Its a sunny 90 degree day and I'm on a drive in my G. In D not driving aggressively. I come to a round about and stop to let traffic clear. I enter the round about giving it 1/4 throttle and then let off the gas to coast around the curve. When I reapplied the gas the rpms rose as if the car was in N before slamming into a random gear. There was a burning smell following this which I would guess was transmission fluid. What just happened to my car?

 

Curve = centrifugal force. And you are sure your trans fluid is the correct level?

Only postulation I can think of.

Coop

 

Did you ever figure this out? My car is doing almost the exact same thing without the traffic circle. I'll ease up to a stop sign with my foot off the gas. Without coming to a full stop, I'll accelerate and for a split second the engine revs way up like the tranny's in neutral and then BANG, it slams into gear, snapping my neck back and chirping the tires. Seems much more prone to this when the engine's cold. Any ideas?

 

that has happened to me about 5 times or so. It happened to me more after I give it a good amount of gas, then let off, then re-apply. It acts like it is in N for a second and then engages with a chirp of the back wheels....

 

5 or 7AT?

Year?

 

sorry - 2008, 5spd AT, RWD EX35 (same tranny as 2008 G35)

 

That happens in my 7at sometimes..

 

7AT, 2011 Journey Coupe. It seems to do this only when cold. "Can't duplicate" when it gets warm - meaning I won't be able to demo the issue at the dealer's service center. It's pretty annoying and I'm afraid that someone not familiar with the issue will lunch my rear end or, worse, coast to a near stop and then stand on the thing, only to wind up fishtailing into a ditch.

 

If you enter a turn aggressively, the trans down shifting to lower gear anticipating "sporty" driver to pounce out of the turn. The problem is from time to time it messed up shifting to too low of a gear and then fighting with the VDC switching the power on and off. My 09 almost eliminates all these problems after trans reflash.

 

I had the same issue pulling up to a stop sign and not coming to a complete stop. Put my foot on the gas again and it revved like it was in neutral and lunged forward into gear. I had just serviced my car and had a transmission flush before this happened and when I took my car back to the dealer they said that there was air in the lines causing the issue. Hasnt happened again since.

 

I had this problem on a '11 G37x sedan and what fixed it for me was the 027 TSB (ECU/TCM reprogram).

You'd never toast AT fluid with just one soft/goofy shift - it actually takes quite a bit of heat for quite some time to do that. Plus, even if you did, you'd never smell it.

 

Its a rev matching feature, It downshifts and revs-up sometimes like you are in DS mode but if your timing is right on (or off for this matter) it will have a hard shift. It is hard to duplicate because you need to have an exact kind of breaking and accelerating as it is changing gears automatically. Or at least that's what it sounds like.

This will usually happen under moderate breaking to change instantly to acceleration. Doesn't have to be hard acceleration just any kind of acceleration.

It is just how the Rev matching thing works.

If you change to manual mode and downshift when you are doing about 3000rpms then you should hear the same noise. If this matches the sound your hearing then the above will be correct.

Hope this helps