As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - ON FLIGHT 2515, AFTER TAKEOFF, AFT LAV SMOKE WARNING. HOT ODOR IN CABIN, WENT AWAY AFTER 1.5 MINUTES. EMERGENCY DECLARED. RETURNED TO PDX, LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED APU. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.