Restore Smooth Shifting to Your Buick LaCrosse
If you’re dealing with the frustration of a Buick LaCrosse that shifts harshly, gets stuck in gear, or throws transmission-related check engine lights, you’ve come to the right place. As a technician with over two decades of diagnostic experience, I’ve seen countless drivers worry they need a complete transmission rebuild when the real culprit is a faulty Transmission Control Module (TCM). This VIN-programmed T42 TCM, part number 24255280, is the definitive solution for restoring the precise, reliable performance your vehicle had when it left the factory.
The TCM is the brain of your automatic transmission, responsible for managing every gear change, controlling torque converter lockup, and monitoring system health. When it fails, communication breaks down, leading to the unpredictable and often jarring symptoms you’re experiencing. Our module is meticulously programmed to your vehicle’s specific VIN, ensuring it works seamlessly with your car’s systems right out of the box—no expensive trips to the dealership for programming are necessary. This is the professional-grade fix that both seasoned mechanics and determined DIYers can rely on.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 Buick LaCrosse with a classic complaint: intermittent, hard 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode). They had already replaced a shift solenoid based on a generic code, but the problem persisted. My scan tool showed a P0700 (Transmission Control System Malfunction) and an intermittent solenoid circuit code. Instead of just throwing more parts at it, I checked the live data. I noticed the TCM was commanding shifts erratically, even when all sensor inputs were normal. This pointed directly to an internal failure in the module itself. We installed one of our VIN-programmed T42 TCMs, and the car has been shifting perfectly ever since. It saved the customer from a potential transmission replacement that would have cost thousands.
Is Your Buick LaCrosse Showing These Transmission Faults?
A failing TCM can manifest in several ways. If you’re noticing any of the following, this module is the likely solution for your 2006-2009 LaCrosse TCM issues:
- ✔ Harsh, slamming, or delayed gear shifts.
- ✔ Vehicle is stuck in one gear (often called “limp mode”).
- ✔ Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, or other solenoid-specific codes.
- ✔ Poor acceleration and decreased fuel economy.
- ✔ The transmission feels like it’s slipping between gears.
- ✔ Complete loss of communication with the transmission.
A Straightforward Guide to Installation
One of the best features of this part is its simple installation, which most DIYers can complete in their driveway in under 30 minutes. For the Buick LaCrosse, the TCM is typically found under the lower air cleaner housing.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: Find the TCM, which is situated beneath the air cleaner box in your LaCrosse’s engine bay. You will need to remove the air cleaner assembly to access it.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. Then, unbolt the module from its mounting bracket and remove it from the vehicle.
- Install the New TCM: Mount the new, pre-programmed TCM in the same location, secure the bolts, and firmly reconnect the electrical connectors until they click.
- Final Steps: Reinstall the air cleaner assembly and reconnect the battery terminal. Start the vehicle to confirm the fix. While our programming resolves most issues, it’s good practice to use a basic scan tool to clear any stored historical codes.
Verified Compatibility for Your Vehicle
This T42 Transmission Control Module is a direct-fit replacement for the 2006-2009 LaCrosse TCM and is also compatible with a wide range of other General Motors vehicles. It interchanges with part numbers including 24252114, 24234503, 24230461, 24234274, 24255280, and more.
Frequently Asked Questions
Do I need to have this module programmed by a dealer?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s VIN during checkout, and the module will arrive ready for plug-and-play installation, saving you time and money.
What is a T42 TCM?
The T42 is the specific hardware platform used by General Motors for the transmission control module in many of its 4-speed automatic transmissions from the mid-2000s, including the 4L60E, 4L65E, and 4L70E found in your LaCrosse.
Is there a core charge for this part?
No, there is no core charge. You are not required to send your old, faulty module back to us, which simplifies the repair process for you.
Will this fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. In many cases where the TCM itself has failed internally, replacing it with our pre-programmed module will resolve the root cause of the P0700 and related specific codes.
What kind of warranty is included?
This module is backed by our standard one-year warranty, giving you confidence and peace of mind in your repair.