The operation of the Knock Sensor (KS) is to monitor preignition or "engine knock" and send the signal to the PCM. The PCM responds by adjusting ignition timing until the "knocks" stop. The sensor works by generating a signal produced by the frequency of the knock as recorded by the piezoelectric ceramic disc inside the KS. The disc absorbs the shock waves from the knocks and exerts a pressure on the metal diaphragm inside the KS. This compresses the crystals inside the disc and the disc generates a voltage signal proportional to the frequency of the knocks ranging from zero to 1 volt.
There is real no test for this sensor, the sensor produces it's own signal based on information gathered while the engine is running. The sensors also are usually inaccessible without major component removal. The sensors can be monitored with an appropriate scan tool using a data display or other data stream information. Follow the instructions included with the scan tool for information on accessing the data. The only test available is to test the continuity of the harness from the PCM to the sensor.
REMOVAL & INSTALLATION
On Integra models, the sensor is most easily accessed from underneath the vehicle.
- Disconnect the negative battery cable.
- Drain the engine coolant into a suitable container.
- If working on an Integra, raise and safely support the vehicle securely on jackstands .
- Unplug the sensor connector.
- Using the proper size socket, loosen and remove the knock sensor.
- Carefully thread the sensor into the engine block.
- Tighten the sensor.
- Attach the sensor connector.
- Lower the vehicle.
- Refill the engine coolant.
- Connect the negative battery cable.