What was found
(CAN) DURING FLIGHT, POWER PLANT MESSAGE POSTED ON ED. FLIGHT CREW OPTED TO RETURN TO DEPARTURE. ON GROUND TROUBLESHOOTING FOUND FOLLOWING FADEC/PEC FAULT CODES ON THE NR 1 SIDE, CHANNEL A 476, 478, 456, 454, 711, 765, 932 - EMU CHANNEL A 476,478,750,751,752,753. AFTER ATTEMPTING FAULT CLEAR THE POWER PLANT MESSAGE REMAINS WITH FOLLOWING FAULTS ON FADEC A CHANNEL 20,763,765,809,932 B CHANNEL 10,454,456,478. OPERATOR REPLACED NR 1 FADEC. FUNCTION TEST`S CARRIED OUT WITH NO FAULTS , ACFT WAS RETURNED TO SERVICE.