Is Your 2007-2009 GMC Yukon Shifting Erratically?
A faulty Transmission Control Module (TCM) can turn your reliable GMC Yukon into a frustrating and unpredictable ride. If you’re experiencing harsh shifts, delayed gear engagement, a check engine light with transmission codes, or the dreaded “limp mode,” the problem is likely your T42 TCM. This electronic brain of your transmission is responsible for every gear change, and when it fails, performance suffers dramatically. Don’t let a failing module sideline your vehicle. This direct-fit replacement GM T42 Transmission Control Module, part number 24234274, is the definitive solution to restore your transmission’s smooth, factory-new operation.
The Critical Role of a Programmed 2007-2009 Yukon Transmission Module
The TCM is more than just a simple controller; it’s a sophisticated computer that constantly analyzes data from sensors throughout your vehicle. It monitors engine RPM, vehicle speed, throttle position, and more to determine the precise moment to shift gears for optimal performance and fuel economy. When it begins to fail, the signals it sends to the transmission’s hydraulic solenoids become erratic, leading to the symptoms you’re experiencing. Our module comes pre-programmed to your Yukon’s specific Vehicle Identification Number (VIN), ensuring it has the latest GM software and is perfectly calibrated to your truck’s unique specifications right out of the box. This eliminates the need for expensive dealership programming and guarantees a seamless plug-and-play installation.
From the Diagnostic Bay
We had a 2008 Yukon come into the shop with classic transmission failure symptoms: banging into gear and getting stuck in 3rd. The owner had already spent a small fortune at another shop replacing multiple shift solenoids and even the valve body, but the problem persisted. After a quick scan, we saw communication error codes pointing away from the internal components. We located the T42 module next to the battery, and it showed subtle signs of heat stress. We installed one of our VIN-programmed modules, cleared the codes, and the truck shifted perfectly on the first test drive. The customer was thrilled to have a final fix, proving that diagnosing the external ‘brain’ first can save hundreds, if not thousands, in unnecessary internal transmission work.
Common Symptoms of a Failing T42 TCM
- ✔ Erratic and Harsh Shifting: Your Yukon may slam into gear, hesitate, or shift at the wrong times.
- ✔ Stuck in Gear / Limp Mode: The transmission may default to a single gear (often 2nd or 3rd) to prevent further damage.
- ✔ Check Engine Light: You’ll often see transmission-specific Diagnostic Trouble Codes (DTCs) like P0700, P0750, or other solenoid circuit codes.
- ✔ Delayed Engagement: A noticeable lag when shifting from Park into Drive or Reverse.
- ✔ Poor Fuel Economy: Inefficient shifting forces the engine to work harder, consuming more fuel.
- ✔ No Communication: A scan tool may be unable to communicate with the transmission module, indicating a complete failure.
Installation is Simpler Than You Think
Replacing the TCM is a straightforward job that most DIY mechanics can complete in under 30 minutes. The module is located in the engine bay, typically next to the battery, on the LH strut tower, or near the air cleaner box depending on your specific GM model. Simply disconnect the negative battery terminal, unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. Reconnect everything, and you’re ready to go. Because our modules are pre-programmed, there are no complex relearn procedures required. Just clear any old codes with a basic scan tool, and enjoy your smooth-shifting ride.
This module is a direct replacement for a wide range of service numbers, including: 24252114, 24234503, 24230461, 24235340, 24235754, 24238856, 24239224, 24239926, 24240400, 24241806, 24243901, 24243921, 24255280, 24256960, and more. It is designed for vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E.
Frequently Asked Questions
Will I need to take my vehicle to the dealer for programming?
No. This Transmission Control Module comes fully pre-programmed to your vehicle’s VIN. This is a complete plug-and-play solution, saving you the time and expense of a dealership visit.
What is a T42 TCM?
The T42 is the specific hardware platform name for the Transmission Control Module used in a wide range of General Motors vehicles from approximately 2006 to 2014 with 4-speed automatic transmissions. It’s the computer responsible for controlling all transmission functions.
Where is the TCM located on my 2007-2009 Yukon?
On most 2007-2009 GMC Yukon, Tahoe, Silverado, and Sierra models, the T42 TCM is conveniently located in the engine compartment, mounted right next to the battery. This makes access and replacement very straightforward.
Is this a reliable, quality part?
Absolutely. This module is built to meet or exceed original equipment standards for performance and durability. It is rigorously tested to ensure reliable operation and is backed by our one-year warranty for your peace of mind.
What happens if I don’t replace a failing TCM?
Continuing to drive with a faulty TCM can lead to more severe and expensive damage. Poor shifting can cause excessive wear on clutches, bands, and other internal transmission components, potentially leading to a complete transmission failure that requires a full rebuild or replacement.