As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON APU START THE FAULT LIGHT CAME ON AND SMOKE WAS OBSERVED COMING OUT OF THE APU EXHAUST. ACCOMPLISHED FIM TASK 49-40, TASK 802, NO FLAME SHUTDOWN, MAINT MESSAGE 49-41011. REPLACED IGNITER PLUG AND IGNITION EXCITER REF MM 49-41-51 AND 49-41-31.