Fixes the 2024–2026 GM Silverado, Sierra, and Denali “Service Trailer Brakes” dashboard warning. This plug-and-play inline diode resolves the compatibility issue between GM’s factory integrated brake controller and electric drum brake trailers. Install takes minutes — cut the blue wire, crimp the module inline, done.
2024–26
GM Trucks
PLUG
& Play
7075
Part #
DOT
Compliant
The Problem
Why Your GM Truck Disables Trailer Brakes
GM’s 2024–2026 factory integrated brake controller sends a diagnostic signal down the blue (brake) wire. When it doesn’t get the response it expects from electric drum brake systems, it triggers a fault — displaying “Service Trailer Brakes” on your dash and disabling braking. This module intercepts that signal and allows normal operation.
Questions about fitment?
Feel free to reach out to us or start a live chat in the bottom right corner for assistance.
Specifications
Technical Details
Compatible Vehicles
2024–2026 GM Silverado, Sierra, Denali, and other models with factory integrated brake controllers
Brake System
Electric Drum Brake
Installation
Inline on the blue (brake controller) wire, ~10" from the actuator
Type
2-wire inline diode module
Effect on Other Vehicles
None — does not affect non-GM tow vehicles
Part Number
381-7075
Common Questions
Before You Buy
Does this work with non-Hydrastar actuators?+
Yes. The 381-7075 works with any brand of electric drum brake system.
How do I install it?+
Cut the blue wire approximately 10" from the actuator. Crimp the module inline — wires are labeled for direction. Heat shrink the connections. Arrow on the diode points toward the actuator.
Will this void my GM warranty?+
No. This module is installed on the trailer side, not the vehicle side.
My dealer told me about this — is this the right part?+
Yes. GM dealerships are actively referring customers to Hydrastar for this fix. Part #381-7075 for electric drum brake trailers.
![2024 - 2025 GM Controller Adapter Module [381-7075] for Electric Drum Brakes - Hydrastar](http://hydrastarusa.com/cdn/shop/files/Diode_6424bf7a-d7d0-4d2d-b9fc-29a379bbc508_525x700.png?v=1755792045)
![2024 - 2025 GM Controller Adapter Module [381-7074] [*381-7075] - Hydrastar](http://hydrastarusa.com/cdn/shop/files/wiring_inst_679x450.png?v=1755791953)