Is Your Sierra 2500’s Transmission Giving You Headaches?
If you’re dealing with a 2007 GMC Sierra 2500 that’s shifting harshly, getting stuck in gear, or throwing a check engine light, a faulty Transmission Control Module (TCM) is the most likely culprit. As the central computer for your 4L80E transmission, the T42 TCM dictates every shift, manages torque converter lockup, and monitors performance. When it fails, it can make your reliable workhorse feel unpredictable and unsafe. Stop throwing money at fluid changes or solenoid replacements that don’t solve the core electronic issue.
This is a direct-replacement, OEM-quality T42 Transmission Control Module, part number 24256960. The most significant benefit we offer is that it arrives at your door fully programmed to your truck’s specific Vehicle Identification Number (VIN). This means you can skip the expensive trip to the dealership for programming. It’s a true plug-and-play solution designed for both professional technicians and DIY-savvy truck owners who want a reliable fix without the hassle.
From the Diagnostic Bay: The “Bad Transmission” That Wasn’t
A customer brought in his ’07 Sierra 2500 HD with the 6.0L, complaining of violent 1-2 shifts and getting stuck in 3rd gear (limp mode). He’d been quoted over $3,000 for a transmission rebuild at another shop. I hooked up my scanner and immediately saw a P0700 code and several solenoid circuit faults. In my 20+ years of experience, seeing multiple, intermittent solenoid codes at once rarely points to the solenoids themselves. It’s almost always the module commanding them. We ordered one of these VIN-programmed TCMs, installed it in about 15 minutes right next to the battery, cleared the codes, and the truck shifted like it just rolled off the factory floor. The customer saved thousands and was back on the road the same day. This is a classic T42 TCM failure scenario.
Is Your Sierra Exhibiting These Transmission Faults?
A failing TCM can manifest in several ways. If you’re experiencing any of the following, this module is the likely solution for your 2007 Sierra 2500 TCM issues:
- âś” Harsh, banging, or erratic gear shifts.
- âś” Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- âś” Check Engine Light or Transmission Warning Light is on.
- âś” Diagnostic Trouble Codes (DTCs) like P0700, P0750, P0753, P0758, or other solenoid-related codes are present.
- âś” Delayed engagement when shifting from Park to Drive or Reverse.
- âś” Failure to upshift or downshift properly.
- âś” Poor fuel economy and a feeling of sluggish performance.
A Straightforward Guide to Installation
You don’t need to be a master mechanic to replace this module. The entire process typically takes less than 30 minutes with basic hand tools.
- Safety First: 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 TCM: On your 2007 Sierra 2500, the TCM is conveniently located in the engine bay, mounted in a bracket right next to the battery.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs, so be gentle. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses. You should hear a click as they lock in.
- Final Steps: Reconnect the negative battery terminal. While the module is plug-and-play, it’s best practice to use a basic OBD2 scan tool to clear any stored fault codes from the system. Start the vehicle and test drive to confirm smooth shifting.
Verified Fitment for Your GM Vehicle
While this is a perfect solution for the 2007 Sierra 2500 TCM, this module is also compatible with a wide range of GM cars, trucks, and SUVs. Please verify your model and options below. This part is interchangeable with service numbers 24242391, 24234503, 24252114, 24256960, and others.
This part will fit these makes and models with these options
SAVANA 3500 VAN 06-14 Transmission; (RH engine compartment)
SIERRA 2500 PICKUP 07 Transmission; new style (smooth door skin), 6.0L, (next to battery)
SILVERADO 2500 PICKUP 07 Transmission; new style (smooth door skin), 6.0L, (next to battery)
TAHOE 07 Transmission; (next to battery)
YUKON 07 Transmission; (next to battery)
EXPRESS 3500 VAN 06-14 Transmission; (RH engine compartment)
SAVANA 2500 VAN 06-14 Transmission; (RH engine compartment)
EXPRESS 2500 VAN 06-14 Transmission; (RH engine compartment)
SAVANA 1500 VAN 06-14 Transmission; (RH engine compartment)
EXPRESS 1500 VAN 06-14 Transmission; (RH engine compartment)
And many more models including Silverado, Suburban, Yukon XL, Envoy, Trailblazer, Impala, Cobalt, HHR, and others from 2006-2014.
Frequently Asked Questions
Do I need to program this module?
No. This module comes 100% pre-programmed to your vehicle’s VIN. It is ready for installation right out of the box, saving you a trip to the dealership.
Will this fix a P0700 transmission code?
In many cases, yes. The P0700 code is a general fault code requested by the TCM. When the TCM itself is failing, it often sets this code along with more specific solenoid or communication codes. Replacing a faulty TCM is a common fix for a P0700.
Is there a core charge for my old part?
No, there is absolutely no core charge. You can keep your old part or dispose of it without the hassle of sending it back.
Where do I provide my VIN?
You will be prompted to enter your vehicle’s 17-digit VIN during the checkout process. This is crucial for us to program the module correctly for your specific truck.
What is the warranty on this part?
This transmission control module is backed by our comprehensive one-year warranty, giving you peace of mind with your purchase.