If you’re dealing with the frustration of a 2006-2009 Buick LaCrosse that shifts harshly, gets stuck in gear, or has a persistent check engine light, you’ve likely pinpointed the culprit: a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen firsthand how a faulty T42 TCM can wreak havoc on an otherwise reliable GM vehicle. This isn’t just an inconvenience; it affects your car’s performance, fuel economy, and safety. That’s why we offer a dependable, direct-fit solution.
This OEM-quality T42 Transmission Control Module, part number 24256960, is the definitive fix for these common issues. The most significant benefit we provide is the complimentary VIN programming. Before we ship the module, we flash it with your LaCrosse’s specific Vehicle Identification Number and the latest GM software. This means it arrives at your door ready for a true plug-and-play installation, completely bypassing the need for an expensive and time-consuming trip to the dealership for programming. It’s a solution designed for both seasoned mechanics who value efficiency and DIY enthusiasts who want a straightforward, successful repair.
Case Study: A Tricky Diagnosis
I remember a 2008 Buick LaCrosse that came into the shop with a complaint of intermittent, bone-jarring shifts from 1st to 2nd gear, but only after it warmed up. The owner had already replaced two shift solenoids with no luck. A quick scan pulled a generic P0700 code. Instead of just throwing more parts at it, we monitored the TCM data stream. We saw erratic command signals, a classic sign of internal module failure caused by heat and vibration. We installed one of our VIN-programmed T42 modules. The car immediately shifted perfectly. The customer saved hundreds by avoiding further incorrect repairs and dealership programming fees. This highlights why replacing the 2006-2009 LaCrosse TCM is often the correct, and most cost-effective, final repair.
Is Your LaCrosse Exhibiting These Transmission Issues?
A failing TCM will give you clear warning signs. If you’re experiencing any of the following, it’s highly likely your module is the problem:
- ✔ Harsh, erratic, or delayed gear shifts.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, or other solenoid-related codes.
- ✔ Complete failure to upshift or downshift.
- ✔ A noticeable drop in fuel efficiency.
- ✔ The transmission seems to be overheating for no reason.
A Straightforward Guide to Installation
One of the best parts about this repair is its simplicity. You don’t need a vehicle lift or specialized transmission tools. For the 2006-2009 Buick LaCrosse, the TCM is conveniently located under the lower air cleaner housing, making it accessible from the top of the engine bay. The entire process should take less than 30 minutes.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work. This prevents short circuits and helps reset the vehicle’s electronic systems.
- Locate and Access: Remove the air cleaner assembly to gain clear access to the old TCM. It will be mounted with a few bolts and have electrical connectors attached.
- Swap the Module: Carefully unplug the wiring harnesses from the old module. Unbolt it from its mounting bracket and set it aside. Mount your new, pre-programmed module in its place and securely reconnect the wiring harnesses.
- Final Steps: Reinstall the air cleaner assembly and reconnect the battery terminal. While our programming handles the heavy lifting, it’s good practice to use a basic OBD2 scan tool to clear any stored fault codes. Start the vehicle and enjoy smooth shifting!
Solving Problems with a Quality 2006-2009 LaCrosse TCM
This module is engineered to meet or exceed original equipment specifications, ensuring long-lasting reliability. By precisely managing shift points, torque converter clutch engagement, and line pressure, it not only fixes your current problems but also helps protect your transmission from premature wear. Backed by our one-year warranty, you can purchase with confidence, knowing you’re getting a quality part that restores your vehicle’s drivability. This module is also a direct replacement for numerous other part numbers, including 24252114, 24234503, 24230461, and more.
Verified Vehicle Compatibility
While this listing is focused on the Buick LaCrosse, this versatile T42 TCM is compatible with a wide array of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E and 4L65E. Key models include:
- Buick: LaCrosse (2006-2009), Lucerne, Allure, Rainier
- Chevrolet: Silverado, Tahoe, Impala, Monte Carlo, Cobalt, HHR, Express Van
- GMC: Sierra, Yukon, Savana Van, Envoy
- Pontiac: G6, Grand Prix
- And many more models from Cadillac, Saturn, Hummer, and Saab.
Frequently Asked Questions
Do I need to do any programming or flashing myself?
No. This module comes fully programmed to your vehicle’s VIN. It is a plug-and-play solution that requires no additional dealership visits or special programming tools.
Is this part difficult to install for a DIYer?
Not at all. For the LaCrosse, it’s located under the air cleaner box and is accessible with basic hand tools. Most customers complete the installation in under 30 minutes.
How do I provide my VIN for programming?
You can enter your vehicle’s 17-digit VIN during the checkout process. This ensures we program the module specifically for your car’s configuration.
What if my part number is slightly different?
This module replaces a wide range of GM T42 TCM part numbers. Please check the interchange list in our description or contact us with your part number to confirm compatibility.
Does this come with a warranty?
Yes, this transmission control module is backed by our comprehensive one-year warranty against any defects, giving you peace of mind with your purchase.