As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAX - FOUND CABIN BEGAN TO FILL WITH FUMES/SMOKE WITH APU OPERATING ON DESCENT INTO LAX. SHUTDOWN APU, AND FUMES/SMOKE DISSIPATED. PERFORMED TASK CARD 28525011 DUCT CLEANING PROCEDURE AND REPLACED COALESCER BAGS. NO APU DEFECTS FOUND. OP CHECKED OK ON GROUND. (M)