2001 GMC Sierra 1500 Pickup Owner's Manual - Page 212

AM-FM Stereo with Compact Disc Player and Automatic Tone Control (If Equipped) SCV: Your system has a feature called Speed-Compensated Volume (SCV). With SCV, your audio system adjusts automatically to make up for road and wind noise as you drive. Set the volume at the desired level. Turn the control ring behind the upper knob clockwise to adjust the SCV. Then, as you drive, SCV automatically increases the volume, as necessary, to overcome noise at any particular speed. The volume level should always sound the same to you as you drive. If you don't want to use SCV, turn the control all the way down. Each notch on the control ring allows for more volume compensation at faster vehicle speeds. Finding a Station Playing the Radio PWR-VOL: Press this knob to turn the system on and off. To increase volume, turn this knob clockwise. Turn it counterclockwise to decrease volume. The knob is capable of rotating continuously. RECALL: Display the time with the ignition off by pressing this button. When the radio is playing, press this button to recall the station frequency. AM-FM: Press this button to switch between AM, FM1 and FM2. The display will show your selection. TUNE: Press this knob lightly so it extends. Turn it to choose radio stations. Push the knob back into its stored position when you're not using it. SEEK: Press the right arrow to tune to the next higher station and the left arrow to tune to the next lower station and stay there. The sound will mute while seeking. 3-25