Embodiments of the invention provide a device and method for controlling sway of a trailer utilizing a global positioning system (GPS) device to detect a speed of a vehicle, a rate gyro to detect a sway angle of the vehicle, and a controller coupled to the GPS device and the rate gyro. The GPS and the rate gyro provide the speed and the sway angle to the controller and the controller outputs a brake command if either a first condition is satisfied or a second condition is satisfied.