The down button on the steering wheel doesnt work. What to look for?

No assumption. There are two buttons labled down on the steering wheel. Underneath there are two labeled up. These are suppose to allow shifting.

I’m thinking that is the audio controls instead .. However you can watch this video to see for yourself - if desired: https://youtu.be/1ERmiovETOU Can also refer to the owners manual .. Now - IF there is a problem with *any of the steering wheel controls* - recommend hands on testing by qualified personnel - possibly a clock spring problem. Good luck with it!

I like the audio feature. But that is not what my lexus has. There are two quarter sizes buttons on each side of the horn."down" and two underneath "up". They are not described in the manual. Internet traffic says they are transmission.

You’re probably right - but it’s difficult to say what the problem is without actual testing - as stated, it might be a clock spring problem but more of the steering wheel controls should be inoperative as well.