Oscilloscope Patterns and Waveforms

INSPECTION USING OSCILLOSCOPE

Knock Sensor Signal Waveform:

- Top waveform: With the engine racing (4,000 rpm) measure between terminal KNK of ECM and body ground.

- Bottom waveform: Spread the time on the horizontal axis, and confirm that period of the wave is 123 microseconds
(Normal mode vibration frequency of knock sensor: 8.1 KHz.)

HINT: If normal mode vibration frequency is not 8.1 KHz, the sensor is malfunctioning.