Restore Peak Performance to Your GMC Yukon’s Transmission
If you’re dealing with the frustration of a GMC Yukon that shifts harshly, gets stuck in gear, or has a persistent check engine light, the problem often lies with a faulty Transmission Control Module (TCM). As a seasoned technician, I’ve seen countless drivers worry about expensive transmission rebuilds when the real culprit is this electronic component. This OEM-quality T42 Transmission Control Module, corresponding to part number 24243921, is the definitive solution for your 2007-2009 GMC Yukon, restoring the smooth, reliable performance you depend on.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We pre-program each module to your vehicle’s specific VIN, ensuring it communicates flawlessly with your engine computer and transmission from the moment you plug it in. This eliminates the need for a costly and time-consuming trip to the dealership for programming. For any professional mechanic or DIY enthusiast, this means a faster, more efficient repair that gets your truck back on the road with confidence.
A Technician’s Notebook: The Misdiagnosed Transmission
A customer brought in his ’08 Yukon XL, complaining of violent 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode). Another shop had quoted him over $3,000 for a transmission rebuild. He was understandably stressed. I hooked up my scan tool and saw a generic P0700 code, but also several solenoid communication errors. Instead of tearing into the transmission, I checked the TCM. In my 20+ years, I’ve learned that on these GM trucks, heat and vibration can degrade the TCM’s internal circuits over time, causing these exact ‘ghost’ issues. We swapped in a VIN-programmed 2007-2009 Yukon TCM, cleared the codes, and took it for a test drive. The shifting was perfect. A 30-minute fix saved him thousands and solved the problem for good. Never underestimate the importance of correct electronic diagnostics.
Is Your Yukon Exhibiting These Transmission Issues?
- ✔ Abrupt, harsh, or erratic gear shifts.
- ✔ The vehicle is stuck in a single gear, often called “limp mode.”
- ✔ Check Engine Light or Transmission Warning Light is illuminated on the dash.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, or other solenoid-related faults.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ A noticeable decrease in fuel economy due to inefficient shifting.
- ✔ Complete failure to upshift or downshift.
Your 30-Minute Path to a Smooth-Shifting Yukon
- ✔ Safety First: Before you begin, disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the system.
- ✔ Locate the Module: On most 2007-2009 Yukon models, the TCM is conveniently located in the engine bay, right next to the battery.
- ✔ Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. Then, unbolt the module from its mounting bracket.
- ✔ Install the New Module: Bolt the new, VIN-programmed TCM into place and securely reconnect the electrical harnesses. Ensure they click into place.
- ✔ Final Steps: Reconnect the negative battery terminal. While the module is plug-and-play, it’s best practice to use a basic OBD2 scan tool to clear any stored transmission codes. Start the vehicle and enjoy your restored ride!
Verified Vehicle Compatibility
This module is a direct replacement for part number 24243921 and other interchangeable numbers on a wide range of GM vehicles. While this page focuses on the 2007-2009 Yukon TCM, it also fits the following models. Please verify the location noted for your specific vehicle:
- GMC Yukon / Yukon XL 1500 (2007-2009): Transmission; (next to battery)
- Chevrolet Tahoe / Suburban 1500 (2007-2009): Transmission; (next to battery)
- Chevrolet Silverado 1500 / GMC Sierra 1500 (2007-2013): Transmission; (next to battery, check for new body style in ’07)
- Cadillac DTS (2006-2011): Transmission; (RH front engine compartment)
- Chevrolet Impala (2006-2011): Transmission; (lower air cleaner housing)
- Hummer H3 (2008-2010): Transmission; (RH rear engine compartment)
- Buick LaCrosse / Allure (2006-2009): Transmission; (lower air cleaner housing)
- Pontiac G6 (2006-2010): Transmission; (LH strut tower)
- And many more GM trucks, vans, and sedans from 2006-2014. Please use our vehicle selector tool to confirm an exact match.
Do I need to take this part to a dealer for programming?
No. This is the biggest benefit of our service. We program the module to your vehicle’s VIN before shipping, so it’s ready for immediate plug-and-play installation. This saves you hundreds of dollars and significant hassle.
What is a core charge? Do I need to send my old part back?
There is no core charge for this part. You can keep your old module, recycle it, or dispose of it without any obligation to return it to us.
What kind of warranty is included?
This transmission control module comes with a one-year warranty, covering any defects in materials or workmanship for your peace of mind.
Will this fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While a faulty TCM is a very common cause, this code can also be triggered by issues with solenoids or wiring. Replacing the TCM often resolves the P0700 and related codes, but proper diagnosis is always recommended.
Is installation difficult for a DIYer?
Not at all. For most vehicles like the Yukon, the TCM is easily accessible in the engine bay. With basic hand tools and our instructions, most people can complete the swap in under 30 minutes.