As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FLT 642 - EN ROUTE, RIGHT IDG WAS DISCONNECTED AND THE APU WAS OPERATING. CREW RECEIVED THE E/M 'APU OIL QTY.' FLIGHT DIVERTED TO PIT AND LANDED. UPON LANDING, THE APU PERFORMED AN AUTO SHUTDOWN. MAINTENANCE REPLACED SEVERAL PARTS, HOWEVER THE APU CONTINUED TO FAULT DUE TO LOW OIL QUANTITY. THE APU WAS REPLACED. (M)