If your GMC Yukon is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, you’re not just dealing with an annoyance—you’re facing a critical failure that can leave you stranded. As a technician with over two decades of experience, I’ve seen countless drivers frustrated by these exact issues. The culprit is often a failing Transmission Control Module (TCM), the electronic brain of your automatic transmission. This VIN-programmed T42 TCM is the reliable, direct-fit solution designed to restore your vehicle’s performance and your peace of mind.
This isn’t just a replacement part; it’s a permanent fix. We pre-program each module to your vehicle’s specific VIN, ensuring it arrives ready for a plug-and-play installation. This eliminates the need for expensive dealership visits for programming, saving you both time and money. Once installed, this module correctly manages shift points, torque converter lockup, and line pressure, bringing back the smooth, predictable operation you expect from your Yukon. It’s built to meet or exceed original equipment standards, providing a dependable solution for the 4L60E, 4L65E, and 4L70E transmissions commonly found in these SUVs.
From the Diagnostic Bay: The Case of the Hesitant Yukon
A customer brought in their ’08 Yukon, complaining of intermittent, harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode) after driving for 20 minutes. There were no consistent trouble codes, just a general P0700 (Transmission Control System Malfunction) that would pop up now and then. We checked the fluid, wiring, and solenoids—all seemed fine. After monitoring live data, we noticed the TCM was intermittently dropping communication. This is a classic sign of internal electronic failure. We swapped in one of our pre-programmed T42 modules, and the problem was solved instantly. The customer was back on the road in under an hour, without the hefty bill for diagnostic guesswork and dealer programming.
Is Your Yukon Exhibiting These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission breakdown. Often, the symptoms start small and get progressively worse. If you notice any of the following, it’s a strong indicator that your 2007-2009 Yukon TCM may be the root cause.
- ✔ Harsh, delayed, or unpredictable gear shifts.
- ✔ Vehicle entering ‘limp mode,’ refusing to shift out of a single gear.
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) stored, such as P0700, P0750, or other solenoid-related faults.
- ✔ A noticeable decrease in fuel economy due to inefficient shifting.
- ✔ Complete loss of communication with the transmission module.
A Straightforward 30-Minute Installation
You don’t need to be a professional mechanic to install this part. The process is simple and can be completed with basic hand tools right in your driveway. For the 2007-2009 GMC Yukon, the TCM is conveniently located next to the battery in the engine compartment.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the vehicle’s computer systems.
- Locate the Module: Open the hood and find the TCM mounted next to the battery. It will have several large electrical connectors attached.
- Disconnect and Remove: Carefully unclip the wiring harness connectors. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely reconnect the wiring harnesses, ensuring they click into place.
- Final Steps: Reconnect the negative battery terminal. While the module is plug-and-play, it’s good practice to use a basic OBD-II scan tool to clear any old fault codes from the system’s memory.
Verified Vehicle Compatibility List
This T42 Transmission Control Module, part number 24239224, is a direct replacement for a wide range of General Motors vehicles. While this page is focused on the 2007-2009 Yukon TCM, it also fits the models listed below. Please verify your vehicle and part number for a guaranteed fit.
- GMC Yukon / Yukon XL 1500 (2007-2009)
- Chevrolet Tahoe / Suburban 1500 (2007-2008)
- Chevrolet Silverado 1500 (2007-2013)
- GMC Sierra 1500 (2007-2013)
- Chevrolet Avalanche 1500 (2007-2008)
- Cadillac DTS (2006-2011)
- Buick Lucerne (2006-2011)
- Chevrolet Impala (2006-2011)
- Hummer H3 (2008-2010)
- And many more GM models from 2006-2014.
Frequently Asked Questions
Do I need to take this part to a dealership for programming?
No. We program the module to your vehicle’s VIN before shipping. It arrives ready to install, with no additional programming or setup required.
Is this a difficult part to install for a DIYer?
Not at all. For the GMC Yukon, the TCM is easily accessible in the engine bay next to the battery. With basic tools, most people can complete the replacement in under 30 minutes.
What is a core charge? Do I need to send my old part back?
There is no core charge for this module. You can keep your old part, so there’s no hassle with return shipping or waiting for a refund.
What kind of warranty is included?
This module is backed by our comprehensive one-year warranty, covering any defects in materials or workmanship for your complete confidence.