See Figure 1
The knock sensor is usually mounted to the right lower side of the engine block. When spark knock or pinging is present, the sensor produces a voltage signal which is sent to the PCM. The PCM will then retard the ignition timing based on these signals.
- Connect a timing light to the vehicle, then start the engine.
- Check that the timing is correct before testing the knock sensor operation.
- If the 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 Figure 2
- Disconnect the negative battery cable.
- Raise and properly support the vehicle.
- Disconnect the knock sensor wiring harness.
- Remove the knock sensor from the engine block.
- Installation is the reverse of removal. Tighten the sensor to 14 ft. lbs. (19 Nm).