This Custom Fit Interface Harness is designed for use with the Scosche S3-1 interface. It allows you to replace your Factory OEM stereo while retaining the Factory Timed Accessory output as well as retaining Factory Digital Premium audio systems. This combination will also allow you to retain Factory steering wheel controls if vehicle is equipped. It keeps Factory CAN Bus data system intact for diagnostic purposes and provides data-controlled +12V Accessory output for aftermarket stereo. It also retains factory premium audio systems in a 2CH format. In addition, it provides data-controlled parking brake trigger, reverse trigger, vehicle speed sense and illumination output.