so, I'm looking to wire up the knock sensor using the factory wire, but I can't determine which one it is on the factory harness. the knock sensor wire on the plug is white, but the only white wire I have is a thicker copper wire and the knock sensor wire only has 1 small wire in it. any help?

got a meter? ohm it out.

unhook the harness. put one lead on the known pin, i think 21 or 23.

then start touching it to the pins that you think could be it. when you hear the beep you found it.

if you dont have a meter, go buy one, it will become a great friend if you enjoy working on cars.

the knock sensor wire is pin 23. It's a white wire. probably the easiest thing to do is find pin 23 on the big blue ecu connector and cut about 6 in. from the blue ecu connector and slice a shielded wire from there all the way to the knock sensor. Well that's what I did and it works fine.

it still does not make sense to m why everyone does this.

cut a wire that already runs where you need it, just to run your own.

does anyone else realize how dumb that is?

Its because it does not already run to where its needed, the knock sensor is in the starter harness in a ka24de or not even in any chassis with the ka24e. I dont know why Nissan engineers chose to route through a body harness to get an engine sensor, or put an ABS sensor into the engine harness. I'd have kept the engine stuff with the ECU harness and the body stuff with the body harness... but that would make too much sense.

FOR THE LOVE OF GOD.

ITS IN THE CA ENGINE HARNESS!!!!!!

NOT THE BODY HARNESS. IT RUNS FROM THE ECU, THROUGH THE FIREWALL, AND THEN TO THE PLUGS BY THE BATTERY.

YOU KNOW, THE PLUGS YOU CUT OFF AND SPLICE WITH THE KA PLUGS? YEAH, ITS RIGHT THERE. RUN A WIRE FROM THERE TO THE KNOCK SENSOR.

I GUESS I GOTTA DO A RIGHT UP WITH PICS, CAUSE NOT MANY PEOPLE CAN SEEM TO GRASP THE CONCEPT.

THIS IS MY NEW MISSION IN LIFE.

ARGH.

Ca18datsun510 is exactly correct. The wires run all the way down to the plugs you hafta splice anyways, so no need to run wires all the way back to the ecu. Here's a copy of a knock sensor write-up I did for someone on 240sxforums.com hope this helps a bit.

first is the brown wire for the 02 sensor. Just splice the brown wire from the CA harness into this wire from the KA plug.

Here's a pic of the knock sensor location under the intake manifold.

A pics of what the knock sensor plug looks like. once again use shielded wire for the knock sensor.

Pic of a shielded wire with the outer layer of insulation removed. The shielded portion is actual made up of a bunch of little wires that are wrap around rubber insulation below it.

Here's a pic of the what wire looks like on the inside. Under the white insulation is the actual wire itself. basically it made up of 4 layers. Outer insulation, shield, inner insulation, and the actual wire.

Please dont pay any attention to the plug itself. I took this pic before I cut the plug off and spliced in the KA plugs. This is the white wire you need to wire the knock sensor to.

Once again pay no attention to the plug pictured. Splice the shielded portion of the knock sensor wire to this black wire. The shield portion stops just a bit before it gets to the knock sensor plug.

A little ways down the line closer to the ecu the black and white wires from the last 2 pics gets spliced back into a shielded wire and then split up again into 2 wires right before they go into the ecu. The white on goes to ecu pin 23, and the black one goes to a pin on the ecu too but I cant remember which pin. The black is just a ground so you should be fine.

But heres a better pic. I stripped down the shielded wire a little better for you to see. the shield portion of the wire can be twisted off the inner insulation like shown in the pic. you can get shielded wire from home depot or just take some off your KA harness. When you extend your o2 sensor and maf plug your gonna need some more shielded wire as well.

oh and please excuse my ****ty *** microsoft paint skills or lack of.

Sorry If this was a bit longwinded but trying to make sure you get your ca running right. Let us know how it turns out. Hope this helps out a bit.

Wei

thank you, i love you!

i havent had a stock ca harness around for a while, so i couldnt get pics.

can we add that to the faq pls???

thanks for the info, I did what CA18 said and found that the wire I was looking at was right, now I just need to find some shielded wire somewhere, I don't have my KA lying around anymore to hack some off of.

Hey anumeric thanks for the write up. But there is one thing i don't understand, If i have already wired my brown O2 wire on the CA harness to a power source, what would wiring the brown KA wire to this do? Also what does this have to do with the knock sensor?

Thanks

ttvines wrote:Hey anumeric thanks for the write up. But there is one thing i don't understand, If i have already wired my brown O2 wire on the CA harness to a power source, what would wiring the brown KA wire to this do? Also what does this have to do with the knock sensor?

Thanks

No prob. If you already have your o2 sensor "ca brown wire" wired to a switched power source then your fine. I just including it in the write up to make it easier for some people. Every wiring guide that I have came across online only says switchable source and no specifics. It doesn't have anything to do with the knock sensor wiring, I just copied and pasted everything and forgot that the o2 stuff was still there. lol

Wei

It's stickied now!

This may be a stupid question, but the knock sensor that people are using is which one or what part number? Everytime I search for one, there is only a generic Nissan knock sensor listed that goes for S13 and S14 SR/KA, Z32, B15, etc. I just want to make sure that I am not going crazy. The reason I am asking, is because the only alternative I have to the crappy mechanics here in Naples, It, is the Nissan Dealership (extreemly overpriced, but outstanding work) or odering parts online and doing the work at the auto hobby shop. I just don't want to be stuck w/ parts that I cannot use. Thanks