I just found the wire that goes to the knock sensor to the ecm and was trying to desensitize the knock sensor.....it said cut the wire and measure the resistance from the cut to the knock sensor....well it's not reading anything.....does that mean that the sensor is bad or what? Thanks in advance guys.

Michael

 

from the cut to the knock sensor? are you reading it as
x = where ur DMM leads are

x-knock sensor -----------x
or

-knock sensor-x----------x

(ps Im not sure how a Knock sensor is actually wired up so Im just going by what you say)

if you're doing the bottom one, I'd think it'd be almost zero as you're measuring the resistance of that piece of wire. dont think I see an LT4 knock sensor in your list of mods. why not just get 1 of those??

 

i've got a lt4 km but it didn't help......that's why i'm doing this. i'm just trying to figure this diagram out......http://www.geocities.com/MotorCity/6647/ta93/knock.htm what is it measuring after u cut the wire.....

 

okay, from what that diagram and such say
x= dmm leads

gnd-x----knock sensor-----x (cut) ----- ECU

one lead should be at ground and the other at the cut

 

im reading res. through the circuit.....

knock-----------x x------------ECU


measuring from x1 through a volt Ohm meter to x2

 

theres only one wire from the knock sensor....

Where is the ground?

 

pick a place where a ground wire is attached to your frame, i would think that would be a sufficient ground

 

the diagram from what im lookiing at should look like this......




knock sensor-----------------------Ecu




the digram makes it look like the sensor is in-line

 

One meter lead to ground, the other to the cut wire leading to the knock sensor. Read resistance.

 

i tested from the knock sensor to the cut there is no connection.......do you think that the knock sensor is bad?

i did test from the ECU to my ground and got 23.29ohms but im guessing thats just reading through the ECU which is mounted to the body.......

I would guess that the sensor is bad but if im wrong please let me know.

 

Imm a bit confused, the 1 wire thats coming from the Knock sensor, the one thats cut. did you put a lead there and the other lead to the ground? obdII knock sensors are supposed to be around 100K ohms, if i remember correctly.

 

yes thats what i did but there was no resistance between the ground and the wire leading from the knock sensor......there was no connection......so i tested the ECU side of the cut wire and got the 23.29Ohms.

Thats how i came to the conclusion that the sensor was bad

 

Then, go under the car, remove the connector to the knock sensor, put one meter lead on the terminal of the knock sensor, the other meter lead on the metal body of the knock sensor and measure resistance. If there is none, your sensor is open

 

It must be open because it's not reading anything.....What does that mean that it's open?

 

I just tested the sensor and it is showing to be an open circut......im guessing that something has separated inside the sensor itself......

How would the bad sensor effect horsepower?


-brian