2003 GMC Sonoma Owner's Manual - Page 176

AM FM (Alternate Frequency): Alternate frequency allows the radio to switch to a stronger station with the same program type. Press and hold AM FM for two seconds to turn alternate frequency on. AF ON will appear OK the display. The radio may switch lo stronger stations. Press and hold AM FM again for two seconds to turn alternate frequency off. AF OFF will appear on the display. The radio will not switch to other stations. When you turn the ignition off and then on again, the alternate frequency feature will automatically be turned on. If the whole message is not displayed, parts of it will appear every three seconds. To scroll through the message at your own speed, press the INFO button repeatedly. A new group of words will appear on the display with each press. Once the complete message has been displayed, the information symbol will disappear from the display until another new message is received. The old message can be displayed by pressing the INFO button until a new message is received or a different station is tuned to. When a message is not available from an station, NO INFO will be displayed. TRAF (Traffic): Press this button to receive traffic announcements. If the current tuned station does not broadcast traffic announcements, the radio will seek to a station that does. When the radio finds a station that broadcasts traffic announcements, it will stop. TRAF will appear on the display and when a traffic announcement comes on you will hear it. If no station is found, NO TRAF will appear on the display. When a traffic announcement comes on the current station or on a related network station, you will hear it, even if the volume is muted or a compact disc is playing. The traffic symbol and TRAF will appear on the display while the announcement plays. If the compact disc player was being used, play will stop during the announcement. RDS Messages ALERT!: Alert warns of local or national emergencies. When an alert announcement comes on the current radio station, ALERT! will appear on the display. You will hear the announcement, even if the volume is muted or a compact disc is playing. If the compact disc player is playing, play will stop during the announcement. You will not be able to turn off alert announcements. ALERT! will not be affected by tests of the emergency broadcast system. This feature is not supported by all RDS stations. INFO (Information): If the current station has a message, the information symbol will appear on the display. Press this buttonto see the message. The message may display the artist and song title, call in phone numbers, etc. 3-49