If your 2006 TrailBlazer EXT is suffering from harsh, delayed, or unpredictable shifting, the problem often points directly to a failing Transmission Control Module (TCM). As a technician with over 20 years of experience, I’ve seen countless drivers worry about a complete transmission failure when the real culprit is this electronic brain. This OEM-quality T42 TCM, part number 24239926, is the definitive solution, arriving expertly programmed to your vehicle’s specific VIN for a true plug-and-play repair that restores the crisp, reliable performance you depend on.
The TCM is the nerve center of your automatic transmission, managing everything from shift points and line pressure to torque converter clutch engagement. When it fails, communication breaks down, leading to the frustrating and sometimes dangerous symptoms you’re experiencing. Our process eliminates the guesswork and the expensive trip to the dealership. We flash the module with the latest GM software tied to your VIN, so it works seamlessly with your TrailBlazer’s systems right out of the box.
From the Diagnostic Bay: The “Simple” Fix
I remember a customer with a 2006 TrailBlazer EXT who was quoted nearly $3,000 for a transmission rebuild. His SUV was stuck in third gear (limp mode) and had a P0700 code. He was ready to give up on the vehicle. I hooked up my scan tool and saw erratic data from the shift solenoids, but the solenoids themselves tested fine. The issue wasn’t mechanical; it was the TCM giving faulty commands. We installed one of our pre-programmed modules in under 30 minutes. The codes cleared, the transmission shifted perfectly on the test drive, and the customer saved thousands. It’s a classic case where fixing the brain saves the body.
Is Your TrailBlazer Showing These Transmission Warning Signs?
A faulty 2006 TrailBlazer EXT TCM can manifest in several ways. If you’re noticing any of the following, it’s time for a diagnosis:
- âś” Harsh, banging shifts or a noticeable hesitation between gears.
- âś” The vehicle is stuck in a single gear (often 2nd or 3rd), a condition known as “limp mode.”
- âś” Your Check Engine Light or a dedicated transmission warning light is illuminated.
- âś” Diagnostic Trouble Codes (DTCs) are present, especially a general P0700 or specific solenoid codes like P0751, P0756, etc.
- âś” A sudden drop in fuel economy or the transmission seems to be overheating.
- âś” Complete loss of gear engagement or intermittent communication failure.
Your Straightforward Installation Guide
One of the best features of this module is its simple, DIY-friendly installation. You don’t need a hydraulic lift or specialized transmission tools. Get your 2006 TrailBlazer EXT TCM replaced and your vehicle back to normal in under an hour.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electronic component replacement.
- Locate the Module: On your 2006 TrailBlazer EXT, the TCM is conveniently located in the engine compartment on the left-hand (driver’s) side.
- Swap the Part: Carefully disconnect the wiring harnesses from the old module. Unbolt it from its mounting bracket and set it aside. Bolt the new module in its place and securely reconnect the wiring harnesses.
- Final Steps: Reconnect the negative battery terminal. The system will be reset. It’s a good practice to use a basic OBD2 scan tool to clear any stored transmission codes to ensure a clean slate for the new module.
Verified Fitment for Your Vehicle
This T42 TCM is a direct-fit replacement for a wide range of General Motors vehicles. Please confirm your model and year below. This listing is specifically for the 2006 TrailBlazer EXT TCM with the 8-cylinder engine.
- 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)
- ENVOY 06-09 Transmission; (LH engine compartment)
- EXPRESS & SAVANA VANS 06-14 Transmission; (RH engine compartment)
- HHR 06-11 Transmission; (LH engine compartment)
- HUMMER H3 08-10 Transmission; (RH rear engine compartment)
- IMPALA 06-11 Transmission; (lower air cleaner housing)
- SAAB 9-7X 06-09 Transmission; (LH engine compartment)
- SIERRA & SILVERADO 1500/2500 07-13 Transmission; (next to battery)
- TAHOE & YUKON 07-09 Transmission; (next to battery)
- …and many other GM models from 2006-2014.
Frequently Asked Questions
Do I need to program this module?
No. This is the key benefit. We program the module to your vehicle’s VIN before shipping. It arrives ready for installation, saving you hundreds in dealership programming fees.
Where is the TCM located on my 2006 TrailBlazer EXT?
The Transmission Control Module is located in the engine bay, on the driver’s side (LH) of the engine compartment.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old part or recycle it locally without the hassle of shipping it back.
What kind of warranty is included?
This part is backed by our one-year, hassle-free warranty, giving you peace of mind for your repair.
Will this 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 shorts or failed driver circuits that trigger other codes), you should ensure any related wiring or solenoid issues are checked first. In a vast majority of cases I’ve seen, a new TCM is the final fix.