End Your Yukon’s Transmission Troubles for Good
If you’re dealing with a 2007 or 2008 GMC Yukon XL 1500 that’s shifting erratically, getting stuck in gear, or throwing transmission codes, the culprit is very often a failing Transmission Control Module (TCM). After more than two decades in the garage, I’ve seen countless GM trucks and SUVs sidelined by this exact issue. The TCM is the brain of your automatic transmission, and when it starts to fail, it can cause a cascade of frustrating and potentially damaging problems. This isn’t just an annoyance; it’s a reliability issue that needs a definitive solution.
This OEM-quality T42 TCM, part number YNXS, is the reliable fix you need. We take the guesswork and extra cost out of the repair by pre-programming it to your Yukon’s specific Vehicle Identification Number (VIN). This means it arrives ready for a true plug-and-play installation, restoring the crisp, predictable shifting you expect from your vehicle without a mandatory and expensive trip to the dealership for programming.
Case Study: The Ghost in the Transmission
A customer brought in his ’07 Yukon XL 1500 with a perplexing issue. He said it would randomly refuse to shift out of 3rd gear, but only after driving for 20+ minutes. The check engine light was on, but the codes were for a shift solenoid. He had already replaced the solenoid twice at another shop. I suspected the TCM. In my experience, heat-soaked T42 modules can develop internal faults that send false signals, making you chase phantom mechanical problems. We installed a VIN-programmed TCM, and the problem vanished instantly. It’s a classic scenario where the root cause is electronic, not mechanical, and this part is the direct fix.
Is Your Yukon Exhibiting These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission failure. Often, the signs are intermittent at first. If you’re noticing any of the following, it’s time to inspect your module.
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ The vehicle is stuck in “limp mode” (usually 2nd or 3rd gear) to protect the transmission.
- ✔ Check Engine Light or Transmission Warning Light is illuminated with Diagnostic Trouble Codes (DTCs) like P0700 (Transmission Control System Malfunction) or various P07xx solenoid codes.
- ✔ Inability to upshift or downshift, leading to poor acceleration and terrible fuel economy.
- ✔ Unexplained loss of communication with the TCM when checked with a scan tool.
A Straightforward Guide to Installation
For the 2007-2008 Yukon XL 1500, this is a job most DIYers can handle in their own driveway in under 30 minutes. The module is easy to access.
- Safety First: Always disconnect the negative terminal on your vehicle’s battery before beginning any electronic work.
- Locate the TCM: On your Yukon XL 1500, 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 wiring harnesses. They have locking tabs that need to be released. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the wiring harnesses. You should hear a click as they lock in.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s best practice to use a basic OBD2 scan tool to clear any stored fault codes from the vehicle’s memory to ensure a clean slate.
Why Choose a Pre-Programmed 2007-2008 Yukon XL 1500 Transmission Control Module?
This isn’t just a replacement part; it’s a complete solution. By programming the module to your VIN before it ships, we ensure it has the latest GM software and is perfectly calibrated for your vehicle’s specific 4L60E, 4L65E, or 4L70E transmission. This eliminates compatibility errors and provides a lasting repair that restores performance and efficiency.
Verified Vehicle Compatibility
This T42 TCM (YNXS) is a direct replacement for a wide range of General Motors vehicles. While this page focuses on the Yukon XL 1500, it is also compatible with the following models. Please verify your vehicle’s location, as it can vary.
- GMC Yukon XL 1500 (2007-2008): Transmission; (next to battery)
- Chevrolet Tahoe (2007-2009): Transmission; (next to battery)
- GMC Sierra 1500 (2007-2013): Transmission; (next to battery)
- Chevrolet Silverado 1500 (2007-2013): Transmission; (next to battery)
- Chevrolet Suburban 1500 (2007-2008): Transmission; (next to battery)
- GMC Savana & Chevrolet Express Vans (2006-2014): Transmission; (RH engine compartment)
- …and many other GM cars, trucks, and SUVs from 2006-2014.
Frequently Asked Questions
Do I need to have the dealer program this module?
No. This module is delivered fully programmed to your vehicle’s VIN. It is ready for installation right out of the box, saving you time and money.
What tools are required for installation on my Yukon XL?
You’ll typically only need basic hand tools, such as a socket set to remove the battery terminal and the bolts holding the TCM bracket. A flathead screwdriver may be helpful for releasing the connector tabs.
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.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission system fault code, often triggered by a failing TCM. While this module is the most common solution for that code and related shifting issues, you should always ensure other potential causes (like wiring or sensors) have been ruled out.
What is the warranty on this part?
This part comes with our standard one-year warranty, covering you against any defects for peace of mind.