As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU AIR PRESSURE LOW DURING START (11 PSI)DURING LH ENGINE START HUNG AT 25% N2 ON TAXI OUT. AC RETURNED TO GATE (BTB) . MTX GROUNDED AC AND DEFERRED APU IAW MEL ABX-49-11-1A ACCOMPLISHED MPM PLACARD INSTALLED AND AC REMAINS NO ETOPS MBCB 12-20-2024 AC RETURNED TO SERVICE .