Knock Sensor: Description and Operation

PURPOSE
The Knock Sensor (KS) supplies the Programmed Fuel Injection Electronic Control Module (PGM-FI ECM) with a signal indicating pre-ignition or detonation.

OPERATION
Mounted in the cylinder head, the KS reacts to the high frequency resonance that is created by pre-ignition or detonation in the combustion chamber and sends an electrical signal to the PGM-FI ECM. The PGM-FI ECM in turn modifies the spark advance to reduce or eliminate the "knock".