If your 2006-2009 Buick Allure is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, you’ve come to the right place. As a technician with over two decades of experience, I’ve seen countless GM vehicles with these exact symptoms. The culprit is often a failing T42 Transmission Control Module (TCM). This isn’t just an inconvenience; it’s a problem that affects your car’s drivability, fuel economy, and long-term transmission health. This replacement TCM, part number 24239926, is the definitive, hassle-free solution.
The biggest hurdle with module replacement has always been the expensive and time-consuming trip to the dealership for programming. We eliminate that step entirely. By providing your vehicle’s VIN at checkout, we program the module specifically for your Allure. It arrives at your door ready for a true plug-and-play installation, loaded with the latest GM software updates. This ensures perfect communication between the engine and transmission, restoring the smooth, predictable performance you expect from your Buick.
Case Study: A Tricky Diagnosis
A customer brought in their ’08 Buick Allure with a classic complaint: intermittent harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode), with a P0700 code stored. They’d already replaced a shift solenoid on another shop’s advice, but the problem persisted. After a quick diagnostic check, I suspected the T42 TCM. These modules are notorious for internal solder joint failures caused by heat cycles. We installed one of our pre-programmed TCMs, and in under 30 minutes, the car was shifting like new. It’s a prime example of how targeting the right component first saves time, money, and a lot of frustration.
Is Your Buick Exhibiting These Symptoms?
A failing TCM will give you clear warning signs. If you’re experiencing any of the following, a replacement is likely needed to prevent further transmission damage:
- âś” Harsh, slamming, or delayed gear shifts.
- âś” The vehicle is stuck in a single gear (often called “limp mode”).
- âś” Check Engine Light or Transmission Warning Light is on.
- âś” Diagnostic Trouble Codes (DTCs) are present, especially P0700 (Transmission Control System Malfunction) or various solenoid-related codes (e.g., P0750, P0751).
- âś” Inability to upshift or downshift properly.
- âś” A noticeable drop in fuel efficiency.
- âś” The torque converter fails to lock up at highway speeds.
A Straightforward Guide to Installation
For the 2006-2009 Buick Allure, this is a job most DIY enthusiasts can handle in their own driveway. The TCM is located under the lower air cleaner housing, making it accessible with basic hand tools.
- Safety First: Disconnect the negative terminal from your car’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. Note the locking tabs to avoid damage. Then, unbolt the old module from its mounting bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place and securely reconnect the electrical harnesses. You should hear a click as they lock.
- Final Steps: Reinstall the air cleaner assembly and reconnect the battery terminal. Start the vehicle and allow it to idle for a few minutes. While not always necessary, using a basic OBD2 scanner to clear any lingering codes is good practice.
Verified Fitment for Your Vehicle
This T42 TCM is a direct replacement for part number 24239926 and is guaranteed to fit your 2006-2009 Buick Allure. It is also compatible with a wide range of other GM vehicles. Please verify your part number or contact us with your VIN to ensure perfect compatibility.
Interchangeable Part Numbers: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, 24239224, 24240400, 24241806, 24243901, 24243921, 24255280, 24256960, and more.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
It means we flash the module with your vehicle’s specific identification number (VIN) and the latest GM-approved software before shipping. This ensures it communicates perfectly with your car’s other computers right out of the box, just like an OEM part from the dealer, but without the extra cost and hassle.
Do I need any special tools for this installation?
No special tools are required. A basic socket set to remove the air cleaner housing and the module’s mounting bolts is all you typically need. The entire process should take less than an hour for most DIYers.
Will this fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While this module often resolves the root cause (like a faulty solenoid circuit inside the TCM itself), you should confirm there aren’t external wiring or solenoid issues. However, in many cases, a new TCM is the correct fix.
Is there a core charge for my old part?
No, there is no core charge. You can keep or dispose of your old module without the need to send it back to us, simplifying the repair process for you.