go to a lexus dealer and ask them to go threw the functions of the stereo with you. do not disconnect the battery terminal because you stereo may lock up on you and you will need a code to unlock it so go to the dealer im sure its just a button you moved or touched.and they can't charge you to show you the functions of the stereo.hope this helps.play with the buttons and learn you can't he rt nothing and see if you have the manuel in the glove box and do some reading.