Over the summer, I had some problems with my transmission shifting up on its own in manual mode, and was told that it was from overheating (it was quite hot out at the time.) Apparently my fluid was rather baked, so added a GTM cooler and had it flushed. It was fine, until recently its been giving me some weird issues. The first thing I noticed was that it took it longer than usual to shift into reverse. Once or twice, its been so long I go to give it a bit of gas and it bangs into gear. Second issue is with downshifting, I notice sometimes it seems to keep the engine rpm wherever it was after downshifting, so it will not slow down at all but keep going. Then again, a few weekends ago I was driving up a back mountain road and it started upshifting in manual mode. It would go from 2 > 3 or 3 > 4 without me telling it to, and then would stay there for a few seconds before it would let me step down again. The longer I left it in the higher gear, the longer it would stay in the lower one before stepping up again. Thing is, it was about 30 degrees out when this was happening, so its hard to believe that it was really overheating. When I had it at the dealer for its 60k, they said they couldn't check the tranny fluid level with the cooler installed. I had the fluid level checked somewhere else before the last incident, so that doesn't seem to be the problem. Called GTM, and they said that the only info they have is that the tranny will go into full limp mode if the fluid temp is over 293 degrees for 2 minutes, or if it breaks 302 degrees. Anyone else have any ideas?

Thanks,
Chris

 

I've experienced this when I started to track the car on HPDE weekends. When the engine got hot it would shift from 4th to 5th on the long straights and not come down more than one gear even if I tried to get it to. I assumed it was in limp mode and lived with it for the next 5 minutes before the session ended. I later installed and engine oil cooler and the problem seem to go away as the engine heat was lower and wasn't also cooking the tranny. My main problem now is that when I brake hard for a corner after a long straight, it still wants to downshift for me, usually from 3rd. to 2nd. before I'm ready. Often I'm in fourth and I want to go down to 3rd. and I blip the paddle only to find out that the tranny already shifted down to 3rd. and now I'm in 2nd. revving the engine near redline and not in the gear I want to be. This even happens on the street sometimes when I'm pressing it. Definitely a programming error on Infiniti's part in how it wants to do the driving for you even in manual mode. Somethings has to be out there to fix this problem.

Al

 

Join the dark side... 6MT. Stay in any gear for however long you want.

 

Yes, I'm used to driving a manual but now I can't because I have a permanent injury on my left foot. My G shifts down to early in manual mode. Still like driving in manual mode though.

 

Interesting. Mine will only shift down if its at the point of being near idle, never had a problem there. The upshifts are where I ran into problems.

Update though, left the car at the dealer while I was away. Fluid was a bit low, but looked pretty bad either way. Did a flush, then ran it and let it mix and did a second flush. Also got the ECM update. So far so good, so we will see what happens next time I push it.

 

I have to same issue w/ my e38 bmw, it only does that when it gets hot, but once cooled it's fine.

 

In manual mode, the transmission downshifts on its own if I'm braking. When I downshift sometimes instead of 5-4 I end up downshifting to 3 because car already downshifted to 4th on its own.

 

In M if its in 5, it will go to 4 on its own? Dang, that's really weird. Mine would only downshift on its own (in manual) if I am too low for that gear to go, which is like 45 for 7, and progressively lower from there. Mine did that in DS, and sometimes I would have it in DS and it would decide to downshift on its own before I hit the paddle so it would end up a gear lower, but never had that in M....