As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE WARNING AT GATE AND APU SHUTDOWN AUTOMATICALLY. SLIGHT ABNORMAL SMELL NOTICED AFTER STARTING APU ON DECENT AND SMELL IT ON THE GROUND OUTSIDE. (FLIGHT# 5403) PERFORMED APU INSPECTION IN REF TO AMM 49-61-00 AND AMM 49-61-03, FOUND 2 WIRES DAMAGED GOING TO APU EGT2 SENSOR, APU FIRE BOTTLE DID NOT DEPLOY, NO RESIDUAL FIRE OR APU DAMAGE NOTED AT THIS TIME, A/C OK FOR SVC.