As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ASH 6216 PHX-PHX - THE CREW RETURNED THE AIRCRAFT TO THE FIELD DUE TO THE AFT LAVATORY SMOKE DETECTOR SOUNDING FOR APPROXIMATELY 8 SECONDS AND THE FLIGHT ATTENDANT NOTICING AN UNUSUAL ODOR AT THE AFT LAVATORY AREA. MAINTENANCE INSPECTED THE LAVATORY AREA AND PERFORMED ENGINE RUNS WITH NO DEFECTS NOTED.