As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED SMOKE IN CABIN. AIRCRAFT RETURNED TO AIRPORT LANDING WITHOUT ISSUE. MAINTENANCE TROUBLESHOT, REMOVED, AND REPLACED THE CARBON SEAL ON THE LEFT ENGINE. OPERATIONAL CHECKS WERE PERFORMED USING THE AIRCRAFT MAINTENANCE MANUAL. AIRCRAFT WAS RELEASED FOR SERVICE.