Knock Sensor: Description and Operation

PURPOSE:
The knock sensor is used to detect engine detonation (ping). The ECM will retard the electronic spark timing based on the signal received.

OPERATION:
The knock sensor detects abnormal vibration in the engine. Then, the knock sensor produces an AC signal which increases with the severity of the knock. The ECM reads this signal and retards the timing until the knock is stopped.

LOCATION:
Engine block near the cylinders.