If you’re dealing with the frustrating and often unpredictable issues of a failing transmission control module (TCM) in your GMC Sierra, you’ve come to the right place. As a technician with over two decades of experience under the hood, I’ve seen firsthand how a faulty TCM can sideline a perfectly good truck. This isn’t just an inconvenience; it’s a critical failure that can affect safety and performance. That’s why we offer this OEM-quality T42 Transmission Control Module, specifically programmed to your truck’s VIN, to provide a reliable, long-term solution.
This module is the brain of your automatic transmission, controlling everything from shift points and line pressure to torque converter clutch engagement. When it starts to fail, the symptoms can range from mildly annoying to downright dangerous. This part is your direct-fit, plug-and-play fix, eliminating the need for expensive dealership visits for programming. We handle that for you before it ships, ensuring that when it arrives, you can get your truck back to shifting smoothly and reliably.
Case Study: A Tricky Diagnosis
I remember a 2011 Sierra 1500 that came into my shop. The owner was at his wit’s end. He described intermittent, bone-jarring shifts and occasional ‘limp mode’ where the truck would get stuck in 3rd gear. He’d already replaced a shift solenoid on another mechanic’s advice, but the problem persisted. After hooking up my scan tool, I saw a generic P0700 code, but also intermittent communication loss with the TCM. Heat soak was making the issue worse. Instead of throwing more parts at it, we installed one of our VIN-programmed T42 modules. The difference was immediate. The communication was stable, the codes were gone, and the truck shifted like it just rolled off the factory floor. This is the definitive fix for these common electronic failures.
Is Your Sierra Exhibiting These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission failure. Often, the signs are electronic. Watch out for these common symptoms that point directly to a faulty module:
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ The truck refuses to shift out of a single gear (often called “limp mode”).
- ✔ An illuminated Check Engine Light or Transmission Warning Light.
- ✔ Diagnostic Trouble Codes (DTCs) stored in the system, especially P0700 (Transmission Control System Malfunction), P0750, or other solenoid-related codes.
- ✔ Poor acceleration and a noticeable drop in fuel economy.
- ✔ The transmission seems to slip between gears or fails to downshift when slowing down.
Solving the Problem with a Pre-Programmed 2007-2013 Sierra 1500 TCM
The biggest hurdle in replacing a modern electronic module is programming. We remove that obstacle completely. By providing your vehicle’s VIN at checkout, we load the latest GM-certified software directly onto your new module. This ensures it communicates perfectly with your truck’s engine computer (ECM) and other systems right out of the box. You get optimized shift strategies and restored performance without paying for dealer labor or diagnostic time.
A Straightforward Guide to Installation
For the 2007-2013 GMC Sierra 1500, this is a repair you can confidently tackle in your own driveway. The TCM is typically located right next to the battery in the engine bay, making access simple. The entire process should take less than 30 minutes.
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts and to help reset the vehicle’s computer systems.
- Locate the Module: Open the hood and find the TCM mounted next to the battery tray. It’s a silver box with several large electrical connectors.
- Disconnect and Remove: Carefully unclip the wiring harnesses. They have locking tabs, so don’t force them. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Reconnect the wiring harnesses, ensuring they click securely into position.
- Final Steps: Reconnect the negative battery terminal. While the module is plug-and-play, it’s always good practice to use a basic OBD-II scan tool to clear any lingering fault codes from the computer’s memory.
Verified Compatibility for Your GM Vehicle
This T42 TCM is a direct replacement for part number 24239224 and other service numbers listed below. It is guaranteed to fit the following models, among many others:
- GMC Sierra 1500 Pickup: 2007 (New Body Style), 2008, 2009-2013 (w/o hybrid)
- Chevrolet Silverado 1500 Pickup: 2007 (New Body Style), 2008, 2009-2013 (w/o hybrid)
- GMC/Chevrolet Vans (Savana/Express): 2006-2014
- Chevrolet Tahoe / GMC Yukon: 2007-2009
- Chevrolet Avalanche 1500: 2007-2008
- …and many other GM cars, trucks, and SUVs equipped with 4L60E, 4L65E, and 4L70E transmissions from 2006-2014. Please check the full fitment list to confirm your specific vehicle.
Frequently Asked Questions
Do I need to take this part to a dealer for programming?
No. This is the biggest benefit we offer. We program the module to your vehicle’s VIN before shipping, so it’s ready for immediate installation. This saves you time and the high cost of dealership programming.
Is this a difficult part to install myself?
Not at all. For most Sierra and Silverado trucks, the TCM is located next to the battery and can be swapped with basic hand tools in under 30 minutes. Our installation guide above walks you through the simple process.
What if I install it and still have problems?
While this module is the solution for the vast majority of electronic transmission faults, we stand behind our parts. Each module comes with a one-year warranty. If you have any issues, our expert support team is here to help you troubleshoot.
What is a core charge? Do I need to send my old part back?
There is no core charge for this part. You can keep your old module or recycle it locally without the hassle of shipping it back to us.
Will this fix a P0700 trouble code?
Yes. The P0700 code is a general fault code indicating the TCM has detected a problem. In many cases, a failing TCM is the root cause. Replacing it with our pre-programmed unit will often resolve the P0700 code and any related specific codes (like for solenoids or sensors).