Symptoms

- Engine Light ON (or Service Engine Soon Warning Light) - Lack/Loss of Power

Possible Causes

- Knock sensor circuit short to ground - Knock sensor circuit short to power - Knock sensor circuit open - Faulty knock sensor - Faulty Engine Control Module (ECM)

When Detected

An excessively high voltage from the sensor is sent to Electronic Control Module (ECM)

Tech Notes

Replacing the knock sensor usually takes care of the problem.

Description

The knock sensor is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is sensed as vibrational pressure. This pressure is converted into a voltage signal and sent to the Engine Control Module (ECM).