If your 2007-2008 GMC Yukon XL 1500 is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, you’re not just dealing with an annoyance—you’re facing a potential breakdown. As a technician with over two decades of experience under the hood, I’ve seen countless GM trucks and SUVs sidelined by a faulty Transmission Control Module (TCM). The TCM is the brain of your automatic transmission, and when it fails, the symptoms can range from poor fuel economy to a vehicle that won’t shift at all.
This T42 TCM, part number 24239926, is the definitive solution. We take the guesswork and dealership hassle out of the equation. Each module is expertly programmed to your vehicle’s specific VIN before it ships, ensuring it communicates flawlessly with your Yukon’s powertrain right out of the box. This isn’t just a replacement part; it’s a restoration of your vehicle’s original, smooth-shifting performance and reliability.
Case Study: A Tricky Diagnosis
A customer brought in their ’07 Yukon XL 1500 with a frustrating, intermittent problem. It would occasionally refuse to shift out of 3rd gear (limp mode) but only after driving for 20+ minutes. No check engine light was on, but a deep scan showed a stored history code for P0752 (Shift Solenoid A Stuck On). We tested the solenoids and wiring, which all checked out fine. After years of diagnosing these GM platforms, I suspected the TCM was failing under heat. We installed one of our pre-programmed T42 modules, and the problem was solved instantly. The customer saved hundreds by avoiding a dealership’s diagnostic fees and programming costs.
Is Your Yukon Exhibiting These Telltale Signs?
A failing TCM often gives clear warnings. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement:
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ The vehicle is stuck in a single gear (often called “limp mode”).
- ✔ Check Engine Light or Transmission Warning Light is illuminated with codes like P0700, P0750, P0752, or other solenoid-related faults.
- ✔ Inability to upshift or downshift, leading to poor acceleration and terrible fuel mileage.
- ✔ The transmission seems to slip between gears or feels unresponsive.
- ✔ Intermittent loss of communication with the scan tool or other modules.
Your 30-Minute Path Back to Smooth Shifting
One of the best features of this part is the straightforward installation. For the DIY mechanic, this is a job you can complete with basic hand tools in your own driveway. On most 2007-2008 Yukon XL 1500 models, the TCM is easy to access.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and help reset the system.
- Locate the Module: On your Yukon XL, the TCM is typically found in the engine compartment, mounted next to the battery.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place. Reconnect the electrical connectors, ensuring they click securely into position.
- Final Steps: Reconnect the battery terminal. While our programming handles the critical setup, it’s good practice to use a basic scan tool to clear any old fault codes from the vehicle’s memory. Start the engine and enjoy a test drive with crisp, correct shifting.
Why Choose a Pre-Programmed 2007-2008 Yukon XL 1500 TCM?
This module isn’t just a part; it’s a complete repair solution. Built to strict OEM specifications and backed by a one-year warranty, it provides the durability and performance you need. By programming it with the latest GM software updates tied to your VIN, we ensure it corrects common factory software issues and optimizes performance for your specific vehicle, eliminating the need for an expensive trip to the dealer for programming.
Verified Fitment For These General Motors Vehicles
This T42 TCM is a direct replacement for part number 24239926 and other interchangeable numbers. While this page focuses on the Yukon XL, it is compatible with a wide range of GM vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. Please verify your specific model below:
- GMC Yukon XL 1500 (2007-2008): Transmission; (next to battery)
- Chevrolet Avalanche 1500 (2007-2008): Transmission; (next to battery)
- Chevrolet Silverado 1500 (2007-2013): See specific options in fitment data.
- Chevrolet Suburban 1500 (2007-2008): Transmission; (next to battery)
- Chevrolet Tahoe (2007-2009): See specific options in fitment data.
- GMC Sierra 1500 (2007-2013): See specific options in fitment data.
- GMC Yukon (2007-2009): See specific options in fitment data.
- …and many other GM cars, trucks, and SUVs from 2006-2014. Please consult the full fitment list.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
It means we load the module with the specific software and calibration file from General Motors that matches your vehicle’s 17-digit Vehicle Identification Number (VIN). This makes the part plug-and-play, as it’s already configured to communicate correctly with your Yukon’s engine and other systems, just like a new part from the dealership.
Will this fix my ‘limp mode’ problem?
In the vast majority of cases, yes. Limp mode (being stuck in 2nd or 3rd gear) is the most common symptom of a failed TCM on these GM vehicles. If you have confirmed your transmission’s mechanical parts are in good condition, replacing the TCM is the most likely fix.
Do I need any special tools for this installation?
No special tools are required. A basic socket set to remove the mounting bolts and a flathead screwdriver to help with the connector tabs are typically all you need. The entire process should take less than 30 minutes for most DIYers.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old part, so you don’t have to worry about the cost or hassle of shipping it back to us.
How do I provide my VIN?
You will be prompted to enter your vehicle’s VIN during the checkout process. Please double-check it for accuracy, as the programming is specific to this number.