Restore Your Trailblazer’s Shifting Performance
If you’re dealing with the headaches of a faulty transmission control module in your 2006-2009 Chevrolet Trailblazer, you know how frustrating it can be. One minute your SUV is driving fine, the next it’s banging into gear, refusing to shift, or throwing a check engine light that puts it into a restrictive limp mode. As a technician with over two decades of experience, I’ve seen countless GM vehicles sidelined by these exact issues. The T42 TCM is the electronic brain of your automatic transmission, and when it fails, it disrupts everything from shift timing to fuel efficiency.
This isn’t just an inconvenience; it’s a reliability issue. You need a solution that works right out of the box. That’s why we offer this high-quality replacement Transmission Control Module, part number 24239224, professionally programmed to your vehicle’s specific VIN. This crucial step ensures that the module communicates flawlessly with your vehicle’s other systems, eliminating the need for an expensive and time-consuming trip to the dealership for programming. It’s the definitive fix for your transmission woes.
From the Diagnostic Bay
I remember a 2008 Trailblazer that came into my shop with a classic complaint: intermittent, harsh 1-2 shifts and occasionally getting stuck in 3rd gear. The owner had already replaced a shift solenoid based on a code, but the problem persisted. After hooking up my scan tool, I saw the tell-tale communication errors and erratic data from the TCM. The internal logic was failing under load. We installed one of these VIN-programmed modules, and the difference was immediate. The shifts were crisp and smooth, and all transmission-related codes were gone for good. This is the kind of straightforward, effective repair that gets you back on the road without the guesswork.
Is Your Trailblazer Exhibiting These Telltale Signs?
A failing TCM can manifest in several ways. If you’re noticing any of the following, it’s a strong indicator that your module needs replacement. Ignoring these symptoms can lead to more significant transmission damage down the line.
- ✔ Harsh, erratic, or delayed gear shifts that make driving uncomfortable.
- ✔ The vehicle is stuck in “limp mode,” often locked in 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is on, with Diagnostic Trouble Codes (DTCs) like P0700, P0750, P0753, or other solenoid-related faults.
- ✔ Complete failure to upshift or downshift, leading to poor acceleration and performance.
- ✔ A noticeable drop in fuel economy as the transmission operates inefficiently.
- ✔ Intermittent loss of communication with the TCM, causing unpredictable behavior.
A Straightforward Guide to Installation
One of the best features of this module is its simple installation, which most DIYers can complete in under 30 minutes with basic hand tools. For the 2006-2009 Trailblazer TCM, you’ll find it located in the left-hand (driver’s side) engine compartment.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electronic component replacement. This prevents electrical shorts and helps reset the vehicle’s systems.
- Locate the TCM: On your Trailblazer, the TCM is typically mounted in the LH engine compartment. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. Press the release tabs firmly to avoid damaging them. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place. Reconnect the wiring harnesses, ensuring they click securely into position.
- Final Steps: Reconnect the negative battery terminal. While our programming handles the critical setup, it’s always a good practice to use a basic OBD2 scan tool to clear any stored fault codes from the vehicle’s memory. Start the engine and enjoy restored, smooth shifting!
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
It means we load your vehicle’s unique 17-digit Vehicle Identification Number (VIN) and the latest GM software onto the module before shipping it. This makes the part a direct, plug-and-play replacement, as it’s already configured to communicate perfectly with your Trailblazer’s engine and other systems, just like an OEM part from the dealer.
Do I need to take my truck to a dealer after installation?
No. Our VIN programming service completely eliminates the need for any additional programming or setup at a dealership, saving you time and money.
Is this compatible with other GM vehicles?
Yes, this T42 TCM is compatible with a wide range of GM vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. Please check the detailed fitment list below to confirm compatibility with your specific make and model.
Is there a core charge for my old part?
No, we do not require a core charge. You can keep your old part, so there’s no need to worry about the hassle and expense of shipping it back.
Verified Vehicle Compatibility
This module is a direct replacement for part number 24239224 and interchanges with several other service numbers. It is guaranteed to fit the following vehicles:
This part will fit these makes and models with these options
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)
SAAB 9-7X 06-09 Transmission; (LH engine compartment)
And many other GM cars, trucks, and SUVs from 2006-2014. Please verify your vehicle in the complete list.