As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) FLIGHT RETURNED DUE TO APU OIL PRESSURE MESSAGE CAUSING THE APU TO FAIL. AIRCRAFT WAS ALREADY OPERATING WITH 1 IDG GENERATOR UNSERVICEABLE. MAINTENANCE CHECKED THE SYSTEM AND FOUND AN ECU FAULT MESSAGE. THE APU ECU WAS REPLACED AND THE A/C WAS CHECKED SERVICEABLE. NR 1 IDG WAS ALSO REPLACED AT THIS TIME AND CHECKED SERVICEABLE CLEARING THE MEL. CYCLES SINCE OVERHAUL:4860 (TC NR 20071103001)