Restore Peak Transmission Performance to Your GMC Envoy
Is your 2006, 2007, 2008, or 2009 GMC Envoy suffering from erratic shifting, getting stuck in gear, or displaying a check engine light? These are classic signs of a failing Transmission Control Module (TCM). The TCM is the electronic brain of your automatic transmission, responsible for orchestrating every gear change, managing torque converter lockup, and ensuring smooth, efficient operation. When it fails, it can leave you stranded or cause unsafe driving conditions. This OEM-quality T42 TCM, service part number 24234274, is the definitive solution to restore your vehicle’s drivability and reliability.
From the Diagnostic Bay
We had a 2008 GMC Envoy come into the shop with a classic complaint: harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode). The customer had already replaced two shift solenoids based on some forum advice, but the problem persisted. A quick scan showed a P0700 (Transmission Control System Malfunction) code. Instead of just throwing more parts at it, we monitored the TCM data stream. We saw erratic voltage readings from the module itself, confirming our suspicion. The internal electronics were failing. We installed one of our VIN-programmed T42 modules, cleared the codes, and the Envoy shifted like it just rolled off the assembly line. It’s a great reminder that sometimes the controller, not the component, is the root cause.
Symptoms of a Failing 2006-2009 Envoy Transmission Module
A faulty TCM can manifest in several ways, often mistaken for internal transmission failure. Before considering a costly transmission replacement, check if your Envoy is exhibiting any of these common symptoms:
- ✔️ Harsh or Delayed Shifting: Experiencing jarring shifts between gears or a noticeable delay when moving from Park to Drive or Reverse.
- ✔️ Stuck in Limp Mode: The vehicle refuses to shift out of a single gear (usually 2nd or 3rd) to prevent further damage.
- ✔️ Warning Lights: The Check Engine Light or a dedicated transmission warning light is illuminated on your dashboard.
- ✔️ Diagnostic Trouble Codes (DTCs): Common codes like P0700, P0750, or other solenoid-specific codes are stored in the vehicle’s computer.
- ✔️ Poor Fuel Economy: Inefficient shifting and torque converter operation can lead to a sudden drop in your vehicle’s MPG.
- ✔️ Complete Loss of Shifting: In severe cases, the transmission may not shift at all, rendering the vehicle immobile.
The Plug-and-Play Advantage: VIN-Programmed for Your Envoy
Forget expensive trips to the dealership for programming. This T42 Transmission Control Module arrives at your door pre-programmed to your vehicle’s specific Vehicle Identification Number (VIN). We load the latest GM software updates, ensuring that the module communicates flawlessly with your Envoy’s Engine Control Module (ECM) and other systems right out of the box. This critical step eliminates compatibility issues, optimizes shift points and hydraulic pressures for your specific vehicle configuration, and makes installation a true plug-and-play process for you or your mechanic.
This module is a direct replacement for a wide range of part numbers, including 24252114, 24234503, 24230461, 24235340, and many more, making it a versatile solution for numerous GM vehicles beyond the Envoy, such as the Chevrolet Trailblazer, Saab 9-7X, and Buick Rainier.
Simple Installation to Get You Back on the Road
Replacing the TCM on your 2006-2009 Envoy is a straightforward job that can typically be completed in under 30 minutes with basic hand tools. The module is conveniently located in the engine compartment on the left-hand (driver’s) side.
- Safety First: Always disconnect the negative terminal of your vehicle’s battery before beginning work.
- Locate the Module: Find the TCM on the LH side of the engine bay.
- Disconnect and Remove: Carefully unplug the electrical connectors and unbolt the old module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses.
- Final Steps: Reconnect the battery. While the module is plug-and-play, it’s good practice to use a scan tool to clear any old DTCs from the system’s memory.
With no core charge, you can keep your old part without the hassle of returns. Restore the smooth, reliable performance your GMC was built for. Order your VIN-programmed T42 TCM today!
Frequently Asked Questions
What does the T42 Transmission Control Module do on my Envoy?
The T42 TCM is the central computer for your automatic transmission. It processes data from various sensors (like vehicle speed and engine load) to control shift solenoids, manage hydraulic pressure, and engage the torque converter clutch, ensuring smooth and efficient gear changes.
Will I need to take my vehicle to a dealer for programming?
No. This module comes fully pre-programmed to your vehicle’s VIN. This means it is ready for installation right out of the box, with no additional flashing or programming required. This saves you time and the significant expense of dealership labor.
Where is the TCM located on a 2006-2009 GMC Envoy?
On the 2006-2009 GMC Envoy, as well as similar models like the Trailblazer and Rainier, the Transmission Control Module is typically found in the engine compartment on the driver’s side (LH side).
Can a bad TCM prevent my Envoy from moving?
Yes, absolutely. A completely failed TCM can result in a no-shift condition, where the transmission will not engage any gear, effectively immobilizing the vehicle. It can also cause the vehicle to be stuck in limp mode, severely limiting its drivability.
Is this part compatible with other GM vehicles?
Yes, this T42 TCM is compatible with a vast range of 2006-2014 GM vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. This includes many trucks, SUVs, and cars such as the Chevrolet Silverado, Tahoe, Impala, GMC Sierra, and Cadillac DTS. We program it specifically for the vehicle you order it for.