If your GMC Sierra is struggling with harsh shifting, getting stuck in gear, or throwing transmission codes, the problem often points directly to a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen how a faulty TCM can sideline an otherwise perfectly good truck. This T42 Transmission Control Module is the definitive, reliable solution, pre-programmed specifically to your truck’s VIN for a true plug-and-play fix that gets you back on the road without a trip to the dealership.
Is Your Sierra Exhibiting These Telltale Signs?
A failing TCM isn’t subtle. It’s the electronic brain of your 4L60E, 4L65E, or 4L70E transmission, and when it malfunctions, you’ll know it. Look out for these classic symptoms:
- ✔ Abrupt, jerky, or delayed gear shifts that make driving uncomfortable and unpredictable.
- ✔ The truck is stuck in “limp mode,” often locked in 2nd or 3rd gear, with no ability to upshift or downshift.
- ✔ Your dashboard is lit up with a Check Engine Light or Transmission Warning Light, showing diagnostic trouble codes (DTCs) like P0700 or various solenoid codes (P0750, P0751, etc.).
- ✔ A sudden and unexplained drop in fuel economy as the transmission operates inefficiently.
- ✔ The transmission seems to slip out of gear or fails to engage properly from Park to Drive or Reverse.
Core Benefits of This Programmed TCM
This isn’t just a replacement part; it’s a complete solution designed to restore your vehicle’s performance and save you time and money. Here’s what makes our 2007-2013 Sierra 1500 TCM the smart choice:
- ✔ VIN-Programmed for Your Truck: We flash the module with your vehicle’s specific VIN and the latest GM software updates before it ships. This ensures perfect communication between the TCM, engine, and other vehicle systems right out of the box. No dealer programming is required.
- ✔ Restores Smooth Operation: By precisely managing shift solenoids, line pressure, and torque converter lockup, this module eliminates the erratic behavior caused by a failing original unit.
- ✔ Built for Durability: Constructed to meet or exceed OEM specifications, this module is engineered to withstand the demanding conditions of daily driving and heavy workloads. It’s backed by a one-year warranty for your peace of mind.
- ✔ No Core Charge: Keep your old part. We don’t require a core return, which simplifies the process and saves you the hassle and expense of shipping your old module back.
Case Study: The Sierra That Wouldn’t Shift
A customer brought in his ’09 Sierra 1500, complaining it felt like it was “fighting him” on the road. It would slam into gear from a stop and refuse to shift past 3rd on the highway. A quick scan showed a P0700 code—a general transmission fault. After checking the fluid and connectors, my experience pointed to the TCM. These modules are notorious for internal electronic failures after years of heat cycles. We installed one of our pre-programmed TCMs, and the change was immediate. The truck shifted like it just rolled off the factory floor. This simple swap saved the customer from a potential transmission rebuild and hundreds in dealership diagnostic fees.
Get Your Truck Back on the Road: A Simple Installation Guide
For most 2007-2013 Sierra 1500 models, this is a straightforward DIY job that takes less than 30 minutes. The module is typically located in the engine bay, right next to the battery.
- Safety First: Always disconnect the negative terminal from your truck’s battery to prevent any electrical shorts and to help reset the vehicle’s computer systems.
- Locate the Old TCM: On your Sierra, find the module mounted near the battery. It will have several large electrical connectors attached.
- Disconnect and Remove: Carefully unclip the wiring harnesses. Then, unbolt the module from its mounting bracket. Keep track of the mounting hardware.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely reconnect the wiring harnesses, making sure each clip clicks firmly into place.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s good practice to use a basic scan tool to clear any stored fault codes from the vehicle’s memory. Start the truck and enjoy smooth shifting!
Verified Compatibility for Your GM Vehicle
While this is a perfect fit for the 2007-2013 Sierra 1500 TCM replacement, it is also a direct replacement for numerous other GM cars, trucks, and SUVs. It interchanges with part numbers 24252114, 24234503, 24235340, and others. Please see the detailed list below:
- GMC Sierra/Chevrolet Silverado 1500/2500 (2007-2013): Located next to the battery.
- GMC Yukon/Chevrolet Tahoe/Suburban (2007-2009): Located next to the battery.
- GMC Savana/Chevrolet Express Vans (2006-2014): Found in the RH engine compartment.
- Cadillac DTS (2006-2011): Located in the RH front engine compartment.
- Chevrolet Impala/Monte Carlo (2006-2011): Found under the lower air cleaner housing.
- …and many more models from Buick, Pontiac, Saturn, Hummer, and Saab. Please verify your specific model and year in the fitment chart.
Frequently Asked Questions
Frequently Asked Questions
Do I need to take my truck to a dealer after installing this TCM?
No. This module arrives pre-programmed to your vehicle’s VIN. The installation is a simple bolt-in, plug-in process, saving you from expensive dealership programming fees.
Is this a reliable part?
Absolutely. It’s built to strict OEM-quality standards to ensure long-lasting performance and reliability for your transmission. We back it with a solid one-year warranty.
What tools do I need for installation?
For most vehicles like the Sierra 1500, you will only need basic hand tools, such as a socket wrench set to disconnect the battery and unbolt the module. No special equipment is required.
Will this fix a P0700 trouble code?
Yes. A P0700 code is a general fault code indicating the TCM has detected a problem. If the TCM itself is the source of the fault, replacing it with this programmed unit will resolve the issue and allow the code to be cleared.
What is the difference between a TCM and a PCM/ECM?
The TCM (Transmission Control Module) exclusively manages the automatic transmission’s functions. The PCM (Powertrain Control Module) or ECM (Engine Control Module) manages the engine’s functions. In many modern vehicles, they are separate but communicate constantly. This part is for the transmission only.