Volvo radio units have few hidden menus that will help you with diagnostics and let you change advanced settings. Turn the radio on by pressing and holding volume knob. After few seconds advanced menu will appear. Here you can enable alternative frequencies, regional lock, change language, automatic sound correction, and noice correction. Press and hold AUTO button and turn the radio on. Wait few seconds for the diagnostic mode. Press and hold SOURCE knob and turn the radio on. After few seconds you’ll see advanced audio equalizer for front and back speakers. Press and hold REWIND button and turn the radio on. Wait few seconds for the advanced diagnostic mode. Here you can check EEPROM version and perform display test. Press and hold PREVIOUS TRACK button and turn the radio on. Here you can test antenna diversity and set various noise levels of the radio antenna.