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DIY Repair, Fault Code P0325, 2004 Honda Accord

Car: 2004 Honda Accord EX Sedan 2.4L

Getting a fault code P0325 (Knock Sensor Circuit Malfunction). I plan to DIY repair.

How can I test the sensor itself? I know I can check harness resistance for an open/short, but wanted to know if there was a way to check the sensor itself. Before I make a purchase, I would like to know if I only need a sensor, a harness or both. Also, any tips from those that have had experience with this issue, please feel free to offer suggestions/advice. Thanks.

Try this;

And tricks to remove it;

Hope that helps

Another method to test the sensor if you have a timing light is, make several marks on the crank pulley with a piece of chalk.

Start the engine and while it’s idling point the timing light at the pulley. Now take something and rap on the engine next to the sensor.

If the sensor is good, the marks you made will change position.

If the marks don’t move, more than likely it’s the sensor.


Good advice above, definitely the place to start. The knock sensor produces a small voltage when it gets vibrated. The bigger the vibration, the bigger the voltage It doesn’t need a battery to work, it produces the voltage itself from the energy of the vibration. The voltage also varies w/ time in different ways depending on the nature of the vibration motion. Be aware that it is possible for a faulty sensor to still respond with a measured voltage output when you whack it. It might just not produce the correct voltage is all, too high, or too low, or vary the wrong way w/time compared to the spec the ECM is expecting. So to have a reasonable chance to successfully test one on the bench you really need to have a known good one to compare it to.