As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FAILED START AT FL400, FL400, FL300 AND FAILED START ON THE GROUND. GROUNDED - YES. DURING INIT EVALUATION "APU FAULT" LIGHT CAME ON WHEN TRYING TO START, 3 TIMES. APU BITE TEST SHOWED "49-15004 INLET DOOR SHUTDOWN." ACCOMPLISHED FIM TASK 49-10 TASK 806 STEP E(1). APU STARTED SUCCESSFULLY 3 TIMES WITH NO FAULTS OR MAINTENANCE MESSAGES.