Knock Sensor: Description and Operation

LOCATION

Sensor mounted in engine block.

PURPOSE

Sensor informs Powertrain Control Module (PCM) detonation has occurred.

PCM retards timing until detonation is no longer detected.

Knock Sensor Operation:

OPERATION

Sensor generates a signal when spark knock, (pre-ignition, detonation, or pinging) occurs in combustion chamber, (due to vibration of the piezo electric crystal).