Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Knock Sensor: Service and Repair

1. Disconnect battery negative terminal before loosening or tightening the knock sensor.
2. Do not use any washers on the mounting bolt.
3. Knock sensor mounting bolt torque is critical and specifications must be strictly followed.
4. Check to see that the mounting bolt is clean and free of burrs that could affect torque values.
5. Check to see that the mounting boss on the engine block is free of dirt and excess paint that could prevent good contact with the knock sensor.


MOUNTING TORQUE 20 Nm (15 ft.lb.)

RESISTANCE infinite (open circuit)