End Your Transmission Frustrations and Get Back on the Road
If you’re dealing with the headaches of a failing transmission in your 2006 GMC Envoy XL—like sudden, violent shifts, getting stuck in gear, or a persistent check engine light—you know how disruptive it can be. As a technician with over two decades of experience, I’ve seen countless GM vehicles sidelined by faulty Transmission Control Modules (TCMs). The T42 module is the electronic brain of your automatic transmission, and when it fails, it can mimic a catastrophic mechanical failure, leading to costly misdiagnoses. This VIN-programmed T42 TCM, part number 24255280, is the reliable, straightforward solution to restore your vehicle’s performance and your peace of mind.
Case Study: A Tricky Diagnosis
A customer brought in his 2007 Silverado with classic transmission failure symptoms: harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode), with a P0700 code stored. He was convinced his 4L60E transmission needed a full rebuild, a multi-thousand dollar job. After hooking up my scan tool, I noticed erratic data from the shift solenoids. Instead of jumping to a rebuild, I inspected the TCM. After seeing no external issues, we swapped in a pre-programmed T42 module. Within 30 minutes, the truck was shifting like it just left the factory. It saved the customer a huge amount of money and downtime—a perfect example of how correctly diagnosing this module is key.
Is Your Envoy Exhibiting These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission failure is imminent. Often, the signs are electronic. If you’re experiencing any of the following, your TCM is the likely culprit, especially if you have Diagnostic Trouble Codes (DTCs) like P0700, P0750-P0758, or other solenoid-related faults.
- ✔ Abrupt, harsh, or jerky gear shifts.
- ✔ The vehicle is stuck in a single gear (often called “limp mode”).
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ Illumination of the Check Engine Light or Transmission Warning Light.
- ✔ Inability to upshift or downshift properly.
- ✔ A noticeable drop in fuel economy.
- ✔ Complete loss of communication with the module, preventing diagnostics.
Your Straightforward 30-Minute Installation Guide
One of the best features of this module is that it’s designed for a hassle-free installation that most DIYers can handle. By providing us with your VIN, we program the module before it ships, so it’s ready to install right out of the box—no expensive trip to the dealership required.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On your 2006 Envoy XL, the TCM is typically found in the engine compartment on the left-hand (driver’s) side. Check near the firewall or strut tower.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly to avoid breaking them. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses. You should hear a click as they lock in.
- Final Steps: Reconnect the battery terminal. Start the vehicle and allow it to idle for a few minutes. If you have a basic scan tool, use it to clear any stored fault codes from the computer’s memory.
The Definitive Solution for Your Transmission
This isn’t just a replacement part; it’s a permanent fix for common GM transmission issues. This 2006 Envoy XL Transmission Module is engineered to meet or exceed original equipment specifications, ensuring long-term reliability for your vehicle.
- ✔ Plug-and-Play VIN Programming: We flash the module with your vehicle’s specific VIN and the latest GM software updates. This ensures perfect communication with the Engine Control Module (ECM) and other vehicle systems for optimal shift strategy and performance.
- ✔ Restored Performance: By precisely controlling shift points, line pressure, and torque converter lockup, this module restores the smooth, efficient operation you expect from your transmission.
- ✔ No Core Charge: Keep your old part. There’s no need to worry about the hassle and expense of returning a core.
- ✔ Guaranteed Quality: Backed by our one-year warranty, you can install this part with confidence, knowing it’s built to last.
Verified Fitment Across a Range of GM Vehicles
While this is the ideal 2006 Envoy XL Transmission Module, the T42 platform was used across a wide array of General Motors cars, trucks, and SUVs. It is a direct replacement for part numbers 24255280, 24252114, 24234503, and others listed below. Please verify your specific model and year.
- GMC: Envoy (06-09), Envoy XL (06), Sierra 1500/2500 (07-13), Yukon (07-09), Yukon XL 1500 (07-08), Savana 1500/2500/3500 (06-14), Canyon (08-12)
- Chevrolet: Silverado 1500/2500 (07-13), Tahoe (07-09), Suburban 1500 (07-08), Avalanche 1500 (07-08), Express 1500/2500/3500 (06-14), Impala (06-11), Monte Carlo (06-07), HHR (06-11), Cobalt (06-10), Colorado (08-12), Malibu (06-10), SSR (05-06), Trailblazer (06-09)
- Buick: LaCrosse (06-09), Lucerne (06-11), Allure (06-09), Rainier (06-07), Rendezvous (06-07)
- Cadillac: DTS (06-11)
- Pontiac: G6 (06-10), G5 (07-10), Grand Prix (06-08), Pursuit (06)
- Saturn: Vue (07-10), Aura (07-09), Ion (06-07)
- Hummer: H3 (08-10)
- Saab: 9-7X (06-09)
Frequently Asked Questions
Frequently Asked Questions
What is VIN programming and why do I need it?
VIN programming loads your vehicle’s unique identification number and factory software onto the module. This is critical for the TCM to communicate correctly with your engine and other systems. Our pre-programming service means the part is ready for installation out of the box, saving you a trip and programming fees at a dealership.
Will this module fix a P0700 trouble code?
A P0700 code is a general transmission fault request from the TCM to the ECM to turn on the check engine light. While this module often resolves the underlying issue causing the P0700 (like a bad solenoid driver), you should have the specific transmission codes read (e.g., P0752, P0757) to confirm the TCM is the root cause.
Is any special relearn procedure needed after installation?
No, a complex relearn procedure is not typically required. After installing the pre-programmed module and reconnecting the battery, the system will self-calibrate as you drive. For best results, drive moderately for the first 20-30 miles, allowing the transmission to adapt to the new module’s precise commands.
Is this a new or used part?
This is a high-quality, inspected component built to meet stringent OEM standards for performance and reliability. It is not a new part from the original manufacturer but is guaranteed to function correctly and is backed by our comprehensive one-year warranty.
Where is the TCM located on my vehicle?
Location varies by model. On the 2006 Envoy XL, it’s on the driver’s side of the engine bay. On Silverado/Sierra trucks, it’s often next to the battery. On cars like the Impala or LaCrosse, it can be under the air cleaner housing. Always confirm the location for your specific vehicle before starting.