Restore Your GM’s Shifting Performance
If your 2006 GMC Envoy XL is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, you’re not just dealing with an annoyance—you’re facing a potential breakdown. As a technician with over two decades of experience, I’ve seen countless GM vehicles, from hardworking Silverado trucks to family-hauling Tahoes, sidelined by a faulty Transmission Control Module (TCM). The T42 TCM is the electronic brain of your 4-speed automatic transmission (like the 4L60E, 4L65E, and 4L70E), and when it fails, your vehicle’s reliability is compromised. This replacement T42 TCM, part number 24230461, is the definitive solution.
We take the guesswork and dealership hassle out of the repair. Each module is expertly programmed to your vehicle’s specific VIN before shipping. This means it arrives at your door ready for a true plug-and-play installation, loaded with the latest GM software updates for your exact vehicle. You get restored performance, smoother shifting, and better fuel economy without the high cost and long wait times of a dealership visit.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 Sierra 1500 with classic symptoms: harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode), with a P0700 code. They had already replaced two shift solenoids with no luck. In my shop, I’ve learned that while solenoids can fail, the root cause is often the TCM itself. Heat cycles and vibrations in the engine bay cause microscopic cracks in the TCM’s circuit board over time, leading to intermittent commands. We installed one of our VIN-programmed T42 modules. The installation took 20 minutes, and after clearing the codes, the truck shifted like it just rolled off the factory floor. The customer saved hundreds by avoiding unnecessary parts and a trip to the dealer.
Is Your GM Vehicle Showing These Telltale Signs?
- ✔ Harsh, banging, or delayed gear shifts.
- ✔ Vehicle is stuck in ‘limp mode’ and will not shift out of 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔ Complete loss of gear engagement or inability to upshift/downshift.
- ✔ Poor fuel mileage and a feeling of sluggish performance.
A Straightforward Guide to Your 2006 Envoy XL TCM Installation
Replacing the TCM is a job most DIYers can handle in their own driveway. No specialized tools are required.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the Module: On most GM trucks and SUVs like the Envoy XL, the TCM is found in the engine compartment, often on the driver’s side near the strut tower or under the air cleaner box. Refer to the fitment list for common locations.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that need to be released. 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.
- Final Steps: Reconnect the battery terminal. Start the vehicle and use a basic OBD2 scan tool to clear any stored transmission codes. Your vehicle is now ready for a test drive.
Verified Fitment for Your General Motors Vehicle
This module is a direct replacement for a wide range of GM vehicles. It is interchangeable with part numbers 24252114, 24234503, 24230461, and more. Please verify your model and location below:
- GMC Envoy / Envoy XL / Trailblazer (2006-2009): Located in the LH engine compartment.
- Chevrolet Silverado / GMC Sierra 1500, 2500 (2007-2013): Typically found next to the battery.
- Chevrolet Tahoe / Suburban / GMC Yukon (2007-2009): Located next to the battery.
- Chevrolet Express / GMC Savana Vans (2006-2014): Found in the RH engine compartment.
- Chevrolet Impala / Monte Carlo / Buick LaCrosse (2006-2011): Positioned under the lower air cleaner housing.
- Pontiac G6 / Saturn Aura / Chevrolet Malibu (2006-2010): Located on the LH frame rail or strut tower.
- …and many more models including the HHR, Cobalt, DTS, Rainier, and Hummer H3.
Frequently Asked Questions
Do I need to take my vehicle to the dealership for programming?
Absolutely not. We program the module to your vehicle’s VIN before it ships. This makes the installation plug-and-play, saving you time and money.
What is a ‘core charge’?
There is no core charge for this part. You are not required to send your old, faulty module back to us, which simplifies the process for you.
Will this fix a P0700 transmission code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While this module often resolves the root cause of a P0700, it’s always best to scan for more specific codes (like P0753) to confirm the diagnosis. A faulty TCM is a very common reason for this code.
How long does installation take?
For most DIYers with basic tools, the installation can be completed in under 30 minutes. The most time-consuming part is often just locating the module in a crowded engine bay.
Is there a warranty included?
Yes, this part comes with a one-year warranty, giving you peace of mind and confidence in your repair.