Restore Smooth Shifting to Your Buick LaCrosse
If you’re dealing with the frustration of a transmission that won’t shift correctly, you’re not alone. As a technician with over two decades of experience, I’ve seen countless GM vehicles, including the 2006-2009 Buick LaCrosse, come into the shop with erratic shifting, delayed gear engagement, or being stuck in ‘limp mode.’ More often than not, the culprit isn’t the entire transmission—it’s a failing Transmission Control Module (TCM). This T42 series module, part number 24252114, is the brain of your automatic transmission, and when it fails, it can cause a host of drivability issues. This replacement is a direct-fit, OEM-quality solution designed to get your car back to factory performance without a costly trip to the dealership.
This isn’t just a part; it’s a permanent fix. We pre-program each module to your vehicle’s specific VIN, ensuring it communicates flawlessly with your car’s powertrain control module (PCM) and other systems right out of the box. This critical step eliminates the need for expensive dealer-level programming tools, making it a perfect solution for both professional mechanics and savvy DIYers. By replacing your faulty 2006-2009 LaCrosse TCM, you’re not just fixing a symptom; you’re restoring the precise electronic control that your transmission relies on for optimal fuel economy, smooth gear changes, and long-term reliability.
Case Study: The LaCrosse That Dodged a Rebuild
A customer brought in their 2008 Buick LaCrosse, convinced they needed a new transmission. It was shifting hard from 1st to 2nd and occasionally wouldn’t shift out of 3rd gear at all. Another shop had quoted them over $3,000 for a transmission rebuild. I hooked up my scan tool and found a P0752 (Shift Solenoid ‘A’ Stuck On) code. While this can point to an internal issue, my experience with these T42 modules told me to check the electronics first. After confirming the solenoid wiring was intact, we swapped in one of our VIN-programmed TCMs. The total repair time was under an hour. After a quick test drive, the car shifted like it just rolled off the assembly line. The customer saved thousands and drove away with a reliable car, all thanks to a correct diagnosis of the 2006-2009 LaCrosse TCM.
Common Signs of a Failing LaCrosse TCM
- ✔ Harsh, jerky, or unpredictable gear shifts.
- ✔ The vehicle is stuck in a single gear (limp mode), often 2nd or 3rd.
- ✔ Check Engine Light or Transmission Warning Light is illuminated on the dash.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0752, or other solenoid-related faults.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ A noticeable decrease in fuel efficiency.
- ✔ The transmission feels like it’s slipping between gears.
A Straightforward Guide to Installation
- ✔ Safety First: Before starting, disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the onboard systems.
- ✔ Locate the Module: On the 2006-2009 Buick LaCrosse, the TCM is typically found underneath the lower air cleaner housing in the engine bay. You will need to remove the airbox to access it.
- ✔ Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. Press the release tabs firmly to avoid breaking them. Once disconnected, unbolt the module from its mounting bracket.
- ✔ Install the New Module: Bolt the new, pre-programmed TCM into place. Reconnect the electrical harnesses, ensuring they click securely into place.
- ✔ Reassemble and Reconnect: Reinstall the air cleaner housing. Reconnect the negative battery terminal.
- ✔ Final Steps: Start the vehicle. While our VIN programming handles the critical setup, it’s good practice to use a basic scan tool to clear any stored fault codes from the computer’s memory. Take the vehicle for a test drive to confirm smooth shifting.
Guaranteed Vehicle Compatibility
This T42 Transmission Control Module is a confirmed fit for the 2006-2009 Buick LaCrosse. It is also a direct replacement for a wide range of other General Motors vehicles that use the 4L60E, 4L65E, and 4L70E automatic transmissions. It is interchangeable with numerous part numbers, including 24252114, 24234503, 24242391, and others. Always verify the part number on your original module or contact our expert support team to ensure a perfect match for your vehicle.
Frequently Asked Questions
What does ‘VIN Programmed’ mean for me?
It means this module arrives ready for installation with no extra steps. We load the latest GM software specific to your car’s Vehicle Identification Number (VIN) before shipping. This ensures it works perfectly with your engine and transmission, avoiding the need for a dealership visit for programming.
Is this a difficult part for a DIYer to install?
Not at all. For a Buick LaCrosse, the installation is straightforward and typically takes less than an hour with basic hand tools. The main task is removing the air cleaner box to access the module. Our step-by-step guide above walks you through the process.
Do I need to send my old part back?
No, there is no core charge for this part. You can keep your old module or dispose of it, making the process hassle-free.
What kind of warranty is included?
This module is backed by our comprehensive one-year warranty, giving you peace of mind and protection against any manufacturing defects.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault request, meaning the TCM has detected a problem and asked the main computer to turn on the Check Engine Light. This module often resolves the underlying issue (like a solenoid circuit fault) that causes the P0700 code to appear.