If you’re dealing with a 2007 or 2008 Chevrolet Avalanche that’s shifting erratically, banging into gear, or stuck in limp mode, you’re not alone. These are classic symptoms of a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless GM trucks sidelined by this exact issue. The TCM is the brain of your automatic transmission, and when it starts to fail, it can cause a host of frustrating and potentially damaging problems. This VIN-programmed T42 TCM is the direct, reliable solution to get your truck back to shifting smoothly and dependably.
This isn’t just a replacement part; it’s a complete fix. We handle the most critical step for you: programming. Before this module ships, we flash it with the latest GM software updates and calibrate it specifically to your truck’s Vehicle Identification Number (VIN). This means you can skip the expensive trip to the dealership for programming. It arrives at your door ready for a true plug-and-play installation, saving you time, money, and hassle.
Is Your Avalanche Exhibiting These Telltale Signs?
A faulty TCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement:
- ✔ Harsh, delayed, or unpredictable gear shifts.
- ✔ The transmission refuses to shift up or down, or gets stuck in one gear (often 2nd or 3rd).
- ✔ Your Check Engine Light or a transmission-specific warning light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, especially P0700 (Transmission Control System Malfunction) or various solenoid-related codes (e.g., P0750-P0758).
- ✔ A sudden drop in fuel efficiency or signs of the transmission overheating.
- ✔ Complete loss of communication with the TCM, leading to a no-start or no-shift condition.
Case Study: The Ghost in the Transmission
A customer brought in his ’08 Avalanche 1500 with a perplexing issue. He said it would drive perfectly for days, then suddenly start slamming into gear and get stuck in 3rd. He’d already replaced two shift solenoids at another shop with no success. After hooking up my scan tool, I noticed intermittent communication drops with the TCM. Heat soak in the engine bay was causing an internal fault in the module to surface. We installed one of our pre-programmed T42 TCMs, and the problem was solved instantly. It wasn’t a mechanical issue at all, but an electronic one—a common scenario with these vehicles.
A Straightforward Guide to Installation
One of the best parts about this fix is how accessible it is for a DIY mechanic. For the 2007-2008 Avalanche TCM, the module is conveniently located right next to the battery in the engine compartment. You can complete this job in under 30 minutes with basic hand tools.
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts and to help reset the system.
- Locate the TCM: Open the hood and find the TCM mounted next to the battery. It’s a silver box with several large electrical connectors.
- Disconnect and Remove: Carefully unclip the wiring harness connectors. Then, unbolt the module from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely reconnect the wiring harnesses, ensuring they click into place.
- Final Steps: Reconnect the negative 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 DTCs from the system’s memory.
Verified Vehicle Compatibility
This module, part number 24235732, is a direct replacement for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. It interchanges with numerous service numbers, including 24252114, 24234503, and 24240449. While it is a guaranteed fit for the specified Avalanche, it also fits the following models:
- ✔ AVALANCHE 1500 (2007-2008) – Location: (next to battery)
- ✔ Chevrolet Silverado & GMC Sierra 1500/2500 (2007-2013)
- ✔ Chevrolet Tahoe & GMC Yukon / Yukon XL (2007-2009)
- ✔ Chevrolet Suburban 1500 (2007-2008)
- ✔ Chevrolet Express & GMC Savana Vans (2006-2014)
- ✔ Hummer H3 (2008-2010)
- ✔ Cadillac DTS (2006-2011)
- ✔ Buick LaCrosse / Allure / Lucerne (2006-2011)
- ✔ And many other GM cars, trucks, and SUVs from 2006-2014. Please verify your specific model in the detailed list.