As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FAULT, SHUTDOWN DURING POWER TRANSFER. BIT CHECKED THE APU ECU AND FOUND IT WAS FLAGGING LOW OIL PRESSURE IAW FIM 49-11 FT 987. REMOVED AND REPLACED APU LOW OIL PRESSURE SWITCH, IAW AMM 49-94-02. OPS CHECKED OK. CLEARED APU FAULT AND DOOR STATUS FAULT.