End Your Buick’s Shifting Nightmares for Good
If your 2006-2009 Buick Allure is suffering from harsh, delayed, or unpredictable shifting, a failing Transmission Control Module (TCM) is the most likely culprit. As a technician with over two decades of experience, I’ve seen these symptoms countless times. Drivers come in frustrated with a car that’s stuck in gear, has a lit check engine light, and feels unreliable on the road. This isn’t just an annoyance; it’s a safety concern. This T42 Transmission Control Module, part number 24255280, is the definitive solution, engineered to restore the crisp, smooth performance your Allure had when it was new.
The core of the problem often lies in the complex communication between your engine and transmission. The TCM is the brain of this operation, and when it fails, chaos ensues. Our module comes pre-programmed to your vehicle’s specific VIN, eliminating the need for expensive dealership programming. This means you get a true plug-and-play part that’s ready to install right out of the box, solving common Diagnostic Trouble Codes (DTCs) and getting you back on the road with confidence. Don’t let a faulty module dictate your driving experience; take control with this reliable, easy-to-install fix.
From the Diagnostic Bay: The Case of the Intermittent Limp Mode
A customer brought in a 2008 Buick LaCrosse—which shares its transmission architecture with the Allure—complaining of a very tricky issue. The car would drive perfectly for days, then suddenly slam into gear and get stuck in ‘limp mode’ (3rd gear only) with a P0700 code. They had already replaced two shift solenoids at another shop with no success. After hooking up my scan tool and monitoring live data, I noticed the TCM was intermittently dropping communication. The internal circuits were failing under heat soak. We installed one of our VIN-programmed T42 modules. The fix was immediate and permanent. This highlights why just chasing codes can be misleading; addressing the root cause with a quality 2006-2009 Allure Transmission Module is the key to a lasting repair.
Is Your Buick Exhibiting These Telltale Signs?
- ✔ Hard, banging shifts or delayed gear engagement.
- ✔ Vehicle is stuck in one gear (often called ‘limp mode’).
- ✔ Check Engine Light is on with transmission codes like P0700, P0750, or other solenoid-related faults.
- ✔ Inability to upshift or downshift, leading to poor acceleration.
- ✔ A noticeable drop in fuel economy.
- ✔ Complete loss of communication with the transmission module.
A Straightforward Guide to Your DIY Installation
For the Buick Allure, this is a repair you can confidently handle in your own garage in under 30 minutes. The module 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 electrical work.
- Locate the Module: Find the air cleaner box in your engine bay. The TCM is situated directly beneath it.
- Access the TCM: Remove the air cleaner housing to gain clear access to the transmission module.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses. You’ll hear a click as they lock in.
- Final Steps: Reinstall the air cleaner housing and reconnect the battery terminal. The pre-programming ensures it works immediately, but it’s good practice to use a basic scan tool to clear any stored fault codes.
Verified Vehicle Compatibility
While this is the correct 2006-2009 Allure Transmission Module, it is also a direct replacement for a wide range of GM vehicles. This module, also known as part number 24255280, is interchangeable with service numbers 24234503, 24252114, and more. It fits models like the Chevrolet Impala, Tahoe, Silverado; GMC Sierra, Yukon; Pontiac G6, and many others using the 4L60E, 4L65E, and similar 4-speed automatic transmissions. Please verify your specific model in the list below.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean for me?
It means we load your vehicle’s unique Vehicle Identification Number (VIN) and the latest GM software onto the module before we ship it. This makes it a true plug-and-play part, saving you from a mandatory, and often costly, programming session at a dealership.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the main computer. While this module often resolves the underlying issue causing the P0700 (like a failed solenoid driver), you should always diagnose any other specific codes (e.g., P0753, P0758) that appear alongside it. In most cases, a faulty TCM is the root cause.
Is this installation difficult for a DIYer?
Not at all. For the Buick Allure, the module is located under the air cleaner housing. With basic hand tools, the entire process of swapping the old module for this new one typically takes less than 30 minutes.
Do I need to return my old TCM?
No, there is no core charge for this part. You can keep your old module or dispose of it responsibly without any extra hassle or fees.
What if I have a different GM vehicle, like a Silverado?
This T42 TCM fits a huge range of GM cars, trucks, and SUVs from 2006-2014. The only difference is the location. For example, in a Silverado, it’s typically located next to the battery. The plug-and-play functionality remains the same across all compatible models.