2009 GMC Sierra 1500 Crew Cab Owner's Manual - Page 325

b g (Mute/Push to Talk): Press to silence the vehicle speakers only. Press again to turn the sound on. For vehicles with OnStar® or Bluetooth® systems press and hold b g for longer than two seconds to interact with those systems. See OnStar® System on page 2-70 and Bluetooth® on page 3-118 in this manual for more information. SRCE (Source/Voice Recognition): Press to switch between the radio (AM, FM, XM), CD, DVD (if equipped), front auxiliary (if equipped), and rear auxiliary (if equipped). For vehicles with the navigation system, press and hold this button for longer than one second to initiate voice recognition. See "Voice Recognition" in the Navigation System manual for more information. + e − e (Volume): Press to increase or to decrease the radio volume. Press to go to the next radio station while in AM, FM, or XM™. Press ¨to go to the next track or chapter while sourced to the CD or DVD slot. Press the ¨if multiple discs are loaded to go to the next disc while sourced to a CD player. Radio Reception Frequency interference and static can occur during normal radio reception if items such as cell phone 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. 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 the radio. FM Stereo FM signals only reach about 10 to 40 miles (16 to 65 km). Although the radio has a built-in electronic circuit that automatically works to reduce interference, some static can occur, especially around tall buildings or hills, causing the sound to fade in and out. ¨(Seek): 3-141