Oscilloscope Patterns and Waveforms

Reference INSPECTION USING OSCILLOSCOPE
- With the engine racing (4,000 rpm) measure between terminals KNKR, KNKL of ECM and body ground.



- The correct waveform is as shown.



- Spread the time &n the horizontal axis, and confirm that period of the wave is 141 micro secs. (Normal mode vibration frequency of knock sensor: 7.1 KHz).

- If normal mode vibration frequency is not 7.1 KHz, the sensor is malfunctioning.