As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER APU SHUT DOWN LIGHT SMOKE FROM APU INLET. REMOVED FROM SERVICE. PERFORMED GVI ON APU INLET NO DEFECTS NOTED. INTERROGATED CMC NO FAULTS DETECTED. PERFORMED APU OPS TEST IAW E175 AMM 49-10-00-700-801-A. OPS TEST GOOD. NO SMOKE DETECTED ON SHUT DOWN. AC OK FOR RTS. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.