As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU AUTO SHUTDOWN ECU SHOWS "GEN FILTER" IN 2 OF THE LAST 4 SHUTDOWNS. IAW FIM49-11-00 CONF 2 PG 146 ITM2 SWITCH NEEDS TO BE CHECKED FOR RESISTANCE. PCN 481-1503 ORDERED. IAW AMM 49-27-15, AMM 49-27-03, AMM 49-27-04, CHECKED CHIP DETECTOR FOUND OK. REPLACED GEN FILT DIFF P SWITCH & CHANGED GEN FILTER. APU OPERATES NORMALLY.