As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT DIVERTED TO ONT AFTER DEPARTURE FROM PHX DUE TO APU FIRE WARNING INDICATION. APU FIRE BOTTLE BLOWN DUE TO FIRE INDICATION. *S/D* APU TAILPIPE OVERHEAT LOOP, M515, WAS SHORTED TO GROUND. ELEMENT LOOP M515 WAS REPLACED AND PROPERLY POSITIONED ON THE AIRCRAFT. APU EXTINGUISHING BOTTLE, ASSOCIATED SQUIB, AND INDICATOR DISCS WERE ALSO REPLACED.