As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: LAVATORY SMOKE WARNING. NO EVIDENCE OF SMOKE OR FUME OR FIRE. MAINTENANCE FOUND NO FAULT INDICATED AFTER CREW DEPARTED. PERFORMED SMOKE DETECTOR OPERATIONAL CHECK THROUGH MCDU PER AMM 26-17-00 WITH NO DEFECTS NOTED.