Transmission downshifting

My '14 Taco is downshifting way to much on small declines, then it has a problem shifting back into drive so I do it manually. It also shifts hard into D after it has downshifted going down a hill. It has also failed a couple of time to shift into D so I've done it manually. It never did these thing when it was new but as the miles have piled up it seems to be getting worse. It's going into the Stealers on Tuesday. Any thoughts?

 

A lot of the autos have had low fluid from the factory. Dont try this yet because youre going to the dealer, but disconnecting the battery for a while will reset the learned driving pattern. You could see if it drives 'normal' after that. Mine shifts hard also. The downhill shift is a 'feature' of downhill assist. It gets annoying.

 

You could try what I do. Pop the tranny in neutral, while in neutral then hit the brakes. With your foot still on the brakes put it back in drive. Now as long as you keep your foot on the brakes, it will not downshift. Try it.