As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5607, CMH TO IAH - AT FL310 THE CREW RECEIVED AN APU OIL PRESSURE MESSAGE ON EICAS. THE CREW FOLLOWED THE QRH AND DIVERTED TO SDF WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE APU OIL LEVEL LOW. THE APU WAS SERVICED WITH 1QT OF BP2380 OIL IAW 12-13-49. OPERATIONAL CHECKS GOOD, NO DEFECTS OR LEAKS NOTED.