GM Controller Adapter Modules

If you're seeing the "Service Trailer Brake System" warning on your 2024-2026 GM truck while towing a Hydrastar EOH-equipped trailer, you need a Hydrastar Controller Adapter Module (CAM). This issue affects Chevrolet Silverado, GMC Sierra, Cadillac Escalade, Chevrolet Tahoe, Chevrolet Suburban, GMC Yukon, Chevrolet Colorado, GMC Canyon, and GMC Hummer EV equipped with the integrated trailer brake controller.

The Hydrastar CAM is a plug-and-play inline solution that resolves the compatibility issue between newer GM truck integrated trailer brake controllers and electric over hydraulic (EOH) actuator systems. Installation is simple — the CAM connects between your truck's 7-way connector and the trailer's wiring harness, eliminating the warning message and restoring full trailer brake functionality.

Hydrastar offers different CAM modules for different brake configurations:

381-7073 for Hydrastar EOH systems on Ford trucks (also resolves connectivity drops after dealer flashes)
381-7074 for 2024-2026 GM trucks with electric over hydraulic disc or drum brake systems
381-7075 for 2024-2026 GM trucks with electric drum brake systems
Xtra Capacity Retro Kit for upgrading older Hydrastar systems

Each CAM module is made in the USA with weatherproof construction and proven reliability. This is not a Hydrastar product issue, it is a GM compatibility issue that Hydrastar developed a solution for, and we have helped thousands of GM truck owners get back on the road with full trailer brake functionality.