Circuit Description

The Knock Sensor (KS) System enables the powertrain control module (PCM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The knock sensor is located on the intake side of the engine block. The sensor produces an AC voltage signal that varies at all engine speeds and loads. The PCM adjusts the spark timing based on the amplitude and the frequency of the KS signal. The PCM receives the KS signal through 2 isolated signal circuits. If the PCM is operating on large amounts of spark retard and is unable to eliminate the knock, this DTC will set.