Knock Sensor: Testing and Inspection

KNOCK SENSOR (KS)
The knock sensor is attached to the cylinder block and senses engine knocking conditions. A knocking vibration from the cylinder block is applied as pressure to the piezoelectric element. This vibrational pressure is then converted into a voltage signal which is delivered as output. If engine knocking occurs, ignition timing is retarded to suppress it.




CIRCUIT DIAGRAM







HARNESS INSPECTION PROCEDURE




SENSOR INSPECTION
1. Disconnect the knock sensor connector.
2. Measure resistance between the terminal 2 and 3.

Standard value: about 5 M-ohms @ 20° C (68° F)

3. If the resistance is continual, replace the knock sensor.

Knock sensor torque: 16-28 Nm (11.8-18.4 ft.lbs.)

4. Measure the capacitance between the terminal 2 & 3.

Standard value: 800-1600 pF




P0326 - TROUBLESHOOTING PROCEDURES

HINT: When knock sensor signal is abnormally low.