As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5650, ELP TO IAH, DURING CRUISE WITH THE NR 2 IDG ON DEFERRAL, REQUIRING THE APU TO BE RUN THE ENTIRE FLIGHT, THE CREW RECEIVED AN APU HIGH OIL TEMPERATURE MESSAGE. THE QRH WAS FOLLOWED AND THE AIRCRAFT DIVERTED TO KMAF WERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THAT THE APU WAS OVER SERVICED AND DRAINED 1/2 A QUART OF OIL FROM THE APU AND THE SYSTEM OPERATED NORMALLY. THE FAULT RETURNED THE NEXT DAY DURING GROUND OPERATIONS AND DURING TROUBLE-SHOOTING THE APU OIL COOLER WAS FOUND CLOGGED AND WAS REPLACED. THE APU OIL TEMPS WERE NORMAL WITH NO OTHER DEFECTS NOTED.