As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PACKS ON APU PUT OUT EXCESSIVE WATER VAPOR WITH A SLIGHT OIL SMELL. PACKS ARE NORMAL ON ENG NO MAINTENANCE MESSAGES ON OMF 21 EXISTING FAULTS. DE HUMIDIFIED LEFT PACK. RAN PACKS TO PERFORM OPS CHECK. PROBLEM NO LONGER PRESENT. FAULT FIXED. REF 21-51-00