I have a 94 g50 base. Lost power, checked codes wouldn't you know it dtc 34. I recently installed new jecs knock sensor so I decided to rule then it.Here's what I've found. When I unplug the sub harness (6 wire plug- bottom 2 dedicated to left and right knock sensor, top 2 dedicated to a coolant temp sensor, then middle 2 dedicated to??????) Now when I unplug the sub harness and check resistance at the sub harness, I get 540 kohms on the right bank (drivers side) and 560 kohms on the left bank (passenger side). If I then jump the connections of the knock sensor and the coolant temp sensor car runs perfect , no codes, no loss of power. Now that's 4 of the 6 connections jumped. As soon as I jump the middle two connections (which I have no idea what they go to) I get knock sensor code and car runs with retarded timing. When I leave the 2 middle connections unplugged , clear the codes then everything is fine. So my question is in the knock sensor sub harness connector can anyone tell what is the wire layout on that 6 wire plug. Thanks in advance.

Welcome to NICO
glad you put JECS ks on, but it's still possible you have a "second" JECS part that was not certified by Nissan for them to put their logo on it.
Possible. otoh, 540k ohm and 560 kohm are reasonable values for the ks when measured quiescently. What you might want to know is what is the resistance vs. frequency response.
on the 6-wire plug, as you look at the 24079-67u00 subharness with the connector tab pointed up, the two ks wires are top/bottom on the left. The two wires for the ECU temperature sensor (not the dash gauge) are top bottom on the right. the two in the middle should just be dead-ended in the subharness.
Not sure what you are saying with the jumping, but it sounds like you are 'fooling' the ECU by putting the temp sensor (k-ohm range) in parallel with the ks (100's of k-ohm range).

Thanks so much for responding. What I meant by jumping it is that I unplug the harness connector and use alligator clips to make the connections between the unplugged harness(clip one end to the male terminal, then clip the other end to the female terminal) It also allowed me to check voltage at the knock sensor. So that's 6 alligator clips in that harness. When I take the alligator clip off the middle bottom terminal (with the connector tab pointed up) everything is fine. So the middle terminals specifically that middle lower one is causing a knock sensor code to trip. I'm so glad you posted a pic of the new harness I'll order one right away. I wired in my new ks but would feel better with a whole new harness. Anyway those 2 middle terminals are dead huh? Thanks for your help.

Also could you tell me where I might be able to purchase 24079-67u00? Thanks again for your help.

Fristim wrote: ↑

Mon May 25, 2020 1:43 am

Also could you tell me where I might be able to purchase 24079-67u00? Thanks again for your help.

I hate to be a downer, but I doubt you'll find that harness anymore, even direct from Japan (unfortunately). Your best bet would be to make one/have one made.
But I'm also not hearing (board posts are not always perfectly clear) that the harness is your problem.

Yes, I think you're correct about the harness not being my problem. However I sure would like to know for sure what those two middle terminals are (supposed to be) for. There are two wires that go into the harness connector (i.e. from the female side of the 24079-67u00 connector) and 2 wires coming out of the connector that you say dead end in the harness any idea what they might have been for!

On my 95 Q$%, I jury-rigged it by wiring two KS in-line with the old ones off the KS/engine coolant temp sensor connector. I then mounted them on a piece of aluminum which bolts onto one of the plenum top bolts. With the unavailability of parts required to change the KS (like the hoses and gaskets necessary for a plenum R/R), I really wasn't left much choise. I figure that a long as i use premium unleaded fuel, I should be ok. It's been that way for almost 6 months, and the car runs like a champ still. With the lack of parts availability, I figure I'll just keep driving it until it stops running and then bid it farewell.