Diagnostic Procedure

HINT: If diagnostic trouble code 52 is displayed, check No. 1 knock sensor (for front side) circuit. If diagnostic trouble code 53 is displayed, replace engine control module. If diagnostic trouble code 55 is displayed, check No. 2 knock sensor (for rear side) circuit.













DIAGNOSTIC PROCEDURE




INSPECTION USING OSCILLOSCOPE
With the engine racing (4,000 rpm) measure waveform between terminals KNK1, KNK2 of engine control module and body ground.

HINT: The correct waveform is as shown.




Spread the time on the horizontal axis, and confirm that the period of the wave is 123 micro 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.