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Home >> Chevrolet >> 2003 >> Avalanche 2500, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self Diagnostics - 8.1L >> Diagnostic Tests >> DTC P0325: Knock Sensor Module Circuit >> Description

DTC P0325: Knock Sensor Module Circuit: Description

The Knock Sensor (KS) produce an AC signal when specific frequencies are detected. When the engine operates, the Powertrain Control Module (PCM) learns a minimum and maximum frequency of noise of normal engine operation. The KS system monitors both KS in order to determine if knock is present. If the KS system determines that excessive knock is present, the PCM retards the spark timing based on the signals from the KS system. The PCM then retards timing until no knock is present.