2007 Cadillac STS Owner's Manual - Page 310

Audio Steering Wheel Controls Some audio controls can be adjusted at the steering wheel. They include the following: Right Side Controls For STS-V Left Side Controls For Both STS and STS-V Right Side Controls For STS 0 (Mute): Press this button to silence the system. Press this button again, or any other radio button, to turn the sound on. SRCE (Source): Press this button to switch between FM1, FM2, AM, or XM1 or XM2 (if equipped) radio or CD. g (OnStar®/Voice Recognition): If your vehicle has the Radio with CD or Radio with Six-Disc CD audio system, press this button to interact with the OnStar® system. 310