Knock Sensor (KS)

Knock sensor is a piezoelectric crystal capable of converting vibration caused by engine knock (detonation) into voltage signals. Intensity of voltage signal is proportional to severity of knock. ECM modifies ignition timing to reduce knock. Engine knock is not a result of normal engine operation and should not be present on a properly functioning vehicle using quality fuel. Vehicle use 2 knock sensors (one for each side of engine).