As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FILTER DPI FOUND EXTENDED DURING PDC WALKAROUND. ACFT GROUNDED. REF AMM 49-91-13 INSPECTED APU LUBE FILTER ELEMENT AND FOUND DPI INDICATOR EXTENDED. REMOVED FILTER AND INSPECTED NO DEFECTS NOTED. MAGNETIC PLUG CLEAN. REPLACED FILTER. LEAK CHECK OF APU CHECKS OK.