Inspection Using Oscilloscope

PROCEDURE





With the engine racing (4,000 rpm) measure between terminals KNK1, KNK2 of Engine Control Module and body ground. The correct waveform appears as shown in the illustration on top. Spread the time on the horizontal axis (bottom illustration), and confirm that period of the wave is 123 micro seconds (Normal mode vibration frequency of knock sensor: 8.1 KHz). If normal mode vibration frequency is not 8.1 KHz, the sensor is malfunctioning.