Restore Smooth Shifting to Your 2006 GMC Envoy XL
If your 2006 GMC Envoy XL is suffering from harsh shifting, getting stuck in gear, or throwing transmission codes, you’ve likely pinpointed the culprit: a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen firsthand how a faulty TCM can sideline an otherwise reliable SUV. This isn’t just an annoyance; it’s a critical failure that compromises drivability and safety. This OEM-quality T42 TCM, corresponding to part number 24238856, is the definitive solution, arriving expertly programmed to your vehicle’s specific VIN for a true plug-and-play repair.
The TCM is the brain of your automatic transmission, managing everything from shift points and line pressure to torque converter lockup. When it fails, the communication between your engine and transmission breaks down, leading to the frustrating symptoms you’re experiencing. Our VIN programming service eliminates the need for expensive dealership visits and complex flashing procedures. We load the latest GM software onto the module using your VIN, ensuring it works perfectly with your 2006 Envoy XL TCM system right out of the box.
Case Study: A Tricky Diagnosis
A customer brought in their ’06 Envoy XL with the 5.3L V8. The complaint was intermittent harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode), with a P0700 code stored. We checked the fluid and solenoids, which were fine. Experience pointed directly to the TCM, a common failure point due to heat and vibration in the engine bay. Instead of a costly dealer part and programming fee, we installed one of our pre-programmed modules. The entire job took less than 20 minutes, and a test drive confirmed all shift patterns were back to factory-smooth operation. The customer saved hundreds and was back on the road the same day.
Is Your Envoy XL Showing These Telltale Signs?
- ✔ Abrupt, jerky, or delayed gear shifts that make driving uncomfortable.
- ✔ The vehicle enters “limp mode,” refusing to shift out of a single gear (often 2nd or 3rd).
- ✔ Check Engine Light or Transmission Warning Light is illuminated on the dash.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750-series solenoid codes, or communication errors.
- ✔ A noticeable drop in fuel economy due to inefficient shifting.
- ✔ The transmission seems to slip or fails to engage a gear properly.
A Straightforward Guide to Installation
Replacing the TCM on your Envoy XL is a job most DIYers can handle in their own driveway. For the 2006 GMC Envoy XL with the 8-cylinder engine, the module is conveniently located in the left-hand (driver’s side) engine compartment, making access simple.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the vehicle’s computer systems.
- Locate the Module: Find the TCM on the driver’s side of the engine bay. It’s a silver box with several large electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses. They have locking tabs that need to be released. Once disconnected, unbolt the module from its mounting bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place. Securely plug in the electrical connectors until they click, ensuring a solid connection.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the vehicle and let it idle for a few minutes. Use a basic OBD2 scanner to clear any stored fault codes and take the vehicle for a test drive to confirm the shifting issues are resolved.
Verified Vehicle Compatibility
This T42 Transmission Control Module is a direct-fit replacement for a wide range of General Motors vehicles. While this page focuses on the 2006 Envoy XL TCM, it is also compatible with the following models and configurations. Please verify your specific application.
- ENVOY XL 06 Transmission; (LH engine compartment), (8 cylinder)
- ENVOY 06-09 Transmission; (LH engine compartment)
- TRAILBLAZER & EXT 06-09 Transmission; (LH engine compartment), (8 cylinder)
- CHEVROLET SILVERADO & GMC SIERRA 1500/2500 07-13 Transmission; (next to battery)
- CHEVROLET TAHOE & GMC YUKON 07-09 Transmission; (next to battery)
- CADILLAC DTS 06-11 Transmission; (RH front engine compartment)
- BUICK LACROSSE / ALLURE 06-09 Transmission; (lower air cleaner housing)
- CHEVROLET IMPALA 06-11 Transmission; (lower air cleaner housing)
- PONTIAC G6 06-10 Transmission; (LH strut tower)
- SATURN VUE / AURA 07-10 Transmission
- …and many other GM models from 2006-2014. This part interchanges with numbers 24252114, 24234503, 24238856, and more.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
It means we flash the module with your vehicle’s unique 17-digit Vehicle Identification Number (VIN) and the latest GM-certified software before shipping. This ensures the TCM communicates perfectly with your Envoy’s engine and other systems, making installation plug-and-play with no extra programming required.
Will this fix my check engine light and P0700 code?
If the root cause of your check engine light and codes like P0700 (Transmission Control System Malfunction) is a faulty TCM, then yes, this part is the direct solution. After installation, you should clear the codes with a scanner.
Is this a difficult part to install for a DIYer?
Not at all. For the 2006 Envoy XL, the location in the engine bay is easy to access. With basic hand tools and our guide, most people can complete the swap in under 30 minutes. It’s one of the easier electronic component replacements.
Do I need to send my old part back? Is there a core charge?
No. We do not require a core return for this module. You can keep your old part, which simplifies the process and saves you the hassle and cost of return shipping.
What kind of warranty comes with this TCM?
This transmission control module is backed by our comprehensive one-year, hassle-free warranty, giving you confidence and peace of mind in your repair.