Description & Operation: Description: Notes

The knock sensor is mounted on the side of the cylinder block one each, and it detects vibrations in the event of a knock and transmits them to the ECM. The sensor uses piezoelectric ceramics to generate voltages higher than the reference voltage when vibration or pressure is applied to the ceramic element from outside and is passed to the ECM.

When a knock occurs, the sensor produces voltage signal. The ECM retards the ignition timing when knocking occurs. If the knocking disappears after retarding the ignition timing, the ECM will advance the ignition timing. This sequential control can improve engine power, torque and fuel economy.