Does 2012 Scion xB has auto headlight sensor

Hello, sounds more like it has an indicator to let you know the lights are on, not so much that there is a sensor. An "auto lamp" sensor would be present to automatically turn lights on when the outside light drops below a certain threshold. This is different than the beeping. If you have further questions, see a local dealership or a repair facility, or have a look at your owners manual.