Restore Your Buick’s Smooth, Confident Ride
If you’re dealing with the frustration of a 2006-2009 Buick LaCrosse that shifts harshly, hesitates, or has a stubborn check engine light, you’re not alone. Over my 20+ years in the garage, I’ve seen countless GM vehicles with these exact symptoms, and the culprit is often a failing Transmission Control Module (TCM). This isn’t just an annoyance; it’s a critical component failure that can affect your car’s reliability and safety. This T42 TCM, part number 24239224, is the definitive, hassle-free solution to get your LaCrosse driving like new again.
The beauty of this module is that it arrives at your door fully programmed to your vehicle’s specific VIN. That means you can skip the expensive trip to the dealership for programming. It’s a direct-fit, plug-and-play fix that restores the precise electronic control your automatic transmission needs for smooth gear changes, proper torque converter lockup, and optimal fuel economy. Stop guessing with other parts and solve the problem at its source.
From the Diagnostic Bay: The Misleading Solenoid Code
A customer brought in a 2008 LaCrosse with what seemed like a classic case of a bad shift solenoid. The car was banging into gear and had a P0752 code (Shift Solenoid ‘A’ Stuck On). The owner had already replaced the solenoid himself, but the problem persisted. Instead of jumping straight to a costly transmission teardown, we hooked up our high-level scanner and monitored the TCM’s commands. We saw the module was commanding the solenoid erratically, even when it shouldn’t have been. The root cause wasn’t the solenoid at all; it was a faulty driver inside the TCM. We installed one of our VIN-programmed T42 modules, and in less than an hour, the car was shifting perfectly. The code was gone for good. This is a prime example of how a failing TCM can mimic other, more expensive, internal transmission problems.
Diagnosing the Problem: Is Your LaCrosse Exhibiting These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission shutdown. It often starts with subtle, intermittent issues. If you’re experiencing any of the following, it’s a strong indicator that your 2006-2009 LaCrosse TCM is the component at fault:
- ✔ Harsh, slamming, or delayed gear shifts.
- ✔ The vehicle is stuck in one gear (often called ‘limp mode’).
- ✔ An illuminated Check Engine Light or Transmission Warning Light.
- ✔ Diagnostic Trouble Codes (DTCs) stored, such as the generic P0700 or specific solenoid codes (P0750-P0758).
- ✔ Inconsistent or no upshifting/downshifting.
- ✔ A noticeable drop in fuel efficiency.
- ✔ The feeling of the transmission slipping between gears.
Your 30-Minute Path to a Smooth Ride
One of the best parts about this fix is how straightforward it is for the DIY enthusiast. For the Buick LaCrosse, the TCM is conveniently located under the lower air cleaner housing, making it accessible without special lifts or tools.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electronic component replacement.
- Locate the Module: On your LaCrosse, you’ll need to remove the air cleaner box to access the TCM mounted below it.
- Swap the Part: Carefully disconnect the wiring harnesses from the old module. Unbolt it, remove it, and bolt the new, pre-programmed module in its place. Reconnect the harnesses securely.
- Final Steps: Reinstall the air cleaner box and reconnect the battery. While the battery disconnect often clears codes, it’s best practice to use a basic OBD2 scanner to confirm all transmission-related DTCs are cleared. Start the car and enjoy a smooth test drive!
Verified Fitment for Your General Motors Vehicle
While this page is dedicated to the 2006-2009 LaCrosse TCM, this versatile T42 module is compatible with a wide array of GM vehicles. It is a direct replacement for part numbers including 24252114, 24234503, 24239224, and others. Please verify your specific model below:
- Buick: LaCrosse (06-09), Allure (06-09), Lucerne (06-11), Rainier (06-07), Rendezvous (06-07)
- Chevrolet: Avalanche 1500 (07-08), Cobalt (06-10), Colorado (08-12), Express Van (06-14), HHR (06-11), Impala (06-11), Malibu (06-10), Monte Carlo (06-07), Silverado Pickup (07-13), SSR (05-06), Suburban 1500 (07-08), Tahoe (07-09)
- GMC: Canyon (08-12), Envoy / Envoy XL (06-09), Savana Van (06-14), Sierra Pickup (07-13), Yukon / Yukon XL 1500 (07-08)
- Pontiac: G5 (07-10), G6 (06-10), Grand Prix (06-08), Pursuit (06)
- Saturn: Aura (07-09), Ion (06-07), Vue (07-10)
- Cadillac: DTS (06-11)
- Hummer: H3 (08-10)
- Saab: 9-7X (06-09)
Frequently Asked Questions
What exactly does ‘VIN Programmed’ mean for me?
It means this Transmission Control Module is a true plug-and-play solution. We flash it with the latest GM software specific to your car’s Vehicle Identification Number (VIN) before shipping. This eliminates the need for an expensive programming session at a dealership, saving you time and money.
How difficult is the installation on my 2007 Buick LaCrosse?
It’s very DIY-friendly. For your LaCrosse, the TCM is located directly under the air cleaner housing in the engine bay. The job requires basic hand tools and can typically be completed in under 30 minutes.
Will this part fix a P0700 trouble code?
Yes, it is a very common solution for a P0700 code. P0700 is a generic code that simply means the TCM has detected a fault and has requested the check engine light be turned on. Replacing a faulty TCM often resolves the P0700 and any other specific transmission codes that are present.
Do I have to return my old TCM? Is there a core charge?
No, there is absolutely no core charge. You can keep your old part, so there’s no need to worry about return shipping or waiting for a core refund.
What kind of warranty comes with this module?
We stand behind our parts. This TCM comes with a one-year warranty, giving you peace of mind and protection for your investment.