Is Your Buick LaCrosse Shifting Erratically?
If your 2006-2009 Buick LaCrosse is suffering from harsh shifts, delayed gear engagement, or has a check engine light with transmission codes, a failing Transmission Control Module (TCM) is the most likely culprit. The TCM is the electronic brain of your automatic transmission, responsible for orchestrating every gear change and ensuring smooth, efficient operation. When it fails, it can cause a host of frustrating and potentially damaging issues. This genuine GM T42 TCM, service part number 24234503, is the definitive solution, pre-programmed to your vehicle’s specific VIN for a seamless, plug-and-play installation.
From the Diagnostic Bay
We had a 2008 Buick LaCrosse come into the shop that was giving its owner fits. The car would randomly get stuck in 3rd gear (limp mode) and throw a P0700 code, but after restarting, it would sometimes drive fine for a while. The owner had already replaced a couple of shift solenoids with no luck. We hooked up our scanner and saw erratic data coming from the TCM. Instead of a costly and time-consuming trip to the dealer for a new module and programming, we installed one of our VIN-programmed T42 units. The installation, located under the air cleaner box, took less than 20 minutes. After clearing the codes, the car shifted perfectly. The customer was thrilled to have their car back on the road without the dealership hassle and expense.
Symptoms of a Failing LaCrosse TCM
- ✔ Unpredictable or harsh shifting between gears.
- ✔ The vehicle gets stuck in a single gear, often referred to as “limp mode.”
- ✔ Illumination of the Check Engine Light or Transmission Warning Light.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults are stored.
- ✔ A noticeable decrease in fuel economy due to inefficient shifting.
- ✔ Failure to shift into higher or lower gears as needed.
- ✔ Complete loss of communication with the transmission module.
Your Direct Solution: The Programmed 2006-2009 LaCrosse TCM
This isn’t just a replacement part; it’s a complete solution. We take the guesswork and extra steps out of the repair process. By programming the module to your vehicle’s VIN before shipping, we ensure it has the latest GM software updates and is perfectly calibrated for your LaCrosse’s specific transmission and engine combination. This eliminates the need for an expensive trip to the dealership for programming, saving you both time and money. Simply install the module, clear any old codes, and your transmission’s performance will be restored to factory standards.
Key Features & Benefits
- Plug-and-Play Installation: Arrives pre-programmed to your VIN. No additional programming or setup is required.
- Restores Performance: Corrects common transmission issues like slipping, hard shifts, and fault codes, ensuring smooth and reliable operation.
- OEM Quality: Built to stringent General Motors standards for durability and longevity, providing a dependable, long-term fix.
- Cost-Effective Repair: Avoids high dealership programming fees and provides a reliable solution at a fraction of the cost.
- Broad Compatibility: Interchangeable with multiple part numbers including 24252114, 24230461, 24234274, 24239224, and more, ensuring a perfect match.
Installation Information
For the 2006-2009 Buick LaCrosse, the TCM is conveniently located under the lower air cleaner housing in the engine compartment. The replacement process is straightforward for a DIY mechanic. Always disconnect the battery’s negative terminal before starting. Once the new module is installed and the battery is reconnected, use a standard OBD2 scanner to clear any stored diagnostic trouble codes to complete the process.
Frequently Asked Questions
What does this Transmission Control Module do?
The TCM acts as the central computer for your automatic transmission. It processes information from various sensors to control shift solenoids, regulate hydraulic pressure, and manage torque converter lockup, ensuring your LaCrosse shifts smoothly and efficiently at all times.
Why is VIN programming so important for this part?
VIN programming loads your vehicle’s specific software and calibrations onto the module. Without it, the TCM won’t be able to communicate correctly with your car’s engine computer and other systems, leading to poor performance or a no-start condition. Our pre-programming makes it a true plug-and-play part.
Will this module fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem and has requested the check engine light be turned on. While this module often resolves the root cause of a P0700, it’s essential to scan for other, more specific transmission codes (e.g., P0751, P0756) to confirm the diagnosis.
Is this a difficult part to install myself?
For most individuals with basic mechanical skills and tools, this is a very manageable job. On the LaCrosse, it involves removing the air cleaner box for access. The entire process typically takes less than an hour.
Do I need to send my old part back?
No, there is no core charge for this part. You can keep your old module, eliminating the hassle and expense of return shipping.