I did a search but could not quite fit anything to my problem. I have a check engine light that comes on at almost exactly 3000RPM everytime, the code is "knock sensor signal - has not reached judgement in succession." I took a look through the starter removal panel in the pass. side fender well and the knock sensor wire has been spliced with one of those blue add a wire crimps (God only knows why you would want to) but I also noticed there was a wire mesh shielding that was wrapping the wire (factory) that was stripped away to put the conector on. I was wondering if anyone has had this problem and I have also heard the tin foil fix (wrapping the wire with tine foil)...does this wire need to be shielded to get a proper signal? Anyone know how to fix that wire or shield it properly seeing how it jumps right into the harness...Thanks!

Dan

 

I think the sheilding is supposed to be grounded. And yes it needs to be sheilded so that electrical fields do not interfere with the signal. Not sure if the tin foil trick work or not, somebody else can chime in. Why was the wire spliced? was it broken? That wire could be suspect as well, dunno, should be a low impedance type...thingy..

 

i just cut the wire and soldered a wire and never had a problem......

 

man, i had the same exact problem you are having.

my mechanic told me to go to radio shack and get some coaxial cable (shielded wire). he cut the knock sensor wire and spliced in the coaxial and problem fixed. my truck runs a ton better after that!!!

it definitely needs to be shielded wire though!!

 

I have no idea why it was spliced, for what reason you would want that signal...that was the electrical expertise of the former owner. And yes according to the wiring diagram the shield is grounded I found out.

I'll stop in radio shack tomorrow and see what they have as far as shielding or shielded wire goes...grounding may be interesting tough, hopefully that is the issue and I don't have a bad knock sensor.

Thanks for the info!

 

yes, as several have posted already, the knock sensor wire has to be sheilded. rg-58 multistrand works best from what i've found, but the multi-strand is difficult to find around my area.

it's shielded to prevent any electrical interferance from disrupting the signal. should the sheilding be compromised, the sensor be dead, or the wire be shorted to ground (or the sheilding touching the signal wire), you will experience bad gas mileage, and a lack of power overall.

on mk3 supras, if the KS code is registered, the ECU will enrichen the fuel mixture, and retard the timing in a safety effort to prevent detonation/preignition. i'm not sure if our trucks work the same way, but the power difference between having the KS code (52 on the supra) and fixing it was like night and day!

-shaeff

 

I'm getting the 52 code as well and my truck runs like crap it wouldn't pull a greasy string outta rats @zz. I've checked the pigtail and spliced new wires in and still no help. Does anyone know how to test the sensor before i tear into the top half of the motor to get to it? Or any other tricks or tips would greatly be appreciated. It's on a 92 pickup truck with a 3vz-e.