2007 Chevrolet TrailBlazer Owner's Manual - Page 204

Radio/Compact Disc Messages (CAL ERR): This message is displayed when the radio has not been calibrated properly for the vehicle. You must return to the dealership for service. (LOCKED): This message is displayed when the THEFTLOCKR system has locked up. You must return to the dealership for service. (Err): If you're driving on a very rough road or if it's very hot, the disc may not play and Err (error) may appear on the display. When the road becomes smooth or the temperature returns to normal, the disc should play. If the disc comes out, it could be one of the following: AM-FM Stereo with Cassette Tape and Compact Disc Player with Radio Data System (RDS) and Automatic Tone Control (If Equipped) D The disc is upside down. D It is dirty, scratched or wet. D It is very humid. (If so, wait about an hour and try again.) If any error occurs repeatedly or if an error can't be corrected, please contact your dealer. Standard Radio--BoseR not shown Playing the Radio VOL PWR: Press this control to turn the system on and off. Turn this control clockwise to increase volume. Turn it counterclockwise to decrease volume. 3-32