Restore Flawless Shifting to Your GMC Yukon XL 1500
If you’re dealing with the frustration of a transmission that bangs into gear, refuses to shift, or has put your 2007-2008 Yukon XL 1500 into limp mode, you’ve come to the right place. As a technician with over two decades of experience under the hood, I’ve seen countless drivers worry they need a full transmission rebuild when the real culprit is a faulty Transmission Control Module (TCM). This T42 series TCM, part number 24240449, is the definitive solution to restore the crisp, predictable shifting your GM truck or SUV was built for.
Case Study: A Tricky Diagnosis
A customer brought in their ’08 Yukon XL, convinced the transmission was shot. It was stuck in 3rd gear (limp mode), the check engine light was on, and it shifted so harshly it felt like being rear-ended. They were quoted over $3,000 for a transmission replacement at another shop. I hooked up my scan tool and saw a P0700 (Transmission Control System Malfunction) and a few solenoid circuit codes. Before condemning the transmission, I checked the TCM. Sure enough, after swapping in one of our VIN-programmed modules—a 30-minute job right next to the battery—all the codes cleared and the truck shifted like it just rolled off the factory floor. It’s a fix that saved the customer thousands and highlights why you should always check the electronics first.
Is Your Yukon XL Exhibiting These Telltale Signs?
A failing TCM doesn’t hide its symptoms well. If you’re noticing any of the following, this module is very likely the component you need to replace. Over the years, I’ve found these are the most common indicators of a T42 TCM failure:
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ Your vehicle is stuck in a single gear, often called “limp mode,” to protect the transmission.
- ✔ The Check Engine Light or a specific transmission warning light is illuminated on your dash.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔ Inconsistent or no shifting, leading to poor acceleration and terrible fuel economy.
- ✔ The transmission seems to slip between gears or fails to engage from Park to Drive or Reverse.
The Smart Solution: A Programmed 2007-2008 Yukon XL 1500 TCM
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We handle the complex part—the programming—so you can get your vehicle back to perfect working order without a trip to the dealership. It’s built to meet or exceed original equipment specifications for a long service life.
Your 30-Minute Path to Smooth Shifting
One of the best parts about this repair is its simplicity. You don’t need a vehicle lift or specialized transmission tools. For most GMT900 platform trucks like your Yukon XL, the process is straightforward.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electronic component replacement.
- Locate the TCM: On your 2007-2008 Yukon XL 1500, the TCM is conveniently located in the engine bay, right next to the battery.
- Disconnect and Remove: Carefully unclip the wiring harness connectors. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place and securely reconnect the wiring harnesses. You’ll hear a click as they lock in.
- Final Steps: Reconnect the battery terminal. Start the vehicle and use a basic OBD2 scan tool to clear any stored fault codes. Take it for a test drive to confirm the smooth shifting performance.
Verified Fitment for Your General Motors Vehicle
While this page focuses on the 2007-2008 Yukon XL 1500, this T42 TCM is compatible with a wide range of GM vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. Please verify your model and location below. This part is a direct replacement for service numbers 24242391, 24234503, 24252114, 24240449, and more.
YUKON XL 1500 07-08 Transmission; (next to battery)
TAHOE 07-09 Transmission; (next to battery), check options
SILVERADO 1500 PICKUP 07-13 Transmission; (next to battery), check options
SIERRA 1500 PICKUP 07-13 Transmission; (next to battery), check options
SUBURBAN 1500 07-08 Transmission; (next to battery)
AVALANCHE 1500 07-08 Transmission; (next to battery)
EXPRESS 1500/2500/3500 VAN 06-14 Transmission; (RH engine compartment)
SAVANA 1500/2500/3500 VAN 06-14 Transmission; (RH engine compartment)
…and many more GM cars, trucks, and SUVs from 2006-2014.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
What does ‘VIN Programmed’ actually mean?
It means we load your vehicle’s unique 17-digit Vehicle Identification Number (VIN) and the latest GM software onto the module before we ship it. This ensures it communicates perfectly with your vehicle’s other computers (like the ECM and BCM) right out of the box, eliminating the need for expensive dealership programming.
Can I install this 2007-2008 Yukon XL 1500 TCM myself?
Absolutely. This is a very popular repair for DIY mechanics. The module is typically located next to the battery in the engine bay, requiring only basic hand tools to swap out. The entire process usually takes less than 30 minutes.
Will this fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. In many cases, a failing TCM is the root cause, and replacing it will resolve the P0700 and any related solenoid codes. However, you should always ensure the transmission fluid is clean and at the correct level first.
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 shipping it back to us, simplifying your repair process.