As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING WALK AROUND APU SHUTDOWN UNCOMMANDED. GROUNDED - YES. RAN B737-900 FIM TASK 49-60 801 APU BITE. FAULT HAS 49-91005, HIGH OIL TEMP SHUTDOWN STATED. FIM TASK 49-90 #801 GVI OIL COOLER AND MAGNETIC DRAIN PLUG. NO DEFECTS NOTED. REPLACED MAG DRAIN PLUG PACKINGS, LEAK CK OK REF B737-900 AMM 49-91-81. PERFORMED AMM TASK 49-21-00-980-801 & FIM TASK 49-30-803. REMOVED & REPLACED APU OIL COOLER IAW AMM 49-91-41. NO LEAKS NOTED. NO CURRENT APU FAULTS.