DTC P0325: Knock Sensor Module Circuit: Description

The Knock Sensor (KS) produces an AC voltage at all engine speeds and loads. Depending on the amplitude and frequency of the KS signal, the Powertrain Control Module (PCM) will adjust the spark timing. The PCM uses the KS signal in order to calculate the average voltage. The PCM inspects the KS and the related wiring by comparing the actual knock signal to the assigned voltage range. If the KS system is operating correctly, the PCM should monitor the KS voltage that is varying above and below a predetermined average voltage. This DTC will set if the PCM malfunctions in a manner that will not allow proper diagnosis of the KS system.