YES YES YES!! Tiger is right! His technique is exactly right! You can really hear it especially loudly when you look left. Your ears do ring for quite awhile when getting out of the car. That can't be good. I love this car except for that problem. I have an '09 Infiniti FX35 that doesn't make that noise. I bought my car in Feb. I don't feel like walking outside to check my exact build date. I would think it was buit in late Fall of '08.

No one has mentioned the HID lights ballast. The Xenon lights are High Intensity Discharge lights which require a high voltage, which is created by a ballast. Modern day ballasts are electronic (sometimes also referred to as digital) and can operate at frequencies in the 10s of kilohertz range. From the research I've done it looks like most vehicle HID ballasts operate in the 450hz range, which is more along the lines of bass than a high pitched sound, however, if the ballast does in fact operate at a higher frequency and there's a grounding issue the noise could possible show up in a variety of places. The most likely would be speakers.

While the fuel pump is a likely problem, I'm not sure it would create a resonance frequency of around 20khz, the frequency where human hearing cutoffs and appears to be the sound that people are hearing.

If the ECU is also operating at a frequency in the same range it could also create the problem if there's a grounding problem, it's just that ECU's operate at a low voltage and I would think it's too small to create the issue at hand.

This is all speculation and guesses, but figured I'd throw it out there.

after spending some time reading about it here and on various G37 sites, I don't think there's any question its the ECU. On some Infinity sites it said the dealers tried to fix it by wrapping the ECU in sound deadening material, but did not do it too much so that it would overheat. Results were so-so. On threads on this site some posters have had the dealers diagnose it as the ECU. Its the ECU.

Simple solution, take out the ECU and see if it goes away :happydance:

BULLETIN POSTED ------------------------------------------
ECU being replaced....NICE !!!!

I hope you're joking. If you're not joking then it is people like you that have given America a "mad litigation label".

of course i'm joking

I have 1800 miles on my car and no noises or rattles.

Bought my Z back in Jan and never really heard it myself. However, my girlfriend hears it and it drives her crazy. I probably can't hear it due to working out in the flightline for 3+ years. Jet engine noise > car engine noise.

Nissan has a few bugs to sort out, it seems. They've corrected some/most of the 350 ones, but new ones are popping up in the 370. They should hire a Toyota engineer to help 'em with it!
__________________________________________________ __________________________________________________ ____________
Bone stock '04.5 Touring Coupe: No feathering, no starting issues, no oil-consumption issues, flawless AT...S-w-e-e-t ride!

explain...

Hi-
Thanks for the info.
I have a 2009 EX35 JOURNEY AWD with full electronics/nav/Bose package.
Just yesterday the high pitch whining began on my ride home from work. I have excellent hearing so it is extremely distracting and irritating.
I immediately hit the Net and found a boat load of posts. It seems that you nailed the fix.
I of course called my dealer - Infiniti of Englewood - and needless to say the service manager "never" heard of this issue.
I called the finance manager whom I have a good rapport with and simply insisted that they order an ECU replacement. Overall, I am mostly pleased with the car but it clearly has some blatant shortcomings such as poor gas mileage (which I kind of expected) and poor seat warmers. The back hatch should be automatic too.
If the FX35 was more in the ballpark for me - I would have just bought that instead.
I did not expect a perfect product but 1700 miles is a bit on the early side to begin the process of working out the annoying bugs and ticks.[/B]

Hi-
Thanks for the info.
I have a 2009 EX35 JOURNEY AWD with full electronics/nav/Bose package.
Just yesterday the high pitch whining began on my ride home from work. I have excellent hearing so it is extremely distracting and irritating.
I immediately hit the Net and found a boat load of posts. It seems that you nailed the fix.
I of course called my dealer - Infiniti of Englewood - and needless to say the service manager "never" heard of this issue.
I called the finance manager whom I have a good rapport with and simply insisted that they order an ECU replacement. Overall, I am mostly pleased with the car but it clearly has some blatant shortcomings such as poor gas mileage (which I kind of expected) and poor seat warmers. The back hatch should be automatic too.
If the FX35 was more in the ballpark for me - I would have just bought that instead.
I did not expect a perfect product but 1700 miles is a bit on the early side to begin the process of working out the annoying bugs and ticks.[/B]

I've just recently experienced this. It started out of no where. However, I was able to pull over, shut down the car, and start it back up and it the sound disappeared. Is there really a bulletin for a warranty replacement?

I already took my Z in to get the high pitched noise from the front, now it's coming from the back of the car, another ECU problem, i am so frustrated.