Sorry, I know this has been covered a number of times and I've followed all the DIY's on the hair net, but I'm not getting very far, I've done the ohm test and get nowt in both directions, I've done the mega ohm resistor with 3 different ones just in case and everyone I clear down the error code it comes back.

 

I've just looked at the wiring diagram and pin 23 from the ecu goes to the knock sensor, the diagram shows it as white but I think it's a dull yellow?

 

On the diagram it shows a dotted line around it which I assume is a sheild, that matches what I saw when I took the tape off the bad repair at the harness end. This connects to ground, so I expect to get a beep to ground when I do a continuity test with this one, and I do, happy days. I think I've read I should get 500ohms when I test the resistance of the other/signal/ wire in this harness, but I don't, I don't get anything, but I do get a beep to ground that I wasn't expecting and according to the wiring diagram this should go back to pin 23,

 

My next plan is a continuity test from pin 23 to the harness, I'm expecting this to fail.

 

Could it be that because I'm getting continuity to ground from the sheild and the signal wire it's fused somewhere?????

 

Is my thinking sound?

 

 

As always thanks in advance

The harness often fails between the plug and the sensor. I deleted mine years ago. Using the harness as a plug in with the 1 Mega Ohm resistor.

Henri's diagnostic here http://zhome.com/ZCMnL/PICS/detonationSensor/detonationSensor.html

His original "how to relocate" (better than just fooling the ECU with the resistor) seems to have dropped off the net but found a pdf of it here http://www.pexcom.com.au/z32cms/e107_images/Z32_Detonation_Sensor_Re-Location.pdf

Plus another version

http://twinturbo.net/nissan/300zx/forums/technical/view/786419/TECH-Detonation-Sensor-Relocation.html

HTH

Thanks guys, I've got bigger issues , I've tried the resistor and that didnt work, I've tested the ECU side of the harness and I think I have a short, so if I do the relocation it won't help, I need to bypass the ECU to the harness with a new piece or trace it out and fix the short which will take ages, or I can pop the resistor in at the ecu end between the signal and one of the earth's, thats probably quickest , then whe. The engine is out fix it properly