Transmission Flare between 3rd & 4th?
 

Hi, I own a 2012 370z with about 4,500 miles on it.

The 7 speed A/T seems to have an occasional issue when I rapidly accelerate from 0-60 (pedal down 3/4 of the way) just as I get up to speed, i start letting my foot off the gas, then the RPM's jumps about 500, then it upshifts to 4th gear. The car is fully warmed up when this occurs.

It only happens if I'm letting my foot off the gas at the precise moment between 3rd & 4th.

If I continue to accelerate (flooring it) it won't happen. It also won't happen when using the paddle shifters in manual mode which leads me to believe it's more of a software issue?

The dealer doesn't know anything about this issue, so I don't want to bring it in without proof (using phone camera to catch the incident)

Is this bad for the transmission? will it get worse or is it just an occasional glitch?

Thanks for any input.

Does it happen when you drive the car for a while, then let it cool off for like an hour, and hop back in and drive?

This is a pretty common issue with the 7AT. MyG37 has lots of discussion about it. I personally experienced the same issue when I had my 09 G37. It seems to be a torque converter locking/unlocking mechanism.

I know Nissan has just released new software update for the G (09, 10, 11, and early 12), not sure about the Z. Ask your local dealer if they know about it.

Where did you learn about the new update? Link?

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I found this NTB12-035.

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Have fun reading the thread:

G37 7speed transmission reprogram... - MyG37

There are actually 3 versions. The 1st one was released early 2009 and was not popular. Then came ITB10-075 in 2010, and recently ITB12-027. Not sure how what the code is for Nissan vehicles.

No, it only happens during a particular stretch of highway which is a slight incline, going up a long straight hill. It is almost as if the car gets confused. Backing off the gas while still in 3rd gear at 6K RPM's, It's like the car realizes "wait, you don't want to go fast anymore?" So it drops into 4th, but more slowly than if I were laying into the throttle. (this is where the 500rpm blip happens)

I've noticed the gears shift really fast .5 seconds when I'm really flooring it, but shift more slowly when I'm driving like an old man. I suppose this makes the shifts smoother, but I'm wondering if by backing off the gas too abruptly at the wrong time, the car is telling me "dude WTF!? do you want fast or slow!" It will hang in 3rd for a second before realizing I don't want the high RPM's anymore.

This is why I think it may just be a glitch in the software.

It could also be some sort of misread on load -- any CEL's?

could it just be the transmission's software that is responsible for matching transmission speed to engine speed (rev-matching). I thought the 7-speed auto had a type of "syncro-rev match" like the manual does . . .

Yes, the A/T has rev matching for downshifts. What I didn't know until recently is that it also rev matches for upshifts as well, so it might be blipping the throttle but no longer giving me the .5 second quick shifts, since I'm backing way off the throttle.

I might just be confusing the transmission as it's changing shift speeds.

No.

:iagree:

Mine does this too I notice. I think with the 7 speeds and all the electronics there are bound to be some hunting, especially if you let your foot off.
For me I'm using the manual shift more and more just because it's more responsive.

What's funny is that my '12 Z seems to have the same issues that the 2009-up G37's had. Severe engine braking during decel, severe 2>1 down shift, and flare during the 3>4 and the 4>5 upshift.

Do I have the same software as the 2009-up G37's? I would think my car has improved software. Can others that have a 7AT confirm this?

You would think that Nissan would have gotten this right after 3 years.

According to the thread, most people see huge improvements and are happy with the latest software. The old software has a huge lag which is fixed in the new one. I rather have the harsh downshift (sport car feel) than the lag.

The 7AT was the main reason I traded my G in for the Z (6MT of course) :P