If your 2006-2009 GMC Envoy is suffering from erratic shifting, getting stuck in gear, or has the dreaded check engine light on with transmission codes, you’ve likely pinpointed a failing Transmission Control Module (TCM). As a technician with over two decades of experience under the hood, I can tell you that these T42 modules are a common failure point, but the fix is more straightforward than you might think. Don’t let a faulty module sideline your reliable SUV. This direct-replacement T42 TCM, part number 24241806, is the definitive solution to restore your transmission’s performance and your peace of mind.
The biggest hurdle in replacing a TCM is usually the programming. Dealerships charge a premium for this service, adding time and cost to your repair. We eliminate that step entirely. By providing your vehicle’s VIN at checkout, we program the module with the latest GM software updates specifically for your Envoy. It arrives at your door ready for a true plug-and-play installation, instantly resolving communication errors and restoring crisp, correct shift patterns.
Is Your Envoy Exhibiting These Transmission Problems?
A failing TCM can manifest in several ways, often mistaken for internal transmission failure. Before you consider a costly transmission rebuild, check if you’re experiencing these classic symptoms. Over the years, I’ve diagnosed hundreds of these issues that traced back to the TCM.
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ The vehicle is stuck in ‘limp mode,’ often in 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, or other solenoid-related faults.
- ✔ Inability to upshift or downshift, leading to poor acceleration and fuel economy.
- ✔ Intermittent loss of communication with the module, causing unpredictable performance.
From the Diagnostic Bay: The Intermittent Shifting Ghost
A customer brought in a 2008 Envoy with a complaint that stumped two other shops: it would occasionally refuse to shift out of 2nd gear after being driven for about 20 minutes, but only on warm days. No codes were stored. We monitored live data and saw the TCM would simply stop sending commands to the shift solenoids. Heat soak was causing an internal failure in the module’s circuitry. We installed one of our pre-programmed T42 modules, and the problem was solved instantly. The customer saved hundreds compared to the ‘diagnostic’ parts replacement suggested by others.
Why a Pre-Programmed 2006-2009 Envoy TCM is the Smart Choice
This isn’t just a replacement part; it’s a complete repair solution. By handling the programming, we save you a trip to the dealership and the associated labor costs. This module is built to meet or exceed original equipment standards, ensuring long-term reliability for your 4L60E or 4L65E transmission. It directly manages shift solenoids, torque converter clutch, and line pressure to restore the smooth operation you expect from your vehicle.
Your Straightforward 30-Minute Installation Guide
You don’t need to be a master mechanic to install this part. With basic hand tools, you can get your Envoy back on the road in under an hour.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the TCM: On the 2006-2009 GMC Envoy, the TCM is typically found in the engine compartment on the driver’s side (LH).
- Disconnect and Remove: Carefully unclip the electrical connectors from the old module. Then, unbolt the module from its mounting bracket.
- Install the New Module: Mount your new, pre-programmed TCM onto the bracket and securely reconnect the electrical connectors. You’ll hear a click when they’re seated properly.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s good practice to use a basic scan tool to clear any old fault codes from the vehicle’s memory. Start the vehicle and enjoy your smooth-shifting transmission!
Verified Fitment for Your General Motors Vehicle
This T42 TCM is a direct replacement for part number 24241806 and is compatible with a wide range of GM vehicles. Please verify your model and year below. This part fits the following vehicles with the specified options:
- ENVOY 2006-2007 (8 cylinder), Transmission; (LH engine compartment)
- ENVOY 2008-2009 Transmission; (LH engine compartment)
- ENVOY XL 2006 (8 cylinder), Transmission; (LH engine compartment)
- TRAILBLAZER 2006-2007 (8 cylinder), Transmission; (LH engine compartment)
- TRAILBLAZER 2008-2009 Transmission; (LH engine compartment)
- TRAILBLAZER EXT 2006 (8 cylinder), Transmission; (LH engine compartment)
- And many other GM cars, trucks, and SUVs from 2006-2014.
Frequently Asked Questions
Do I need to take my vehicle to a dealer after installation?
No. This module arrives pre-programmed to your vehicle’s VIN. The installation is complete once it’s plugged in, saving you time and money on dealership programming fees.
What is a core charge? Do I need to send my old part back?
There is absolutely no core charge for this part. You can keep your old module or dispose of it at your convenience without any extra fees or hassle.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the main engine computer (ECM/PCM) to turn on the check engine light. While this module often resolves the underlying issue causing the P0700, it’s important to scan for more specific transmission codes (e.g., P07xx) to confirm the diagnosis.
Is this part difficult to install for a DIYer?
Not at all. The TCM is located in the engine bay and is accessible with basic hand tools. The entire process of swapping the module typically takes less than 30 minutes, making it a very DIY-friendly repair.
What kind of warranty is included?
This module is backed by our one-year, hassle-free warranty, giving you confidence in the quality and durability of your repair.