Fix Your GM Transmission Issues with a Plug-and-Play Solution
If you’re experiencing erratic shifting, a check engine light, or your 2006 Trailblazer EXT is stuck in limp mode, a failing Transmission Control Module (TCM) is the most likely culprit. As a technician with over two decades of experience, I’ve seen these symptoms countless times. This isn’t just an annoyance; it’s a critical failure that compromises your vehicle’s performance and safety. This T42 TCM, part number 24243901, is the definitive, hassle-free solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play repair.
From the Diagnostic Bay: The Misleading Solenoid Codes
A customer recently brought in a 2008 Sierra with the classic signs: harsh 1-2 shift and a persistent P0752 code (Shift Solenoid ‘A’ Stuck On). He had already spent a fair amount of money replacing the solenoid inside the transmission pan, but the problem remained. This is a common trap. In my shop, I’ve diagnosed hundreds of these T42 modules. The internal circuits fail, sending false signals that mimic solenoid or sensor issues. After confirming the wiring was intact, we installed one of our VIN-programmed TCMs. The codes cleared, the truck shifted like new, and the customer was back on the road in under an hour, avoiding a costly and unnecessary internal transmission repair.
Is Your Trailblazer Exhibiting These Transmission Faults?
A faulty TCM can manifest in various ways, often being misdiagnosed. Before you consider an expensive transmission rebuild, check if you’re experiencing any of these common indicators. Replacing the 2006 Trailblazer EXT TCM is often the correct and most cost-effective fix.
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ Vehicle is stuck in one gear (often 2nd or 3rd), also known as “limp mode.”
- ✔ The Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as the general P0700 or specific solenoid codes (P0750-P0758).
- ✔ Inconsistent or no shifting, leading to poor acceleration and terrible fuel economy.
- ✔ Communication errors with the transmission module on a professional scan tool.
A Straightforward Guide to Your TCM Replacement
One of the best features of this module is its ease of installation. You don’t need specialized tools or a trip to the dealership. For a 2006 Trailblazer EXT TCM replacement, the module is conveniently located in the engine bay, making for a quick swap.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On your Trailblazer, the TCM is typically found in the left-hand (driver’s side) engine compartment. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unclip the wiring harnesses. Then, unbolt the module from its mounting bracket. The old unit will now be free.
- Install the New TCM: Mount your new, pre-programmed module in the same location, securely fastening the bolts. Reconnect the wiring harnesses, ensuring they click firmly into place.
- Final Steps: Reconnect the battery terminal. Start the vehicle and let it idle for a few minutes. While not always necessary, using a basic scan tool to clear any stored historical codes is good practice. Take a test drive to confirm smooth shifting.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
It means we load your vehicle’s unique Vehicle Identification Number (VIN) and the latest GM software onto the module before we ship it. This ensures it communicates perfectly with your engine computer and other systems right out of the box, eliminating the need for expensive dealership programming.
Will this part fix a P0700 trouble code?
A P0700 is a general code indicating the TCM has detected a fault. While you should check for other specific codes, a failing TCM is a very common cause for a P0700. Replacing it with this module often resolves the root cause.
Is there a core charge for my old part?
No, there is absolutely no core charge. You can keep your old part or recycle it without the hassle of sending it back to us.
How do I know this is the right part for my vehicle?
This T42 TCM is a direct replacement for part number 24243901 and many others. You can verify fitment using the list below or by matching your original part number. Providing your VIN at checkout guarantees you receive a correctly programmed module.
Is this a difficult part for a DIYer to install?
Not at all. The installation is very straightforward, typically taking less than 30 minutes with basic hand tools. Its location in the engine bay makes it easily accessible.
Verified Vehicle Compatibility
This module is engineered to be a direct-fit replacement for a wide range of General Motors vehicles. Please confirm your model and year from the list below. This part is interchangeable with service numbers: 24252114, 24234503, 24230461, 24243901, and more.
- TRAILBLAZER EXT 06 Transmission; (LH engine compartment), (8 cylinder)
- ALLURE 06-09 Transmission; (lower air cleaner housing)
- AVALANCHE 1500 07-08 Transmission; (next to battery)
- CANYON 08-12 Transmission; (RH rear engine compartment)
- COBALT 06-10 Transmission; (LH strut tower)
- COLORADO 08-12 Transmission; (RH rear engine compartment)
- DTS 06-11 Transmission; (RH front engine compartment)
- ENVOY 06-09 Transmission; (LH engine compartment)
- EXPRESS & SAVANA VANS 06-14 Transmission; (RH engine compartment)
- G6 06-10 Transmission; (LH strut tower)
- GRAND PRIX 06-08 Transmission; (lower air cleaner housing)
- HHR 06-11 Transmission; (LH engine compartment)
- HUMMER H3 08-10 Transmission; (RH rear engine compartment)
- IMPALA 06-11 Transmission; (lower air cleaner housing)
- LACROSSE 06-09 Transmission; (lower air cleaner housing)
- LUCERNE 06-11 Transmission; (LH engine compartment)
- MALIBU 06-10 Transmission; (LH frame rail)
- MONTE CARLO 06-07 Transmission; (lower air cleaner housing)
- SIERRA & SILVERADO 1500/2500 07-13 Transmission; (next to battery)
- TAHOE & YUKON 07-09 Transmission; (next to battery)
- And many more GM models.