2015 auto transmission shifting issues

I have a dclb 2015 trd sport automatic transmission. And this issue has happened a few times. I just want some feedback. Should I go to the dealership with it. Or can I fix it at home.

So when accelerating normally to highway speed. The transmission will shift up to 3rd. By this time I'm normally at highway speed. But my transmission gets stuck on third. I will be doing 65mph on third truck is at about 3500rpm. And it stays there. I let off the throttle to try to get it to shift. But it takes like 30 seconds befor it finally shifts to 4th. Then it takes another 15 sec. To get to OD. Is this a normal issue?
It doesn't happen all the time. But it did happen this morning. I do have a remote start and I do let my truck warm up befor hitting the road.

 

I would get that checked out by a shop or the dealer. There are a lot of things that can go wrong in an automatic and if you can catch them early you can typically avoid a replacement/rebuild. How many miles are on the truck? If you can figure out how to replicate it than it will be easier to explain to the tech. If this is just an occasional thing maybe the internal clutches are starting to slip.

 

Could be a number of different problems . The A750E is a computer controlled transmission . Scanning for codes is what needs to be done next . Could be as small as a throttle position sensor issue or perhaps a temperature sensor . I will also add that when the transmission is cold , it waits for proper operating temps before overdrive and the torque converter are applied
Here is some information for the transmission in your truck
https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

my truck is about 9 months old. and has about 12k miles

 

Take it in, have them check the fluid level to start. For some reason there's been low fluid levels, took mine in bc it was shifting slightly funky, turned out it was low. Worth checking. I believe there's a thread about it.