As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 2220 SHV-IAH - THE CREW REPORTED A MOMENTARY LAVATORY SMOKE WARNING DURING CRUISE. NO SMOKE CONDITIONS WERE NOTED AT THAT POINT AND THE AIRCRAFT LANDED AT IAH WITHOUT INCIDENT. MAINTENANCE PERFORMED ENGINE GROUND RUNS AND COULD NOT DUPLICATE THE CONDITION.