As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAXI OUT, 'APU DOOR OPEN' LIGHT ILLUMINATED WHEN FLIGHT CREW ATTEMPTED APU SHUT DOWN. CAPTAIN ELECTED TO RETURN TO GATE. AFTER RETURN TO GATE AND SHUT DOWN OF NR 1 AND NR 3 ENGINE, APU DOOR CLOSED AND LIGHT EXTINGUISHED. MAINTENANCE PERSONNEL RECYCLED APU DOOR. OPS CHECK OKAY. AIRCRAFT RETURNED TO SERVICE. (X)