L)
Rendezvous: 2004-2005 (ID 19260507), 2006 (3.6L)
Cadillac:
CTS: 2004 (Base, ID 19260507 or 12592124), 2005-2006 (Base, ID 12592124), 2007 (Base)
SRX: 2004-2006 (3.6L)
After your purchase, please provide your VIN to ensure we load the correct, updated software for your exact vehicle. This is the final step to solving your engine management problems with a reliable, tested 2005-2008 LaCrosse ECM.
Do I need to do anything after installation?
Do I need to do anything after installation?
In most cases, you will need to perform a security relearn procedure (often called a VATS or Passlock relearn). This procedure syncs the new ECM to your vehicle’s anti-theft system and typically takes about 30 minutes to complete using just the ignition key. We can provide general instructions upon request.
Is this a new part?
No, this is a high-quality, used OEM (Original Equipment Manufacturer) part that has been carefully removed from a salvaged vehicle. It is inspected for physical damage and then programmed with the latest GM software for your VIN, offering OEM reliability at a significant cost savings.
How do I provide my VIN?
After you complete your purchase, you can send us a message with your vehicle’s 17-digit VIN. We cannot ship the part until we receive the VIN, as the programming is specific to your car.
Will this fix my specific problem?
This ECM is a direct solution for failures internal to the module itself, which cause a wide range of symptoms. While it fixes the most common issues, it’s essential to ensure your vehicle has been properly diagnosed. This part will not fix problems caused by faulty sensors, wiring, or other mechanical components.
What if I order the wrong part?
We strongly encourage you to verify the part number and check the compatibility list before ordering. Because this module is programmed specifically for your VIN, it cannot be easily restocked. Please contact us with your VIN before purchase if you are unsure, and we will be happy to verify fitment for you.