2004 GMC Yukon Owner's Manual - Page 271

BAND (Alternate Frequency): Alternate frequency allows the radio to switch to a stronger station with the same program type. To turn alternate frequency on, press and hold BAND for two seconds. AF ON will appear on the display. The radio may switch to stations with a stronger frequency. To turn alternate frequency off, press and hold BAND again for two seconds. AF OFF will appear on the display. The radio will not switch to other stations. This function does not apply for XM™ Satellite Radio Service. Setting Preset PTYs (RDS Only) Up to 12 PTYs (six FM1 and six FM2), can be programmed on the six numbered pushbuttons, by performing the following steps: 1. Press BAND to select FM1 or FM2. 2. Press the P-TYPE button to activate program type select mode. P-TYPE and the last selected PTY will appear on the display. 3. Turn the P-TYPE knob to select a PTY. 4. Press and hold one of the six numbered pushbuttons until you hear a beep. Whenever that numbered pushbutton is pressed, the PTY that was set will return. 5. Repeat the steps for each pushbutton. 3-113