Automatic Volume Control
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
With automatic volume, the audio system adjusts automatically to make up for road and wind noise by increasing the volume as vehicle speed increases. On first design Bose amplifiers (class 2) the system uses a noise compensation microphone to monitor cabin noise and increase volume as needed, press the AUTO VOL button until AVOL ON appears on the display, to turn off press AUTO VOL button until AVOL OFF is displayed. On second design Bose amplifiers (non-class 2) and base radios the radio uses a vehicle speed signal, received via class 2 message to adjust volume based on speed, press the AUTO VOL button to select LOW, MEDIUM, or HIGH. To turn AUTO VOL off, press until AVOL OFF is displayed.