Restore Your Envoy’s Smooth Shifting and Reliability
If you’re dealing with the frustration of a transmission that won’t shift correctly, bangs into gear, or has left you stranded 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 countless GM vehicles, from hardworking Silverados to family-hauling Envoys, sidelined by a failed Transmission Control Module (TCM). This isn’t just an inconvenience; it’s a critical failure that compromises your vehicle’s performance and safety. This T42 TCM, part number 24234274, is the definitive, hassle-free solution to get your 2006 Envoy XL driving like new again.
The core of the problem with these modules is often internal electronic failure, leading to poor communication with the transmission’s solenoids. The result is the erratic behavior you’re likely experiencing. Our module is the answer, arriving at your door pre-programmed to your vehicle’s specific VIN. This means no expensive trips to the dealership for programming—it’s a true plug-and-play fix that you or your mechanic can perform in minutes, not hours.
A Technician’s Notebook: The Intermittent Shifting Ghost
A customer brought in a 2007 Sierra with a complaint that drove him crazy: it would shift perfectly for days, then suddenly start slamming into gear or refuse to shift out of 2nd. He’d already replaced a shift solenoid with no luck. After hooking up my scan tool, I saw a history of intermittent communication loss codes with the TCM. In my shop, I’ve diagnosed hundreds of these T42 TCM failures. The solder joints on the board can develop micro-fractures from years of heat cycles, causing these ghost-like issues. We installed one of our VIN-programmed modules, and the truck’s shifting was immediately smooth and predictable. The customer was thrilled to have a reliable truck again without paying dealership diagnostic and programming fees.
Is Your Envoy Showing These Telltale Signs of TCM Failure?
A faulty TCM can manifest in several ways. If your vehicle is experiencing any of the following, a failing module is the most likely culprit. This 2006 Envoy XL TCM is designed to resolve these exact issues.
- ✔ Harsh, erratic, or delayed gear shifts.
- ✔ Vehicle is stuck in one gear (often called “limp mode”).
- ✔ Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750-P0758 (solenoid circuit faults), or U-series communication codes.
- ✔ The transmission feels like it’s slipping or failing to engage properly.
- ✔ A noticeable decrease in fuel economy.
A Straightforward Guide to a 30-Minute Fix
One of the best features of this module is its simple installation. You don’t need a vehicle lift or specialized tools, saving you significant labor costs. For the 2006 Envoy XL, the TCM is typically located in the left-hand (driver’s side) engine compartment.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the system.
- Locate the TCM: Find the module in the engine bay. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug 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. You’ll hear a click as they lock in.
- Reconnect and Verify: Reconnect the battery terminal. Start the vehicle and ensure the check engine light is off and the transmission shifts smoothly through all gears. We recommend using a basic scan tool to clear any stored historical codes.
Verified Vehicle Compatibility
This T42 TCM is a direct-fit replacement for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. While this page focuses on the 2006 Envoy XL TCM, it is also compatible with the following models. Please verify your specific model and options.
Interchangeable Part Numbers: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, 24239224, 24239926, 24240400, 24241806, 24243901, 24243921, 24255280, 24256960, and more.
Fits select models of: Chevrolet Tahoe, Silverado, Express, Impala, Cobalt, HHR; GMC Yukon, Sierra, Savana; Buick LaCrosse, Lucerne; Cadillac DTS; Pontiac G6, Grand Prix; Saturn Vue, Ion; Hummer H3; Saab 9-7X, and your 2006 GMC Envoy XL (8 cylinder, LH engine compartment).
Frequently Asked Questions
Frequently Asked Questions
Do I need to take this part to a dealer for programming?
No. This module comes fully programmed to your vehicle’s VIN. It is a plug-and-play installation that requires no additional programming or calibration.
What does “No Core Charge” mean?
It means you do not have to send your old, faulty part back to us. This saves you the hassle and cost of return shipping and eliminates any core deposit fees.
How do I find my VIN to provide for programming?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on a plate on the driver’s side dashboard visible through the windshield.
What is the warranty on this TCM?
This transmission control module is backed by our one-year warranty, giving you peace of mind and confidence in your repair.
Will this fix a P0700 trouble code?
Yes. A P0700 code is a general transmission fault request, often triggered by the TCM when it detects a problem. Replacing a faulty TCM is the correct fix for this code when other specific solenoid or sensor codes point to an internal module failure.