Is Your Yukon XL Shifting Erratically? Get a Permanent Fix.
If you’re dealing with unpredictable shifting, a check engine light that won’t go away, or your 2007-2008 GMC Yukon XL 1500 suddenly going into limp mode, the problem is very likely a failing Transmission Control Module (TCM). As the electronic brain of your 4L60E, 4L65E, or 4L70E transmission, the TCM dictates every gear change. When it fails, it can make your reliable SUV feel unsafe and unpredictable. This isn’t just an annoyance; it’s a critical component for your vehicle’s performance and your peace of mind on the road.
This OEM-quality T42 TCM, part number 24256960, is the definitive solution. We pre-program it to your vehicle’s specific VIN, so it arrives ready for a true plug-and-play installation. Forget about expensive dealership visits for programming—this module is designed to get you back on the road quickly and affordably, restoring the smooth, reliable performance you expect from your GMC.
A Technician’s Notebook: The Intermittent Limp Mode Mystery
I once had a 2008 Yukon XL in my bay with a frustrating problem. The owner said it would randomly drop into limp mode (stuck in 3rd gear) on his commute, but only on hot days. He’d already replaced two shift solenoids at another shop with no success. After hooking up my scan tool and monitoring live data, I noticed the TCM was intermittently losing communication right as the transmission temperature climbed. The module, located next to the battery, was getting heat-soaked and the internal circuits were failing. We installed a VIN-programmed 2007-2008 Yukon XL 1500 TCM, and the problem was solved permanently. It’s a classic failure mode for these T42 modules, and a direct replacement is the only reliable fix.
Common Signs of a Failing GM T42 Module
A faulty TCM can cause a wide range of transmission issues. If your vehicle is exhibiting any of these behaviors, it’s time to consider a replacement. Here are the most common symptoms I see in my shop:
- âś” Harsh, banging shifts or delayed gear engagement.
- âś” Vehicle is stuck in one gear (often called “limp mode”).
- âś” The check engine light is on with transmission-related codes like P0700, P0750, P0753, or other solenoid circuit faults.
- âś” Failure to upshift or downshift properly, leading to poor acceleration.
- âś” A noticeable drop in fuel economy due to inefficient shifting.
- âś” The transmission seems to slip between gears.
DIY-Friendly Installation in Under 30 Minutes
Replacing the 2007-2008 Yukon XL 1500 TCM is a straightforward job that most DIYers can handle with basic tools. Because our module comes pre-programmed, you eliminate the most complicated step. Just follow this simple process:
- 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 located in the engine bay, right next to the battery. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses. Ensure they click into place.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the vehicle and check for any warning lights. We recommend using a basic OBD2 scanner to clear any stored fault codes after installation.
Verified Fitment for Your General Motors Vehicle
This T42 Transmission Control Module is a direct replacement for part number 24256960 and is compatible with a wide range of GM vehicles equipped with 4-speed automatic transmissions. While this page is focused on the Yukon XL, please verify your specific model and year below. This module interchanges with part numbers including 24242391, 24234503, 24252114, and others.
Partial Fitment List:
- GMC YUKON XL 1500: 2007-2008 (Transmission; next to battery)
- Chevrolet Tahoe / Suburban 1500: 2007-2008 (Transmission; next to battery)
- GMC Sierra 1500 / Chevrolet Silverado 1500: 2007-2013 (New style, next to battery)
- Cadillac DTS: 2006-2011 (RH front engine compartment)
- Buick LaCrosse / Allure: 2006-2009 (Lower air cleaner housing)
- Chevrolet Impala: 2006-2011 (Lower air cleaner housing)
- Hummer H3: 2008-2010 (RH rear engine compartment)
- …and many more GM models from 2006-2014.
Frequently Asked Questions
Do I need to have this module programmed by a dealer?
No. This module is delivered to you pre-programmed to your vehicle’s VIN. It is ready for installation right out of the box, saving you time and money.
What is a core charge?
A core charge is a deposit that is refunded when you return your old part. We do not require a core charge for this TCM, so you can keep your old part without any hassle.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault request from the TCM to the ECM to turn on the check engine light. While this module often resolves the underlying issue causing the P0700, you should scan for more specific P-codes (like P0753) to confirm the diagnosis. A failing TCM is a very common cause.
Where is the TCM located on my 2007 Yukon XL 1500?
On the 2007-2008 GMC Yukon XL 1500, the Transmission Control Module is located in the engine compartment, mounted right next to the battery.
What is the warranty on this part?
This part comes with a one-year warranty, ensuring it meets our high standards for quality and reliability for your daily driving needs.