Supra Liftback L6-2997cc 3.0L DOHC MFI Twin-Turbo (1997)
Knock Sensor: Oscilloscope Patterns and Waveforms
Reference INSPECTION USING OSCILLOSCOPE
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With the engine racing (4,000 rpm) measure waveform between terminals KNK1, KNK2 of ECM and body ground.
HINT: The correct waveform is as shown.
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Spread the time on the horizontal axis and confirm that period of the wave is 123 m sec. (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.