Restore Flawless Shifting to Your HUMMER H3
If your 2008-2010 HUMMER H3 is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, you’ve come to the right place. As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Transmission Control Module (TCM) can sideline a perfectly good vehicle. This T42 series TCM, part number 24235754, is the definitive solution to restore the crisp, predictable performance of your H3’s automatic transmission.
The TCM is the brain of your transmission, constantly managing shift points, torque converter lockup, and fluid pressure. When it fails, the symptoms can range from annoying to dangerous. This replacement module is meticulously prepared and programmed to your vehicle’s specific VIN, ensuring it works perfectly right out of the box, with no need for an expensive trip to the dealership for programming.
From the Diagnostic Bay: The Intermittent H3 Nightmare
I remember a customer bringing in his 2009 H3 with a complaint that stumped two other shops. The truck would occasionally refuse to shift out of 2nd gear, but only after it was fully warmed up. Of course, it never acted up for us initially. We pulled a generic P0700 (Transmission Control System Malfunction) code, but no specific solenoid codes. After checking wiring and fluid, we suspected the TCM. These modules can develop internal heat-related failures that don’t always set a hard fault. We swapped in a VIN-programmed module like this one, and the problem was solved instantly. The customer was thrilled to have his reliable off-roader back without a costly diagnostic chase.
Common Signs of a Failing HUMMER H3 TCM
A faulty TCM can manifest in several ways. If you’re experiencing any of the following, this module is your likely solution.
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ The Check Engine Light is on with codes like P0700, P0750-P0758 (solenoid circuits), or other transmission-related DTCs.
- ✔ Complete failure to shift up or down.
- ✔ A noticeable drop in fuel economy.
- ✔ Intermittent loss of communication with the TCM, causing unpredictable behavior.
Why Our 2008-2010 HUMMER H3 TCM is the Smart Solution
This isn’t just a replacement part; it’s a complete repair solution. The most critical feature is our complimentary VIN programming. When you order, we flash the module with the latest GM software calibrated specifically for your H3. This eliminates communication errors and ensures the transmission operates exactly as the manufacturer intended, adapting to your specific vehicle’s parameters for optimal shift quality and longevity.
Your 30-Minute Path to a Smooth Ride
For the confident DIYer or professional mechanic, installation is a straightforward process that requires basic hand tools and can be completed in under 30 minutes.
- 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 2008-2010 HUMMER H3, the TCM is located in the engine compartment on the right-hand (passenger side) rear area.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly. 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. You should hear a click as they lock in.
- Reconnect and Verify: Reconnect the battery terminal. Start the vehicle and check for any warning lights. It’s good practice to use a basic OBD2 scanner to clear any stored fault codes after the repair.
Verified Vehicle Compatibility
This module is a direct-fit, programmed solution for the following vehicle:
- HUMMER H3: 2008, 2009, 2010 (Transmission; RH rear engine compartment)
This T42 TCM is also interchangeable with multiple part numbers and fits a wide array of other GM vehicles, including the Chevrolet Colorado, GMC Canyon, and various vans and SUVs. Part numbers include: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, and more.
Frequently Asked Questions
What exactly is VIN programming and why do I need it?
VIN programming involves loading your vehicle’s unique 17-digit Vehicle Identification Number and its corresponding factory software onto the module. This ensures the TCM communicates correctly with your H3’s engine computer and other systems for proper shifting, fuel economy, and performance. Without it, the module won’t work.
Do I need to take this part to a dealer after I install it?
No. Because we program the module to your VIN before shipping, it is a true plug-and-play solution. This saves you the time and expense (often $150+) of a dealership programming service.
Is this a difficult part to install myself?
For most people with basic mechanical skills, this is an easy installation. It’s located in an accessible part of the engine bay and only requires simple hand tools to unbolt and unplug. Our step-by-step guide makes it even easier.
Is there a core charge for my old TCM?
No, there is no core charge. You can keep your old part or dispose of it at your convenience without the hassle of returning it.
What kind of warranty is included?
This module comes with a one-year, no-hassle warranty, giving you peace of mind and confidence in your repair.