i have 2015 Lexus IS 250
and the volume **** is kinda glitchy ( when i try to turn the volume up it starts going up and down until eventually i achieve my wanted level ) same goes if i want to turn it down
however the volume button on the steering works fine

 

Get some electronics contact cleaner. Spray down in where the ***** turns. If not you can use light Alcohol. Turn back and 4th 360, about 30 plus times. The Volume control is a Pot. Grit. grime and dirt get in there.