DTC P0327: Knock Sensor Circuit: Description

Powertrain Control Module (PCM) uses a knock sensor to detect engine detonation, or spark knock. Knock sensor produces an AC signal at all engine speeds and loads. The PCM makes adjustments to spark timing based on the amplitude and frequency of knock sensor signal. The PCM uses knock sensor signal to calculate the average voltage. Then, PCM assigns a voltage value. The PCM checks knock sensor and related wiring by comparing the actual knock signal to the assigned voltage range. A normal knock sensor signal should stay outside the assigned voltage range. Diagnostic Trouble Code (DTC) will set if PCM detects a knock sensor signal of less than .4 volt.