The knock sensor threads into the side of the cylinder block below the intake manifold. When the knock sensor detects a knock in one of the cylinders, it sends an input signal to the PCM. In response, the PCM retards ignition timing for all cylinders by a scheduled amount.
Knock sensors contain a piezoelectric material which constantly detects engine knock vibration and sends an input voltage (signal) to the PCM while the engine operates. As the intensity of the engine knock increases, the knock sensor output voltage also increases.
Last modified on 2008-11-11 17:51:35