Get Your GMC Sierra Shifting Smoothly Again
If you’re dealing with the frustration of a transmission that won’t shift correctly, bangs into gear, or has your truck stuck in limp mode, you’ve come to the right place. As a technician with over two decades of experience, I’ve seen countless GM trucks sidelined by a faulty Transmission Control Module (TCM). This VIN-programmed T42 TCM is the direct-fit, reliable solution for your 2007 Sierra 2500 Transmission Module, designed to restore factory performance without a costly trip to the dealership.
The TCM is the brain of your automatic transmission, controlling everything from shift points to torque converter lockup. When it fails, symptoms can range from annoying to dangerous. This replacement module, part number 24239926, is pre-programmed with your vehicle’s specific VIN and the latest GM software. This means it arrives ready for a true plug-and-play installation, eliminating the need for expensive scan tools or programming fees. It’s the definitive fix for common transmission diagnostic trouble codes (DTCs) and performance issues that plague these otherwise dependable trucks.
A Technician’s Notebook
I remember a 2007 Sierra 2500 that came into my shop with a classic complaint: “It shifts hard sometimes, especially after it’s warm.” The owner had already replaced a shift solenoid with no luck. A quick scan showed a generic P0700 code but no specific solenoid faults. Experience pointed me straight to the T42 TCM. These modules, especially on work trucks, are prone to internal failure from heat cycles and vibration. After swapping in a VIN-programmed module, the truck’s shifting was instantly crisp and predictable. It’s a 30-minute fix that solves a problem many chase for weeks.
Is Your Sierra 2500 Exhibiting These Telltale Signs?
A failing TCM often gives clear warnings. If your truck is experiencing any of the following, a faulty module is the likely culprit:
- âś” Harsh, clunky, or erratic gear changes.
- âś” The vehicle is stuck in a single gear (often called “limp mode”).
- âś” Check Engine Light or Transmission Warning Light is on with codes like P0700, P0750, or other solenoid-related faults.
- âś” Delayed engagement when shifting from Park to Drive or Reverse.
- âś” Failure to upshift or downshift properly, leading to poor acceleration and fuel economy.
- âś” Intermittent loss of communication with the module, causing unpredictable behavior.
Straightforward 30-Minute Installation Guide
You don’t need to be a master mechanic to install this part. The process is simple and can be done with basic hand tools right in your driveway.
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent electrical shorts and help reset the system.
- Locate the Module: On your 2007 Sierra 2500, the TCM is typically located in the engine compartment, right next to the battery.
- Disconnect and Remove: Carefully unplug the electrical connectors. Use a small screwdriver to release the locking tabs if necessary. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Reconnect the electrical harnesses, ensuring they click securely into position.
- Final Steps: Reconnect the battery terminal. Start the vehicle and allow it to idle for a few minutes. While the module is pre-programmed, it’s good practice to use a basic scan tool to clear any stored DTCs from the system.
Verified Vehicle Compatibility
This T42 TCM, also known by service numbers 24242391, 24234503, and 24252114, is a direct replacement for a wide range of GM vehicles. While this page focuses on the 2007 Sierra 2500 Transmission Module, it also fits the following models. Please verify your specific application.
- GMC Sierra / Chevrolet Silverado (1500, 2500, 3500): 2007-2013 (Check specific options)
- GMC Savana / Chevrolet Express (1500, 2500, 3500): 2006-2014
- GMC Yukon / Chevrolet Tahoe / Suburban: 2007-2009
- Chevrolet Colorado / GMC Canyon: 2008-2012
- Hummer H3: 2008-2010
- Chevrolet Impala, Cobalt, HHR; Pontiac G5, G6; Saturn Ion, Vue, Aura and many more GM cars and SUVs from 2006-2011.
Frequently Asked Questions
Do I need to get this module programmed by a dealer?
No. This module is delivered to you pre-programmed to your vehicle’s VIN. You can install it yourself and it will work immediately, saving you time and money on dealership programming fees.
Where is the TCM located on my 2007 Sierra 2500?
For the 2007 Sierra 2500 (new body style), the Transmission Control Module is conveniently located in the engine bay, mounted right next to the battery. This makes for a very quick and easy replacement.
Will this fix a P0700 trouble code?
Yes. A P0700 code is a general fault code indicating the TCM has detected a problem. Replacing a faulty TCM with this pre-programmed unit is a very common and effective way to resolve a P0700 code and the underlying shifting issues.
Is this part difficult to install for a DIYer?
Not at all. This is one of the easier electronic components to replace. With basic hand tools and our installation guide, most people can complete the job in under 30 minutes. The biggest benefit is saving on labor costs.
Is there a core charge for my old part?
No, there is no core charge. You are not required to send your old, faulty module back to us, which simplifies the repair process for you.