As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU WONT START, FAULT LIGHT ON AFTER START ATTEMPT. GROUNDED - YES. PERFORMED BITE TEST AND FOUND MAINT MSG 49-61223. "INLET TEMPERATURE SENSOR SHOWS SHORT CIRCUIT". T/S TO INLET TEMP SENSOR IAW B737-800 FIM 49-60 TAK 812. REPLACED INLET TEMP SENSOR IN REF TO B737-800 AMM 49-61-31, OPS GOOD NO FAULT CODES NOTED.