Restore Smooth, Reliable Shifting to Your Buick LaCrosse
If your 2006-2009 Buick LaCrosse is suffering from harsh shifting, getting stuck in gear, or throwing transmission codes, the culprit is often a failing Transmission Control Module (TCM). As the electronic brain of your automatic transmission, a faulty TCM can make your daily drive frustrating and unreliable. This replacement T42-style TCM, part number 24241806, is the definitive solution. We pre-program it to your vehicle’s specific VIN, ensuring it works perfectly right out of the box, with no expensive dealership trips required for programming. It’s designed to restore the precise, smooth performance you expect from your Buick.
Case Study: A Tricky Diagnosis
A customer brought in their ’08 LaCrosse with a classic complaint: the car would intermittently slam into gear and sometimes felt like it was starting in 3rd gear from a stop. They had already replaced a shift solenoid based on a code, but the problem persisted. In my shop, I’ve seen this exact scenario hundreds of times. The generic solenoid codes are often a symptom, not the cause. The root issue is frequently the TCM itself developing internal faults that corrupt communication. We installed a VIN-programmed module, cleared the codes, and the car drove like new. This is why a quality, correctly programmed 2006-2009 LaCrosse Transmission Module is critical for a lasting repair.
Is Your Buick LaCrosse Showing These Telltale Signs?
- ✔ Harsh, banging, or erratic gear shifts.
- ✔ The vehicle is stuck in “limp mode” (usually 2nd or 3rd gear only).
- ✔ Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as the general P0700 or specific solenoid codes (e.g., P0751, P0756).
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ Poor fuel economy and a feeling of lost power.
- ✔ Complete failure to shift gears.
A Straightforward 30-Minute Installation Guide
You don’t need to be a master mechanic to install this part. The process is simple and can be done with basic hand tools in your own driveway. For the 2006-2009 Buick LaCrosse, the TCM is conveniently 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.
- Locate the Module: Find the TCM, which is situated directly beneath the air cleaner box in the engine bay. You will need to remove the air cleaner assembly 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 Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses. Ensure they click into place.
- Reassemble and Reconnect: Reinstall the air cleaner assembly. Reconnect the negative battery terminal.
- Final Steps: Start the vehicle. While the module is plug-and-play, it’s best practice to use a basic OBD2 scan tool to clear any stored historical fault codes from the vehicle’s memory.
Verified Fitment for Your General Motors Vehicle
This T42 TCM is a direct replacement for part number 24241806 and other interchangeable numbers. While this page is focused on the 2006-2009 LaCrosse Transmission Module, this part also fits a wide range of GM vehicles. Please verify your specific model and year from the list below.
- Buick: LaCrosse (06-09), Allure (06-09), Lucerne (06-11), Rainier (06-07), Rendezvous (06-07)
- Chevrolet: Silverado (07-13), Tahoe (07-09), Impala (06-11), Cobalt (06-10), HHR (06-11), and more.
- GMC: Sierra (07-13), Yukon (07-09), Savana (06-14), Envoy (06-09), Canyon (08-12)
- Pontiac: G6 (06-10), Grand Prix (06-08), G5 (07-10)
- Cadillac: DTS (06-11)
- Saturn: Vue (07-10), Aura (07-09), Ion (06-07)
- …and other models listed in the full fitment chart.
Frequently Asked Questions
Do I need to get this module programmed by a dealer?
Do I need to get this module programmed by a dealer?
No. The main benefit of our service is that we pre-program the module to your car’s VIN before shipping. This makes it a true plug-and-play part, saving you the time, cost, and hassle of a dealership visit.
Where is the TCM located on my 2007 Buick LaCrosse?
Do I need to get this module programmed by a dealer?
No. The main benefit of our service is that we pre-program the module to your car’s VIN before shipping. This makes it a true plug-and-play part, saving you the time, cost, and hassle of a dealership visit.
Is this a reliable, long-term fix for my transmission problems?
Do I need to get this module programmed by a dealer?
No. The main benefit of our service is that we pre-program the module to your car’s VIN before shipping. This makes it a true plug-and-play part, saving you the time, cost, and hassle of a dealership visit.
Do I need to send my old part back?
Do I need to get this module programmed by a dealer?
No. The main benefit of our service is that we pre-program the module to your car’s VIN before shipping. This makes it a true plug-and-play part, saving you the time, cost, and hassle of a dealership visit.