The radio is used to adjust the vehicle's chime level. To change the volume level of the chime, press and hold pushbutton 6 or the sixth FAV pushbutton with the ignition on and the radio power off. The volume level will change from the normal level to loud, and Loud will appear on the radio display. To change back to the normal setting, press and hold pushbutton 6 or the sixth FAV pushbutton again. The volume level will change from the loud level to normal, and Normal will appear on the radio display. Removing the radio and not replacing it with a factory radio or chime module will disable vehicle chimes.