If you’re dealing with the headaches of a faulty transmission—like harsh, unpredictable shifting or your GMC Envoy being stuck in limp mode—you’ve come to the right place. As a technician with over two decades of experience, I’ve seen firsthand how a failing Transmission Control Module (TCM) can sideline an otherwise reliable vehicle. This isn’t just an inconvenience; it’s a critical failure that affects safety and drivability. This T42 series TCM, part number 24234503, 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, constantly managing shift points, hydraulic pressure, and torque converter lockup. When it starts to fail, often due to internal electronic component breakdown from heat and vibration, the symptoms can be maddeningly intermittent at first. One day it drives fine, the next it’s banging into gear. Replacing it with our pre-programmed module eliminates the guesswork and the expensive trip to the dealership for coding. This is the same reliable fix I’d perform in my own shop to get a customer safely back on the road.
From the Diagnostic Bay: The Case of the Erratic Envoy
A customer brought in their ’07 Envoy, complaining of sudden, violent shifts and a check engine light that would come and go. They were worried they needed a full transmission rebuild. I pulled the codes and saw a P0700 (Transmission Control System Malfunction) and a P0753 (Shift Solenoid ‘A’ Electrical). While a solenoid could be the culprit, my experience with these GM platforms pointed me straight to the TCM. After a quick 20-minute swap with a VIN-programmed module, the codes were cleared, and the test drive was perfectly smooth. We saved the customer thousands and fixed the root cause, not just a symptom.
Is Your Envoy Exhibiting These Telltale Signs?
A failing TCM will give you clear warnings. If you’re noticing any of the following, it’s time for a diagnosis. This module is designed to correct these common issues:
- âś” Harsh, slamming, or delayed gear engagement.
- âś” Vehicle stuck in one gear (often 2nd or 3rd), also known as “limp mode.”
- âś” An illuminated Check Engine Light or Transmission Warning Light.
- âś” Diagnostic Trouble Codes (DTCs) such as P0700, P0750-P0758, or other solenoid-related faults.
- âś” Inability to upshift or downshift correctly, leading to poor acceleration.
- âś” A noticeable drop in fuel economy or signs of the transmission overheating.
A Straightforward Guide to Your TCM Installation
One of the best features of this part is its simple installation. You don’t need to be a master mechanic to get this done in your own driveway in under 30 minutes. This is a common location for the 2006-2009 Envoy Transmission Control Module.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On the GMC Envoy and similar platforms (like the Trailblazer or Saab 9-7X), the TCM is typically found in the engine compartment on the driver’s side (LH side).
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs, so don’t force them. Once disconnected, unbolt the old module from its mounting bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place and securely reconnect the electrical harnesses. You’ll hear a ‘click’ when they’re seated properly.
- Final Steps: Reconnect the battery terminal. While our programming handles the critical setup, it’s good practice to use a basic OBD-II scan tool to clear any stored fault codes from the vehicle’s memory.
Verified Vehicle Compatibility List
This module is a direct-fit replacement for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. Please verify your vehicle is on this list for guaranteed compatibility. It interchanges with part numbers 24252114, 24234503, 24230461, and others.
- GMC Envoy: 2006-2009 (LH engine compartment)
- Chevrolet Trailblazer: 2006-2009 (LH engine compartment)
- Chevrolet Silverado / GMC Sierra 1500: 2007-2013 (Located next to the battery)
- Chevrolet Tahoe / GMC Yukon: 2007-2009 (Located next to the battery)
- Chevrolet Impala: 2006-2011 (Under lower air cleaner housing)
- Hummer H3: 2008-2010 (RH rear engine compartment)
- Saab 9-7X: 2006-2009 (LH engine compartment)
- …and many more GM cars, trucks, and SUVs from 2006-2014. Check the full list to confirm your specific model and year.
Frequently Asked Questions
Do I need to take my vehicle to the dealer for programming?
No. This module comes pre-programmed to your vehicle’s VIN. It’s ready for installation right out of the box, saving you time and hundreds of dollars in dealership fees.
Is this a difficult part for a DIYer to install?
Not at all. With basic hand tools, the swap typically takes less than 30 minutes. The most common locations are easily accessible in the engine bay.
What is a core charge?
There is no core charge for this part. You are not required to send your old, faulty module back to us, which simplifies the process for you.
Will this fix a P0700 check engine light code?
Yes, in a vast majority of cases. A P0700 code is a generic fault indicating the TCM has detected a problem. If the TCM itself is the source of that problem, replacing it with this unit will resolve the code and the underlying issue.
What kind of warranty is included?
This part is backed by our comprehensive one-year warranty, giving you peace of mind and confidence in your repair.