If your GMC Sierra is plagued by erratic shifting, getting stuck in gear, or a persistent check engine light, you’re likely dealing with a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless GM trucks come into the shop with these exact issues. The TCM is the electronic brain of your automatic transmission, and when it falters, it can make your reliable truck feel unpredictable and unsafe. This isn’t just an annoyance; it’s a critical failure that impacts performance, fuel economy, and drivability.
This T42 Transmission Control Module is the definitive solution for your 2007-2013 Sierra 1500 and a wide range of other GM vehicles. The most significant benefit we offer is the pre-shipment VIN programming. We flash the module with your truck’s specific Vehicle Identification Number and the latest GM software updates. This means it arrives at your door ready for a true plug-and-play installation, completely bypassing the need for an expensive trip to the dealership for programming. You get a reliable fix that restores factory-perfect shifting logic without the extra cost or hassle.
A Technician’s Notebook
I remember a 2011 Sierra 1500 that came in on a tow truck. The owner was frustrated because it would intermittently refuse to shift out of 3rd gear (limp mode) and had a P0700 code that wouldn’t stay cleared. He’d already replaced a shift solenoid with no luck. After a quick diagnostic, we confirmed the TCM was the culprit. These T42 modules, especially after years of heat cycles in the engine bay, can develop internal circuit failures that cause these ghost-in-the-machine problems. We installed one of our pre-programmed modules, and in under 30 minutes, the truck was shifting perfectly. The customer saved hundreds compared to the dealer quote and drove away with a truck that felt brand new again. This is the kind of straightforward, effective repair we aim to provide.
Is Your Sierra Exhibiting These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission breakdown. Often, the symptoms start small and get progressively worse. If you’re noticing any of the following, it’s a strong indicator that your 2007-2013 Sierra 1500 TCM is the source of the problem.
- âś” Hard, slamming shifts between gears or delayed engagement from park to drive.
- âś” The vehicle is stuck in ‘limp mode,’ often refusing to shift past 2nd or 3rd gear.
- âś” An illuminated Check Engine Light or Transmission Warning Light, with stored Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults.
- âś” Complete loss of upshifting or downshifting capabilities.
- âś” A noticeable drop in fuel efficiency or signs of the transmission overheating.
- âś” Intermittent communication loss with the module, causing unpredictable behavior.
A Straightforward Guide to Your TCM Swap
One of the best parts about this repair is its simplicity. For most DIYers or professional mechanics, this is a quick job that requires basic hand tools and less than 30 minutes of your time.
- Safety First: Always disconnect the negative terminal from your truck’s battery to prevent any electrical shorts and to help reset the vehicle’s adaptive memory.
- Locate the Module: On the 2007-2013 Sierra 1500, the TCM is typically located in the engine compartment, right next to the battery. It’s a silver box with several large electrical connectors.
- Disconnect and Remove: Carefully unplug the wiring harnesses. They have locking tabs, so be gentle. Once disconnected, unbolt the module from its mounting bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place. Securely plug in the wiring harnesses, ensuring they click to confirm a solid connection.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s good practice to use a basic OBD2 scan tool to clear any lingering fault codes from the vehicle’s memory. Start the truck and enjoy smooth shifting!
Verified Vehicle Compatibility List
This T42 TCM is a direct-fit replacement for a wide array of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. While this page focuses on the 2007-2013 Sierra 1500 TCM, it is also compatible with the following models. Please verify your specific model and location notes.
Primary Fitment: GMC & Chevrolet Trucks/SUVs
- âś” GMC Sierra 1500 Pickup: 2007 (New Body Style), 2008, 2009-2013 (w/o hybrid) – Located next to battery.
- âś” Chevrolet Silverado 1500 Pickup: 2007 (New Body Style), 2008, 2009-2013 (w/o hybrid) – Located next to battery.
- âś” GMC Yukon / Yukon XL 1500: 2007-2009 – Located next to battery.
- âś” Chevrolet Tahoe / Suburban 1500: 2007-2009 – Located next to battery.
- âś” Chevrolet Avalanche 1500: 2007-2008 – Located next to battery.
Additional GM Vehicle Fitment (Partial List):
- âś” Chevrolet Colorado / GMC Canyon: 2008-2012
- âś” Chevrolet Express / GMC Savana Vans: 2006-2014
- âś” Hummer H3: 2008-2010
- âś” Buick LaCrosse / Lucerne: 2006-2011
- âś” Cadillac DTS: 2006-2011
- âś” Pontiac G6 / Grand Prix: 2006-2010
- âś” And many more. This module interchanges with part numbers: 24252114, 24234503, 24230461, 24234274, 24256960, and YNXS.
Frequently Asked Questions
Do I need to take my truck to the dealer after installing this TCM?
No. This is the biggest advantage of our service. We pre-program the module to your vehicle’s specific VIN before shipping. This means it is ready for installation right out of the box, with no additional programming or dealer visits required.
What information do you need to program the module?
We require your 17-digit Vehicle Identification Number (VIN) at checkout. This ensures we load the correct factory software for your truck’s specific configuration, guaranteeing seamless communication and performance.
Is this a difficult part for a DIYer to install?
Not at all. For the GMC Sierra 1500, the TCM is easily accessible in the engine bay. With basic hand tools, most people can complete the swap in under 30 minutes. Just locate the old module, disconnect the battery, unplug the harnesses, swap the part, and reconnect everything.
Will this fix a P0700 trouble code?
A P0700 code is a generic fault code indicating the TCM has detected a problem. While this module often resolves the root cause (like a failed internal driver circuit that triggers other codes), you should always diagnose any other potential issues. However, if the TCM itself is faulty, replacing it is the correct fix.
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 at your convenience without the hassle of shipping it back to us.