As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON APU START UP RECEIVED A BLUE MAINT LIGHT. GROUNDED - YES. VERIFY BLUE MAINT LIGHT WAS ON, SHUT DOWN APU AND THEN I STARTED APU AGAIN AND RAN IT FOR 5 MIN AND BLUE MAINT LIGHT WENT OFF. PERFORMED BITE CHECK AND OIL LEVEL WAS FULL. GROUND VERIFICATION CHECK GOOD REF FIM 49-90 TASK 804. NO FAULT LIGHT ON A/C OK FOR SERVICE.