S/C Knock Sensor New Relocation Location

TwoBills said:

After all this, I still don't see how a relocated KS is any different than a resistor bypass. All a KS is is a piezo sensor w/a 500K ohm end of line resistor. It's either normally open, with a resistor in parallel, or normally closed, with a resistor in series (not sure which). In normal condition (no knocking) the computer sees the 500K resistor. In a knocking condition the computer sees either an open circuit or a dead short, which retards the timing advance. That's all it does.
I'm still setting po328, have been for years now. Thinking I had a ks related problem I installed a boost/vacuum guage, but after I did I saw a loss of vacuum after the truck warmed up, along with a loss of boost. Found the bypass actuator valve was leaking. Took care of this by canning the valve and installing a manual boost actuator in its place. Still setting the ks code, but no more boost problems. Always 8 lbs.

If I care to I can light up my Firehawks and chirp 2nd and 3rd (my 5 speed's too rare and the tires cost too much for that). If I drive accordingly I can get 18mpg, but I like my boost lever too much so I'll live w/14.5. Been like that since day one. '01 sc cc 2wd 5sp 165K.

Maybe Ill try the resistor in the Spring.

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massbaster said:

from what i have experienced is that the resistor works. my truck ran great with the 2 resistors wired in place of the ks. only trouble was i wasnt sending the required 2.5v to the computer and was still getting a hard trouble code causing engine light to be on. aside from that preventing me from obtaining a sticker, the truck ran great.

unfortunately here in mass, i cant run without a valid inspection sticker so until you replace the sensor, the resistors work, but throw a code that will prevent me from passing inspection here.

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Q451990 said:

On the 1990 Infiniti Q45 one member of another forum tried using a resistor to simulate the KS until he got around to pulling the plenum and replacing his cracked ones. The result was that the ECU code was eliminated - but that the ECU timing maps were still different than they are with a properly functioning ECU. This guy is intimately familiar with the correct timing target at a given RPM because he has unlimited access to a Consult. His conclusion was that the ECU must be monitoring the frequency pattern from the KS and was not receiving the correct input - and then trying to protect the engine.

I have no idea if the Frontier's ECU behaves the same way, but if I had to guess, I would think so. The OBD-II ECU should be at least as "smart" as the Q's OBD-I ECU that was designed over 20 years ago.

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massbaster said:

from what i have experienced is that the resistor works. my truck ran great with the 2 resistors wired in place of the ks. only trouble was i wasnt sending the required 2.5v to the computer and was still getting a hard trouble code causing engine light to be on. aside from that preventing me from obtaining a sticker, the truck ran great.

What was the "hard trouble code"? The knock sensor won't set the light. The 2.5v is the result of the 500K (540K?) resistor stepping the voltage down. Are you sure you have the right resistance?

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pcar993 said:

Something is not right... I have done the resistor mod and no check engine light for me. What 2.5v are you referring?



basically, took the thicker wire and cut it. then wire nutted the end to one 100k resistor. connected that to 470k resistor with nut and then connected the final end to piece of wire and bolted it to engine. same bolt as the KS used. i could not connect it to the plug as the KS was an open and no longer grounded. testing like this produced 0volts for me. unless i was really spaced that day and forgot how to run the multimeter i am pretty sure i got it right.
but mistakes can and do happen

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ropetob said:

First, Massbaster, how is the new relocation spot on the engine block working out for you? Have you had any problems? How’s your power?

Second, I just did the relocate to my firewall per GothamEMS instructions. However, I’m still getting a KS code. So I figure either:

1) The ground is bad

2) The sensor is bad

3) I wired something incorrectly or did a poor job splicing/soldering everything together

I tried to follow the wires to the original KS, but it was a PITA. So, rather than ripping the wire out of the original KS like GothamEMS did, I cut the wires at the green plug to the left of the S/C per daggerdoggie’s instructions on Nexterra.org because it was just easier. As a result, I had to kinda merge the 2 instructions together to make it work since he didn’t use the Maxima harness, and he relocated to the S/C rather than the firewall.

So, rather than there being one coax type wire, there were two wires at the green plug, one white-ish with copper wire and one yellow-ish with silver wire. I assumed that the white/copper wire was the middle of the coax, and the yellow/silver wire was the bare ground wire. So, I connected the copper wire to the clear copper wire on the harness and the silver wire to the white silver wire on the harness. Does this sound right? Would the gauge of wire I used to go from the plug to the harness matter (harness was too short from that spot)?

Here are the parts that I used.

KS:
RockAuto Auto Parts
Nissan>1999>Maxima>Emission>Knock (Detonation) Sensor>
ORIGINAL ENGINE MANAGEMENT Part # KS24 {#2206030P00, F3XA12A699AA, F3XY12A699A}

Harness:
HARNESS AS :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com
Product SKU: 24079-31U01

The sensor that a lot of people were referring to on rockauto was discontinued, but there were several listed for the 99 Maxima. So, I bought the one that said it was OEM.

Does anyone see anything inherently wrong with what I described above? I haven’t had a chance to check ground/voltage/continuity/etc., but just wanted to get this out there and see if anyone can help.

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JLAUBACH said:

I'v got a 2004 3.3sc frontier it cranks but no start but has fuel,spark,air and changed ecm relay,crankshaft position sensor,rotor,cap.what happened was driving on hwy running great and just stalled at 70mph and has'nt started since???HELP PLEASE

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massbaster said:

pics

How is this location working long term? I used the firewall, working decent! A lot better than failsafe mode! I want to try your method but curious if it worked 100% or not..

here ya go
hope these are good enuff, only have cell phone to use,

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