GMC 2009 Sierra - Manual (Page 257)

If your vehicle has 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.
If your vehicle has OnStar ® , press and hold this button
for longer than one second to interact with the
OnStar
® system. If your vehicle also has the navigation
system, press and hold this button for longer than
one second to initiate voice recognition and say “OnStar”
to enter OnStar
® mode. See the OnStar ® System on
page 2-45 in this manual for more information.
SRCE (Source): Press this button to switch between
the radio (AM, FM), XM™ (if equipped), CD, and if your
vehicle has these features, DVD, front auxiliary, and
rear auxiliary.
+
e − e
(Volume): Press the plus or minus volume
button to increase or to decrease the radio volume.
¨
(Seek): Press the seek arrow to go to the next
radio station while in AM, FM, or XM™ (if equipped).
Press the seek arrow to go to the next track or chapter
while sourced to the CD or DVD slot.
Press the seek arrow to go to the next disc while sourced
to a six-disc CD player, if multiple discs are loaded.
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
your radio.
FM Stereo
FM stereo gives the best sound, but FM signals only
reach 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.
3-121