As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU ALTITUDE START FAILED AT ALTITUDE LEVEL 350, FAULT LIGHT ILLUMINATED. SUPPLEMENTAL DATA UPDATE, FOUND THE TORQUE MOTOR CANNON PLUG CONNECTOR DIRTY AND LOOSE. CLEANED AND SECURED CANNON PLUG. REPLACED THE FUEL CONTROL UNIT, THE IGNITION EXCITER BOX AND IGNITER AS PRECAUTION. SYSTEM CHECKED OK WITH APU TESTER. APU ALTITUDE START IS OPERATING NORMALLY.