Restore Flawless Shifting to Your GM Truck
Is your 2007-2013 GMC Sierra 1500 suffering from harsh, delayed, or unpredictable shifting? A failing Transmission Control Module (TCM) is one of the most common culprits behind these frustrating and potentially damaging issues. As the electronic brain of your automatic transmission, the TCM governs every gear change, torque converter clutch engagement, and line pressure adjustment. When it fails, your truck’s performance and reliability are compromised. This OEM-quality T42 TCM, part number 24239926, is the definitive solution, arriving pre-programmed to your truck’s specific VIN for a true plug-and-play installation.
A Technician’s Notebook: The Intermittent Ghost
I once had a 2011 Sierra 1500 in my bay that was driving the owner crazy. The complaint was intermittent harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode), but only after driving for 30+ minutes. There were no consistent solenoid codes, just a generic P0700 (Transmission Control System Malfunction). After checking the wiring and fluid, everything seemed fine. The root cause? The original TCM. Over thousands of heat cycles in the engine bay, microscopic cracks had formed on the circuit board, causing intermittent connection loss when the module got hot. Replacing it with a VIN-programmed unit like this one solved the problem instantly. These failures are common, and a direct replacement is the most reliable fix.
Is Your Sierra Exhibiting These Telltale Signs?
A faulty TCM can manifest in several ways. If you’re experiencing any of the following, it’s time to consider a replacement:
- âś” Unusually harsh, banging, or erratic gear shifts.
- âś” The transmission feels like it’s slipping between gears.
- âś” Your truck is stuck in “limp mode,” usually in 2nd or 3rd gear.
- âś” The Check Engine Light is on with codes like P0700, P0750-P0758 (solenoid circuits), or other transmission-related DTCs.
- âś” Delayed engagement when shifting from Park to Drive or Reverse.
- âś” A sudden, unexplained drop in fuel economy.
Get Your Truck Shifting Smoothly: A 30-Minute Fix
This isn’t a job that requires a full day or specialized tools. Because this module comes pre-programmed, you can get your truck back to perfect working order right in your own driveway.
- Safety First: Always disconnect the negative terminal from your truck’s battery before starting any electrical work.
- Locate the Module: On most 2007-2013 Sierra 1500 models, the TCM is conveniently located in the engine compartment, right next to the battery.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Bolt the new, VIN-programmed module into place and securely reconnect the electrical harnesses. You should hear a click as they lock in.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s good practice to use a basic OBD2 scan tool to clear any stored fault codes from the vehicle’s memory.
Verified Fitment for Your General Motors Vehicle
This T42 Transmission Control Module is a direct replacement for a wide range of GM trucks, vans, and SUVs equipped with 4-speed automatic transmissions (4L60E, 4L65E, 4L70E). It interchanges with part numbers 24252114, 24234503, 24239926, and more. While this page focuses on the Sierra 1500 Transmission Control Module, it also fits:
- âś” Chevrolet Silverado, Tahoe, Suburban, Avalanche, Express Van, Colorado
- âś” GMC Yukon, Savana Van, Canyon, Envoy
- âś” Cadillac DTS, Escalade
- âś” Hummer H3
- …and many other GM models from 2006-2014. Please verify the part number or use our fitment tool to ensure compatibility.
Frequently Asked Questions
Do I need to take my truck to the dealership for programming?
No. This is the biggest benefit. We program the module to your vehicle’s VIN before shipping it. It arrives ready for installation, saving you time and money on dealer fees.
Is this a difficult part to install for a DIYer?
Not at all. For most Sierra and Silverado trucks, the TCM is located next to the battery and is held in by a few bolts. With basic hand tools, most people can complete the swap in under 30 minutes.
What is a core charge? Do I need to send my old part back?
There is no core charge for this part. You can keep your old module or dispose of it without any hassle or need to return it to us.
Will this fix a P0700 check engine light code?
If the P0700 code is being triggered by an internal failure of the TCM, then yes, replacing it will resolve the issue. P0700 is a general code indicating a fault in the transmission control system, which often points directly to a bad module.
What kind of warranty is included?
This module is backed by our one-year, hassle-free warranty, giving you peace of mind and confidence in your repair.