So I’m looking for some wisdom

2000 es300 3.0 170,000

Knock sensor code was thrown for 2, so I went ahead and replaced both (denso) and the harness.
reset codes, take it for a drive, did good for about 5 min then it threw the same code for knock sensor 2. Got back into it swapped the sensors locations (1 to 2 and 2 to 1)and put another new harness in (happened to have 2) reset the engine light, and it still throws sensor 2! So my next step of action is checking the harness plug to ecm with a volt meter, and see. If anyone has any input on this I would love to hear. Thank you

 

If you used genuine parts you have a wiring problem, or in rare cases a bad ECU. If you used non genuine sensors that is very likely your issue. When you say "Denso" are they actually Denso? Many fakes out there some are very convincing.

 

Hello,

Where did you get your sensor and the wiring? There is a ton of counterfeit parts around, especially on eBay or Amazon, not to say that even some OEM sensors straight from the dealership are bad from the factory.

The knock sensor circuit is pretty simple, there is only one wire leaving each bank, two of the other pins on the wiring are there for shielding. Below is the pinout of the ECU connector, Pin 27 is for Bank 1, Pin 28 is for Bank 2, check the resistance of the wire from the sensor to the ECU, also check if any of the wires got shorted on Ground, after that, check the shielding circuit. You can also try to bypass the sensor to see if the code will leave, if not, you may need a new ECU.



Hope this helps and best of luck!

 

Tested voltage through the ecu harness and everything is good. Thanks for the help. Going to order a new set of sensors and see how it goes from there.

 

Did you check the continuity of the wire?
What voltage did you measure? Knock sensors produce their own AC voltage, which usually doesn't go above 2V.

Those sensors are really not cheap to just throw them onto the car at random, though if you didn't buy them directly from the dealership, it is worth returning them and getting OEM ones (P/N: 89615-1209). Before getting new sensors, try bypassing a bad sensor, as it is described here, see if the ECU will accept it and erase the code, it will indicate that your ECU is fine, and the issue is either the wiring or the sensor; don't drive like that for long though, it is only a temporary measure. The only remark I would make is do not cut any wires, those connectors are pretty easy to de-pin, you just need to pry the cover on top of the connector a little bit and then use a needle to unlock and remove the pin, which should be more than enough for the test, here you can find more information about it.

Hope this helps and best of luck!