If you’re dealing with the frustration of a GMC Yukon that shifts erratically, gets stuck in gear, or has a lit-up check engine light, you’re likely facing a faulty Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen how a failing TCM can sideline a perfectly good truck. This isn’t just an annoyance; it’s a critical component failure that affects your vehicle’s drivability, fuel economy, and safety. This T42 series TCM, part number 24255280, is the reliable, pre-programmed solution to get your Yukon back to performing how it should.
The TCM is the brain of your automatic transmission. It takes data from various sensors around the vehicle to decide the perfect moment to shift gears, engage the torque converter, and monitor transmission health. When it starts to fail—often due to heat cycles and electronic wear—the symptoms can range from subtle hesitations to a complete refusal to shift. Our module solves this by arriving at your door programmed to your specific Vehicle Identification Number (VIN), eliminating the need for an expensive trip to the dealership for programming. It’s a true plug-and-play fix.
A Technician’s Notebook: The Intermittent Limp Mode Case
I remember a 2008 Yukon that came into my shop with a baffling problem. The owner said it would randomly go into ‘limp mode’ (stuck in 3rd gear) but only after driving for 30-40 minutes on a hot day. We’d scan it, find a generic P0700 transmission fault code, clear it, and the truck would drive fine. The issue was heat-soaking the TCM. The internal circuits were failing once they reached operating temperature, causing a communication breakdown. We replaced it with a pre-programmed T42 TCM, and the problem never returned. This is a classic failure pattern for these modules.
Is Your Yukon Showing These Transmission Warning Signs?
A failing TCM will give you clear signals. If you’re experiencing any of the following, it’s time to consider a replacement. Ignoring these can lead to more severe transmission damage.
- ✔ Harsh, jerky, or delayed gear shifts.
- ✔ Vehicle is stuck in one gear (often called “limp mode”).
- ✔ Check Engine Light or Transmission Warning Light is on with codes like P0700, P0750, or other solenoid-related DTCs.
- ✔ Inability to upshift or downshift properly.
- ✔ A noticeable drop in fuel efficiency.
- ✔ The transmission seems to be slipping between gears.
- ✔ Complete loss of communication with the transmission module.
A Straightforward Guide to Installation
Replacing the TCM on your 2007-2009 Yukon TCM is a job most DIYers can handle in their own driveway in under an hour. The module is typically located in the engine bay for easy access.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On most GMT900 trucks like the Yukon and Tahoe, you’ll find the TCM mounted next to the battery in the engine compartment.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place. Reconnect the electrical harnesses, ensuring they click securely into position.
- Final Steps: Reconnect the negative battery terminal. While the module is plug-and-play, it’s good practice to use a basic OBD2 scan tool to clear any stored fault codes from the ECU. Start the vehicle and test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This module is a direct replacement for part number 24255280 and other interchangeable numbers. It is designed for a wide range of GM vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. Please verify your vehicle from the list below:
- GMC Yukon / Yukon XL 1500 (2007-2009): Located next to the battery.
- Chevrolet Tahoe / Suburban 1500 (2007-2009): Located next to the battery.
- Chevrolet Silverado 1500 / GMC Sierra 1500 (2007-2013): Located next to the battery (for non-hybrid models).
- Chevrolet Avalanche 1500 (2007-2008): Located next to the battery.
- Cadillac DTS (2006-2011): Located in the RH front engine compartment.
- Chevrolet Impala (2006-2011): Located under the lower air cleaner housing.
- Hummer H3 (2008-2010): Located in the RH rear engine compartment.
- Chevrolet Colorado / GMC Canyon (2008-2012): Located in the RH rear engine compartment.
- …and many more GM models from 2006-2014. Please check the full fitment list for confirmation.
Frequently Asked Questions
Do I need to program this module?
No. We pre-program the module to your vehicle’s VIN before shipping. It arrives ready for immediate installation, saving you a trip to the dealer.
What tools are needed for installation?
You’ll typically only need basic hand tools, such as a socket set to disconnect the battery and unbolt the module. No special diagnostic equipment is required.
Is there a core charge for my old part?
No, there is no core charge. You can keep or dispose of your old module without the hassle of sending it back.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault request from the TCM to the ECM to turn on the check engine light. While a faulty TCM is a common cause, this code indicates a more specific code is stored in the TCM itself. Replacing a bad TCM will resolve the underlying issue causing the P0700.
What is the warranty on this part?
This Transmission Control Module comes with a one-year warranty, giving you peace of mind and confidence in your repair.