Knock Sensor: Notes

The knock sensor is a piezoelectric device attached to the cylinder block that senses pressure from engine knock conditions. This vibrational pressure is then converted into a voltage signal which is delivered as output. If engine knock occurs, ignition timing is retarded to suppress it.

Fig 1: Locating Knock Sensors

Courtesy of HYUNDAI MOTOR CO.

[CIRCUIT DIAGRAM (KNOCK SENSOR)] 

Fig 2: Knock Sensor Circuit Diagram

Courtesy of HYUNDAI MOTOR CO.

[HARNESS CONNECTOR] 

Fig 3: Identifying Knock Sensor Harness Connector

Courtesy of HYUNDAI MOTOR CO.