Detonation Sensor
The detonation sensor (knock sensor) is located in cylinder block. This sensor converts engine vibration (knock) into an electrical signal. This signal is processed by the Electronic Spark Control (ESC) igniter and relayed to ECU for determining amount of ignition timing retard. The ECU sends a signal to ESC igniter to modify ignition timing. Ignition timing is retarded only during period of knock.
CAUTION:
The detonation sensor is strong enough to with-stand engine vibration, but excessive impact with hammer, wrench, etc., can damage the sensor.