If your 2006 GMC Envoy XL is suffering from erratic shifting, getting stuck in gear, or has thrown a Check Engine Light, a failing Transmission Control Module (TCM) is the most likely culprit. As a technician with over two decades of experience, I’ve seen these T42 modules cause countless headaches for drivers. This isn’t just an annoyance; it’s a reliability issue that can leave you stranded. This direct-replacement TCM, part number 24239926, is the definitive solution to restore the crisp, predictable performance your GM vehicle was built for.
The real value here is our pre-programming service. We flash this module with your vehicle’s specific VIN and the latest GM software before it ships. This means you can skip the expensive trip to the dealership for programming. It arrives at your door ready for a true plug-and-play installation, making it a perfect job for a DIYer or a time-saving solution for a professional shop. This module directly communicates with the transmission’s solenoids and sensors to manage shift points, torque converter clutch engagement, and line pressure, fixing the root cause of many common transmission problems.
Case Study: The ‘Limp Mode’ Envoy
A customer brought in a 2006 Envoy XL, complaining it was stuck in what felt like third gear (a classic ‘limp mode’ symptom) and the transmission warning light was on. A quick scan showed a P0700 (Transmission Control System Malfunction) and a few solenoid circuit codes. Instead of jumping to a costly transmission rebuild, we checked the basics. The fluid was fine, and the wiring to the TCM looked good. Based on my experience with hundreds of these GM platforms, the T42 TCM itself was the prime suspect. We installed one of our VIN-programmed modules, cleared the codes, and took it for a test drive. The shifting was immediately smooth and responsive. The customer saved thousands compared to a transmission replacement and was back on the road in under an hour.
Is Your Envoy XL Showing These Telltale Signs?
A faulty TCM can manifest in several ways. If you’re noticing any of the following, it’s time to consider a replacement 2006 Envoy XL Transmission Control Module:
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ The vehicle is stuck in a single gear (limp mode) and won’t shift up or down.
- ✔ An illuminated Check Engine Light or transmission warning light.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔ A noticeable drop in fuel economy or a transmission that seems to be overheating.
- ✔ Complete loss of communication with the transmission module.
Your Quick Guide to a Smooth Installation
Replacing the TCM is a straightforward process that you can complete with basic hand tools in your own garage. For the 2006 Envoy XL, the module is typically found in the engine compartment on the driver’s side.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work. This prevents short circuits and helps reset the vehicle’s electronic systems.
- Locate the Module: On your Envoy XL, the TCM is usually mounted in the left-hand (driver’s side) of the engine compartment. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unclip the wiring harness connectors. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the wiring harnesses. Ensure the clips click into place.
- Final Steps: Reconnect the battery terminal. While our programming handles the critical setup, it’s good practice to use a basic OBD2 scan tool to clear any lingering fault codes from the vehicle’s memory. Start the engine and enjoy your smooth-shifting transmission!
Verified Fitment for Your General Motors Vehicle
While this is the correct 2006 Envoy XL Transmission Control Module, this T42 unit is also compatible with a wide range of other GM cars, trucks, and SUVs equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. It interchanges with part numbers 24252114, 24234503, 24230461, 24234274, 24239926, and more. Please verify your vehicle in the fitment list below or contact our expert support team to ensure perfect compatibility.
Do I need to take this part to a dealer for programming?
Do I need to take this part to a dealer for programming?
No. We pre-program the module to your vehicle’s specific VIN before shipping. This makes the installation plug-and-play, saving you time and the high cost of dealership programming.
What is a T42 TCM?
T42 is the hardware designation for this generation of General Motors Transmission Control Module. It was used across a vast number of vehicles from roughly 2006 to 2014 with 4-speed automatic transmissions.
Will this fix a P0700 code?
A P0700 is a generic code indicating the TCM has detected a fault. In many cases, a failing TCM is the root cause, and replacing it will resolve the P0700 and any related specific codes (like for shift solenoids). However, you should always ensure the transmission wiring and fluid levels are correct as part of your diagnosis.
Is there a core charge for my old part?
No, there is no core charge required for this part. You can keep your old module without any hassle or need to return it.
What kind of warranty is included?
This module is backed by our one-year, hassle-free warranty, giving you peace of mind and confidence in your repair.