As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ACOMPLISHING ASA TASK CARD NG-36WC-00002-2 FOUND PRECOOLER VALVE ON ENG #2 TO BE UNSERVICEABLE. GROUNDED - YES. REMOVED PRECOOLER CONTROL VALVE REF B737-900 AMM 36-12-02-000-801. REPLACED PRECOOLER CONTROL VALVE REF AMM 36-12-02. OPS CHECK COMPLETED.