Restore Your Yukon’s Drivability and Performance
If your 2007, 2008, or 2009 GMC Yukon is suffering from erratic shifting, getting stuck in gear, or throwing transmission-related codes, the culprit is often a failing Transmission Control Module (TCM). As a technician with over two decades of experience under the hood, I’ve seen countless drivers worry about a costly transmission rebuild when the real problem was this critical electronic component. This T42 TCM, part number 24243921, is the reliable, cost-effective solution to get your SUV’s automatic transmission operating like new again.
The TCM is the brain of your transmission, responsible for managing shift points, torque converter clutch engagement, and fluid pressure. When it fails, communication between the engine and transmission breaks down, leading to the frustrating and sometimes dangerous symptoms you’re experiencing. Our module solves this by being pre-programmed to your vehicle’s specific VIN, ensuring it works perfectly right out of the box without a mandatory trip to the dealership for expensive programming. This is the definitive fix for your 2007-2009 Yukon Transmission Control Module issues.
Case Study: The $3000 Quote That Became a $300 Fix
A customer brought in their 2008 Yukon last month, completely frustrated. The vehicle was stuck in ‘limp mode’ (3rd gear only), and another shop had quoted them nearly $3,000 for a transmission rebuild. The check engine light was on, and they were ready to give up on the truck. I hooked up my scan tool and found a classic P0700 code (Transmission Control System Malfunction) and several solenoid communication errors. Instead of tearing down the transmission, I started with the basics. After checking the wiring harness, I suspected the TCM. We installed one of our VIN-programmed modules, cleared the codes, and took it for a test drive. The shifting was perfect, and all codes were gone. We saved that customer thousands of dollars and a massive headache with the right diagnosis and the right part.
Is Your Yukon’s Transmission Sending Out an S.O.S.?
A failing TCM will give you clear warning signs. If you’re noticing any of the following, it’s time to inspect your module. Ignoring these symptoms can lead to more significant and expensive transmission damage down the road.
- ✔ Harsh, delayed, or unpredictable gear shifts.
- ✔ The vehicle is stuck in a single gear (limp mode).
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults are present.
- ✔ Poor fuel economy and a feeling of lost power.
- ✔ Complete loss of communication with the transmission.
Get Your Yukon Shifting Smoothly: A 30-Minute Install Guide
Replacing the 2007-2009 Yukon Transmission Control Module is a straightforward job that most DIYers can handle in their own driveway. No specialized tools are needed.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system’s memory.
- Locate the Module: On most 2007-2009 Yukons, the TCM is located in the engine bay, typically next to the battery. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical wiring harnesses. They have locking tabs that need to be pressed. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place. Securely plug in the wiring harnesses, ensuring they click to confirm a solid connection.
- Final Steps: Reconnect the negative battery terminal. Start the vehicle and allow it to idle for a few minutes. If you have a scan tool, use it to clear any stored DTCs from the computer’s memory. Test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of General Motors vehicles equipped with the T42 TCM and 4-speed automatic transmissions (like the 4L60E, 4L65E, 4L70E). While this page focuses on the 2007-2009 Yukon Transmission Control Module, it also fits the following models. Please verify your specific model and options.
Partial Fitment List: GMC Yukon (07-09), Sierra (07-13), Savana (06-14), Envoy (06-09); Chevrolet Tahoe (07-09), Silverado (07-13), Suburban (07-08), Express (06-14), Colorado (08-12), Impala (06-11); Cadillac DTS (06-11); Hummer H3 (08-10) and many more. This part interchanges with numbers 24252114, 24234503, 24243901, and others.
Frequently Asked Questions
What exactly is VIN programming and why is it important?
VIN programming involves loading your vehicle’s unique 17-digit Vehicle Identification Number into the module. This ensures the TCM has the correct software and calibrations for your Yukon’s specific engine, transmission, and options. It makes the part truly plug-and-play and avoids the need for expensive dealer tools.
Do I need to send my old TCM back (core charge)?
No, there is no core charge for this part. You can keep your old module or recycle it locally, making the process hassle-free.
Is this a difficult part for a DIYer to install?
Not at all. With basic hand tools and our step-by-step guide, most people can complete the installation in under 30 minutes. The most common location next to the battery is easily accessible.
Will this fix a P0700 check engine light code?
Yes, if the root cause of the P0700 code is a faulty TCM, this part is designed to resolve it. P0700 is a general code indicating a fault in the transmission control system, and a failing module is a very common trigger for it.
What is the warranty on this module?
This Transmission Control Module comes with a one-year warranty, giving you peace of mind and confidence in your repair.