Restore Peak Transmission Performance to Your Hummer H3
Is your 2008-2010 Hummer H3 suffering from erratic shifting, getting stuck in gear, or throwing transmission-related check engine lights? These are classic signs of 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 cripple your vehicle’s drivability and reliability. This genuine OEM-quality T42 TCM, part number 24241806, is the definitive solution, pre-programmed to your vehicle’s specific VIN for a true plug-and-play installation.
From the Diagnostic Bay
We recently had a 2009 Hummer H3 in the shop with classic transmission woes: harsh 1-2 shifts and occasionally getting stuck in 3rd gear. The owner had already spent a significant amount of money replacing shift solenoids and flushing the fluid, but the problem persisted. After connecting our diagnostic scanner, we saw intermittent communication loss with the TCM. Instead of continuing to throw parts at the transmission itself, we identified the root cause: the original TCM was failing internally. We installed one of our VIN-programmed T42 modules, and within 30 minutes, the H3 was shifting like it just rolled off the factory floor. This is a prime example of how correctly diagnosing the electronic controller can save you time, money, and frustration.
Common Symptoms of a Failing H3 TCM
- âś” Harsh, delayed, or unpredictable gear shifts that make driving uncomfortable.
- âś” Vehicle entering ‘limp mode,’ often stuck in 2nd or 3rd gear, with limited power.
- âś” The Check Engine Light or a specific transmission warning light is illuminated on your dash.
- âś” Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults are present.
- âś” A noticeable decrease in fuel efficiency as the transmission operates inefficiently.
- âś” Complete failure to shift, or the transmission feels like it’s slipping between gears.
- âś” Intermittent electrical issues that seem to have no other source.
Key Features of This 2008-2010 Hummer H3 TCM
This isn’t just a replacement part; it’s a comprehensive solution designed to restore your vehicle’s factory performance and reliability. By addressing the core electronic control issues, you prevent further mechanical wear and tear on your transmission.
- VIN-Programmed for Your Vehicle: We program this module with your Hummer’s exact Vehicle Identification Number (VIN) before it ships. This loads the latest GM software and ensures perfect communication with the engine and other vehicle systems right out of the box. No expensive trip to the dealership for programming is required.
- Direct-Fit OEM Quality: Manufactured to meet or exceed original equipment specifications, this module guarantees a perfect fit and reliable, long-term operation. It directly replaces a wide range of service numbers, including 24242391, 24234503, and 24252114.
- Restores Smooth Operation: By taking precise control over shift points, line pressure, and torque converter lockup, this module eliminates the frustrating shifting problems caused by a faulty original unit.
- No Core Charge: We make the repair process as simple as possible. You are not required to send your old, faulty module back, saving you time and shipping hassles.
Simple Installation Process
For the 2008-2010 Hummer H3, the TCM is conveniently located in the engine compartment on the right-hand (passenger) side, near the rear. The installation is straightforward for a DIY mechanic or a professional technician.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate and Remove: Identify the TCM. Carefully disconnect the electrical wiring harnesses by releasing their locking tabs.
- Swap the Module: Unbolt the old module from its mounting bracket and set it aside. Secure the new module in its place.
- Reconnect: Firmly plug the wiring harnesses back into the new TCM until they click into place. Reconnect the battery terminal.
- Final Steps: Start the vehicle. While our programming resolves most issues, it’s good practice to use a basic OBD2 scan tool to clear any stored DTCs from the vehicle’s memory.
Frequently Asked Questions
What is VIN programming and why is it essential?
VIN programming is the process of loading your vehicle’s specific software and calibrations onto the TCM. Every vehicle has slight variations, and this process ensures the module communicates perfectly with your H3’s engine, ABS, and other systems for optimal shift timing and performance. Without it, the module simply won’t work correctly.
Will this module fix a P0700 diagnostic code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While a failing TCM is a very common cause of a P0700 code, it’s important to check for other specific codes that may be present. This module is designed to resolve internal electronic faults within the TCM that often trigger these codes.
Can I install this part myself?
Yes, this is a common DIY repair. With basic hand tools and by following the steps outlined above, most vehicle owners can replace the TCM in under an hour. The plug-and-play nature of our VIN programming eliminates the most difficult step—the need for specialized software tools.
Is there a core charge or do I need to return my old part?
No, there is absolutely no core charge. You can keep, discard, or recycle your old module without any obligation, making for a hassle-free repair process.
How can I be sure the TCM is the problem, not the transmission itself?
While mechanical failures can cause shifting issues, problems that are intermittent, electrical in nature (like multiple solenoid codes at once), or involve a loss of communication with the scanner often point directly to the TCM. If your transmission fluid is clean and at the correct level, but you’re experiencing the electronic symptoms listed, the TCM is the most likely culprit.