If your 2007-2008 Chevrolet Avalanche 1500 is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, the culprit is very likely a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless GM trucks and SUVs sidelined by this exact issue. The T42 TCM is the electronic brain of your automatic transmission, and when it fails, it can mimic a catastrophic mechanical failure, leading to costly misdiagnoses. This replacement T42 TCM, part number 24235754, is the definitive solution to restore your truck’s performance and reliability.
We take the guesswork and dealership hassle out of the repair. Before this module ships, we program it directly to your Avalanche’s Vehicle Identification Number (VIN). This ensures it arrives with the latest GM software updates and is ready for a true plug-and-play installation. You won’t need an expensive trip to the dealer for programming—simply install the module, and your truck’s transmission will once again have the precise, factory-intended control over shift points, torque converter lockup, and line pressure.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 Avalanche 1500 with a complaint of intermittent, harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode), especially after driving for 20+ minutes. His local shop quoted him for a full transmission rebuild. He had a P0700 (Transmission Control System Malfunction) code stored. After a quick data scan, I noticed the TCM was intermittently losing communication. Instead of a costly mechanical teardown, we swapped in a VIN-programmed T42 module. The total repair time was under an hour, saving the customer thousands of dollars and solving all the shifting problems. This highlights how a faulty module can easily be mistaken for a much larger issue.
Is Your Avalanche Exhibiting These Telltale Signs?
A failing TCM will give you clear warnings. If you’re experiencing any of the following, it’s time to consider a replacement 2007-2008 Avalanche 1500 TCM:
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ The vehicle is stuck in a single gear (often called “limp mode”).
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750-P0758 (solenoid circuit faults), or U-codes for lost communication.
- ✔ Inconsistent upshifting or downshifting, leading to poor acceleration.
- ✔ A noticeable decrease in fuel economy due to inefficient shifting.
- ✔ Complete loss of communication with the transmission module.
A Straightforward Guide to Installation
Replacing the TCM on your Avalanche is a job most DIYers can handle in their own driveway in about 30 minutes. The module is 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 and to help reset the system.
- Locate the Module: On the 2007-2008 Avalanche, the TCM is usually mounted next to the battery in the engine compartment.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses. Ensure they click into place.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s best practice to use a basic OBD2 scan tool to clear any lingering fault codes from the vehicle’s memory. Start the engine and test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 Transmission Control Module is a direct fit for the 2007-2008 Avalanche 1500 TCM and also interchanges with a wide range of other GM vehicles and part numbers, including 24252114, 24234503, 24235754, and more. It is designed for vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. Below is a partial list of compatible models. Always verify the part number or consult with us to ensure a perfect fit.
- Chevrolet Avalanche 1500 (2007-2008) – Located next to battery
- Chevrolet Silverado & GMC Sierra 1500/2500 (2007-2013)
- Chevrolet Tahoe & GMC Yukon / Yukon XL (2007-2009)
- Chevrolet Express & GMC Savana Vans (2006-2014)
- Cadillac DTS, Buick Lucerne, Hummer H3, and many more.
Do I need to take my truck to the dealer after installing this TCM?
Do I need to take my truck to the dealer after installing this TCM?
No. This module is fully pre-programmed to your vehicle’s VIN before it is shipped. This eliminates the need for any additional programming or setup at a dealership, making it a true plug-and-play solution.
Is this a new or used part?
This is a high-quality, OEM-standard replacement part that has been expertly tested and programmed. It is guaranteed to restore your vehicle’s functionality and is backed by our one-year warranty.
What if my transmission is still shifting poorly after installation?
While this TCM resolves the most common electronic causes of shifting issues, poor performance could also indicate an underlying mechanical problem within the transmission (e.g., worn clutches, faulty solenoids, or low fluid). We recommend having a professional mechanic inspect the transmission’s mechanical condition if problems persist.
Do I need to return my old TCM?
No, there is no core charge for this part. You can keep or dispose of your old module without any hassle or extra fees.