Restore Peak Transmission Performance in Your 2006-2009 GMC Envoy
If your GMC Envoy is suffering from erratic shifting, getting stuck in gear, or throwing transmission-related trouble codes, you’re not just dealing with an annoyance—you’re facing a potential reliability issue. As a technician with over two decades of experience, I’ve seen firsthand how a failing Transmission Control Module (TCM) can sideline an otherwise perfectly good vehicle. This OEM-quality T42 TCM, part number 24239224, is the definitive solution for your 2006-2009 Envoy TCM problems. It arrives expertly programmed to your vehicle’s specific VIN, eliminating the need for expensive dealership visits and ensuring a seamless, plug-and-play installation.
From the Diagnostic Bay: The Misleading Solenoid Code
A customer brought in a 2008 Trailblazer (which shares the same platform as the Envoy) with a classic complaint: harsh 1-2 shifts and a P0752 code for a stuck-on shift solenoid. The previous shop had already replaced the solenoid inside the transmission pan, but the problem persisted. After confirming the solenoid’s wiring was intact, my experience pointed directly to the brain—the TCM. These T42 modules are known to fail internally, causing them to send incorrect commands or fail to read sensor data properly. We installed a VIN-programmed module, and the shifting smoothed out instantly. The code never returned. This case highlights why replacing the 2006-2009 Envoy TCM is often the correct fix, saving you from unnecessary and costly internal transmission work.
Is Your Envoy’s Transmission Acting Up? Common Symptoms
A faulty TCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement:
- ✔ Harsh, slamming, or delayed gear shifts.
- ✔ The vehicle is stuck in “limp mode,” often only using 2nd or 3rd gear.
- ✔ An illuminated Check Engine Light or Transmission Warning Light.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, P0751, or other solenoid-related faults.
- ✔ Failure to upshift or downshift, leading to poor acceleration and fuel economy.
- ✔ Complete loss of communication with the transmission module.
Get Your Envoy Back on the Road: A Simple Installation Guide
One of the best features of this part is its straightforward installation, which a DIYer with basic tools can complete in under 30 minutes. Your 2006-2009 Envoy TCM is conveniently located in the engine compartment.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the system.
- Locate the Module: On the GMC Envoy, the TCM is typically found in the left-hand (driver’s side) of the engine compartment.
- Disconnect and Remove: Carefully unclip the electrical connectors. Be gentle with the locking tabs. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new VIN-programmed TCM into place and securely reconnect the electrical harnesses. You should hear a click as they lock.
- Reconnect and Verify: Reconnect the battery terminal. Start the vehicle and allow it to idle for a moment. Use a basic OBD2 scanner to clear any stored fault codes and take it for a test drive to confirm smooth operation.
Confirmed Vehicle Compatibility List
This module is a direct replacement for part number 24239224 and is interchangeable with several other service numbers. It fits a wide range of General Motors vehicles beyond the Envoy. Please verify your model and year below:
- GMC Envoy: 2006-2009
- Chevrolet Trailblazer: 2006-2009 (8 cylinder)
- Chevrolet Silverado & GMC Sierra 1500/2500: 2007-2013 (See specific options)
- Chevrolet Tahoe & GMC Yukon: 2007-2009
- Cadillac DTS: 2006-2011
- Hummer H3: 2008-2010
- Chevrolet Impala: 2006-2011
- Pontiac G6: 2006-2010
- …and many other GM cars, trucks, and SUVs. Please check the full fitment list for your specific vehicle.
Frequently Asked Questions
Do I need to take this part to a dealer for programming?
No. This module is delivered pre-programmed to your vehicle’s VIN. It is ready for installation right out of the box, saving you time and money on dealership programming fees.
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. In many cases, a failing TCM is the root cause. Replacing the module with this part is a very common and effective fix for a P0700 accompanied by other transmission-specific codes.
Is this a difficult part to install myself?
Not at all. For most models, including the GMC Envoy, the TCM is located in an easily accessible spot in the engine bay. With basic hand tools, most people can swap the module in under 30 minutes.
What is the warranty on this TCM?
This Transmission Control Module comes with a one-year warranty, giving you confidence and peace of mind in your repair.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old part without the hassle of returning it.