whoopy

i was wondering if someone (with experience) can explain the function of the knock sensor harness...i dont understand the purpose of the one wire surrounding the other.... noise perhaps..??
i ask because i have either a bad connection at tthe sensor, or someting is up with the harness....
if it is the harness, anyone have suggestions on how to fix.. if possible..

thanks again.

Matt93SE

iTrader: (44)

you're correct. there's only one wire that actually attaches to the knock sensor. the other is a shield around that one to prevent noise getting into the wire.

they do the same thing with RCA cables and microphone cables, and any other place where you hear of a coaxial cable or shielded wire/cable...

so when you're checking the knock sensor, check the resistance of each wire against the engine block, NOT against each other. the shield isn't connected to anything past the harness connector at the side of the engine.

MISTER BIG

so to clarify,
to check the harness, i check the resistance of each wire coming out of the harness when its plugged to the sensor ?
i have to fix this problem tommorow at my parents place, so i need to know everything in order to fix it...
by the way, do you know the torque value for the knock sensor bolt ?
and ill take any tips or advice in doing this repair..
thanks matt

Matt93SE

iTrader: (44)

I need to know which engine you have as well. VG and VE are very different in sensor type and placement.
(ve are the same as the 4th gen in type and placement).

but to test them, check each wire's resistance against the engine block. one wire will be open circuit- that's the sheild wire.. the other wire should read ~500k ohms. (FSM says "continuity should exist"). it will vary slightly with temperature and the condition of the knock sensor. if you get open circuit on both wires, then the knock sensor is bad.

MISTER BIG

okay, i guess i forgot to mention...but the sensor is brand new..
so what your saying is ..if i get the correct sensor reading through the harness, then my harness is good ?
because all of a sudden ..i was getting no reading at the end of the sensor harness...so i think the harness came loose at the sensor..
but, have you ever heard of the harness causing problems ?? if so, how can you repait them.. ??

MISTER BIG

oops, sorry.. its VE for the bolt torque..
do you think the torque would effect the reading from the sensor ??

Matt93SE

iTrader: (44)

repair? maybe.. best just to replace them. they're around $20 for a new one from the dealer....

sounds to me like it may have become disconnected...

MISTER BIG

here in Canada, they are telling me you can only get the two harness's, the one i need, and the one that travels over the engine with the Fuel injector harness... i think its bull, but i called two different nissan dealers..

i think ill have to get on them if i do need a harness...

Matt93SE

iTrader: (44)

ummm, so what are you trying to say?

they can get you the harness you need, but that's not good enough?

MISTER BIG

they said, i have to buy both...they dont sell as one.... what did i tell'yah.. its bull..im gonna have to go in and look at their micro-fiche

Jeff92se

iTrader: (82)

Well honestly. Considering what a huge pain it is to remove the ks, I'd definately just buy both. You will note when you take off the original one, the connectors will be all corroded. When you see the new ks/harness, they blob some dielectric grease all over the connectors to prevent it.

MISTER BIG

yeh i know, thats my mind-set right now,,,,since i was just in their 3 months ago replacing the knocksensor, along with the exhaust manifold bolts....
does anyone know the part number. (i know.. a long shot...but these dealers are ****ing me off... they make you go in to SHOW them exactly what you need)

anyone know the knock sensor bolt torque ??
thanks

Matt93SE

iTrader: (44)

no.. they're full of crap. I ordered the one I need just the other day..
knock sensor harness part number is 24079-96E00 if you have a VE.
I paid #20.xx for it from Courtesy and got it in the mail yesterday.


the VG one is different, but I know it's a short section that can be purchased separately as well, since I've swapped two VGs and left them dangling on the engine during the swap.

Jeff92se

iTrader: (82)

http://www.4dsc.com/articles/drivetr...k_sensor.shtml

MISTER BIG

WHICH PART NUMBER IS RIGHT GUYS...
this is from the 4DSC.com site >>> -Knock sensor sub harness PN 24078-30P00

Matt93SE

iTrader: (44)

CALL A DEALER. that article is two years old. the part I got I ordered on Monday..

The one in the article is also the sub-harness. that may be another small part that I know nissan stuck in there as an afterthought to cure some issues with the KS falsing...

MISTER BIG

i didnt mean to write in caps..i just turned it off when i realized...
i just got a fax of the micro-fiche... its cool now..

so is their a torque in the FSM for the sensor ??

Matt93SE

iTrader: (44)

read the article above.

MISTER BIG

yeh i did.
he said he didnt see one... thats why i asked if you guys have ? your the pros around here.. i figure you would know.

Matt93SE

iTrader: (44)

Ken Rosengren wrote that article. I consider him an equal. I'd take his word for it even rebuilding my own engine.