According to the Dealer there isn't a verbal command and has to be done through touchpad. I'm not convinced. Going to practice my American/Japanese accent and keep trying.
Just had the same problem with my month old UX. Dealer said gas level was low and topped up but couldn't find any leaks. Put in a tracer dye and I have to go back if air con doesn't improve.
I find it perplexing (to put in mildly) that Toyota cars have a 5 year superior warranty whilst Lexus owners have a 3 year warranty to be followed by, if the posts on here are correct, an inferior warranty.