Oscilloscope Patterns and Waveforms

- With the engine racing (4,000 rpm) measure between terminal KNK of ECM and body ground. The correct waveform is as shown.





- Spread the time on the horizontal axis, and confirm that period of the wave is 132 micro secs. (Normal mode vibration frequency of knock sensor: 7.6 KHz.)
- If normal mode vibration frequency is not 7.6 KHz, the sensor is malfunctioning.