Restore Flawless Shifting to Your Heavy-Duty Truck
Your 2015-2016 GMC Sierra 3500 is a powerhouse, built for tough jobs and heavy loads. The 6-speed automatic transmission (RPO code MW7) is the heart of that capability, and its brain is the Transmission Control Module (TCM). When the TCM begins to fail, it can sideline your truck with confusing and frustrating symptoms, from harsh, unpredictable shifts to a complete loss of power. This direct-replacement TCM, part number 24272004, is the definitive solution. It arrives at your door fully programmed with the latest GM software, tailored specifically to your truck’s Vehicle Identification Number (VIN). This eliminates the need for expensive dealership visits or specialized scan tools, making the repair straightforward and getting you back to work faster.
Signs Your Transmission Control Module is Failing
- ✔ Sudden, harsh, or delayed gear engagement.
- ✔ The transmission feels like it’s slipping or hunting for gears.
- ✔ Your truck gets stuck in one gear, often referred to as “limp mode.”
- ✔ An illuminated Check Engine Light with transmission-related Diagnostic Trouble Codes (DTCs) such as P0700, P0751, or U0101 (Lost Communication with TCM).
- ✔ Inaccurate or erratic speedometer readings.
- ✔ Decreased fuel economy due to inefficient shifting.
Step-by-Step Guide to Replacing Your 2015-2016 Sierra 3500 TCM
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts.
- Locate the TCM: On the 2015-2016 Sierra HD trucks, the TCM is typically mounted on the driver’s side of the fan shroud in the engine bay. It’s a silver box with large electrical connectors.
- Disconnect the Old Module: Carefully release the locking tabs on the main electrical harnesses and pull them straight out from the module. Avoid pulling on the wires themselves.
- Remove the Module: Unbolt the few fasteners holding the TCM to its mounting bracket on the fan shroud. Keep the hardware in a safe place.
- Install the New TCM: Mount your new, pre-programmed module onto the bracket and secure it with the original hardware.
- Reconnect and Secure: Firmly press the electrical connectors into the new TCM until they click into place, ensuring a solid connection. Reconnect the negative battery terminal.
- Final Check: Start the engine and allow it to idle for a minute. Cycle through the gears (Park, Reverse, Neutral, Drive) to ensure proper engagement. A short test drive will confirm that shifting performance is restored.
A Mechanic’s Field Tale: The Case of the Hesitant Hauler
A customer brought in his ’16 Sierra 3500, complaining it felt gutless and was slamming into gear, especially when towing his fifth-wheel trailer. He was worried his Allison transmission was shot. After pulling the codes, we saw a classic U0101—the TCM wasn’t talking properly to the rest of the truck. Instead of a costly transmission rebuild, we identified the faulty module. With a pre-programmed unit like this one, the swap took less than 30 minutes in the bay. The customer called later that day, amazed. He said his truck drove better than it had in years, with crisp, clean shifts even with his trailer hitched up. It’s a perfect example of how the right electronic part can completely transform a vehicle’s performance and save thousands in unnecessary mechanical work.
Perfect Match for These Models
This module is a direct fit for a wide range of GM trucks and SUVs. While this listing is for the Sierra Denali 3500, it is also compatible with the following vehicles equipped with the specified options:
- 2016 CAMARO (Transmission Control)
- 2016 CTS (Transmission, ID 24276411)
- 2015-2017 ESCALADE & ESCALADE ESV (8 speed, opt M5U)
- 2015-2016 SIERRA 1500 PICKUP (8 speed, opt M5U)
- 2015-2016 SIERRA 2500 & 3500 PICKUP (6 speed, opt MW7)
- 2015-2016 SIERRA DENALI 1500, 2500, & 3500
- 2015-2016 SILVERADO 1500 PICKUP (8 speed, opt M5U)
- 2015-2016 SILVERADO 2500 & 3500 PICKUP (6 speed, opt MW7)
- 2015-2016 YUKON & YUKON XL 1500 (8 speed, opt M5U)
Note: Always verify your part number (24272004 or 24276411) and vehicle options to ensure proper fitment.
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). You can typically add it as a note to the seller during checkout or send it to us in a direct message referencing your order number. We cannot ship the module until we receive your VIN.
Is any additional programming or a “relearn” procedure required after installation?
No. Because we program the module with the latest GM software using your specific VIN, it is a true plug-and-play solution. No further dealer programming or complex relearn procedures are necessary. Just install it and drive.
Where is the TCM located on my 2015 Sierra 3500?
The Transmission Control Module is located in the engine bay, mounted directly to the driver’s side of the radiator fan shroud. It’s a rectangular metal box with large wiring harnesses connected to it.
My original part number is 24276411. Will this module work?
Yes, this module, 24272004, is a fully compatible and interchangeable part for 24276411. It will function identically once programmed to your vehicle’s VIN.
What happens if I install it without providing a VIN?
The module will not function correctly. It may cause shifting problems, set error codes, or prevent the vehicle from starting. The programming is essential as it configures the module for your truck’s specific engine, axle ratio, and other critical systems.