Chevrolet 2004 Impala Owner's Manual page 194

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 the TRAF button and the
radio will seek to a station that does. When the radio
finds a station that broadcasts traffic announcements,
the radio 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 TRAF
will appear on the display.
If TRAF is on the display you can press the TRAF
button to turn of the traffic announcements.
Your radio will play the traffic announcement even if the
volume is muted. 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.
3-72
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 the 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.
If any error occurs repeatedly or if an error cannot be
corrected, contact your dealer.