Restore Crisp, Reliable Shifting to Your GMC Sierra
If you’re dealing with the frustration of a GMC Sierra that shifts harshly, gets stuck in gear, or throws transmission codes, you’re not alone. As a technician with over two decades of experience, I’ve seen countless GM trucks exhibit these exact issues. The culprit is often a failing Transmission Control Module (TCM). This VIN-programmed T42 TCM is the definitive solution, designed to restore the smooth, predictable performance your 2007-2013 Sierra 1500 Pickup had from the factory. It’s not just a part; it’s a permanent fix that eliminates the guesswork and costly dealership programming.
This module is the brain of your automatic transmission, controlling everything from shift points and line pressure to torque converter lockup. When it fails, communication breaks down, leading to the drivability problems you’re experiencing. Our module arrives pre-programmed to your truck’s specific VIN, ensuring it works perfectly right out of the box. This is the key to a successful, hassle-free repair for both seasoned mechanics and DIYers.
Case Study: A Tricky Diagnosis
A customer brought in his ’08 Sierra 1500, complaining it was stuck in what felt like third gear (limp mode) and the check engine light was on. His local shop had already replaced a shift solenoid with no success. I hooked up my scanner and pulled a P0700 (Transmission Control System Malfunction) and a U0101 (Lost Communication with TCM). Instead of chasing ghosts in the wiring, my experience pointed straight to the T42 TCM. These modules are known to fail internally, causing intermittent communication loss. We installed one of our VIN-programmed modules, cleared the codes, and the truck was shifting perfectly on the test drive. The customer saved hundreds by avoiding a dealership visit and unnecessary parts.
Is Your Truck Showing These Symptoms?
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ Vehicle is stuck in “limp mode” and will not shift out of 2nd or 3rd gear.
- ✔ Check Engine Light is on with transmission-related Diagnostic Trouble Codes (DTCs) like P0700, P0750, P0753, P0758, or other solenoid circuit codes.
- ✔ Inability to upshift or downshift, resulting in poor acceleration and terrible fuel mileage.
- ✔ The transmission seems to slip between gears or feels like it’s hunting for the right gear.
- ✔ Complete loss of communication with the TCM, preventing diagnostics.
A Straightforward Guide to Installation
Replacing the TCM on your Sierra is a job you can confidently tackle in your own driveway. For most 2007-2013 Sierra 1500 models, the module is conveniently located in the engine bay, right next to the battery. The entire process typically takes 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 electronic systems.
- Locate the Old Module: Find the TCM, which is a small silver box with electrical connectors, mounted next to the battery on a bracket.
- Disconnect and Remove: Carefully unplug the electrical harnesses. 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. Securely reconnect the electrical harnesses, making sure they click into place.
- Final Steps: Reconnect the negative battery terminal. While the module is plug-and-play, it’s always best practice to use a basic OBD2 scan tool to clear any stored fault codes from the system’s memory.
Will This Fit My Truck?
This T42 Transmission Control Module is a direct-fit replacement for the original part in a wide range of General Motors vehicles. It is guaranteed to be compatible with the following models, specifically including the 2007-2013 Sierra 1500 TCM application:
- GMC Sierra 1500/2500 Pickup (2007-2013): Located next to the battery.
- Chevrolet Silverado 1500/2500 Pickup (2007-2013): Located next to the battery.
- Chevrolet Tahoe & GMC Yukon (2007-2009): Located next to the battery.
- Chevrolet Suburban & GMC Yukon XL 1500 (2007-2008): Located next to the battery.
- GMC Savana & Chevrolet Express Vans (2006-2014): Located in the RH engine compartment.
- Hummer H3 (2008-2010): Located in the RH rear engine compartment.
- …and many other GM cars, trucks, and SUVs from 2006-2014 equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E.
This part directly interchanges with service numbers: 24241806, 24252114, 24234503, 24230461, 24234274, 24235340, 24239224, 24256960, and more.
Frequently Asked Questions
Do I need to take my truck to the dealer for programming?
No. This is the biggest benefit of our service. We program the module to your vehicle’s VIN before shipping it. This makes the installation plug-and-play, saving you the time and expense of a dealership visit.
Is this a new or used part?
This is a high-quality, OEM-spec replacement part that has been expertly tested and programmed. It is backed by our one-year warranty for your peace of mind, ensuring long-term reliability.
What tools do I need for the installation?
You’ll only need basic hand tools. Typically, a simple socket set to remove the mounting bolts and a flathead screwdriver to help release the connector tabs is all that’s required. The entire job is very straightforward.
What happens if I don’t provide my VIN?
Providing your VIN is crucial for the programming process. Without it, the module will not have the correct software for your truck’s specific configuration, and it will not function correctly. Please be sure to enter your VIN during checkout.
Is there a core charge?
No, there is absolutely no core charge. You can keep your old part, so there’s no need to worry about the hassle and expense of shipping it back to us.