2004 GMC Envoy Owner's Manual - Page 238

The front seat audio controls always have priority over the RSA controls. If the front seat passengers switch the source for the main radio to a remote source, the RSA will not be able to control the source. You can operate the rear seat audio when the main radio is off. SRCE (Source): Press this button to select a source: radio, cassette tape, CD, or DVD. The inactive tape, CD, or DVD will remain safely inside the radio for future listening. SEEK: Press this button to go to the next station and stay there. The display will show the selection. This function is inactive if the front seat passengers are listening to the radio. To scan preset stations, press and hold the SEEK button. The radio will go to a preset station, play for a few seconds, then go the next preset station. The display will show the selections. This function is inactive if the front seat passengers are listening to the radio. When a cassette tape is playing, press the SEEK button to go to the next selection on the tape. Press and hold the SEEK button to go to the other side of the tape. This function is inactive if the front seat passengers are listening to a cassette tape. When a CD is playing, press the SEEK button to go to the next track on the CD. This function is inactive if the front seat passengers are listening to a CD. When a CD is playing in the six-disc CD player, press and hold the SEEK button for 2 seconds to go you to the next CD, if multiple CDs are loaded. This function is inactive if the front seat passengers are listening to a CD. P (Power): Press this button to turn the system on or off. The rear speakers will be muted when the power is turned on unless you have a Bose® equipped vehicle. u (Volume): Turn this knob to increase or to decrease the volume. The left volume knob controls the left headphones and the right volume knob controls the right headphones. 3-118