Is your 2008-2010 Hummer H3 suffering from frustrating and unpredictable transmission behavior? Hard shifts, getting stuck in gear, or an illuminated check engine light can ruin your driving confidence, whether you’re on the highway or a trail. As the transmission’s brain, a failing Transmission Control Module (TCM) is often the culprit. This VIN-programmed T42 TCM, corresponding to part number 24256960, is the definitive solution to restore the crisp, reliable shifting your H3 was built for.
Forget about expensive dealership visits and the hassle of programming. We handle it for you. Simply provide your vehicle’s VIN at checkout, and we’ll flash the module with the latest GM software specific to your Hummer. This ensures it works perfectly right out of the box, resolving common communication and performance issues that plague these vehicles.
Case Study: A Tricky Diagnosis
A customer brought in their ’09 H3, stuck in limp mode (3rd gear only) with a P0700 code. They were worried about a full transmission rebuild, which can cost thousands. In my shop, I’ve seen this exact scenario dozens of times. Before condemning the transmission, we checked the TCM. These T42 modules, located in the engine bay, are susceptible to heat and vibration, which can cause internal circuit failure. After swapping in a pre-programmed module, the codes cleared, and the H3 was shifting perfectly in under an hour. It’s a classic case where the fix is much simpler and more affordable than it first appears.
Is Your H3 Showing These Telltale Signs?
A faulty TCM can manifest in several ways. If you’re experiencing any of the following, this module is the likely solution for your 2008-2010 Hummer H3 TCM issues:
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ Vehicle is stuck in one gear (often called “limp mode”).
- ✔ Check Engine Light is on with transmission-specific Diagnostic Trouble Codes (DTCs) like P0700, P0750, or other solenoid-related faults.
- ✔ Inability to upshift or downshift, leading to poor acceleration.
- ✔ A sudden drop in fuel economy.
- ✔ Complete loss of communication with the transmission.
A Straightforward Guide to Installation
You don’t need to be a master mechanic to replace this part. The process is simple and can be completed in your driveway with basic tools.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the system.
- Locate the Module: On the Hummer H3, the TCM is typically found in the engine compartment on the right-hand (passenger) side, towards the rear.
- Disconnect and Remove: Carefully unclip the electrical connectors. Then, unbolt the old module from its mounting bracket.
- Install the New TCM: Mount your new, VIN-programmed module in place, securely re-fasten the bolts, and plug in the electrical connectors until they click.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s good practice to use a basic scan tool to clear any stored fault codes from the vehicle’s memory.
Verified Vehicle Compatibility
This T42 Transmission Control Module is a direct-fit replacement for part number 24256960 and other interchangeable numbers. While it fits a wide range of GM vehicles, it is guaranteed to be the correct part for the following:
- HUMMER H3: 2008, 2009, 2010 (Transmission; RH rear engine compartment)
- Chevrolet Colorado: 2008-2012
- GMC Canyon: 2008-2012
- And many other GM cars, trucks, and SUVs from 2006-2014. Please verify your part number for a perfect match.
By choosing this pre-programmed 2008-2010 Hummer H3 TCM, you are not just buying a part; you are buying a permanent solution that restores your vehicle’s performance and your peace of mind. Get back to confident driving without the dealership price tag.
Frequently Asked Questions
What does “VIN Programmed” mean?
It means we load your vehicle’s unique Vehicle Identification Number (VIN) and the latest GM software onto the module before shipping. This makes it a true plug-and-play part, as it’s already configured to communicate perfectly with your H3’s engine and other systems, eliminating the need for a trip to the dealer for expensive programming.
Is this a difficult part to install myself?
Not at all. For a DIY enthusiast with basic tools, this is a very straightforward job that typically takes less than 30 minutes. The module is easily accessible in the engine bay, and no special procedures are required.
How can I be sure the TCM is the problem?
Common symptoms like being stuck in gear, harsh shifting, and specific transmission codes (P0700 series) are strong indicators of TCM failure. While a professional diagnosis is always best, these symptoms are classic signs that the electronic module, not the mechanical parts of the transmission, has failed.
Do I need to send my old part back?
No, there is no core charge for this module. You can keep your old part, which saves you the time and expense of return shipping.
What kind of warranty is included?
This module comes with a one-year warranty, giving you confidence and peace of mind in your repair. We stand behind the quality and reliability of our parts.