As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: SMOKE LAVATORY SMOKE ELECTRONIC CENTRALIZED AIRCRAFT MONITOR MESSAGE IN FLIGHT. 2L AFT LAFT LAVATORY. PASSENGER IN QUESTION DENIED SMOKING. ACCOMPLISHED OPERATIONAL TEST OF 2L LAVATORY PER AMM 26-17-00 AND NO DEFECTS NOTED.