Restore Peak Transmission Performance in Your GM Vehicle
If your 2007-2013 GMC Sierra 1500, Chevrolet Silverado, or other compatible GM vehicle is suffering from erratic shifting, slipping gears, or has entered a frustrating “limp mode,” a failing Transmission Control Module (TCM) is the most likely culprit. The TCM is the electronic brain of your automatic transmission, responsible for orchestrating every gear change and ensuring smooth, efficient operation. When it fails, it can cause a cascade of problems that affect drivability, fuel economy, and safety. This T42 TCM, service part number 24243901, is the definitive solution, arriving expertly programmed to your vehicle’s specific VIN for a seamless, plug-and-play installation.
From the Diagnostic Bay
We had a 2009 Silverado 1500 come into the shop with classic symptoms: harsh 1-2 shifts and occasionally getting stuck in 3rd gear. The owner had already spent a few hundred dollars replacing a couple of shift solenoids based on a forum recommendation, but the problem persisted. After a quick scan, we saw the tell-tale communication error codes pointing to the TCM. Instead of chasing ghosts in the valve body, we installed one of our VIN-programmed T42 modules. The truck was shifting like new in under an hour. It’s a common story—diagnosing the root cause saves time and money, and for these 4-speed GM transmissions, the TCM is often the correct first step.
Is Your Truck Showing Signs of a Faulty TCM?
A failing transmission module can manifest in several ways. If you’re experiencing any of the following issues, it’s a strong indicator that your TCM needs replacement:
- ✔ Harsh, delayed, or unpredictable gear shifts that make driving uncomfortable.
- ✔ The vehicle is stuck in a single gear (often 2nd or 3rd), a condition known as “limp mode.”
- ✔ The Check Engine Light or a dedicated transmission warning light is illuminated on your dashboard.
- ✔ Diagnostic scans reveal trouble codes such as P0700 (Transmission Control System Malfunction) or various solenoid-specific codes (e.g., P0750, P0753, P0758).
- ✔ A noticeable decrease in fuel efficiency as the transmission fails to operate in the optimal gear.
- ✔ Complete loss of communication with the transmission, leading to a no-shift condition.
Your Direct-Fit Sierra 1500 Transmission Module Solution
This isn’t just a replacement part; it’s a complete, hassle-free repair solution. The most critical aspect of replacing a modern TCM is programming. Our service eliminates this costly and time-consuming step. We use the latest GM software updates to program the module to your vehicle’s unique VIN before it ships. This ensures that all shift points, torque converter lockup strategies, and diagnostic parameters are perfectly matched to your truck’s factory specifications. The result is restored performance and reliability without a mandatory trip to the dealership. This module is built to meet or exceed original equipment standards, providing a durable and dependable fix for your transmission woes.
Installation is straightforward for a DIY mechanic or any professional technician. The TCM is typically located in the engine compartment, often near the battery, on a strut tower, or under the air cleaner box, depending on your specific model. Simply disconnect the battery, unbolt the old module, unplug the connectors, and install the new one in its place. Once the battery is reconnected, the vehicle will recognize the new, programmed module. We recommend using a basic scan tool to clear any stored diagnostic trouble codes (DTCs) after installation is complete.
Frequently Asked Questions
What does a T42 Transmission Control Module do?
The T42 TCM is an electronic computer that controls all functions of 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. It reads data from various sensors to determine the perfect time to shift gears, control line pressure, and engage the torque converter clutch for optimal performance and fuel economy.
Is this a true plug-and-play part?
Yes. Because we pre-program the module to your vehicle’s VIN, it is ready for installation right out of the box. You do not need to visit a dealership or use specialized scan tools for programming. Just install it, clear any old codes, and drive.
Where is the TCM located on my 2008 GMC Sierra 1500?
On the 2007-2013 Sierra and Silverado pickups, the T42 TCM is most commonly found in the engine bay, mounted next to the battery. Always confirm the location on your specific vehicle before beginning the replacement.
Will this fix transmission error codes like P0700?
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 will resolve the underlying issue that causes P0700 and other related transmission codes to appear.
Do I need to return my old TCM? Is there a core charge?
No, there is no core charge for this part. You can keep your old module, eliminating the hassle and expense of shipping a core back.