Knock Sensor: Description and Operation

Knock Sensor:

PURPOSE
The knock sensors (2) records engine vibrations (detonation), and signals the ECU, so that correct timing configurations can be set.

LOCATION
The sensors are mounted under the intake manifold. One sensor is mounted on each engine case half.

OPERATION
The sensors generate a signal whenever a vibration is sensed. When a knock occurs, the piezo-electric crystal (piezo element) in the sensor is compressed by the weight above it. The squeezing of the crystal, generates a low voltage signal readable by the ECU.