As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU INFLIGHT START WAS NOT SUCCESSFUL. MAX EGT RECEIVED WAS 812' AND MAX RPM REACHED WAS 53 PERCENT. RPM ACCELERATION SEEMED VERY SLOW. APU FAULT ANNUNCIATED. REPLACED APU ECU IAW AMM 49-61-05-004-001. SECURITY CONDITION GOOD. OPS CHECK GOOD.