Is Your GMC Envoy Shifting Erratically?
If you’re dealing with the frustration of a GMC Envoy that slams into gear, refuses to shift, or is stuck in limp mode, you know how quickly it can ruin your driving experience. In my 20+ years as a technician, I’ve seen countless GM vehicles, especially SUVs like the Envoy and Trailblazer, come into the shop with these exact issues. The driver often fears the worstโa complete transmission failure. But more often than not, the culprit isn’t the expensive mechanical hardware; it’s the brain behind the operation: the T42 Transmission Control Module (TCM).
“A customer’s 2007 Envoy came in last week with these exact symptomsโa P0700 code and it was stuck in 3rd gear. He had already received a quote for over $3,000 for a transmission rebuild. Before going down that road, we checked the basics. The fluid was clean, and the wiring harness looked good. On a hunch, we swapped in a programmed TCM. In less than an hour, the Envoy was shifting perfectly. The original transmission was fine; the module was simply failing to command the shifts correctly. It’s a common scenario that can save you thousands.”
Symptoms of a Failing T42 TCM in Your Envoy
A failing transmission module can manifest in several ways. If you’re experiencing any of the following, your TCM is the likely cause:
- โ Harsh, delayed, or unpredictable gear shifts.
- โ The vehicle is stuck in a single gear (limp mode) to prevent further damage.
- โ Check Engine Light or Transmission Warning Light is illuminated on the dash.
- โ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults are stored.
- โ A noticeable drop in fuel economy due to inefficient shifting.
- โ Complete loss of communication with the transmission, leading to a no-start or no-shift condition.
Why Choose Our 2006-2009 Envoy Transmission Module?
This isn’t just a replacement part; it’s a complete, ready-to-install solution designed to get your vehicle back to factory performance without the hassle.
- โ VIN Programmed for Your Vehicle: We program the module with your vehicle’s specific VIN and the latest GM software updates before it ships. This ensures it communicates perfectly with your Envoy’s engine computer and other systems right out of the box.
- โ No Dealership Required: Because the programming is done for you, you can skip the expensive trip to the dealer for flashing or calibration. This is a true plug-and-play fix.
- โ Restored Performance: A new TCM restores precise control over shift points, torque converter clutch engagement, and line pressure, resulting in a smoother ride and improved powertrain longevity.
- โ OEM-Quality and Reliability: Built to meet or exceed original equipment specifications, this module is backed by a one-year warranty for your peace of mind.
Plug-and-Play Installation: No Dealer Visit Required
For the 2006-2009 GMC Envoy, this is a straightforward repair you can do in your own driveway in under 30 minutes. The module is typically easy to access.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the vehicle’s computer systems.
- Locate the Module: On the Envoy, the TCM is located in the engine compartment on the driver’s side (LH side). It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unclip the electrical connectors. Use a socket wrench to remove the bolts or nuts holding the module to its bracket.
- Install the New Module: Mount the new, pre-programmed module in the same location and securely fasten it. Reconnect the electrical connectors, ensuring they click into place.
- Final Steps: Reconnect the battery terminal. While the module is pre-programmed, it’s always a good practice to use a basic OBD2 scan tool to clear any old fault codes from the system’s memory.
Guaranteed Fitment and Compatibility
This T42 TCM is a direct replacement for part number 24235753 and is interchangeable with a wide range of other service numbers, including: 24242391, 24234503, 24252114, 24230461, 24234274, 24235340, 24235754, 24238856, 24239224, 24239926, 24240400, 24241806, 24243901, 24243921, 24255280, 24256960, 24235732, and 24240449. It is designed for a vast array of GM vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. Don’t let a faulty module keep your Envoy off the road. Order today and restore the smooth, reliable performance you expect.