System Description

The Knock Sensor (KS) system is used to detect engine detonation, allowing powertrain control module (PCM)/engine control module (ECM) to retard ignition control spark timing based on KS signal being received. The KS produces an AC signal so that under a no knock condition signal on KS circuit measures about .007 volt AC. The KS signals amplitude and frequency depend upon amount of knock being experienced. The PCM/ECM monitors KS signal and can diagnose KS sensor and Circuit.