As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN AUXILIARY PWR UNIT BLEED SELECTED ON ODOR IN CABIN WAS NOTED AND LAV SMOKE DETECTOR ACTIVATED. NO SMOKE SEEN. NO DIFFICULTIES FOUND WITH SMOKE DETECTOR IN LAVATORY. INSPECTED, NO LEAKS NOTED. APU APPEARS TO BE BURNING OIL. EXHAUST AND OR FUMES ENTERED CABIN THRU AIR STAIR DOOR OPENING.