What was found
DIAGNOSTICS SHOWS #1 ENGINE VIBRATION DATA POINTS ARE ERRATIC. INDICATION SYSTEM ERRORS ARE SUSPECTED. GROUNDED - YES. COMPLETED ASA TSR713472 STEPS 1-4. REMOVED AND REPLACED MW0311 WIRE HARNESS. REF B737-900 AMM 73-21-06/401. REMOVED AND REPLACED FFCC VIBRATION SENSOR. REF AMM 77-31-04/401. FFCC VIBRATION SENSOR INSTALLATION TEST, MW0311 WIRE HARNESS INSTALLATION TEST AND ENGINE #1 RUN FOR FAULT CONFIRMATION REQUIRED. ACCOMPLISHED ALL REQ. ENG RUN AND OP CHECKS. ALL TEST PASS. REF AMM 73-21-06,36-11-03,77-31-00,73-21-00.