Knock Sensor: Description and Operation

Knock Sensor:

PURPOSE
The Knock Sensor (KS) is a frequency amplifier. The sensor is designed to resonate at approximately the same frequency as the engine knock. This allows relatively large signals to be sent to the Electronic Control Assembly (ECA) without electrical amplification and with a relatively small sensor.

LOCATION
Mounted on the engine and used to sense engine detonation.

CONSTRUCTION
The sensor has a thin circular piezoelectric ceramic disk that is bonded to a metal diaphragm. Electrical connections are made through a two pin integral connector.

OPERATION
The ECA uses this information to alter ignition timing to optimize ignition timing while reducing the occurance of spark detonation.