I have a 2011 Lexus IS 350 AWD. I’ve noticed ever since I got the car a couple months ago it will downshift from 6-4 or 5-4 gear. But today the car downshifted from 5-3 gear and it wouldn’t upshoft on its own. I couldn’t get it to happen again but now I’m super paranoid. Is this normal? I really don’t want to have to throw a transmission into a car I’ve only had for less than 3 months!

 

Check the fluid level. It may be low