As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
B-LOOP SYSTEM OF MANIFOLD FAULT DETECTION DOES NOT TEST PROPERLY. APU MANIFOLD FAULTS B-LOOP. NR 2 WINGS MANIFOLD FAULTS B-INOP. APU BLEED VALVE SECURED CLOSED. REMOVED AND REPLACED NR 2 SYS CFD CONTROL UNIT PER MM REF 26-16-10. SYS OPS CHECKS GOOD. OK TO CONTINUE.