2008 GMC Envoy Owner's Manual - Page 236

PROG (Program): Press this button to play a station that has been programmed on the radio preset pushbuttons. The radio seeks preset stations only with a strong signal that are in the selected band. When a CD is playing in the CD changer, press this button to go to the next available CD, if multiple CDs are loaded. Radio Reception Frequency interference and static during normal radio reception can occur if items such as cellphone chargers, vehicle convenience accessories, and external electronic devices are plugged into the accessory power outlet. If there is interference or static, unplug the item from the accessory power outlet. Q SOURCE R: Press the SOURCE arrows to switch between FM1, FM2, AM, or XM1 or XM2 (if equipped), or a CD. If a CD is loaded the CD symbol displays. Q SEEK R: Press the SEEK arrows to go to the previous or the next radio station and stay there. The radio seeks stations only with a strong signal that are in the selected band. When a CD is playing, press the SEEK arrows to fast forward or reverse. Press the VOL arrows to increase or to decrease the volume. AM The range for most AM stations is greater than for FM, especially at night. The longer range can cause station frequencies to interfere with each other. For better radio reception, most AM radio stations boost the power levels during the day, and then reduce these levels during the night. Static can also occur when things like storms and power lines interfere with radio reception. When this happens, try reducing the treble on your radio. Q VOL R (Volume): FM Stereo FM stereo gives the best sound, but FM signals reach only about 10 to 40 miles (16 to 65 km). Tall buildings or hills can interfere with FM signals, causing the sound to fade in and out. 3-102