As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO THE FIELD DUE TO SMOKE IN THE CABIN. AFTER RETURN TO GATE FOR SMOKE IN CABIN BEGAN CLEANING APU BLEED COMPONENTS AND DUCTS. FOUND AND CLEANED OIL IN DUCTS AS FAR AS APU FIRE BOTTLE ACCESS DOOR. NEED TO CHECK DUCTS THRU AFT BODY ACCESS DOOR FOR ANY ADDITIONAL OIL. OIL IS PUDDLING IN LOWER SECTIONS OF DUCTS AND IN FLANGES. ALL DUCTS CHECKED AND CLEANED.