Restore Your Buick’s Performance with a Reliable, Programmed TCM
If your 2006-2009 Buick Allure is suffering from harsh shifting, getting stuck in gear, or has an illuminated check engine light, a failing Transmission Control Module (TCM) is the most likely culprit. As a mechanic with over two decades of experience, I’ve seen firsthand how a faulty TCM can make a perfectly good car feel unreliable and unsafe. This isn’t just an annoyance; it’s a critical failure that impacts your vehicle’s drivability and fuel economy. This replacement T42 TCM, part number 24243921, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play repair that gets you back on the road without a costly trip to the dealership.
From the Diagnostic Bay: The Case of the Hesitant Impala
A customer brought in a 2008 Impala—which uses the same T42 TCM as your Allure—with a classic complaint: “It slams into gear sometimes, and other times it feels like it’s slipping.” The check engine light was on, and my scan tool pulled a P0752 (Shift Solenoid ‘A’ Stuck On). The owner had already replaced the solenoid with no change. This is a common misstep. After 20 years in the bay, I know that when a solenoid code returns after replacement, the issue is often electrical, pointing directly at the module that controls it. The TCM’s internal drivers fail, sending incorrect signals. We installed a VIN-programmed 2006-2009 Allure TCM equivalent, and the car’s shifting was immediately smooth and responsive. The code was cleared and never returned. This story highlights why replacing the module is often the correct, and final, repair.
Is Your Allure Exhibiting These Symptoms?
A failing TCM will give you clear warning signs. Ignoring them can lead to more significant transmission damage. Watch out for these common indicators:
- ✔ Harsh, jerky, or delayed gear shifts.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0752, or other solenoid-related faults.
- ✔ Inability to upshift or downshift properly.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Intermittent loss of communication with the module.
A Straightforward Guide to Installation
One of the best features of this module is its simple installation, which a confident DIYer can complete in under 30 minutes. Your Buick Allure’s TCM is located under the lower air cleaner housing.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Access the Module: Remove the air cleaner assembly to gain clear access to the old TCM.
- 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, then securely reconnect the electrical connectors. You should hear a click as they lock in.
- Final Steps: Reinstall the air cleaner assembly and reconnect the battery terminal. Start the vehicle to confirm the fix. We recommend using a basic scan tool to clear any stored fault codes post-installation.
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of General Motors vehicles. While this listing is for the 2006-2009 Allure TCM, it is also compatible with the following models. Please verify your part number (24243921) or consult the list below.
- Buick: Allure (06-09), LaCrosse (06-09), Lucerne (06-11), Rainier (06-07), Rendezvous (06-07)
- Chevrolet: Silverado, Tahoe, Suburban, Impala, Cobalt, HHR, and more.
- GMC: Sierra, Yukon, Savana, Envoy, Canyon, and more.
- Pontiac: G6, Grand Prix, G5, and more.
- Saturn: Aura, Vue, Ion.
- And other GM models including Cadillac DTS, Hummer H3, and Saab 9-7X.
This part is interchangeable with service numbers: 24242391, 24234503, 24252114, 24243901, and others.
Frequently Asked Questions
Do I need to program this 2006-2009 Allure TCM?
No. We handle all the programming for you. Simply provide your vehicle’s VIN during checkout, and the module will arrive ready for immediate installation with the latest GM software updates.
Where is the TCM located on a 2008 Buick Allure?
On the 2006-2009 Buick Allure, the Transmission Control Module is typically found attached to the lower air cleaner housing in the engine compartment.
What happens if I don’t replace a bad TCM?
Continuing to drive with a faulty TCM can cause poor performance, terrible fuel economy, and unpredictable shifting. In the long term, it can lead to excessive wear and tear on your transmission’s mechanical components, resulting in a much more expensive repair.
Is a core charge required for this part?
No, there is no core charge. You can keep your old part, eliminating the hassle and expense of shipping it back.
What kind of warranty is included?
This module is backed by our one-year warranty, giving you confidence and peace of mind in your repair.