If your 2007 Chevrolet Silverado 2500 is suffering from harsh shifting, getting stuck in gear, or throwing transmission codes, 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 mimic a catastrophic transmission failure, leading to costly misdiagnoses. This T42 TCM, part number 24238856, is the reliable, direct-fit solution to restore your truck’s performance and get you back on the road with confidence.
The TCM is the brain of your automatic transmission, responsible for managing every shift point, controlling torque converter lockup, and monitoring system health. When it fails, often due to heat and vibration in the engine bay, the symptoms can be alarming. This replacement module is built to OEM specifications for durability and is pre-programmed to your truck’s specific Vehicle Identification Number (VIN). This means no expensive trips to the dealership for programming—it’s a true plug-and-play fix that arrives ready for installation.
A Technician’s Notebook: The Silverado That Dodged a Rebuild
I once had a 2007 Silverado 2500 with the 6.0L towed into my shop. The owner was frustrated, having been told by another shop he needed a full transmission rebuild costing over $4,000. The truck was stuck in 3rd gear (limp mode) and had a P0700 code. I hooked up my professional scan tool, and while the generic P0700 was present, I dug deeper and found specific solenoid circuit codes. Instead of condemning the transmission, I checked the TCM connectors for corrosion—they were clean. My experience pointed to an internal TCM failure, a common issue on these GMT900 trucks. We installed one of our VIN-programmed T42 modules. In less than an hour, the truck was shifting perfectly, all codes were gone, and the customer saved thousands. It’s a powerful reminder to always diagnose the electronics before condemning the hard parts.
Is Your Silverado Showing These Telltale Signs?
- ✔ Harsh, erratic, or delayed gear shifts that make driving uncomfortable and unpredictable.
- ✔ The vehicle is stuck in “limp mode,” typically locked in 2nd or 3rd gear, with limited power.
- ✔ Check Engine Light or Transmission Warning Light is illuminated on the dash.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700 (Transmission Control System Malfunction), P0750-P0758 (Shift Solenoid errors), or other communication codes.
- ✔ Poor acceleration, failure to upshift or downshift, and a noticeable drop in fuel economy.
- ✔ Complete loss of communication with the transmission module, leading to a no-start or no-shift condition.
Your 30-Minute TCM Installation Guide
Replacing the TCM on your Silverado 2500 is a straightforward job for any DIYer. For this specific model, you’ll find it located right next to the battery in the engine compartment.
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts and to help reset the vehicle’s electronic systems.
- Locate the Module: Open the hood and find the TCM mounted on a bracket next to the battery. It’s a silver box with two large electrical connectors.
- Disconnect and Remove: Carefully unclip and remove the two wiring harness connectors. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Mount your new, VIN-programmed TCM onto the bracket and securely fasten the bolts. Re-attach the two wiring harness connectors, ensuring they click into place.
- Final Steps: Reconnect the negative battery terminal. Start the engine and use a basic OBD2 scan tool to clear any stored fault codes. Take your truck for a test drive to confirm smooth shifting.
Guaranteed Fitment For Your GM Vehicle
This T42 TCM is a direct replacement for part number 24238856 and is interchangeable with many other service numbers. It fits a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L80E. While this page is focused on the 2007 Silverado 2500 Transmission Control Module, please verify fitment for other models below:
- Chevrolet Silverado 2500 PICKUP (2007): New body style (smooth door skin), 6.0L, located next to the battery.
- GMC Sierra 2500 PICKUP (2007): New body style (smooth door skin), 6.0L, located next to the battery.
- Chevrolet & GMC Express/Savana Vans (2006-2014): Located in the RH engine compartment.
- Chevrolet Tahoe & GMC Yukon (2007-2009): Located next to the battery.
- Hummer H3 (2008-2010): Located in the RH rear engine compartment.
- …and many other GM cars, trucks, and SUVs from 2006-2014. Please see the full fitment list provided.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
VIN programming means we load your vehicle’s specific identification number and the latest GM-certified software onto the module before we ship it. This ensures it communicates perfectly with your truck’s engine computer and other systems, just like a part from the dealer, but without the extra cost and hassle of a programming service.
Do I need any special tools for this installation?
No special tools are required. Basic hand tools, like a socket set to remove the module’s mounting bolts and disconnect the battery, are all you need. An OBD2 scanner is recommended to clear codes, but not strictly necessary as disconnecting the battery often does the trick.
Is there a core charge? Do I have to return my old TCM?
No, there is no core charge for this part. You can keep your old module or dispose of it responsibly without any need to send it back to us, simplifying the repair process for you.
Will this fix a ‘limp mode’ problem?
Yes, in the vast majority of cases. Limp mode is a protective measure triggered by the vehicle’s computer when it detects a serious fault, and a failing TCM is one of the most common culprits. Replacing it with this pre-programmed unit is a primary fix for this issue.
How does this part compare to one from a dealership?
This module is built to meet or exceed original equipment (OEM) standards for performance and reliability. The key benefit is that ours arrives pre-programmed for your VIN, saving you the separate programming fee (often $150+) and scheduling time required when you buy from a dealership.