As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU HAS ADDITIONAL REPORTS OF AUTO SHUTDOWN AFTER OIL COOLER REPLACEMENT FOR OIL OIL TEMP SD(#PRI 2)ETOPS SIGNIFICANT SYSTEM. GROUNDED - YES. REMOVED AND REPLACED APU TCV, REF B737-900 AMM 49-91-21. OP CHECK GOOD NO LEAKS NOTED. REMOVED AND REPLACED APU LUBE MODULE, REF AMM 49-91-11. OP CHECK GOOD, NO LEAKS NOTED.