DTC P0325: Knock Sensor Module Circuit: Description

The Knock Sensor (KS) produce an AC signal under all engine operating conditions. When the engine is running, the Powertrain Control Module (PCM) learns a minimum and maximum frequency of normal engine noise. The KS system monitors both knock sensors in order to determine if knock is present. If the KS system determines than excessive knock is present, the PCM retards the spark timing based on the signals from the KS. The PCM continues to retard timing until no knock is present. If the PCM malfunctions in a manner than will not allow proper diagnosis of the KS system this DTC will set.