Knock Sensor: Description and Operation

Knock Sensor





The knock sensor incorporates a piezoelectric element and is mounted on the engine block between cylinders 2 and 3. The piezoelectric element in the sensor converts vibration in the engine block into a voltage.

This sensor is connected to control module pin 11 and grounded via pin 30.

The control module evaluates the sensor voltage after a cylinder has fired. If the amplitude exceeds a certain limit it is assumed that knocking has occurred and the ignition will be retarded. If retarding the ignition does not eliminate the knocking, boost pressure will also be reduced.