An alert will come up on the screen of my controller warning of lost connection with brakes within about a minute of pulling the plug. You also have the option of audible alarm. I don't have hyd disks, but the controller will work with electric over hyd disks, and I presume would give the same connection lost warning.
I think if you pay attention to the condition of your brakes, connectors, and stuff, and drive extra carefully and brake way early when towing, the likelyhood of a sudden failure causing an accident would be pretty small.
Dodge Ram dually laramie 4x4 w/jake, B&W, Brakesmart.
Kit Patio Hauler 394F toyhauler 5th wheel
Camo 680 Rincon, Green 500 Foreman, Blk twincam Roadking