As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DUCT PRESSURES FROM APU ZERO WITH APU RUNNING, APU BLEED SWITCH ON, ISOLATION VALVES OPEN, AND ENGINE (BLEED) OFF LIGHTS DISPLAYED ON BOTH ENGINES. REPLACED APU FLOW SENSING MODULE DUE TO FAULTS ON ECU, OPS CHECKED GOOD WITH PACKS ON & ENG MOTOR. ECU MEM CLEARED.