What was found
ACFT RETURNED TO GATE, APU AUTO SHUTDOWN. OIL CHIP DETECTION MESSAGE 499111. TROUBLESHOT IAW TSM 49-62-00-810-915-A, REPLACED SCAVANGE/LUBE FILTERS IAW AMM 49-91-41, COLLECTED OIL SAMPLES, NO METAL NOTED. INSPECTED CHIP DETECTOR, AND FOUND SMALL METAL PARTICLES, COLLECTED SAMPLES. CLEANED CHIP DETECTOR, OPS NORMAL.