Is your Chevrolet Tahoe suffering from unpredictable, harsh shifting, or getting stuck in gear? These are classic signs of a failing Transmission Control Module (TCM), the electronic brain of your automatic transmission. This replacement T42 TCM, part number 24239926, is the definitive solution for restoring smooth, reliable performance to your 2007-2009 Tahoe and a wide range of other GM vehicles. Forget expensive dealership visits and complex procedures; this module arrives pre-programmed to your vehicle’s specific VIN, making it a true plug-and-play fix.
Solving the Root Cause of Your Transmission Woes
The TCM is responsible for every gear change, managing hydraulic pressure and interpreting data from sensors all over your vehicle. Over time, heat cycles and engine vibrations can degrade its internal circuits, leading to the frustrating problems you’re experiencing. A faulty TCM doesn’t just make for an unpleasant drive; it can cause poor fuel economy, premature transmission wear, and even leave you stranded in limp mode. By installing this quality-tested module, you’re not just replacing a part—you’re restoring the core logic that makes your transmission work as intended.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 Tahoe with an intermittent—and very annoying—problem. It would shift perfectly for days, then suddenly slam into gear at a stoplight or refuse to upshift on the highway. They had already replaced a shift solenoid with no luck. After scanning, we found a generic P0700 code but no specific solenoid faults. In my shop, I’ve learned that when electrical transmission gremlins appear without a clear mechanical cause, the TCM is the prime suspect. The internal logic was failing intermittently under load. We installed a VIN-programmed T42 module, and the problem was solved instantly. It’s a textbook example of how a failing 2007-2009 Tahoe TCM can mimic other issues, making a direct replacement the most efficient repair.
Is Your Tahoe Exhibiting These Transmission Problems?
If you’re nodding along to any of these symptoms, a failing TCM is the likely culprit. Look out for:
- ✔ Harsh, banging, or erratic gear shifts.
- ✔ The 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.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ Failure to upshift or downshift, leading to poor acceleration or high RPMs.
- ✔ A noticeable drop in fuel efficiency.
Your Straightforward 30-Minute Installation Guide
You don’t need to be a master mechanic to install this part. With basic hand tools, you can get your vehicle back to normal in under half an hour. For the 2007-2009 Chevy Tahoe, you’ll typically find the TCM located in the engine bay, right next to the battery.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electronic work. This prevents short circuits and helps reset the vehicle’s computer systems.
- Locate the Module: On your Tahoe, open the hood and find the TCM mounted next to the battery. It’s a small metal box with several large electrical connectors.
- Disconnect and Remove: Carefully unplug the wiring harnesses. They have locking tabs that may need to be pressed or lifted. Once disconnected, unbolt the old 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 and lock into position.
- Final Steps: Reconnect the negative battery terminal. Start the vehicle and take it for a test drive to confirm that shifting is smooth and responsive. While the battery disconnect clears most codes, using a basic OBD2 scan tool to clear any stored DTCs is good practice.
Verified Fitment Across a Range of GM Vehicles
While this is the perfect 2007-2009 Tahoe TCM, it is also designed to work with a vast array of GM cars, trucks, and SUVs equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. It is a direct replacement for part numbers 24252114, 24234503, 24239926, and others. Please verify your vehicle in the list below:
- Chevrolet: Tahoe (07-09), Silverado (07-13), Suburban (07-08), Avalanche (07-08), Express Van (06-14), Colorado (08-12), Impala (06-11), Cobalt (06-10), HHR (06-11), Monte Carlo (06-07), SSR (05-06)
- GMC: Yukon / Yukon XL (07-08), Sierra (07-13), Savana Van (06-14), Canyon (08-12), Envoy (06-09)
- Cadillac: DTS (06-11)
- Buick: LaCrosse (06-09), Lucerne (06-11), Allure (06-09), Rainier (06-07), Rendezvous (06-07)
- Pontiac: G6 (06-10), Grand Prix (06-08), G5 (07-10), Pursuit (06)
- Saturn: Vue (07-10), Aura (07-09), Ion (06-07)
- Hummer: H3 (08-10)
- Saab: 9-7X (06-09)
Frequently Asked Questions
Do I need to have this module programmed by a dealer?
No. This is the biggest benefit of our service. We program the module to your vehicle’s VIN before shipping it. It arrives ready for immediate installation, saving you time and the high cost of dealership programming.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault request from the TCM to the main engine computer. While it can be triggered by other issues, a faulty TCM is one of the most common root causes. Replacing a bad TCM will often resolve the P0700 code and any related specific codes (like for solenoids).
Is there a core charge for my old part?
No, there is no core charge. You can keep your old part or dispose of it without the hassle of sending it back to us.
What tools are required for installation?
Installation typically only requires basic hand tools, such as a socket set and ratchet to unbolt the module and disconnect the battery. No specialized equipment is needed.
How do I know this is the correct part for my vehicle?
This T42 module replaces a wide range of original part numbers, including 24239926. The best way to confirm is to check our detailed fitment list or match your existing part number. When you provide your VIN at checkout, we perform a final verification to ensure 100% compatibility.