VIN Programmed 2006 Envoy XL TCM 24239926 | T42 Transmission Module

If you’re dealing with the headache of a transmission that won’t shift correctly, warning lights on the dash, or a 2006 GMC Envoy XL that’s stuck in limp mode, you’ve come to the right place. As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Transmission Control Module (TCM) can bring a perfectly good vehicle to a standstill. This isn’t just an inconvenience; it’s a critical failure that compromises safety and driveability. This T42 TCM, part number 24239926, is the reliable, straightforward solution you need.

The TCM is the brain of your automatic transmission, constantly communicating with the engine computer to manage shift points, torque converter clutch engagement, and line pressure. When it fails, the signals get crossed, leading to the jarring shifts, delayed engagement, and poor performance you’re likely experiencing. Our module is meticulously prepared and programmed to your vehicle’s specific VIN, ensuring it works perfectly right out of the box—no expensive trips to the dealership for programming are necessary.

Is Your Envoy XL Showing These Telltale Signs?

A failing TCM often gives clear warnings. If you’re noticing any of the following, it’s a strong indicator that your module needs replacement. Ignoring these can lead to more severe transmission damage.

• ✔ Harsh, erratic, or delayed gear shifts that make driving uncomfortable.
• ✔ Vehicle is stuck in a single gear (often called “limp mode”) and won’t upshift or downshift.
• ✔ The Check Engine Light or a dedicated transmission warning light is illuminated.
• ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
• ✔ A noticeable drop in fuel economy as the transmission operates inefficiently.
• ✔ Complete loss of communication with the TCM, preventing diagnostics and causing total transmission failure.

A Straightforward Guide to Installing Your 2006 Envoy XL TCM

One of the best parts about this solution is its simplicity. This is a job most DIYers can handle with basic hand tools in their own driveway.

1. Safety First: Before you begin, disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the vehicle’s computer systems.
2. Locate the Module: On your 2006 Envoy XL (with the 8-cylinder engine), the TCM is typically found in the engine compartment on the left-hand (driver’s) side. Check near the firewall or inner fender.
3. Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. Press the release tabs firmly to avoid breaking them. Then, unbolt the module from its mounting bracket.
4. Install the New Module: Mount your new, pre-programmed TCM in the same location and securely fasten it. Reconnect the electrical connectors, ensuring they click into place.
5. Final Steps: Reconnect the negative battery terminal. While the system may reset, it’s best practice to use a basic OBD-II scan tool to clear any stored fault codes from the computer’s memory. Start the vehicle and take it for a test drive to confirm smooth shifting.

Verified Vehicle Compatibility

This T42 TCM is a direct replacement for a wide range of General Motors vehicles. While this listing is for the 2006 Envoy XL, it is also compatible with the following models. Always verify your part number (24239926) or check the interchange list for a perfect match.

Frequently Asked Questions