If you’re dealing with the headaches of a faulty transmission in your 2007-2008 Chevrolet Avalanche, you know how frustrating it can be. One minute it’s fine, the next you’re getting harsh, clunky shifts, or worse—the truck is stuck in limp mode. As a technician with over two decades of experience, I’ve seen this scenario countless times. The culprit is often a failing Transmission Control Module (TCM), the electronic brain that dictates every shift. This T42 TCM, part number 24252114, is the definitive solution, arriving pre-programmed to your truck’s specific VIN for a true plug-and-play repair.
Forget about expensive tow bills and dealership programming fees. We handle the complex part for you. By programming the module with the latest GM software updates before it ships, we ensure it communicates flawlessly with your vehicle’s systems right out of the box. This restores the crisp, predictable shifting performance your Avalanche had from the factory, improves fuel economy, and eliminates those persistent transmission-related warning lights on your dash.
Case Study: A Tricky Diagnosis
A customer brought in his ’07 Avalanche 1500 with a complaint that stumped two other shops: intermittent, violent 1-2 shifts and occasional failure to shift out of 2nd gear, but with no consistent codes other than a general P0700. We checked the fluid, solenoids, and wiring harness—all looked good. Based on my experience with these 4L60E/4L70E transmissions, I suspected the T42 module was failing internally, likely due to heat cycles and vibration. We installed one of our VIN-programmed modules, and the problem vanished instantly. The customer was back on the road in under an hour, saving him from what could have been a costly and unnecessary transmission rebuild.
Is Your Avalanche Exhibiting These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission failure. Often, it presents as a series of electronic gremlins. Here’s what to look for:
- âś” Abrupt, harsh, or delayed gear shifts that make driving uncomfortable.
- âś” The vehicle suddenly entering “limp mode,” typically stuck in 2nd or 3rd gear.
- âś” Check Engine Light or Transmission Warning Light illuminated with codes like P0700 (Transmission Control System Malfunction), P0750-P0758 (Shift Solenoid errors), or other communication faults.
- âś” Inability to upshift or downshift, leading to poor acceleration and high RPMs.
- âś” A noticeable drop in fuel efficiency as the transmission operates inefficiently.
- âś” Complete loss of communication with the TCM, preventing the vehicle from starting or shifting out of Park.
Solving the Problem with a Programmed 2007-2008 Avalanche 1500 TCM
This isn’t just a replacement part; it’s a complete repair solution. The core benefit is the VIN-specific programming. Modern vehicles have complex networks, and a new module needs to be introduced and configured to work with the Engine Control Module (ECM) and other systems. Our process eliminates that step, making it a feasible job for a DIY enthusiast or a quick swap for a professional mechanic. Built to meet or exceed OEM specifications, this module is your most reliable path to restoring your truck’s performance and your peace of mind.
DIY-Friendly Installation in Under 30 Minutes
For the 2007-2008 Avalanche 1500, the TCM is conveniently located in the engine bay, making for a straightforward swap. You don’t need a vehicle lift or specialized transmission tools.
- Safety First: Always disconnect the negative terminal on your truck’s battery to prevent any electrical shorts and to help reset the vehicle’s electronic systems.
- Locate the Module: On your Avalanche, the TCM is typically mounted next to the battery in the engine compartment. It’s a silver box with large electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical connectors. There may be locking tabs you need to release. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely plug in the electrical connectors until they click, ensuring a solid connection.
- Final Steps: Reconnect the negative battery terminal. While our programming resolves most codes, it’s good practice to use a basic OBD2 scan tool to clear any stored diagnostic trouble codes (DTCs) from the vehicle’s memory. Start the truck and enjoy smooth shifting!
Verified Fitment for Your GM Truck or SUV
This T42 TCM is a direct replacement for part number 24252114 and is compatible with a wide range of GM vehicles equipped with 4-speed automatic transmissions (like the 4L60E, 4L65E, and 4L70E). While this page is focused on the 2007-2008 Avalanche 1500 TCM, it also fits the following models (please verify location notes):
- AVALANCHE 1500 07-08 Transmission; (next to battery)
- CHEVROLET SILVERADO & GMC SIERRA 1500/2500 07-13 (New Style); (next to battery)
- CHEVROLET TAHOE & GMC YUKON / YUKON XL 07-09 (next to battery)
- CHEVROLET SUBURBAN 1500 07-08 (next to battery)
- CHEVROLET EXPRESS & GMC SAVANA VANS 06-14 (RH engine compartment)
- HUMMER H3 08-10 (RH rear engine compartment)
- CADILLAC DTS 06-11 (RH front engine compartment)
- …and many other Buick, Chevrolet, GMC, Pontiac, and Saturn models. Refer to the full fitment list for details.
Frequently Asked Questions
Do I need to take my truck to the dealership after installation?
No. This Transmission Control Module comes fully programmed to your vehicle’s VIN. The service eliminates the need for any additional programming or setup at a dealership, saving you time and money.
Is this a difficult part to install myself?
For most DIYers with basic hand tools, this is a very manageable job. On the 2007-2008 Avalanche, the TCM is easily accessible in the engine bay next to the battery. The entire process typically takes less than 30 minutes.
What part number does this module replace?
This module, 24252114, is a direct replacement for numerous GM service numbers, including 24242391, 24234503, 24256960, and others. It is designed to be fully interchangeable.
Will this fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. If the root cause is a faulty module, replacing it with this programmed unit will resolve the issue and allow the code to be cleared permanently.
Is there a core charge for my old part?
No, we do not require a core return. You can keep your old module without any extra charges or hassle.