As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI, THE CREW OBSERVED SMOKE IN THE CABIN, AND A LAV SMOKE WARNING MESSAGE. THE CREW DEPLANED THE AIRCRAFT AND AN EMERGENCY WAS DECLARED. PIT MAINTENANCE INSPECTED AND OPERATION CHECKED THE LEFT AND RIGHT AIRCONDITIONING SYSTEMS, AND THE LAV SMOKE SYSTEM IN ACCORDANCE WITH DORNIER MAINTENANCE MANUALS 21-51-00 AND 26-15-00. NO DEFECTS WERE NOTED AND THE AIRCRAFT WAS RETURNED TO SERVICE.