As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING INITIAL CLIMB OUT "LAV SMOKE WARNING MESSAGE" AFTER 2 MINUTES IT STOPPED AND MESSAGE CLEARED. NO SMOKE OR SMELL IN LAV AT ANYTIME. MX REMOVED AND REPLACED THE LAV SMOKE DETECTOR PANEL WITH OPERATIONAL CHECK GOOD. A/C WAS APPROVED FOR RETURN TO SERVICE.