Restore Smooth Shifting to Your GMC Yukon XL 1500
If your 2007-2008 GMC Yukon XL 1500 is suffering from harsh shifting, getting stuck in gear, or throwing transmission-related error codes, a failing Transmission Control Module (TCM) is the most likely culprit. As a mechanic with over two decades of diagnostic experience, I’ve seen these T42 modules cause countless headaches for vehicle owners. This isn’t just a part; it’s the solution to get your truck’s powertrain operating reliably again. This module, part number 24230461, is the brain of your automatic transmission, controlling everything from shift points to torque converter clutch engagement to ensure peak performance and fuel efficiency.
A Technician’s Notebook: The Intermittent Gremlin
A customer brought in his ’07 Yukon XL, complaining of random, violent shifts and occasionally getting stuck in 3rd gear. The check engine light would come on and then disappear. We checked the fluid, scanned for codes (we found a history of P0752 – Shift Solenoid A Stuck On), and tested the solenoids, which all checked out fine. The issue was intermittent, making it a diagnostic nightmare. After confirming the wiring harness was secure, we pinpointed the T42 TCM. Heat soak was causing internal components to fail unpredictably. Installing a pre-programmed module like this one solved the problem instantly. The customer was back on the road in under an hour, without a costly dealership visit.
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 time to consider a replacement. Ignoring these symptoms can lead to more severe transmission damage.
- ✔ Abrupt, harsh, or delayed gear shifts.
- ✔ The vehicle enters “limp mode,” often stuck in a single gear (like 2nd or 3rd).
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700 (Transmission Control System Malfunction), P0750-P0758 (Solenoid Faults), or other transmission-related codes.
- ✔ Failure to upshift or downshift correctly.
- ✔ A noticeable decrease in fuel economy.
- ✔ Complete loss of communication with the module.
Your Plug-and-Play Installation Guide
One of the best features of this module is that it arrives programmed to your vehicle’s VIN, making installation a straightforward job for any DIY enthusiast. For your 2007-2008 Yukon XL 1500 TCM, the module is conveniently located in the engine bay, right next to the battery.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the TCM: Open the hood and find the TCM mounted next to the battery on the driver’s side.
- 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 TCM into place and securely reconnect the electrical harnesses. You should hear a click as they lock in.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the vehicle and ensure there are no warning lights. A short test drive will confirm that shifting has returned to normal. We recommend using a basic OBD2 scanner to clear any stored fault codes after installation.
Verified Compatibility for Your Vehicle
This T42 Transmission Control Module is a direct-fit replacement for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. While this page focuses on the 2007-2008 Yukon XL 1500 TCM, it also fits the following models. Always verify your part number (24230461) or contact us with your VIN.
- GMC: Yukon, Yukon XL 1500, Sierra 1500/2500, Savana, Envoy, Canyon
- Chevrolet: Tahoe, Suburban 1500, Silverado 1500/2500, Avalanche, Express, Impala, Cobalt, HHR, Colorado
- Cadillac: DTS
- Buick: LaCrosse, Lucerne, Rainier, Allure
- Pontiac: G6, Grand Prix
- And more: Hummer H3, Saab 9-7X, Saturn Vue, Ion, Aura
Frequently Asked Questions
What does ‘VIN Programmed’ mean for me?
It means we flash the module with your vehicle’s specific Vehicle Identification Number (VIN) and the latest GM software before shipping. This ensures it communicates perfectly with your vehicle’s other computers right out of the box, eliminating the need for an expensive trip to the dealership for programming.
Is this a difficult part to install myself?
Not at all. For the Yukon XL 1500, the TCM is easily accessible in the engine bay. With basic hand tools, the swap typically takes less than 30 minutes. Our step-by-step guide makes the process simple.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the main engine computer (ECM) to turn on the check engine light. While this module often resolves the underlying issue causing the P0700, you should scan for more specific P-codes (like solenoid or sensor faults) to confirm the TCM is the root cause.
Do I need to send my old part back?
No, there is no core charge for this part. You can keep your old module or recycle it locally, making the process hassle-free.
What kind of warranty is included?
This module is backed by our comprehensive one-year warranty, giving you confidence and peace of mind in your repair.