If you’re dealing with erratic shifting, a check engine light, or your truck being stuck in limp mode, you know how frustrating a failing Transmission Control Module (TCM) can be. As a technician with over two decades of experience, I’ve seen firsthand how a faulty TCM can sideline a perfectly good GMC Sierra. This isn’t just an inconvenience; it affects your truck’s reliability and your peace of mind. That’s why we offer this direct-fit, VIN-programmed T42 Transmission Control Module, designed to get your 2007-2013 Sierra 1500 TCM functioning like new again, without a costly trip to the dealer.
The TCM is the brain of your automatic transmission, controlling everything from shift points to torque converter lockup. When it fails, the symptoms can often be mistaken for a catastrophic transmission failure, leading to unnecessary and expensive repair quotes. This module is the precise solution for those electronic issues, restoring crisp, predictable shifting and overall performance.
Case Study: A Tricky Diagnosis
A customer brought in his ’09 Sierra 1500, convinced his 4L60E transmission was shot. It was slamming into gear and occasionally wouldn’t shift past 2nd. His local shop quoted him over $3,000 for a rebuild. I hooked up my scanner and found a P0752 (Shift Solenoid ‘A’ Stuck On) and the infamous P0700 (Transmission Control System Malfunction). In my experience, seeing both codes together often points away from a purely mechanical failure. Instead of tearing down the transmission, we swapped in a VIN-programmed TCM. In less than an hour, the codes were gone, and the truck was shifting perfectly. He saved thousands by correctly diagnosing an electronic failure, not a mechanical one. This is the exact fix that got him back on the road.
Is Your Sierra Exhibiting These Transmission Faults?
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ The vehicle is stuck in a single gear (often called ‘limp mode’).
- ✔ An illuminated Check Engine Light or Transmission Warning Light.
- ✔ Diagnostic Trouble Codes (DTCs) stored, such as P0700, P0750-P0758, or other solenoid-related faults.
- ✔ Inconsistent shifting, poor fuel economy, or a feeling of the transmission ‘slipping’.
- ✔ Complete loss of communication with the transmission module.
DIY Installation: Get Your Truck Shifting Smoothly in Under 30 Minutes
One of the biggest benefits of this module is the simple, straightforward installation. You don’t need a hydraulic lift or specialized transmission tools. Because we program it to your truck’s VIN before shipping, it’s a true plug-and-play solution.
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On most 2007-2013 Sierra 1500 models, the TCM is conveniently located in the engine bay, right next to the battery.
- Disconnect and Remove: Carefully unclip the electrical connectors from the old TCM. Then, unbolt the module from its mounting bracket. A basic socket set is all you’ll need.
- Install the New TCM: Mount the new module onto the bracket and securely re-attach the electrical connectors. You’ll hear a click when they are properly seated.
- Final Steps: Reconnect the battery terminal. Start the truck and allow it to idle for a few minutes. If you have a basic scan tool, it’s a good practice to clear any lingering fault codes. Take it for a test drive to confirm smooth operation.
Verified Fitment For Your Vehicle
This T42 TCM is a direct replacement for part number 24234274 and is compatible with a wide range of General Motors vehicles. While it is a guaranteed fit for the specified Sierra models, it also fits other trucks and SUVs. Here is a partial list of confirmed applications:
- GMC Sierra 1500 Pickup: 2007 (New Body Style), 2008, 2009-2013 (w/o hybrid) – Located next to battery.
- Chevrolet Silverado 1500 Pickup: 2007 (New Body Style), 2008, 2009-2013 (w/o hybrid) – Located next to battery.
- Chevrolet Tahoe / GMC Yukon: 2007-2009 – Located next to battery.
- Chevrolet Avalanche 1500 / Suburban 1500: 2007-2008 – Located next to battery.
- GMC Canyon / Chevrolet Colorado: 2008-2012 – Located at RH rear of engine compartment.
- Hummer H3: 2008-2010 – Located at RH rear of engine compartment.
This module also interchanges with part numbers: 24252114, 24234503, 24230461, 24235340, 24239224, 24256960, and more.
Frequently Asked Questions
What does ‘VIN Programmed’ mean for my installation?
It means we load your truck’s specific Vehicle Identification Number (VIN) and the latest GM software onto the module before we ship it. This ensures it communicates perfectly with your vehicle’s engine computer and other systems right out of the box, eliminating the need for expensive dealership programming.
Will this fix a P0700 transmission code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While this module often resolves the root cause (like a faulty solenoid driver), you should ensure any related codes are diagnosed. In many cases I’ve seen, replacing the faulty TCM clears the P0700 and the specific codes that triggered it.
Is this part difficult for a DIYer to install?
Not at all. For the Sierra 1500, the TCM is typically mounted next to the battery, making it one of the easier modules to access and replace. With basic hand tools, most people can complete the job in under 30 minutes.
Do I need to send my old TCM back (core charge)?
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 return shipping.
What kind of warranty is included?
This module comes with a one-year warranty, giving you confidence in the quality and durability of your repair.
Will this work for my 4L60E, 4L65E, or 4L70E transmission?
Yes, this T42 TCM is the correct controller for these common 4-speed automatic transmissions used across the GM truck and SUV lineup during these years.