As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU OIL FILTER LUBE UNIT FILTER DELTA "P" POPPED. GROUNDED - YES. REMOVED AND REPLACED APU LUBE UNIT OIL FILTER ELEMENT REF B737-800 AMM 49-91-12 OIL FILTER APPEARED TO BE CLEAN. REMOVED AND REPLACED APU OIL FILTER INDICATOR REF AMM 49-91-13. APU OIL FILTER HOUSING AND INDICATOR LEAK CHECK. GOOD NO LEAKS NOTED REF AMM 49-91-12. OIL FILTER DELTA P INDICATOR REMAINED RESET.