Stop Guessing and Start Towing Safely Again
Seeing the ‘Service Trailer Brake System’ message on your dash is more than an annoyance—it’s a critical safety warning. When you’re hauling a heavy load, you need absolute confidence that your trailer brakes will respond instantly and correctly. This Trailer Brake Control Module (TBCM) is the definitive solution, arriving at your door fully programmed to your truck’s specific VIN. Forget the expensive dealership visit and the hassle of programming tools; this is the direct-fit, plug-and-play fix that gets you back on the road with peace of mind.
Common Symptoms & Your Direct-Fit Solution
If you’re experiencing any of the issues below, a failing TBCM is the most likely culprit. Located on the frame rail, these modules are exposed to the elements, leading to internal corrosion and eventual failure. This replacement part directly addresses these problems:
- Persistent ‘Service Trailer Brake System’ warning on the driver information center (DIC).
- ‘Trailer Connected’ or ‘Trailer Disconnected’ messages cycling randomly.
- No output or weak output from the trailer brakes, even with the gain set to maximum.
- The manual trailer brake lever is unresponsive.
- Diagnostic Trouble Codes (DTCs) such as C151C, C151D, or U0415 stored in the system.
This programmed trailer brake control module 20964299 is engineered to be the final fix for these exact issues, restoring the full, safe functionality your GM truck was built for.
Features & Tangible Benefits
- ✔ Pre-Programmed to Your VIN: We flash the module with the latest GM software using your vehicle’s VIN before shipping. This means no extra costs or trips to the dealer for programming.
- ✔ Plug-and-Play Installation: Simply unbolt the old module from the frame rail, disconnect the harness, and install the new one. It’s a true bolt-in replacement.
- ✔ Restored Towing Safety: Regain precise, reliable control over your trailer’s brakes for safer stops and better control, especially on steep grades or in emergency situations.
- ✔ Eliminate Annoying Dash Warnings: Clear the persistent ‘Service Trailer Brake System’ message for good and enjoy a clean, warning-free dash.
- ✔ OEM-Level Performance: This module meets or exceeds original equipment specifications for a seamless integration with your truck’s existing systems. Compatible with part numbers 20964299 and 20850923.
- ✔ Guaranteed Protection: This unit is backed by our one-year replacement warranty.
An Expert’s Take: Why This Module Matters
As a technician, I’ve seen firsthand what happens when a TBCM fails. The most dangerous scenario is descending a long, steep grade with a heavy trailer. You rely on that module to apply the trailer brakes smoothly, preventing the trailer from pushing the truck and causing a loss of control. The original modules are mounted in a vulnerable spot on the frame, where they’re constantly blasted with road salt, water, and debris. This leads to water intrusion and circuit board failure. Installing a fresh, correctly programmed module isn’t just about clearing a light on the dash; it’s one of the most important safety repairs you can make for your heavy-duty truck.
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, you will need to send us a message with your vehicle’s 17-digit VIN. We cannot ship your order until we receive this information, as the programming is a critical step to ensure compatibility.
Is this a difficult part to install myself?
For most DIY mechanics, this is a straightforward installation. The module is typically located on the driver’s side frame rail. It involves removing a few bolts and a single electrical connector. Since our module is pre-programmed, no special tools are required for the electronic setup. However, the original bolts may be rusted, so having some penetrating oil on hand is a good idea.
Will this fit my 2012 model truck?
This specific module is for the 2013-2014 model years of the Sierra, Silverado, Suburban 2500, and Yukon XL 2500. Please verify the part number (20964299 or 20850923) matches what is required for your vehicle. Using the wrong module can cause communication errors with other systems on the truck.
What if I install this and the problem doesn’t go away?
While this programmed trailer brake control module 20964299 is the solution in over 95% of cases, the ‘Service Trailer Brake System’ message can sometimes be caused by a wiring issue between the module and the 7-pin trailer connector, or a problem with the trailer itself. We recommend inspecting the wiring harness for any visible damage or corrosion before and during installation.
Is this a genuine GM part?
This is a high-quality replacement part that is programmed using official GM software updates to ensure perfect functionality and communication with your vehicle’s computer systems, just like the original component.