Restore Peak Transmission Performance to Your Hummer H3
If your 2008, 2009, or 2010 Hummer H3 is suffering from erratic shifting, getting stuck in gear, or displaying a check engine light, a failing Transmission Control Module (TCM) is the most likely culprit. 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 cause a cascade of frustrating and potentially damaging issues. This genuine GM T42 TCM, service number 24255280, is the definitive solution to restore your vehicle’s drivability and reliability.
From the Diagnostic Bay
We had a 2009 Hummer H3 come into the shop that was completely stuck in what the owner called ‘fail-safe’ mode. It wouldn’t shift past 3rd gear, making highway driving impossible. The check engine light was on, and a generic scanner pulled a P0700 code, which just indicates a general transmission fault. After digging deeper, we found communication errors with the original TCM. The owner was worried about a multi-thousand dollar transmission rebuild. We installed one of our VIN-programmed T42 modules, cleared the codes, and had him back on the road in under an hour. It’s a classic case where the ‘brain’ fails, not the mechanicals, and this part is the precise, cost-effective fix.
Diagnosing a Faulty Hummer H3 TCM
The transmission control module is a sophisticated computer, and its failure can manifest in various ways. Recognizing the symptoms early can save you from further component damage and costly diagnostic fees. If your H3 is exhibiting any of the following behaviors, it’s time to inspect your TCM.
Common Symptoms of TCM Failure
- ✔ Harsh or Delayed Shifting: Your vehicle may slam into gear, hesitate before engaging, or feel like it’s slipping between shifts.
- ✔ Stuck in Limp Mode: The transmission may refuse to shift out of a single gear (often 2nd or 3rd) to prevent further damage.
- ✔ Warning Lights: The Check Engine Light or a specific transmission warning light will illuminate on your dashboard.
- ✔ Diagnostic Trouble Codes (DTCs): Common codes include P0700 (Transmission Control System Malfunction) and various solenoid-specific codes (e.g., P0750-P0758).
- ✔ Poor Fuel Economy: Inefficient shifting and torque converter lock-up control can lead to a noticeable drop in MPG.
- ✔ No Communication: In severe cases, a diagnostic scan tool may be unable to communicate with the TCM at all.
The Plug-and-Play Advantage: VIN Programming Included
What sets our modules apart is the essential VIN programming service we perform before shipping. Generic modules off the shelf require a trip to the dealership for expensive and time-consuming programming with their proprietary equipment. Our process eliminates that step entirely. We flash the module with your Hummer H3’s specific Vehicle Identification Number (VIN) and load the latest GM-certified software. This ensures the TCM works in perfect harmony with your vehicle’s engine control unit (ECU) and other systems right out of the box. It’s a true plug-and-play solution designed for both professional technicians and DIY installers.
Key Features and Direct Benefits
- ✔ Ready for Installation: Arrives pre-programmed to your VIN. No additional programming or dealer visits required.
- ✔ Restores Smooth Operation: Corrects harsh shifting, delayed engagement, and slipping for a like-new driving experience.
- ✔ Clears Fault Codes: Directly addresses the root cause of common transmission-related DTCs.
- ✔ OEM-Standard Quality: Built to meet or exceed original equipment specifications for lasting durability and performance.
- ✔ Simple Installation: Located in the right-hand rear of the engine compartment on the H3, making replacement a straightforward process that typically takes less than 30 minutes.
- ✔ One-Year Warranty: Purchase with confidence knowing your part is backed by a comprehensive one-year warranty.
This module is also a direct replacement for a wide range of other GM part numbers, including 24242391, 24234503, 24252114, 24230461, and more, making it a versatile solution for many GM trucks and SUVs from this era.
Frequently Asked Questions
What is VIN programming and why do I need it?
VIN programming loads your vehicle’s specific software and calibration files onto the TCM. This is critical for the module to communicate correctly with your H3’s engine and other systems. Without it, the transmission will not function properly. We handle this for you, so the part is ready to install upon arrival.
Do I need to visit a dealer after installing this part?
No. Because we pre-program the module to your vehicle’s VIN, you can skip the expensive trip to the dealership. The installation is complete once the part is physically installed and any stored trouble codes are cleared with a standard scan tool.
Where is the TCM located on a 2008-2010 Hummer H3?
On the Hummer H3 models from 2008 to 2010, the Transmission Control Module is typically found in the engine compartment, on the right-hand (passenger) side towards the rear.
Will this module fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While this module often resolves the underlying issue causing the P0700, it’s always best to scan for more specific codes (like solenoid or sensor codes) to confirm the TCM is the point of failure. In most cases where shifting performance is poor, a faulty TCM is the cause.
Is there a core charge for my old TCM?
No, there is no core charge associated with this part. You can keep your old module without any need to send it back, simplifying the repair process for you.