What was found
IN AN ETOPS FLIGHT SEGMENT THE LEFT ENGINE FILTER BYPASS LIGHT BLINKED THEN CAME ON STEADY. THE ENGINE WAS SHUT DOWN AND THE FLIGHT DIVERTED TO TER. THE MAIN OIL SCREEN AND CHIP DETECTORS WERE CLEAN. PLACARD THE FILTER BYPASS LIGHT INOPERATIVE PER MEL AND THE FLIGHT CONTINUED. CHECK-C 8-25-99 LAX. *S/D* THE OIL FILTER DIFFERENTIAL PRESSURE SWITCH WAS REPLACED TO CORRECT THE MALFUNCTION.