As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BLUE MAINTENANCE LIGHT CAME ON DURING APU START. APU DID START NORMALLY, GOOD VOLTS AND FREQUENCIES- STEADY BLUE APU BEN LIGHT. ACFT GROUNDED. ADDED 1.5 QTS TO APU. FOUND FAULT CODE 49-91227 LOW OIL QTY OK FOR SERVICE IAW FIM 49-90 TASK 804 SEAM C.