Fix Your Envoy’s Shifting Problems with a Plug-and-Play Solution
If your 2006, 2007, 2008, or 2009 GMC Envoy is suffering from harsh shifts, getting stuck in gear, or throwing transmission codes, you’ve likely pinpointed the culprit: a failing Transmission Control Module (TCM). As the electronic brain of your automatic transmission, the TCM is responsible for every gear change. When it falters, it can make your reliable SUV feel unpredictable and unsafe. This T42-style TCM, part number 24230461, is the definitive, hassle-free solution. We pre-program it to your vehicle’s specific VIN, ensuring it works perfectly right out of the box—no expensive trip to the dealership required.
Case Study: A Tricky Diagnosis
I once had a 2008 Envoy in my bay that was giving the owner fits. The transmission would shift perfectly for days, then suddenly start banging into gear and get stuck in 3rd (limp mode). The check engine light was intermittent. The owner had already replaced two shift solenoids at another shop with no success. After hooking up my scan tool and monitoring live data, I noticed the TCM was intermittently losing communication—a classic sign of internal circuit failure that only appeared when the module got hot. A new, properly programmed TCM fixed it permanently. This is a common failure I’ve seen hundreds of times on these GM platforms; heat and vibration eventually take their toll on the electronics.
Is Your GMC Envoy Showing These Signs?
A faulty TCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indication that your module needs replacement. This isn’t just a performance issue; it’s a matter of reliability and safety.
- ✔ Harsh, erratic, or delayed gear shifting.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700 (Transmission Control System Malfunction), P0750-series solenoid codes, or U-series communication codes.
- ✔ Poor fuel economy and a feeling of sluggish performance.
- ✔ The transmission seems to slip or fails to engage a gear.
A Straightforward Guide to Installation
One of the best features of this module is its ease of installation. Because we handle the programming, you can perform the swap yourself in under 30 minutes with basic hand tools. For the 2006-2009 Envoy TCM, you’ll find it in the engine bay.
- 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 the GMC Envoy, the TCM is typically found in the left-hand (driver’s side) of the engine compartment.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly. 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. While the module is plug-and-play, it’s good practice to use a scan tool to clear any stored DTCs from the system after installation.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24230461 and other interchangeable numbers. While this page focuses on the GMC Envoy, this part fits a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. Please verify your part number before ordering.
- GMC Envoy: 2006-2009 (8-Cylinder & All Trims)
- Chevrolet Trailblazer: 2006-2009 (8-Cylinder & All Trims)
- Chevrolet Silverado & GMC Sierra: 2007-2013 (Check specific options)
- Chevrolet Tahoe & GMC Yukon: 2007-2009 (Check specific options)
- Chevrolet Impala & Monte Carlo: 2006-2011
- Pontiac G6 & Grand Prix: 2006-2010
- And many more GM models from 2006-2014.
Do I need to do any programming myself?
Do I need to do any programming myself?
No. This Transmission Control Module comes fully programmed to your vehicle’s VIN. It is a true plug-and-play solution, saving you the time and expense of a dealership visit. Just provide your VIN at checkout.
What is the difference between a TCM and a PCM?
The TCM (Transmission Control Module) exclusively manages the automatic transmission’s functions, like shifting. The PCM (Powertrain Control Module) is a more integrated unit that controls both the engine and transmission. Your vehicle has a separate TCM, which is what this part replaces.
Where is the 2006-2009 Envoy TCM located?
On the 2006-2009 GMC Envoy, the TCM is located in the engine compartment on the driver’s side (LH side).
Is there a core charge for this part?
No, we do not require a core charge. You can keep your old part, which saves you the hassle and cost of shipping it back.
Will this fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While a failing TCM is a very common cause, the issue could also be a sensor or solenoid. However, if you are also experiencing erratic shifting or limp mode, replacing the TCM is the most likely solution.