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 ECM (computer).
To test this situation, you must use an ohmmeter and test the sensor's resistance.
- Disconnect knock sensor harness connector.
- Check resistance between terminal 2 and ground. Resistance: 500 - 620 k ohms [at 25 °C (77 °F)] CAUTION: Do not use any knock sensors that have been dropped or physically damaged. Use only new ones.
