Restore Your Trailblazer’s Shifting Performance
If your 2006-2009 Chevrolet Trailblazer is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, you’re not alone. After 20 years in the business, I’ve seen countless GM vehicles with these exact issues, and the culprit is almost always a failing Transmission Control Module (TCM). This T42 module, part number 24235732, is the definitive solution to restore the crisp, reliable shifting you expect from your SUV. It’s not just a part; it’s a permanent fix that gets you back on the road with confidence.
The core of the problem often lies in the original module’s internal electronics breaking down from heat and vibration over time. This leads to miscommunication between the engine and transmission, causing the frustrating symptoms you’re experiencing. Our solution is a high-quality replacement T42 module that comes pre-programmed to your Trailblazer’s specific Vehicle Identification Number (VIN). This means no expensive trips to the dealership for programming—it’s a true plug-and-play repair you can do right in your driveway.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 Trailblazer with a classic complaint: it would randomly refuse to shift out of 2nd gear and the check engine light was on. His local shop had already replaced two shift solenoids, but the problem persisted. Scanning the vehicle, I found a generic P0700 (Transmission Control System Malfunction) code. Instead of just throwing more parts at it, we looked at the live data. The TCM was intermittently losing communication. This is a tell-tale sign of internal module failure, not a mechanical issue. We installed one of our VIN-programmed T42 modules. The total repair time was under 25 minutes. After a test drive, the shifting was perfect, and the codes never returned. It saved the customer hundreds in wasted labor and parts.
Is Your Trailblazer Showing These Transmission Issues?
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ The Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0755, or other solenoid-related faults.
- ✔ Inconsistent shifting, flaring between gears, or a complete loss of forward or reverse gears.
- ✔ A noticeable drop in fuel economy due to inefficient transmission operation.
A Straightforward Guide to Installation
Replacing the 2006-2009 Trailblazer TCM is a simple job that most DIYers can complete in under 30 minutes with basic hand tools. This module is located in the engine compartment on the driver’s side (LH side).
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: Find the TCM in the engine bay. On the Trailblazer, it’s typically mounted on the LH side.
- Disconnect and Remove: Carefully unplug the electrical connectors. Be gentle with the locking tabs. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place and securely reconnect the electrical harnesses. You should hear a ‘click’ as they lock.
- Final Steps: Reconnect the battery terminal. Start the vehicle and let it idle for a few minutes. While our programming clears most faults, it’s good practice to use a basic scan tool to clear any remaining stored codes.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24235732 and other interchangeable numbers. While this page focuses on the Trailblazer, it is also confirmed to fit the following vehicles. Always verify your part number for a perfect match.
- Chevrolet Trailblazer: 2006-2007 (8 cylinder), 2008-2009 (All) – Located in LH engine compartment.
- GMC Envoy / Envoy XL: 2006-2007 (8 cylinder), 2008-2009 (All) – Located in LH engine compartment.
- Chevrolet SSR: 2005-2006 – Located on front LH frame.
- Hummer H3: 2008-2010 – Located in RH rear engine compartment.
- Saab 9-7X: 2006-2009 – Located in LH engine compartment.
- …and many other GM cars, trucks, and SUVs from 2006-2014. Please check the full fitment list or contact us with your VIN.
Frequently Asked Questions
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean for me?
It means we load your vehicle’s unique 17-digit VIN into the module before we ship it. This ensures the TCM has the correct software and settings for your Trailblazer’s specific transmission and options, making it a true plug-and-play part. You will not need to pay a dealership for programming.