Circuit Description

Knock Sensor (KS) system is used to detect engine detonation. PCM will retard spark timing based on signals from KS module. The KS produces an AC signal voltage that is sent to the KS module. The amount of AC voltage produced is proportional to the amount of knock.

When engine is operating, PCM will learn the minimum and maximum frequency of the noise the engine produces. When PCM determines that this frequency is less than or greater than the expected amount, DTC will set.