Restore Smooth, Reliable Shifting to Your Buick LaCrosse
Is your 2006-2009 Buick LaCrosse suffering from jarring shifts, delayed gear engagement, or a frustrating check engine light? These are classic signs of a failing Transmission Control Module (TCM), the electronic brain that manages your vehicle’s automatic transmission. A faulty TCM can make your car unpredictable and unsafe to drive. This OEM-quality T42 TCM, part number 24235732, 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 their ’08 LaCrosse with what they described as ‘ghosts in the transmission.’ It would shift perfectly for days, then suddenly slam into gear or refuse to upshift. No single solenoid code was present, just a general P0700 (Transmission Control System Malfunction). After checking the wiring and fluid, we suspected the TCM. In my 20+ years, I’ve seen hundreds of these T42 modules fail due to internal circuit board issues caused by heat cycles and vibration. Swapping in a VIN-programmed module like this one provided an immediate, permanent fix, restoring the car’s performance and the owner’s peace of mind without a costly trip to the dealership for programming.
Is Your LaCrosse Exhibiting These Failure Symptoms?
- ✔ Harsh, erratic, or delayed gear shifts that disrupt your drive.
- ✔ The vehicle is stuck in a single gear, often called “limp mode,” as a protective measure.
- ✔ Check Engine Light or Transmission Warning Light is illuminated on your dash.
- ✔ Diagnostic Trouble Codes (DTCs) are stored, such as P0700, P0750-P0758 (solenoid circuit faults), or communication errors.
- ✔ A noticeable drop in fuel economy due to inefficient shifting and torque converter operation.
- ✔ The transmission feels like it’s slipping or failing to engage properly.
A Straightforward Guide to Your TCM Installation
Replacing your 2006-2009 LaCrosse TCM is a job most DIYers can handle in under 30 minutes with basic tools. For the LaCrosse, you’ll typically find the module located under the lower air cleaner housing, making it easily accessible in the engine bay.
- 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: Find the TCM situated beneath the air cleaner box. You may need to remove the air cleaner assembly for access.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. Press the release tabs firmly. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place and securely reconnect the electrical harnesses. You should hear a click as they lock in.
- Final Steps: Reinstall the air cleaner assembly and reconnect the battery terminal. While the module is plug-and-play, it’s always best practice to use a scan tool to verify that all codes are cleared.
Verified Vehicle Compatibility
This T42 Transmission Control Module is a direct-fit replacement for a wide range of General Motors vehicles. While this listing is for the 2006-2009 LaCrosse TCM, it is also compatible with the following models. Please verify the location noted for your specific vehicle.
- Buick: LaCrosse (06-09), Allure (06-09), Lucerne (06-11), Rainier (06-07), Rendezvous (06-07)
- Chevrolet: Avalanche 1500 (07-08), Cobalt (06-10), Colorado (08-12), Express Van (06-14), HHR (06-11), Impala (06-11), Monte Carlo (06-07), Silverado Pickup (07-13), SSR (05-06), Suburban 1500 (07-08), Tahoe (07-09)
- GMC: Canyon (08-12), Envoy / XL (06-09), Savana Van (06-14), Sierra Pickup (07-13), Yukon / XL 1500 (07-08)
- Pontiac: G5 (07-10), G6 (06-10), Grand Prix (06-08), Pursuit (06)
- Saturn: Aura (07-09), Ion (06-07), Vue (07-10)
- Cadillac: DTS (06-11)
- Hummer: H3 (08-10)
- Saab: 9-7X (06-09)
This module interchanges with part numbers: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, 24239224, 24239926, 24240400, 24241806, 24243901, 24243921, 24255280, 24256960, 24235732, 24235753, 24240449, YNXS.
Do I need to get this TCM programmed by a dealer?
Do I need to get this TCM programmed by a dealer?
No. This module comes fully pre-programmed to your vehicle’s VIN. This eliminates the need for expensive dealership programming, making it a true plug-and-play solution right out of the box.
What is a T42 TCM?
The T42 is the model name for a specific generation of Transmission Control Module used widely across GM vehicles with 4-speed automatic transmissions, like the 4L60E and 4L65E, during the mid-2000s to early 2010s.
Will this fix a P0700 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 an internal short), you should always diagnose any other specific codes (e.g., for solenoids) that appear alongside it. In many cases, a faulty TCM is the primary culprit.
Is there a core charge for my old part?
No, there is no core charge required for this part. You can keep your old module or dispose of it without the hassle of sending it back.