Located in the engine block, the knock sensor retards ignition timing during a spark knock condition to allow the ECM to maintain maximum timing advance under most conditions.
- Connect a timing light to the vehicle and start the engine.
- Check that the timing is correct before testing knock sensor operation.
- If timing is correct, tap on the front of the engine block with a metal object while observing the timing to see if the timing retards.
- If the timing does not retard, the knock sensor may be defective.
REMOVAL & INSTALLATION
See Figures 1 and 2
- Disconnect the negative battery cable.
- Disengage the wiring harness connector from the knock sensor.
- Remove the knock sensor from the engine block.
- Apply a water base caulk to the knock sensor threads and install the sensor in the engine block.
- Engage the wiring harness connector.
- Connect the negative battery cable.