If you’re dealing with a transmission that’s acting up in your 2007 GMC Sierra 2500, you know how frustrating it can be. A truck that won’t shift right, gets stuck in gear, or throws a check engine light can bring your workday to a halt. As a technician with over two decades of experience, I’ve seen countless transmission issues that weren’t mechanical failures but rather electronic ones. The Transmission Control Module (TCM) is the brain of your automatic transmission, and when it fails, the symptoms can mimic a much more serious problem.
This T42 Transmission Control Module is the definitive solution for your truck. It’s not just a replacement part; it’s a fully integrated fix. We pre-program it to your truck’s specific Vehicle Identification Number (VIN) before it ships. This means no expensive trips to the dealership for programming—it arrives ready for a true plug-and-play installation. This step is critical for ensuring the TCM communicates flawlessly with your vehicle’s engine computer and other systems, restoring the precise shift points and smooth torque converter lockup your Sierra 2500 was designed for.
From the Diagnostic Bay
I remember a customer bringing in his ’07 Sierra 2500 HD with the 6.0L. The truck was stuck in what he called ‘get-home mode,’ and another shop had quoted him over $4,000 for a transmission rebuild. He was understandably stressed. I hooked up my scan tool and saw a few solenoid performance codes and the classic P0700 (Transmission Control System Malfunction). Instead of jumping to conclusions, I checked the TCM’s communication. It was intermittent. We swapped in a VIN-programmed TCM, cleared the codes, and took it for a test drive. It shifted perfectly. The customer saved thousands and drove away with a reliable truck, all because we addressed the electronic root cause, not just the symptoms.
Why a Programmed 2007 Sierra 2500 TCM is the Smart Fix
Choosing a pre-programmed module is the most efficient way to get your truck back to factory performance. The T42 TCM directly manages hydraulic pressure, shift solenoid activation, and transmission diagnostics. A failing unit can cause poor fuel economy, transmission overheating, and even leave you stranded. Our module, loaded with the latest GM software updates for your specific VIN, ensures all these functions operate in perfect harmony from the moment you install it.
Is Your Sierra Exhibiting These Telltale Signs?
- âś” Harsh, erratic, or delayed gear shifts.
- âś” Vehicle is stuck in limp mode (often 2nd or 3rd gear).
- âś” Check Engine Light or Transmission Warning Light is on.
- âś” Diagnostic Trouble Codes (DTCs) like P0700, P0750, or other solenoid-related faults are present.
- âś” The transmission refuses to upshift or downshift correctly.
- âś” A noticeable drop in fuel efficiency or signs of the transmission running hot.
- âś” Complete loss of communication with the scan tool or intermittent electrical problems.
A Straightforward Guide to Installation
- âś” 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.
- âś” Locate the Module: On your 2007 Sierra 2500, the TCM is typically located in the engine compartment, right next to the battery. It’s a silver box with electrical connectors.
- âś” Disconnect and Remove: Carefully unclip the wiring harness connectors. Then, unbolt the module from its mounting bracket. Keep the hardware in a safe place.
- âś” Install the New TCM: Mount the new, pre-programmed TCM onto the bracket and securely tighten the bolts. Reconnect the wiring harnesses, ensuring they click into place.
- âś” Final Steps: Reconnect the battery terminal. Start the truck and let it idle for a few minutes. If you have a scan tool, it’s good practice to clear any stored DTCs. Test drive the vehicle to confirm smooth shifting.
Verified Vehicle Compatibility
This module is a direct replacement for part number 24235753 and other interchangeable numbers. While this page is focused on the 2007 Sierra 2500, this T42 TCM also fits a wide range of GM vehicles from 2006-2014, including:
- GMC Sierra / Yukon / Savana
- Chevrolet Silverado / Tahoe / Suburban / Express / Colorado
- Cadillac DTS
- Hummer H3
- Buick LaCrosse / Lucerne
- Pontiac G6 / Grand Prix
- And many others. Please verify the fitment list for your specific model and year.
Do I need to have this module programmed by a dealer?
Do I need to have this module programmed by a dealer?
No. We handle all the programming for you. Simply provide your vehicle’s VIN during checkout, and the module will arrive ready for plug-and-play installation, saving you time and money.
What is a VIN and where do I find it?
The VIN (Vehicle Identification Number) is a unique 17-digit code for your truck. You can find it on the driver’s side dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Will this fix a P0700 trouble code?
A P0700 code is a general fault message indicating the TCM has detected a problem. While this module often resolves the root cause of a P0700, it’s important to have the specific transmission codes (e.g., P07xx) to confirm the diagnosis. A failing TCM is a very common cause.
Is there a core charge for this part?
No, there is no core charge. You are not required to send your old, faulty module back to us, which simplifies the repair process for you.
How difficult is the installation?
For most DIYers with basic tools, this is a straightforward job that can be completed in under 30 minutes. The module is easily accessible in the engine bay on most trucks.