Im not really sure where to post this and I doubt anyone here can help with out seeing the car but worth a shot. I have noticed a very slight electrical whine or feedback noise that seems to be constant coming from the right side of the car while Im sitting in the driver seat. Seems to be in the interior. Its faint but actually giving me a solid headache both yesterday and today. Even though I can bailey hear it, its really bothersome but I cant trace the location. I tried searching and am only coming up with the rear axle nut click. Anyone ever hear of something like this before?
Prob have to go to an audio specialty shop I would think huh?

 

Hey, I'll reply since I have the exact same issue (I think). I think our cars (some of them) have bad grounds or some other issue in the ECU (which is located behind and under the glovebox - right side of the car). It creates this constant, 10kHz (very high frequency - like an old CRT TV) tone. I have young, very sensitive ears, so it bothered me enough to go to the dealer first thing when I got mine. I did some research and there are threads which tend to point to the ECU issue. Some cars have it, some don't.

https://www.myg37.com/forums/g37-sed...-the-time.html
https://www.myg37.com/forums/engine-...-noise-15.html
High-Pitched Frequency Update - Page 2 - Nissan 370Z Forum

I went to the dealer, and told them what the issue was based on my research (and was very clear about exactly what frequency it was - it measures 10kHz exactly, which is probably the digital clock timer frequency for the ECU). They took forever to do anything but reached out to Infiniti TechLine and were told that I was right but with those ECUs out of production there was nothing they could do. They offered to use an insulating foam to surround the ECU but that only band aids the situation rather than fixing the root cause, and you run the risk of the ECU overheating. Not a viable solution. A possible solution is to try junkyarded cars' ECUs and hope you find the right model ECU and that it quits ringing, but that's an expensive long shot.

Two workarounds I have are that I usually drive windows down, because I want to listen to my catback. But when I have to keep them shut, I have found a seat position that minimizes the noise. High frequencies like that have short wavelengths (10kHz completes a cycle in about 1.35", meaning in 1.35" it goes from zero to full to zero twice), so as you move your head it should change in volume a lot (especially as it resonates around the cabin - it's not as simple as any 1.35" will make a difference). My seat is as low as can be, and probably halfwayish back but that doesn't matter since I don't know how reclined I am.

 

Dude, I thought no one would reply to this but that is EXACTLY whats going on. Turning my head changes it and so. That's it!
Now I know its the ecu. I can try to figure out what to do. Have you considered running an additional ground to the chassis from the harness? Since I have a RWD sport sedan, might be hard to find another ecu but I do know of a few that have them I can call and get the vins and check the build against mine, which a RWD Sport 6mt sedan I find most are optioned identical.

 

Interesting - mine is 6MT too but it's a 2009 so it's the prefacelift body (and older hardware - red speedo/tach needles and such). I don't think this problem is manual only - there seems to be no consensus as to which model ECUs are problematic and which aren't. Most are listed as discontinued, one listed as being a VQ37 6MT model is just over $1000... https://www.infinitipartsdeal.com/pa...ol_module.html

I would love to try grounding the ECU better, but I don't know for sure that that's the issue, and I'm not 100% sure how to access it to do this. I did try the Black Betty engine grounding kit (search this forum) and got basically no change but of course there's no connection to the ECU.

I'll be super curious to see if you make any progress - please let me know as you try things out on this.

 

So I just found the exact same build a see you in a junkyard. Before I spend 150 bucks I'm gonna try to run a ground from the pin on the harness. Do you know where I can find a schematic letting me know what is the main ground for the ECU?

 

2012 Sedan ECM: https://www.nicoclub.com/service-man...an/2012/EC.pdf
Infiniti Factory Service Manuals (where I got that from): https://www.nicoclub.com/infiniti-service-manuals

Be warned that the FSMs are dense, I haven't put the time in to find it though I'm sure it's roughly similar to the 2009 version. Happy hunting! Edit: plus it might not be in there, but hopefully it is. Let me know if you find the grounding information somewhere else.

 

Subscribed.

Mine does the same exact thing, mine is a 6MT. I've had the car for almost 6 years now and have dealt with it. Annoying but if there is a simple solution I'd definitely be interested in giving it a shot.

 

This weekend Im going to try t run a ground from the harness and will report back

 

So before I ground out the wrong pins. Based on what I see here its these??
Im going to ground out these 4 pins direct to ground

 

Looks good to me - however, you're in uncharted territory so I don't know for sure. Where in the car is this harness and which direction do you plan on getting to it from - is it through the engine bay or glovebox?

 

I was just going to stick four wires into the pins of the harness terminals and bridge them into one to a ground bolt
Just to see if it even works

 

Any luck?

 

Havent got to it yet. Wife is 9 months pregnant and have bigger fish to fry at the moment but still will try if I get some free time but that's challenging at the moment.