Restore Peak Transmission Performance in Your GMC Sierra
Is your 2007-2013 GMC Sierra 1500 suffering from erratic shifting, getting stuck in gear, or displaying a check engine light? These are classic signs of a failing Transmission Control Module (TCM). The TCM is the electronic brain of your automatic transmission, responsible for orchestrating every gear change, managing torque converter lockup, and monitoring system health. When it fails, it can leave your powerful truck feeling unpredictable and unreliable. This genuine OEM-quality T42 Transmission Control Module, service part number 24255280, is the definitive solution to restore your truck’s factory performance.
Crucially, this module isn’t just a part in a box. It arrives at your door fully pre-programmed to your truck’s specific Vehicle Identification Number (VIN). This critical step eliminates the need for expensive trips to the dealership for programming, saving you time and money. By loading the latest GM software updates directly onto the module, we ensure it communicates flawlessly with your vehicle’s powertrain control module (PCM) and other systems right out of the box. This plug-and-play solution gets you back on the road faster, with the confidence that your transmission is operating exactly as the manufacturer intended.
From the Diagnostic Bay
We had a 2011 Sierra 1500 come into the shop with the owner convinced his transmission was completely shot. It was slamming into gear and occasionally going into ‘limp mode.’ He was quoted thousands for a full transmission rebuild by another shop. After plugging in our scanner, we saw a handful of solenoid circuit codes and a P0700 (Transmission Control System Malfunction). Instead of tearing down the transmission, we inspected the TCM connectors and wiring first. Finding no issues there, we swapped in a VIN-programmed T42 TCM. After a 15-minute install and clearing the codes, the truck shifted like it just rolled off the assembly line. The owner saved a fortune by correctly diagnosing the electronic failure instead of assuming a mechanical one. The issue was never the transmission itself, but the computer controlling it.
Symptoms of a Failing Sierra 1500 TCM
A faulty TCM can manifest in a variety of ways, from subtle annoyances to critical failures. If you’re experiencing any of the following, it’s highly likely your transmission control module is the culprit:
- ✔ Harsh or Delayed Shifting: The truck may slam into gear, hesitate before shifting, or feel like it’s slipping between gears.
- ✔ Stuck in Limp Mode: The transmission may refuse to shift out of a single gear (often 2nd or 3rd) to prevent further damage.
- ✔ Warning Lights: The Check Engine Light or a specific transmission warning light will illuminate on your dashboard.
- ✔ Diagnostic Trouble Codes (DTCs): Common codes include P0700, which indicates a general transmission fault, as well as specific solenoid codes like P0751, P0756, etc.
- ✔ Poor Fuel Economy: Inefficient shifting and failure to engage torque converter lockup can cause a noticeable drop in MPG.
- ✔ No Communication: In severe cases, a scan tool may be unable to communicate with the TCM, indicating a complete module failure.
- ✔ Erratic Instrument Cluster Behavior: The gear indicator (PRNDL) may not display correctly or may flash.
Plug-and-Play Installation and Compatibility
This module is designed for a straightforward installation. On most 2007-2013 Sierra and Silverado models, the TCM is conveniently located in the engine bay, often next to the battery or under the air cleaner box. The process typically takes less than 30 minutes. Simply disconnect the vehicle’s battery, unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. Once the new module is connected and the battery is reconnected, the vehicle is ready to go. We recommend using a basic scan tool to clear any stored DTCs after installation for a clean slate.
This T42 TCM is a direct replacement for a wide range of GM part numbers, ensuring broad compatibility. It interchanges with service numbers such as 24242391, 24234503, 24252114, 24230461, 24256960, and many more. While it is the specified part for the 2007-2013 GMC Sierra 1500, it also fits an extensive list of other GM vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E, including the Chevrolet Tahoe, Suburban, Express Van, GMC Yukon, and Cadillac DTS.
Frequently Asked Questions
What does ‘VIN Programmed’ mean?
VIN programming means we load your vehicle’s specific identification number and corresponding factory software onto the module before we ship it. This ensures the TCM works perfectly with your truck’s engine, electronics, and options, eliminating the need for dealership programming.
Is this a difficult part to install myself?
For most DIY mechanics, this is a very manageable job. The TCM is typically located in an accessible part of the engine bay. The installation involves disconnecting the battery, unplugging a few connectors, and removing a few bolts. No special tools are required beyond a basic socket set.
Will this fix my P0700 check engine light code?
Yes, if the P0700 code is being triggered by an internal failure of the original TCM, this replacement module is the correct fix. P0700 is a general code indicating the TCM has detected a problem. Replacing the faulty module resolves the root cause.
Do I need to return my old TCM?
No, there is no core charge or requirement to send your old part back. You can keep it or dispose of it at your convenience.
How do I know if this part fits my vehicle?
This module is designed for 2007-2013 GMC Sierra 1500 models and many other GM vehicles from 2006-2014. The best way to confirm is to match your original part number to the list of interchangeable numbers provided. If you are unsure, please contact us with your VIN, and we will verify the fitment for you.