This Preliminary Information communication provides information to the technician about vehicles that radio is inoperative, loss of sound, or their display is blank. Technician will need to cycle power to the radio and retest. If the radio starts working advise the customer that we apologize for this inconvenience and that General Motors is working on a permanent solution for this concern. If the radio is still inoperative technician will need to test the power, ground, and circuit 5060 circuits. If no concern with power, ground, circuit 5060 or connections, replace the radio.