Restore Safe and Reliable Towing to Your GM Truck
Seeing the dreaded “Service Trailer Brake System” message on your dash? Experiencing intermittent or non-existent trailer braking? Don’t risk your safety or the safety of your valuable cargo. A faulty Trailer Brake Control Module (TBCM) is a common issue on these hard-working trucks, but we have the definitive, hassle-free solution. This module is the electronic brain that ensures your truck and trailer brakes work in perfect harmony, and restoring its function is critical for safe hauling.
Common Symptoms & Your Direct-Fit Solution
If you’re dealing with any of the following issues, a failing TBCM is the likely culprit:
- Constant “Service Trailer Brake System” warning on the Driver Information Center (DIC)
- “Trailer Connected / Disconnected” messages cycling randomly
- No output to the trailer brakes when the pedal or manual slider is used
- Diagnostic Trouble Codes (DTCs) related to lost communication with the TBCM
This GM Trailer Brake Control Module 25907533 is your direct-fit, plug-and-play answer. Unlike a generic part from a salvage yard, we professionally program each module to your truck’s specific Vehicle Identification Number (VIN) before it ships. This crucial step ensures flawless communication with your truck’s other computers, eliminating error messages and restoring full functionality without a costly and time-consuming trip to the dealership.
Features & Tangible Benefits
- ✔ VIN-Programmed for Your Truck: We flash the module with the latest GM software using your VIN. This means it arrives ready for a true plug-and-play installation, saving you hundreds in dealer programming fees.
- ✔ Restores Full Braking Control: Regain precise, synchronized control over your trailer’s brakes for safer stops, reduced sway, and confident driving on hills and in traffic.
- ✔ Eliminates Annoying Dash Warnings: Clear the persistent “Service Trailer Brake System” message for good and enjoy a clean, error-free dash display.
- ✔ Guaranteed Compatibility: This module is a direct replacement for part numbers 20850923, 25854535, 25788981, and 25907533, ensuring a perfect fit and correct electronic communication.
- ✔ Purchase with Confidence: This unit is backed by our one-year replacement warranty.
Expert Insight: The Critical Role of VIN Programming
As a veteran tech, I’ve seen countless truck owners buy a used TBCM from a junkyard, hoping for a cheap fix. They install it, and the error message remains. Why? Because on modern trucks, modules are not interchangeable. Each module is coded to the original truck’s specific options and features. Our VIN programming service isn’t just a convenience—it’s the essential step that makes the part work correctly. We ensure your new GM Trailer Brake Control Module 25907533 speaks the exact same digital language as your truck, guaranteeing a successful repair the first time.
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, simply send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot ship your part until we receive this information, as the programming is a required step.
Is this a simple plug-and-play installation?
Yes. Because we pre-program the module to your VIN, the physical installation is straightforward. The module is typically located on the driver-side frame rail, near the rear axle. Simply disconnect the battery, unplug the old module, unbolt it, and install the new one. No further programming is required.
Will this fix the “Service Trailer Brake System” message?
In the vast majority of cases, yes. This message is the primary indicator that the original GM Trailer Brake Control Module 25907533 has failed. Replacing it with our correctly programmed unit is the standard and effective repair.
Where is this module located on my truck?
You will find the Trailer Brake Control Module mounted to the inside of the frame rail on the driver’s side (LH side), typically just in front of the rear axle. It’s a black box with a single large electrical connector.
What happens if I install a module that isn’t programmed?
An unprogrammed or incorrectly programmed module will not communicate with your truck’s Body Control Module (BCM) and other systems. This means it will not function, and the error messages on your dash will persist. Our VIN-specific programming solves this problem completely.
Is this compatible with part number 20850923?
Yes, this module is a direct, compatible replacement for several part numbers, including 20850923, 25854535, 25788981, and 25907533. It will function identically once programmed for your vehicle.