As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU LOW OIL PRESSURE IN FLIGHT. RETURNED TO SLC. REMOVED AND REPLACED APU OIL PRESSURE SWITCH IAW A/C MM 41-91-20. ALSO REMOVED AND REPLACED APU ECU. (P/N 2118800-2) (S/N ON 66-F0139) (S/N OFF 44-F0007) IAW A/C MM 49-61-01. OPS CHECKED AND LEAK CHECKED GOOD.