As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON DESCENT, CREW STARTED APU, TRANSFERRED BLEEDS AND SMELLED OIL SMELL AND SAW APU ITT IN YELLOW. CREW REPORTED SMELL GETTING WORSE AND TRANSFERRED BLEEDS BACK TO ENGINES AND THEN GOT APU FIRE FAIL AMBER MESSAGE. CREW TURNED OFF APU AND LANDED WITHOUT INCIDENT. APU DOOR INHIBIT MESSAGE WAS SUBSEQUENTLY REPORTED. MAINTENANCE TROUBLESHOT APU, REMOVED AND REPLACED APU LCV (LOAD CONTROL VALVE) AND PERFORMED CHECKS USING AIRCRAFT MAINTENANCE MANUALS. AIRCRAFT RELEASED FOR SERVICE.