Finally, A Real Fix for Your GMC Envoy’s Transmission Problems
If you’re dealing with a GMC Envoy that shifts hard, gets stuck in gear, or throws transmission codes, you know how frustrating it can be. As a technician with over 20 years of experience, I’ve seen countless drivers worry they’re facing a multi-thousand dollar transmission rebuild when the real culprit is a failed Transmission Control Module (TCM). This T42 TCM, part number 24234274, is the definitive solution for your 2006-2009 GMC Envoy, designed to restore the crisp, predictable shifting you’ve been missing.
The TCM is the brain of your automatic transmission. It analyzes data from engine speed, vehicle speed, and throttle position sensors to command precise gear changes and manage torque converter lockup. When it fails, communication breaks down, leading to the jarring shifts and poor performance you’re experiencing. Our module solves this by arriving expertly programmed to your vehicle’s specific VIN. This isn’t a generic, one-size-fits-all part; it’s a plug-and-play solution that eliminates the need for an expensive and time-consuming trip to the dealership for programming.
A Technician’s Notebook: The Envoy That Dodged a Rebuild
A customer brought in his 2007 Envoy, convinced the 4L60E transmission was shot. It was slamming into gear and the check engine light was on with a P0750 (Shift Solenoid A Malfunction) code. He’d already gotten a quote for over $3,000 for a transmission replacement. After a quick diagnostic check, I saw the solenoid was receiving erratic voltage commands. The problem wasn’t the transmission’s internal mechanics; it was the TCM. We installed one of our pre-programmed modules, and in less than an hour, the Envoy was shifting like it just rolled off the factory line. He saved thousands and drove away with a reliable vehicle—a classic case of the brain, not the body, being the issue.
Is Your Envoy Exhibiting These Transmission Issues?
A failing TCM can manifest in several ways. If you’re noticing any of the following, it’s a strong indicator that your module is the problem. This is especially true if you have Diagnostic Trouble Codes (DTCs) like P0700 (Transmission Control System Malfunction) or other solenoid-related codes.
- ✔ Hard, slamming shifts or erratic gear changes.
- ✔ The vehicle feels like it’s stuck in one gear (often called “limp mode”).
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ Check Engine Light or a dedicated transmission warning light is illuminated.
- ✔ A noticeable drop in fuel economy.
- ✔ Complete failure to shift up or down.
- ✔ Intermittent loss of communication with the module, causing unpredictable behavior.
Your 30-Minute Path to a Smooth Ride
One of the best features of this module is its straightforward installation. For the average DIYer with basic hand tools, this is a job you can complete in your own driveway in under 30 minutes. Here’s a general guide:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and help reset the system.
- Locate the TCM: On the 2006-2009 GMC Envoy, the TCM is typically found in the engine compartment on the driver’s side (LH side).
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place and securely reconnect the electrical harnesses. Ensure they click into place.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the vehicle and let it idle for a few minutes. If you have a basic scan tool, it’s good practice to clear any stored fault codes.
- Test Drive: Take your Envoy for a drive to confirm that shifting has returned to normal. The vehicle may go through a brief re-learning period as it adapts to the new module.
Why Choose Our Pre-Programmed 2006-2009 Envoy TCM?
This isn’t just a replacement part; it’s a complete repair solution. By programming the module with the latest GM software updates for your specific VIN, we ensure perfect compatibility and optimal transmission performance right out of the box. You get a reliable, OEM-quality component that restores function and peace of mind, all without the dealership hassle. It’s the smart, efficient fix for both professional shops and home mechanics.
Verified Vehicle Compatibility
This T42 Transmission Control Module is a direct fit for the following vehicles and configurations. Please verify your model and location before ordering.
- ENVOY 2006-2007: Transmission; (LH engine compartment), (8 cylinder)
- ENVOY 2008-2009: Transmission; (LH engine compartment)
- ENVOY XL 2006: Transmission; (LH engine compartment), (8 cylinder)
- ALLURE 2006-2009: Transmission; (lower air cleaner housing)
- AVALANCHE 1500 2007-2008: Transmission; (next to battery)
- CANYON 2008-2012: Transmission; (RH rear engine compartment)
- COBALT 2006-2010: Transmission; (LH strut tower)
- COLORADO 2008-2012: Transmission; (RH rear engine compartment)
- DTS 2006-2011: Transmission; (RH front engine compartment)
- EXPRESS/SAVANA VANS (1500, 2500, 3500) 2006-2014: Transmission; (RH engine compartment)
- G6 2006-2010: Transmission; (LH strut tower)
- GRAND PRIX 2006-2008: Transmission; (lower air cleaner housing)
- HHR 2006-2011: Transmission; (LH engine compartment)
- HUMMER H3 2008-2010: Transmission; (RH rear engine compartment)
- IMPALA 2006-2011: Transmission; (lower air cleaner housing)
- LACROSSE 2006-2009: Transmission; (lower air cleaner housing)
- LUCERNE 2006-2011: Transmission; (LH engine compartment)
- MONTE CARLO 2006-2007: Transmission; (lower air cleaner housing)
- RAINIER 2006-2007: Transmission
- SAAB 9-7X 2006-2009: Transmission; (LH engine compartment)
- SIERRA/SILVERADO (1500, 2500) 2007-2013: See specific options in source data.
- TAHOE/YUKON 2007-2009: Transmission; (next to battery)
- TRAILBLAZER 2006-2009: Transmission; (LH engine compartment), (8 cylinder options for 06-07)
- …and many other GM models from 2006-2014.
Do I need to get this module programmed by a dealer?
Do I need to get this module programmed by a dealer?
No. This is the biggest benefit of our service. We program the module to your vehicle’s VIN before shipping it. It arrives ready for plug-and-play installation, saving you hundreds in dealership programming fees.
Is this a difficult part to install myself?
For most people with basic mechanical skills, this is a very manageable DIY job. It’s typically located in an accessible part of the engine bay and requires only common hand tools. The entire process often takes less than 30 minutes.
What if I install it and still have problems?
While this module fixes the vast majority of TCM-related issues, transmission problems can be complex. If issues persist, it could indicate a problem with a solenoid, wiring harness, or internal mechanical part. Our module comes with a one-year warranty, and our expert support team is here to help you diagnose the next steps.
Is there a core charge? Do I need to send my old part back?
No, there is no core charge for this module. You can keep your old part, saving you the time and hassle of shipping it back.
How do I provide my VIN for programming?
You will be prompted to enter your vehicle’s 17-digit VIN during the checkout process. Please double-check it for accuracy to ensure perfect programming.