As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED A LAV SMOKE WARNING APPROXIMATELY 2 MINUTES AFTER TAKEOFF. NO SIGNS OF SMOKE OR ODOR WERE FOUND. THE FLIGHT THEN RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED THE LAV SMOKE DETECTOR AND LAV SMOKE DETECTOR CONTROL PANEL AND NO FURTHER INDICATIONS WERE PRESENT.