As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LANDING DURING TAXI IN, ATTEMPTED ONE START ON APU. APU FAILED TO START WITH LOW OIL PRESSURE LIGHT ILLUMINATED. GROUNDED YES. PERFORMED APU BITE REF FIM 49-60, TASK 801. FOUND FAULT 49-11-019. PERFORMED FIM TASK 49-10-00-810-801. APU OPERATES NORMAL.