As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYS - APU FAULT EICAS MSG. AFTER LANDING. PERFORMED APU ECU BITE PROCEDURE. ECU FAULTS REVERSE FLOW. FAULT NOT ASSOCIATED WITH START. FOUND APU COLD SOAKED. APU START NORMAL ON FIRST ATTEMPT. APU BITE C/W IAW FIM 49-11-00.