Restore Your Sierra’s Shifting Performance and Reliability
As a technician with over two decades of experience, I’ve seen firsthand the frustration that comes with a failing transmission control module, especially in a workhorse like the GMC Sierra. One minute your truck is pulling a trailer with ease, and the next, it’s stuck in limp mode, shifting harshly, or refusing to shift at all. The culprit is often a faulty Transmission Control Module (TCM), the electronic brain that manages every aspect of your automatic transmission’s behavior. This VIN-programmed T42 TCM, part number 24240400, is the definitive solution for your 2007-2013 Sierra 1500 TCM issues, designed to get you back on the road without a costly and time-consuming trip to the dealership.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We handle the complex part by programming the module to your truck’s specific Vehicle Identification Number (VIN) before it ships. This ensures it communicates perfectly with your vehicle’s other systems, like the Engine Control Module (ECM), right out of the box. It restores precise shift points, proper torque converter lockup, and accurate diagnostic reporting, effectively resolving those confusing transmission-related error codes.
Is Your Sierra Exhibiting These Telltale Signs?
A failing TCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs attention. In my shop, these are the most common complaints we tie directly to a bad TCM:
- ✔ Abrupt, harsh, or jerky gear changes.
- ✔ The transmission seems to slip between gears or delays engagement from Park to Drive or Reverse.
- ✔ Your truck is stuck in a single gear (often 2nd or 3rd), a condition known as “limp mode.”
- ✔ The Check Engine Light or a specific transmission warning light is illuminated on your dash.
- ✔ Diagnostic scans reveal codes like P0700 (Transmission Control System Malfunction), P0750-P0758 (Shift Solenoid errors), or other communication faults.
- ✔ A noticeable drop in fuel economy or the transmission running hotter than usual.
From the Diagnostic Bay
I remember a 2011 Sierra 1500 that came into the shop towed on a flatbed. The owner, a contractor, was panicked because his truck was completely stuck in what felt like third gear. He couldn’t get any power from a stop and his check engine light was on. His scanner showed a P0700 code. He was worried he was looking at a full transmission rebuild, which would have cost him thousands and put his work on hold. After a quick diagnostic, we confirmed the transmission’s mechanicals were fine; the TCM was the problem. Instead of a multi-day, high-cost repair, we installed a VIN-programmed module just like this one. The whole job took less than an hour, including clearing the codes. He drove out with a perfectly shifting truck, saving himself a massive headache and a significant amount of money.
A Straightforward Guide to Installation
One of the best features of this module is its ease of installation. For most 2007-2013 Sierra 1500 models, you can have this swapped out in your own driveway in under 30 minutes. No specialized tools are required.
- Safety First: Always disconnect the negative terminal on your truck’s battery before starting any electrical work.
- Locate the TCM: On your Sierra, the TCM is typically mounted right next to the battery in the engine compartment. It’s a silver box with several large electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses from the old module. Press the release tabs firmly to avoid damaging them. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely plug the electrical connectors back in. You’ll hear a ‘click’ when they are properly seated.
- Reconnect and Finalize: Reconnect the negative battery terminal. Start the truck and allow it to idle for a few minutes. If you have a basic OBD2 scanner, it’s good practice to clear any stored fault codes. Take the truck for a test drive to confirm smooth shifting.
Will This Fit My Truck?
This T42 Transmission Control 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. While it is the correct part for the 2007-2013 Sierra 1500 TCM, it also fits many other models. Please verify your part number (24240400) or check the list below for confirmed compatibility.
- GMC Sierra 1500 Pickup (2007-2013): Located next to the battery. (For 2007, fits new body style with smooth door skin).
- Chevrolet Silverado 1500 Pickup (2007-2013): Located next to the battery. (For 2007, fits new body style with smooth door skin).
- GMC/Chevrolet Vans (Savana/Express 1500/2500/3500, 2006-2014): Found in the RH engine compartment.
- GMC/Chevrolet SUVs (Yukon/Tahoe/Suburban/Avalanche, 2007-2009): Located next to the battery.
- Chevrolet Colorado / GMC Canyon (2008-2012): Found in the RH rear engine compartment.
- Hummer H3 (2008-2010): Located in the RH rear engine compartment.
- …and many other Buick, Cadillac, Pontiac, and Saturn models.
Frequently Asked Questions
Do I need to take my truck to the dealer for programming after installation?
No. This is the key benefit of our service. We program the TCM to your vehicle’s VIN before shipping. This makes it a true plug-and-play part, saving you the time, cost, and hassle of a dealership visit.
Is this part difficult to install for a DIYer?
Not at all. For the Sierra 1500, it’s one of the easier electronic components to replace. It’s located right next to the battery and requires only basic hand tools. Most customers complete the installation in under 30 minutes.
What if I install this and my problem doesn’t go away?
While this module fixes the vast majority of common shifting issues, transmissions are complex. If the problem persists, it may indicate a mechanical issue within the transmission itself (like a faulty solenoid or clutch pack) that the TCM was correctly identifying. We recommend a full diagnostic scan to check for solenoid-specific codes.
Is there a core charge? Do I need to send my old part back?
No, there is no core charge on this part. You can keep your old module or dispose of it responsibly without any obligation to return it to us.
What happens if I provide the wrong VIN?
Providing the correct VIN is critical for proper function. Please double-check the VIN from your driver’s side door jamb or dashboard plate before ordering. An incorrect VIN will lead to communication errors and improper shifting. If you have any doubts, please contact our support team for assistance.