Restore Peak Transmission Performance in Your Hummer H3
Is your 2008, 2009, or 2010 Hummer H3 suffering from frustrating transmission problems? Symptoms like harsh, delayed shifting, getting stuck in one gear (limp mode), or an illuminated check engine light can point directly to a failing Transmission Control Module (TCM). The TCM is the electronic brain of your automatic transmission, responsible for orchestrating every gear change and ensuring smooth, efficient operation. When it fails, it can make your rugged H3 feel unpredictable and unreliable. This genuine GM T42 Transmission Control Module, service part 24239224, is the definitive solution to restore your vehicle’s factory performance.
From the Diagnostic Bay
We had a 2009 Hummer H3 come into the shop that was giving the owner fits. It would shift perfectly for a few miles and then suddenly slam into gear or refuse to shift out of 2nd. The owner had already replaced a couple of solenoids with no luck. After hooking up our diagnostic scanner, we saw intermittent communication loss with the TCM and a generic P0700 code. Instead of chasing electrical gremlins for hours, we recommended this VIN-programmed module. Once installed, the communication was stable, the codes were cleared, and the H3 shifted like it just rolled off the assembly line. It’s a common failure point, and a pre-programmed module is the fastest, most reliable fix.
Common Symptoms of a Failing Hummer H3 TCM
A faulty TCM can manifest in various ways. If you’re experiencing any of the following issues, it’s highly likely your transmission module needs replacement:
- ✔ Erratic and Harsh Shifting: Your transmission may bang into gear, hesitate between shifts, or feel generally unpredictable.
- ✔ Stuck in Limp Mode: The vehicle may refuse to shift past 2nd or 3rd gear as a protective measure, severely limiting your speed.
- ✔ Check Engine and Transmission Lights: Often, a failing TCM will trigger the check engine light with codes like P0700 (Transmission Control System Malfunction) or other solenoid-specific codes.
- ✔ Delayed Engagement: When shifting from Park to Drive or Reverse, you might notice a significant delay before the gear engages.
- ✔ Poor Fuel Economy: Inefficient shifting and torque converter lock-up control caused by a bad TCM can lead to a noticeable drop in your MPG.
- ✔ Complete Loss of Shifting: In severe cases, the transmission may not shift at all, leaving you stranded.
Why Our Programmed 2008-2010 Hummer H3 TCM is the Superior Choice
Don’t settle for a generic part that requires expensive dealership visits. Our T42 TCM is meticulously prepared for your specific vehicle, offering benefits you won’t find elsewhere.
Plug-and-Play Installation: The number one benefit is our complimentary VIN programming service. We flash the module with your Hummer H3’s exact Vehicle Identification Number and the latest GM software updates before it ships. This means no additional programming or calibration is needed. It arrives ready to install, saving you time, money, and the hassle of a trip to the dealer.
OEM-Standard Reliability: This module is built to meet or exceed original equipment manufacturer standards. It ensures precise control over shift points, line pressure, and torque converter clutch operation, restoring the smooth and responsive feel your vehicle had when new. It’s engineered for durability to handle both daily driving and off-road adventures.
Hassle-Free Process: We make the repair process as simple as possible. There is no core charge, so you don’t have to worry about the cost or logistics of sending your old, faulty part back to us. Your purchase is also backed by a comprehensive one-year warranty for complete peace of mind.
Easy Installation Guide
Replacing the TCM on your Hummer H3 is a straightforward job that can typically be completed in under 30 minutes with basic hand tools. The module is located in the engine compartment, on the right-hand rear side.
- Safety First: Always disconnect the negative terminal of your vehicle’s battery before starting any electrical work.
- Locate the TCM: Find the module on the RH rear side of the engine bay.
- Disconnect and Remove: Carefully unplug the electrical connectors. Be gentle with the locking tabs. 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.
- Final Steps: Reconnect the battery. While the module is plug-and-play, it’s always a good practice to use a scan tool to clear any stored Diagnostic Trouble Codes (DTCs) from the vehicle’s memory.
Broad Compatibility
This T42 TCM is a direct replacement for a wide range of GM vehicles and interchanges with numerous part numbers, including: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, 24239926, 24240400, 24241806, 24256960, and more. It is the perfect fit for your 2008-2010 Hummer H3 equipped with an automatic transmission.
Frequently Asked Questions
What does the TCM do on a 2008-2010 Hummer H3?
The Transmission Control Module (TCM) acts as the computer for your automatic transmission. It collects data from various sensors on the engine and transmission to control shift timing, fluid pressure, and torque converter lockup, ensuring smooth and efficient operation.
Is this module truly ‘plug-and-play’?
Yes. We program the module to your vehicle’s specific VIN before shipping. This critical step ensures it communicates correctly with your H3’s other computers right out of the box, eliminating the need for expensive dealership programming.
Where is the TCM located on my Hummer H3?
For the 2008-2010 Hummer H3, the transmission control module is conveniently located in the engine compartment, specifically on the right-hand (passenger side) rear area of the bay, making it easily accessible for replacement.
Will this part fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem and has requested the check engine light to be turned on. While P0700 itself doesn’t pinpoint the TCM as the failure, it is very commonly present when the TCM has failed. Replacing a faulty TCM will resolve the underlying issue causing the P0700 code.
Do I need to return my old TCM?
No, there is absolutely no core charge for this part. You can keep your old module without any extra fees or hassle, simplifying your repair process.