RMFerrari

Hi, I new here and I need help with a issue, I own a Audi A3 1.8T 2005 (8L), with Radio Symphony II without changer and without Bose speakers. I used my Alpine head unit for 2 years, now I put the original Stereo from Audi but the illumination don't appear, the radio don't turn on when I turn on the car and don't show the track/station information on dash LCD, I know that is a CAN-BUS problem, I checked the two wires CAN-BUS that connects to the radio and have 10volts the H, the L have 4 volts, I don't remember exact, but appears that the CAN-BUS is sending information to the radio, why the radio don't turn on by it self? Why the illumination don't appear? Do I need to use a VAG-COM at a dealer to "turn-on" again this function?

Thank you.