2003 Cadillac CTS Owner's Manual - Page 249

Audio Steering Wheel Controls Some audio controls can be adjusted at the steering wheel. They include the following: Volume: Turning the knob increases and decreases volume. (Mute): Press this button to silence the system. Press it again to turn on the sound. If your vehicle has the Navigation system, this button does not have a mute function. See "Reconfigurable Steering Wheel Controls (SWC)" in the Index for more information on this feature. (Band/Source): Press this button to select AM, FM1, FM2 or a source, either radio, cassette tape or CD. The cassette or CD must be loaded to play. Available loaded sources are shown on the display as a tape or a CD symbol. (For vehicles with the six-disc changer radio - If none of the audio sources are loaded, and this button is pressed, NO SOURCE LOADED will appear on the display.) 3-28