ok so i have a bit of a problem... my knock sensor came with a wire that did not have the plug that connects to the plug on the main harness. dont ask me what happened to my previous knock sensor or plug... but i need to snip the plug on the harness, and crimp the wires together. only problem is that i dont know which wire goes where. Which one connects to which one? does the wire originating from the left side of the knock sensor go to the left side of the plug? or visa versa?


Modified by Ka24de240sxS13 at 10:40 PM 4/3/2008

Perhaps you've figured it out already, but one is ground and one is to your ECU. There's a gound spot on the head above and near your sensor, Check for continuity between that ground and your two wires to see which is which on the harness. Hopefully the sensor wires are different colors and you can tell which is the ground for that... If not, I haven't been much help and could check my ride for you... Lemme know.

k well my battery is out of my car, and i cant hook it up yet for a number of reasons, also the new wires i got are plain black, not labeled whatsoever. I would really appreciate it if you could look on your car...pics would be even more awsome. thanks dude

Okay, I'm on it. Gimme a few...

Okay, to start, here are the FSM diagrams for knock sensor but for my S14 (should be very close if not exact same as yours)

The line from the ECU is singular in appearance, but is shielded like co-ax, so the outside is ground and inside is hot... In the following pictures you can see how it looks like one black wrapped wire with two dirty white wires going into the first harness on the front of the block...The 'top' one is whiter and the bottom is yellowish-light grey. Top white being the ground...

From that little harness, the top white wire connects to the black wire (still ground) and the yellowish grey one goes to the yellow wire (hot)...

Finally you get to the actual sensor, Dang! how did you get in there!? Anyway, my camera could see it so... The yellow wire is connected to the bottom of the knock sensor and the top is not connected to my ground (did I mention I throw code P-0325?) Yeah, so I need to connect that I think but I have to double check... Anyway, here's a picture

I hope this helps. Even as I look at it, the confusion just grows. Maybe it just grounds to the block? I don't know why the black wire doesn't go to my sensor... But the yellow definitely goes to the lower of the two pins. Let me know what you find and if I actually helped.

Thats exactly what i needed man, thanks a lot. I really appreciate it. By the way, you should definately figure out why that wire isn't going all the way to your sensor, because there are two wires i would unplug the wire from the harness and the clip from the knock sensor and investigate.

and just double checking, the picture you took of the knock sensor is looking from the top right? i mean you didn't get under the car and look up at it. because if your looking from the bottom, that switches things up. thanks.

Oh, yeah, I'm supposed to be at work! So I ran out real quick, popped hood and took pictures all from leaning over my front bumper. Happen to have the FSM at the office for those boring lunch hours haha! Glad to help!

lol sweet thanks

Ka24de240sxS13 wrote:lol sweet thanks

Any update to this?

No updates. Issue regarding which wires go where is resolved. What do you need?

centralcoaster33 wrote:No updates. Issue regarding which wires go where is resolved. What do you need?

errr...I think our problems are waaaay different, now that look back over the thread and posts.

I have a wiring problem somewhere between my knock sensor and ECU...and I was wondering if the shielded wire would be a pain to re-wire. But I now see that yours was past the shielded wiring part.

Do you have a volt meter and can you see the FSM pictures in this thread? If so, I think you have all you need to diagnose your sensor and wiring. The shield or outside of the white coaxial wire is the ground (connects to the black wire of the sensor and then the engine grounds as shown disconnected in my car pictures) and the center is the positive (connectd to yellow wire of the sensor as shown in pictures of my car).

So in conclusion the ground of the knock sensor is the engine itself ansd the one wire going to the knock sensor is the hot wire?

Pretty close. The 'one' wire going to the sensor is specific to my car as the ground became detached (I don't know how and I still have to get around to re-attaching it). That 'one' wire is the yellow one pictured, is the positive (hot), connects to the center wire in the white co-axial (shielded) wire and to the ECU. The ground wire (again, not currently connected to my sensor as pictured) should be connected to the outer wire (shielding) of the white wire, which does go to the grounds on the engine block. Of course the engine is grounded to the battery so it doesn't really just stop there at the block. So really close to what you said, but there's more than 'one' wire as the ground is the second wire.

HAPPY BIRTHDAY CityHunt3R! Looks like you've been a member for 365 days!

I know this thread is old but i ran into a problem same as this. I've read the through the thread so the black wire, on the knock sensor harness, is grounded to the block. While the yellow one goes from the main engine harness, through the knock sensor harness, to the knock sensor itself, right??