General information
The knock sensor is a piezoelectric crystal. The knock sensor is installed on the cylinder block wall to detect detonation combustion of fuel in the engine cylinders. The vibration of the cylinder block caused by detonation is converted into a signal (voltage) proportional to its intensity. If detonation occurs in the engine, the electronic engine control unit, using this signal, reduces the ignition timing until it disappears.
Engines 2.0 l / 2.4 l. |
Engine 2.7 l. |
Troubleshooting Guide
The check engine light comes on or the tester displays the corresponding trouble code under the condition listed below.
1. If the knock sensor signal is not detected even when the engine is running under overload conditions.
2. If the knock sensor signal level is abnormally low.
Checking the sensor
1. Disconnect the knock sensor connector and measure the resistance between terminals "2" and "3" of the connector for the 2.7L engine or between terminals "1" and "2" of the connector for the 2.0L/2.4L engines.
- Nominal value (at 20°C): approximately 5 MOhm
Engine 2.7 l.
2. If the resistance is zero (the circuit is closed), replace the knock sensor.
- Tightening torque: 16-28 Nm
3. Measure the electrical capacitance of the sensor between terminals "2" and "3" of the connector for the 2.7L engine or between terminals "1" and "2" of the connector for the 2.0L / 2.4L engines.
- Nominal value: 800-1600 pF