If your 2007-2009 GMC Yukon is suffering from jarring shifts, getting stuck in gear, or throwing transmission codes, the problem is very likely a failing Transmission Control Module (TCM). As the electronic brain of your automatic transmission, a faulty TCM can make your reliable SUV feel unpredictable and unsafe. I’ve seen it hundreds of times in the shop: a perfectly good transmission crippled by a failing computer. This T42 TCM, part number 24243901, is the definitive solution, arriving at your door fully programmed to your vehicle’s VIN for a true plug-and-play repair.
Forget about expensive dealership visits and the hassle of scheduling a programming appointment. We handle the critical software flashing for you. Using the latest GM updates, we ensure this module communicates flawlessly with your Yukon’s engine computer and other systems right out of the box. This restores precise shift commands, proper torque converter lockup, and accurate diagnostic feedback, bringing back the smooth, confident performance you expect from your vehicle.
A Technician’s Notebook
A customer brought in a 2008 Yukon XL with a complaint that stumped two other shops. The vehicle would randomly refuse to shift out of 2nd gear, but only after driving for 30+ minutes on a hot day. There were no consistent solenoid codes, just a general P0700 (Transmission Control System Malfunction). After checking the wiring and fluid, I suspected the TCM. On these GM trucks, the TCM is often mounted right next to the battery in the hot engine bay. Over years, heat cycles can cause internal circuit board failures that only appear when the module gets hot. We installed one of our pre-programmed TCMs, and the problem was solved instantly. It’s a classic case where the component itself is the root cause of an elusive, intermittent issue.
Is Your Yukon Exhibiting These Telltale Signs?
A failing TCM will give you clear warnings. If you’re experiencing any of the following, it’s time for a replacement:
- ✔ Harsh, slamming shifts or erratic gear hunting.
- ✔ The vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ Check Engine Light or Transmission Warning Light is on with codes like P0700, P0750, or other solenoid-related DTCs.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ Complete failure to upshift or downshift.
- ✔ A noticeable drop in fuel economy or signs of the transmission overheating.
A Straightforward Guide to Installation
Replacing the 2007-2009 Yukon TCM is a job most DIYers can handle in their driveway in under 30 minutes. The location can vary slightly, but on most Yukons, Tahoes, and Sierras of this era, you’ll find it right next to the battery.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the system.
- Locate the Module: Find the TCM, typically a silver box with large electrical connectors, mounted near the battery or under the air cleaner box.
- Disconnect and Remove: Carefully unclip the wiring harnesses. They have locking tabs, so be gentle. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place. Securely reconnect the wiring harnesses, ensuring they click into place.
- Final Steps: Reconnect the negative battery terminal. While our programming handles the heavy lifting, it’s good practice to use a basic scan tool to clear any stored DTCs from the vehicle’s memory. Start the vehicle and enjoy your smooth-shifting transmission!
Verified Fitment for Your General Motors Vehicle
This T42 TCM is a direct replacement for a wide range of GM cars, trucks, and SUVs equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. It is interchangeable with part numbers 24252114, 24234503, 24243901, and more. Please verify your model and year from the list below:
- GMC Yukon / Yukon XL 1500 (2007-2009)
- Chevrolet Tahoe / Suburban 1500 / Avalanche 1500 (2007-2008)
- GMC Sierra 1500 / Chevrolet Silverado 1500 (2007-2013)
- Cadillac DTS (2006-2011)
- Hummer H3 (2008-2010)
- Chevrolet Impala (2006-2011)
- Buick LaCrosse / Lucerne (2006-2011)
- Pontiac G6 / Grand Prix (2006-2010)
- …and many other GM models from 2006-2014. See the full fitment list for details.
Frequently Asked Questions
Do I need to take my vehicle to a dealer for programming?
No. This module comes fully programmed to your vehicle’s specific VIN. It is ready for installation right out of the box, saving you time and money.
Will this fix my transmission codes like P0700?
Yes, in most cases. A P0700 code indicates a general fault requested by the TCM. If the TCM itself is the faulty component, replacing it with this programmed unit will resolve the root cause of the code.
Is this a difficult part to install myself?
Not at all. For most vehicle owners with basic hand tools, this is a very straightforward repair that takes less than 30 minutes. The most common location is right next to the battery in the engine bay.
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 returning it.
What transmissions is this module compatible with?
This T42 TCM is designed for vehicles with GM 4-speed automatic transmissions, including the popular 4L60E, 4L65E, 4L70E, and 4L80E.