40series

is there a way to test knock sensors . i replaced one and the code p0327 came back i know i replaced one they are 75 a piece. the harness was new too . i should'nt have to replace the harness unless its pinched , and how do you check for a bad harness?

andrew383

iTrader: (14)

So you have 2 new sensors and a new harness now???

40series

i have one , new sensor, i put a new harness on and didnt know whether to replace the harness, again the sensors are like 75 harness 50 $

MikeGyver

iTrader: (5)

https://www.performancetrucks.net/fo...d.php?t=474720

oldred95

Knock sensors have a piezo electric crystal(s) inside them that when shocked produce a voltage. I don't recall whether its DC or AC, I want to say its AC voltage roughly in the 0-1 volt range when you strike the valley cover near the sensor. You can ohm them but I find it best to actually smack the block and check to see that the sensor is producing a voltage signal that way you know that it does infact work. One thing I do know is that if the sensor has been dropped at any point in its life it can very easily ruin it and all you can do is get another. This is why everytime I do a knock sensor job I make damn sure to test each knock sensor before putting the intake back on.