Circuit Description

The Knock Sensor (KS) system enables the Engine Control Module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The Knock Sensor (KS) is located on the intake side of the engine block. The KS produces an AC voltage signal that varies depending on the vibration level during engine operation. The ECM adjusts the spark timing based on the amplitude and frequency of the KS signal. The ECM receives the KS signal through a signal circuit. The KS ground is supplied by the ECM through a low reference circuit. The ECM uses the KS signal to calculate the average voltage and then assigns a voltage range value. The ECM should monitor a normal KS signal within the voltage range. If the ECM detects the KS signal outside of the voltage range, or the KS signal is not present, this DTC sets.