As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FAULT LIGHT ILLUMINATED ON START AT GATE. FOUND FAULT CODE 49 61224. TROUBLESHOT TO FAULTY INLET TEMPERATURE SENSOR PER FIM TASK 49 60 00 813. REMOVED AND REPLACED APU INLET TEMPERATURE SENSOR IAW AMM 49 61 31 000 801. OPERATED APU. NO FAULTS NOTED.