Restore Crisp, Reliable Shifting to Your GM Truck
Is your GMC Sierra 2500 suffering from harsh shifting, getting stuck in gear, or throwing transmission codes? A faulty Transmission Control Module (TCM) is often the culprit. As a technician with over two decades of experience, I’ve seen how a failing TCM can sideline a perfectly good truck. This T42 series TCM is the definitive, reliable solution, pre-programmed to your truck’s specific VIN for a true plug-and-play repair that gets you back on the road without a trip to the dealership.
Case Study: A Tricky Diagnosis
A customer brought in his ’07 Sierra 2500 with a 6.0L, complaining of intermittent, bone-jarring shifts and occasionally getting stuck in what felt like third gear. He’d already replaced a shift solenoid with no luck. On my scan tool, I saw a generic P0700 code but also intermittent communication loss with the TCM. Instead of just throwing more parts at it, we inspected the module itself. After swapping in one of our VIN-programmed T42 modules, the problem was solved instantly. The pre-programming ensured all the specific shift strategies for his heavy-duty truck were loaded correctly, something a generic, un-programmed module can’t guarantee.
Is Your Sierra Exhibiting These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission failure. Often, the signs are electronic. If you’re experiencing any of the following, this module is your likely solution.
- ✔ Unpredictable, harsh, or delayed gear shifts.
- ✔ The truck is stuck in “limp mode” and won’t shift out of a single gear.
- ✔ Check Engine Light is on with transmission-related Diagnostic Trouble Codes (DTCs) like P0700, P0750, P0755, or other solenoid circuit codes.
- ✔ Complete failure to upshift or downshift.
- ✔ A noticeable drop in fuel economy or the transmission overheating.
- ✔ Inconsistent communication with the scan tool or other modules.
The Solution: A Properly Programmed 2007 Sierra 2500 TCM
The T42 TCM is the electronic brain of your 4-speed automatic transmission (like the 4L80E in your Sierra). It controls everything from shift timing to torque converter clutch engagement. Our process ensures this replacement works flawlessly from the moment you install it. We flash the module with the latest GM-certified software matched directly to your vehicle’s VIN. This eliminates software conflicts that cause persistent shifting problems and saves you hundreds in dealership programming fees.
A Straightforward Guide to Installation
For the 2007 GMC Sierra 2500, this is a repair most owners can handle in their own driveway in under 30 minutes. No special tools are required.
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts and to help reset the system.
- Locate the TCM: On your ’07 Sierra, the TCM is typically located in the engine bay, mounted right next to the battery.
- Disconnect and Remove: Carefully unclip the electrical connectors. Be gentle with the plastic tabs. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place and securely reconnect the electrical harnesses. You should hear a ‘click’ as they lock in.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the truck and allow it to idle for a few minutes. If you have a basic scan tool, it’s good practice to clear any stored DTCs.
Verified Vehicle Compatibility
This T42 TCM, part number 24239926, is a direct replacement for a wide range of General Motors vehicles from approximately 2006-2014. While this page is focused on the 2007 Sierra 2500 TCM, it also fits other models. Key compatibility includes:
- ✔ GMC Sierra / Chevrolet Silverado (1500, 2500): 2007 (New Body Style) – 2013
- ✔ GMC Yukon / Chevrolet Tahoe / Suburban: 2007 – 2009
- ✔ GMC Savana / Chevrolet Express (1500, 2500, 3500): 2006 – 2014
- ✔ Hummer H3: 2008 – 2010
- ✔ Chevrolet Colorado / GMC Canyon: 2008 – 2012
- ✔ And many other GM cars, trucks, and SUVs. This part is interchangeable with service numbers like 24252114, 24234503, 24242391, and more.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
It means we load the module with your vehicle’s unique Vehicle Identification Number (VIN) and the corresponding factory software before we ship it. This makes the module ready for immediate installation without needing expensive programming tools or a visit to a dealership, ensuring it works perfectly with your truck’s specific configuration.
Do I need to send my old TCM back?
No, there is no core charge for this part. You can keep your old module or dispose of it responsibly without any hassle or extra cost.
Will this fix a P0700 trouble code?
A P0700 code is a generic code indicating the TCM has detected a fault. While this module often resolves the root cause (like an internal TCM failure), you should ensure other components like wiring and solenoids are in good condition. In many cases I’ve diagnosed, a faulty TCM was the direct cause of the P0700 code.
Is this a difficult part to install myself?
Not at all. For a 2007 Sierra 2500, the TCM is easily accessible next to the battery in the engine bay. With basic hand tools, most people can swap the module in under 30 minutes. Just follow our installation guide above.
What kind of warranty is included?
This transmission control module is backed by a one-year warranty, giving you confidence and peace of mind in your repair.