As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THAT THEY RECEIVED A LAVATORY SMOKE MESSAGE ON CLIMB OUT. THE CREW FURTHER REPORTED NO VISIBLE SMOKE. THE SMELL OF DE-ICING FLUID WAS REPORTED AS PRESENT IN THE AIRCRAFT. THE CREW RETURNED TO FIELD & LANDED WITHOUT INCIDENT. MX RAN THE ENGS WITH NO DEFECTS NOTED & THE ACFT WAS RETURNED TO SERVICE.