2003 GMC Envoy Owner's Manual - Page 206

qadi0 with Six-Disc CD AUTO VOL (Automatic Volume): Your system has a feature called automatic volume. With this feature, your audio system adjusts automatically to make up for road and wind noise as you drive. Set the volume at the desired level. Press this button to select MIN, MED or MAX. Each higher setting will allow for more volume compensation at faster vehicle speeds. Then, as you drive, automatic volume increases the volume, as necessary, to overcome noise at any speed. The volume level should always sound the same to you as you drive. If you don't want to use automatic volume, select OFF. RCL (Recall): Push this knob to switch the display between the time and the radio station frequency. Push this knob with the ignition off to display the time. OP Playing the Radio PWR (Power): Push this knob to turn the system and off. VOL (Volume): Turn the knob to increase or to decrease volume. To change the default on the display, push the knob until you see the display you want, then hold the knob for two seconds. The radio will produce one beep and selected display will now be the default. 3-8 1