What was found
CYAN "FIRE SYS FAULT" MESSAGE ILLUMINATED INTERMITTENTLY DURING FLIGHT. REMOVED AND REPLACED APU EDUCATOR FIRE LOOP A104 (IAW AMM 26-13-05; PN 446701-4 AND SN 01120196327). REMOVED AND REPLACED APU FIRE WALL LOOP A103 (IAW AMM 26-13-01; PN 446701-3 AND SN 01220196328). REMOVED AND INSTALLED MODIFIED FIRE EX CONTROL UNIT IAW AMM 26-11-01. OPS CHECK GOOD. ALSO VISUALLY INSPECTED THE APU SURGE VALVE, CLAMP, CONNECTOR, AND THE FIRE LOOP IN CLOSE PROXIMITY TO THE VALVE, NO DEFECTS NOTED.