If your 2006-2009 Buick LaCrosse is suffering from delayed, harsh, or unpredictable shifting, the problem often lies with a failing Transmission Control Module (TCM). As the electronic brain of your automatic transmission, a faulty TCM can make driving frustrating and unsafe. This direct-replacement T42 TCM, part number 24235754, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play repair that restores the smooth, reliable performance you expect from your Buick.
Over my two decades in automotive diagnostics, I’ve seen countless GM vehicles sidelined by TCM failures. The symptoms can start small—a slight hesitation or a jerky shift—but they almost always get worse, leading to limp mode or a non-responsive transmission. This isn’t just an inconvenience; it’s a critical failure that compromises vehicle control. Our VIN programming service eliminates the biggest headache of this repair: the expensive and time-consuming trip to a dealership for flashing. We handle it all for you, ensuring this module works perfectly right out of the box.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 LaCrosse with a very intermittent issue. It would shift perfectly for days, then suddenly slam into gear or refuse to upshift. There were no consistent trouble codes, just a generic P0700 (Transmission Control System Malfunction) stored in memory. After checking the fluid and wiring harness, we suspected the TCM. The internal electronics were likely failing under certain temperature conditions. We installed one of our pre-programmed T42 modules. The customer called a week later to say the car had never driven better. This simple swap solved a problem that had been plaguing him for months, saving him from a potential transmission rebuild.
Is Your Buick LaCrosse Showing These Signs?
A failing TCM will give you clear warning signs. If you’re experiencing any of the following, it’s time to consider a replacement 2006-2009 LaCrosse TCM.
- ✔ Harsh, erratic, or delayed gear shifts.
- ✔ Vehicle stuck in one gear (often called “limp mode”).
- ✔ Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults.
- ✔ Failure to shift up or down, leading to poor acceleration.
- ✔ A noticeable decrease in fuel economy.
- ✔ The transmission feels like it’s slipping between gears.
A Straightforward Guide to Installation
For the DIY enthusiast or professional mechanic, installing this module is a simple process. On the 2006-2009 LaCrosse, the TCM is located under the lower air cleaner housing, making it accessible with basic hand tools. The entire job can typically be completed in under 30 minutes.
- 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: Remove the air cleaner assembly to access the TCM mounted below it.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Mount your new, pre-programmed TCM in place of the old one and securely reconnect the electrical connectors.
- Reassemble: Reinstall the air cleaner assembly and reconnect the battery terminal.
- Final Steps: Start the vehicle. While our programming resolves most issues, it’s good practice to use a basic OBD2 scan tool to clear any old codes stored in the Powertrain Control Module (PCM).
Verified Fitment for Your Vehicle
This T42 Transmission Control Module is a guaranteed fit for the following vehicles, among others. It is a direct replacement for part numbers including 24235754, 24252114, 24234503, and more.
- Buick LaCrosse: 2006-2009 (Located under the lower air cleaner housing)
- Buick Allure: 2006-2009 (Located under the lower air cleaner housing)
- Chevrolet Impala: 2006-2011 (Located under the lower air cleaner housing)
- Pontiac Grand Prix: 2006-2008 (Located under the lower air cleaner housing)
- …and many other GM cars, trucks, and SUVs from 2006-2014.
By choosing our pre-programmed 2006-2009 LaCrosse TCM, you’re not just buying a part; you’re buying a complete, hassle-free solution. We stand behind our quality with a one-year warranty, giving you peace of mind on the road ahead.
Frequently Asked Questions
Do I need to have this module programmed by a dealer?
No. This module comes fully programmed to your car’s VIN. It is ready for installation right out of the box, saving you the time and expense of a dealership visit.
What information do you need to program it?
We require your vehicle’s 17-digit Vehicle Identification Number (VIN) to load the correct software and calibrations for your specific LaCrosse. Please provide it during checkout.
Is this an easy part for a DIYer to replace?
Yes, absolutely. On the LaCrosse, the TCM is located under the air filter box. With basic tools, most people can complete the swap in under 30 minutes.
Will this fix a P0700 trouble code?
A P0700 code indicates a general transmission fault. While a failing TCM is a very common cause, you should also check for any other specific transmission codes (like solenoid codes) to confirm the diagnosis. In many cases, replacing the TCM will resolve the root cause of the P0700 code.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old module without any hassle or need to return it.