As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AMBER LAVATORY SMOKE ADVISORY MESSAGE ON EICAS DISPLAYED ALONG WITH CHIMES IN CABIN AND SMOKE DETECTED FOR LAV 4RC INDICATED AT DOOR 2L PANEL, NO SMOKE EVIDENCE FOUND. ACCOMPLISHED SMOKE DETECTOR SELF TEST IAW AMM 26-13-00 AND SOF INSPECTION IAW MCM 72L00021001, OPS CHECK GOOD.