Restore Peak Performance to Your GM HD Truck
There’s nothing more frustrating than when your powerful Sierra or Silverado HD workhorse starts acting up. The legendary Allison transmission is known for its durability, but the electronic brain controlling it—the Transmission Control Module (TCM)—can be a common point of failure. If you’re dealing with harsh shifting, getting stuck in gear, or a transmission warning light that won’t go away, you’ve come to the right place. As a technician with over two decades of experience, I’ve seen firsthand how a faulty TCM can sideline an otherwise perfect truck. This isn’t just a part; it’s a direct solution to get your vehicle’s performance and reliability back to factory standards.
This module, part number 29537441, is a direct-fit replacement for your original unit. The best part? We handle the programming for you. Simply provide your vehicle’s VIN during checkout, and we will flash the module with the latest GM software updates specific to your truck. This means no expensive trips to the dealership, no waiting for appointments, and no need for specialized programming tools. It arrives at your door ready to install, saving you significant time and money.
From the Diagnostic Bay: The Intermittent Limp Mode Nightmare
I remember a 2004 Silverado 2500HD that came into my shop with a complaint that stumped two other mechanics. The owner said it would randomly go into limp mode (stuck in 3rd gear) but would be fine after restarting the truck. There were no hard codes, only a history code for U0100 (Lost Communication with ECM/PCM). After checking all the wiring and connectors, I suspected the TCM itself was failing internally, but only when it got hot. We swapped in one of our pre-programmed modules, and the problem was solved instantly. The customer was back on the road in under an hour, without the weeks of diagnostic guesswork he’d endured before. It’s a classic example of how heat and vibration can cause hairline cracks in the TCM’s circuit board, leading to these frustrating, intermittent issues.
Is Your Allison Transmission Acting Up?
A failing TCM can manifest in several ways. If your truck is showing any of these signs, a faulty module is a very likely culprit:
- ✔ Erratic or harsh shifting between gears.
- ✔ The truck getting stuck in one gear, often referred to as “limp mode.”
- ✔ A delay in engagement when shifting from Park to Drive or Reverse.
- ✔ Illumination of the Check Engine Light or a transmission-specific warning light.
- ✔ Diagnostic Trouble Codes (DTCs) stored in the system, such as P0700, P0751, or U0107.
- ✔ Poor fuel economy due to inefficient shift patterns.
A Straightforward Guide to Installation
Replacing the TCM on these trucks is a job most DIYers can handle with basic tools. Our pre-programmed module makes the process even simpler.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the TCM: On most 2001-2005 GM HD trucks, the TCM is mounted on the driver’s side of the fan shroud in the engine bay.
- Disconnect the Wiring: Carefully unclip and remove the large electrical connectors from the old module. Inspect them for any corrosion or damage.
- Unbolt the Old Module: Remove the bolts or screws securing the TCM to its mounting bracket.
- Install the New TCM: Mount your new, pre-programmed TCM in place and secure it with the original hardware.
- Reconnect Everything: Plug the electrical connectors firmly into the new module. Reconnect the negative battery terminal.
- Final Check: Start the vehicle and check for proper gear engagement and smooth shifting. Your check engine light should be off.
Will This Fit My Truck?
This 2001-2005 Sierra 2500 TCM is guaranteed to be compatible with the following vehicles equipped with the 5-speed Allison automatic transmission (RPO Code M74). It is a direct replacement for multiple service numbers, including 15768288, 15163072, 29537441, and more.
- 2001-2005 GMC Sierra 2500 HD Pickup (with 5-speed Allison AT)
- 2001-2005 GMC Sierra 3500 Pickup (with 5-speed Allison AT)
- 2001-2005 Chevrolet Silverado 2500 HD Pickup (with 5-speed Allison AT)
- 2001-2005 Chevrolet Silverado 3500 Pickup (with 5-speed Allison AT)
Frequently Asked Questions
Frequently Asked Questions
Do I need to do any programming myself?
No. We program the module to your truck’s specific VIN before shipping it. It arrives ready for installation with no additional programming required.
How do I provide my VIN?
Simply enter your 17-digit Vehicle Identification Number (VIN) in the designated box during the checkout process or send it to us in a message after your purchase.
Is this a new or a used part?
This is a high-quality, inspected, and tested used OEM part that has been professionally programmed with the latest software for your vehicle, ensuring reliable performance.
Where is the TCM located on my 2003 Silverado 2500HD?
The location is consistent for this model range. You will find the Transmission Control Module mounted on the driver’s side of the plastic fan shroud, right behind the radiator.
Will this fix a P0700 trouble code?
A P0700 code simply means the TCM has requested the check engine light to turn on because it has stored a specific transmission-related fault. While this module often resolves the root cause, it’s always best to have the vehicle scanned to see what other codes are present alongside the P0700.
What if I have a different service number on my old part?
This module is a compatible replacement for a wide range of service numbers, including 15768288, 15071240, 15163072, and 29537441 among others. As long as your vehicle is listed in our fitment chart, this part will work correctly.