Restore Your Truck’s Shifting Performance
If you’re dealing with the frustration of a transmission that won’t shift correctly in your 2007 GMC Sierra 2500, you’re not alone. As a technician with over two decades of experience, I’ve seen countless work trucks sidelined by what seems like a major transmission failure, but the root cause is often electronic. This VIN-programmed T42 Transmission Control Module (TCM), part number 24234503, is the definitive solution to restore the crisp, reliable shifting your truck had from the factory.
Your TCM is the brain of your automatic transmission, controlling everything from shift points to torque converter lockup. When it fails, you get a cascade of problems that can feel overwhelming. This module is engineered to OEM specifications and arrives pre-loaded with the latest GM software, specifically calibrated to your truck’s Vehicle Identification Number. This eliminates the need for expensive dealership programming, making it a true plug-and-play fix for both professional mechanics and dedicated DIYers.
From the Diagnostic Bay: The Intermittent Shifting Nightmare
I once had a 2007 Sierra 2500 HD in my shop with a problem that was driving the owner crazy. He used it for his contracting business, and it would randomly refuse to shift out of 3rd gear, but only after it was fully warmed up and had been driven for over an hour. We checked for codes, and all we got was a generic P0700 (Transmission Control System Malfunction). We checked the fluid, wiring, and solenoids—everything looked fine. The issue was so intermittent, we couldn’t reliably reproduce it. After ruling out mechanical issues, we focused on the brain. We swapped in one of our pre-programmed T42 TCMs, and the problem vanished instantly. The old module had developed an internal fault that only appeared with heat soak. This replacement part saved him from a potential transmission rebuild and got his work truck back on the job.
Is Your Sierra 2500 Showing These Telltale Signs?
A failing TCM doesn’t always mean a dead transmission. Often, replacing this single component can resolve these common issues. Here’s what to look for:
- âś” Harsh, slamming shifts or erratic gear changes.
- âś” The truck is stuck in “limp mode” (usually 2nd or 3rd gear).
- âś” Check Engine Light is on with transmission-related Diagnostic Trouble Codes (DTCs) like P0700, P0750, or other solenoid-specific codes.
- âś” Delayed engagement when shifting from Park to Drive or Reverse.
- âś” Failure to upshift or downshift, leading to poor acceleration and fuel economy.
- âś” A complete loss of communication with the transmission module.
DIY Installation: A Straightforward Guide
One of the best features of this module is its simple installation. You don’t need a lift or specialized transmission tools. For the 2007 Sierra 2500 TCM, the module is typically located right in the engine bay, making for a quick swap.
- Safety First: Always disconnect the negative terminal from your truck’s battery before starting any electrical work.
- Locate the Module: On your Sierra 2500, the TCM is usually mounted next to the battery in the engine compartment.
- Disconnect the Harnesses: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Do not force them.
- Remove the Old TCM: Unbolt the module from its mounting bracket. It’s typically held on by a few small bolts.
- Install the New Module: Mount your new, pre-programmed TCM in place, re-secure the bolts, and firmly reconnect the electrical harnesses until they click.
- 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 DTCs from the computer’s memory.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for service number 24234503 and is interchangeable with many other part numbers. It is guaranteed to fit the following models, among others:
- GMC SIERRA 2500 PICKUP (2007): new style (smooth door skin), 6.0L, (located next to battery)
- Chevrolet SILVERADO 2500 PICKUP (2007): new style (smooth door skin), 6.0L, (located next to battery)
- GMC Savana / Chevrolet Express Vans (2006-2014): (RH engine compartment)
- Chevrolet Tahoe / GMC Yukon (2007-2009): (next to battery)
- Chevrolet Silverado 1500 / GMC Sierra 1500 (2007-2013): (next to battery)
- Hummer H3 (2008-2010): (RH rear engine compartment)
- …and many other GM cars, trucks, and SUVs from 2006-2014. Please verify fitment with your vehicle.
Do I need to take my truck to the dealership for programming?
Do I need to take my truck to the dealership for programming?
No. This Transmission Control Module comes fully pre-programmed to your vehicle’s specific VIN. This means it is ready for installation right out of the box, saving you time and the high cost of dealership programming.
How difficult is the installation?
For a 2007 Sierra 2500, this is a very straightforward job for a DIYer with basic hand tools. The module is located in an accessible spot in the engine bay, and the entire process typically takes less than 30 minutes.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old module or dispose of it without the hassle of needing to send it back to us.
Will this fix a P0700 code?
A P0700 is a generic code indicating the TCM has detected a fault. In many cases, a failing TCM is the source of this code. Replacing the module with this pre-programmed unit is a very common and effective fix, especially if accompanied by symptoms like erratic shifting.
What kind of warranty is included?
This module is backed by our one-year, hassle-free warranty, giving you peace of mind and confidence in your repair.