Restore Your Buick’s Smooth Ride
If your 2006-2009 Buick LaCrosse is suffering from harsh shifting, getting stuck in gear, or has an illuminated Check Engine Light with transmission codes, you’re likely dealing with a failed Transmission Control Module (TCM). As a technician with over 20 years of experience, I’ve seen firsthand how a faulty TCM can make a reliable car feel unpredictable and unsafe. This isn’t just an annoyance; it’s a critical component failure that affects your vehicle’s performance, fuel economy, and overall health. This T42 series TCM, part number 24240400, is the definitive solution to restore the crisp, seamless gear changes you expect from your LaCrosse.
The biggest hurdle in replacing a TCM has always been the expensive and time-consuming trip to the dealership for programming. We eliminate that step entirely. By providing us with your vehicle’s VIN during checkout, we program the module specifically for your car. It arrives at your door with the latest GM software updates, ready for a true plug-and-play installation. This ensures perfect communication between the engine and transmission, solving common diagnostic trouble codes (DTCs) right out of the box. A properly functioning 2006-2009 LaCrosse Transmission Module is essential for managing torque converter lockup, shift points, and line pressure, directly impacting your car’s drivability and longevity.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 LaCrosse with an intermittent ‘slamming’ into gear, but no consistent check engine light. After a test drive, I suspected the TCM. On the lift, I noticed the wiring and connectors were fine, a common first check. A deep scan revealed stored history codes for solenoid performance (P0752), which pointed directly to the module’s internal logic failing under load. We installed a VIN-programmed TCM, and the problem was solved instantly. These modules often fail internally from heat cycles and vibration, causing erratic signals that don’t always trigger a light immediately. This part prevents that diagnostic headache.
Is Your LaCrosse Showing These Symptoms?
- ✔ Jarring, delayed, or erratic gear shifts that disrupt your drive.
- ✔ The vehicle is stuck in a single gear (limp mode), often 2nd or 3rd.
- ✔ Check Engine or Transmission warning lights are on, with codes like P0700 (Transmission Control System Malfunction) or other solenoid-related faults.
- ✔ A noticeable decrease in fuel efficiency.
- ✔ The transmission seems to slip, or there’s a delay when shifting from Park to Drive or Reverse.
- ✔ Complete failure to shift gears.
A Straightforward Guide to Installation
For the 2006-2009 Buick LaCrosse, this job is well within reach for a DIYer. You can have your car back to normal in under an hour.
- Safety First: Always disconnect the negative terminal on your car’s battery before beginning any electronic component replacement.
- Locate the Module: On your LaCrosse, the TCM is typically found bolted 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. Then, unbolt the old module from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed 2006-2009 LaCrosse Transmission Module into place. Securely reconnect the electrical harnesses, ensuring they click into place.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s good practice to use a basic scan tool to clear any old fault codes from the vehicle’s memory. Start the car and enjoy smooth shifting!
Guaranteed Vehicle Compatibility
This module is a direct-fit replacement for the 2006-2009 LaCrosse Transmission Module and is also compatible with a wide range of other GM vehicles. It interchanges with part numbers 24252114, 24234503, 24230461, 24234274, 24240400, and more, ensuring OEM-level function across many models. This part is engineered to meet or exceed original equipment specifications for a lasting repair.
Frequently Asked Questions
Do I need to take my car to the dealer after installing this?
No. This module comes fully programmed to your vehicle’s VIN. It is a plug-and-play solution that does not require any additional programming or trips to the dealership, saving you time and money.
What information do you need to program the module?
We only need your vehicle’s 17-digit Vehicle Identification Number (VIN). You can typically find this on your driver’s side dashboard (visible through the windshield), on the driver’s door jamb sticker, or on your vehicle’s registration and insurance documents.
Is this part difficult to install myself?
For most individuals with basic hand tools, this is a straightforward installation. On the 2006-2009 LaCrosse, the TCM is easily accessible under the air cleaner box. The entire process typically takes less than 30-60 minutes.
Does this part come with a warranty?
Yes, this transmission control module is backed by our one-year warranty, giving you confidence and peace of mind in your repair.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old part, avoiding the hassle and expense of shipping it back.