As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED SMOKE TOILET AMBER MESSAGE ALONG WITH SMOKE IN COCKPIT AND CABIN. AIRCRAFT RETURNED TO AIRPORT LANDING WITHOUT ISSUE. MAINTENANCE TROUBLESHOT, REMOVED,AND REPLACED THE LEFT AIR CYCLE MACHINE. OPERATIONAL CHECKS WERE PERFORMED USING THE AIRCRAFT MAINTENANCE MANUAL. AIRCRAFT WAS RELEASED FOR SERVICE.