As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FMU REQUIRES REPLACEMENT FOR TROUBLESHOOTING OF OIL LEAK. REPLACED APU FMU. ACCOMPLISHED ECU BITE FOUND AUTO SHUTDOWN LOP MSGS. DURING LEAK CHECKS FOUND FMU ATTACHMENT FLANGE CASTING LEAKING UNDER PRESSURE FROM HAIRLINE CRACK. UNABLE TO LOCATE IN IPC ENGINEERING ASSISTANCE REQUIRED. NBRS ON CASTING 99193-3880133-3 OR MFR 5V132 OR CDA-81833. REPLACED APU. OPS CHECK, LEAK CHECK NORMAL.