Restore Flawless Shifting to Your GMC Yukon
If your 2007-2009 GMC Yukon is suffering from harsh shifting, getting stuck in gear, or throwing transmission codes, the culprit is often a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless GM trucks and SUVs sidelined by this exact issue. The T42 TCM is the electronic brain of your 4-speed automatic transmission (like the 4L60E, 4L65E, and 4L70E), and when it fails, it can cause a cascade of frustrating and potentially damaging problems. This isn’t just an inconvenience; it affects your vehicle’s reliability and safety.
We offer a dependable, long-term solution. This OEM-quality T42 TCM, part number 24239926, arrives at your door pre-programmed to your vehicle’s specific VIN. This crucial step eliminates the need for expensive dealership visits for programming, making it a true plug-and-play repair. By installing this module, you’re not just replacing a part; you’re restoring the precise, factory-intended communication between your engine and transmission for smoother gear changes, optimal fuel economy, and peace of mind.
Case Study: A Tricky Diagnosis
A customer brought in their ’08 Yukon XL with a complaint that stumped two other shops: intermittent, violent 1-2 shifts, but only after driving for 20+ minutes. There were no hard codes, just a pending P0700 (Transmission Control System Malfunction). We suspected the TCM was failing under heat. Instead of a costly diagnostic teardown, we suggested starting with this VIN-programmed module. After a simple 20-minute swap right there in the bay, the customer took it for a long test drive. The problem was gone. The heat soak was causing internal circuit failure in the old module—a classic T42 failure I’ve diagnosed hundreds of times. This part provided a definitive fix without the guesswork.
Is Your Yukon Exhibiting These Telltale Signs?
A faulty TCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement:
- âś” Unpredictable, harsh, or delayed gear shifts.
- âś” Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- âś” Check Engine Light or Transmission Warning Light is on.
- âś” Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750-P0758 (solenoid circuit faults), or other transmission-related codes.
- âś” Failure to upshift or downshift properly.
- âś” Noticeable decrease in fuel efficiency.
A Straightforward 30-Minute Installation
One of the best features of this part is its ease of installation. You don’t need to be a master mechanic to get your truck running right again. For most GMT900 trucks and SUVs like your Yukon, the TCM is located right next to the battery in the engine compartment.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning work. This prevents electrical shorts and helps reset the vehicle’s systems.
- Locate the TCM: On your 2007-2009 Yukon, it’s typically mounted in a bracket next to the battery. It’s a silver box with large electrical connectors.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. 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. Ensure they click into place.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s always good practice to use a basic scan tool to clear any stored DTCs from the vehicle’s memory.
Why Choose Our Programmed 2007-2009 Yukon TCM?
This isn’t just another replacement part. It’s a complete solution designed to save you time, money, and headaches. The VIN-programming ensures that the module works seamlessly with your Yukon’s specific configuration and has the latest GM software updates for optimal performance. Backed by our one-year warranty, you can be confident you’re making a lasting repair.
Verified Fitment for Your General Motors Vehicle
This T42 TCM is a direct replacement for part number 24239926 and interchanges with numerous other part numbers. While this page focuses on the 2007-2009 Yukon TCM, it is also compatible with a wide range of GM vehicles, including:
GMC: Yukon (2007-2009), Yukon XL 1500 (2007-2008), Sierra 1500/2500 (2007-2013), Savana Vans (2006-2014), Envoy (2006-2009), Canyon (2008-2012)
Chevrolet: Tahoe (2007-2009), Silverado 1500/2500 (2007-2013), Suburban 1500 (2007-2008), Express Vans (2006-2014), Impala (2006-2011), HHR (2006-2011), Cobalt (2006-2010), Trailblazer (2006-2009), Colorado (2008-2012)
Cadillac: DTS (2006-2011)
Buick: LaCrosse (2006-2009), Lucerne (2006-2011), Rainier (2006-2007)
And many more Pontiac, Saturn, Hummer, and Saab models. Please verify your specific model and year in the fitment list below.
Do I need to take this part to a dealer for programming?
Do I need to take this part to a dealer for programming?
No. This is the primary benefit of our service. We program the module to your vehicle’s VIN before shipping it. This makes the installation plug-and-play, saving you the time and expense of a dealership visit.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the main computer (PCM) to turn on the check engine light. While the P0700 itself is generic, it’s almost always triggered by a more specific fault within the transmission system. A failing TCM is a very common cause of this code, so replacing it often resolves the issue, especially if accompanied by solenoid or shifting performance codes.
Where is the TCM located on my 2008 GMC Yukon?
On the 2007-2009 GMC Yukon, Chevrolet Tahoe, and similar GM trucks, the T42 TCM is typically located in the engine bay, mounted to a bracket right next to the battery. Its location makes it very easy to access for replacement.
Is this compatible with my 4L60E transmission?
Yes. This T42 module is the correct controller for GM vehicles equipped with 4-speed automatic transmissions from this era, including the 4L60E, 4L65E, 4L70E, and 4L80E.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old part, which simplifies the process for you. You don’t have to worry about packaging and shipping the old module back to us.