Restore Peak Transmission Performance to Your GM Truck
If you’re dealing with the frustration of a transmission that won’t shift correctly, is stuck in limp mode, or has thrown a check engine light, you’ve come to the right place. As a technician with over two decades of experience, I’ve seen firsthand how a failing Transmission Control Module (TCM) can sideline a perfectly good truck. This T42 series module, part number 24235340, is the definitive solution for your 2007 GMC Sierra 2500 and a wide range of other GM vehicles. The TCM is the electronic brain of your automatic transmission, responsible for every gear change, torque converter lockup, and line pressure adjustment. When it fails, the symptoms can be alarming, but the fix doesn’t have to be complicated or expensive.
What sets this module apart is our expert VIN programming service. Before we ship it, we flash the module with your vehicle’s specific VIN and the latest GM software updates. This means it arrives at your door ready for a true plug-and-play installation, eliminating the need for a costly trip to the dealership for programming. This is the exact approach I’ve used in my own shop to save customers hundreds of dollars and get their vehicles back on the road the same day. This isn’t just a part; it’s a complete, hassle-free solution to restore the smooth, reliable shifting you depend on.
Case Study: A Tricky Diagnosis
A customer brought in his ’07 Sierra 2500 HD with the 6.0L, complaining of harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode), especially when towing. He’d already replaced a shift solenoid based on a generic code, but the problem persisted. His scanner showed a P0700 (Transmission Control System Malfunction). In my experience, while solenoid codes can be direct, a P0700 is often the TCM itself reporting a general fault. We checked the wiring and connectors—all solid. The culprit was a classic internal failure in the original 2007 Sierra 2500 TCM. Instead of a costly diagnostic rabbit hole, we installed one of our VIN-programmed modules. In under an hour, the truck was shifting perfectly, the codes were gone, and the customer was relieved he didn’t need a transmission rebuild.
Is Your Truck’s TCM Trying to Tell You Something?
A faulty TCM can manifest in various ways. If you’re experiencing any of the following, a replacement is likely the solution:
- ✔ Unpredictable or harsh gear shifts that slam into gear.
- ✔ The transmission refuses to shift up or down from a specific gear.
- ✔ Your vehicle is stuck in “limp mode,” typically locked in 2nd or 3rd gear.
- ✔ An illuminated Check Engine Light or Transmission Warning Light is present.
- ✔ Diagnostic Trouble Codes (DTCs) are stored, such as the general P0700 or specific solenoid codes like P0750, P0751, etc.
- ✔ A noticeable drop in fuel economy or signs of the transmission overheating.
- ✔ Complete loss of communication with the module, preventing diagnostics.
DIY Installation: A Straightforward Guide
Replacing the TCM is a job most DIYers can handle in their own driveway in about 30 minutes. For the 2007 Sierra 2500, it’s conveniently located next to the battery in the engine compartment.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and help reset the system.
- Locate the Module: On your Sierra, find the TCM mounted in the engine bay, typically right next to the battery.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that need to be released. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place and securely reconnect the electrical harnesses. You should hear a click as they lock.
- Final Steps: Reconnect the battery terminal. Start the vehicle and allow it to idle for a few minutes. If you have a basic scan tool, it’s good practice to clear any lingering fault codes from the computer’s memory.
Verified Vehicle Compatibility
This module is a direct replacement for part number 24235340 and other interchangeable numbers. It is guaranteed to fit the following models, among many others:
- ✔ GMC Sierra 2500 Pickup (2007): New body style, 6.0L, located next to the battery.
- ✔ Chevrolet Silverado 2500 Pickup (2007): New body style, 6.0L, located next to the battery.
- ✔ GMC & Chevrolet 1500 Trucks (2007-2013): Various configurations, typically next to the battery.
- ✔ GMC & Chevrolet Vans (Savana, Express 1500/2500/3500, 2006-2014): Located in the RH engine compartment.
- ✔ Chevrolet Tahoe & GMC Yukon (2007-2009): Located next to the battery.
- ✔ Cadillac, Buick, Pontiac, Saturn, Hummer & Saab models (2006-2011): Wide compatibility with vehicles using the T42 TCM. Please verify your specific model in the fitment list.
Frequently Asked Questions
Do I need to take my truck to a dealer after installation?
No. This module comes fully programmed to your vehicle’s VIN. It is a true plug-and-play solution, saving you the time and expense of dealership programming.
What if my part number is slightly different?
This module, 24235340, is interchangeable with many other GM service numbers like 24252114, 24234503, and 24256960. As long as your vehicle is on our compatibility list, this module will function correctly as a replacement.
Is a core charge required for my old TCM?
No, there is no core charge. You can keep your old part without any hassle or need to return it.
Will this fix a P0700 code?
In many cases, yes. A P0700 code is a general fault request from the TCM to the Engine Control Module (ECM) to turn on the check engine light. A failing TCM is a very common cause of this code. This programmed replacement is designed to resolve these internal electronic faults.