Oscilloscope Patterns and Waveforms

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

Spread the time on the horizontal axis, and confirm that the period of the wave is 132 microseconds (Normal mode vibration frequency of knock sensor: 7.6 KHz).:

HINT: If normal mode vibration frequency is not 7.6 KHz, the sensor is malfunctioning.