FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Enhanced Testing



P0325 - Knock Sensor Circuit






General Description
Knocking is a phenomenon characterized by undesirable vibration and noise and can cause engine damage. The knock sensor (KS) is attached to the cylinder block and senses engine knocking. A knocking vibration from the cylinder block is applied as pressure to the piezoelectric element. The knocksensor (KS) detects vibration upon increase and decrease in engine RPM and generates a voltage based on this vibration. The ECM controls the ignition timing based on the amplitude and frequency of the knock sensor signal. For example, if engine knocking occurs, the ignition timing is retarded to suppress it.

DTC Description
If there is rarely change compared with previous knock sensor's signal, the ECM determines that a fault exists.

Detecting Condition





Wiring Schematic