Restore Safe Towing with a Plug-and-Play Solution
Is your Silverado or Sierra displaying a persistent “Service Trailer Brake System” message on the dash? Are you losing confidence in your truck’s ability to safely stop a heavy load? A faulty Trailer Brake Control Module (TBCM) is the most common cause of these issues, creating a serious safety hazard. A trip to the dealership for a replacement and mandatory programming can be incredibly costly and time-consuming. We offer the definitive, direct-fit solution to get you back on the road with full confidence and control.
Common Symptoms & Your Direct-Fit Solution
If you’re experiencing any of the following, a failing TBCM is the likely culprit:
- “Service Trailer Brake System” Warning Light
- “Trailer Connected / Disconnected” Messages Cycling Randomly
- Trailer Brakes Not Engaging or Engaging Erratically
- Diagnostic Trouble Codes (DTCs) such as C151C, C151D, or U0100
This isn’t just a replacement part; it’s a complete, ready-to-install solution. Our expert technicians flash this genuine GM Trailer Brake Control Module 20850923 with the latest official GM software, specifically coded to your truck’s unique Vehicle Identification Number (VIN). This critical programming step ensures perfect communication with your truck’s other systems, restoring original performance and clearing frustrating dash warnings.
Features & Tangible Benefits
- ✔ VIN-Programmed for Your Truck: Your module arrives ready for installation right out of the box. This completely eliminates the need for an expensive trip to the dealership for programming, saving you time and hundreds of dollars.
- ✔ Loaded with Updated GM Software: We flash the unit with the newest software updates from General Motors, ensuring optimal performance, enhanced reliability, and fixes for any known factory bugs.
- ✔ Guaranteed Direct-Fit Replacement: This module is a direct replacement for part numbers 20850923, 25854535, 25788981, and 25907533, ensuring a perfect fit and seamless integration on your 2007-2009 GM truck.
- ✔ Restores Critical Towing Safety: Regain full, reliable, and predictable control over your trailer’s brakes. Haul your equipment, RV, or boat with the peace of mind that comes from a fully functional braking system.
- ✔ Backed by Our Warranty: This unit is backed by our one-year replacement warranty.
From the Technician’s Bench
“As a career tech, I’ve seen countless truck owners replace a TBCM themselves, only to find it still doesn’t work because it wasn’t programmed. The dealership then charges a separate, hefty fee for a 15-minute software flash. Our process removes that expensive and frustrating extra step. We handle the complex programming so you can handle the simple installation, getting your truck back to work faster and for less money. This is the way this repair should be done.”
Don’t compromise on the safety of your truck, your trailer, and your cargo. This pre-programmed GM Trailer Brake Control Module 20850923 is the most reliable and cost-effective way to permanently fix your trailer brake issues and restore the full towing capability of your Silverado or Sierra.
Frequently Asked Questions
How does the VIN programming process work?
It’s simple. After you place your order, you will need to provide us with your vehicle’s 17-digit VIN. Our technicians then use this VIN to flash the module with the correct software and calibration files for your specific truck before we ship it to you.
Is this part difficult to install?
For most individuals with basic mechanical skills, this is a straightforward installation. The module is located on the driver’s side frame rail, towards the rear of the truck. It typically involves removing a few bolts and disconnecting the electrical harness. Since our module is pre-programmed, no further steps are needed after installation.
Will this clear the ‘Service Trailer Brake System’ message?
Yes. In the vast majority of cases, a faulty or failing TBCM is the direct cause of this warning. Installing this correctly programmed module is the specific repair designed to resolve that issue and extinguish the warning light.
How do I ensure this is the right part for my truck?
This module fits the models listed in the description. The most important step is providing your VIN. We use your VIN to verify exact fitment and apply the correct programming, which virtually eliminates any chance of incompatibility.
Do I need any special tools for installation?
No special diagnostic tools are required. The installation can typically be completed with a basic socket set to remove the mounting bolts. Because the GM Trailer Brake Control Module 20850923 arrives pre-programmed, there is no need for a dealer scan tool.