As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD FLT 5821 THE CREW REPORTED A LAV SMOKE WARNING MESSAGE ON TAKEOFF. ALSO REPORTED A SMOKE SMELL. NO SMOKE WAS NOTED. THE AIRCRAFT RETURNED TO IAD AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED AND REPLACED THE NR 2 ENGINE CVG ACTUATOR. OPERATIONAL CHECKS WERE GOOD.