If you’re dealing with the headaches of a faulty transmission in your 2006 Chevrolet Trailblazer EXT—like harsh, unpredictable shifting, getting stuck in gear, or a persistent check engine light—you’ve come to the right place. As a technician with over two decades of experience, I’ve seen countless GM vehicles sidelined by a failing Transmission Control Module (TCM). The T42 module, in particular, is the electronic brain of your automatic transmission, and when it malfunctions, it can make your reliable SUV feel unsafe and unpredictable. This isn’t just an annoyance; it’s a critical failure that impacts drivability and fuel economy.
This is your direct, permanent fix. We offer a high-quality T42 TCM, a direct replacement for part number 24235754, that comes fully programmed to your vehicle’s specific VIN. This means no expensive trips to the dealership for programming. It’s a true plug-and-play solution designed to restore the smooth, precise shifting you expect from your Trailblazer. By managing everything from gear selection to torque converter lockup, this module eliminates the root cause of many frustrating transmission problems.
Case Study: The Ghost in the Transmission
I once had a 2006 Trailblazer EXT in my bay with a maddeningly intermittent problem. The owner said it would shift perfectly for days, then suddenly slam into gear or refuse to upshift. No codes were stored. After checking the fluid and wiring, I suspected the TCM. On these modules, heat cycles can cause internal solder joints to crack, creating intermittent open circuits. We swapped in a VIN-programmed T42 TCM, and the problem vanished instantly. The customer called a month later, thrilled that his truck was driving like new again. It’s a classic failure mode for these components.
Diagnosing a Faulty 2006 Trailblazer EXT TCM
A failing TCM can mimic other transmission issues, but there are specific symptoms to watch for. If your Trailblazer is experiencing any of the following, the T42 module is a likely culprit.
- ✔ Harsh, slamming, or erratic gear shifts.
- ✔ The vehicle feels stuck in one gear (often called ‘limp mode’).
- ✔ Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700 (Transmission Control System Malfunction) or various solenoid codes (e.g., P0751, P0756).
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ A noticeable drop in fuel efficiency.
A Straightforward Guide to Installation
One of the best parts about this solution is its simplicity. You don’t need to be a master mechanic to get your Trailblazer back in top shape. The entire process typically takes less than 30 minutes.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On the 2006 Trailblazer EXT with the 8-cylinder engine, the TCM is conveniently located in the engine compartment on the driver’s side (LH).
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. 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.
- 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.
Verified Vehicle Compatibility
This T42 TCM is a direct fit for a wide range of General Motors vehicles. While this listing is for the 2006 Trailblazer EXT, it is also compatible with the following models. Please verify your specific application.
Interchangeable Part Numbers: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, 24239224, 24239926, 24240400, and more.
- Chevrolet Trailblazer EXT (8 cylinder): 2006
- Chevrolet SSR: 2005-2006
- GMC Envoy / Envoy XL (8 cylinder): 2006-2007
- Saab 9-7X: 2006-2009
- …and many other GM cars, trucks, and SUVs from 2006-2014. Please confirm fitment for your specific vehicle.
Don’t let a faulty module keep you off the road. Order with confidence and restore your vehicle’s performance and reliability today. No core charge means you can keep your old part without any hassle.
What does ‘VIN Programmed’ actually mean for me?
It means we load the module with your vehicle’s specific Vehicle Identification Number (VIN) and the latest GM software before we ship it. This ensures it communicates perfectly with your vehicle’s other computers right out of the box, with no need for a trip to the dealer for expensive programming.
Is this something I can install myself at home?
Absolutely. For the 2006 Trailblazer EXT, the TCM is located in the engine bay and is accessible with basic hand tools. The process involves disconnecting the battery, unplugging the old module, and swapping in the new one. It’s a popular DIY repair that can be done in under 30 minutes.
Will this part fix a P0700 trouble 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 internal failure or solenoid driver issues that the TCM reports), you should ensure other potential issues like wiring or sensors have been checked. In many cases, replacing a faulty TCM is the correct fix for a P0700.
Is there a core charge for this part?
No, there is no core charge. You are not required to send your old, faulty module back to us, saving you time and return shipping costs.
What kind of warranty is included?
This module is backed by our one-year warranty, giving you peace of mind and confidence in your repair. We stand by the quality and reliability of our programmed electronics.