Restore Smooth, Reliable Shifting to Your Buick Lucerne
If you’re dealing with the frustration of a Buick Lucerne that shifts harshly, gets stuck in gear, or has an illuminated check engine light, you’re not alone. The Transmission Control Module (TCM) is the electronic brain of your automatic transmission, and when it fails, it can cause a host of drivability issues. This T42 TCM, part number 24235753, is the definitive solution, arriving expertly programmed to your vehicle’s specific VIN for a true plug-and-play repair.
A Technician’s Notebook: The Misleading P0700 Code
I had a 2008 Lucerne with the 4.6L V8 roll into my bay last month. The owner was convinced his transmission was shot. It was stuck in 3rd gear (limp mode) and had a generic P0700 (Transmission Control System Malfunction) code. Instead of quoting a multi-thousand dollar transmission rebuild, I started with the basics. A quick scan of the TCM itself revealed multiple solenoid circuit codes and communication errors. After confirming the wiring was intact, we pinpointed the T42 module as the culprit. An hour later, with a new VIN-programmed TCM installed, the car was shifting like it just left the factory. It’s a classic case where the 2006-2011 Lucerne TCM is the real problem, not the expensive mechanical parts it controls.
Is Your Lucerne Exhibiting These Transmission Issues?
A failing TCM can manifest in several ways. If you’re experiencing any of the following, this module is likely the fix you need. Proper diagnosis is always recommended, but these are the tell-tale signs I see in the shop every week.
- ✔ Harsh, slamming shifts or erratic gear changes.
- ✔ The vehicle is stuck in a single gear, often called “limp mode.”
- ✔ Check Engine Light or Transmission Warning Light is on with codes like P0700, P0750, or other solenoid-specific faults.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ Complete failure to upshift or downshift, leading to poor acceleration.
- ✔ A noticeable drop in fuel economy due to inefficient shifting.
A Straightforward Guide to Installation
One of the best parts about this repair is how accessible it is for a DIY mechanic. You don’t need a vehicle lift or specialized transmission tools. For the 2006-2011 Lucerne TCM, the process is simple and can be done in under 30 minutes.
- Safety First: Always disconnect the negative terminal from your car’s battery to prevent any electrical shorts and to help reset the vehicle’s electronic systems.
- Locate the Module: On the Buick Lucerne, the TCM is conveniently located in the engine compartment on the driver’s side (LH side), making it easy to access.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. Note their orientation. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Mount the new, pre-programmed module in place and securely reconnect the electrical harnesses. You’ll hear a click as they lock in.
- Final Steps: Reconnect the battery terminal. Start the vehicle and allow it to run for a moment. If you have a basic OBD2 scan tool, use it to clear any stored fault codes to finalize the repair.
Will This Fit My Vehicle?
This T42 Transmission Control Module is a direct-fit replacement for a wide range of General Motors vehicles. While this page is focused on the Buick Lucerne, it is also compatible with the following models. Please verify your specific model and engine options.
- Buick: Lucerne (2006-2011), LaCrosse (2006-2009), Allure (2006-2009), Rainier (2006-2007), Rendezvous (2006-2007)
- Chevrolet: Silverado, Tahoe, Suburban, Avalanche, Express, Impala, Monte Carlo, HHR, Cobalt, Colorado
- GMC: Sierra, Yukon, Savana, Envoy, Canyon
- Cadillac: DTS (2006-2011)
- Pontiac: G5, G6, Grand Prix, Pursuit
- Saturn: Vue, Aura, Ion
- Hummer: H3
- Saab: 9-7X
This module replaces part numbers: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, 24239224, 24239926, 24240400, 24241806, 24243901, 24243921, 24255280, 24256960, 24235732, 24235753, 24240449, YNXS.
Frequently Asked Questions
Do I need to take my car to a dealership for programming?
Absolutely not. This module comes pre-programmed to your car’s VIN. Just provide your VIN at checkout, and we handle the rest. It’s ready for installation right out of the box, saving you time and money.
Is this a difficult part to install myself?
Not at all. This is a great DIY-friendly repair. With basic hand tools and our installation guide above, most people can complete the job in their driveway in less than half an hour.
Will this fix my transmission’s hard shifting?
In a vast majority of cases involving these symptoms, a faulty TCM is the root cause. Replacing your old module with this new, programmed unit is the most common and effective solution for correcting harsh shifts, slipping, and limp mode.
What is a core charge? Do I need to send my old part back?
There is no core charge for this part. You can keep your old module or dispose of it without any hassle or extra fees.
What kind of warranty is included?
We stand by the quality of our parts. This 2006-2011 Lucerne TCM comes with a one-year warranty, giving you peace of mind with your purchase.