What was found
FUMES ON APPROACH AND LANDING , TURNED OFF ENGINE BLEED 1 AND 2, FUMES SUBSIDED RAN FUMES CHECKLIST. PERFORMED TSM 05-50-00 FOR THE CAUSE OF CABIN ODOR, RAN BOTH ENGINES BY FLT CREW , NO ODOR NOTED ON EITHER PACK , SUSPECT APU FOR CAUSE OF ODOR.