Get Your Yukon XL Shifting Smoothly Again
If you’re dealing with the frustrating and unpredictable performance of a failing transmission control module (TCM) in your 2007-2008 GMC Yukon XL 1500, you’ve come to the right place. As a technician with over two decades of experience, I’ve seen firsthand how a faulty TCM can sideline an otherwise perfectly good truck. From jarring shifts that make you cringe to being stuck in limp mode on the side of the road, the symptoms are hard to ignore. This T42 Transmission Control Module, part number 24252114, is the definitive solution to restore your vehicle’s factory performance and reliability.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We pre-program each module to your Yukon’s specific Vehicle Identification Number (VIN) before it ships. This critical step ensures seamless communication between the TCM, the engine, and the transmission, eliminating the need for an expensive trip to the dealership for programming. It’s a true plug-and-play fix designed for both professional mechanics and determined DIYers.
Case Study: A Tricky Diagnosis
A customer brought in his ’08 Yukon XL complaining of intermittent ‘no-shift’ conditions and a check engine light. He’d already replaced a couple of shift solenoids, but the problem persisted. His scan tool showed a generic P0700 (Transmission Control System Malfunction) code, which is more of a signpost than a destination. After checking the wiring harness for damage, we focused on the TCM. In my shop, I’ve seen hundreds of these T42 modules fail due to internal circuit board issues caused by years of heat cycles and vibration. We swapped in a VIN-programmed module, and the truck’s shifting logic was instantly restored. The problem wasn’t the solenoids themselves, but the module’s inability to properly command them. This is a classic scenario where replacing the brain, not just the limbs, is the correct fix.
Is Your Yukon Exhibiting These Transmission Faults?
A failing TCM can manifest in several ways. If you’re noticing any of the following, it’s a strong indicator that your module needs attention. The most common issue I diagnose for a bad 2007-2008 Yukon XL 1500 TCM is erratic shifting behavior that can’t be traced to mechanical failure.
- ✔ Harsh, delayed, or slamming gear changes.
- ✔ The vehicle is stuck in a single gear (often called “limp mode”).
- ✔ Check Engine Light is on with transmission-related Diagnostic Trouble Codes (DTCs) like P0700, P0750, or other solenoid-specific codes.
- ✔ Failure to upshift or downshift correctly, leading to poor acceleration.
- ✔ A noticeable decrease in fuel economy.
- ✔ The transmission seems to slip in and out of gear.
A Straightforward Guide to Installation
One of the best parts of this solution is its simplicity. For the 2007-2008 Yukon XL 1500, the TCM is conveniently located in the engine bay, making for a quick swap that you can do in your own driveway in under 30 minutes.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On your Yukon XL, the TCM is typically mounted right next to the battery. It’s a silver box with several large electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical connectors. There may be locking tabs you need to release. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place. Securely plug in the electrical connectors until they click, ensuring a solid connection.
- Final Steps: Reconnect the negative battery terminal. While the module is plug-and-play, it’s always good practice to use a scan tool to clear any stored DTCs from the vehicle’s memory. Start the engine and take it for a test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 TCM is a direct-fit replacement for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. While this page is focused on the 2007-2008 Yukon XL 1500 TCM, it also fits the following models. Please verify your specific model and options.
- GMC Yukon / Yukon XL 1500: 2007-2008 (located next to battery)
- Chevrolet Tahoe / Suburban 1500: 2007-2008 (located next to battery)
- Chevrolet Silverado 1500 / GMC Sierra 1500: 2007-2013 (new body style, next to battery)
- Chevrolet Avalanche 1500: 2007-2008 (next to battery)
- Cadillac DTS: 2006-2011 (RH front engine compartment)
- Buick Lucerne: 2006-2011 (LH engine compartment)
- 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 do any programming myself?
No. We handle all the programming for you. Simply provide your vehicle’s VIN at checkout, and the module will arrive ready for immediate installation.
Is this a genuine GM part?
This is an OEM-quality module built to the original manufacturer’s specifications for fit, form, and function, ensuring reliable performance and longevity. It is a direct replacement for part number 24252114 and other interchangeable numbers.
What tools do I need for installation?
For most vehicles like the Yukon XL, you’ll only need basic hand tools, such as a socket set to disconnect the battery and unbolt the module. No special diagnostic equipment is required for the installation itself.
What is a core charge?
There is no core charge for this part. You can keep your old module without needing to send it back, saving you time and hassle.
Will this fix a P0700 code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While a failing TCM is a very common cause, this code can also be triggered by other issues. However, if you are also experiencing the shifting symptoms listed above, replacing the TCM is the most likely solution.