If your 2006 Chevrolet Trailblazer EXT is suffering from harsh shifts, getting stuck in gear, or throwing transmission codes, you’ve come to the right place. As a technician with over two decades of experience under the hood, I’ve seen countless GM vehicles sidelined by a faulty Transmission Control Module (TCM). This isn’t just an inconvenience; it’s a critical failure that can affect your vehicle’s safety and longevity. This T42 TCM, part number 24235340, is the reliable, straightforward solution you need to get your SUV driving smoothly again.
The biggest headache with replacing electronic modules is the expensive and time-consuming trip to the dealership for programming. We eliminate that step entirely. This module arrives at your door pre-programmed to your vehicle’s specific VIN. That means it’s ready for plug-and-play installation right out of the box, restoring the precise electronic control your 4L60E or 4L65E transmission requires for optimal performance and fuel efficiency.
From the Diagnostic Bay
I remember a customer with a 2006 Trailblazer EXT, the 8-cylinder model, who was at his wit’s end. His truck would shift hard from 1st to 2nd and sometimes refuse to shift past 3rd gear, triggering the check engine light with a generic P0700 code. He’d already replaced a shift solenoid with no change. After connecting my scan tool, I saw communication errors with the TCM. These T42 modules, often mounted in the engine bay, are susceptible to failure from years of heat cycles and vibration. Swapping in a VIN-programmed module like this one resolved all his shifting issues in under an hour, without needing a dealer’s Tech 2 scanner. It’s a common and definitive fix.
Is Your Trailblazer Exhibiting These Transmission Issues?
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ The vehicle is stuck in “limp mode,” usually only allowing access to 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is on with Diagnostic Trouble Codes (DTCs) like P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔ Inability to upshift or downshift properly, leading to poor acceleration.
- ✔ A noticeable drop in fuel economy or signs of the transmission overheating.
- ✔ Complete loss of communication with the transmission module.
Your 30-Minute Path to a Smooth Ride
Installing your new 2006 Trailblazer EXT TCM is a job most DIYers can handle with basic tools. For the Trailblazer, the module is typically located in the left-hand (driver’s side) engine compartment, making it easily accessible.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electronic work. This prevents electrical shorts and helps reset the vehicle’s systems.
- Locate the Old TCM: On your Trailblazer EXT, find the module in the LH engine compartment. It will have several large electrical connectors attached.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that may need to be pressed or slid to release. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely reconnect the wiring harnesses, ensuring they click and lock into position.
- Final Steps: Reconnect the battery terminal. Start the vehicle and let it run for a moment. While the module is plug-and-play, it’s good practice to use a basic OBD2 scanner to clear any stored fault codes from the previous failure.
Verified Compatibility for Your GM Vehicle
This T42 TCM is a direct replacement for part number 24235340 and is interchangeable with a wide range of other service numbers. It is engineered to work with numerous GM vehicles equipped with 4-speed automatic transmissions from approximately 2006 to 2014. While this listing is for the Trailblazer EXT, please verify fitment for other models below:
- Chevrolet: Trailblazer (8-cyl), Trailblazer EXT (8-cyl), Tahoe, Silverado, Express, Impala, Monte Carlo, HHR, Cobalt, Avalanche, Colorado
- GMC: Envoy (8-cyl), Envoy XL (8-cyl), Yukon, Sierra, Savana, Canyon
- Buick: Rainier, LaCrosse, Lucerne, Allure
- Cadillac: DTS
- Pontiac: G6, Grand Prix, Pursuit
- Saturn: Vue, Aura, Ion
- Hummer: H3
- Saab: 9-7X
Frequently Asked Questions
What does VIN programming mean for me?
It means this module is a true plug-and-play solution. We flash it with your vehicle’s specific VIN and the latest GM software before shipping. This ensures it communicates perfectly with your engine and other systems, saving you a trip to the dealership and hundreds in programming fees.
Do I need a professional mechanic to install this TCM?
Not necessarily. If you’re comfortable with basic hand tools and disconnecting a battery, this is a very manageable DIY job. The location in the engine bay is typically easy to access, and the process takes less than an hour.
Will this fix a ‘Service Transmission’ warning on my dash?
In many cases, yes. A failing TCM is one of the most common causes of this warning light, especially when accompanied by the shifting problems listed above. Replacing a faulty module is the direct fix for the issue.
Is there a core charge for my old part?
No, there is no core charge. You are not required to send your old, faulty module back to us, which simplifies the process for you.
What kind of warranty is included?
We stand behind our products. This transmission control module comes with a one-year warranty, giving you peace of mind with your purchase.