Get Your Hummer H3 Back on the Trail with a Reliable Transmission Fix
As a mechanic with two decades of experience under the hood, I know how frustrating it is when a tough vehicle like your 2008-2010 Hummer H3 starts acting up. Erratic shifting, getting stuck in gear, or a glaring check engine light can ruin your confidence on and off the road. The transmission control module, or TCM, is the brain of your automatic transmission, and when it fails, it can cause a host of problems that seem much bigger than they are. This T42 Transmission Control Module, part number 24256960, is the definitive solution to restore your H3’s smooth, decisive shifting and dependable performance.
The biggest headache with replacing electronic modules is usually the trip to the dealership for expensive programming. We eliminate that step completely. By providing your vehicle’s VIN at checkout, we program the module specifically for your Hummer. It arrives at your door ready for a true plug-and-play installation, saving you time, money, and hassle. This isn’t just a part; it’s a complete, ready-to-install solution for the core electronic issues plaguing your transmission.
Case Study: A Tricky Diagnosis
I remember a 2009 H3 that came into my shop stuck in limp mode (3rd gear only) with a P0700 code. The owner had already replaced two shift solenoids based on a generic code reader’s suggestion, with no change. After a quick diagnostic check, I saw erratic voltage readings coming from the TCM. Instead of a costly transmission teardown, we installed a VIN-programmed T42 module. In under an hour, the truck was shifting perfectly, and the codes were gone for good. It’s a classic case where targeting the brain, not just the symptoms, provides the correct and most efficient repair.
Is Your H3 Showing These Transmission Red Flags?
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ Vehicle is stuck in one gear (often called “limp mode”).
- ✔ Check Engine Light is on with transmission-related Diagnostic Trouble Codes (DTCs) like P0700, P0750, P0755, or other solenoid circuit faults.
- ✔ Inability to upshift or downshift, leading to poor acceleration.
- ✔ A noticeable drop in fuel economy.
- ✔ The transmission seems to slip out of gear unexpectedly.
Your 30-Minute Path to a Smooth-Shifting H3
- ✔ Safety First: Before you begin, disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and help reset the system.
- ✔ Locate the Module: On the 2008-2010 Hummer H3, the TCM is typically found in the engine compartment, on the right-hand (passenger) side towards the rear.
- ✔ 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 your new, pre-programmed TCM into place. Firmly reconnect the electrical connectors, ensuring they click into place.
- ✔ Final Steps: Reconnect the battery terminal. Start the vehicle and use a standard OBD2 scan tool to clear any stored fault codes from the computer’s memory. Your H3 is now ready for a test drive!
Verified Vehicle Compatibility
While this is the direct-fit, programmed solution for your 2008-2010 HUMMER H3, this T42 module is also compatible with a wide range of other GM vehicles. Please verify the part number 24256960 or one of its interchanges (24252114, 24234503, etc.) matches your existing unit. It fits models including:
- HUMMER H3: 2008-2010 (RH rear engine compartment)
- Chevrolet Colorado / GMC Canyon: 2008-2012 (RH rear engine compartment)
- Chevrolet Silverado / GMC Sierra 1500/2500: 2007-2013 (Location varies, often next to battery)
- Chevrolet Tahoe / GMC Yukon: 2007-2009 (Next to battery)
- Chevrolet Express / GMC Savana Vans: 2006-2014 (RH engine compartment)
- Pontiac G6, Cobalt, HHR, and many more. Please confirm your specific model and year.
Frequently Asked Questions
Does this module really not require any extra programming?
That’s correct. We handle all the programming based on your VIN before we ship it. This makes the installation a simple plug-and-play process, with no need for a trip to a mechanic or dealer for software flashing.
What tools do I need for installation?
For most vehicles, including the Hummer H3, you’ll only need basic hand tools like a socket set to unbolt the module and disconnect the battery. A scan tool is recommended to clear codes after installation, but not required for the module to function.
Is there a core charge? Do I need to send my old part back?
No, there is absolutely no core charge. You can keep your old module or dispose of it yourself, making the process hassle-free.
What happens if I don’t provide a VIN?
Providing your VIN is crucial for us to program the module correctly for your vehicle’s specific configuration. An order without a VIN cannot be processed, as the module would not function correctly without this vehicle-specific software.
What kind of warranty is included?
This module is backed by our standard one-year warranty, covering any defects in materials or workmanship for your peace of mind.