Knock Sensor: Description and Operation

Knock Sensor Circuit:

Purpose:
The Knock Sensor sends a signal to the PCM to retard ignition timing during a spark knock condition. When engine detonation stops and there is no knock signal being sent to the PCM, timing is advanced in small increments. This allows the PCM to maintain maximum timing advance under various engine load conditions.

Operation:
When abnormal engine vibrations (spark knock) are present, the sensors produce a voltage signal. These signals are received by the PCM via the Knock Sensor Module. The PCM fluxuates ignition timing to maximize performance and minimize spark knock.


Location:
The knock sensor is located in the lower side of the engine block.