Regain Control of Your Hummer’s Transmission
Is your 2008-2010 Hummer H3 suffering from frustrating and unpredictable transmission behavior? If you’re dealing with harsh bangs into gear, a refusal to shift, or a check engine light that points to transmission trouble, a failing Transmission Control Module (TCM) is the most likely culprit. As the electronic brain of your automatic transmission, the TCM’s health is critical for smooth, reliable performance on and off the road. This OEM-quality T42 TCM, part number 24243901, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play repair.
From the Diagnostic Bay: The Intermittent H3 Shifting Mystery
I remember a 2009 H3 that came into my shop with a problem that was driving the owner crazy. It would drive perfectly for days, then suddenly start slamming into gear or get stuck in 3rd (limp mode). He’d already replaced a couple of solenoids with no luck. After connecting my scan tool, I saw a history of intermittent communication loss codes with the TCM. Heat soak from the engine compartment was causing the delicate internal circuits of the original module to fail unpredictably. Installing a new, VIN-programmed 2008-2010 Hummer H3 TCM didn’t just fix the problem—it provided a stable, reliable solution that restored the owner’s confidence in his vehicle. This is a classic failure I’ve seen countless times on these GM platforms.
Is Your Hummer H3 Showing These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission failure. Often, the signs are electronic and can be mistaken for internal mechanical issues. Watch out for these common symptoms:
- âś” Abrupt, harsh, or delayed gear shifts.
- âś” The vehicle is stuck in a single gear (often called “limp mode”).
- âś” Check Engine Light or Transmission Warning Light is illuminated.
- âś” Diagnostic Trouble Codes (DTCs) are present, such as the general P0700 or specific solenoid codes like P0751, P0756, etc.
- âś” A noticeable decrease in fuel economy.
- âś” The transmission seems to slip out of gear.
- âś” Complete loss of communication with the module, preventing shifting.
Your Straightforward 30-Minute Installation Guide
One of the best features of this part is its simple installation, which saves you a costly trip to the dealership. For the Hummer H3, you can get this done in your own driveway in under half an hour.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the Module: On the 2008-2010 Hummer H3, the TCM is located in the engine compartment on the right-hand (passenger) side, towards the rear.
- Disconnect and Remove: Carefully unclip the electrical connectors from the old TCM. Then, unbolt the module from its mounting bracket.
- Install the New Module: Mount the new, pre-programmed TCM onto the bracket and securely re-attach the electrical connectors. You’ll hear a click when they are seated properly.
- Final Steps: Reconnect the battery terminal. While our programming handles the critical setup, it’s good practice to use a basic scan tool to clear any stored fault codes from the ECU. Start the vehicle and enjoy your restored transmission performance!
Why a Programmed 2008-2010 Hummer H3 TCM is the Best Solution
This isn’t just a replacement part; it’s a complete repair solution. Because we program the module to your vehicle’s VIN before shipping, it learns all the specific parameters of your H3’s 4L60E or 4L65E transmission. This ensures perfect communication between the engine and transmission for optimal shift points, torque converter lockup, and fuel efficiency right out of the box. You get a reliable, long-lasting fix without the added expense or hassle of dealership programming.
Verified Fitment For These GM Models
While this page focuses on the Hummer H3, this T42 TCM is a direct replacement for a wide range of General Motors vehicles from 2006-2014. It is interchangeable with part numbers 24252114, 24234503, 24243921, and more. Common compatible vehicles include:
- âś” Chevrolet Silverado, Tahoe, Suburban, Colorado, Impala, Cobalt, HHR
- âś” GMC Sierra, Yukon, Canyon, Savana
- âś” Cadillac DTS
- âś” Buick LaCrosse, Lucerne
- âś” Pontiac G6, Grand Prix
- âś” Saturn Vue, Aura, Ion
- âś” Saab 9-7X
Frequently Asked Questions
What does ‘VIN Programmed’ mean for me?
It means this module is ready for installation the moment you receive it. We flash it with your Hummer’s specific Vehicle Identification Number (VIN) and the latest GM software, so it works perfectly with your vehicle’s systems without requiring any additional, expensive programming from a dealer.
Do I need any special tools for this job?
No. Basic hand tools, like a socket set to remove the mounting bolts and disconnect the battery, are all that’s required. The entire process is designed to be straightforward for a DIY mechanic.
Is there a core charge?
Absolutely not. You are not required to send your old, faulty module back to us. This saves you the hassle and cost of return shipping.
What if this doesn’t fix my problem?
While this TCM resolves the most common transmission issues, we stand by our products. This part comes with a one-year warranty. If you continue to have issues, our expert support team can help you with further diagnostics.
Will this fix a P0700 trouble code?
Yes, very likely. A P0700 code is a general fault code indicating the TCM has detected a problem. Replacing a faulty TCM is often the correct fix to clear this code and any related, more specific transmission codes.