If you’re dealing with a GMC Yukon that shifts hard, gets stuck in gear, or throws transmission codes, you’ve come to the right place. As a technician with over two decades of experience, I’ve seen firsthand how a failing Transmission Control Module (TCM) can bring a perfectly good truck to its knees. This isn’t just an inconvenience; it’s a critical failure that compromises drivability. This T42 TCM, part number 24235754, is the definitive, hassle-free solution for your 2007-2009 GMC Yukon and a wide range of other GM vehicles.
The TCM is the electronic brain of your automatic transmission. It processes data from various sensors to command precise gear shifts, manage torque converter lockup for fuel efficiency, and monitor the overall health of the system. When it fails, the symptoms can be unpredictable and frustrating. Our module eliminates the guesswork by arriving pre-programmed to your vehicle’s specific VIN, ensuring it works perfectly right out of the box—no expensive trip to the dealership for programming is required.
A Technician’s Notebook: The Phantom Solenoid Problem
I had a 2008 Yukon in the bay last month with a classic complaint: intermittent ‘limp mode’ and a check engine light for a shift solenoid code (P0752 – Shift Solenoid ‘A’ Stuck On). The owner had already replaced the solenoid twice, but the problem kept returning. This is a textbook case I’ve diagnosed hundreds of times. The issue wasn’t the solenoid; it was the TCM’s internal driver circuit for that solenoid failing under heat. We installed one of our VIN-programmed T42 modules, and the problem was solved instantly. The truck has been shifting flawlessly ever since. Don’t chase parts—address the root cause.
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 highly likely your module is the culprit:
- âś” Harsh, slamming shifts or delayed gear engagement.
- âś” Vehicle is stuck in a single gear (often 2nd or 3rd), known as ‘limp mode’.
- âś” Check Engine Light or Transmission Warning Light is on.
- âś” Diagnostic Trouble Codes (DTCs) are present, especially a general code like P0700 or specific solenoid codes (P0750-P0774 series).
- âś” Inability to upshift or downshift, leading to poor acceleration and terrible fuel economy.
- âś” The transmission feels like it’s slipping between gears.
Your 30-Minute Path to a Smooth-Shifting Yukon
Replacing the TCM is a straightforward job that most DIYers can complete in their driveway. For the 2007-2009 Yukon, it’s typically located right next to the battery.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and help reset the system.
- Locate the Module: Find the TCM in the engine bay. On most GMT900 trucks like the Yukon, it’s mounted on a bracket next to the battery.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Reconnect the electrical connectors, ensuring they click securely into place.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the vehicle and check for any warning lights. A short drive will allow the system to confirm proper operation. For best results, use a basic scan tool to clear any stored historical codes.
Verified Fitment Across the GM Family
This T42 TCM is a direct replacement for part number 24235754 and is interchangeable with many other service numbers. It fits a vast array of GM vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. Please verify your vehicle in the list below:
This part will fit these makes and models with these options
YUKON 07-09 Transmission; (next to battery)
AVALANCHE 1500 07-08 Transmission; (next to battery)
CANYON 08-12 Transmission; (RH rear engine compartment)
COLORADO 08-12 Transmission; (RH rear engine compartment)
ENVOY 06-09 Transmission; (LH engine compartment)
EXPRESS 1500/2500/3500 VAN 06-14 Transmission; (RH engine compartment)
HUMMER H3 08-10 Transmission; (RH rear engine compartment)
SAAB 9-7X 06-09 Transmission; (LH engine compartment)
SAVANA 1500/2500/3500 VAN 06-14 Transmission; (RH engine compartment)
SIERRA 1500 PICKUP 07-13 Transmission; (next to battery)
SIERRA 2500 PICKUP 07 Transmission; new style (smooth door skin), 6.0L, (next to battery)
SILVERADO 1500 PICKUP 07-13 Transmission; (next to battery)
SILVERADO 2500 PICKUP 07 Transmission; new style (smooth door skin), 6.0L, (next to battery)
SUBURBAN 1500 07-08 Transmission; (next to battery)
TAHOE 07-09 Transmission; (next to battery)
TRAILBLAZER 06-09 Transmission; (LH engine compartment)
…and many other Buick, Cadillac, Chevrolet, Pontiac, and Saturn models.
Frequently Asked Questions
Frequently Asked Questions
What exactly does a Transmission Control Module (TCM) do?
The TCM acts as the central computer for your automatic transmission. It takes information from engine and vehicle speed sensors to control when the transmission shifts gears, ensuring smooth operation and optimal fuel economy.
Is this part really plug-and-play?
Yes. We program the module to your vehicle’s VIN before shipping. This means it’s ready for installation right out of the box, with no need for additional programming from a dealer or specialized shop.
Do I need to return my old TCM? Is there a core charge?
No. We do not require you to return your old part, and there is absolutely no core charge, saving you time and hassle.
Will this fix my P0700 transmission code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While this module often resolves the underlying issue causing the P0700 (like a failed internal circuit), you should scan for more specific codes (e.g., P07xx) to confirm the diagnosis. In many cases, replacing a faulty TCM is the correct fix.
Where is the TCM located on my 2008 GMC Yukon?
On the 2007-2009 GMC Yukon, as well as similar models like the Tahoe and Silverado, the TCM is typically mounted on a bracket in the engine compartment, right next to the battery. It’s easily accessible.