As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN FLIGHT APU OIL TEMP CAUTION MESSAGE ON EICAS. DUE TO NR 2 GENERATOR MEL HAD TO RETURN TO RDU. REMOVED AND REPLACED APU OIL TEMP SENSOR IAW CRJ AMM 49-91-25. PERFORMED OPS AND LEAK CHECKS IAW CRJ AMM 49-10-00. ALL OPS AND LEAK CHECKS GOOD.