Faulty knock sensor
Knock sensor circuit poor electrical connection
Knock sensor harness is open or shorted
Faulty Engine Control Module (ECM)
Engine Light ON (or Service Engine Soon Warning Light)
Possible Lack/Loss of Power
The knock sensor is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is sensed as vibrational pressure. This pressure is converted into a voltage signal and sent to the Engine Control Module (ECM).