Fix Your Buick’s Shifting Problems for Good
If you’re dealing with the frustration of a 2006-2009 Buick Allure that shifts harshly, gets stuck in gear, or throws transmission-related codes, you’ve come to the right place. As a technician with over two decades of experience, I’ve seen firsthand how a failing Transmission Control Module (TCM) can make a reliable car feel unpredictable and unsafe. This isn’t just an inconvenience; it’s a core performance issue. This direct-fit T42 TCM, part number 24234274, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play repair.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 Buick LaCrosse (which uses the same T42 module as the Allure) with a complaint of intermittent, bone-jarring shifts from 1st to 2nd gear and a persistent P0700 code. They’d already replaced two shift solenoids at another shop with no success. After a quick data scan, I saw the command signals from the TCM were dropping out erratically. These modules are mounted in the engine bay where they endure constant heat cycles and vibration, which often leads to internal circuit board failure. We installed one of our VIN-programmed TCMs, and the car was shifting perfectly within 30 minutes. The problem wasn’t the transmission’s mechanical parts; it was the brain controlling them.
Is Your Buick Experiencing These Transmission Issues?
A faulty TCM can manifest in several ways. If you’re noticing any of the following, it’s a strong indicator that your module needs replacement. This is especially true if you have a 2006-2009 Buick Allure TCM failure.
- âś” Harsh, slamming, or delayed gear shifts.
- âś” Vehicle enters “limp mode,” often stuck in 2nd or 3rd gear.
- âś” The Check Engine Light or Transmission Warning Light is on.
- âś” Diagnostic Trouble Codes (DTCs) are present, such as P0700 (Transmission Control System Malfunction), P0750-P0758 (Shift Solenoid codes), or other transmission-related faults.
- âś” Poor acceleration and decreased fuel economy.
- âś” Complete loss of communication with the transmission module.
A Straightforward Guide to Installation
One of the best features of this module is its ease of installation. Because it comes programmed to your VIN, you skip the expensive and time-consuming trip to the dealership. For the Buick Allure, the process is very accessible for a DIYer.
- Safety First: Disconnect the negative terminal from your car’s battery to prevent any electrical shorts and to help reset the vehicle’s adaptive memory.
- Locate the TCM: On your 2006-2009 Buick Allure, the TCM is typically found mounted to the lower air cleaner housing in the engine bay. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses from the old TCM. Then, unbolt the module from its mounting bracket.
- Install the New Module: Mount your new, pre-programmed TCM in the same location and securely fasten the bolts. Reconnect the electrical harnesses, ensuring they click into place.
- Final Steps: Reconnect the battery terminal. Start the vehicle and let it idle for a few minutes. While not always required, using a basic OBD2 scan tool to clear any stored fault codes is a best practice for a clean slate.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24234274 and other interchangeable numbers. It is guaranteed to fit the following models and more, but always confirm your specific part number for a perfect match.
- Buick Allure: 2006-2009 (Transmission; lower air cleaner housing)
- Buick LaCrosse: 2006-2009 (Transmission; lower air cleaner housing)
- Chevrolet Impala: 2006-2011 (Transmission; lower air cleaner housing)
- Chevrolet Monte Carlo: 2006-2007 (Transmission; lower air cleaner housing)
- Pontiac Grand Prix: 2006-2008 (Transmission; lower air cleaner housing)
- …and many other GM cars, trucks, and SUVs from 2006-2014. Please refer to the full fitment list.
Frequently Asked Questions
What does VIN programming mean for me?
VIN programming means we load your vehicle’s unique identification number and the latest GM software onto the module before we ship it. This ensures it communicates perfectly with your car’s engine computer and other systems right out of the box, eliminating the need for dealership programming.
Is this a difficult part to install myself?
Not at all. For most DIYers with basic hand tools, this is a very straightforward job that can be completed in under an hour. The location on the Buick Allure (under the air cleaner box) is quite accessible. Our step-by-step guide above walks you through the process.
Will this fix a P0700 diagnostic trouble code?
Yes, in many cases. The P0700 code is a general fault code indicating the TCM has detected a problem. If the root cause is the TCM itself (which is very common), replacing it with this programmed module will resolve the code and the underlying issue.
Do I need to send my old TCM back?
No, there is no core charge for this part. You can keep your old module or dispose of it, saving you the time and hassle of a return shipment.
How do I know this is the right 2006-2009 Buick Allure TCM for my car?
The best way to ensure compatibility is to match the part number on your existing module to 24234274 or one of the listed interchange numbers. You can also use our vehicle selector tool or contact our expert support team with your VIN.