As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT "FAULT LIGHT" ON APU WAS FOUND ILLUMINATED. CLEANED AND INSPECTED INLET SENSOR WIRING AND ELECTRICAL CONNECTOR P21. PERFORMED RESISTANCE CHECK OF SENSOR NO DEFECTS FOUND. PERFORMED BITE TEST REF FIM 49 60 00 810 812 NO FAULTS AND APU OPS CHECKS NORMAL. OK FOR SERVICE.