Shifts into highest gear only when trans operating temp is reached
 

Before my car (specifically the trans) reaches full operating temperature, it will not shift into the highest gear. So I get on the highway, get her up to 60mph, which is usually 2000 rpm, and she revs at about 2200-2300. Usually within a few miles of driving, it'll shift into high gear. This phenomenon is directly related to the outside ambient temperature, which makes me think it's directly related to the transmission operating temperature. During the warm summer months, it sometimes shifts into high right away, and if not right away, usually within about one mile of driving. In the winter though, it can sometimes take five miles or more. It's positively related to the operating temperature of the transmission. This has been happening for years now and I see no other adverse effects occuring due to this issue. Trans doesn't slip at all, fluid is the right color/smell, the only other thing I see affected might be my fuel mileage, due to the higher rpms. I did recently replace the speed sensor due to the other usual issues related to that sensor. Those problems came and went when the sensor was replaced. Thank you!

Thanks for your help? Do you have an idea of what potential issues I'm dealing with here?

If I'm understanding you correctly, that car won't shift into fourth gear until it's at normal operating temperature, than that's functioning as designed. My 2004 I35 does the same thing & back in the 1990's my parents had a 1989 Maxima that also did that. There are other older threads on here about it & the reasons for it, you might be able to find them with a search.

yes that is normal operation especially when it gets colder, ive had about 2 or 3 nissans that did the same thing. Once the transmission is warm, it will shift into the overdrive, or that last gear.

Well I'll be darned. I did not know that. Thank you all who replied. Not the answer I was expecting! Glad to know it's working properly. Seems strange to me though, I've never been in another vehicle that operates that way, to my knowledge. Cheers!

Nor have I. I'm no fluid dynamicist, so I can't speak on the effects of ATF or other fluid viscosities or properties or any of that scientifical stuff, but that seems like a bad design. Every single automatic I've ever driven in the past, from Hondas, Chevys, to Mercedes S Classes have shifted through the appropriate gears whether 2 minutes after driving in 25 degree Denver weather or 116 degree Phoenix weather. Your symptoms seem anomalous, and your intuition is speaking to you.

My I35 was the same when cold. It surprised me at first; much different behavior than my Hondas.

I knew my intuition was sometimes correct. Happy I'm not alone in my thinking! Is it possible that Nissan is the only car manufacturer EVER to be designed this way?

when your speed sensor was bad did it sorta slip and not shift up from 2nd when hot?

The speed sensor - I only had problems on really hot days, 90+ weather, where the trans would start slipping into neutral while driving. It also would shift really hard if it shifted at all. I would have to let it cool down before I was able to continue driving. The new speed sensor fixed that. Super easy fix for anyone preparing to do theirs.