As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU BLEED AIR APUC DETECTED LOSS OF ABILITY TO PNEUMATICALLY LOAD APU. MESSAGE IS TRIGGERED BY IGV OR SURGE CONTROL SYSTEM FAULTS. APU BLEED AIR FAULT. APU BLEED WORKS BUT MESSAGE IS LATCHED. SURGE CONTROL VALVE IS IN DISAGREEMENT. REPLACED SURGE VALVE.