GMC YUKON XL 2004 Owner's Manual page 247

When a message is not available from a station,
NO INFO will appear on the display.
TRAF (Traffic): If TRAF appears on the display, the
tuned station broadcasts traffic announcements
and when a traffic announcement comes on the tuned
radio station you will hear it.
If the current tuned station does not broadcast traffic
announcements, press this button and the radio
will seek to a station that does. When the radio finds a
station that broadcasts traffic announcements, it will
stop and TRAF will be displayed. When a traffic
announcement comes on the tuned radio station you
will hear it. If no station is found, NO TRAFFIC will
appear on the display.
If TRAF is on the display you can press the TRAF
button to turn off the traffic announcements.
Your radio will play the traffic announcement even if the
volume is low. Your radio will interrupt the play of a
CD if the last tuned station broadcasts traffic
announcements.
This function does not apply to XM™ Satellite Radio
Service.
Radio Messages
CAL ERR (Calibration Error): Your audio system has
been calibrated for your vehicle from the factory. If
CAL ERR appears on the display, it means that your
radio has not been configured properly for the vehicle
and must be returned to the dealer for service.
LOCKED: This message is displayed when the
®
THEFTLOCK system has locked up. You must return
to the dealer for service.
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