Restore a Smooth, Reliable Drive to Your Buick LaCrosse
Is your 2006-2009 Buick LaCrosse suffering from erratic shifting, getting stuck in gear, or showing a check engine light related to the transmission? These are classic signs of a failing Transmission Control Module (TCM). As the electronic brain of your automatic transmission, the TCM is responsible for every gear change and torque converter operation. When it fails, it can make your car feel unpredictable and unsafe. I’ve seen countless vehicles in my shop where owners feared a costly transmission rebuild, only to discover the root cause was a faulty TCM. This VIN-programmed T42 TCM, part number 24234503, is the definitive solution to restore your vehicle’s factory performance and peace of mind.
From the Diagnostic Bay: The Case of the Hesitant LaCrosse
A customer brought in their ’08 LaCrosse with a complaint of harsh, delayed shifts and a persistent P0700 trouble code. They were worried their 4L60E transmission was on its last legs. After a quick scan and verifying the solenoid circuits were good, my attention turned to the TCM. These modules, often located under the air cleaner housing, are exposed to constant heat and vibration, which can degrade internal electronics over time. We replaced the old unit with one of our VIN-programmed TCMs. The installation took less than 30 minutes, and the difference was immediate. The car shifted like it just rolled off the assembly line. This simple replacement saved the customer thousands of dollars and a lot of unnecessary stress.
Is Your LaCrosse Exhibiting These Transmission Faults?
A failing TCM can cause a variety of symptoms that are often misdiagnosed. If you’re experiencing any of the following, this module is likely the solution you need. A faulty 2006-2009 LaCrosse TCM can be the source of many frustrating issues.
- âś” Harsh, banging shifts or delayed gear engagement.
- âś” Vehicle stuck in “limp mode,” often in 2nd or 3rd gear.
- âś” Check Engine Light illuminated with codes like P0700 (Transmission Control System Malfunction), P0750-P0758 (Shift Solenoid codes), or other transmission-related DTCs.
- âś” Inability to upshift or downshift properly, leading to poor acceleration.
- âś” A noticeable decrease in fuel economy.
- âś” Complete loss of communication with the TCM, preventing diagnostics.
A Straightforward Guide to Installation
One of the biggest advantages of this module is its simple, plug-and-play installation. Because we program it to your vehicle’s VIN before shipping, you won’t need an expensive trip to the dealership. Most DIYers with basic tools can complete this job in under an hour.
- 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: On the 2006-2009 Buick LaCrosse, the TCM is typically found underneath the lower air cleaner housing in the engine bay. You will need to remove the airbox to access it.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Mount the new, pre-programmed TCM in the same location and securely fasten it. Reconnect the electrical harnesses, ensuring they click into place.
- Final Steps: Reinstall the air cleaner housing. Reconnect the battery terminal. Start the vehicle and allow it to idle for a few minutes. If you have a scan tool, it’s good practice to clear any stored fault codes.
Why Choose a Pre-Programmed Module?
This isn’t just a replacement part; it’s a complete repair solution. The core benefit is the VIN-specific programming. We load the latest GM-certified software for your exact vehicle, ensuring that shift points, torque converter lockup strategy, and diagnostic parameters are perfectly calibrated. This eliminates compatibility errors and provides a level of precision that a generic, non-programmed module can’t match. When you install our 2006-2009 LaCrosse TCM, you’re restoring the original factory logic that your car was designed with.
Verified Vehicle Fitment
This T42 Transmission Control Module is a direct replacement for part number 24234503 and other service numbers on a wide range of General Motors vehicles. While this listing is focused on the Buick LaCrosse, it is also compatible with the following models. Please verify your part number and model for a guaranteed fit.
- Buick: LaCrosse (2006-2009), Lucerne, Allure, Rainier, Rendezvous
- Chevrolet: Silverado, Tahoe, Suburban, Impala, Monte Carlo, Cobalt, HHR, Express Van
- GMC: Sierra, Yukon, Savana Van, Envoy, Canyon
- Pontiac: G6, Grand Prix, Pursuit
- Cadillac: DTS
- Saturn: Vue, Aura, Ion
- Hummer: H3
- Saab: 9-7X
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean for me?
It means the module arrives ready for installation with no extra steps. We flash it with your car’s specific Vehicle Identification Number (VIN), so it communicates perfectly with your engine computer and other systems right out of the box, avoiding dealership programming fees.
Do I need to send my old TCM back (core charge)?
No, there is no core charge for this part. You can keep your old module or dispose of it responsibly without the hassle of returning it.
Will this fix a P0700 diagnostic trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While a faulty TCM is a very common cause, this code can also be triggered by other issues like bad solenoids or wiring. Replacing the TCM often resolves the P0700 and any accompanying specific codes (like P0753), but proper diagnosis is always recommended.
Is this part difficult for a DIYer to install?
Not at all. For the Buick LaCrosse, the module is located under the air filter box. With basic hand tools like a socket set, the replacement can typically be done in 30-45 minutes. Disconnecting the battery is the most critical step.
What is the warranty on this transmission control module?
This module comes with a one-year warranty, giving you confidence and peace of mind in your repair.