- Be sure the ignition switch is OFF.
- Disconnect the sensor electrical connector. Connect an ohmmeter.
- Measure the resistance between terminals 1 and 2 (component side). Specification should be 5mohm at 68 degrees F.
- Replace the sensor, as required.
- To check the output signal, remove the sensor from its mounting.
- Mount the sensor in the jaws of a bench vise.
- Connect a voltmeter between terminal 1 and 2.
- Wrap the bench vise sharply with a hammer and note the voltmeter reading.
- Verify that the voltage spike is less than 1 volt.
- If no voltage spike is observed, replace the sensor.
The knock sensor is used to detect engine vibrations caused by preignition or detonation and provides information to the ECM, which then retards the timing to eliminate detonation.
Removal & Installation
- Disconnect the negative battery cable.
- Remove the intake manifold support bracket.
- Disconnect the sensor connector.
- Remove the sensor from its mounting.
- Installation is the reverse of the removal procedure.