For 1990-2009 cars

The radio may be used to adjust the vehicle's chime level. If the radio can be used to change the volume level of the chime, press and hold the sixth FAV softkey with the ignition on and the radio power off. The volume level changes between Normal and Loud. The selected volume level appears on the radio display.

Removing the radio and not replacing it with a factory radio or chime module will disable vehicle chimes.