As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU WONT START (LOW OIL PRESSURE AND FAULT LT ON). GROUNDED - YES. PERFORMED APU BITE B737-800 FIM 49-60-TASK 801. NO ACTIVE FAULTS FOUND. HISTORY SHOWED SEVERAL 49-15004. DUE TO HISTORY REMOVED AND REPLACED ECU REF B737-800 49-61-12/401. STARTED AND RAN APU 4X WITH NO DEFECTS. REF AMM 49-11-00-860-801. SYS OPS NML.