What was found
DURING CLIMB OUT, RECEIVED APU FAULT EICAS MESSAGE DURING AN APU VERIFICATION FLIGHT. FAILED VERIFICATION. COMPLIED WITH QRH APU STARTED. PERFORMED APU BITE TEST SHOWS P2 SENSOR ON SUMMARY, MINI FLAG 16, REMOVED AND REPLACED THE ECU IAW AMM 49-61-05-004-001. OPS CHECKED OK. FIRST START OK, APU RAN FOR MORE THAN 1 HOUR, NO FAULTS NOTED.