Restore Smooth Shifting to Your Trailblazer
Is your 2006-2009 Chevrolet Trailblazer suffering from frustrating and unpredictable transmission problems? Issues like harsh shifting, getting stuck in gear, or an illuminated check engine light are often not signs of a failing transmission, but rather a faulty Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless drivers worry about expensive transmission rebuilds when the real culprit was this electronic module. This T42 TCM, part number 24243901, is the direct, reliable solution to restore your vehicle’s performance and your peace of mind.
This isn’t just a replacement part; it’s a complete fix. We pre-program each module to your Trailblazer’s specific Vehicle Identification Number (VIN) before it ships. This critical step ensures that the module communicates flawlessly with your vehicle’s engine computer and other systems right out of the box. You get to skip the costly and time-consuming trip to the dealership for programming, making this an ideal repair for both seasoned mechanics and DIY enthusiasts.
From the Diagnostic Bay: The “Simple” Fix for a Complex Problem
A customer brought in a 2008 Trailblazer with classic symptoms: it would slam into gear from a stop and occasionally refuse to shift past 2nd gear. Another shop had quoted them over $3,000 for a transmission rebuild. I hooked up my scan tool and saw a P0753 code for a Shift Solenoid ‘A’ Electrical fault. While this can point to a bad solenoid, experience told me to check the source. We tested the wiring and found no issues. The problem was the TCM itself; it was failing to properly command the solenoid. We installed a VIN-programmed 2006-2009 Trailblazer TCM, cleared the codes, and the truck shifted like new. It was a $300 fix that saved the customer thousands and got them back on the road safely.
Is Your Trailblazer Showing These Warning Signs?
A failing TCM can manifest in several ways. If you’re experiencing any of the following, this module is the likely solution.
- âś” Harsh, erratic, or delayed gear shifts that make driving uncomfortable.
- âś” Vehicle is stuck in “limp mode,” often locked in 2nd or 3rd gear.
- âś” Check Engine Light or Transmission Warning Light is on.
- âś” Diagnostic Trouble Codes (DTCs) are present, especially P0700 (Transmission Control System Malfunction) or other solenoid-related codes (e.g., P0750, P0753, P0758).
- âś” A sudden drop in fuel economy or a feeling of sluggish performance.
- âś” Complete loss of communication with the transmission, preventing it from shifting at all.
A Straightforward Guide to Your TCM Replacement
Installing your new 2006-2009 Trailblazer TCM is a manageable job for anyone with basic tools. It’s typically located in the engine bay for easy access.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the Module: On most Trailblazer and Envoy models, the TCM is found in the left-hand (driver’s side) engine compartment.
- Disconnect and Remove: Carefully unclip the electrical connectors. Be gentle to avoid damaging the pins or clips. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Reconnect the electrical connectors, ensuring they click securely into place.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s always a good practice to use a basic scan tool to clear any stored fault codes from the vehicle’s memory.
Verified Vehicle Compatibility
This module is a direct replacement for part number 24243901 and interchanges with several other GM service numbers. It is guaranteed to fit the following models, specifically confirming fitment for the 2006-2009 Trailblazer TCM application:
- TRAILBLAZER 06-07 Transmission; (LH engine compartment), (8 cylinder)
- TRAILBLAZER 08-09 Transmission; (LH engine compartment)
- TRAILBLAZER EXT 06 Transmission; (LH engine compartment), (8 cylinder)
- ENVOY 06-07 Transmission; (LH engine compartment), (8 cylinder)
- ENVOY 08-09 Transmission; (LH engine compartment)
- ENVOY XL 06 Transmission; (LH engine compartment), (8 cylinder)
- RAINIER 06-07 Transmission
- SAAB 9-7X 06-09 Transmission; (LH engine compartment)
- …and many other GM cars, trucks, and SUVs listed in the original fitment data.
Do I need to get this TCM programmed by a dealer?
Do I need to get this TCM programmed by a dealer?
No. We handle all the programming for you. Simply provide your vehicle’s VIN during checkout, and the module will arrive ready for plug-and-play installation, saving you time and money.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the main engine computer. In many cases, a failing TCM is the root cause of this code and other related transmission codes. Replacing the module with our programmed unit is a very common and effective fix for this issue.
Where is the TCM located on my 2007 Trailblazer?
For the 2006-2009 Trailblazer, the Transmission Control Module is located in the engine compartment on the driver’s side (LH side), making it relatively easy to access for replacement.
Is there a core charge for my old part?
No, there is no core charge required. You can keep or dispose of your old module without the hassle of returning it, making the repair process simpler and faster.