Restore Flawless Shifting to Your GMC Truck
Is your 2007 GMC Sierra 2500 experiencing harsh shifting, getting stuck in gear, or throwing transmission codes? A failing Transmission Control Module (TCM) is one of the most common culprits behind these frustrating and potentially damaging issues. As a technician with over two decades of experience, I’ve seen how a faulty TCM can sideline a perfectly good truck. This T42 Transmission Control Module, part number 24235340, is the direct-fit, reliable solution you need. It arrives pre-programmed to your truck’s specific Vehicle Identification Number (VIN), eliminating the need for expensive dealership visits and ensuring a true plug-and-play installation.
A Technician’s Notebook: The Intermittent Shifting Mystery
I once had a 2007 Sierra 2500 HD in my bay with a problem that was driving the owner crazy. The truck would shift perfectly for days, then suddenly start banging into gear or refuse to shift out of 3rd. He’d already replaced a shift solenoid with no luck. The scanner showed a generic P0700 code and an intermittent solenoid circuit code. After checking the wiring, I suspected the TCM. Heat and vibration can cause internal fractures in these modules that only show up under certain conditions. We installed a VIN-programmed 2007 Sierra 2500 TCM, and the problem vanished instantly. It’s a classic case where chasing individual codes can be misleading; the root cause is often the module itself.
Is Your Sierra Exhibiting These Telltale Signs?
A failing TCM doesn’t always mean total transmission failure. Often, it starts with small, annoying symptoms. If you’re noticing any of the following, it’s a strong indicator that your module needs attention:
- ✔ Unpredictable or harsh gear changes, feeling like the transmission is slamming into gear.
- ✔ The vehicle is stuck in “limp mode,” often only allowing access to 2nd or 3rd gear.
- ✔ Your Check Engine Light or a dedicated transmission warning light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, especially P0700 (Transmission Control System Malfunction), P0750, or other solenoid-related codes.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ A noticeable decrease in fuel economy due to inefficient shifting.
Simple 30-Minute Installation Guide
One of the best features of this module is how simple it is to install. You don’t need a lift or specialized tools. For most GMT900 trucks like your Sierra, the process is straightforward.
- Safety First: Always disconnect the negative terminal on your truck’s battery before starting any electrical work.
- Locate the Module: On your 2007 Sierra 2500, the TCM is typically located in the engine bay, right next to the battery. It’s a silver box with electrical connectors.
- 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 plug in the electrical connectors. You’ll hear a click when they’re seated correctly.
- Final Steps: Reconnect your battery terminal. While the module is plug-and-play, it’s always good practice to use a basic scan tool to clear any stored DTCs from the system.
Verified Fitment for Your GM Truck & More
This T42 TCM is the correct replacement for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, 4L70E, and 4L80E. While this page is focused on the 2007 Sierra 2500 TCM, it is also a direct fit for the following models, among others:
- ✔ GMC Sierra 2500 Pickup (2007): New body style, 6.0L, located next to the battery.
- ✔ Chevrolet Silverado 2500 Pickup (2007): New body style, 6.0L, located next to the battery.
- ✔ GMC & Chevrolet 1500 Pickups (2007-2013)
- ✔ Chevrolet Tahoe & GMC Yukon (2007-2009)
- ✔ Chevrolet & GMC Savana/Express Vans (2006-2014)
- ✔ Hummer H3 (2008-2010)
- ✔ Chevrolet Colorado & GMC Canyon (2008-2012)
This module replaces part numbers: 24235340, 24252114, 24234503, 24230461, 24234274, 24235754, and more.
Frequently Asked Questions
What does a VIN-programmed TCM mean for me?
It means the module arrives ready to install right out of the box. We load your vehicle’s specific software onto it using your VIN, so it communicates perfectly with your truck’s engine and other systems without needing a trip to the dealer for expensive programming.
Will this fix a P0700 trouble code?
In many cases, yes. The P0700 code is a general fault code indicating the TCM has detected a problem. If the TCM itself is the source of the failure, replacing it with this new module will resolve the code and the underlying issue.
Is this a difficult part to install myself?
Not at all. For a DIYer with basic hand tools, this is one of the easier electronic component replacements. It’s typically located in an accessible spot in the engine bay and takes less than 30 minutes to swap out.
Do I need to return my old TCM?
No. There is no core charge for this part. You can keep your old module or dispose of it, saving you the hassle and cost of shipping it back.
What transmissions is this T42 module for?
This module is designed for GM vehicles with 4-speed automatic transmissions, including the popular 4L60E, 4L65E, 4L70E, and the heavy-duty 4L80E found in your Sierra 2500 HD.